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
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
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
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
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
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
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
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 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
MANTA vascular closure device is an alternative vascular access closure device that is predominantly designed for large bore arteriotomy procedures.Its implementation to reduce morbidity and mortality following percut...MANTA vascular closure device is an alternative vascular access closure device that is predominantly designed for large bore arteriotomy procedures.Its implementation to reduce morbidity and mortality following percutaneous procedures including peripheral veno-arterial(VA)-extracorporeal membrane oxygenation(ECMO)in critically ill patients with various severe clinical conditions such as refractory cardiogenic shock remains to be under scientific discussion.The use of the MANTA vascular closure device leads to a sufficient reduction in a number of post-decannulation complications such as bleeding,vascular complications,inflammatory reactions and major amputation.Furthermore,the technical success of percutaneous decannulation of VA-ECMO with the MANTA vascular closure device appears to be safe and effective.It has been reported that MANTA vascular closure device exerted a strict similarity with other vascular surgical systems in safe profile regardless of the indication for its utilization.Overall,the immobilized patients achieved a favorable recovery outcome with MANTA including safe decannulation and low risk of vascular complications.The authors suggest the use of pulse wave distal Doppler technology for early detection of these clinically relevant complications.In conclusion,MANTA vascular closure device seems to be safe and effective technical approach to provide low-risk vascular assess for a long time for severe sick individuals.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
This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwent...This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.展开更多
The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T ...The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T axle steel specimens.The variation of the plastic-induced crack closure(PICC)effect and the roughness-induced crack closure(RICC)effect during crack deflection in the mixed-mode is examined in this study.The results show that the load perpendicular to the crack propagation direction hinders the slip effect caused by the load parallel to the crack propagation direction under mixed-mode loading,and the crack deflection is an intuitive manifestation of the interaction between the PICC and RICC.The proportion of the RA value change on the crack side caused by contact friction was reduced by the interaction between PICC and RICC.The roughness of the crack surface before and after the crack deflection is different,and the spatial torsion crack surface is formed during the crack propagation process.With the increase of the crack length,the roughness of the fracture surface increases.During the crack deflection process,the PICC value fluctuates around 0.2,and the RICC value is increased to 0.15.展开更多
Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting th...Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting the deep shale gas reservoir.However,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas production.In this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas production.Then we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale matrix.When the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture method.Compared with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the fracture.Numerical simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary fractures.Shale creep and proppant embedment both increase the degree of fracture closure.The reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the past.However,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield reduction.This study is helpful to understand the mechanism of hydraulic fracture closure.Therefore,it provides the theoretical guidance for maintaining the long-term effectiveness of hydraulic fractures.展开更多
Hot isostatic pressing(HIP)is usually applied to reduce the defects including cracks and pores in the materials prepared by laser powder bed fusion(LPBF).In the present research,in order to improve the relative densit...Hot isostatic pressing(HIP)is usually applied to reduce the defects including cracks and pores in the materials prepared by laser powder bed fusion(LPBF).In the present research,in order to improve the relative density and mechanical property,HIP was employed on the LPBF-processed Al-Cr-Fe-Ni-V high-entropy alloy(HEA)with microcracks and pores.The microstructure evolution and property improvement induced by HIP were investigated.In the LPBF-processed HEA,the microcracks were caused by residual stress and element segregation,and these microcracks as well as the pores reduced significantly after HIP treatments.Remarkably,HIP temperature has a more critical effect on the microcrack closure than the holding time,thus,microcracks and pores still existed after HIP-1 treatment(1273 K,8 h),while HIP-2 treatment(1473 K,4 h)could close the microcracks significantly.The crack closure was attributed to the interfacial diffusion of the alloying element under high temperature accompanied by high pressure,and the degree of element diffusion at both interfaces of the cracks determined the bonding strength after crack closure.Higher temperatures at high pressure induced more adequate element diffusion and higher bonding strength.The above high temperature and high pressure also induced the growth of the L1_(2) phase and the precipitation of the B2 phase in HEA.Consequently,the tensile strength and elonga-tion of the LPBF-processed HEA after HIP-2 treatment were simultaneously enhanced(80.7%and 222.5%higher than that of LPBF-processed HEA,respectively).This could be attributed to the combined effect of microcrack/pore closure and precipitation strengthening.The strengthening effect of the B2 phase and L1_(2) phase accounted for 53%(dislocation by-pass mechanism)and 47%(dislocation shearing mechanism)of the total precipitation strengthening,respectively.展开更多
BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complic...BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.展开更多
Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filt...Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filtration surgery or other intraocular procedures are more susceptible to severe complications,including choroidal effusion,malignant glaucoma,and explosive choroidal hemorrhage,all of which can lead to vision loss[1].This dilemma is particularly pronounced in patients with shorter axial lengths.Micropulse transscleral laser therapy(M-TLT),also known as micropulse transscleral cyclophotocoagulation(MP-TSCPC),is a nonincisional laser therapy surgery for glaucoma[2].In 2015,Golan and Kurtz[3]were the first to report four patients with secondary angle-closure glaucoma in nanophthalmos with axial lengths ranging between 17 and 19 mm(mean 18 mm)who were successfully treated with M-TLT,and choroidal detachment was observed in all patients(recovery spontaneously in two patients and recovery after systemic steroid treatment in the other two),of which two had a slight decrease in visual acuity.展开更多
BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And mo...BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective treatment for diabetic foot that can significantly improve limb salvage rates.The use of VAC after ER simplifies and facilitates wound repair.展开更多
BACKGROUND Colorectal foreign bodies are commonly encountered during surgery.They are frequently observed in men 20 to 90 years of age and have bimodal age distribution.Surgical management is necessary for cases of re...BACKGROUND Colorectal foreign bodies are commonly encountered during surgery.They are frequently observed in men 20 to 90 years of age and have bimodal age distribution.Surgical management is necessary for cases of rectal perforation.However,surgical site infections are the most common complications after colorectal surgery.CASE SUMMARY We discuss a case of rectal perforation in a patient who presented to our hospital 2 d after its occurrence.The perforation occurred as a result of the patient inserting a sex toy in his rectum.Severe peritonitis was attributable to delayed presentation.CONCLUSION Vacuum-assisted closure was performed to treat the wound,which healed well after therapy.No complications were noted.展开更多
BACKGROUND Ostomy is a common surgery usually performed to protect patients from clinical symptoms caused by distal anastomotic leakage after colorectal cancer(CRC)surgery and perforation or to relieve intestinal obst...BACKGROUND Ostomy is a common surgery usually performed to protect patients from clinical symptoms caused by distal anastomotic leakage after colorectal cancer(CRC)surgery and perforation or to relieve intestinal obstruction.AIM To analyze the complications after transverse colostomy closure.METHODS Patients who underwent transverse colostomy closure from Jan 2015 to Jan 2022 were retrospectively enrolled in a single clinical center.The differences between the complication group and the no complication group were compared.Logistic regression analyses were conducted to find independent factors for overall complications or incision infection.RESULTS A total of 102 patients who underwent transverse colostomy closure were enrolled in the current study.Seventy(68.6%)patients underwent transverse colostomy because of CRC related causes.Postoperative complications occurred in 30(29.4%)patients and the most frequent complication occurring after transverse colostomy closure was incision infection(46.7%).The complication group had longer hospital stays(P<0.01).However,no potential risk factors were identified for overall complications and incision infection.CONCLUSION The most frequent complication occurring after transverse colostomy closure surgery in our center was incision infection.The operation time,interval from transverse colostomy to reversal,and method of anastomosis might have no impact on the postoperative complications.Surgeons should pay more attention to aseptic techniques.展开更多
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.
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 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.
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.
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.
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.
文摘MANTA vascular closure device is an alternative vascular access closure device that is predominantly designed for large bore arteriotomy procedures.Its implementation to reduce morbidity and mortality following percutaneous procedures including peripheral veno-arterial(VA)-extracorporeal membrane oxygenation(ECMO)in critically ill patients with various severe clinical conditions such as refractory cardiogenic shock remains to be under scientific discussion.The use of the MANTA vascular closure device leads to a sufficient reduction in a number of post-decannulation complications such as bleeding,vascular complications,inflammatory reactions and major amputation.Furthermore,the technical success of percutaneous decannulation of VA-ECMO with the MANTA vascular closure device appears to be safe and effective.It has been reported that MANTA vascular closure device exerted a strict similarity with other vascular surgical systems in safe profile regardless of the indication for its utilization.Overall,the immobilized patients achieved a favorable recovery outcome with MANTA including safe decannulation and low risk of vascular complications.The authors suggest the use of pulse wave distal Doppler technology for early detection of these clinically relevant complications.In conclusion,MANTA vascular closure device seems to be safe and effective technical approach to provide low-risk vascular assess for a long time for severe sick individuals.
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 grants from National High-Level Hospital Clinical Research Funding(2023-GSP-RC-04).
文摘This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.
基金Supported by National Natural Science Foundation of China (Grant No.52375159)National Railway Administration of China (Grant No.KF2023-025)the Independent Research Project of the State Key Laboratory of Traction Power (Grant No.2022TPL_T03)。
文摘The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T axle steel specimens.The variation of the plastic-induced crack closure(PICC)effect and the roughness-induced crack closure(RICC)effect during crack deflection in the mixed-mode is examined in this study.The results show that the load perpendicular to the crack propagation direction hinders the slip effect caused by the load parallel to the crack propagation direction under mixed-mode loading,and the crack deflection is an intuitive manifestation of the interaction between the PICC and RICC.The proportion of the RA value change on the crack side caused by contact friction was reduced by the interaction between PICC and RICC.The roughness of the crack surface before and after the crack deflection is different,and the spatial torsion crack surface is formed during the crack propagation process.With the increase of the crack length,the roughness of the fracture surface increases.During the crack deflection process,the PICC value fluctuates around 0.2,and the RICC value is increased to 0.15.
基金the supports provided by China University of Petroleum,Beijing(Grand No.ZX20230042)the National Natural Science Foundation of China(Grand No.52334001and Grand No.51904314)。
文摘Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting the deep shale gas reservoir.However,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas production.In this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas production.Then we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale matrix.When the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture method.Compared with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the fracture.Numerical simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary fractures.Shale creep and proppant embedment both increase the degree of fracture closure.The reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the past.However,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield reduction.This study is helpful to understand the mechanism of hydraulic fracture closure.Therefore,it provides the theoretical guidance for maintaining the long-term effectiveness of hydraulic fractures.
基金National Natural Science Foundation of China(Grant Nos.51901004,52001025,and 52171060)State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China.
文摘Hot isostatic pressing(HIP)is usually applied to reduce the defects including cracks and pores in the materials prepared by laser powder bed fusion(LPBF).In the present research,in order to improve the relative density and mechanical property,HIP was employed on the LPBF-processed Al-Cr-Fe-Ni-V high-entropy alloy(HEA)with microcracks and pores.The microstructure evolution and property improvement induced by HIP were investigated.In the LPBF-processed HEA,the microcracks were caused by residual stress and element segregation,and these microcracks as well as the pores reduced significantly after HIP treatments.Remarkably,HIP temperature has a more critical effect on the microcrack closure than the holding time,thus,microcracks and pores still existed after HIP-1 treatment(1273 K,8 h),while HIP-2 treatment(1473 K,4 h)could close the microcracks significantly.The crack closure was attributed to the interfacial diffusion of the alloying element under high temperature accompanied by high pressure,and the degree of element diffusion at both interfaces of the cracks determined the bonding strength after crack closure.Higher temperatures at high pressure induced more adequate element diffusion and higher bonding strength.The above high temperature and high pressure also induced the growth of the L1_(2) phase and the precipitation of the B2 phase in HEA.Consequently,the tensile strength and elonga-tion of the LPBF-processed HEA after HIP-2 treatment were simultaneously enhanced(80.7%and 222.5%higher than that of LPBF-processed HEA,respectively).This could be attributed to the combined effect of microcrack/pore closure and precipitation strengthening.The strengthening effect of the B2 phase and L1_(2) phase accounted for 53%(dislocation by-pass mechanism)and 47%(dislocation shearing mechanism)of the total precipitation strengthening,respectively.
基金Supported by the Zhejiang Provincial Natural Science Foundation of China,No.LQ20H260002.
文摘BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.
文摘Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filtration surgery or other intraocular procedures are more susceptible to severe complications,including choroidal effusion,malignant glaucoma,and explosive choroidal hemorrhage,all of which can lead to vision loss[1].This dilemma is particularly pronounced in patients with shorter axial lengths.Micropulse transscleral laser therapy(M-TLT),also known as micropulse transscleral cyclophotocoagulation(MP-TSCPC),is a nonincisional laser therapy surgery for glaucoma[2].In 2015,Golan and Kurtz[3]were the first to report four patients with secondary angle-closure glaucoma in nanophthalmos with axial lengths ranging between 17 and 19 mm(mean 18 mm)who were successfully treated with M-TLT,and choroidal detachment was observed in all patients(recovery spontaneously in two patients and recovery after systemic steroid treatment in the other two),of which two had a slight decrease in visual acuity.
文摘BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective treatment for diabetic foot that can significantly improve limb salvage rates.The use of VAC after ER simplifies and facilitates wound repair.
文摘BACKGROUND Colorectal foreign bodies are commonly encountered during surgery.They are frequently observed in men 20 to 90 years of age and have bimodal age distribution.Surgical management is necessary for cases of rectal perforation.However,surgical site infections are the most common complications after colorectal surgery.CASE SUMMARY We discuss a case of rectal perforation in a patient who presented to our hospital 2 d after its occurrence.The perforation occurred as a result of the patient inserting a sex toy in his rectum.Severe peritonitis was attributable to delayed presentation.CONCLUSION Vacuum-assisted closure was performed to treat the wound,which healed well after therapy.No complications were noted.
基金The ethics committee of the First Affiliated Hospital of Chongqing Medical University approved this study,No.K2024-008-01.
文摘BACKGROUND Ostomy is a common surgery usually performed to protect patients from clinical symptoms caused by distal anastomotic leakage after colorectal cancer(CRC)surgery and perforation or to relieve intestinal obstruction.AIM To analyze the complications after transverse colostomy closure.METHODS Patients who underwent transverse colostomy closure from Jan 2015 to Jan 2022 were retrospectively enrolled in a single clinical center.The differences between the complication group and the no complication group were compared.Logistic regression analyses were conducted to find independent factors for overall complications or incision infection.RESULTS A total of 102 patients who underwent transverse colostomy closure were enrolled in the current study.Seventy(68.6%)patients underwent transverse colostomy because of CRC related causes.Postoperative complications occurred in 30(29.4%)patients and the most frequent complication occurring after transverse colostomy closure was incision infection(46.7%).The complication group had longer hospital stays(P<0.01).However,no potential risk factors were identified for overall complications and incision infection.CONCLUSION The most frequent complication occurring after transverse colostomy closure surgery in our center was incision infection.The operation time,interval from transverse colostomy to reversal,and method of anastomosis might have no impact on the postoperative complications.Surgeons should pay more attention to aseptic techniques.
