The paper concerns the problem on statistical description of the turbulent velocity pulsations by using the method of characteristic functional. The equations for velocity covariance and Green’s function, which descr...The paper concerns the problem on statistical description of the turbulent velocity pulsations by using the method of characteristic functional. The equations for velocity covariance and Green’s function, which describes an average velocity response to external force action, have been obtained. For the nonlinear term in the equation for velocity covariance, it has been obtained an exact representation in the form of two terms, which can be treated as describing a momentum transport due to turbulent viscosity and action of effective random forces (within the framework of traditional phenomenological description, the turbulent viscosity is only accounted for). Using a low perturbation theory approximation for high statistical moments, a scheme of closuring the chain of equations for statistical moments is proposed. As the result, we come to a closed set of equations for velocity covariance and Green’s function, the solution to which corresponds to summing up a certain infinite subsequence of total perturbation series.展开更多
The models constructed by particle flow simulation method can effectively simulate the heterogeneous substance characteristics and failure behaviors of rocks.However,existing contact models overlook the rock cracks,an...The models constructed by particle flow simulation method can effectively simulate the heterogeneous substance characteristics and failure behaviors of rocks.However,existing contact models overlook the rock cracks,and the various simulation methods that do consider cracks still exhibit certain limitations.In this paper,based on Flat-Joint model and Linear Parallel Bond model,a crack contact model considering linked substance in the crack is proposed by splitting the crack contact into two portions:linked portion and unlinked portion for calculation.The new contact model considers the influence of crack closure on the contact force-displacement law.And a better compressive tensile strength ratio(UCS/T)was obtained by limiting the failure of the contact bond to be solely controlled by the contact force and moment of the linked portion.Then,by employing the FISH Model tool within the Particle Flow Code,the contact model was constructed and verified through contact force–displacement experiments and loading-unloading tests with cracked model.Finally,the contact model was tested through simulations of rock mechanics experiments.The results indicate that the contact model can effectively simulate the axial and lateral strain laws of rocks simultaneously and has a relatively good reproduction of the bi-modularity of rocks.展开更多
The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carri...The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.展开更多
Understanding the diffusion mechanisms of indium(In)in ZnS minerals can clarify the kinetic processes governing its migration,enrichment,or depletion in these typical In-host minerals,thereby establishing a theoretica...Understanding the diffusion mechanisms of indium(In)in ZnS minerals can clarify the kinetic processes governing its migration,enrichment,or depletion in these typical In-host minerals,thereby establishing a theoretical foundation for the exploration of high-grade In deposits.This study investigates sphalerite and wurtzite to identify stable In incorporation sites and diffusion pathways,and systematically calculates In transport properties in two types of ZnS minerals using first-principles calculations combined with the climbing image-nudged elastic band(CI-NEB)method.The results demonstrate that structural anisotropy significantly governs In diffusion characteristics,with wurtzite exhibiting stronger directiondependent diffusion behavior and superior In retention capacity compared to sphalerite.Across the 0−10 GPa pressure range,In diffusion in wurtzite shows markedly higher anisotropy(2−3 orders of magnitude greater than in sphalerite)and consistently lower diffusion rates.Furthermore,closure temperature calculations reveal spatial heterogeneity,with the[111]direction in sphalerite(about 65 K higher than[110]direction)and the[001]direction in wurtzite(about 100 K higher than[100]direction)displaying elevated closure thresholds.Overall,wurtzite achieves higher closure temperatures than sphalerite.These computational findings indicate that wurtzite exhibits stronger In retention capabilities than sphalerite,suggesting its potential as a critical host mineral for In.These insights provide valuable implications for understanding In geochemical cycling and offer some guidance for mineral exploration and ore genesis studies.展开更多
AIM:To study the relationship between ultrasound biomicroscopy(UBM)and Lenstar when measuring anterior chamber depth(ACD)in eyes with shallow anterior chamber,and the necessity of conducting both examinations.METHODS:...AIM:To study the relationship between ultrasound biomicroscopy(UBM)and Lenstar when measuring anterior chamber depth(ACD)in eyes with shallow anterior chamber,and the necessity of conducting both examinations.METHODS:This is a retrospective observational study including 56 acute primary angle closure(APAC)eyes and 47 primary angle closure suspect(PACS)eyes with shallow ACD.ACD value measured by Lenstar and UBM were documented.The Bland-Altman plots were examined separately in all included eyes,APAC eyes and PACS eyes,for the assessment of agreement between two measurements.The agreement was compared across different population by evaluating mean difference,width of 95%limit of agreement(LoA)and the presence of proportional bias or outliers in Bland-Altman plots.R E S U LT S:The average ACD in APAC eyes(1.71±0.23 mm)was significantly smaller than that in PACS eyes(1.79±0.25 mm,P=0.038).Bland-Altman plots of both APAC eyes and PACS eyes showed small mean difference without the presence of proportional bias.However,compared with PACS eyes,the Bland-Altman plot of APAC eyes had wider 95%LoA and more outliers outside the 95%LoA.CONCLUSION:Despite the small ACD values,the two methods in measuring ACD,Lenstar and UBM,demonstrate substantial consistency when measuring PACS eyes.However,for the APAC population,the agreement might be limited,and thus the measured values should be interpreted with caution.展开更多
During upward horizontal stratified backfill mining,stable backfill is essential for cap and sill pillar recovery.Currently,the primary method for calculating the required strength of backfill is the generalized three...During upward horizontal stratified backfill mining,stable backfill is essential for cap and sill pillar recovery.Currently,the primary method for calculating the required strength of backfill is the generalized three-dimensional(3 D)vertical stress model,which ignores the effect of mine depth,failing to obtain the vertical stress at different positions along stope length.Therefore,this paper develops and validates an improved 3 D model solution through numerical simulation in Rhino-FLAC^(3D),and examines the stress state and stability of backfill under different conditions.The results show that the improved model can accurately calculate the vertical stress at different mine depths and positions along stope length.The error rates between the results of the improved model and numerical simulation are below 4%,indicating high reliability and applicability.The maximum vertical stress(σ_(zz,max))in backfill is positively correlated with the degree of rock-backfill closure,which is enhanced by mine depth and elastic modulus of backfill,while weakened by stope width and inclination,backfill friction angle,and elastic modulus of rock mass.Theσ_(zz,max)reaches its peak when the stope length is 150 m,whileσ_(zz,max)is insensitive to changes in rock-backfill interface parameters.In all cases,the backfill stability can be improved by reducingσ_(zz,max).The results provide theoretical guidance for the backfill strength design and the safe and efficient recovery of ore pillars in deep mining.展开更多
Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects ...Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects the quality.The hormone abscisic acid(ABA)plays a crucial role in plant responses to abiotic stresses.Previous studies showed that exogenous ABA promotes floret closure,although the molecular mechanisms and effects of endogenous ABA on floret closure remain unknown.In this study,the effect of endogenous ABA on floret closure and the molecular mechanism by which ABA promotes floret closure through sugar transporters were investigated by changing the expression levels of OsNCED3 and OsPYL1 in rice.The results showed that overexpression(OE)-OsNCED3increased the endogenous ABA level of florets.Florets closed 5.91 min earlier and OsNCED3 gene knockout line delayed the closure of florets by 5.08 min compared with the wild type.In addition,OsPYL1 regulated the endogenous ABA content and changed the sensitivity to ABA such that the floret closure times for OE and CRISPR-Cas9(CR)were 9.84 min earlier and 12.78 min later,respectively,resulting in an increase in the split husk rate to 15.4%.The gene expression levels of some sugar transporters(STs)changed.The OsPYL1 and OsSWEET4proteins could interact on the cell membrane.These results indicate that ABA promotes the closure of rice florets and the enhanced sensitivity to ABA promotes this effect even more.The molecular mechanism is mainly related to downstream sugar transporters that respond to the ABA signaling pathway,especially OsSWEET4.展开更多
Dear Editor,X-linked retinoschisis(XLRS)is a rare X-linked recessive disorder predominantly afflicting young males.The schisis of the retinal layers is a result of deleterious mutations in the RS1 gene.Insufficient ep...Dear Editor,X-linked retinoschisis(XLRS)is a rare X-linked recessive disorder predominantly afflicting young males.The schisis of the retinal layers is a result of deleterious mutations in the RS1 gene.Insufficient epidemiological data has caused significant variation in reported global prevalence,with estimates fluctuating between 1 in 5000 and 1 in 30000 individuals[1].A large follow-up multicenter study recently published has yielded noteworthy findings concerning the phenotypic spectrum,long-term natural history,and genotype of XLRS.The investigation revealed a significant variability in visual function and disease progression,with particular variants of the RS1 gene displaying diverse phenotypic expressions,suggesting the intricate genetic basis underlying this disorder[2].The range of visual impairments associated with XLRS is extensive,varying from minor to severe.This condition is also characterized by specific retinal abnormalities,including radial streaks emanating from a divided central fovea,schisis affecting the inner layers of the retina in peripheral areas,and a diminished amplitude ratio of b-to a-wave,or even an electronegative electroretinography(ERG)[3].At their initial consultation,the majority of individuals with XLRS exhibit visual acuity(VA)levels between 20/60 and 20/120.However,there is a significant diversity in the condition’s presentation and progression,even among relatives,with VA levels spanning from near-normal to complete loss of sight[4-5].While vision tends to be reasonably consistent over several years for those with XLRS,there is documentation of a more rapid decline in later adulthood,specifically during the fourth and fifth decades,due to central retinal degeneration[5-7].Moreover,those with XLRS face an elevated risk for serious visual issues,such as retinal detachment,vitreous hemorrhages,and neovascular glaucoma[4].Female carriers could be found with slightly abnormal retinal changes without clinical symptoms[5].Even within the same family,the manifestation and progression of the condition can vary greatly,with individuals experiencing anything from nearly normal vision to complete loss of sight[8-9].Earlier investigations have revealed that retinoschisisrelated cystoid degeneration can impact multiple layers of the retina,beginning at the retinal nerve fiber zone and continuing to the nuclear stratum,with considerable fluctuation in the severity of the schisis[10-13].展开更多
Objective: To evaluate the efficacy of endovenous radiofrequency ablation (RFA) and laser ablation (EVLA) in the treatment of superficial varicose veins of the lower extremities. Methods: Seventy-eight patients with s...Objective: To evaluate the efficacy of endovenous radiofrequency ablation (RFA) and laser ablation (EVLA) in the treatment of superficial varicose veins of the lower extremities. Methods: Seventy-eight patients with superficial varicose veins treated at a hospital between April 2022 and May 2023 were selected and divided into a radiofrequency ablation group (RFA group;39 cases) and a laser ablation group (EVLA group;39 cases) based on the treatment method. Operation time, postoperative recovery duration, venous clinical severity score (VCSS) changes, complication rates, closure rates, and recurrence rates were compared between the groups at 1 month, 3 months, and 12 months postoperatively. The postoperative therapeutic outcomes were comprehensively evaluated. Results: No significant differences in age, gender, disease grade, or disease course were observed between the groups (P > 0.05). The superficial varicose vein closure rate was 100% in both groups at 1 and 3 months postoperatively. At 12 months, the closure rate was 94.87% in the RFA group and 97.43% in the EVLA group, with no statistically significant difference (P > 0.05). No significant differences were observed in VCSS changes or complication incidence between the groups (P > 0.05). Conclusion: Radiofrequency ablation and laser ablation demonstrate comparable efficacy and safety in the treatment of superficial varicose veins of the lower extremities.展开更多
Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers sho...Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers should carry out all production activities under the cemented backfill roof or sill mat instead of a highly fractured and unstable rock roof or a strong rock roof with a high potential of rockburst.Therefore,the stability and required strength of the sill mat are critical issues for mining engineers.In 1991,Mitchell considered that sill mat could fail by caving,sliding,rotation,and flexure.Mitchell also proposed an analytical solution to determine the minimum required strength of the sill mat for each type of failure based on two stiff or immobile rock walls.However,recent publications using numerical modeling and field measurements indicate that the compressive stresses in the sill mat induced by rock wall closure due to a stope excavation beneath the sill mat can be significant.It is thus highly necessary to investigate the required strength of the sill mat by considering rock wall closure.In this study,the crushing failure of sill mat due to rock wall closure generated by underground excavation and a new failure mode called"crushing and caving”is revealed by numerical modeling.An analytical solution corresponding to each failure mode is then developed to estimate the minimum required cohesion(cmin)of the sill mat.A criterion is also proposed to determine if the sill mat fails by crushing or crushing-and-caving failure.The proposed analytical solution does not involve any correction coefficients.The validity of the proposed analytical solution is demonstrated by numerical modeling.The proposed analytical solution can thus be employed to predict the cmin of sill mat subjected to wall closure generated by underlying stope excavation.展开更多
Congenital atrial septal defect(ASD)with severe scoliosis is a rare compound malformation inchildren.Severe sco liosis should be corrected as soon as possible.The growth rod is suitable for patients withearly scoliosi...Congenital atrial septal defect(ASD)with severe scoliosis is a rare compound malformation inchildren.Severe sco liosis should be corrected as soon as possible.The growth rod is suitable for patients withearly scoliosis and obvious scoliosis under 10 years old.However,the fluoroscopic radiopaque of titaniumalloy plate will inevitably partly make the operative field of interventional occlusion blind.We presenta7-year-old Chinese girl with ASD and scoliosis who underwent spinal correction with a dual-growthrod.In this case,we performed transcatheter closure of ASD solely under the guidance of transthoracicechocardiography.Transthoracic echocardiography(TTE)has been reported as efficacious and safe forassessment and guidance of ASD occlusion.For patients with visual field occlusion under fluoroscopy,theapplication of TTE is efficacious and safe for assessmnent and guidance of ASD occlusion.展开更多
In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability o...In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability of the fracture.To evaluate this relationship,we numerically generated self-affine fractures reproducing the scaling relationship of the power spectral density(PSD)of the measured fracture surfaces.The fractures were then subjected to a uniform and stepwise increase in normal stress.A fast Fourier transform(FFT)-based elastic contact model was used to simulate the fracture closure.The evolution of fracture contact area,fracture closure,and fracture normal stiffness were determined throughout the whole process.In addition,the fracture permeability at each step was calculated by the local cubic law(LCL).The influences of roughness exponent and correlation length on the fracture hydraulic and mechanical behaviors were investigated.Based on the power law of normal stiffness versus normal stress,the corrected cubic law and the linear relationship between fracture closure and mechanical aperture were obtained from numerical modeling of a set of fractures.Then,we derived a fracture normal stiffness-permeability equation which incorporates fracture geometric parameters such as the root-mean-square(RMS),roughness exponent,and correlation length,which can describe the fracture flow under an effective medium regime and a percolation regime.Finally,we interpreted the flow transition behavior from the effective medium regime to the percolation regime during fracture closure with the established stiffness-permeability function.展开更多
BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the ab...BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the abdominal cavity,abdominal closure using traditional vertical interrupted suturing is associated with a higher incidence of wound infections.For patients undergoing ileostomy closure,selecting an appropriate suturing method for the skin incision at the stoma site is crucial for improving patient prognosis.AIM To investigate the impact of three different skin suturing methods at the ileostomy closure site on patient prognosis.METHODS Thirty patients who underwent ileostomy closure at the Affiliated Hospital of Qinghai University between January 2024 and October 2024 were selected based on inclusion and exclusion criteria.The patients were divided into three groups:The purse-string suture group,the cross-suture group,and the vertical interrupted suture group,with 10 cases in each group.The purse-string suture group,cross-suture group,and vertical interrupted suture group used purse-string,cross,and vertical interrupted suturing methods,respectively,for the skin incision at the ileostomy closure site.RESULTS There were no statistically significant differences among the three groups in terms of operative time,intraoperative blood loss,time to resume liquid diet,time to first bowel movement,postoperative hospital stay,hospitalization costs,or levels of white blood cell count,hemoglobin,and albumin on the third postoperative day(P>0.05).Nevertheless,significant differences(P<0.05)were observed in incision suture removal time,wound healing time,C-reactive protein levels on the third postoperative day,visual analog scale pain scores during the first three postoperative days,and the incidence of surgical site infection.Overall,the therapeutic outcomes of the pursestring suture group and the cross-suture group were superior to the vertical interrupted suture group.CONCLUSION Using purse-string or cross-suturing methods for skin incision at the ileostomy closure site can shorten wound healing and suture removal times,reduce surgical site infection incidence and postoperative inflammatory response,alleviate incision pain,and promote rapid postoperative recovery.展开更多
Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree spec...Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree species in boreal Eurasia,calling for a comprehensive understanding of how larch adapts to changes in both rainfall and snowfall by adjusting carbon-water physiology.Here,we conducted a short-term rainfall(−60% ambient rainfall;three-year)and snowfall(−73% ambient snowfall;two-year)exclusions experiment in Larix gmelinii forest in northeastern China,and aimed to explore the responses of hydraulic(leaf pressure-volume traits,leaf and branch hydraulic conductivity and embolism resistance),stomatal(stomatal closure point and stomatal safety margin),and economic(photosynthetic rate,nutrient and non-structural carbohydrates contents)traits to rainfall and snowfall reductions.Despite the weak alternation of leaf and branch hydraulic traits,both rainfall and snowfall reductions significantly led to early stomatal closure and increased stomatal safety margins(the difference between stomatal closure point and xylem embolism threshold,describing drought resistance by merging both hydraulic and stomatal strategies).Reductions in rainfall and snowfall induced water or/and low-temperature stress,resulting in more conservative leaf economic traits,including a reduced photosynthetic rate,lower leaf nitrogen concentration,and higher leaf density.In addition,larch responded to reductions in rainfall and snowfall by up-regulating non-structural carbohydrates in the xylem,which helps repair embolism or lower the freezing point acting as osmolytes.Overall,our findings reveal that larch could adapt to the drought and snowpack reduction by strict stomatal regulation and investing non-structural carbohydrates in embolism repairing,at the cost of carbon assimilation.展开更多
In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs...In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs.A critical issue is to determine the minimum required strength of the sill mat to ensure a safe and cost-effective design.Until now,Mitchell’s analytical solution is the only available option,considering two stiff and immobile rock walls.Unavoidable rock wall closure associated with stope excavation below the sill mat was neglected.This,along with other undefined parameters,explains why Mitchell’s solution is rarely used in sill mat design.A new analytical solution for determining the minimum required strength of the sill mat accounting for wall closure is necessary.In this study,a closed-form analytical solution for estimating rock wall closure generated by stope excavation below a sill mat is developed by using Salamon’s and Flamant’s models.The proposed analytical solution does not contain any coefficients of correction or calibration.Despite several assumptions(or somewhat of oversimplifications)necessary to render a simple analytical solution possible,good agreements are obtained between the rock wall closures predicted by applying the proposed analytical solution and those obtained numerically with FLAC3D for many cases with arbitrarily chosen geometrical and material parameters.The proposed analytical solution is therefore validated and can be used to evaluate the rock wall closure generated by stope excavation below a sill mat.展开更多
BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli includi...BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli including stroke,and decompression sickness.We aimed to study the trends in utilization and reimbursements of transcatheter ASD/PFO closure devices.AIM To analyze trends in utilization and Medicare reimbursements for transcatheter ASD/PFO closure procedures from 2013 to 2022.METHODS A query of administrative data on United States Medicare beneficiaries undergoing transcatheter ASD/PFO was conducted from 2013 to 2022 using the Centers for Medicare and Medicaid Services Part B National Summary Data File.Inflation adjustments were made using the 2023 Consumer Price Index.Trend analysis was quantified using growth rate and simple linear regression calculations.All analyses were performed using Microsoft Excel 16.77.1(2023).RESULTS The annual number of transcatheter ASD/PFO closure procedures increased by 81%since 2013,with an average yearly growth rate of 44%cases per year(P<0.001).Annual Medicare reimbursements for transcatheter ASD/PFO therapies mirrored the annual procedure trends.The per-case reimbursements decreased by 18%,i.e.,$1128.80 in 2013 and$770.21 in 2022(P<0.001).There was a significant drop in the number of procedures in the year 2020,which correlates to the onset of the coronavirus disease 2019 pandemic,followed by a sharp uptick in the number of cases in 2021 and 2022.CONCLUSION Medicare utilization of transcatheter ASD/PFO closure therapies has grown significantly in procedural volume from 2013 to 2022.However,this has been accompanied by a decrease in per-case reimbursements.展开更多
On 30 September 2024,the UK shuttered its last remaining coal-fired power plant[1].The closure marks a historic milestone,the end of 142 years of coal fueled prosperity.The country opened the world’s first plant to s...On 30 September 2024,the UK shuttered its last remaining coal-fired power plant[1].The closure marks a historic milestone,the end of 142 years of coal fueled prosperity.The country opened the world’s first plant to supply electric streetlamps in 1882,spark-ing a global energy revolution that has led to today’s nearly univer-sally electrified world.展开更多
This paper comprehensively explores the technical principles and application practice of Sainaoning absorbable dural sealant medical adhesive in dural closure.It elaborates on the research and development background o...This paper comprehensively explores the technical principles and application practice of Sainaoning absorbable dural sealant medical adhesive in dural closure.It elaborates on the research and development background of Sainaoning,analyzes its composition,action mechanism,and product characteristics in detail,and presents the results of pre-clinical and clinical studies.The application of Sainaoning in different craniotomy surgeries is discussed,and its effectiveness and safety are evaluated.The paper also analyzes the challenges in its application and proposes corresponding countermeasures,aiming to provide a comprehensive understanding and reference for the clinical use and further development of Sainaoning.展开更多
BACKGROUND Gastric ulcer perforation is a critical condition that can lead to significant morbidity and mortality if not promptly addressed.It is often the result of chronic peptic ulcer disease,which is characterized...BACKGROUND Gastric ulcer perforation is a critical condition that can lead to significant morbidity and mortality if not promptly addressed.It is often the result of chronic peptic ulcer disease,which is characterized by a breach in the gastric wall due to ulceration.Surgical intervention is essential for managing this life-threatening complication.However,the optimal surgical technique remains debatable among clinicians.Various methods have been employed,including simple closure,omental patch repair,and partial gastrectomy,each with distinct advantages and disadvantages.Understanding the comparative efficacy and postoperative outcomes of these techniques is crucial for improving patient care and surgical decision-making.This study addresses the need for a comprehensive analysis in this area.AIM To compare the efficacy and postoperative complications of different surgical methods for the treatment of gastric ulcer perforation.METHODS A retrospective analysis was conducted on 120 patients who underwent surgery for gastric ulcer perforation between September 2020 and June 2023.The patients were divided into three groups based on the surgical method:Simple closure,omental patch repair,and partial gastrectomy.The primary outcomes were the operative success rate and incidence of postoperative complications.Secondary outcomes included the length of hospital stay,recovery time,and long-term quality of life.RESULTS The operative success rates for simple closure,omental patch repair,and partial gastrectomy were 92.5%,95%,and 97.5%,respectively.Postoperative complications occurred in 20%,15%,and 17.5%of patients in each group,respectively.The partial gastrectomy group showed a significantly longer operative time(P<0.001)but the lowest rate of ulcer recurrence(2.5%,P<0.05).The omental patch repair group demonstrated the shortest hospital stay(mean 7.2 days,P<0.05)and fastest recovery time.CONCLUSION While all three surgical methods showed high success rates,omental patch repair demonstrated the best overall outcomes,with a balance of high efficacy,low complication rates,and shorter recovery time.However,the choice of the surgical method should be tailored to individual patient factors and the surgeon’s expertise.展开更多
BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),comple...BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),complete endoscopic excision is the preferred treatment.Endoscopic full-thickness resection(EFTR)has proven to be an effective approach.AIM To evaluate the efficacy of the interrupted closure technique compared to the traditional closure technique in EFTR for gastric SELs.METHODS This single-center,prospective,randomized controlled trial was conducted at a tertiary hospital from September 2023 to September 2024.A total of 90 patients who underwent EFTR for gastric SELs were randomly allocated to either the interrupted closure group(n=44)or the traditional closure group(n=46).RESULTS All patients had complete resection and wound closure without any severe postoperative complications.The incidence of intraoperative gas-related complications was significantly lower in the interrupted closure group than in the traditional closure group(2.27%vs 26.09%,P=0.001),demonstrating interrupted closure technique can reduce the incidence of gas-related issues.Statistical analysis revealed that the incidence of postoperative infection was significantly lower in the experimental group than in the control group(15.91%vs 41.30%,P=0.008).Additionally,the median duration of antibiotic use was lower in the experimental group(3.5 days vs 5 days,P=0.013).Abdominal pain levels on postoperative days 1 and 4 were also lower in the experimental group compared to the control group(P<0.001).CONCLUSION The interrupted closure technique in EFTR for treating gastric SELs is safe and effective,reducing the incidence of intraoperative gas complications and postoperative infections.展开更多
文摘The paper concerns the problem on statistical description of the turbulent velocity pulsations by using the method of characteristic functional. The equations for velocity covariance and Green’s function, which describes an average velocity response to external force action, have been obtained. For the nonlinear term in the equation for velocity covariance, it has been obtained an exact representation in the form of two terms, which can be treated as describing a momentum transport due to turbulent viscosity and action of effective random forces (within the framework of traditional phenomenological description, the turbulent viscosity is only accounted for). Using a low perturbation theory approximation for high statistical moments, a scheme of closuring the chain of equations for statistical moments is proposed. As the result, we come to a closed set of equations for velocity covariance and Green’s function, the solution to which corresponds to summing up a certain infinite subsequence of total perturbation series.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.ZD2021E006)the National Natural Science Foundation of China(Nos.52174075 and 52074110).
文摘The models constructed by particle flow simulation method can effectively simulate the heterogeneous substance characteristics and failure behaviors of rocks.However,existing contact models overlook the rock cracks,and the various simulation methods that do consider cracks still exhibit certain limitations.In this paper,based on Flat-Joint model and Linear Parallel Bond model,a crack contact model considering linked substance in the crack is proposed by splitting the crack contact into two portions:linked portion and unlinked portion for calculation.The new contact model considers the influence of crack closure on the contact force-displacement law.And a better compressive tensile strength ratio(UCS/T)was obtained by limiting the failure of the contact bond to be solely controlled by the contact force and moment of the linked portion.Then,by employing the FISH Model tool within the Particle Flow Code,the contact model was constructed and verified through contact force–displacement experiments and loading-unloading tests with cracked model.Finally,the contact model was tested through simulations of rock mechanics experiments.The results indicate that the contact model can effectively simulate the axial and lateral strain laws of rocks simultaneously and has a relatively good reproduction of the bi-modularity of rocks.
基金support from National Natural Science Foundation of China(NSFC,Grant numbers U22A20185,U21A20128,52175302 and 52305353)Aeronautical Science Foundation(ASFC-20230036077001)Fundamental Research Funds for the Central Universities(2022FRFK060009,HIT.DZI1.2023012).
文摘The excellent irradiation resistance,high strength and plasticity exhibited by high-entropy alloys(HEAs)make it candidate for engin-eering applications.Diffusion bonding of Al_(0.3)CoCrFeNi single-phase HEAs was carried out using electric-assisted diffusion bonding(EADB),and the effect of bonding temperature on the evolution of the interfacial microstructure and the mechanical properties was investigated.The results indicate that as the bonding temperature increases,the pores at the interface gradually decrease in size and undergo closure.The electric current significantly promotes the pore closure mechanism dominated by plastic deformation at the diffusion interface and promotes the recrystallisation behavior at the interface,and the fracture mode changes from intergranular fracture at the interface to jagged fracture along the grains spanning the weld parent material.Due to the activation effect of EADB,higher-strength diffusion bonding of high-entropy alloys can be achieved at the same temperature compared with the conventional hot-pressure diffusion bonding(HPDB)process.
基金National Natural Science Foundation of China(41573121,42174115,42394114)Open Fundation of the United Laboratory of High-Pressure Physics and Earthquake Science(2019HPPES06)。
文摘Understanding the diffusion mechanisms of indium(In)in ZnS minerals can clarify the kinetic processes governing its migration,enrichment,or depletion in these typical In-host minerals,thereby establishing a theoretical foundation for the exploration of high-grade In deposits.This study investigates sphalerite and wurtzite to identify stable In incorporation sites and diffusion pathways,and systematically calculates In transport properties in two types of ZnS minerals using first-principles calculations combined with the climbing image-nudged elastic band(CI-NEB)method.The results demonstrate that structural anisotropy significantly governs In diffusion characteristics,with wurtzite exhibiting stronger directiondependent diffusion behavior and superior In retention capacity compared to sphalerite.Across the 0−10 GPa pressure range,In diffusion in wurtzite shows markedly higher anisotropy(2−3 orders of magnitude greater than in sphalerite)and consistently lower diffusion rates.Furthermore,closure temperature calculations reveal spatial heterogeneity,with the[111]direction in sphalerite(about 65 K higher than[110]direction)and the[001]direction in wurtzite(about 100 K higher than[100]direction)displaying elevated closure thresholds.Overall,wurtzite achieves higher closure temperatures than sphalerite.These computational findings indicate that wurtzite exhibits stronger In retention capabilities than sphalerite,suggesting its potential as a critical host mineral for In.These insights provide valuable implications for understanding In geochemical cycling and offer some guidance for mineral exploration and ore genesis studies.
基金Supported by the Surface Project of National Natural Science Foundation of China(No.82070957)the Shandong Medical and Health Technology Development Project(No.202107021077).
文摘AIM:To study the relationship between ultrasound biomicroscopy(UBM)and Lenstar when measuring anterior chamber depth(ACD)in eyes with shallow anterior chamber,and the necessity of conducting both examinations.METHODS:This is a retrospective observational study including 56 acute primary angle closure(APAC)eyes and 47 primary angle closure suspect(PACS)eyes with shallow ACD.ACD value measured by Lenstar and UBM were documented.The Bland-Altman plots were examined separately in all included eyes,APAC eyes and PACS eyes,for the assessment of agreement between two measurements.The agreement was compared across different population by evaluating mean difference,width of 95%limit of agreement(LoA)and the presence of proportional bias or outliers in Bland-Altman plots.R E S U LT S:The average ACD in APAC eyes(1.71±0.23 mm)was significantly smaller than that in PACS eyes(1.79±0.25 mm,P=0.038).Bland-Altman plots of both APAC eyes and PACS eyes showed small mean difference without the presence of proportional bias.However,compared with PACS eyes,the Bland-Altman plot of APAC eyes had wider 95%LoA and more outliers outside the 95%LoA.CONCLUSION:Despite the small ACD values,the two methods in measuring ACD,Lenstar and UBM,demonstrate substantial consistency when measuring PACS eyes.However,for the APAC population,the agreement might be limited,and thus the measured values should be interpreted with caution.
基金Project(2024ZD1003704)supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project,ChinaProjects(51834001,52130404)supported by the National Natural Science Foundation of China。
文摘During upward horizontal stratified backfill mining,stable backfill is essential for cap and sill pillar recovery.Currently,the primary method for calculating the required strength of backfill is the generalized three-dimensional(3 D)vertical stress model,which ignores the effect of mine depth,failing to obtain the vertical stress at different positions along stope length.Therefore,this paper develops and validates an improved 3 D model solution through numerical simulation in Rhino-FLAC^(3D),and examines the stress state and stability of backfill under different conditions.The results show that the improved model can accurately calculate the vertical stress at different mine depths and positions along stope length.The error rates between the results of the improved model and numerical simulation are below 4%,indicating high reliability and applicability.The maximum vertical stress(σ_(zz,max))in backfill is positively correlated with the degree of rock-backfill closure,which is enhanced by mine depth and elastic modulus of backfill,while weakened by stope width and inclination,backfill friction angle,and elastic modulus of rock mass.Theσ_(zz,max)reaches its peak when the stope length is 150 m,whileσ_(zz,max)is insensitive to changes in rock-backfill interface parameters.In all cases,the backfill stability can be improved by reducingσ_(zz,max).The results provide theoretical guidance for the backfill strength design and the safe and efficient recovery of ore pillars in deep mining.
基金supported by the National Natural Science Foundation of China(32260780 and 31360297)the China Postdoctoral Science Foundation(2021M701513)+1 种基金the Jiangxi 2011 Collaborative Innovation Centre of Postharvest Key Technology and Quality Safety of Fruits and Vegetables,China(JXGS-05)the Gan Po 555 Engineering Excel ence Talents Project in Jiangxi Province,China。
文摘Rice is the world's largest food crop,but it often encounters flowering asynchronization problems during hybrid rice seed production.In addition,the slow closure of female florets leads to seed mildew and affects the quality.The hormone abscisic acid(ABA)plays a crucial role in plant responses to abiotic stresses.Previous studies showed that exogenous ABA promotes floret closure,although the molecular mechanisms and effects of endogenous ABA on floret closure remain unknown.In this study,the effect of endogenous ABA on floret closure and the molecular mechanism by which ABA promotes floret closure through sugar transporters were investigated by changing the expression levels of OsNCED3 and OsPYL1 in rice.The results showed that overexpression(OE)-OsNCED3increased the endogenous ABA level of florets.Florets closed 5.91 min earlier and OsNCED3 gene knockout line delayed the closure of florets by 5.08 min compared with the wild type.In addition,OsPYL1 regulated the endogenous ABA content and changed the sensitivity to ABA such that the floret closure times for OE and CRISPR-Cas9(CR)were 9.84 min earlier and 12.78 min later,respectively,resulting in an increase in the split husk rate to 15.4%.The gene expression levels of some sugar transporters(STs)changed.The OsPYL1 and OsSWEET4proteins could interact on the cell membrane.These results indicate that ABA promotes the closure of rice florets and the enhanced sensitivity to ABA promotes this effect even more.The molecular mechanism is mainly related to downstream sugar transporters that respond to the ABA signaling pathway,especially OsSWEET4.
基金Supported by Capital’s Funds for Health Improvement and Research(No.2024-2-4087)Central Guidance for Local Scientific and Technological Development Funding Projects(No.2022ZY0026).
文摘Dear Editor,X-linked retinoschisis(XLRS)is a rare X-linked recessive disorder predominantly afflicting young males.The schisis of the retinal layers is a result of deleterious mutations in the RS1 gene.Insufficient epidemiological data has caused significant variation in reported global prevalence,with estimates fluctuating between 1 in 5000 and 1 in 30000 individuals[1].A large follow-up multicenter study recently published has yielded noteworthy findings concerning the phenotypic spectrum,long-term natural history,and genotype of XLRS.The investigation revealed a significant variability in visual function and disease progression,with particular variants of the RS1 gene displaying diverse phenotypic expressions,suggesting the intricate genetic basis underlying this disorder[2].The range of visual impairments associated with XLRS is extensive,varying from minor to severe.This condition is also characterized by specific retinal abnormalities,including radial streaks emanating from a divided central fovea,schisis affecting the inner layers of the retina in peripheral areas,and a diminished amplitude ratio of b-to a-wave,or even an electronegative electroretinography(ERG)[3].At their initial consultation,the majority of individuals with XLRS exhibit visual acuity(VA)levels between 20/60 and 20/120.However,there is a significant diversity in the condition’s presentation and progression,even among relatives,with VA levels spanning from near-normal to complete loss of sight[4-5].While vision tends to be reasonably consistent over several years for those with XLRS,there is documentation of a more rapid decline in later adulthood,specifically during the fourth and fifth decades,due to central retinal degeneration[5-7].Moreover,those with XLRS face an elevated risk for serious visual issues,such as retinal detachment,vitreous hemorrhages,and neovascular glaucoma[4].Female carriers could be found with slightly abnormal retinal changes without clinical symptoms[5].Even within the same family,the manifestation and progression of the condition can vary greatly,with individuals experiencing anything from nearly normal vision to complete loss of sight[8-9].Earlier investigations have revealed that retinoschisisrelated cystoid degeneration can impact multiple layers of the retina,beginning at the retinal nerve fiber zone and continuing to the nuclear stratum,with considerable fluctuation in the severity of the schisis[10-13].
基金supported by the 2024 University Scientific Research Project of Guangzhou Education Bureau(Project No.24312286Certificate No.gd20249983112).
文摘Objective: To evaluate the efficacy of endovenous radiofrequency ablation (RFA) and laser ablation (EVLA) in the treatment of superficial varicose veins of the lower extremities. Methods: Seventy-eight patients with superficial varicose veins treated at a hospital between April 2022 and May 2023 were selected and divided into a radiofrequency ablation group (RFA group;39 cases) and a laser ablation group (EVLA group;39 cases) based on the treatment method. Operation time, postoperative recovery duration, venous clinical severity score (VCSS) changes, complication rates, closure rates, and recurrence rates were compared between the groups at 1 month, 3 months, and 12 months postoperatively. The postoperative therapeutic outcomes were comprehensively evaluated. Results: No significant differences in age, gender, disease grade, or disease course were observed between the groups (P > 0.05). The superficial varicose vein closure rate was 100% in both groups at 1 and 3 months postoperatively. At 12 months, the closure rate was 94.87% in the RFA group and 97.43% in the EVLA group, with no statistically significant difference (P > 0.05). No significant differences were observed in VCSS changes or complication incidence between the groups (P > 0.05). Conclusion: Radiofrequency ablation and laser ablation demonstrate comparable efficacy and safety in the treatment of superficial varicose veins of the lower extremities.
基金financial support from the Young Scientist Project of the National Key Research and Development Program of China(Grant No.2021YFC2900600)Beijing Nova Program(Grant No.20220484057)+1 种基金The authors acknowledge the financial support from the Natural Sciences and Engineering Research Council of Canada(Grant No.RGPIN-2018-06902)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique:https://irme.ca/en/).
文摘Underhand cut-and-fill mining has been widely used in underground mining operations,especially when the rock mass or orebody is of poor quality or prone to rockburst due to high stress.In such cases,mining workers should carry out all production activities under the cemented backfill roof or sill mat instead of a highly fractured and unstable rock roof or a strong rock roof with a high potential of rockburst.Therefore,the stability and required strength of the sill mat are critical issues for mining engineers.In 1991,Mitchell considered that sill mat could fail by caving,sliding,rotation,and flexure.Mitchell also proposed an analytical solution to determine the minimum required strength of the sill mat for each type of failure based on two stiff or immobile rock walls.However,recent publications using numerical modeling and field measurements indicate that the compressive stresses in the sill mat induced by rock wall closure due to a stope excavation beneath the sill mat can be significant.It is thus highly necessary to investigate the required strength of the sill mat by considering rock wall closure.In this study,the crushing failure of sill mat due to rock wall closure generated by underground excavation and a new failure mode called"crushing and caving”is revealed by numerical modeling.An analytical solution corresponding to each failure mode is then developed to estimate the minimum required cohesion(cmin)of the sill mat.A criterion is also proposed to determine if the sill mat fails by crushing or crushing-and-caving failure.The proposed analytical solution does not involve any correction coefficients.The validity of the proposed analytical solution is demonstrated by numerical modeling.The proposed analytical solution can thus be employed to predict the cmin of sill mat subjected to wall closure generated by underlying stope excavation.
基金supported by the National Natural Science Foundation of China(82271725).
文摘Congenital atrial septal defect(ASD)with severe scoliosis is a rare compound malformation inchildren.Severe sco liosis should be corrected as soon as possible.The growth rod is suitable for patients withearly scoliosis and obvious scoliosis under 10 years old.However,the fluoroscopic radiopaque of titaniumalloy plate will inevitably partly make the operative field of interventional occlusion blind.We presenta7-year-old Chinese girl with ASD and scoliosis who underwent spinal correction with a dual-growthrod.In this case,we performed transcatheter closure of ASD solely under the guidance of transthoracicechocardiography.Transthoracic echocardiography(TTE)has been reported as efficacious and safe forassessment and guidance of ASD occlusion.For patients with visual field occlusion under fluoroscopy,theapplication of TTE is efficacious and safe for assessmnent and guidance of ASD occlusion.
基金supported by the China Postdoctoral Science Foundation Funded Project(Grant No.2023M740385)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the support by the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(Contract No.VH-NG-1516).
文摘In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability of the fracture.To evaluate this relationship,we numerically generated self-affine fractures reproducing the scaling relationship of the power spectral density(PSD)of the measured fracture surfaces.The fractures were then subjected to a uniform and stepwise increase in normal stress.A fast Fourier transform(FFT)-based elastic contact model was used to simulate the fracture closure.The evolution of fracture contact area,fracture closure,and fracture normal stiffness were determined throughout the whole process.In addition,the fracture permeability at each step was calculated by the local cubic law(LCL).The influences of roughness exponent and correlation length on the fracture hydraulic and mechanical behaviors were investigated.Based on the power law of normal stiffness versus normal stress,the corrected cubic law and the linear relationship between fracture closure and mechanical aperture were obtained from numerical modeling of a set of fractures.Then,we derived a fracture normal stiffness-permeability equation which incorporates fracture geometric parameters such as the root-mean-square(RMS),roughness exponent,and correlation length,which can describe the fracture flow under an effective medium regime and a percolation regime.Finally,we interpreted the flow transition behavior from the effective medium regime to the percolation regime during fracture closure with the established stiffness-permeability function.
文摘BACKGROUND At present,prophylactic ileostomy is commonly used to protect distal intestinal anastomoses,particularly during the recovery period following colorectal surgery.However,after the ileum is returned to the abdominal cavity,abdominal closure using traditional vertical interrupted suturing is associated with a higher incidence of wound infections.For patients undergoing ileostomy closure,selecting an appropriate suturing method for the skin incision at the stoma site is crucial for improving patient prognosis.AIM To investigate the impact of three different skin suturing methods at the ileostomy closure site on patient prognosis.METHODS Thirty patients who underwent ileostomy closure at the Affiliated Hospital of Qinghai University between January 2024 and October 2024 were selected based on inclusion and exclusion criteria.The patients were divided into three groups:The purse-string suture group,the cross-suture group,and the vertical interrupted suture group,with 10 cases in each group.The purse-string suture group,cross-suture group,and vertical interrupted suture group used purse-string,cross,and vertical interrupted suturing methods,respectively,for the skin incision at the ileostomy closure site.RESULTS There were no statistically significant differences among the three groups in terms of operative time,intraoperative blood loss,time to resume liquid diet,time to first bowel movement,postoperative hospital stay,hospitalization costs,or levels of white blood cell count,hemoglobin,and albumin on the third postoperative day(P>0.05).Nevertheless,significant differences(P<0.05)were observed in incision suture removal time,wound healing time,C-reactive protein levels on the third postoperative day,visual analog scale pain scores during the first three postoperative days,and the incidence of surgical site infection.Overall,the therapeutic outcomes of the pursestring suture group and the cross-suture group were superior to the vertical interrupted suture group.CONCLUSION Using purse-string or cross-suturing methods for skin incision at the ileostomy closure site can shorten wound healing and suture removal times,reduce surgical site infection incidence and postoperative inflammatory response,alleviate incision pain,and promote rapid postoperative recovery.
基金supported by the National Key R&D Program of China(2022YFE0127900,2021YFD2200401)the National Natural Science Foundation of China(31901278).
文摘Ongoing climate change has a considerable influence on the seasonality,timing,and intensity of rainfall worldwide,and is also predicted to decrease snow cover in cold ecosystems.Larch is a widely distributed tree species in boreal Eurasia,calling for a comprehensive understanding of how larch adapts to changes in both rainfall and snowfall by adjusting carbon-water physiology.Here,we conducted a short-term rainfall(−60% ambient rainfall;three-year)and snowfall(−73% ambient snowfall;two-year)exclusions experiment in Larix gmelinii forest in northeastern China,and aimed to explore the responses of hydraulic(leaf pressure-volume traits,leaf and branch hydraulic conductivity and embolism resistance),stomatal(stomatal closure point and stomatal safety margin),and economic(photosynthetic rate,nutrient and non-structural carbohydrates contents)traits to rainfall and snowfall reductions.Despite the weak alternation of leaf and branch hydraulic traits,both rainfall and snowfall reductions significantly led to early stomatal closure and increased stomatal safety margins(the difference between stomatal closure point and xylem embolism threshold,describing drought resistance by merging both hydraulic and stomatal strategies).Reductions in rainfall and snowfall induced water or/and low-temperature stress,resulting in more conservative leaf economic traits,including a reduced photosynthetic rate,lower leaf nitrogen concentration,and higher leaf density.In addition,larch responded to reductions in rainfall and snowfall by up-regulating non-structural carbohydrates in the xylem,which helps repair embolism or lower the freezing point acting as osmolytes.Overall,our findings reveal that larch could adapt to the drought and snowpack reduction by strict stomatal regulation and investing non-structural carbohydrates in embolism repairing,at the cost of carbon assimilation.
基金financial support from the Young Scientist Project of the National Key Research and Development Program of China(Grant No.2021YFC2900600)the Beijing Nova Program(Grant No.20220484057)+1 种基金The authors acknowledge the financial support from the Natural Sciences and Engineering Research Council of Canada(Grant No.RGPIN-2018-06902)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique:https://irme.ca/en/).
文摘In the underhand cut-and-fill mining method,a sill mat(i.e.an artificial horizontal pillar)constructed by cemented backfill is essential to prevent mine workers from being directly exposed under problematic rock roofs.A critical issue is to determine the minimum required strength of the sill mat to ensure a safe and cost-effective design.Until now,Mitchell’s analytical solution is the only available option,considering two stiff and immobile rock walls.Unavoidable rock wall closure associated with stope excavation below the sill mat was neglected.This,along with other undefined parameters,explains why Mitchell’s solution is rarely used in sill mat design.A new analytical solution for determining the minimum required strength of the sill mat accounting for wall closure is necessary.In this study,a closed-form analytical solution for estimating rock wall closure generated by stope excavation below a sill mat is developed by using Salamon’s and Flamant’s models.The proposed analytical solution does not contain any coefficients of correction or calibration.Despite several assumptions(or somewhat of oversimplifications)necessary to render a simple analytical solution possible,good agreements are obtained between the rock wall closures predicted by applying the proposed analytical solution and those obtained numerically with FLAC3D for many cases with arbitrarily chosen geometrical and material parameters.The proposed analytical solution is therefore validated and can be used to evaluate the rock wall closure generated by stope excavation below a sill mat.
文摘BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli including stroke,and decompression sickness.We aimed to study the trends in utilization and reimbursements of transcatheter ASD/PFO closure devices.AIM To analyze trends in utilization and Medicare reimbursements for transcatheter ASD/PFO closure procedures from 2013 to 2022.METHODS A query of administrative data on United States Medicare beneficiaries undergoing transcatheter ASD/PFO was conducted from 2013 to 2022 using the Centers for Medicare and Medicaid Services Part B National Summary Data File.Inflation adjustments were made using the 2023 Consumer Price Index.Trend analysis was quantified using growth rate and simple linear regression calculations.All analyses were performed using Microsoft Excel 16.77.1(2023).RESULTS The annual number of transcatheter ASD/PFO closure procedures increased by 81%since 2013,with an average yearly growth rate of 44%cases per year(P<0.001).Annual Medicare reimbursements for transcatheter ASD/PFO therapies mirrored the annual procedure trends.The per-case reimbursements decreased by 18%,i.e.,$1128.80 in 2013 and$770.21 in 2022(P<0.001).There was a significant drop in the number of procedures in the year 2020,which correlates to the onset of the coronavirus disease 2019 pandemic,followed by a sharp uptick in the number of cases in 2021 and 2022.CONCLUSION Medicare utilization of transcatheter ASD/PFO closure therapies has grown significantly in procedural volume from 2013 to 2022.However,this has been accompanied by a decrease in per-case reimbursements.
文摘On 30 September 2024,the UK shuttered its last remaining coal-fired power plant[1].The closure marks a historic milestone,the end of 142 years of coal fueled prosperity.The country opened the world’s first plant to supply electric streetlamps in 1882,spark-ing a global energy revolution that has led to today’s nearly univer-sally electrified world.
文摘This paper comprehensively explores the technical principles and application practice of Sainaoning absorbable dural sealant medical adhesive in dural closure.It elaborates on the research and development background of Sainaoning,analyzes its composition,action mechanism,and product characteristics in detail,and presents the results of pre-clinical and clinical studies.The application of Sainaoning in different craniotomy surgeries is discussed,and its effectiveness and safety are evaluated.The paper also analyzes the challenges in its application and proposes corresponding countermeasures,aiming to provide a comprehensive understanding and reference for the clinical use and further development of Sainaoning.
文摘BACKGROUND Gastric ulcer perforation is a critical condition that can lead to significant morbidity and mortality if not promptly addressed.It is often the result of chronic peptic ulcer disease,which is characterized by a breach in the gastric wall due to ulceration.Surgical intervention is essential for managing this life-threatening complication.However,the optimal surgical technique remains debatable among clinicians.Various methods have been employed,including simple closure,omental patch repair,and partial gastrectomy,each with distinct advantages and disadvantages.Understanding the comparative efficacy and postoperative outcomes of these techniques is crucial for improving patient care and surgical decision-making.This study addresses the need for a comprehensive analysis in this area.AIM To compare the efficacy and postoperative complications of different surgical methods for the treatment of gastric ulcer perforation.METHODS A retrospective analysis was conducted on 120 patients who underwent surgery for gastric ulcer perforation between September 2020 and June 2023.The patients were divided into three groups based on the surgical method:Simple closure,omental patch repair,and partial gastrectomy.The primary outcomes were the operative success rate and incidence of postoperative complications.Secondary outcomes included the length of hospital stay,recovery time,and long-term quality of life.RESULTS The operative success rates for simple closure,omental patch repair,and partial gastrectomy were 92.5%,95%,and 97.5%,respectively.Postoperative complications occurred in 20%,15%,and 17.5%of patients in each group,respectively.The partial gastrectomy group showed a significantly longer operative time(P<0.001)but the lowest rate of ulcer recurrence(2.5%,P<0.05).The omental patch repair group demonstrated the shortest hospital stay(mean 7.2 days,P<0.05)and fastest recovery time.CONCLUSION While all three surgical methods showed high success rates,omental patch repair demonstrated the best overall outcomes,with a balance of high efficacy,low complication rates,and shorter recovery time.However,the choice of the surgical method should be tailored to individual patient factors and the surgeon’s expertise.
基金Supported by the Shenyang Science and Technology,No.22-321-32-15Department of Science and Technology of Liaoning Province,No.2023JH2/101600015.
文摘BACKGROUND Gastric subepithelial lesions(SELs)are elevated lesions originating from the muscularis mucosa,submucosa,or muscularis propria,and may also include extraluminal lesions.For small SELs(less than 5 cm),complete endoscopic excision is the preferred treatment.Endoscopic full-thickness resection(EFTR)has proven to be an effective approach.AIM To evaluate the efficacy of the interrupted closure technique compared to the traditional closure technique in EFTR for gastric SELs.METHODS This single-center,prospective,randomized controlled trial was conducted at a tertiary hospital from September 2023 to September 2024.A total of 90 patients who underwent EFTR for gastric SELs were randomly allocated to either the interrupted closure group(n=44)or the traditional closure group(n=46).RESULTS All patients had complete resection and wound closure without any severe postoperative complications.The incidence of intraoperative gas-related complications was significantly lower in the interrupted closure group than in the traditional closure group(2.27%vs 26.09%,P=0.001),demonstrating interrupted closure technique can reduce the incidence of gas-related issues.Statistical analysis revealed that the incidence of postoperative infection was significantly lower in the experimental group than in the control group(15.91%vs 41.30%,P=0.008).Additionally,the median duration of antibiotic use was lower in the experimental group(3.5 days vs 5 days,P=0.013).Abdominal pain levels on postoperative days 1 and 4 were also lower in the experimental group compared to the control group(P<0.001).CONCLUSION The interrupted closure technique in EFTR for treating gastric SELs is safe and effective,reducing the incidence of intraoperative gas complications and postoperative infections.
