Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function....Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.展开更多
OBJECTIVE To investigate the intervention effects of tissue-bone homeostasis manipulation(TBHM)on peripatellar biomechanical parameters and knee joint function in knee osteoarthritis(KOA)patients.METHODS Sixty patient...OBJECTIVE To investigate the intervention effects of tissue-bone homeostasis manipulation(TBHM)on peripatellar biomechanical parameters and knee joint function in knee osteoarthritis(KOA)patients.METHODS Sixty patients with KOA(Kellgren-Lawrence gradeⅡ-Ⅲ)were recruited from the Acupuncture-Moxibustion Rehabilitation Department,Anhui University of Chinese Medicine between October 2024 and May 2025.Participants were randomized into a TBHM group(n=30)or a transcutaneous electrical neuromuscular stimulation(TENS)group(n=30).Using two-way repeated measures ANOVA,biomechanical indicators,including rectus femoris tension,vastus medialis tension,vastus lateralis tension,patellar ligament tension,lateral patellar displacement(LPD),medial patellar displacement(MPD),normalized patellar mobility(LPD/patellar width[PW],MPD/PW),knee flexion range of motion,and functional indicators,including KOOS subscales,time up and go test(TUGT),were compared between groups at baseline and after 6 weeks of intervention.RESULTS After intervention,all biomechanical and knee joint function indicators in the TBHM group were significantly improved(P<0.05,P<0.01),while only the vastus medialis tension,TUGT and KOOS Pain,ADL and QoL scores in the control group were significantly improved(P<0.01).The improvement amplitudes of biomechanical indicators in the TBHM group,including rectus femoris tension,vastus lateralis tension,patellar ligament tension,MPD/PW,LPD/PW and knee flexion range of motion were better than those in the control group(P<0.05,P<0.01).In the functional evaluation,the interaction effects of the TBHM group in all dimensions of the KOOS score and TUGT were statistically significant(P<0.05,P<0.01).Post-hoc simple effect analysis confirmed that there were significant differences in the above indicators between the two groups after intervention(P<0.05),and all indicators showed a significant main effect of time(P<0.01),suggesting that the intervention measures had continuous and cumulative curative effects.CONCLUSION TBHM effectively improves joint function and quality of life in KOA patients by restoring dynamic equilibrium in soft tissue tension and patellar mobility,ultimately achieving the therapeutic goal of concurrent tissue-bone management.展开更多
Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important...Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important role in soil stabilization and fixation,as they resist soil erosion and shallow landslides in this area.However,the biomechanical properties of the roots of dominant herbs and their influencing factors in this area remain poorly understood.Therefore,we selected two dominant herbs in this area,Stipa aliena Keng and Poa crymophila Keng,and carried out a series of uniaxial tensile tests on the roots of the two herbs under different treatments.Meanwhile,the effects of root diameter,plant species,gauge length,root water content,and loading rate on the biomechanical properties of the two herbs'roots were analyzed.The results showed that root diameter was the most significant factor affecting the root biomechanical properties(P<0.010),and root tensile force displayed a positive power law relationship with root diameter,whereas root tensile strength and Young's modulus followed negative power law correlations with root diameter,and fracture strain increased linearly with root diameter.Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater than those of P.crymophila(P<0.001),which was mainly due to the higher lignin content and lignin:cellulose ratio of S.aliena roots.During uniaxial tensile process,hydrated roots exhibited elastic-plastic-brittle behavior,whereas dried roots exhibited elastic-brittle behavior.Root fracture strain of the two herbs was significantly lower under 100 mm gauge length than under 50 mm gauge length(P<0.001),and the Young's modulus was significantly greater(P<0.050).Tensile strength and fracture strain of hydrated roots of the two herbs were significantly greater than those of dried roots(P<0.050),whereas the Young's modulus was significantly lower(P<0.001).Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater under 20 mm/min loading rate than under 200 mm/min loading rate(P<0.050),whereas loading rate had no significant effect on the root biomechanical properties of P.crymophila(P>0.050).Fibrous roots of the two herbs were well developed,with relatively high tensile strengths and Young's moduli of 78.498 and 837.901 MPa for S.aliena,and 67.541 and 901.184 MPa for P.crymophila,respectively.The two herbs can stabilize soil and prevent soil erosion and can be used as pioneer species for ecological restoration in the upper reaches of the Yellow River.These results provide a theoretical basis for soil erosion and shallow landslide control in the giant landslide area of the upper reaches of the Yellow River.展开更多
Flexible and wearable electronics are attracting surging attention due to their potential applications in human health monitoring and precision therapies.Safety hazards including strong magnetic field and electric lea...Flexible and wearable electronics are attracting surging attention due to their potential applications in human health monitoring and precision therapies.Safety hazards including strong magnetic field and electric leakage are big risk factors for human health.It remains challenging to develop self‐powered and wearable safety hazard sensors that could not only be able to monitor human motions but also have functions for detecting potential hazards.In this work,we fabricated a self‐powered,shapeable,and wearable magnetic triboelectric nanogenerator(MTENG)based on ferrofluid,Ecoflex,and carbonized silk fabric that possessed effective hazard prevention and biomechanical motion sensing ability.A peak open‐circuit voltage of 0.7 V and short‐circuit current of 10μA m^(−2)can be achieved when magnetic field is changed between 3.5 and 37.1 mT.As a component of triboelectric layer of the MTENG,ferrofluid can substantially extend the range of its sensing capabilities to many hazardous cues such as dangerous magnetic field.Furtherly,the developed multifunctional and self‐powered sensor can be used to monitor human activities such as drinking water and bending finger.This effort opens up a new design opportunity for hazard avoidance wearable electronics and self‐powered sensors.展开更多
In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment si...In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment simulation,particularly of the mechanical microenvironment,is crucial for estimating the biological effects of a tumor.However,current in vitro osteosarcoma model construction is often limited to a single mechanical signal,which fails to simulate the diversity of osteosarcoma mechanical stimuli.In this study,we utilized embedded bioprinting technology and the multiple response properties of calcium ions in soft and hard stiffness systems with osteosarcoma cell biological functions to construct an integrated gradient biomechanical signal-tailored osteosarcoma model(IGBSTOM).We achieved this by printing a fibrinogen bioink containing calcium ions and osteosarcoma tumor spheroids within an extracellular matrix composed of methacryloylated alginate,methacryloylated gelatin,thrombin,and transglutaminase,which is rich in polysaccharides and proteins and exhibits self-healing properties.Our in vitro and in vivo studies showed that the IGBSTOM enhanced tumor stemness,proliferation,and migration,and successfully reproduced the nest-like structure of tumors,providing an in vitro research platform that is more similar to the natural tumor than the existing models.This study proposes a novel IGBSTOM construction and provides a new strategy for the clinical understanding of tumor development,drug screening,and exploration of drug resistance and metastasis mechanisms.展开更多
Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was ap...Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was applied to stent strut designs and thoroughly evaluated through various computational simulations to assess their potential to enhance the mechanical performance of WE43 magnesium alloy stents.Connected elliptical structures with a vertical-to-horizontal length ratio of 1:1.8 were incorporated in varying numbers and then compared to conventional laser-cut stents using 3-point bending,crush,crimping,and expansion tests,internal carotid artery insertion simulations,and computational fluid dynamics analyses.The results demonstrated that the biomimetic stents exhibited significantly improved stress distribution and reduced applied stress while maintaining hemodynamic stability.Computational fluid dynamics simulations further confirmed that the biomimetic could reduce wall shear stress and improve blood flow,thereby potentially minimizing the risk of restenosis and thrombosis.These findings suggest that diabolical ironclad beetle-inspired stent structures may offer enhanced biomechanical performance and clinical safety in magnesium-based endovascular interventions.展开更多
AIM:To investigate the relationship between preoperative corneal biomechanical properties and corneal tomographic properties in cataract patients.METHODS:The study consisted of 59 eyes of 30 participants who were diag...AIM:To investigate the relationship between preoperative corneal biomechanical properties and corneal tomographic properties in cataract patients.METHODS:The study consisted of 59 eyes of 30 participants who were diagnosed as cataract in Peking University Third Hospital between September 2019 and November 2019.Stepwise multivariable linear regression analysis was calculated to determine the relationship between corneal biomechanical parameters and tomographic parameters.The patients were classified into three groups of with the rule(WTR)astigmatism,against the rule astigmatism and oblique astigmatism.And the differences in corneal parameters among different groups were compared.RESULTS:There were significant differences in the first applanation time(A1T),the first applanation length(A1L),corneal velocity during the first applanation(Vin),the second applanation time(A2T),highest concavity(HC)radius,displacement amount(DA),DA ratio,stiffness parameter A1(SPA1)and integrated radius(IR)between oblique astigmatism patients and the other two groups.Total corneal steep meridian(K2)was negatively associated with A1L,A1T and corneal velocity during the second applanation(Vout).Patients with higher anterior corneal curvature had lower HC radius and central corneal thickness(CCT;P=0.001 and 0.006,respectively),while the Ambrosio relational thickness to the horizontal profile(ARTh)was higher than those with lower anterior corneal curvature(P=0.009).CONCLUSION:The study reveals that the elasticity of corneal collagen fibers is greater,but the viscoelasticity of cornea is smaller in patients with oblique astigmatism.There is no significant difference in ARTh between patients with different types of astigmatism,that is,the corneal biomechanical specificity of oblique astigmatism group is probably not caused by corneal thickness.Moreover,we find patients with higher anterior corneal curvature has lower HC radius and CCT but higher ARTh than those with lower anterior corneal curvature.展开更多
[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of...[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.展开更多
OBJECTIVE:To investigate the site specificity and differences of the Hegu(LI4)located on the midpoint of the second metacarpal and the point where the bases of the first and second metacarpal bones on the dorsum was h...OBJECTIVE:To investigate the site specificity and differences of the Hegu(LI4)located on the midpoint of the second metacarpal and the point where the bases of the first and second metacarpal bones on the dorsum was historically used as Hegu(LI4)in Japan,through morphological,biomechanical,and histological analyses.METHODS:We defined distally located Hegu(LI4)as Hegu(LI4)-D and proximally located Hegu(LI4)as Hegu(LI4)-P.The distance from the skin surface to the blood vessels as well as the biomechanical properties of the two Hegu(LI4)samples were measured using an ultrasound device and Myoton PRO(Myoton AS,Tallinn,Estonia),respectively,in 20 healthy adult volunteers.Sympathetic fibers under the two Hegu(LI4)samples were histologically observed using tyrosine hydroxylase(TH)immunostaining in 10 cadavers.RESULTS:Hegu(LI4)-D was classified into type 1 with blood vessels<4 mm away from the skin surface,and type 2 with blood vessels>10 mm away from the skin surface.In Hegu(LI4)-P,blood vessels were approximately 10 mm away from the surface.Further,Hegu(LI4)-P had significantly higher tone,stiffness,and elasticity than Hegu(LI4)-D(P<0.0001).TH-positive fibers were present near the artery in Hegu(LI4)-P.CONCLUSION:Hegu(LI4)-D and Hegu(LI4)-P differed in terms of hardness and the distance between the skin surface and blood vessels.Furthermore,sympathetic nerve fibers were present near the artery in Hegu(LI4)-P.Taken together,these results suggest that there is site specificity of morphological,biomechanical,and histological differences between the Hegu(LI4)-D and Hegu(LI4)-P.展开更多
Biomechanical study of the visual system by ocular response analyzer investigates the inter-structural biological relationships,mechanics,and function of the visual system.This review aimed to investigate the changes ...Biomechanical study of the visual system by ocular response analyzer investigates the inter-structural biological relationships,mechanics,and function of the visual system.This review aimed to investigate the changes in corneal biomechanical parameters with age and sex.The articles published in PubMed between 2000 and 2021 were investigated and critiqued,and valid scientific evidence was collected,reviewed and concluded according to the inclusion and exclusion criteria.Most studies showed that corneal biomechanical changes occur infrequently in children up to the age of 20y,and with increasing age and wider age range,there was a significant decrease in corneal biomechanical indices,especially corneal hysteresis.In children and adults,most studies have shown that these biomechanical indicators,especially corneal resistance factor,were higher in females.Although hormonal changes may contribute to this finding,the role of axial length and other biometric indicators should not be ignored.The axial length,the intraocular pressure,and the corneal thickness are other factors associated with biomechanical parameters that should be taken into account in clinical diagnosis and management especially for patients undergoing refractive surgery as well as keratoconus patients.展开更多
Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively infe...Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively inferior performance compared to traditional metal stents with identical structural characteristics.Therefore,improving their mechanical properties is a key issue in the development of biodegradable magnesium alloy stents.In this study,three new stent structures(i.e.,stent A,stent B,and stent C)were designed based on the typical structure of biodegradable stents.The changes made included altering the angle and arrangement of the support rings to create a support ring structure with alternating large and small angles,as well as modifying the position and shape of the link.Using finite element analysis,the compressive performance,expansion performance,bending flexibility performance,damage to blood vessels,and hemodynamic changes of the stent were used as evaluation indexes.The results of these comprehensive evaluations were utilized as the primary criteria for selecting the most suitable stent design.The results demonstrated that compared to the traditional stent,stents A,B,and C exhibited improvements in radial stiffness of 16.9%,15.1%,and 37.8%,respectively;reductions in bending stiffness of 27.3%,7.6%,and 38.1%,respectively;decreases in dog-boning rate of 5.1%,93.9%,and 31.3%,respectively;as well as declines in the low wall shear stress region by 50.1%,43.8%,and 36.2%,respectively.In comparison to traditional stents,a reduction in radial recoiling was observed for stents A and C,with decreases of 9.3% and 7.4%,respectively.Although there was a slight increase in vessel damage for stents A,B,and C compared to traditional stents,this difference was not significant to have an impact.The changes in intravascular blood flow rate were essentially the same after implantation of the four stents.A comparison of the four stents revealed that stents A and C exhibited superior overall mechanical properties and they have greater potential for clinical application.This study provides a reference for designing clinical stent structures.展开更多
Due to the lack of human avoidance analysis,the orthosis cannot accurately apply orthopedic force during orthopedic,resulting in poor orthopedic effect.Therefore,the relationship between the human body’s active avoid...Due to the lack of human avoidance analysis,the orthosis cannot accurately apply orthopedic force during orthopedic,resulting in poor orthopedic effect.Therefore,the relationship between the human body’s active avoidance ability and force application is studied to achieve accurate loading of orthopedic force.First,a high-precision scoliosis model was established based on computed tomography data,and the relationship between orthopedic force and Cobb angle was analyzed.Then 9 subjects were selected for avoidance ability test grouped by body mass index calculation,and the avoidance function of different groups was fitted.The avoidance function corrected the application of orthopedic forces.The results show that the optimal correction force calculated by the finite element method was 60 N.The obese group had the largest avoidance ability,followed by the standard group and the lean group.When the orthopedic force was 60 N,the Cobb angle was reduced from 33.77°to 20°,the avoidance ability of the standard group at 50 N obtained from the avoidance function was 20.28%and 10.14 N was actively avoided.Therefore,when 50 N was applied,60.14 N was actually generated,which can achieve the orthopedic effect of 60 N numerical simulation analysis.The avoidance effect can take the active factors of the human body into consideration in the orthopedic process,so as to achieve a more accurate application of orthopedic force,and provide data reference for clinicians in the orthopedic process.展开更多
Cage plus plate(CP)and zero-profile(Zero-P)devices are widely used in anterior cervical discectomy and fusion(ACDF).This study aimed to compare adjacent segment biomechanical changes after ACDF when using Zero-P devic...Cage plus plate(CP)and zero-profile(Zero-P)devices are widely used in anterior cervical discectomy and fusion(ACDF).This study aimed to compare adjacent segment biomechanical changes after ACDF when using Zero-P device and CP in different segments.First,complete C1—C7 cervical segments were constructed and validated.Meanwhile,four surgery models were developed by implanting the Zero-P device or CP into C4—C5 or C5—C6 segments based on the intact model.The segmental range of motion(ROM)and maximum value of the intradiscal pressure of the surgery models were compared with those of the intact model.The implantation of CP and Zero-P devices in C4—C5 segments decreased ROM by about 91.6%and 84.3%,respectively,and increased adjacent segment ROM by about 8.3%and 6.82%,respectively.The implantation of CP and Zero-P devices in C5—C6 segments decreased ROM by about 93.3%and 89.9%,respectively,while increasing adjacent segment ROM by about 4.9%and 4%,respectively.Furthermore,the implantation of CP and Zero-P devices increased the intradiscal pressure in the adjacent segments of C4—C5 segments by about 4.5%and 6.7%,respectively.The implantation of CP and Zero-P devices significantly increased the intradiscal pressure in the adjacent segments of C5—C6 by about 54.1%and 15.4%,respectively.In conclusion,CP and Zero-P fusion systems can significantly reduce the ROM of the fusion implant segment in ACDF while increasing the ROM and intradiscal pressure of adjacent segments.Results showed that Zero-P fusion system is the best choice for C5—C6 segmental ACDF.However,further studies are needed to select the most suitable cervical fusion system for C4—C5 segmental ACDF.Therefore,this study provides biomechanical recommendations for clinical surgery.展开更多
AIM:To assess the visual outcomes and corneal biomechanical properties of myopia patients between laser in situ keratomileusis(LASIK)and LASIK combined with accelerated corneal crosslinking(LASIK Xtra).METHODS:This pr...AIM:To assess the visual outcomes and corneal biomechanical properties of myopia patients between laser in situ keratomileusis(LASIK)and LASIK combined with accelerated corneal crosslinking(LASIK Xtra).METHODS:This prospective study analyzed 52 consecutive myopia patients treated with LASIK Xtra and 45 consecutive myopia patients treated with LASIK.Only the right eyes in the two groups were analyzed.The uncorrected distance visual acuity(UDVA),keratometry values,postoperative central corneal thickness(CCT),corneal demarcation line depth,the corneal compensated intraocular pressure(IOPcc),Goldmann-correlated IOP(IOPg),corneal resistance factor(CRF)and corneal hysteresis(CH)from Ocular Response Analyzer(ORA)were analyzed.Further,the correlation between the demarcation line depth and ORA-related biomechanical parameters were analyzed.RESULTS:No significant differences in UDVA,postoperative CCT,or mean K values were found between the 2 groups at 1 to 12mo postoperative follow-up(all P>0.05).The changes of CRF was significantly lower in the LASIK Xtra group compared to the LASIK group(all P<0.05)at all the postoperative visits.The changes of CH were significantly higher in the LASIK Xtra group(all P<0.05).No significant differences were discovered regarding the changes of IOPcc and IOPg posperatively(all P>0.05).Out of 52 cases in the LASIK Xtra group,the demarcation line was present in 40 eyes(77%).The average depth of the demarcation was 220.73±42.70μm(136 to 288μm).No significant correlation was observed between the depth of the demarcation line and any of the ORA-related biomechanical parameters such as IOPcc,IOPg,CRF and CH at 12mo(all P>0.05).CONCLUSION:Both procedures demonstrate comparable outcomes in terms of visual acuity,refraction and ablation predictability.This study confirms that corneal biomechanical properties of the included patients weakened after both procedures,but the cornea after LASIK Xtra are stiffer than conventional LASIK.展开更多
AIM: To investigate the short and long term corneal biomechanical changes after overnight orthokeratology(OK) and compare them with those occurring in subjects not wearing contact lenses.METHODS: Retrospective case co...AIM: To investigate the short and long term corneal biomechanical changes after overnight orthokeratology(OK) and compare them with those occurring in subjects not wearing contact lenses.METHODS: Retrospective case control study enrolling 54 subjects that were divided into three groups 18 subjects each: control group(CG), short term(15 nights) OK(STOK) group, and long term(more than 1 y of OK wear) OK(LTOK) group. Corneal biomechanics were characterized using the Cor Vis? ST system(Oculus), recording parameters such as time [first/second applanation time(AT1, AT2)], speed [velocity of corneal apex at the first/second applanation time(AV1, AV2)], and amplitude of deformation(AD1, AD2) in the first and second corneal flattening, corneal stiffness(SPA1), biomechanically corrected intraocular pressure(b IOP) and corneal(CBI) and tomographic biomechanical indices(TBI).RESULTS: Significantly lower AD1 and standard deviate on of Ambrosio’s relational average thickness related to the horizontal profile(ARTh) values were found in the OK groups compared to CG(P<0.05). Likewise, significantly higher values of CBI were found in STOK and LTOK groups compared to CG(P<0.01). No significant differences between groups were found in integrated radius index(P=0.24), strain stress index(P=0.22), tomographic biomechanical index(P=0.91) and corneal stif fness parameter(SPA1, P=0.97). Significant inverse correlations were found between corneal thickness and CBI in STOK(r=-0.90, P<0.01) and LTOK groups(r=-0.71, P<0.01).CONCLUSION: OK does not seem to alter significantly the corneal biomechanical properties, but special care should be taken when analyzing biomechanical parameters influenced by corneal thickness such as amplitude of deformation, ARTh or CBI, because they change significantly after treatment but mainly due to the reduction and pachymetric progression induced by the corneal molding secondary to OK treatment.展开更多
Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relat...Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relationship with the physiological responses of the therapy.So far,however,there has not been a unified approach to standardize these biomechanical characteristics.In fact,it is still undetermined how they affect the observed clinical outcomes of spinal manipulation.This study,therefore,reviewed the current body of literature to explore these dosage parameters and evaluate their significance,with respect to physiological and clinical outcomes.From the experimental studies reviewed herein,it is evident that the modulation of manipulation’s biomechanical parameters elicits transient physiological responses,including changes in neuronal activity,electromyographic responses,spinal stiffness,muscle spindle responses,paraspinal muscle activity,vertebral displacement,and segmental and intersegmental acceleration responses.However,to date,there have been few clinical trials that tested the therapeutic relevance of these changes.In addition,there were some inherent limitations in both human and animal models due to the use of mechanical devices to apply the thrust.Future studies evaluating the effects of varying biomechanical parameters of spinal manipulation should include clinicians to deliver the therapy in order to explore the true clinical significance of the dose-response relationship.展开更多
The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous scr...The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.展开更多
AIM： To compare the changes in corneal biomechanics measured by ocular response analyzer （ORA） after 2.2-ram microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS： The prospectiv...AIM： To compare the changes in corneal biomechanics measured by ocular response analyzer （ORA） after 2.2-ram microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS： The prospective nonrandomized study comprised eyes with cataract that had 2.2-mm coaxial microincision or 3.0 -mm standard incision phacoemulsification. The corneal hysteresis （CH）, corneal resistance factor （CRF）, corneal-compensated intraocular pressure （IOPcc） and Goldmann-correlated intraocular pressure （IOPg） were measured by ORA preoperatively and at ld, 1-, 2-, 3- and 4-week postoperatively. Results were analyzed and compared between groups. RESULTS： In both groups, CH decreased in the immediate postoperative period （P〈0.05）, returned to the preoperative level at one week （P =0.249） in the 2.2-mm group, and at two weeks in the 3.0-mm group （P --0.264）; there was no significant change in CRF values. In 2.2-mm group, mean IOPcc and IOPg increased at ld postoperatively （both ,P〈0.05）, and returned to preoperative level at one week （,0 =0.491 and P =0.923, respectively）. In 3.0-mm group, mean IOPcc and IOPg increased at ld and lwk postoperatively （P =0.005 and ,P =0.029, respectively）, and returned to preoperative level at 2wk （P =0.347 and P =0.887, respectively）. CONCLUSION： Significant differences between preoperative and postoperative corneal biomechanical values were found for CH, IOPcc and IOPg. But the recovery time courses were different between the two groups. The 2.2-mm coaxial microincision cataract surgery group seemed recovery faster compared to the 3.0-mm standard coaxial phacoemulsification group.展开更多
Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sour...Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sources at distances of 40,44,and 48 cm from rats;and examine the changes in the gross anatomy of the lungs,lung wet/dry weight ratio,hemoglobin concentration,blood gas analysis,and pathology.Results Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance.The lung tissue hemorrhage,edema,oxygenation index,and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups.The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups(P<0.05 or P<0.01).The animal mortality was significantly higher for the 40 cm group than for the other two groups(41.2%vs.17.8%and 10.0%,P<0.05).The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups.Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances,the peak overpressure,and the overpressure impulse.展开更多
基金the National Natural Science Foundation of China[62525301,62127811,62433019]the New Cornerstone Science Foundation through the XPLORER PRIZEthe financial support by the China Postdoctoral Science Foundation[GZB20240797].
文摘Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.
文摘OBJECTIVE To investigate the intervention effects of tissue-bone homeostasis manipulation(TBHM)on peripatellar biomechanical parameters and knee joint function in knee osteoarthritis(KOA)patients.METHODS Sixty patients with KOA(Kellgren-Lawrence gradeⅡ-Ⅲ)were recruited from the Acupuncture-Moxibustion Rehabilitation Department,Anhui University of Chinese Medicine between October 2024 and May 2025.Participants were randomized into a TBHM group(n=30)or a transcutaneous electrical neuromuscular stimulation(TENS)group(n=30).Using two-way repeated measures ANOVA,biomechanical indicators,including rectus femoris tension,vastus medialis tension,vastus lateralis tension,patellar ligament tension,lateral patellar displacement(LPD),medial patellar displacement(MPD),normalized patellar mobility(LPD/patellar width[PW],MPD/PW),knee flexion range of motion,and functional indicators,including KOOS subscales,time up and go test(TUGT),were compared between groups at baseline and after 6 weeks of intervention.RESULTS After intervention,all biomechanical and knee joint function indicators in the TBHM group were significantly improved(P<0.05,P<0.01),while only the vastus medialis tension,TUGT and KOOS Pain,ADL and QoL scores in the control group were significantly improved(P<0.01).The improvement amplitudes of biomechanical indicators in the TBHM group,including rectus femoris tension,vastus lateralis tension,patellar ligament tension,MPD/PW,LPD/PW and knee flexion range of motion were better than those in the control group(P<0.05,P<0.01).In the functional evaluation,the interaction effects of the TBHM group in all dimensions of the KOOS score and TUGT were statistically significant(P<0.05,P<0.01).Post-hoc simple effect analysis confirmed that there were significant differences in the above indicators between the two groups after intervention(P<0.05),and all indicators showed a significant main effect of time(P<0.01),suggesting that the intervention measures had continuous and cumulative curative effects.CONCLUSION TBHM effectively improves joint function and quality of life in KOA patients by restoring dynamic equilibrium in soft tissue tension and patellar mobility,ultimately achieving the therapeutic goal of concurrent tissue-bone management.
基金funded by the National Natural Science Foundation of China(42267024,42041006)the Youth Research Fund Project of Qinghai University,China(2023-QGY-10).
文摘Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important role in soil stabilization and fixation,as they resist soil erosion and shallow landslides in this area.However,the biomechanical properties of the roots of dominant herbs and their influencing factors in this area remain poorly understood.Therefore,we selected two dominant herbs in this area,Stipa aliena Keng and Poa crymophila Keng,and carried out a series of uniaxial tensile tests on the roots of the two herbs under different treatments.Meanwhile,the effects of root diameter,plant species,gauge length,root water content,and loading rate on the biomechanical properties of the two herbs'roots were analyzed.The results showed that root diameter was the most significant factor affecting the root biomechanical properties(P<0.010),and root tensile force displayed a positive power law relationship with root diameter,whereas root tensile strength and Young's modulus followed negative power law correlations with root diameter,and fracture strain increased linearly with root diameter.Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater than those of P.crymophila(P<0.001),which was mainly due to the higher lignin content and lignin:cellulose ratio of S.aliena roots.During uniaxial tensile process,hydrated roots exhibited elastic-plastic-brittle behavior,whereas dried roots exhibited elastic-brittle behavior.Root fracture strain of the two herbs was significantly lower under 100 mm gauge length than under 50 mm gauge length(P<0.001),and the Young's modulus was significantly greater(P<0.050).Tensile strength and fracture strain of hydrated roots of the two herbs were significantly greater than those of dried roots(P<0.050),whereas the Young's modulus was significantly lower(P<0.001).Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater under 20 mm/min loading rate than under 200 mm/min loading rate(P<0.050),whereas loading rate had no significant effect on the root biomechanical properties of P.crymophila(P>0.050).Fibrous roots of the two herbs were well developed,with relatively high tensile strengths and Young's moduli of 78.498 and 837.901 MPa for S.aliena,and 67.541 and 901.184 MPa for P.crymophila,respectively.The two herbs can stabilize soil and prevent soil erosion and can be used as pioneer species for ecological restoration in the upper reaches of the Yellow River.These results provide a theoretical basis for soil erosion and shallow landslide control in the giant landslide area of the upper reaches of the Yellow River.
基金financially supported by the National Natural Science Foundation of China(No.52125201)Beijing Natural Science Foundation(No.Z240025)and the Beijing Municipal Science and Technology(No.Z221100002722015).
文摘Flexible and wearable electronics are attracting surging attention due to their potential applications in human health monitoring and precision therapies.Safety hazards including strong magnetic field and electric leakage are big risk factors for human health.It remains challenging to develop self‐powered and wearable safety hazard sensors that could not only be able to monitor human motions but also have functions for detecting potential hazards.In this work,we fabricated a self‐powered,shapeable,and wearable magnetic triboelectric nanogenerator(MTENG)based on ferrofluid,Ecoflex,and carbonized silk fabric that possessed effective hazard prevention and biomechanical motion sensing ability.A peak open‐circuit voltage of 0.7 V and short‐circuit current of 10μA m^(−2)can be achieved when magnetic field is changed between 3.5 and 37.1 mT.As a component of triboelectric layer of the MTENG,ferrofluid can substantially extend the range of its sensing capabilities to many hazardous cues such as dangerous magnetic field.Furtherly,the developed multifunctional and self‐powered sensor can be used to monitor human activities such as drinking water and bending finger.This effort opens up a new design opportunity for hazard avoidance wearable electronics and self‐powered sensors.
基金appreciate financial support from the National Key R&D Program of China(No.2022YFA1104600)2022 Lingang Laboratory“Seeking Outstanding Youth Program”Open Project(No.LGQS-202206-04)+3 种基金Shanghai Ninth People’s Hospital–Shanghai Jiao Tong University School of Medicine–Shanghai University of Science and Technology Cross-funded Collaborative Program(No.JYJC202233)the National Natural Science Foundation of China(No.82372377)Biomaterials and Regenerative Medicine Institute Cooperative Research Project by Shanghai Jiao Tong University School of Medicine(No.2022LHBO8),Shanghai Key Laboratory of Orthopaedic Implants,Department of Orthopaedics by Shanghai Ninth People’s Hospital–Shanghai Jiao Tong University School of Medicine(No.KFKT202206),the Key R&D Program of Jiangsu Province Social Development Project(No.BE2022708)the Project of Shanghai Science and Technology Commission(No.22015820100).
文摘In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment simulation,particularly of the mechanical microenvironment,is crucial for estimating the biological effects of a tumor.However,current in vitro osteosarcoma model construction is often limited to a single mechanical signal,which fails to simulate the diversity of osteosarcoma mechanical stimuli.In this study,we utilized embedded bioprinting technology and the multiple response properties of calcium ions in soft and hard stiffness systems with osteosarcoma cell biological functions to construct an integrated gradient biomechanical signal-tailored osteosarcoma model(IGBSTOM).We achieved this by printing a fibrinogen bioink containing calcium ions and osteosarcoma tumor spheroids within an extracellular matrix composed of methacryloylated alginate,methacryloylated gelatin,thrombin,and transglutaminase,which is rich in polysaccharides and proteins and exhibits self-healing properties.Our in vitro and in vivo studies showed that the IGBSTOM enhanced tumor stemness,proliferation,and migration,and successfully reproduced the nest-like structure of tumors,providing an in vitro research platform that is more similar to the natural tumor than the existing models.This study proposes a novel IGBSTOM construction and provides a new strategy for the clinical understanding of tumor development,drug screening,and exploration of drug resistance and metastasis mechanisms.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(RS-2024-00449812,2022R1I1A3064173)the Korea government(MSIT)(No.RS-2024-00335915).
文摘Nature-inspired designs have increasingly influenced biomedical engineering by providing superior biomechanical performance and structural stability.In this study,the diabolical ironclad beetle elytra structure was applied to stent strut designs and thoroughly evaluated through various computational simulations to assess their potential to enhance the mechanical performance of WE43 magnesium alloy stents.Connected elliptical structures with a vertical-to-horizontal length ratio of 1:1.8 were incorporated in varying numbers and then compared to conventional laser-cut stents using 3-point bending,crush,crimping,and expansion tests,internal carotid artery insertion simulations,and computational fluid dynamics analyses.The results demonstrated that the biomimetic stents exhibited significantly improved stress distribution and reduced applied stress while maintaining hemodynamic stability.Computational fluid dynamics simulations further confirmed that the biomimetic could reduce wall shear stress and improve blood flow,thereby potentially minimizing the risk of restenosis and thrombosis.These findings suggest that diabolical ironclad beetle-inspired stent structures may offer enhanced biomechanical performance and clinical safety in magnesium-based endovascular interventions.
基金Supported by China Primary Health Care Foundation(No.MTP2022C025)Beijing Natural Science Foundation of China(No.7242168).
文摘AIM:To investigate the relationship between preoperative corneal biomechanical properties and corneal tomographic properties in cataract patients.METHODS:The study consisted of 59 eyes of 30 participants who were diagnosed as cataract in Peking University Third Hospital between September 2019 and November 2019.Stepwise multivariable linear regression analysis was calculated to determine the relationship between corneal biomechanical parameters and tomographic parameters.The patients were classified into three groups of with the rule(WTR)astigmatism,against the rule astigmatism and oblique astigmatism.And the differences in corneal parameters among different groups were compared.RESULTS:There were significant differences in the first applanation time(A1T),the first applanation length(A1L),corneal velocity during the first applanation(Vin),the second applanation time(A2T),highest concavity(HC)radius,displacement amount(DA),DA ratio,stiffness parameter A1(SPA1)and integrated radius(IR)between oblique astigmatism patients and the other two groups.Total corneal steep meridian(K2)was negatively associated with A1L,A1T and corneal velocity during the second applanation(Vout).Patients with higher anterior corneal curvature had lower HC radius and central corneal thickness(CCT;P=0.001 and 0.006,respectively),while the Ambrosio relational thickness to the horizontal profile(ARTh)was higher than those with lower anterior corneal curvature(P=0.009).CONCLUSION:The study reveals that the elasticity of corneal collagen fibers is greater,but the viscoelasticity of cornea is smaller in patients with oblique astigmatism.There is no significant difference in ARTh between patients with different types of astigmatism,that is,the corneal biomechanical specificity of oblique astigmatism group is probably not caused by corneal thickness.Moreover,we find patients with higher anterior corneal curvature has lower HC radius and CCT but higher ARTh than those with lower anterior corneal curvature.
基金Supported by the Special Fund for Crop Breeding of Sichuan Provincial Department of Education,China (2006LD006)the Rapeseed Breeding Research Program of Science & Technology Department of Sichuan Province,China (2006YZGG-5-5)~~
文摘[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.
文摘OBJECTIVE:To investigate the site specificity and differences of the Hegu(LI4)located on the midpoint of the second metacarpal and the point where the bases of the first and second metacarpal bones on the dorsum was historically used as Hegu(LI4)in Japan,through morphological,biomechanical,and histological analyses.METHODS:We defined distally located Hegu(LI4)as Hegu(LI4)-D and proximally located Hegu(LI4)as Hegu(LI4)-P.The distance from the skin surface to the blood vessels as well as the biomechanical properties of the two Hegu(LI4)samples were measured using an ultrasound device and Myoton PRO(Myoton AS,Tallinn,Estonia),respectively,in 20 healthy adult volunteers.Sympathetic fibers under the two Hegu(LI4)samples were histologically observed using tyrosine hydroxylase(TH)immunostaining in 10 cadavers.RESULTS:Hegu(LI4)-D was classified into type 1 with blood vessels<4 mm away from the skin surface,and type 2 with blood vessels>10 mm away from the skin surface.In Hegu(LI4)-P,blood vessels were approximately 10 mm away from the surface.Further,Hegu(LI4)-P had significantly higher tone,stiffness,and elasticity than Hegu(LI4)-D(P<0.0001).TH-positive fibers were present near the artery in Hegu(LI4)-P.CONCLUSION:Hegu(LI4)-D and Hegu(LI4)-P differed in terms of hardness and the distance between the skin surface and blood vessels.Furthermore,sympathetic nerve fibers were present near the artery in Hegu(LI4)-P.Taken together,these results suggest that there is site specificity of morphological,biomechanical,and histological differences between the Hegu(LI4)-D and Hegu(LI4)-P.
基金Supported by Noor Ophthalmology Research Center.
文摘Biomechanical study of the visual system by ocular response analyzer investigates the inter-structural biological relationships,mechanics,and function of the visual system.This review aimed to investigate the changes in corneal biomechanical parameters with age and sex.The articles published in PubMed between 2000 and 2021 were investigated and critiqued,and valid scientific evidence was collected,reviewed and concluded according to the inclusion and exclusion criteria.Most studies showed that corneal biomechanical changes occur infrequently in children up to the age of 20y,and with increasing age and wider age range,there was a significant decrease in corneal biomechanical indices,especially corneal hysteresis.In children and adults,most studies have shown that these biomechanical indicators,especially corneal resistance factor,were higher in females.Although hormonal changes may contribute to this finding,the role of axial length and other biometric indicators should not be ignored.The axial length,the intraocular pressure,and the corneal thickness are other factors associated with biomechanical parameters that should be taken into account in clinical diagnosis and management especially for patients undergoing refractive surgery as well as keratoconus patients.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272250 and 12372310)China Postdoctoral Science Foundation(Grant No.2020M680913)+1 种基金Shanxi Scholarship Council of China(Grant No.2022-081)Shanxi Postgraduate Innovation Project and Shanxi Huajin Orthopaedic Public Foundation.
文摘Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively inferior performance compared to traditional metal stents with identical structural characteristics.Therefore,improving their mechanical properties is a key issue in the development of biodegradable magnesium alloy stents.In this study,three new stent structures(i.e.,stent A,stent B,and stent C)were designed based on the typical structure of biodegradable stents.The changes made included altering the angle and arrangement of the support rings to create a support ring structure with alternating large and small angles,as well as modifying the position and shape of the link.Using finite element analysis,the compressive performance,expansion performance,bending flexibility performance,damage to blood vessels,and hemodynamic changes of the stent were used as evaluation indexes.The results of these comprehensive evaluations were utilized as the primary criteria for selecting the most suitable stent design.The results demonstrated that compared to the traditional stent,stents A,B,and C exhibited improvements in radial stiffness of 16.9%,15.1%,and 37.8%,respectively;reductions in bending stiffness of 27.3%,7.6%,and 38.1%,respectively;decreases in dog-boning rate of 5.1%,93.9%,and 31.3%,respectively;as well as declines in the low wall shear stress region by 50.1%,43.8%,and 36.2%,respectively.In comparison to traditional stents,a reduction in radial recoiling was observed for stents A and C,with decreases of 9.3% and 7.4%,respectively.Although there was a slight increase in vessel damage for stents A,B,and C compared to traditional stents,this difference was not significant to have an impact.The changes in intravascular blood flow rate were essentially the same after implantation of the four stents.A comparison of the four stents revealed that stents A and C exhibited superior overall mechanical properties and they have greater potential for clinical application.This study provides a reference for designing clinical stent structures.
基金the Applied Basic Research Program of Educational Department of Liaoning Province(No.LJKZZ20220058)。
文摘Due to the lack of human avoidance analysis,the orthosis cannot accurately apply orthopedic force during orthopedic,resulting in poor orthopedic effect.Therefore,the relationship between the human body’s active avoidance ability and force application is studied to achieve accurate loading of orthopedic force.First,a high-precision scoliosis model was established based on computed tomography data,and the relationship between orthopedic force and Cobb angle was analyzed.Then 9 subjects were selected for avoidance ability test grouped by body mass index calculation,and the avoidance function of different groups was fitted.The avoidance function corrected the application of orthopedic forces.The results show that the optimal correction force calculated by the finite element method was 60 N.The obese group had the largest avoidance ability,followed by the standard group and the lean group.When the orthopedic force was 60 N,the Cobb angle was reduced from 33.77°to 20°,the avoidance ability of the standard group at 50 N obtained from the avoidance function was 20.28%and 10.14 N was actively avoided.Therefore,when 50 N was applied,60.14 N was actually generated,which can achieve the orthopedic effect of 60 N numerical simulation analysis.The avoidance effect can take the active factors of the human body into consideration in the orthopedic process,so as to achieve a more accurate application of orthopedic force,and provide data reference for clinicians in the orthopedic process.
基金the National Natural Science Foundation of China(Nos.32260235 and 82260446)。
文摘Cage plus plate(CP)and zero-profile(Zero-P)devices are widely used in anterior cervical discectomy and fusion(ACDF).This study aimed to compare adjacent segment biomechanical changes after ACDF when using Zero-P device and CP in different segments.First,complete C1—C7 cervical segments were constructed and validated.Meanwhile,four surgery models were developed by implanting the Zero-P device or CP into C4—C5 or C5—C6 segments based on the intact model.The segmental range of motion(ROM)and maximum value of the intradiscal pressure of the surgery models were compared with those of the intact model.The implantation of CP and Zero-P devices in C4—C5 segments decreased ROM by about 91.6%and 84.3%,respectively,and increased adjacent segment ROM by about 8.3%and 6.82%,respectively.The implantation of CP and Zero-P devices in C5—C6 segments decreased ROM by about 93.3%and 89.9%,respectively,while increasing adjacent segment ROM by about 4.9%and 4%,respectively.Furthermore,the implantation of CP and Zero-P devices increased the intradiscal pressure in the adjacent segments of C4—C5 segments by about 4.5%and 6.7%,respectively.The implantation of CP and Zero-P devices significantly increased the intradiscal pressure in the adjacent segments of C5—C6 by about 54.1%and 15.4%,respectively.In conclusion,CP and Zero-P fusion systems can significantly reduce the ROM of the fusion implant segment in ACDF while increasing the ROM and intradiscal pressure of adjacent segments.Results showed that Zero-P fusion system is the best choice for C5—C6 segmental ACDF.However,further studies are needed to select the most suitable cervical fusion system for C4—C5 segmental ACDF.Therefore,this study provides biomechanical recommendations for clinical surgery.
基金Supported by Wu Jieping Medical Foundation(No.320.6750.2021-04-15).
文摘AIM:To assess the visual outcomes and corneal biomechanical properties of myopia patients between laser in situ keratomileusis(LASIK)and LASIK combined with accelerated corneal crosslinking(LASIK Xtra).METHODS:This prospective study analyzed 52 consecutive myopia patients treated with LASIK Xtra and 45 consecutive myopia patients treated with LASIK.Only the right eyes in the two groups were analyzed.The uncorrected distance visual acuity(UDVA),keratometry values,postoperative central corneal thickness(CCT),corneal demarcation line depth,the corneal compensated intraocular pressure(IOPcc),Goldmann-correlated IOP(IOPg),corneal resistance factor(CRF)and corneal hysteresis(CH)from Ocular Response Analyzer(ORA)were analyzed.Further,the correlation between the demarcation line depth and ORA-related biomechanical parameters were analyzed.RESULTS:No significant differences in UDVA,postoperative CCT,or mean K values were found between the 2 groups at 1 to 12mo postoperative follow-up(all P>0.05).The changes of CRF was significantly lower in the LASIK Xtra group compared to the LASIK group(all P<0.05)at all the postoperative visits.The changes of CH were significantly higher in the LASIK Xtra group(all P<0.05).No significant differences were discovered regarding the changes of IOPcc and IOPg posperatively(all P>0.05).Out of 52 cases in the LASIK Xtra group,the demarcation line was present in 40 eyes(77%).The average depth of the demarcation was 220.73±42.70μm(136 to 288μm).No significant correlation was observed between the depth of the demarcation line and any of the ORA-related biomechanical parameters such as IOPcc,IOPg,CRF and CH at 12mo(all P>0.05).CONCLUSION:Both procedures demonstrate comparable outcomes in terms of visual acuity,refraction and ablation predictability.This study confirms that corneal biomechanical properties of the included patients weakened after both procedures,but the cornea after LASIK Xtra are stiffer than conventional LASIK.
基金Supported by the Ministry of EconomyIndustry and Competitiveness of Spain within the program Ramón y Cajal,RYC-2016-20471。
文摘AIM: To investigate the short and long term corneal biomechanical changes after overnight orthokeratology(OK) and compare them with those occurring in subjects not wearing contact lenses.METHODS: Retrospective case control study enrolling 54 subjects that were divided into three groups 18 subjects each: control group(CG), short term(15 nights) OK(STOK) group, and long term(more than 1 y of OK wear) OK(LTOK) group. Corneal biomechanics were characterized using the Cor Vis? ST system(Oculus), recording parameters such as time [first/second applanation time(AT1, AT2)], speed [velocity of corneal apex at the first/second applanation time(AV1, AV2)], and amplitude of deformation(AD1, AD2) in the first and second corneal flattening, corneal stiffness(SPA1), biomechanically corrected intraocular pressure(b IOP) and corneal(CBI) and tomographic biomechanical indices(TBI).RESULTS: Significantly lower AD1 and standard deviate on of Ambrosio’s relational average thickness related to the horizontal profile(ARTh) values were found in the OK groups compared to CG(P<0.05). Likewise, significantly higher values of CBI were found in STOK and LTOK groups compared to CG(P<0.01). No significant differences between groups were found in integrated radius index(P=0.24), strain stress index(P=0.22), tomographic biomechanical index(P=0.91) and corneal stif fness parameter(SPA1, P=0.97). Significant inverse correlations were found between corneal thickness and CBI in STOK(r=-0.90, P<0.01) and LTOK groups(r=-0.71, P<0.01).CONCLUSION: OK does not seem to alter significantly the corneal biomechanical properties, but special care should be taken when analyzing biomechanical parameters influenced by corneal thickness such as amplitude of deformation, ARTh or CBI, because they change significantly after treatment but mainly due to the reduction and pachymetric progression induced by the corneal molding secondary to OK treatment.
文摘Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relationship with the physiological responses of the therapy.So far,however,there has not been a unified approach to standardize these biomechanical characteristics.In fact,it is still undetermined how they affect the observed clinical outcomes of spinal manipulation.This study,therefore,reviewed the current body of literature to explore these dosage parameters and evaluate their significance,with respect to physiological and clinical outcomes.From the experimental studies reviewed herein,it is evident that the modulation of manipulation’s biomechanical parameters elicits transient physiological responses,including changes in neuronal activity,electromyographic responses,spinal stiffness,muscle spindle responses,paraspinal muscle activity,vertebral displacement,and segmental and intersegmental acceleration responses.However,to date,there have been few clinical trials that tested the therapeutic relevance of these changes.In addition,there were some inherent limitations in both human and animal models due to the use of mechanical devices to apply the thrust.Future studies evaluating the effects of varying biomechanical parameters of spinal manipulation should include clinicians to deliver the therapy in order to explore the true clinical significance of the dose-response relationship.
文摘The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.
基金Supported by Shanxi Provincial Health Department of Science and Technology Research Projects (No.201201019)
文摘AIM： To compare the changes in corneal biomechanics measured by ocular response analyzer （ORA） after 2.2-ram microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS： The prospective nonrandomized study comprised eyes with cataract that had 2.2-mm coaxial microincision or 3.0 -mm standard incision phacoemulsification. The corneal hysteresis （CH）, corneal resistance factor （CRF）, corneal-compensated intraocular pressure （IOPcc） and Goldmann-correlated intraocular pressure （IOPg） were measured by ORA preoperatively and at ld, 1-, 2-, 3- and 4-week postoperatively. Results were analyzed and compared between groups. RESULTS： In both groups, CH decreased in the immediate postoperative period （P〈0.05）, returned to the preoperative level at one week （P =0.249） in the 2.2-mm group, and at two weeks in the 3.0-mm group （P --0.264）; there was no significant change in CRF values. In 2.2-mm group, mean IOPcc and IOPg increased at ld postoperatively （both ,P〈0.05）, and returned to preoperative level at one week （,0 =0.491 and P =0.923, respectively）. In 3.0-mm group, mean IOPcc and IOPg increased at ld and lwk postoperatively （P =0.005 and ,P =0.029, respectively）, and returned to preoperative level at 2wk （P =0.347 and P =0.887, respectively）. CONCLUSION： Significant differences between preoperative and postoperative corneal biomechanical values were found for CH, IOPcc and IOPg. But the recovery time courses were different between the two groups. The 2.2-mm coaxial microincision cataract surgery group seemed recovery faster compared to the 3.0-mm standard coaxial phacoemulsification group.
基金supported by the Major Project of Military Logistical Support Department[grant number AWS15J003and ALB19J001]。
文摘Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sources at distances of 40,44,and 48 cm from rats;and examine the changes in the gross anatomy of the lungs,lung wet/dry weight ratio,hemoglobin concentration,blood gas analysis,and pathology.Results Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance.The lung tissue hemorrhage,edema,oxygenation index,and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups.The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups(P<0.05 or P<0.01).The animal mortality was significantly higher for the 40 cm group than for the other two groups(41.2%vs.17.8%and 10.0%,P<0.05).The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups.Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances,the peak overpressure,and the overpressure impulse.
