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
In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enh...In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system （IMS）. Three N rates, NN （no nitrogen application）, LN （lower N application： 270 kg N ha-1）, and CN （conventional N application： 330 kg N ha-1）, and three topdressing distances of LN （LND）, e.g., 15 cm （LND1）, 30 cm （LND2） and 45 cm （LND3） from maize rows were evaluated. At the beginning seed stage （R5）, the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant-1 and 0.14 mL h-1 plant-1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency （NAE） of IMS under CN were 308.3 kg ha-1, 28.5%, and 5.7 kg grain kg-1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15-30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.展开更多
BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish diffe...BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish different finite element models for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.METHODS The three-dimensional models of the normal and fractured pelvis and the five internal fixations were established using the computed tomography data of the pelvis of a living volunteer.After the vertebral body model was inserted in the way of origin matching and all cancellous bones were copied using the duplicated cancellous bone model as the subtractive entity,the Boolean operation was performed on the pelvis model to obtain the model of the complete pelvis cortical and cancellous bones.RESULTS In the standing position,the maximum stress was 46.21 MPa.In the sitting position,the sacrum bore the simulated gravity load at the upper end.When comparing the five fixations,there were no significant differences in the stress mean values among groups(sitting:P=0.9794;standing:P=0.9741).In terms of displacement,the average displacement of the internal iliac plate group was smaller than that of the spring plate group(P=0.002),and no differences were observed between the other pairs of groups(all P>0.05).In the standing position,there were no significant differences in the mean value of displacement among the groups(P=0.2985).It can be seen from the stress nephogram of the internal fixations in different positions that the stress of the internal fixation was mainly concentrated in the fracture segment.CONCLUSION There were no significant differences among the fixations for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.展开更多
For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the ...For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the liver fine structure and experience with the numerous artifacts in fixation,embedding,sectioning,contrast staining and microscopic imaging.Hence,the aim of this paper is to present a detailed summary of different methods for the preparation of hepatic cells and tissue,for the purpose of preserving long-standing expertise and to encourage new investigators and clinicians to include EM studies of liver cells and tissue in their projects.展开更多
Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed i...Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.展开更多
The effects of three fixation methods( steaming,blanching and microwave fixation) on chemical composition and sensory quality of Lycium ruthenicum bud-tea were investigated.The results showed the fixation technique( t...The effects of three fixation methods( steaming,blanching and microwave fixation) on chemical composition and sensory quality of Lycium ruthenicum bud-tea were investigated.The results showed the fixation technique( the leaf weight 3 g/cm^2,the time 1.5 min,and the temperature 100 ℃) was the best,which was beneficial to the conservation of free amino acid and soluble sugar in L.ruthenicum bud-tea.The loss of chlorophyll was limited,and the score of sensory quality review was higher.展开更多
Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin thre...Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.展开更多
Rupture of the anterior cruciate ligament(ACL)is a common orthopedic injury.Various graft options are available for the reconstruction of ruptured ACL.Using the hamstring muscle as an autograft was first described in ...Rupture of the anterior cruciate ligament(ACL)is a common orthopedic injury.Various graft options are available for the reconstruction of ruptured ACL.Using the hamstring muscle as an autograft was first described in 1934,and it remains a commonly harvested graft for ACL reconstruction.Hamstring autografts can be harvested using the traditional anteromedial approach or the newer posteromedial technique.An isolated semitendinosus tendon can be used or combined with the gracilis tendon.There are numerous methods for graft fixation,such as intra-tunnel or extra-tunnel fixation.This comprehensive review discusses the different hamstring muscle harvesting techniques and graft preparation options and fixation methods.It provides a comprehensive overview for choosing the optimal surgical technique when treating patients.展开更多
AIM:To explore the long term therapeutic effects of surgical treatment for isthmic spondylolisthesis.METHODS:42 cases of isthmic spondylolisthesis were analyzed retrospectively among which 13 cases underwent simple lu...AIM:To explore the long term therapeutic effects of surgical treatment for isthmic spondylolisthesis.METHODS:42 cases of isthmic spondylolisthesis were analyzed retrospectively among which 13 cases underwent simple lumbar interlaminar bone implant and 29 cases underwent transpedicular fixation combined with bone implantation.Assessment was made according to JOA standards before and after treatment.RESULTS:At a 3 years of follow up assessment,the functional outcome in transpedicular fixation assessed by JOA was excellent and good in 79.3%as compared with the group without fixation in which the excellent and good result was 76.9%.The level of pain and functional disability were similar in the two groups,but fusion rate in the group with transpedicular fixation was higher than that in group without it.CONCLUSION:Surgical treatment for isthmic spondylolisthesis improves function and relieves pain.展开更多
Objective: to compare the different effects of different internal fixation methods in the treatment of posterior malleolus fracture. Methods: from January to December 2020 in our hospital orthopaedic hospital for trea...Objective: to compare the different effects of different internal fixation methods in the treatment of posterior malleolus fracture. Methods: from January to December 2020 in our hospital orthopaedic hospital for treatment of 80 patients with fracture of ankle after, for example, different internal fixation method to random grouping, average of all of these patients, line 2 pieces of 4 mm steel half thread tension screw fixed way as the control group, the "T" type three to four screws hole radius far end plate internal fixation method of patients as a team, to compare the clinical efficacy of two groups of patients and fixed strength. Results: clinical efficacy and intensity of fixation were compared between the two groups one month after operation. The results showed that there were significant differences in the total effective rate and fixation intensity between the two groups, and those in the study group were significantly higher than those in the control group (P < 0.05). Conclusion: the "T" type three-hole distal radius plate internal fixation for posterior ankle fracture surgery can significantly increase the stability of the body and help patients realize functional exercise as soon as possible. It is an excellent internal fixation method in clinical practice and is worthy of vigorously promoting and applying in clinical practice.展开更多
Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimens...BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimensional model of the femur was established from sectional computed tomography images,and an internal fixation model was established.Finite element analysis of the femur model was established,and three intertrochanteric fracture models,medial defect,lateral defect,and medial-lateral defects,were simulated.Displacement and stress distribution after fixation with a proximal femoral anti-rotation intramedullary nail(PFNA),integrated dual-screw fixation(ITN),PFNA+wire,PFNA+plate,and PFNA+wire+plate were compared during daily activities.RESULTS The maximum displacement and stress of PFNA and ITN were 3.51 mm/473 MPa and 2.80 mm/588 MPa for medial defects;2.55 mm/288 MPa and 2.10 mm/307 MPa for lateral defects;and 3.84 mm/653 MPa and 3.44 mm/641 MPa for mediallateral defects,respectively.For medial-lateral defects,reconstructing the medial side alone changed the maximum displacement and stress to 2.79 mm/515 MPa;reconstructing the lateral side changed them to 3.72 mm/608 MPa,when both sides were reconstructed,they changed to 2.42 mm/309 MPa.CONCLUSION For medial defects,intramedullary fixation would allow early low-intensity rehabilitation exercise,and ITN rather than PFNA reduces the risk of varus and cut-out;for lateral wall defects or weakness,intram-edullary fixation allows higher-intensity rehabilitation exercise,and ITN reduces the risk of varus.For both medial and lateral defects,intramedullary fixation alone will not allow early functional exercise,but locating lateral or medial reconstruction will.For defects in both the inner and outer sides,if reconstruction cannot be completed,ITN is more stable.展开更多
The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytica...The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.展开更多
Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vi...Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.展开更多
In order to solve the problem of the variable coefficient ordinary differen-tial equation on the bounded domain,the Lagrange interpolation method is used to approximate the exact solution of the equation,and the error...In order to solve the problem of the variable coefficient ordinary differen-tial equation on the bounded domain,the Lagrange interpolation method is used to approximate the exact solution of the equation,and the error between the numerical solution and the exact solution is obtained,and then compared with the error formed by the difference method,it is concluded that the Lagrange interpolation method is more effective in solving the variable coefficient ordinary differential equation.展开更多
Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.Howev...Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.However,the widened hydraulic excitation frequency may satisfy the blade resonance due to the time variation in the velocity and angle of attack of the ocean current,even resulting in blade fatigue and destructively interfering with grid stability.A key parameter that determines the resonance amplitude of the blade is the hydrodynamic damping ratio(HDR).However,HDR is difficult to obtain due to the complex fluid-structure interaction(FSI).Therefore,a literature review was conducted on the hydrodynamic damping characteristics of blade-like structures.The experimental and simulation methods used to identify and obtain the HDR quantitatively were described,placing emphasis on the experimental processes and simulation setups.Moreover,the accuracy and efficiency of different simulation methods were compared,and the modal work approach was recommended.The effects of key typical parameters,including flow velocity,angle of attack,gap,rotational speed,and cavitation,on the HDR were then summarized,and the suggestions on operating conditions were presented from the perspective of increasing the HDR.Subsequently,considering multiple flow parameters,several theoretical derivations and semi-empirical prediction formulas for HDR were introduced,and the accuracy and application were discussed.Based on the shortcomings of the existing research,the direction of future research was finally determined.The current work offers a clear understanding of the HDR of blade-like structures,which could improve the evaluation accuracy of flow-induced vibration in the design stage.展开更多
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
Carbon dioxide fixation technique was developed as an alternative dechlorination method of chlorobenzenes. Electrolysis of chlorobenzene was carried out in a one-compartment cell fitted with an aluminium anode and a p...Carbon dioxide fixation technique was developed as an alternative dechlorination method of chlorobenzenes. Electrolysis of chlorobenzene was carried out in a one-compartment cell fitted with an aluminium anode and a platinum cathode. Electrolysis in N, N-dimethylformamide （DMF） solution containing 0.1 M of tetrapropylammonium bromide （TPAB） at 0 ℃, 100 ml/min of CO2 flow rate and 120 mA/cm^2 of current density was found to be the optimum conditions of this electrocarboxylation, which gave 72% yield of benzoic acid from chlorobenzene. These conditions were then applied to 1,2-dichlorobenzene and 1,3-dichlorobenzene in order to convert them to their corrcsponding benzoic acids.展开更多
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
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
基金supported by the National Natural Science Foundation of China(No.81860268,and No.82201000)Ningxia Natural Science Foundation(No.2021AAC02025)+2 种基金Ningxia science and technology innovation leading talent training project(No.2020GKLRLX06 and No.2020GKLRLX11)Ningxia Medical University research project(No.XTJKF240315)Ningxia Key Research and Development Project(No.2023BEG03021 and No.2021BEB04034).
文摘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.
基金supported by the National Key Research and Development Program of China (2016YFD0300202)the National Natural Science Foundation of China (31671625, 31271669)
文摘In China, the abuse of chemical nitrogen （N） fertilizer results in decreasing N use efficiency （NUE）, wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system （IMS）. Three N rates, NN （no nitrogen application）, LN （lower N application： 270 kg N ha-1）, and CN （conventional N application： 330 kg N ha-1）, and three topdressing distances of LN （LND）, e.g., 15 cm （LND1）, 30 cm （LND2） and 45 cm （LND3） from maize rows were evaluated. At the beginning seed stage （R5）, the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant-1 and 0.14 mL h-1 plant-1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency （NAE） of IMS under CN were 308.3 kg ha-1, 28.5%, and 5.7 kg grain kg-1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15-30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.
基金National Natural Science Foundation of China,No.81272008.
文摘BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish different finite element models for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.METHODS The three-dimensional models of the normal and fractured pelvis and the five internal fixations were established using the computed tomography data of the pelvis of a living volunteer.After the vertebral body model was inserted in the way of origin matching and all cancellous bones were copied using the duplicated cancellous bone model as the subtractive entity,the Boolean operation was performed on the pelvis model to obtain the model of the complete pelvis cortical and cancellous bones.RESULTS In the standing position,the maximum stress was 46.21 MPa.In the sitting position,the sacrum bore the simulated gravity load at the upper end.When comparing the five fixations,there were no significant differences in the stress mean values among groups(sitting:P=0.9794;standing:P=0.9741).In terms of displacement,the average displacement of the internal iliac plate group was smaller than that of the spring plate group(P=0.002),and no differences were observed between the other pairs of groups(all P>0.05).In the standing position,there were no significant differences in the mean value of displacement among the groups(P=0.2985).It can be seen from the stress nephogram of the internal fixations in different positions that the stress of the internal fixation was mainly concentrated in the fracture segment.CONCLUSION There were no significant differences among the fixations for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.
文摘For an electron microscopic study of the liver,expertise and complicated,time-consuming processing of hepatic tissues and cells is needed.The interpretation of electron microscopy(EM) images requires knowledge of the liver fine structure and experience with the numerous artifacts in fixation,embedding,sectioning,contrast staining and microscopic imaging.Hence,the aim of this paper is to present a detailed summary of different methods for the preparation of hepatic cells and tissue,for the purpose of preserving long-standing expertise and to encourage new investigators and clinicians to include EM studies of liver cells and tissue in their projects.
基金Project supported by the National Natural Science Foundation of China (No. 90102012).
文摘Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.
基金Supported by Science and Technology Innovation Fund Project of Ningxia Academy of Agriculture and Forestry Sciences(NKYJ-17-18)
文摘The effects of three fixation methods( steaming,blanching and microwave fixation) on chemical composition and sensory quality of Lycium ruthenicum bud-tea were investigated.The results showed the fixation technique( the leaf weight 3 g/cm^2,the time 1.5 min,and the temperature 100 ℃) was the best,which was beneficial to the conservation of free amino acid and soluble sugar in L.ruthenicum bud-tea.The loss of chlorophyll was limited,and the score of sensory quality review was higher.
文摘Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.
文摘Rupture of the anterior cruciate ligament(ACL)is a common orthopedic injury.Various graft options are available for the reconstruction of ruptured ACL.Using the hamstring muscle as an autograft was first described in 1934,and it remains a commonly harvested graft for ACL reconstruction.Hamstring autografts can be harvested using the traditional anteromedial approach or the newer posteromedial technique.An isolated semitendinosus tendon can be used or combined with the gracilis tendon.There are numerous methods for graft fixation,such as intra-tunnel or extra-tunnel fixation.This comprehensive review discusses the different hamstring muscle harvesting techniques and graft preparation options and fixation methods.It provides a comprehensive overview for choosing the optimal surgical technique when treating patients.
文摘AIM:To explore the long term therapeutic effects of surgical treatment for isthmic spondylolisthesis.METHODS:42 cases of isthmic spondylolisthesis were analyzed retrospectively among which 13 cases underwent simple lumbar interlaminar bone implant and 29 cases underwent transpedicular fixation combined with bone implantation.Assessment was made according to JOA standards before and after treatment.RESULTS:At a 3 years of follow up assessment,the functional outcome in transpedicular fixation assessed by JOA was excellent and good in 79.3%as compared with the group without fixation in which the excellent and good result was 76.9%.The level of pain and functional disability were similar in the two groups,but fusion rate in the group with transpedicular fixation was higher than that in group without it.CONCLUSION:Surgical treatment for isthmic spondylolisthesis improves function and relieves pain.
文摘Objective: to compare the different effects of different internal fixation methods in the treatment of posterior malleolus fracture. Methods: from January to December 2020 in our hospital orthopaedic hospital for treatment of 80 patients with fracture of ankle after, for example, different internal fixation method to random grouping, average of all of these patients, line 2 pieces of 4 mm steel half thread tension screw fixed way as the control group, the "T" type three to four screws hole radius far end plate internal fixation method of patients as a team, to compare the clinical efficacy of two groups of patients and fixed strength. Results: clinical efficacy and intensity of fixation were compared between the two groups one month after operation. The results showed that there were significant differences in the total effective rate and fixation intensity between the two groups, and those in the study group were significantly higher than those in the control group (P < 0.05). Conclusion: the "T" type three-hole distal radius plate internal fixation for posterior ankle fracture surgery can significantly increase the stability of the body and help patients realize functional exercise as soon as possible. It is an excellent internal fixation method in clinical practice and is worthy of vigorously promoting and applying in clinical practice.
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
文摘BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimensional model of the femur was established from sectional computed tomography images,and an internal fixation model was established.Finite element analysis of the femur model was established,and three intertrochanteric fracture models,medial defect,lateral defect,and medial-lateral defects,were simulated.Displacement and stress distribution after fixation with a proximal femoral anti-rotation intramedullary nail(PFNA),integrated dual-screw fixation(ITN),PFNA+wire,PFNA+plate,and PFNA+wire+plate were compared during daily activities.RESULTS The maximum displacement and stress of PFNA and ITN were 3.51 mm/473 MPa and 2.80 mm/588 MPa for medial defects;2.55 mm/288 MPa and 2.10 mm/307 MPa for lateral defects;and 3.84 mm/653 MPa and 3.44 mm/641 MPa for mediallateral defects,respectively.For medial-lateral defects,reconstructing the medial side alone changed the maximum displacement and stress to 2.79 mm/515 MPa;reconstructing the lateral side changed them to 3.72 mm/608 MPa,when both sides were reconstructed,they changed to 2.42 mm/309 MPa.CONCLUSION For medial defects,intramedullary fixation would allow early low-intensity rehabilitation exercise,and ITN rather than PFNA reduces the risk of varus and cut-out;for lateral wall defects or weakness,intram-edullary fixation allows higher-intensity rehabilitation exercise,and ITN reduces the risk of varus.For both medial and lateral defects,intramedullary fixation alone will not allow early functional exercise,but locating lateral or medial reconstruction will.For defects in both the inner and outer sides,if reconstruction cannot be completed,ITN is more stable.
基金supported by the National Natural Science Foundation of China(12172023).
文摘The separation-of-variable(SOV)methods,such as the improved SOV method,the variational SOV method,and the extended SOV method,have been proposed by the present authors and coworkers to obtain the closed-form analytical solutions for free vibration and eigenbuckling of rectangular plates and circular cylindrical shells.By taking the free vibration of rectangular thin plates as an example,this work presents the theoretical framework of the SOV methods in an instructive way,and the bisection–based solution procedures for a group of nonlinear eigenvalue equations.Besides,the explicit equations of nodal lines of the SOV methods are presented,and the relations of nodal line patterns and frequency orders are investigated.It is concluded that the highly accurate SOV methods have the same accuracy for all frequencies,the mode shapes about repeated frequencies can also be precisely captured,and the SOV methods do not have the problem of missing roots as well.
基金funded by the National Natural Science Foundation of China(No.41962016)the Natural Science Foundation of NingXia(Nos.2023AAC02023,2023A1218,and 2021AAC02006).
文摘Soil improvement is one of the most important issues in geotechnical engineering practice.The wide application of traditional improvement techniques(cement/chemical materials)are limited due to damage ecological en-vironment and intensify carbon emissions.However,the use of microbially induced calcium carbonate pre-cipitation(MICP)to obtain bio-cement is a novel technique with the potential to induce soil stability,providing a low-carbon,environment-friendly,and sustainable integrated solution for some geotechnical engineering pro-blems in the environment.This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy.It systematically summarizes and overviews the mineralization mechanism,influ-encing factors,improved methods,engineering characteristics,and current field application status of the MICP.Additionally,it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement.This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand.Furthermore,we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future.The current review purports to provide insights for engineers and interdisciplinary researchers,and guidance for future engineering applications.
文摘In order to solve the problem of the variable coefficient ordinary differen-tial equation on the bounded domain,the Lagrange interpolation method is used to approximate the exact solution of the equation,and the error between the numerical solution and the exact solution is obtained,and then compared with the error formed by the difference method,it is concluded that the Lagrange interpolation method is more effective in solving the variable coefficient ordinary differential equation.
基金Supported by the National Natural Science Foundation of China(Nos.52222904 and 52309117)China Postdoctoral Science Foundation(Nos.2022TQ0168 and 2023M731895).
文摘Ocean energy has progressively gained considerable interest due to its sufficient potential to meet the world’s energy demand,and the blade is the core component in electricity generation from the ocean current.However,the widened hydraulic excitation frequency may satisfy the blade resonance due to the time variation in the velocity and angle of attack of the ocean current,even resulting in blade fatigue and destructively interfering with grid stability.A key parameter that determines the resonance amplitude of the blade is the hydrodynamic damping ratio(HDR).However,HDR is difficult to obtain due to the complex fluid-structure interaction(FSI).Therefore,a literature review was conducted on the hydrodynamic damping characteristics of blade-like structures.The experimental and simulation methods used to identify and obtain the HDR quantitatively were described,placing emphasis on the experimental processes and simulation setups.Moreover,the accuracy and efficiency of different simulation methods were compared,and the modal work approach was recommended.The effects of key typical parameters,including flow velocity,angle of attack,gap,rotational speed,and cavitation,on the HDR were then summarized,and the suggestions on operating conditions were presented from the perspective of increasing the HDR.Subsequently,considering multiple flow parameters,several theoretical derivations and semi-empirical prediction formulas for HDR were introduced,and the accuracy and application were discussed.Based on the shortcomings of the existing research,the direction of future research was finally determined.The current work offers a clear understanding of the HDR of blade-like structures,which could improve the evaluation accuracy of flow-induced vibration in the design stage.
基金supported by the National Natural Science Foundation of China(52164028,52274297)the Start-up Research Foundation of Hainan University(KYQD(ZR)20008,KYQD(ZR)21125,KYQD(ZR)23169))+1 种基金Collaborative Innovation Center of Marine Science and Technology of Hainan University(XTCX2022HYC14)Innovative Research Project for Postgraduate Students in Hainan Province(Qhyb2024-95).
文摘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.
文摘Carbon dioxide fixation technique was developed as an alternative dechlorination method of chlorobenzenes. Electrolysis of chlorobenzene was carried out in a one-compartment cell fitted with an aluminium anode and a platinum cathode. Electrolysis in N, N-dimethylformamide （DMF） solution containing 0.1 M of tetrapropylammonium bromide （TPAB） at 0 ℃, 100 ml/min of CO2 flow rate and 120 mA/cm^2 of current density was found to be the optimum conditions of this electrocarboxylation, which gave 72% yield of benzoic acid from chlorobenzene. These conditions were then applied to 1,2-dichlorobenzene and 1,3-dichlorobenzene in order to convert them to their corrcsponding benzoic acids.
基金supported by the National Natural Science Foundation of China(No.32160142)Guangxi Natural Science Foundation(No.2023GXNSFDA026034)+3 种基金State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKLCUSAb202302)to H.W.,the National Natural Science Foundation of China(No.32460062)to Y.L.,and 1+9 Leading the Charge with Open Competition'project of Sichuan Academy of Agricultural Sciences(1+9KJGG010)Fruit tree breeding project in Sichuan Province(2021YFYZ0023)to H.X.
文摘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.
基金funded by the European Union-NextGenerationEU under the Italian Ministry of University and Research(MUR)National Innovation Ecosystem grant ECS00000041-VITALITYThe University of Perugia is acknowledged for financial support to the university project“Fondo Ricerca di Ateneo,edizione 2021”and“Fondo Ricerca di Ateneo,edizione 2022”CSGI(Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase)for the support.
文摘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.
