The fracture surfaces of coal-rock masses formed under mining-induced stress generally exhibit complex geometries, and the fracture geometry is one of the primary factors affecting the seepage characteristics of coal-...The fracture surfaces of coal-rock masses formed under mining-induced stress generally exhibit complex geometries, and the fracture geometry is one of the primary factors affecting the seepage characteristics of coal-rock penetrating fracture. This paper investigates the seepage characteristics of 5 groups of coal penetrating fracture(CPF) with different joint roughness coefficients(JRCs). Based on 3D morphology scanner tests and hydraulic coupling tests, a characterization method of effective geometric parameters in fracture surfaces under various confining pressures was improved, and a relationship between effective geometric parameters and the confining pressure is established. The results indicate that the nonlinear flow behavior in a CPF primarily includes three types: non-Newtonian fluid seepage under high confining pressure and low JRC, non-Darcy seepage under low confining pressure and high JRC, and the whole process of seepage characteristics between these two conditions. Among them, nonNewtonian fluid seepage is caused by significant fracture expansion, while non-Darcy seepage can be attributed to turbulence effects. During the seepage process, the geometric parameters with different JRC fracture samples all exhibit exponential changes with the increase of confining pressure. In addition,under high confining pressure, the effective contact ratio, effective fracture aperture, and void deviation ratio with high JRC fracture samples under high confining pressure increase by 93.5%, 67.4%, and 24.9%,respectively, compared with those of low JRC fracture samples. According to the variation of geometric parameters in a CPF with external stress, a seepage model considering geometric parameters in a CPF is proposed. By introducing the root mean square error(RMSE) and coefficient of determination(R2) to evaluate the error and goodness of fit between model curves and experimental data, it is found that the theoretical curves of model in this paper have the best matching with the experimental data. The average values of RMSE and R2for model in this paper are 0.002 and 0.70, respectively, which are better than models in the existing literature.展开更多
Shrapnel projectiles from low-velocity weapons often cause perforations and thereby result in multiple wounds. As shrapnel penetrates, its kinetic energy dissipates and generates forces that influence the extent of da...Shrapnel projectiles from low-velocity weapons often cause perforations and thereby result in multiple wounds. As shrapnel penetrates, its kinetic energy dissipates and generates forces that influence the extent of damage. However, quantifying these forces and understanding the mechanics of tissue damage remain challenging. To address this, there is a need to measure time-varying forces that will provide critical insights into the mechanics of damage initiation and progression. In this study, a new experimental methodology was developed using a custom-designed fixture integrated with a low-velocity gas gun to study shrapnel-induced damage in ballistic gelatin. The fixture was equipped with piezoelectric sensors to capture transmitted force(TF), while a high-speed camera recorded the damage morphology. The maximum TF response varied significantly, ranging from 45 to 225 N for chisel-nose shrapnel and 75–295 N for blunt-nose shrapnel, across incident velocities of 25–100 m/s. The damage mechanisms, characterized by the formation of temporary cavities, resulted in cavity sizes three to four times larger than the shrapnel diameter. The maximum energy absorbed by the ballistic gelatin was 14.81 J at 92.10 m/s for chisel-nose and 18.50 J at 98.35 m/s for blunt-nose shrapnel. A finite element(FE) model was developed and validated against experimental results with an error margin of less than 15% in the maximum value of TF. This methodology provides a platform for further studies on soft tissue damage by correlating dynamic force measurements with damage mechanisms. These insights can inform advancements in battlefield injury assessment, medical interventions strategies, and the design of protective materials to mitigate shrapnel injuries.展开更多
Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions an...Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions and exospheric neutrals serve as an important diagnostic for ion-neutral interactions and upper atmospheric loss.This study presents direct observations of hydrogen ENAs(H-ENAs)on the dayside of Mars by using the Mars Ion and Neutral Particle Analyzer(MINPA)onboard China’s Tianwen-1 orbiter.By analyzing H-ENA data during a coronal mass ejection and a stream interaction region from December 29,2021,to January 1,2022,and comparing these data with MAVEN/SWIA(Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer)solar wind measurements,we examine the temporal evolution of H-ENA flux and the associated sputtered escape of atmospheric constituents.The observed H-ENA velocity is consistent with upstream solar wind ions,and the H-ENA-to-ion intensity ratio is used to infer variations in exospheric density,revealing a delayed response to enhanced solar wind activity.Penetrating H-ENA intensities reach up to 5.3×10^(6)s^(−1) cm^(−2),with energy fluxes on the order of(0.5-8.1)×10^(−3) mW/m^(2).The estimated oxygen sputtered escape rate driven by penetrating H-ENAs ranges from 5.5×10^(23)s^(−1) to 5.2×10^(24)s^(−1),comparable to or exceeding previous estimates based on penetrating ions.The findings highlight the need for low-altitude H-ENA observations to better quantify their atmospheric interactions and refine our understanding of nonthermal escape processes at Mars.展开更多
Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect pene...Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect penetration abilities of nanostructured lipid carriers（NLC）. Real--time penetration of folate--or cell penetrating peptide（CPP）-modified NLC was evaluated using a multicellular tumor spheroid（MTS） established by stacking culture method as an in vitro testing platform. The results suggested that CPP modification had a better penetration behavior both on penetration depth and intensity compared with folate-modified NLC at the early stage of penetration process.展开更多
Given its ability to knock down essentially any gene of interest, siRNA has been one of the promising candidates for gene therapy. However, like other nucleic-acid-based drugs, its poor cellular uptake poses a major c...Given its ability to knock down essentially any gene of interest, siRNA has been one of the promising candidates for gene therapy. However, like other nucleic-acid-based drugs, its poor cellular uptake poses a major challenge. Here we briefly summarize the use of cell penetrating peptides （CPPs） as a novel and promising approach for siRNA delivery. The main advantages of CPPs are their low toxicity and high efficiency.展开更多
Objective: To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus. Methods: Seventy-five eyes of 64 patients who received fu...Objective: To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus. Methods: Seventy-five eyes of 64 patients who received full-bed DALK and 52 eyes of 51 patients who received PK between June 2000 and August 2010 were included in this retrospective study. Full-bed DALK was performed using Yao's hooking-detaching technique. PK was performed using a standard technique. Intraoperative and postoperative complications, visual acuity, rejection, graft survival, endothelial cell density, corneal sensation recovery, and re-innervation were compared between the two groups. Results: A best correct visual acuity of 0.5 or better was achieved in 90.7% of eyes after full-bed DALK and in 92.3% of eyes after PK (P=0.75). By the fifth postoperative year, graft endothelial cell loss reached 34.6% in the PK group vs. 13.9% in the full-bed DALK group (P<0.001). There were no statistical differences in corneal sensitivity recovery or corneal re-innervation between the groups (P>0.05). Intraoperative microperforation occurred in seven out of 75 (9.3%) eyes with a temporally postoperative double anterior chamber in two eyes in the full-bed DALK group. Postoperative complications in the PK vs. the full-bed DALK groups respectively were: rejection (7.7% vs. 0%, P=0.015), high intraocular pressure (IOP) (46.2% vs. 1.3%, P<0.001), secondary glaucoma (9.6% vs. 0%, P=0.006), complicated cataract (19.2% vs. 0%, P<0.001), and wound dehiscence (9.6% vs. 0%, P=0.006). Conclusions: Both full-bed DALK and PK can offer long-term satisfactory visual outcomes for keratoconus. Graft rejection, secondary glaucoma, complicated cataracts, and constant endothelial cell loss were observed in eyes only after PK.展开更多
OBJECTIVE: To observe the clinical effect of pricking and penetrating moxibustion therapy on refractory insomnia.METHODS: Totally 60 subjects were randomly divided into treatment group and control group, 30 in each gr...OBJECTIVE: To observe the clinical effect of pricking and penetrating moxibustion therapy on refractory insomnia.METHODS: Totally 60 subjects were randomly divided into treatment group and control group, 30 in each group. The treatment group was treated with pricking and penetrating moxibustion therapy, the control group with penetrating moxibustion therapy, the treatment was given once every day, two groups of patients were treated 20 times,compared the efficacy, pinsburgh sleep quality index(PSQI) and Traditional Chinese Medicine symptom, safety evaluation between the two groups.RESULTS: Compared with 10, 20 times after the treatment, the effective rate of the treatment group(93.3%) higher than that of the control group(80.0%)(P < 0.05); Compared with beforetreatment, 20 times after treatment, the PSQI and TCM symptom pattern scores of the two groups were significantly decreased(P < 0.01); Compared with 10, 20 times after the treatment, the treatment group are better than the control group in improving the total score and the integral of PSQI(P <0.05 or P < 0.01); The treatment group are better than the control group in improving the TCM symptom pattern score, difficulty in going to sleep, palpitation, amnesia, fidget, sweating, impaired concentration(P < 0.01 or P < 0.05).CONCLUSION: The pricking and penetrating moxibustion therapy is safe and effective in the treatment of refractory insomnia and the treatment can improve the curative effect of the therapy that uses penetrating moxibustion only.展开更多
AIM: To evaluate the effect of corneal graft diameter on therapeutic penetrating keratoplasty(PKP) for fungal keratitis. METHODS: A total of 116 patients (116 eyes) suffered from fungal keratitis underwent PKP at the ...AIM: To evaluate the effect of corneal graft diameter on therapeutic penetrating keratoplasty(PKP) for fungal keratitis. METHODS: A total of 116 patients (116 eyes) suffered from fungal keratitis underwent PKP at the Affiliated Hospital of Medical College Qingdao University from May 2006 to May 2010. They were divided into two groups according to the corneal graft diameter. 64 eyes' corneal graft diameter was 8.00mm or larger and 52 eyes' graft diameter was smaller than 8.00mm. The follow-up time was 2 years. The postoperative visual acuity and complications were documented and compared. RESULTS: Sixty-two (96.88%) eyes and fifty (96.15%) eyes preserved eyeballs respectively in two groups. There was no statistical difference in postoperative visual acuity (P = 0.961), corneal graft dear rate (P=0.132) or the incidence of recurred fungal infection (P=0.770) between two groups. But there was a higher incidence of graft rejection (P=0.020) and secondary glaucoma (P=0.039) in group with corneal graft diameter 8.00mm or larger. CONCLUSION: PKP is an effective treatment approach for fungal keratitis. There is a higher incidence of complications in large-diameter PKP for fungal keratitis.Effective, preventive and therapeutic measures can improve the prognosis.展开更多
Mucus can effectively protect the exposed mucosal surfaces due to its adhesive and viscoelastic properties.Most foreign particulates are efficiently trapped in mucus layers via steric obstruction and adhesion.Trapped ...Mucus can effectively protect the exposed mucosal surfaces due to its adhesive and viscoelastic properties.Most foreign particulates are efficiently trapped in mucus layers via steric obstruction and adhesion.Trapped particles are typically removed from the mucosal tissue within seconds to a few hours depending on their location sites.This article focuses on describing the tenacious mucus barrier properties,the strategies to investigate the interaction of nanoparticles with the mucus as well as the novel developments of mucus penetrating nanoparticles.展开更多
The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various ...The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various mechanisms,provide feasible solutions for efficient delivery of biologically active agents to circumvent biological barriers.After years of development,the function of CPPs is beyond cell penetrating.Multifunctional CPPs with bioactivity or active targeting capacity have been designed and successfully utilized in delivery of various cargoes against tumor,myocardial ischemia,ocular posterior segment disorders,etc.In this review,we summarize recent progress in CPP-functionalized nano-drug delivery systems to overcome the physiological and pathological barriers for the applications in cardiology,ophtalmology,mucus,neurology and cancer,etc.We also highlight the prospect of clinical translation of CPP-functionalized drug delivery systems in these areas.展开更多
Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper ...Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper to decompose and extract feature of the echo signal. Then, the extracted feature vector is fed up to a feed forward muhi layer perceptron classifier. Experimental results based on the measured GPR, echo signals obtained from the Mei shan railway are presented.展开更多
Tilt probe penetrating friction stir welding(PFSW)was an innovative technology proposed in recent years to avoid the formation of kissing bond in the root of joint.However,with the heat input decreasing,"S"l...Tilt probe penetrating friction stir welding(PFSW)was an innovative technology proposed in recent years to avoid the formation of kissing bond in the root of joint.However,with the heat input decreasing,"S"line or zigzag line was easily introduced in the PFSW joint.In this study,ultrasonic enhanced tilt probe penetrating friction stir welding(U-PFSW)was developed to solve this problem and achieve improved joint mechanical properties.The experimental results confirmed that U-PFSW was a potent technology to completely clear the original butt surface,providing a crucial prerequisite for the achievement of highstrength joint.The application of ultrasonic improves the joint tensile strength and fracture elongation from 336 MPa and 4.3%to 359 MPa and 6.8%,respectively.Furthermore,the strength of stir zone was also increased from 391 MPa in PFSW to 420 MPa in U-PFSW.Analyses of texture and precipitate indicated that the dynamic recrystallization(DRX)and precipitation strengthening were both enhanced by the ultrasonic.Ultrasonic-enhanced DRX enabled a complete elimination of the"S"line;the enhanced precipitation strengthening by vacancy-induced mechanism in U-PFSW was the intrinsic reason for the significantly improved mechanical properties.展开更多
The conventional method which assumes the soil distribution is continuous was unsuitable for estimating soil organic carbon density(SOCD) in Karst areas because of its discontinuous soil distribution. The accurate est...The conventional method which assumes the soil distribution is continuous was unsuitable for estimating soil organic carbon density(SOCD) in Karst areas because of its discontinuous soil distribution. The accurate estimation of SOCD in Karst areas is essential for carbon sequestration assessment in China. In this study, a modified method,which considers the vertical proportion of soil area in the profile when calculating the SOCD, was developed to estimate the SOCD in a typical Karst peak-cluster depression area in southwest China. In the modified method, ground-penetrating radar(GPR) technology was used to detect the distribution and thickness of soil. The accuracy of the method was confirmed through comparison with the data obtained using a validation method, in which the soil thickness was measured by excavation. In comparison with the conventional method and average-soil-depth method,the SOCD estimated using the GPR method showed the minimum relative error with respect to that obtained using the validation method. At a regional scale, the average SOCDs at depths of 0-20 cm and 0-100 cm, which were interpolated by ordinary kriging,were 1.49(ranging from 0.03-5.65) and 2.26(0.09-11.60) kgm-2based on GPR method in our study area(covering 393.6 hm2), respectively. Therefore, the modified method can be applied on the accurate estimation of SOCD in discontinuous soil areas such as Karst regions.展开更多
As the amount of data produced by ground penetrating radar （GPR） for roots is large, the transmission and the storage of data consumes great resources. To alleviate this problem, we propose here a root imaging algor...As the amount of data produced by ground penetrating radar （GPR） for roots is large, the transmission and the storage of data consumes great resources. To alleviate this problem, we propose here a root imaging algorithm using chaotic particle swarm optimal （CPSO） compressed sensing based on GPR data according to the sparsity of root space. Radar data are decomposed, observed, measured and represented in sparse manner, so roots image can be reconstructed with limited data. Firstly, radar signal measurement and sparse representation are implemented, and the solution space is established by wavelet basis and Gauss random matrix; secondly, the matching function is considered as the fitness function, and the best fitness value is found by a PSO algorithm; then, a chaotic search was used to obtain the global optimal operator; finally, the root image is reconstructed by the optimal operators. A-scan data, B-scan data, and complex data from American GSSI GPR is used, respectively, in the experimental test. For B-scan data, the computation time was reduced 60 % and PSNR was improved 5.539 dB; for actual root data imaging, the reconstruction PSNR was 26.300 dB, and total computation time was only 67.210 s. The CPSO-OMP algorithm overcomes the problem of local optimum trapping and comprehensively enhances the precision during reconstruction.展开更多
Objectives:To observe the clinical effect on the sequela of peripheral facial paralysis treated with the penetrating-sticking-pulling technique of acupuncture.Methods:A total of 53 patients with the sequela of periphe...Objectives:To observe the clinical effect on the sequela of peripheral facial paralysis treated with the penetrating-sticking-pulling technique of acupuncture.Methods:A total of 53 patients with the sequela of peripheral facial paralysis were diagnosed and divided into an observation group(26 cases)and a control group(27 cases)according to the visiting sequence.In the observation group,the penetrating-sticking-pulling technique of acupuncture was adopted.The Sibai(四白ST 2),Quanliao(颧髎 SI 18)and Jiache(颊车ST 6)et al.were needling toward Dicang(地仓ST 4)separately.The combined acupoints were selected according to clinical symptoms of individual patient.In the control group,the routine acupuncture was used,in which,ST 2,EX-HN 5,ST 7,ST 6,and ST 4 as well as Hegu(合谷LI 4)on the healthy side were selected.The treatment was given once every two days and a 7-treatment made one course.There were 3 days at interval between the courses.After 2 courses of treatment,the facial nerve function,e.g.,Hourse-Brackmann(H-B)grading,Sunnybrook score and clinical effect were observed.Results:①After treatment,H-B grading and Sunnybrook score were better than those before treatment in either of the observation group or the control group(P<0.05,P<0.01).H-B grading and Sunnybrook score were(2.23±0.64)and(96.62±2.59),respectively,in the observation group after treatment and they were(3.21±0.43)and(80.33±3.16)respectively in the control group.H-B grading and Sunnybrook score in the observation group were better than the control group,indicating the significant differences(P<0.05,P<0.01).②The curative rate and the total effective rate were 69.23%and 96.15%,respectively,in the observation group and they were 37.04%and 81.48%,respectively,in the control group,presenting the significant differences(both P<0.05).Conclusion:The penetrating-sticking-pulling technique of acupuncture achieves the definite effect on the sequela of peripheral facial paralysis and this therapy deserves to be promoted in clinical practice.展开更多
The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the ...The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.展开更多
Twenty samples of endothelia removed from normal and post penetrating keratoplas-ty (0.5,1,2,3 months after penetrating keratoplasty) were observed by scanning electron mi-croscopy.The photographs of the endothelia in...Twenty samples of endothelia removed from normal and post penetrating keratoplas-ty (0.5,1,2,3 months after penetrating keratoplasty) were observed by scanning electron mi-croscopy.The photographs of the endothelia in graft-host junction were analyzed by computer-assisted image analysis system,and the morphometric indexes examined were area of the cells,perimeters,density,figure coefficient,long axis,coefficient of variation of the area,and oth-ers.Results showed that the morphology and the density of the endothelial cells changed obvi-ously after operation and improved slowly but progressively with time although at 3 monthspostoperatively some differences still existed.By using the new techniques,the experiment con-firmed and enriched the theories on the corneal endothelial wound-healing,revealing some ofthe new characters of the endothelial wound-healing following penetrating keratoplasty.展开更多
AIM: To identify the current indications and the trend shifts for penetrating keraboplasty (PKP) in Shandong. METHODS: The medical charts of all patients who underwent PKP at Shandong Eye Institute from June 1, 2005 t...AIM: To identify the current indications and the trend shifts for penetrating keraboplasty (PKP) in Shandong. METHODS: The medical charts of all patients who underwent PKP at Shandong Eye Institute from June 1, 2005 to May 31, 2010 were analysed retrospectively. RESULTS: A total of 875 patients (875 eyes) received PKP in this 5-year period, accounting for 61.6% of all corneal transplantation surgeries. The leading indications for PKP were infectious keratitis (37.1%), HSK (19.1%), keratoconus (11.2%), bullous keratopathy (8.5%), regrafting (6.7%) and corneal scarring (4.8%). The percentage of PKP for keratoconus declined year by year, whereas the percentage of bullous keratopathy had a mild annual increase. Fungal infections accounted for 65.2% of the infectious keratitis cases, remaining the leading cause of corneal infection. In addition, 54.1% of bullous keratopathy cases were associated with cataract surgery. The leading initial diagnoses associated with regrafting were infectious keratitis (38.9%), HSK (18.6%) and corneal burn (16.9%). The major causes of regrafting included graft endothelial dysfunction (39.0%), graft ulcer (28.8%) and primary disease recurrence (15.3%). CONCLUSION: Infectious keratitis remained the leading indication for PKP in Shandong, and fungal infections were still the major cause of corneal infections. There was an increasing trend in the percentage of PKP cases indicated for bullous keratopathy but a decline in the same for keratoconus. Even with a decline in the overall proportion among all corneal transplantation surgeries, PKP is still the major corneal transplant choice in Shandong.展开更多
The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of c...The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of curl interface underground or “v” figure complex model, it is difficult to realize. So it is important to forward the complex geoelectricity model. This paper takes two Maxwell’s vorticity equations as departure point, makes use of the principles of Yee’s space grid model theory and the basic principle finite difference time domain method, and deduces a GPR forward system of equation of two dimensional spaces. The Mur super absorbed boundary condition is adopted to solve the super strong reflection on the interceptive boundary when there is the forward simulation. And a self-made program is used to process forward simulation to two typical geoelectricity model.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 52474161, and 52404093)Fundamental Research Program of Shanxi Province (Nos. 202303021222168 and 202203021221143)+1 种基金Taiyuan University of Science and Technology Scientific Research Initial Funding (No. 20242103)the Postdoctoral Research Foundation of China(No. 2023M733778)。
文摘The fracture surfaces of coal-rock masses formed under mining-induced stress generally exhibit complex geometries, and the fracture geometry is one of the primary factors affecting the seepage characteristics of coal-rock penetrating fracture. This paper investigates the seepage characteristics of 5 groups of coal penetrating fracture(CPF) with different joint roughness coefficients(JRCs). Based on 3D morphology scanner tests and hydraulic coupling tests, a characterization method of effective geometric parameters in fracture surfaces under various confining pressures was improved, and a relationship between effective geometric parameters and the confining pressure is established. The results indicate that the nonlinear flow behavior in a CPF primarily includes three types: non-Newtonian fluid seepage under high confining pressure and low JRC, non-Darcy seepage under low confining pressure and high JRC, and the whole process of seepage characteristics between these two conditions. Among them, nonNewtonian fluid seepage is caused by significant fracture expansion, while non-Darcy seepage can be attributed to turbulence effects. During the seepage process, the geometric parameters with different JRC fracture samples all exhibit exponential changes with the increase of confining pressure. In addition,under high confining pressure, the effective contact ratio, effective fracture aperture, and void deviation ratio with high JRC fracture samples under high confining pressure increase by 93.5%, 67.4%, and 24.9%,respectively, compared with those of low JRC fracture samples. According to the variation of geometric parameters in a CPF with external stress, a seepage model considering geometric parameters in a CPF is proposed. By introducing the root mean square error(RMSE) and coefficient of determination(R2) to evaluate the error and goodness of fit between model curves and experimental data, it is found that the theoretical curves of model in this paper have the best matching with the experimental data. The average values of RMSE and R2for model in this paper are 0.002 and 0.70, respectively, which are better than models in the existing literature.
基金financial support from DRDO Industry Academia Centre of Excellence IIT Delhi (Grant No.DFTM/ 03/3203/M/01/JATC)。
文摘Shrapnel projectiles from low-velocity weapons often cause perforations and thereby result in multiple wounds. As shrapnel penetrates, its kinetic energy dissipates and generates forces that influence the extent of damage. However, quantifying these forces and understanding the mechanics of tissue damage remain challenging. To address this, there is a need to measure time-varying forces that will provide critical insights into the mechanics of damage initiation and progression. In this study, a new experimental methodology was developed using a custom-designed fixture integrated with a low-velocity gas gun to study shrapnel-induced damage in ballistic gelatin. The fixture was equipped with piezoelectric sensors to capture transmitted force(TF), while a high-speed camera recorded the damage morphology. The maximum TF response varied significantly, ranging from 45 to 225 N for chisel-nose shrapnel and 75–295 N for blunt-nose shrapnel, across incident velocities of 25–100 m/s. The damage mechanisms, characterized by the formation of temporary cavities, resulted in cavity sizes three to four times larger than the shrapnel diameter. The maximum energy absorbed by the ballistic gelatin was 14.81 J at 92.10 m/s for chisel-nose and 18.50 J at 98.35 m/s for blunt-nose shrapnel. A finite element(FE) model was developed and validated against experimental results with an error margin of less than 15% in the maximum value of TF. This methodology provides a platform for further studies on soft tissue damage by correlating dynamic force measurements with damage mechanisms. These insights can inform advancements in battlefield injury assessment, medical interventions strategies, and the design of protective materials to mitigate shrapnel injuries.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42188101, 42274211, 41974170, 42374184, 42122032, and 41974196)the Chinese Academy of Sciences (Grant Nos. QYZDJSSW-JSC028, XDA15052500, XDA17010301, and XDB41000000)+3 种基金the CNSA (Grant No. D050103)the Specialized Research Fund for State Key Laboratories of Chinathe Specialized Research Fund for Laboratory of Geospace Environment of the University of Science and Technology of Chinasupported by the International Space Science Institute (ISSI) in Bern and Beijing through the ISSI/ISSI-BJ International Team Project titled “Understanding the Mars Space Environment Through Multi-Spacecraft Measurements” (ISSI Team Project No. 23-582 and ISSI-BJ Team Project No. 58)
文摘Atmospheric escape plays a critical role in shaping the long-term climate evolution of Mars.Among the various escape mechanisms,energetic neutral atoms(ENAs)generated through charge exchange between solar wind ions and exospheric neutrals serve as an important diagnostic for ion-neutral interactions and upper atmospheric loss.This study presents direct observations of hydrogen ENAs(H-ENAs)on the dayside of Mars by using the Mars Ion and Neutral Particle Analyzer(MINPA)onboard China’s Tianwen-1 orbiter.By analyzing H-ENA data during a coronal mass ejection and a stream interaction region from December 29,2021,to January 1,2022,and comparing these data with MAVEN/SWIA(Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer)solar wind measurements,we examine the temporal evolution of H-ENA flux and the associated sputtered escape of atmospheric constituents.The observed H-ENA velocity is consistent with upstream solar wind ions,and the H-ENA-to-ion intensity ratio is used to infer variations in exospheric density,revealing a delayed response to enhanced solar wind activity.Penetrating H-ENA intensities reach up to 5.3×10^(6)s^(−1) cm^(−2),with energy fluxes on the order of(0.5-8.1)×10^(−3) mW/m^(2).The estimated oxygen sputtered escape rate driven by penetrating H-ENAs ranges from 5.5×10^(23)s^(−1) to 5.2×10^(24)s^(−1),comparable to or exceeding previous estimates based on penetrating ions.The findings highlight the need for low-altitude H-ENA observations to better quantify their atmospheric interactions and refine our understanding of nonthermal escape processes at Mars.
基金National key Basic Research Program(Grant No.2013CB932501)National Natural Science Foundation of China(Grant No.81273454 and 81473156)+1 种基金Beijing National Science Foundation(Grant No.7132113)Doctoral Foundation of the Ministry of Education(Grant No.20130001110055)
文摘Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect penetration abilities of nanostructured lipid carriers（NLC）. Real--time penetration of folate--or cell penetrating peptide（CPP）-modified NLC was evaluated using a multicellular tumor spheroid（MTS） established by stacking culture method as an in vitro testing platform. The results suggested that CPP modification had a better penetration behavior both on penetration depth and intensity compared with folate-modified NLC at the early stage of penetration process.
文摘Given its ability to knock down essentially any gene of interest, siRNA has been one of the promising candidates for gene therapy. However, like other nucleic-acid-based drugs, its poor cellular uptake poses a major challenge. Here we briefly summarize the use of cell penetrating peptides （CPPs） as a novel and promising approach for siRNA delivery. The main advantages of CPPs are their low toxicity and high efficiency.
基金Project (No. 2011C13029-2) supported by the Major Program for Science and Technology Research of Zhejiang Province, China
文摘Objective: To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus. Methods: Seventy-five eyes of 64 patients who received full-bed DALK and 52 eyes of 51 patients who received PK between June 2000 and August 2010 were included in this retrospective study. Full-bed DALK was performed using Yao's hooking-detaching technique. PK was performed using a standard technique. Intraoperative and postoperative complications, visual acuity, rejection, graft survival, endothelial cell density, corneal sensation recovery, and re-innervation were compared between the two groups. Results: A best correct visual acuity of 0.5 or better was achieved in 90.7% of eyes after full-bed DALK and in 92.3% of eyes after PK (P=0.75). By the fifth postoperative year, graft endothelial cell loss reached 34.6% in the PK group vs. 13.9% in the full-bed DALK group (P<0.001). There were no statistical differences in corneal sensitivity recovery or corneal re-innervation between the groups (P>0.05). Intraoperative microperforation occurred in seven out of 75 (9.3%) eyes with a temporally postoperative double anterior chamber in two eyes in the full-bed DALK group. Postoperative complications in the PK vs. the full-bed DALK groups respectively were: rejection (7.7% vs. 0%, P=0.015), high intraocular pressure (IOP) (46.2% vs. 1.3%, P<0.001), secondary glaucoma (9.6% vs. 0%, P=0.006), complicated cataract (19.2% vs. 0%, P<0.001), and wound dehiscence (9.6% vs. 0%, P=0.006). Conclusions: Both full-bed DALK and PK can offer long-term satisfactory visual outcomes for keratoconus. Graft rejection, secondary glaucoma, complicated cataracts, and constant endothelial cell loss were observed in eyes only after PK.
基金Supported by Project funded by China Postdoctoral Science Foundation:The mechanism of moxibustion improves rheumatoid arthritis by promoting lymphatic drainage function(No.2016M590681)
文摘OBJECTIVE: To observe the clinical effect of pricking and penetrating moxibustion therapy on refractory insomnia.METHODS: Totally 60 subjects were randomly divided into treatment group and control group, 30 in each group. The treatment group was treated with pricking and penetrating moxibustion therapy, the control group with penetrating moxibustion therapy, the treatment was given once every day, two groups of patients were treated 20 times,compared the efficacy, pinsburgh sleep quality index(PSQI) and Traditional Chinese Medicine symptom, safety evaluation between the two groups.RESULTS: Compared with 10, 20 times after the treatment, the effective rate of the treatment group(93.3%) higher than that of the control group(80.0%)(P < 0.05); Compared with beforetreatment, 20 times after treatment, the PSQI and TCM symptom pattern scores of the two groups were significantly decreased(P < 0.01); Compared with 10, 20 times after the treatment, the treatment group are better than the control group in improving the total score and the integral of PSQI(P <0.05 or P < 0.01); The treatment group are better than the control group in improving the TCM symptom pattern score, difficulty in going to sleep, palpitation, amnesia, fidget, sweating, impaired concentration(P < 0.01 or P < 0.05).CONCLUSION: The pricking and penetrating moxibustion therapy is safe and effective in the treatment of refractory insomnia and the treatment can improve the curative effect of the therapy that uses penetrating moxibustion only.
基金National Natural Science Foundation of China (No.81170825)
文摘AIM: To evaluate the effect of corneal graft diameter on therapeutic penetrating keratoplasty(PKP) for fungal keratitis. METHODS: A total of 116 patients (116 eyes) suffered from fungal keratitis underwent PKP at the Affiliated Hospital of Medical College Qingdao University from May 2006 to May 2010. They were divided into two groups according to the corneal graft diameter. 64 eyes' corneal graft diameter was 8.00mm or larger and 52 eyes' graft diameter was smaller than 8.00mm. The follow-up time was 2 years. The postoperative visual acuity and complications were documented and compared. RESULTS: Sixty-two (96.88%) eyes and fifty (96.15%) eyes preserved eyeballs respectively in two groups. There was no statistical difference in postoperative visual acuity (P = 0.961), corneal graft dear rate (P=0.132) or the incidence of recurred fungal infection (P=0.770) between two groups. But there was a higher incidence of graft rejection (P=0.020) and secondary glaucoma (P=0.039) in group with corneal graft diameter 8.00mm or larger. CONCLUSION: PKP is an effective treatment approach for fungal keratitis. There is a higher incidence of complications in large-diameter PKP for fungal keratitis.Effective, preventive and therapeutic measures can improve the prognosis.
基金support from the National Natural Science Foundation of China(81173010).
文摘Mucus can effectively protect the exposed mucosal surfaces due to its adhesive and viscoelastic properties.Most foreign particulates are efficiently trapped in mucus layers via steric obstruction and adhesion.Trapped particles are typically removed from the mucosal tissue within seconds to a few hours depending on their location sites.This article focuses on describing the tenacious mucus barrier properties,the strategies to investigate the interaction of nanoparticles with the mucus as well as the novel developments of mucus penetrating nanoparticles.
基金the financial support of the National Natural Science Foundation (82173771)Fundamental Research Funds for the Central Universities and 111 project (B18035)
文摘The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various mechanisms,provide feasible solutions for efficient delivery of biologically active agents to circumvent biological barriers.After years of development,the function of CPPs is beyond cell penetrating.Multifunctional CPPs with bioactivity or active targeting capacity have been designed and successfully utilized in delivery of various cargoes against tumor,myocardial ischemia,ocular posterior segment disorders,etc.In this review,we summarize recent progress in CPP-functionalized nano-drug delivery systems to overcome the physiological and pathological barriers for the applications in cardiology,ophtalmology,mucus,neurology and cancer,etc.We also highlight the prospect of clinical translation of CPP-functionalized drug delivery systems in these areas.
基金Supported by the National Natural Science Founda-tion of China (49984001)
文摘Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper to decompose and extract feature of the echo signal. Then, the extracted feature vector is fed up to a feed forward muhi layer perceptron classifier. Experimental results based on the measured GPR, echo signals obtained from the Mei shan railway are presented.
基金the financial supports provided by the National Natural Science Foundation of China(No.52075122 and No.51775143)Key Research and Development Program of Guangdong Province(No.2019B090921003)+1 种基金China Postdoctoral Science Foundation(No.2020M683046)Defense Industrial Technology Development Program of China(No.JCKY2017203B066)。
文摘Tilt probe penetrating friction stir welding(PFSW)was an innovative technology proposed in recent years to avoid the formation of kissing bond in the root of joint.However,with the heat input decreasing,"S"line or zigzag line was easily introduced in the PFSW joint.In this study,ultrasonic enhanced tilt probe penetrating friction stir welding(U-PFSW)was developed to solve this problem and achieve improved joint mechanical properties.The experimental results confirmed that U-PFSW was a potent technology to completely clear the original butt surface,providing a crucial prerequisite for the achievement of highstrength joint.The application of ultrasonic improves the joint tensile strength and fracture elongation from 336 MPa and 4.3%to 359 MPa and 6.8%,respectively.Furthermore,the strength of stir zone was also increased from 391 MPa in PFSW to 420 MPa in U-PFSW.Analyses of texture and precipitate indicated that the dynamic recrystallization(DRX)and precipitation strengthening were both enhanced by the ultrasonic.Ultrasonic-enhanced DRX enabled a complete elimination of the"S"line;the enhanced precipitation strengthening by vacancy-induced mechanism in U-PFSW was the intrinsic reason for the significantly improved mechanical properties.
基金supported by National Science and Technology Support Project (Grant No. 2012BAD05B03–6)Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05070403)National Natural Science Foundationof China (Grant No. 41171246)
文摘The conventional method which assumes the soil distribution is continuous was unsuitable for estimating soil organic carbon density(SOCD) in Karst areas because of its discontinuous soil distribution. The accurate estimation of SOCD in Karst areas is essential for carbon sequestration assessment in China. In this study, a modified method,which considers the vertical proportion of soil area in the profile when calculating the SOCD, was developed to estimate the SOCD in a typical Karst peak-cluster depression area in southwest China. In the modified method, ground-penetrating radar(GPR) technology was used to detect the distribution and thickness of soil. The accuracy of the method was confirmed through comparison with the data obtained using a validation method, in which the soil thickness was measured by excavation. In comparison with the conventional method and average-soil-depth method,the SOCD estimated using the GPR method showed the minimum relative error with respect to that obtained using the validation method. At a regional scale, the average SOCDs at depths of 0-20 cm and 0-100 cm, which were interpolated by ordinary kriging,were 1.49(ranging from 0.03-5.65) and 2.26(0.09-11.60) kgm-2based on GPR method in our study area(covering 393.6 hm2), respectively. Therefore, the modified method can be applied on the accurate estimation of SOCD in discontinuous soil areas such as Karst regions.
基金supported by the Fundamental Research Funds for the Central Universities(DL13BB21)the Natural Science Foundation of Heilongjiang Province(C2015054)+1 种基金Heilongjiang Province Technology Foundation for Selected Osverseas ChineseNatural Science Foundation of Heilongjiang Province(F2015036)
文摘As the amount of data produced by ground penetrating radar （GPR） for roots is large, the transmission and the storage of data consumes great resources. To alleviate this problem, we propose here a root imaging algorithm using chaotic particle swarm optimal （CPSO） compressed sensing based on GPR data according to the sparsity of root space. Radar data are decomposed, observed, measured and represented in sparse manner, so roots image can be reconstructed with limited data. Firstly, radar signal measurement and sparse representation are implemented, and the solution space is established by wavelet basis and Gauss random matrix; secondly, the matching function is considered as the fitness function, and the best fitness value is found by a PSO algorithm; then, a chaotic search was used to obtain the global optimal operator; finally, the root image is reconstructed by the optimal operators. A-scan data, B-scan data, and complex data from American GSSI GPR is used, respectively, in the experimental test. For B-scan data, the computation time was reduced 60 % and PSNR was improved 5.539 dB; for actual root data imaging, the reconstruction PSNR was 26.300 dB, and total computation time was only 67.210 s. The CPSO-OMP algorithm overcomes the problem of local optimum trapping and comprehensively enhances the precision during reconstruction.
文摘Objectives:To observe the clinical effect on the sequela of peripheral facial paralysis treated with the penetrating-sticking-pulling technique of acupuncture.Methods:A total of 53 patients with the sequela of peripheral facial paralysis were diagnosed and divided into an observation group(26 cases)and a control group(27 cases)according to the visiting sequence.In the observation group,the penetrating-sticking-pulling technique of acupuncture was adopted.The Sibai(四白ST 2),Quanliao(颧髎 SI 18)and Jiache(颊车ST 6)et al.were needling toward Dicang(地仓ST 4)separately.The combined acupoints were selected according to clinical symptoms of individual patient.In the control group,the routine acupuncture was used,in which,ST 2,EX-HN 5,ST 7,ST 6,and ST 4 as well as Hegu(合谷LI 4)on the healthy side were selected.The treatment was given once every two days and a 7-treatment made one course.There were 3 days at interval between the courses.After 2 courses of treatment,the facial nerve function,e.g.,Hourse-Brackmann(H-B)grading,Sunnybrook score and clinical effect were observed.Results:①After treatment,H-B grading and Sunnybrook score were better than those before treatment in either of the observation group or the control group(P<0.05,P<0.01).H-B grading and Sunnybrook score were(2.23±0.64)and(96.62±2.59),respectively,in the observation group after treatment and they were(3.21±0.43)and(80.33±3.16)respectively in the control group.H-B grading and Sunnybrook score in the observation group were better than the control group,indicating the significant differences(P<0.05,P<0.01).②The curative rate and the total effective rate were 69.23%and 96.15%,respectively,in the observation group and they were 37.04%and 81.48%,respectively,in the control group,presenting the significant differences(both P<0.05).Conclusion:The penetrating-sticking-pulling technique of acupuncture achieves the definite effect on the sequela of peripheral facial paralysis and this therapy deserves to be promoted in clinical practice.
文摘The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.
文摘Twenty samples of endothelia removed from normal and post penetrating keratoplas-ty (0.5,1,2,3 months after penetrating keratoplasty) were observed by scanning electron mi-croscopy.The photographs of the endothelia in graft-host junction were analyzed by computer-assisted image analysis system,and the morphometric indexes examined were area of the cells,perimeters,density,figure coefficient,long axis,coefficient of variation of the area,and oth-ers.Results showed that the morphology and the density of the endothelial cells changed obvi-ously after operation and improved slowly but progressively with time although at 3 monthspostoperatively some differences still existed.By using the new techniques,the experiment con-firmed and enriched the theories on the corneal endothelial wound-healing,revealing some ofthe new characters of the endothelial wound-healing following penetrating keratoplasty.
基金Supported by National Natural Science Foundation of China(No.30630063)
文摘AIM: To identify the current indications and the trend shifts for penetrating keraboplasty (PKP) in Shandong. METHODS: The medical charts of all patients who underwent PKP at Shandong Eye Institute from June 1, 2005 to May 31, 2010 were analysed retrospectively. RESULTS: A total of 875 patients (875 eyes) received PKP in this 5-year period, accounting for 61.6% of all corneal transplantation surgeries. The leading indications for PKP were infectious keratitis (37.1%), HSK (19.1%), keratoconus (11.2%), bullous keratopathy (8.5%), regrafting (6.7%) and corneal scarring (4.8%). The percentage of PKP for keratoconus declined year by year, whereas the percentage of bullous keratopathy had a mild annual increase. Fungal infections accounted for 65.2% of the infectious keratitis cases, remaining the leading cause of corneal infection. In addition, 54.1% of bullous keratopathy cases were associated with cataract surgery. The leading initial diagnoses associated with regrafting were infectious keratitis (38.9%), HSK (18.6%) and corneal burn (16.9%). The major causes of regrafting included graft endothelial dysfunction (39.0%), graft ulcer (28.8%) and primary disease recurrence (15.3%). CONCLUSION: Infectious keratitis remained the leading indication for PKP in Shandong, and fungal infections were still the major cause of corneal infections. There was an increasing trend in the percentage of PKP cases indicated for bullous keratopathy but a decline in the same for keratoconus. Even with a decline in the overall proportion among all corneal transplantation surgeries, PKP is still the major corneal transplant choice in Shandong.
文摘The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of curl interface underground or “v” figure complex model, it is difficult to realize. So it is important to forward the complex geoelectricity model. This paper takes two Maxwell’s vorticity equations as departure point, makes use of the principles of Yee’s space grid model theory and the basic principle finite difference time domain method, and deduces a GPR forward system of equation of two dimensional spaces. The Mur super absorbed boundary condition is adopted to solve the super strong reflection on the interceptive boundary when there is the forward simulation. And a self-made program is used to process forward simulation to two typical geoelectricity model.
