期刊文献+
共找到51,557篇文章
< 1 2 250 >
每页显示 20 50 100
DNA methylation regulates the extinction of fear memory 被引量:1
1
作者 Le Jiang Rui-Xue Ma +11 位作者 Er-Shu He Xiao-Ye Zheng Xin Peng Wen-Hao Ma Ying Li Han-Wei li Xue-Yan Zhang Jie-Yu Ji Yan-Jiao Li Shang-Lan Qu Li-Juan Li Zhi-Ting Gong 《World Journal of Psychiatry》 2025年第7期273-283,共11页
BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge... BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge.Fear conditioning and extinction in animal models offer insights into its mechanisms.Our previous research indi-cates that DNA methyltransferases play a role in fear memory renewal.AIM To investigate the role of DNA methylation in the extinction of fear memory,with the goal of identifying potential strategies to enhance the efficacy of exposure therapy for fear-related disorders.METHODS This study investigated the role of DNA methylation in fear memory extinction in mice.DNA methylation was manipulated using N-phthalyl-L-tryptophan(RG108)to reduce methylation and L-methionine injections to enhance it.Neuronal activity,and dendritic spine density was measured following extinction training.RESULTS RG108 suppressed extinction,reduced spine density,and inhibited neuronal activity.Methionine injections facilitated extinction.CONCLUSION DNA methylation is crucial for fear memory extinction.Enhancing methylation may improve the efficacy of exposure therapy,offering a potential strategy to treat fear-related disorders. 展开更多
关键词 RG108 DNA methylation Fear memory Exposure therapy extinction
暂未订购
Local Electric Fields Coupled with Cl^(−)Fixation Strategy for Improving Seawater Oxygen Reduction Reaction Performance
2
作者 Yu-Rong Liu Miao Zhang +8 位作者 Yan-Hui Yu Ya-Lin Liu Jing Li Xiao-Dong Shi Zhen-Ye Kang Dao-Xiong Wu Peng Rao Ying Liang Xin-Long Tian 《电化学(中英文)》 北大核心 2025年第9期46-55,共10页
Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field c... Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity. 展开更多
关键词 Seawater zinc-air battery Oxygen reduction reaction Local electric field Chloride ion fixation strategy Sin-gle-atom catalyst
在线阅读 下载PDF
Genomic insights into the absence of root nodule formation and nitrogen fixation in Zenia insignis
3
作者 Hang Yu Yongbin Lu +4 位作者 Chao Zhang Wenyuan Yang Hongjiang Xie Huiru Liu Haifeng Wang 《Journal of Genetics and Genomics》 2025年第6期860-863,共4页
Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly oc... Symbiotic nitrogen fixation in members of the Fabaceae family is highly efficient and beneficial for global agriculture,but not all species in this family form root nodules with rhizobial bacteria.Nodulation mainly occurs in plants belonging to the Papilionoideae and Caesalpinioideae subfamilies(Tederso0 et al.,2018;van Velzen et al.,2019).Nodulation mechanisms in Fabaceae are well studied(Yang et al.,2022),and genomic comparisons of nodulating and non-nodulating host species can provide valuable insights into the evolutionary and genetic basis of this key process. 展开更多
关键词 nitrogen fixation genomic insights rhizobial bacterianodulation symbiotic nitrogen fixation root nodule formation Zenia insignis genomic comparisons FABACEAE
原文传递
Heterogeneous iron-based catalysts for a sustainable photoinduced nitrogen fixation
4
作者 Amalia M.Grigoras Federica Valentini +1 位作者 Loredana Latterini Luigi Vaccaro 《Green Energy & Environment》 2025年第4期733-755,共23页
Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also par... Ammonia is nowadays one of the most important commodities chemicals intensively produced at about 175 million tons per year,contributing to 1.8%of the global energy demand.The constantly increasing NH3 demand also paralleleds by the high CO_(2) emissions associated with its production.Therefore,decarbonizing NH3 synthesis is one of the most urgent contemporary challenges.Taking inspiration from Nature,solar-driven nitrogen fixation under mild conditions is one of the most promising yet challenging alternatives to classic methods.In this review,we focused our attention on the photocatalytic methods for the synthesis of ammonia;in particular,we concentrated on stable and recyclable heterogeneous Fe-based photocatalysts for producing NH3.Indeed,recoverable and widely abundant and low-cost iron catalysts may represent a very promising tool for future sustainable access to this largely desired chemical target.After an overview of the pioneering works on Fe-driven nitrogen photofixation,the recent strategies on the use of Fe are herein reported.Compared with pristine photocatalysts,adding Fe as dopant or composite and heterojunction highly enhances the photocatalytic performances,opening the way to sustainable and low-cost nitrogen production. 展开更多
关键词 Nitrogen fixation AMMONIA Iron photocatalysts PHOTOCATALYSIS
在线阅读 下载PDF
Insights of stearic acid/polypyrrole superhydrophobic coating on controlling corrosion,antibacterial and cytocompatibility of biodegradable Mg alloy and its implication on fracture fixation
5
作者 Satyabrata Nigamananda Sahoo Pritish Rath +4 位作者 Santanu Mandal Meeta Ashok Kamde Partha Saha Samit Kumar Nandi Mangal Roy 《Journal of Magnesium and Alloys》 2025年第12期6195-6220,共26页
Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce a... Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce alloy through a stearic acid-treated polypyrrole coating,which developed superhydrophobic surface(contact angle∼153°)that drastically enhanced the corrosion resistance(more than 85%efficacy).Cerium addition to Mg alloy results basal texture strengthening and grain refinement,resulting in improved mechanical properties.All the specimens exhibited excellent antibacterial performance against gram-negative E.Coli(DH5α)and gram positive S.aureus bacteria.The oligodynamic effect of polypyrrole coating leads to complete bacterial mitigation.Non-toxic nature of the specimens was studied by MC3T3-E1 cell proliferation and differentiation in indirect cell culture method.Improved corrosion resistance of the coated specimen leads to enhanced cell proliferation and osteogenic differentiation.Hard tissue histology and micro-CT analysis exhibited higher fraction of newly formed callus tissues and highest bone-implant integration across the coated specimen,when implanted in rabbit femur.Efficacy of the material in fracture healing was evaluated by implanting bone plate and screw in a clinically fractured goat tibia.At 3 months,complete fracture healed with no vital organ toxicity was observed for the coated specimen.The present results suggest that Ce addition and polypyrrole coating are effective ways to modulate the corrosion and biocompatibility behavior making it a potential candidate for fracture fixation applications. 展开更多
关键词 POLYPYRROLE Superhydrophobic coating ANTIBACTERIAL CYTOCOMPATIBILITY Fracture fixation
在线阅读 下载PDF
How Fear Memory is Updated:From Reconsolidation to Extinction?
6
作者 Jiahui Chen Zhuowen Fang +2 位作者 Xiaolan Zhang Yanrong Zheng Zhong Chen 《Neuroscience Bulletin》 2025年第6期1054-1084,共31页
Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forget... Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forgetting,suggesting the potential to erase fear memories through timely interventions.Conventional strategies such as medications or electroconvulsive therapy often fail to provide permanent relief and come with significant side-effects.This review explores how fear memory may be erased,particularly focusing on the mnemonic phases of reconsolidation and extinction.Reconsolidation strengthens memory,while extinction weakens it.Interfering with memory reconsolidation could diminish the fear response.Alternatively,the extinction of acquired memory could reduce the fear memory response.This review summarizes experimental animal models of PTSD,examines the nature and epidemiology of reconsolidation to extinction,and discusses current behavioral therapy aimed at transforming fear memories to treat PTSD.In sum,understanding how fear memory updates holds significant promise for PTSD treatment. 展开更多
关键词 Post-traumatic stress disorder Fear memory RECONSOLIDATION extinction Engram
原文传递
Cerium-based metal-organic framework-modified natural mineral vermiculite for photocatalytic nitrogen fixation under visible-light irradiation
7
作者 Sixiao Liu Tianyi Wang +2 位作者 Lei Zhang Chengyin Wang Huan Pang 《Chinese Chemical Letters》 2025年第3期177-181,共5页
In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal... In order to protect the environment and economize energy,a nitrogen-fixing photocatalyst,VMCeact,is investigated in this work.This catalyst is prepared from a natural mineral,vermiculite,and modified by Ce-based metal-organic framework,Ce-UiO-66.Vermiculite was treated with formic acid;thus,Ce-UiO-66 particles grew in-situ on vermiculite;then,Ce-UiO-66 particles were activated by ultraviolet irradiation.The vermiculite absorbed visible light with a narrow band gap,and transferred photogenerated electrons to the active sites on Ce-UiO-66.Moreover,the lamella structure of vermiculite protected Ce-UiO-66 during photocatalytic process.Therefore,with only 45.92 wt%of Ce-UiO-66,the nitrogen fixation performance of VMCeact was 2.29 times that of pure activated Ce-UiO-66 particles under 455nm light irradiation(apparent quantum efficiency of 4.49%),and retained at least 96.05%performance after 7×24 h of photocatalytic reaction.This cost-reduced,efficient and stable photocatalyst has the opportunity to facilitate environmentally friendly ammonia production. 展开更多
关键词 Metal-organic frameworks VERMICULITE Nitrogen fixation VISIBLE-LIGHT LOW-COST
原文传递
Clinical Efficacy of Different Internal Fixation Implants for Post-Traumatic Nonunion of Limb Fractures:A Comparative Study
8
作者 Li He Cheng Weiqiang Zhu Dingguo 《Science International Innovative Medicine》 2025年第2期25-30,共6页
To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center... To compare the clinical efficacy of locking plate(LP)fixation and intramedullary nail(IMN)fixation for the treatment of post-traumatic nonunion of diaphyseal fractures of the femur and tibia.Methods:This single-center retrospective comparative study included 50 adult patients with aseptic nonunion of femoral or tibial diaphyseal fractures treated at our institution between January 2015 and January 2025.Patients underwent either locking-plate(LP)fixation(n=25)or intramedullary nailing(IMN)(n=25).The primary outcome was radiographic union at 12 months postoperatively.Secondary outcomes included time to union,operative time,intraoperative blood loss,length of hospital stay,incidence of complications(superficial/deep infection,implant failure,malunion),and 12-month functional status assessed by the Lower Extremity Functional Scale(LEFS).Statistical comparisons used Welch t tests for continuous variables and χ^(2) or Fisher exact tests for categorical variables.The protocol received institutional review board approval with waiver of informed consent.Results:Among 50 patients(LP=25;IMN=25),the 12-month union rate was 88.00%(22/25)in the LP group and 96.00%(24/25)in the IMN group(p=0.609).Time to union was shorter with IMN(6.20±1.83 vs 7.51±2.12 months;p=0.023).Operative time(110.52±25.23 vs 145.81±30.21 min;p<0.01)and intraoperative blood loss(250.41±80.64 vs 350.22±95.30 ml;p<0.01)favored IMN.Length of hospital stay was similar(6.24±1.83 vs 6.82±2.11 days;p=0.284).The incidence of superficial wound infection did not differ significantly(12.00%vs 4.00%;p=0.609).Twelve-month LEFS scores were comparable(65.44±10.21 vs 67.10±9.83;p=0.451).Conclusion:Both locking plate and intramedullary nail fixation are effective in the treatment of femoral and tibial nonunion,with high rates of union and good functional outcomes.Intramedullary nailing may be associated with a shorter time to union,reduced operative time and blood loss,and a lower risk of superficial wound infection compared to locking plate fixation.The choice of implant should be individualized based on fracture characteristics,patient factors,and surgeon preference. 展开更多
关键词 NONUNION Limb Fractures Internal fixation Locking Plate Intramedullary Nail Clinical Efficacy
暂未订购
Elevated extinction risk of low-elevation populations of two songbirds on the Taiwan island
9
作者 Xuntao Ma Yadan Liu +2 位作者 Zhang Zhang Mingwang Zhang Feng Dong 《Avian Research》 2025年第3期467-472,共6页
Prevailing concerns on mountainous biodiversity are concentrated on the impacts of climate change at higher elevations. However, the lower elevations are facing additional human disturbance and are expected to suffer ... Prevailing concerns on mountainous biodiversity are concentrated on the impacts of climate change at higher elevations. However, the lower elevations are facing additional human disturbance and are expected to suffer from higher extinction risk but have attracted less conservation attention. Here, we employed population genomics to compare extinction risk two common songbirds—the Vinous-throated Parrotbill (Sinosuthora webbiana) and the Rufous-capped Babbler (Cyanoderma ruficeps)—at lower and higher elevations on the Taiwan island. As the result, we observed decreased genetic diversity and increased genetic load and thus elevated extinction risk in the low-elevation populations of both birds in the eastern slope of the Central Mountains on the Taiwan island. In contrast, genetic-load patterns of both birds in the western slope might be confused by substantial gene flow across lower and higher elevations. These results, on the one hand, call for conservation efforts to lower elevations in mountains and, on the other hand, highlight the importance of population connection in maintaining population viability under impending global change. 展开更多
关键词 extinction risk Genetic load Human disturbance Mountainous biodiversityi Population genomics
在线阅读 下载PDF
Z-scheme g-C_(3)N_(4)/MIL-101(Fe) for enhanced photocatalytic nitrogen fixation: structure, performance and mechanism studies
10
作者 LI Meixi CUI Donghui +2 位作者 YANG Xue ZHANG Tingting LI Fengyan 《分子科学学报》 2025年第1期44-54,共11页
The replacement of energy-intensive Haber-Bosch technique for ammonia production to mitigate global warming is increasingly emphasized.In this paper,we report the preparation of Z-scheme heterojunction nanocomposites ... The replacement of energy-intensive Haber-Bosch technique for ammonia production to mitigate global warming is increasingly emphasized.In this paper,we report the preparation of Z-scheme heterojunction nanocomposites for photocatalytic nitrogen fixation by coupling ultrathin two-dimensional g-C_(3)N_(4) nanosheets with MIL-101(Fe)using a solvothermal method.Methanol was used as a hole sacrificing reagent to strengthen the catalytic performance.The highest NH3 yield of the composites under full spectrum irradiation was 472.8μmol·g^(−1)·h^(−1),which is about 3.5 times that of MIL-101(Fe).From BET results,photocatalyst with high specific surface area has superior nitrogen fixation performance.The results of PL,EIS,UPS,and ESR show that the presence of Z-scheme heterojunction is largely able to facilitate the separation of electrons and holes.It is one reason for improving performance of nitrogen fixation.The study has provided a viable approach to construct heterojunction photocatalysts with outstanding nitrogen fixation performance. 展开更多
关键词 PHOTOCATALYTIC Z-scheme heterojunction MIL-101(Fe) nitrogen fixation solvothermal method
原文传递
Treatment of lumbar tuberculosis with minimally invasive anterior lesion clearance combined with posterior fixation
11
作者 Fei-Fei Pu Xiang-Lin Peng +6 位作者 Fang-Zheng Zhou Xiao-Long Zhao Ling Yang Jun-Qing Cao Liu Wei Jing Feng Ping Xia 《World Journal of Orthopedics》 2025年第7期64-71,共8页
BACKGROUND Spinal tuberculosis,a destructive extrapulmonary form,often causes severe deformity and neurological deficits.Surgical intervention aims to debride lesions,reconstruct stability,and correct deformities.This... BACKGROUND Spinal tuberculosis,a destructive extrapulmonary form,often causes severe deformity and neurological deficits.Surgical intervention aims to debride lesions,reconstruct stability,and correct deformities.This study evaluates a combined posterior fixation and minimally invasive anterior approach for lumbar tuberculosis.AIM To evaluate the clinical outcomes and radiological parameters of posterior internal fixation combined with minimally invasive anterior lesion clearance and bone graft fusion for the treatment of lumbar tuberculosis.METHODS Clinical data from 24 patients with lumbar tuberculosis who underwent posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance were analyzed.The Cobb angle,visual analog scale(VAS)score,and Frankel classification were statistically assessed preoperatively and postoperatively.Complications and bone graft fusion were also recorded.RESULTS Wounds healed in the first stage in 22 patients;one patient developed a posterior incisional sinus tract,and one experienced postoperative tuberculosis recurrence.At the final follow-up,according to the Frankel classification,there were 1,2,and 21 cases classified as grade C,grade D,and grade E,respectively.By the last follow-up,the Cobb angle,VAS score,and erythrocyte sedimentation rate had all decreased.Both X-ray and computed tomography images confirmed bone healing.The fusion time ranged from 3 to 9 months,with an average of 5.2 months.CONCLUSION Posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance is an effective and safe treatment for lumbar tuberculosis. 展开更多
关键词 Lumbar tuberculosis Pedicle screw fixation Minimally surgery Lesion removal
暂未订购
Extinction and Optimal Control of Stochastic Epidemic Model with Multiple Vaccinations and Time Delay
12
作者 YANG Rujie QIU Hong JU Xuewei 《数学理论与应用》 2025年第2期110-121,共12页
In this paper,based on the SVIQR model we develop a stochastic epidemic model with multiple vaccinations and time delay.Firstly,we prove the existence and uniqueness of the global positive solution of the model,and co... In this paper,based on the SVIQR model we develop a stochastic epidemic model with multiple vaccinations and time delay.Firstly,we prove the existence and uniqueness of the global positive solution of the model,and construct suitable functions to obtain sufficient conditions for disease extinction.Secondly,in order to effectively control the spread of the disease,appropriate control strategies are formulated by using optimal control theory.Finally,the results are verified by numerical simulation. 展开更多
关键词 Stochastic epidemic model Multiple vaccinations extinction of disease Isolation delay Optimal control
在线阅读 下载PDF
Rare earth-doped carbon nitride composite Ce-based metal-organic framework for visible light-driven nitrogen fixation catalysis
13
作者 Shan Zhu Sixiao Liu +6 位作者 Lei Zhang Hang Liu Xiaoyu Zhou Yayu Mao Linshuang Zhang Tianyi Wang Chengyin Wang 《Journal of Rare Earths》 2025年第8期1607-1615,I0002,共10页
The utilization of visible light for photocatalytic nitrogen fixation offers a sustainable and eco-friendly strategy for the production of ammonia.The present study focuses on the synthesis of a series of rare earth-d... The utilization of visible light for photocatalytic nitrogen fixation offers a sustainable and eco-friendly strategy for the production of ammonia.The present study focuses on the synthesis of a series of rare earth-doped carbon nitride composite ultraviolet-activated Ce-UiO-66 catalysts,denoted as RECNactMOF,for efficient nitrogen fixation.Rare earth doping modulates the band structure of carbon nitride,facilitating the formation of a type-I heterojunction with Ce-UiO-66 and promoting photocarrier generation at nitrogen fixation sites.Among these,Sm-doped SmCN-actMOF exhibits high visible-light absorption and efficient utilization of photocarriers,resulting in an apparent quantum efficiency(AQE)of 1.58%under 495 nm light irradiation.This study provides a pathway for enhancing the nitrogen fixation efficiency of photocatalysts through the incorporation of rare earth elements,and expanding the potential applications of rare earth materials in the field of photocatalysis. 展开更多
关键词 Rare earth metal doping Metal-organic framework PHOTOCATALYST Nitrogen fixation Carbon nitride
原文传递
Observation on the therapeutic effect of a modified Devine procedure with subcutaneous sliding fixation method for concealed penis
14
作者 Mohammed Abdulkarem Al-Qaisi Hai-Fu Tian +8 位作者 Jia-Jin Feng Ke-Ming Chen Jin Zhang Yun-Shang Tuo Xue-Hao Wang Bin-Cheng Huang Muhammad Arslan Ul Hassan Rui He Guang-Yong Li 《Asian Journal of Andrology》 2025年第4期470-474,共5页
To evaluate the therapeutic effect of a modified Devine procedure with a subcutaneous sliding fixation method for the treatment of congenital concealed penis,we retrospectively selected 45 patients with congenital con... To evaluate the therapeutic effect of a modified Devine procedure with a subcutaneous sliding fixation method for the treatment of congenital concealed penis,we retrospectively selected 45 patients with congenital concealed penises who were admitted to General Hospital of Ningxia Medical University(Yinchuan,China)between September 2020 and November 2023.In all cases,the penis was observed to be short,and retracting the skin at the base revealed a normal penile body,which immediately returned to its original position upon release.All patients underwent the modified Devine procedure with subcutaneous sliding fixation and completed a 12-week postoperative follow-up.A statistically significant increase in penile length was observed postoperatively,with the median length increasing from 4.0(interquartile range[IQR]:3.5–4.8;95%confidence interval[CI]:3.9–4.4)cm to 8.0(IQR:7.8–8.0;95%CI:7.7–7.9)cm,with P<0.001.The parents were satisfied with the outcomes,including increased penile length,improved hygiene,and enhanced esthetics.Except for mild foreskin edema in all cases,no complications(such as infections,skin necrosis,or penile retraction)were observed.The edema was resolved within 4 weeks after the operation.This study demonstrates that the modified Devine procedure utilizing the subcutaneous sliding fixation method yields excellent outcomes with minimal postoperative complications,reduced penile retraction,and high satisfaction rates among patients and their families. 展开更多
关键词 congenital concealed penis fixation method modified Devine surgery
原文传递
Impact of the Ilizarov apparatus on external fixation: Current modifications of the 75-year-old orthopedic tool
15
作者 Ilia Sutyagin Tatiana A Malkova 《World Journal of Orthopedics》 2025年第11期44-55,共12页
The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios re... The Ilizarov apparatus was designed by its author 75 years ago and addresses a wide range of orthopedic conditions.Its classical assemblies are still self-sufficient and versatile.However,certain clinical scenarios require a more specialized approach,and some groups of patients may benefit from customized Ilizarov constructs.Engineering science has designed various external fixators for orthopedic purposes,and some of those have become the gold standard for specific clinical tasks.We aimed to determine the current state and novel modifications of specialized external fixators for specific clinical situations which are based on the principles of the Ilizarov method.They are half-pin-based fixators for temporal fracture fixation,ring or hybrid devices for gradual deformity correction,and compression-distraction devices tailored for definite limb segments.Gradual correction of deformities can be achieved with external hexapods incorporating universal reduction units.Alternatively,external fixators with special connection mechanisms are able to provide independent movement of the rings in six degrees of freedom.Deformity correction can be performed with combined or sequential use of external and internal fixators.Special devices were developed for moving the split fragment for revascularization of the tibia.The units of external frames on the foot were modified to consider its complex anatomy and the clinical needs ranging from correction of multi-plane deformities,joint arthrodesis to distraction arthroplasty.Mini-fixators are compact external fixators for small bones of the hand and foot.The varieties of external fixators based on the Ilizarov principles have been designed to fulfill an ultimate goal of improving treatment outcomes. 展开更多
关键词 Ilizarov apparatus External fixation Distraction osteogenesis Bone lengthening Bone deformity Hexapod frame Mini-fixator
暂未订购
Enhancing long-term fixation in thoracolumbar injuries:From screw design to bone quality optimization
16
作者 Musa Ergin Süha A Aktaş 《World Journal of Orthopedics》 2025年第12期7-11,共5页
Pedicle screw fixation remains the gold standard for stabilizing unstable thoracolumbar fractures.However,ensuring long-term instrumentation stability continues to challenge both surgeons and implant designers.The stu... Pedicle screw fixation remains the gold standard for stabilizing unstable thoracolumbar fractures.However,ensuring long-term instrumentation stability continues to challenge both surgeons and implant designers.The study by Bokov et al contributes significantly to this discussion,identifying predictors of pedicle screw loosening such as low bone radiodensity,longer fixation constructs,and extensive decompression.Adjunctive strategies-auxiliary posterior fusion,anterior column reconstruction,and intermediate screw usage-support an individualized,biomechanically sound surgical plan.In this article,we explore the clinical relevance of these findings within spinal trauma care.We emphasize the role of preoperative bone quality assessment,including computed tomography-based Hounsfield unit analysis and magnetic resonance imaging-derived vertebral bone quality score,as modifiable predictors of long-term outcomes.We also discuss innovations in screw design,surface coatings,and patient-specific planning to reduce failure risk.Furthermore,emerging technologies such as finite element modeling and 3D-printed instrumentation may refine patient-specific strategies.By integrating biomechanical principles with personalized surgical planning,future approaches may enhance fixation durability.Ultimately,aligning mechanical stability with biological sustainability is critical to reducing implant failure in complex thoracolumbar trauma cases. 展开更多
关键词 Thoracolumbar fractures Pedicle screw loosening Bone quality Finite element modeling Spinal fixation
暂未订购
Contrasting controls on symbiotic and asymbiotic nitrogen fixation rates along altitudinal gradients in subtropical forests
17
作者 Xibin Sun Zhenchuan Wang +2 位作者 Chengjin Chu Yingming Zhang Hao Chen 《Forest Ecosystems》 2025年第5期791-798,共8页
Symbiotic and asymbiotic nitrogen fixation(SNF and ANF),two forms of biological nitrogen(N)fixation,are the main pathways for external N inputs into natural terrestrial ecosystems.However,the regulatory mechanisms of ... Symbiotic and asymbiotic nitrogen fixation(SNF and ANF),two forms of biological nitrogen(N)fixation,are the main pathways for external N inputs into natural terrestrial ecosystems.However,the regulatory mechanisms of SNF and ANF,particularly in response to changing environmental conditions,remain poorly understood.Here,we investigated changes in SNF and ANF rates along two altitudinal gradients in two subtropical forests on soils with granite and slate parent materials.Our results revealed distinct patterns for SNF and ANF rates.SNF rates consistently declined with increasing altitude,whereas ANF rates initially increased at lower altitudes but declined at higher altitudes.These contrasting trends were attributed to divergent regulatory mechanisms of SNF and ANF rates.Specifically,the decrease in SNF rates was primarily driven by increased soil N availability and decreased air temperature.However,the drivers of ANF rates shifted from soil properties(e.g.,phosphorus,iron,and moisture)at lower altitudes to climatic factors(e.g.,air temperature)at higher altitudes.We also observed opposite trends of SNF and ANF between forests on granite and slate,demonstrating that lithology is an important driver of both SNF and ANF.Collectively,our findings highlight the divergent mechanisms regulating SNF and ANF in subtropical forests,which contribute to improving the mechanistic representation of biological N fixation in Earth system models. 展开更多
关键词 Biological nitrogen fixation(BNF) Elevation LEGUME LITTER MOSS Parent material Soil
在线阅读 下载PDF
Mechanical Energy Drives the Growth and Carbon Fixation of Electroactive Microorganisms
18
作者 Guoping Ren Jie Ye +4 位作者 Lu Liu Andong Hu Kenneth H.Nealson Christopher Rensing Shungui Zhou 《Engineering》 2025年第4期194-203,共10页
Phototrophy and chemotrophy are two dominant types of microbial metabolism.However,to date,the potential of the ubiquitous and versatile mechanical energy as a renewable energy source to drive the growth of microorgan... Phototrophy and chemotrophy are two dominant types of microbial metabolism.However,to date,the potential of the ubiquitous and versatile mechanical energy as a renewable energy source to drive the growth of microorganisms has remained unknown and not utilized.Here,we present evidence in favor of a previously unidentified metabolic pathway,in which the electronic energy produced from mechanical energy by the piezoelectric materials is used to support the growth of microorganisms.When electroactive microorganism Rhodopseudomonas palustris(R.palustris;with barium titanate nanoparticles)was mechanically stirred,a powerful biohybrid piezoelectric effect(BPE)enabled sustainable carbon fixation coupled with nitrate reduction.Transcriptomic analyses demonstrated that mechanical stirring of the bacteria–barium titanate biohybrid led to upregulation of genes encoding functions involved in electron and energy transfer in R.palustris.Studies with other electroactive microorganisms suggested that the ability of microbes to utilize BPE may be a common phenomenon in the microbial world.Taken together,these findings imply a long-neglected and potentially important microbial metabolic pathway,with potential importance to microbial survival in the energy-limited environments. 展开更多
关键词 Mechanical energy Biohybrid piezoelectric effect Microbial metabolism Carbon fixation Nitrate reduction
在线阅读 下载PDF
Closed Reduction and Minimally Invasive Fixation for the Treatment of Bilateral Displaced Posterior Pelvic Ring Disruption
19
作者 Zhen Wang Zhe Xu +5 位作者 Peng-hui Xiang Mei-qi Gu Rui Zhang Hua Chen Li He Cheng-la Yi 《Current Medical Science》 2025年第1期137-145,共9页
Objective Close reduction and internal fixation have gained popularity for the treatment of pelvic fractures.However,the closed reduction of bilateral displaced posterior pelvic ring disruption is a great challenge ev... Objective Close reduction and internal fixation have gained popularity for the treatment of pelvic fractures.However,the closed reduction of bilateral displaced posterior pelvic ring disruption is a great challenge even for the most experienced surgeon.In this study,we describe in detail a novel unlocking closed reduction technique(UCRT)frame that allows strong traction for bilateral posterior pelvic ring displacement and presents preliminary clinical outcomes.Methods We retrospectively reviewed 32 patients with bilateral displaced posterior pelvic ring disruptions(AO/OTA 61-C2 and C3)who were initially treated with this technique between July 2017 and July 2022.According to the AO/OTA clas-sification,there were 9 cases(28.12%)of 61-C2,and 23 cases(71.88%)of 61-C3.There were 11 males,21 females,with an average age of 38.1 years.The interval from injury to operation was 4-27 days,with a cut-off of 12.5 days(receiver operat-ing characteristic curve).Operative time,blood loss,and postoperative radiographic findings were recorded.The functional outcomes and complications were followed.Results A total of 30(93.8%)patients achieved successful closed reduction,whereas 2 required open reduction.The success-ful closed reduction rate was 95.5%(21/22)in patients whose injury-to-operation time was less than 12.5 days.The vertical displacement percent correction of the obviously displaced hemipelvis was 70.20%±16.79%on average.The average degree of pelvic deformity correction was 64.86%±17.71%.Thirty patients were followed up for at least 12 months(12-36 months),and no complications of nonunion or redisplacement were observed.The Matta-Tornetta scoring standard revealed that the excellent(25/30)and good(4/30)rate was 96.7%.The Majeed clinical efficacy score revealed that the overall excellent and good rate was 100%.One patient had INFIX-related infection,and 2 reported numbness in the lateral thigh.The numbness was improved after INFIX removal.Conclusions This study presents an updated technique for closed reduction using a UCRT frame for bilateral posterior pelvic ring disruption,which has been shown to be effective,as indicated by excellent surgical and functional outcomes. 展开更多
关键词 Pelvic fractures Unlocking closed reduction technique Minimally invasive internal fixation
暂未订购
Traditional Chinese bone-setting combined with percutaneous screw fixation for comminuted calcaneal fractures: A case report and review of literature
20
作者 Hui-Chun Huang Yong-Feng Che +3 位作者 He Sun Yi-Sheng Xu Hua-Yin Gao Xiu-Shu Tang 《World Journal of Orthopedics》 2025年第11期161-170,共10页
BACKGROUND Comminuted calcaneal fractures present significant treatment challenges.Open reduction and internal fixation carries risks such as infection and skin necrosis,while minimally invasive techniques may comprom... BACKGROUND Comminuted calcaneal fractures present significant treatment challenges.Open reduction and internal fixation carries risks such as infection and skin necrosis,while minimally invasive techniques may compromise reduction stability.Conservative management is generally limited to minimally displaced fractures.Traditional Chinese manual bone-setting has a long history in fracture treatment and is renowned globally for achieving functional reduction.It offers distinct advantages including lower cost,minimal soft tissue trauma,and the avoidance of expensive reduction equipment or internal fixation materials.CASE SUMMARY A 60-year-old female presented with left foot pain and limited mobility following a fall.Computed tomography scan revealed a Sanders type IV calcaneal fracture with a Böhler angle of 0°.A standardized,stepwise Traditional Chinese manual bone-setting was initially performed,followed by percutaneous screw fixation through several mini-incisions after satisfactory alignment was confirmed under fluoroscopy.The Visual Analog Scale score decreased from 5 on postoperative day 1 to 3 by day 3.The American Orthopaedic Foot and Ankle Society score improved from 73 at 6 weeks to 90 at 3 months,indicating rapid functional recovery and high patient satisfaction.At 7 months postoperatively,the American Orthopaedic Foot and Ankle Society score reached 95,prompting removal of internal fixation.At the 6-year follow-up,reduction remained well maintained,with the Böhler angle preserved at 22°.CONCLUSION The combination of Traditional Chinese manual bone-setting and percutaneous screw fixation achieved satisfactory functional reduction for comminuted calcaneal fractures. 展开更多
关键词 Chinese manipulative bone-setting Calcaneal fracture Minimally invasive procedure Percutaneous screw fixation Case report
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部