The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short （le...The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short （less than some critical value） do not result in system failure, and such a repair interval is omitted from the downtime record. Usually, the underlying process is Markov process if the durations of working and repair time have the negative-exponential distributions, but the new system has not the Markov properties, which is worth to study. The reliability indexes such as instantaneous availability and steady-state availabilities for the new system are given through probability analysis. A numerical example is given to illustrate the results.展开更多
BACKGROUND:MAVERIC(Mitral Valve Repair Clinical Trial)validates the safety and effi cacy of the ARTO system.We here report the fi rst two successful cases of utilizing the ARTO system in patients with symptomatic hear...BACKGROUND:MAVERIC(Mitral Valve Repair Clinical Trial)validates the safety and effi cacy of the ARTO system.We here report the fi rst two successful cases of utilizing the ARTO system in patients with symptomatic heart failure(HF)with functional mitral regurgitation(FMR)in Asia.METHODS:Two patients,aged 70 and 63,had severe HF with FMR.Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50%with severe mitral regurgitation(MR)in both patients.Optimizing drug treatment could not mitigate their symptoms.Therefore,we used the ARTO system to repair the mitral valve for these patients on March 5 and 6,2019,respectively.RESULTS:Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients.MR was decreased immediately after the procedures in both patients.The 30-day and 3-month transthoracic echocardiography(TTE)revealed a moderate to severe MR in both patients,and the New York Heart Association(NYHA)scales were also partially improved.CONCLUSION:The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR,and the patient selection appears to be crucial.展开更多
In this paper,the solution of a parallel redundant repairable system is investigated.by using the method of functional analysis.Especially,the linear semigroups of operator theory on Banach space,we prove the existenc...In this paper,the solution of a parallel redundant repairable system is investigated.by using the method of functional analysis.Especially,the linear semigroups of operator theory on Banach space,we prove the existence of the strictly dominant eigenvalue,and show the linear stability of solution.展开更多
This paper considers a two–unit same cold standby repairable system with a replaceable repair facility and delay repair .The failure time of unit is assumed to follow exponential distribution , and the repair time an...This paper considers a two–unit same cold standby repairable system with a replaceable repair facility and delay repair .The failure time of unit is assumed to follow exponential distribution , and the repair time and delay time of failed unit are assumed to follow arbitrary distributions , whereas the failure and replacement time distributions of the repair facility are exponential and arbitrary . By using the Markov renewal process theory, some primary reliability quantities of the system are obtained.展开更多
Probiotics participate in various physiological activities and contribute to body health.However,their viability and bioefficacy are adversely affected by gastrointestinal harsh conditions,such as gastric acid,bile sa...Probiotics participate in various physiological activities and contribute to body health.However,their viability and bioefficacy are adversely affected by gastrointestinal harsh conditions,such as gastric acid,bile salts and various enzymes.Fortunately,encapsulation based on various nanomaterials shows tremendous potential to protect probiotics.In this review,we introduced some novel encapsulation technologies involving nanomaterials in view of predesigned stability and viability,selective adhesion,smart release and colonization,and efficacy exertion of encapsulated probiotics.Furthermore,the interactions between encapsulated probiotics and the gastrointestinal tract were summarized and analyzed,with highlighting the regulatory mechanisms of encapsulated probiotics on intestinal mechanical barrier,chemical barrier,biological barrier and immune barrier.This review would benefit the food and pharmaceutical industries in preparation and utilization of multifunctional encapsulated probiotics.展开更多
Spent battery recycling has received considerable attention because of its economic and environmental potential.A large amount of retired graphite has been produced as the main electrode material,accompanied by a deta...Spent battery recycling has received considerable attention because of its economic and environmental potential.A large amount of retired graphite has been produced as the main electrode material,accompanied by a detailed exploration of the repair mechanism.However,they still suffer from unclear repair mechanisms and physicochemical evolution.In this study,spent graphite was repaired employing three methodologies:pickling-sintering,pyrogenic-recovery,and high-temperature sintering.Owing to the catalytic effect of the metal-based impurities and temperature control,the as-obtained samples displayed an ordered transformation,including the interlayer distance,crystalline degree,and grain size.As anodes of lithium ions batteries,the capacity of repaired samples reached up to 310 mA h g^(-1)above after 300loops at 1.0 C,similar to that of commercial graphite.Meanwhile,benefitting from the effective assembly of carbon atoms in internal structure of graphite at>1400℃,their initial coulombic efficiency were>87%.Even at 2.0 C,the capacity of samples remained approximately 244 mA h g^(-1)after 500 cycles.Detailed electrochemical and kinetic analyses revealed that a low temperature enhanced the isotropy,thereby enhancing the rate properties.Further,economic and environmental analyses revealed that the revenue obtained through suitable pyrogenic-recovering manners was approximately the largest value(5500$t^(-1)).Thus,this study is expected to clarify the in-depth effect of different repair methods on the traits of graphite,while offering all-round evaluations of repaired graphite.展开更多
Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the ...Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the effects of different patch and parent laminate stacking sequences on the enhancement of impact strength of Carbon Fiber Reinforced Polymers(CFRP)composites by utilising the adhesively bonded external patch repair technique.Damage evolution study is also performed with the aid of Acoustic Emission(AE).Two different quasi-isotropic configurations were selected for the parent laminate,viz.,[45°/45°/0°/0°]s and[45°/0°/45°/0°]s.Quasi Static Indentation(QSI)test was performed on both the pristine laminates,and damage areas were detected by using the C-scan inspection technique.Damaged laminates were repaired by using a single-sided patch of two different configurations,viz.,[45°/45°/45°/45°]and[45°/0°/0°/45°],and employing a circular plug to fill the damaged hole.Four different combinations of repaired laminates with two configurations of each parent and patch laminate were produced,which were further subjected to the QSI test.The results reveal the effectiveness of the repair method,as all the repaired laminates show higher impact resistance compared to the respective pristine laminates.Patches of[45°/0°/0°/45°]configuration when repaired by taking[45°/45°/0°/0°]s and[45°/0°/45°/0°]s as parents exhibited 68%and 73%higher peak loads,respectively,than the respective pristine laminates.Furthermore,parent and patch of configuration[45°/0°/45°/0°]s and[45°/0°/0°/45°],respectively,attain the highest peak load,whereas[45°/45°/0°/0°]s and[45°/45°/45°/45°]combinations possess the most gradual decrease in the load.展开更多
This paper deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantiti...This paper deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantities of this system in equilibrium are obtained.展开更多
The roadway support in many places of Jiulongkou Colliery, Fengfeng Mining Bureau, such as in the Permanent transportation roadway, was failed or locally caved, which seriously affected the colliery’s coal production...The roadway support in many places of Jiulongkou Colliery, Fengfeng Mining Bureau, such as in the Permanent transportation roadway, was failed or locally caved, which seriously affected the colliery’s coal production performance and safety. Based on analysis of supporting objects for roadway repairing, this paper proposes the supporting parameters and condruction technics. The industrial ted of 70m long roadway repairing shows that the proposed parameters and technics of bolt shotcrete and mesh support for roadway repairing are reasouable, bring good technical and economic results for the colliery, and the repairing is successful.展开更多
BACKGROUND:Fatal aortic rupture caused by esophageal foreign body(EFB),is associated with a high mortality,but can be prevented by thoracic endovascular aorta repair(TEVAR)that performed increasingly as technology imp...BACKGROUND:Fatal aortic rupture caused by esophageal foreign body(EFB),is associated with a high mortality,but can be prevented by thoracic endovascular aorta repair(TEVAR)that performed increasingly as technology improves.This study aims to investigate the cause,management and prognosis of suspected penetrating aortoesophageal foreign body injury.METHODS:Twelve cases who met the criteria were enrolled in this study.The demographic and clinical data were reviewed for evaluating the characteristics of EFB.RESULTS:Among 12 cases enrolled,7 were males and 5 were females,with an age 27–86 years.The distance of EFB from aorta(DFA)of 7 cases were less than or equal to 0 mm,5 cases were 0–2 mm.Eleven cases were managed with TEVAR,only one case was with open surgery standby but finally treated by flexible endoscopy(FE)successfully,without TEVAR.In group with TEVAR,EFB of 7 cases were successfully removed by rigid endoscopy(RE),and one of them was failed at the first RE treatment.EFB of 2 cases were successfully removed by open surgery with TEVAR,and other 9 cases were managed by endoscopies with TEVAR.The mean length of stay of hospitalization(LOS)and length of ICU stay of patients treated by open surgery with TEVAR(18.50±2.12 days and 5.50±0.71 days)was significantly longer than those of patients treated by endoscopy with TEVAR(7.00±2.74 days and 1.33±1.12 days,P<0.001 and P=0.001,respectively).Five cases had severe complications.CONCLUSION:Rational application of TEVAR can be a life-saving management for aortoesophageal foreign body injury,and jointed with endoscopy is safe and effective with a shorter length of ICU or total hospital stay.展开更多
Bone defects caused by trauma,tumor,or osteoarthritis remain challenging due to the lack of effective treatments in clinic.Stem cell transplantation has emerged as an alternative approach for bone repair and attracted...Bone defects caused by trauma,tumor,or osteoarthritis remain challenging due to the lack of effective treatments in clinic.Stem cell transplantation has emerged as an alternative approach for bone repair and attracted widespread attention owing to its excellent biological activities and therapy effect.The attempts to develop this therapeutic approach focus on the generation of effective cell delivery vehicles,since the shortcomings of direct injection of stem cells into target tissues.Here,we developed a novel core-shell microcapsule with a stem cell-laden core and a biomass shell by using all-aqueous phase microfluidic electrospray technology.The designed core-shell microcapsules showed a high cell viability during the culture procedure.In addition,the animal experiments exhibited that stem cell-laden core-shell microcapsules have good biocompatibility and therapeutic effect for bone defects.This study indicated that the core-shell biomass microcapsules generated by microfluidic electrospray have promising potential in tissue engineering and regenerative medicine.展开更多
Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework...Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework.Herein,post-synthetic and in-situ vacancy repairing strategies are proposed for the synthesis of highquality FeHCF in a highly concentrated Na_(4)Fe(CN)_(6) solution.Both the post-synthetic and in-situ vacancy repaired FeHCF products(FeHCF-P and FeHCF-I)show the significant decrease in the number of vacancy defects and the reinforced structure,which can suppress the side reactions and activate the capacity from low-spin Fe in FeHCF.In particular,FeHCF-P delivers a reversible discharge capacity of 131 mAh g^(−1) at 1 C and remains 109 mAh g^(−1) after 500 cycles,with a capacity retention of 83%.FeHCF-I can deliver a high discharge capacity of 158.5 mAh g^(−1) at 1 C.Even at 10 C,the FeHCF-I electrode still maintains a discharge specific capacity of 103 mAh g^(−1) and retains 75% after 800 cycles.This work provides a new vacancy repairing strategy for the solution synthesis of high-quality FeHCF.展开更多
Objective Acute kidney injury （AKI） frequently occurs after catheter-based interventional procedures and increases mortality. However, the implications of AKI before thoracic endovascular aneurysm repair （TEVAR） o...Objective Acute kidney injury （AKI） frequently occurs after catheter-based interventional procedures and increases mortality. However, the implications of AKI before thoracic endovascular aneurysm repair （TEVAR） of type B acute aortic dissection （AAD） remain unclear. This study evaluated the incidence, predictors, and in-hospital outcomes of AKI before TEVAR in patients with type B AAD. Methods Between 2009 and 2013, 76 patients were retrospectively evaluated who received TEVAR for type B AAD within 36 h from symptom onset. The patients were classified into no-AKI vs. AKI groups, and the severity of AKI was further staged according to kidney disease： im- proving global outcomes criteria before TEVAR. Results The incidence of preoperative AKI was 36.8%. In-hospital complications was significantly higher in patients with preoperative AKI compared with no-AKI （50.0% vs. 4.2%, respectively; P 〈 0.001）, including acute renal failure （21.4% vs. O, respectively; P 〈 0.001）, and they increased with severity of AKI （P 〈 0.001）. The maximum levels of body tem- perature and white blood cell count were significantly related to maximum serum creatinine level before TEVAR. Multivariate analysis showed that systolic blood pressure on admission （OR： 1.023; 95% CI： 1.003-1.044; P ： 0.0238） and bilateral renal artery involvement （OR： 19.076; 95% CI： 1.914 190.164; P = 0.0120） were strong predictors of preoperative AKI. Conclusions Preoperative AKI frequently occurred in patients with type B AAD, and correlated with higher in-hospital complications and enhanced inflammatory reaction. Systolic blood pressure on admission and bilateral renal artery involvement were major risk factors for AKI before TEVAR.展开更多
Wound healing,tissue repair and regenerative medicine are in great demand,and great achievements in these fields have been made.The traditional strategy of tissue repair and regeneration has focused on the level of ti...Wound healing,tissue repair and regenerative medicine are in great demand,and great achievements in these fields have been made.The traditional strategy of tissue repair and regeneration has focused on the level of tissues and organs directly;however,the basic process of repair at the cell level is often neglected.Because the cell is the basic unit of organism structure and function;cell damage is caused first by ischemia or ischemia-reperfusion after severe trauma and injury.Then,damage to tissues and organs occurs with massive cell damage,apoptosis and even cell death.Thus,how to achieve the aim of perfect repair and regeneration?The basic process of tissue or organ repair and regeneration should involve repair of cells first,then tissues and organs.In this manuscript,it is my consideration about how to repair the cell first,then regenerate the tissues and organs.展开更多
A new reliability allocation model has been built for engine system, which is a repairable system, and consists of a large number of mechanical components. The cost and reliability are taken as objective function and ...A new reliability allocation model has been built for engine system, which is a repairable system, and consists of a large number of mechanical components. The cost and reliability are taken as objective function and constraint condition respectively. The parameters of components lifetime distribution are given as decision variables, and the component lifetimes are assumed to follow that Weibull distribution. The allocation is separated into two steps to reduce calculated amount of one allocation. Genetic algorithm and Monte Carlo method are applied to solve distribution parameters and system cost separately.展开更多
Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormali...Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.展开更多
Objective Type II endoleak is the most common subtype of endoleak as a complication after endovascular aneurysm repair(EVAR).The efficacy of transarterial(TA)embolization and translumber(TL)embolization in the managem...Objective Type II endoleak is the most common subtype of endoleak as a complication after endovascular aneurysm repair(EVAR).The efficacy of transarterial(TA)embolization and translumber(TL)embolization in the management of type II endoleak remains equipoise.The aim of this study is to compare the technical and clinical success between TA embolization andTL embolization for type II endoleak after EVAR.Methods The protocol was registered(CRD 42018114453)and the electronic databases(Pubmed,Embase,Web of Science,and Cochrane)were systematically searched till March 2019.The search terms included EVAR,type II endoleak,and embolization.The articles were read and extracted by two authors independently to include randomized control trails and retrospective studies that compared TA embolization and TL embolization in patients who developed type II endoleak after EVAR.The technical and clinical success rates were metaanalyzed with random effect model.Results A total of 6 articles with 268 patients and 290 type II endoleaks were included.The pooled odds ratio(OR)of technical success rate for TA vs.TL was 0.56(95%C7,0.10-3.18;P=0.51)and the pooled OR of clinical success rate for TA vs.TL was 0.31(95%CI,0.07-1.29;P=0.11).As a limitation,6 articles were all retrospective studies which may lead to bias.Conclusion Both TA.andTL could be eflective procedure of embolizations to resolve the type II endoleak.The metaanalysis result indicated that TA embolization was not inferior toTL embolization in technical success and clinical success.展开更多
TGF-β is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repai...TGF-β is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repair. A rabbit radial bone defect model was used to evaluate the effect of TGF-β, which was extracted and purified from bovine blood platelets, on the healing of a large segmental osteoperiosteal defect. A 1. 5-centimeter segmental defect was created in the mid-upper part of the radial shaft of adult rabbits. The defect was filled with implant containing TGF-β that consisted of carrier and bovine TGF-β. Limbs served as controls received carrier alone. The defectswere examined radiographically and histologically at 4, 8,12 , 16 and 20 weeks after implantation. The results showed that in TGF-β implant group . the defect areas at 12 weeks post operation were bridged by uniform new bone and the cut ends of cortex could not be seen;while in control group, the defects remained clear. Only a small amount of new bone formed as a cap on the cut bone ends. In the experimental group, new lamellar and woven bone formed in continuity with the cut ends of the cortex. An early medullar canal appears to be forming and contained normal-appearancing marrow elements; while the control group displayed entirely fibrous tissue within the defect site. Remnants of the cancellous bone carrier were observed in the control specimen. These data demonstrate that exogenous TGF-β initiate osteogenesis and stimulate the bone defects repair in animal model.展开更多
基金Sponsored bythe National Natural Science Foundation of China(70671009)the Postgraduate Science and Innovation Project of Beijing Instituteof Technology (GC200818)
文摘The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short （less than some critical value） do not result in system failure, and such a repair interval is omitted from the downtime record. Usually, the underlying process is Markov process if the durations of working and repair time have the negative-exponential distributions, but the new system has not the Markov properties, which is worth to study. The reliability indexes such as instantaneous availability and steady-state availabilities for the new system are given through probability analysis. A numerical example is given to illustrate the results.
基金supported by Advanced Technique Research of Valvular Heart Disease Treatment Project(2015C03028)Role of TPP1 in anti-senescence and functional optimization of aged mesenchymal stem cells(81570233)+1 种基金Role of FAIM in survival and functional improvement for aged mesenchymal stem cells(81770253)Zhejiang Clinical Research Center for Cardiovascular and Cerebrovascular Disease(2018E50002)
文摘BACKGROUND:MAVERIC(Mitral Valve Repair Clinical Trial)validates the safety and effi cacy of the ARTO system.We here report the fi rst two successful cases of utilizing the ARTO system in patients with symptomatic heart failure(HF)with functional mitral regurgitation(FMR)in Asia.METHODS:Two patients,aged 70 and 63,had severe HF with FMR.Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50%with severe mitral regurgitation(MR)in both patients.Optimizing drug treatment could not mitigate their symptoms.Therefore,we used the ARTO system to repair the mitral valve for these patients on March 5 and 6,2019,respectively.RESULTS:Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients.MR was decreased immediately after the procedures in both patients.The 30-day and 3-month transthoracic echocardiography(TTE)revealed a moderate to severe MR in both patients,and the New York Heart Association(NYHA)scales were also partially improved.CONCLUSION:The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR,and the patient selection appears to be crucial.
基金Supported by the Nature Science Foundation of Henan Education Committee(2008A110022)
文摘In this paper,the solution of a parallel redundant repairable system is investigated.by using the method of functional analysis.Especially,the linear semigroups of operator theory on Banach space,we prove the existence of the strictly dominant eigenvalue,and show the linear stability of solution.
基金Supported by the National Education Ministry for Chinese University Excellent Teachers (No.Y02012011001001) and the Academic and Technical Leader Training Foundation of Sichuan Province (No.Y02001011001003)
文摘This paper considers a two–unit same cold standby repairable system with a replaceable repair facility and delay repair .The failure time of unit is assumed to follow exponential distribution , and the repair time and delay time of failed unit are assumed to follow arbitrary distributions , whereas the failure and replacement time distributions of the repair facility are exponential and arbitrary . By using the Markov renewal process theory, some primary reliability quantities of the system are obtained.
基金supported by the National Key Research and Development Program(2019YFC1606704)the Key Research and Development Program of Shaanxi Province(2022NY-013)+1 种基金National Natural Science Foundation of China(31801653)the Natural Science Foundation of Shaanxi Province(2019JQ-722).
文摘Probiotics participate in various physiological activities and contribute to body health.However,their viability and bioefficacy are adversely affected by gastrointestinal harsh conditions,such as gastric acid,bile salts and various enzymes.Fortunately,encapsulation based on various nanomaterials shows tremendous potential to protect probiotics.In this review,we introduced some novel encapsulation technologies involving nanomaterials in view of predesigned stability and viability,selective adhesion,smart release and colonization,and efficacy exertion of encapsulated probiotics.Furthermore,the interactions between encapsulated probiotics and the gastrointestinal tract were summarized and analyzed,with highlighting the regulatory mechanisms of encapsulated probiotics on intestinal mechanical barrier,chemical barrier,biological barrier and immune barrier.This review would benefit the food and pharmaceutical industries in preparation and utilization of multifunctional encapsulated probiotics.
基金financially supported by National Natural Science Foundation of China(52374288,52204298)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001)+2 种基金National Key Research and Development Program of China(2022YFC3900805-4/7)Hunan Provincial Education Office Foundation of China(No.21B0147)Collaborative Innovation Centre for Clean and Efficient Utilization of Strategic Metal Mineral Resources,Found of State Key Laboratory of Mineral Processing(BGRIMM-KJSKL-2017-13)。
文摘Spent battery recycling has received considerable attention because of its economic and environmental potential.A large amount of retired graphite has been produced as the main electrode material,accompanied by a detailed exploration of the repair mechanism.However,they still suffer from unclear repair mechanisms and physicochemical evolution.In this study,spent graphite was repaired employing three methodologies:pickling-sintering,pyrogenic-recovery,and high-temperature sintering.Owing to the catalytic effect of the metal-based impurities and temperature control,the as-obtained samples displayed an ordered transformation,including the interlayer distance,crystalline degree,and grain size.As anodes of lithium ions batteries,the capacity of repaired samples reached up to 310 mA h g^(-1)above after 300loops at 1.0 C,similar to that of commercial graphite.Meanwhile,benefitting from the effective assembly of carbon atoms in internal structure of graphite at>1400℃,their initial coulombic efficiency were>87%.Even at 2.0 C,the capacity of samples remained approximately 244 mA h g^(-1)after 500 cycles.Detailed electrochemical and kinetic analyses revealed that a low temperature enhanced the isotropy,thereby enhancing the rate properties.Further,economic and environmental analyses revealed that the revenue obtained through suitable pyrogenic-recovering manners was approximately the largest value(5500$t^(-1)).Thus,this study is expected to clarify the in-depth effect of different repair methods on the traits of graphite,while offering all-round evaluations of repaired graphite.
基金the financial support by the Council of Scientific&Industrial Research(CSIR)-Research Scheme,India(22/0809/2019-EMR-II)。
文摘Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the effects of different patch and parent laminate stacking sequences on the enhancement of impact strength of Carbon Fiber Reinforced Polymers(CFRP)composites by utilising the adhesively bonded external patch repair technique.Damage evolution study is also performed with the aid of Acoustic Emission(AE).Two different quasi-isotropic configurations were selected for the parent laminate,viz.,[45°/45°/0°/0°]s and[45°/0°/45°/0°]s.Quasi Static Indentation(QSI)test was performed on both the pristine laminates,and damage areas were detected by using the C-scan inspection technique.Damaged laminates were repaired by using a single-sided patch of two different configurations,viz.,[45°/45°/45°/45°]and[45°/0°/0°/45°],and employing a circular plug to fill the damaged hole.Four different combinations of repaired laminates with two configurations of each parent and patch laminate were produced,which were further subjected to the QSI test.The results reveal the effectiveness of the repair method,as all the repaired laminates show higher impact resistance compared to the respective pristine laminates.Patches of[45°/0°/0°/45°]configuration when repaired by taking[45°/45°/0°/0°]s and[45°/0°/45°/0°]s as parents exhibited 68%and 73%higher peak loads,respectively,than the respective pristine laminates.Furthermore,parent and patch of configuration[45°/0°/45°/0°]s and[45°/0°/0°/45°],respectively,attain the highest peak load,whereas[45°/45°/0°/0°]s and[45°/45°/45°/45°]combinations possess the most gradual decrease in the load.
文摘This paper deals with a type of servicing machines model, which service station has a life time of the kth Er-langian distribution and can be repaired just like a new one. The cyclic time and the inefficiency quantities of this system in equilibrium are obtained.
文摘The roadway support in many places of Jiulongkou Colliery, Fengfeng Mining Bureau, such as in the Permanent transportation roadway, was failed or locally caved, which seriously affected the colliery’s coal production performance and safety. Based on analysis of supporting objects for roadway repairing, this paper proposes the supporting parameters and condruction technics. The industrial ted of 70m long roadway repairing shows that the proposed parameters and technics of bolt shotcrete and mesh support for roadway repairing are reasouable, bring good technical and economic results for the colliery, and the repairing is successful.
基金the Foundation of Key Discipline Construction of Zhejiang Province for Traditional Chinese Medicine (2017-XK-A36)the Key Research and Development Program of Zhejiang Province (2019C03076).
文摘BACKGROUND:Fatal aortic rupture caused by esophageal foreign body(EFB),is associated with a high mortality,but can be prevented by thoracic endovascular aorta repair(TEVAR)that performed increasingly as technology improves.This study aims to investigate the cause,management and prognosis of suspected penetrating aortoesophageal foreign body injury.METHODS:Twelve cases who met the criteria were enrolled in this study.The demographic and clinical data were reviewed for evaluating the characteristics of EFB.RESULTS:Among 12 cases enrolled,7 were males and 5 were females,with an age 27–86 years.The distance of EFB from aorta(DFA)of 7 cases were less than or equal to 0 mm,5 cases were 0–2 mm.Eleven cases were managed with TEVAR,only one case was with open surgery standby but finally treated by flexible endoscopy(FE)successfully,without TEVAR.In group with TEVAR,EFB of 7 cases were successfully removed by rigid endoscopy(RE),and one of them was failed at the first RE treatment.EFB of 2 cases were successfully removed by open surgery with TEVAR,and other 9 cases were managed by endoscopies with TEVAR.The mean length of stay of hospitalization(LOS)and length of ICU stay of patients treated by open surgery with TEVAR(18.50±2.12 days and 5.50±0.71 days)was significantly longer than those of patients treated by endoscopy with TEVAR(7.00±2.74 days and 1.33±1.12 days,P<0.001 and P=0.001,respectively).Five cases had severe complications.CONCLUSION:Rational application of TEVAR can be a life-saving management for aortoesophageal foreign body injury,and jointed with endoscopy is safe and effective with a shorter length of ICU or total hospital stay.
基金supported by the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060 and 61927805)the Shenzhen Fundamental Research Program(JCYJ20190813152616459).
文摘Bone defects caused by trauma,tumor,or osteoarthritis remain challenging due to the lack of effective treatments in clinic.Stem cell transplantation has emerged as an alternative approach for bone repair and attracted widespread attention owing to its excellent biological activities and therapy effect.The attempts to develop this therapeutic approach focus on the generation of effective cell delivery vehicles,since the shortcomings of direct injection of stem cells into target tissues.Here,we developed a novel core-shell microcapsule with a stem cell-laden core and a biomass shell by using all-aqueous phase microfluidic electrospray technology.The designed core-shell microcapsules showed a high cell viability during the culture procedure.In addition,the animal experiments exhibited that stem cell-laden core-shell microcapsules have good biocompatibility and therapeutic effect for bone defects.This study indicated that the core-shell biomass microcapsules generated by microfluidic electrospray have promising potential in tissue engineering and regenerative medicine.
基金supported by the projects of the National Key R&D Program of China(2016YFB0100302)the National Natural Science Foundation of China(Grant No.60306011).
文摘Iron hexacyanoferrate(FeHCF)is a promising cathode material for sodium-ion batteries.However,FeHCF always suffers from a poor cycling stability,which is closely related to the abundant vacancy defects in its framework.Herein,post-synthetic and in-situ vacancy repairing strategies are proposed for the synthesis of highquality FeHCF in a highly concentrated Na_(4)Fe(CN)_(6) solution.Both the post-synthetic and in-situ vacancy repaired FeHCF products(FeHCF-P and FeHCF-I)show the significant decrease in the number of vacancy defects and the reinforced structure,which can suppress the side reactions and activate the capacity from low-spin Fe in FeHCF.In particular,FeHCF-P delivers a reversible discharge capacity of 131 mAh g^(−1) at 1 C and remains 109 mAh g^(−1) after 500 cycles,with a capacity retention of 83%.FeHCF-I can deliver a high discharge capacity of 158.5 mAh g^(−1) at 1 C.Even at 10 C,the FeHCF-I electrode still maintains a discharge specific capacity of 103 mAh g^(−1) and retains 75% after 800 cycles.This work provides a new vacancy repairing strategy for the solution synthesis of high-quality FeHCF.
基金This study was supported in part by grants fi＇om the Bei- jing Natural Science Foundation （7141003） and Beijing Municipal Science ＆ Technology Commission （Z14110- 7002514014）.
文摘Objective Acute kidney injury （AKI） frequently occurs after catheter-based interventional procedures and increases mortality. However, the implications of AKI before thoracic endovascular aneurysm repair （TEVAR） of type B acute aortic dissection （AAD） remain unclear. This study evaluated the incidence, predictors, and in-hospital outcomes of AKI before TEVAR in patients with type B AAD. Methods Between 2009 and 2013, 76 patients were retrospectively evaluated who received TEVAR for type B AAD within 36 h from symptom onset. The patients were classified into no-AKI vs. AKI groups, and the severity of AKI was further staged according to kidney disease： im- proving global outcomes criteria before TEVAR. Results The incidence of preoperative AKI was 36.8%. In-hospital complications was significantly higher in patients with preoperative AKI compared with no-AKI （50.0% vs. 4.2%, respectively; P 〈 0.001）, including acute renal failure （21.4% vs. O, respectively; P 〈 0.001）, and they increased with severity of AKI （P 〈 0.001）. The maximum levels of body tem- perature and white blood cell count were significantly related to maximum serum creatinine level before TEVAR. Multivariate analysis showed that systolic blood pressure on admission （OR： 1.023; 95% CI： 1.003-1.044; P ： 0.0238） and bilateral renal artery involvement （OR： 19.076; 95% CI： 1.914 190.164; P = 0.0120） were strong predictors of preoperative AKI. Conclusions Preoperative AKI frequently occurred in patients with type B AAD, and correlated with higher in-hospital complications and enhanced inflammatory reaction. Systolic blood pressure on admission and bilateral renal artery involvement were major risk factors for AKI before TEVAR.
文摘Wound healing,tissue repair and regenerative medicine are in great demand,and great achievements in these fields have been made.The traditional strategy of tissue repair and regeneration has focused on the level of tissues and organs directly;however,the basic process of repair at the cell level is often neglected.Because the cell is the basic unit of organism structure and function;cell damage is caused first by ischemia or ischemia-reperfusion after severe trauma and injury.Then,damage to tissues and organs occurs with massive cell damage,apoptosis and even cell death.Thus,how to achieve the aim of perfect repair and regeneration?The basic process of tissue or organ repair and regeneration should involve repair of cells first,then tissues and organs.In this manuscript,it is my consideration about how to repair the cell first,then regenerate the tissues and organs.
文摘A new reliability allocation model has been built for engine system, which is a repairable system, and consists of a large number of mechanical components. The cost and reliability are taken as objective function and constraint condition respectively. The parameters of components lifetime distribution are given as decision variables, and the component lifetimes are assumed to follow that Weibull distribution. The allocation is separated into two steps to reduce calculated amount of one allocation. Genetic algorithm and Monte Carlo method are applied to solve distribution parameters and system cost separately.
文摘Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.
文摘Objective Type II endoleak is the most common subtype of endoleak as a complication after endovascular aneurysm repair(EVAR).The efficacy of transarterial(TA)embolization and translumber(TL)embolization in the management of type II endoleak remains equipoise.The aim of this study is to compare the technical and clinical success between TA embolization andTL embolization for type II endoleak after EVAR.Methods The protocol was registered(CRD 42018114453)and the electronic databases(Pubmed,Embase,Web of Science,and Cochrane)were systematically searched till March 2019.The search terms included EVAR,type II endoleak,and embolization.The articles were read and extracted by two authors independently to include randomized control trails and retrospective studies that compared TA embolization and TL embolization in patients who developed type II endoleak after EVAR.The technical and clinical success rates were metaanalyzed with random effect model.Results A total of 6 articles with 268 patients and 290 type II endoleaks were included.The pooled odds ratio(OR)of technical success rate for TA vs.TL was 0.56(95%C7,0.10-3.18;P=0.51)and the pooled OR of clinical success rate for TA vs.TL was 0.31(95%CI,0.07-1.29;P=0.11).As a limitation,6 articles were all retrospective studies which may lead to bias.Conclusion Both TA.andTL could be eflective procedure of embolizations to resolve the type II endoleak.The metaanalysis result indicated that TA embolization was not inferior toTL embolization in technical success and clinical success.
文摘TGF-β is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repair. A rabbit radial bone defect model was used to evaluate the effect of TGF-β, which was extracted and purified from bovine blood platelets, on the healing of a large segmental osteoperiosteal defect. A 1. 5-centimeter segmental defect was created in the mid-upper part of the radial shaft of adult rabbits. The defect was filled with implant containing TGF-β that consisted of carrier and bovine TGF-β. Limbs served as controls received carrier alone. The defectswere examined radiographically and histologically at 4, 8,12 , 16 and 20 weeks after implantation. The results showed that in TGF-β implant group . the defect areas at 12 weeks post operation were bridged by uniform new bone and the cut ends of cortex could not be seen;while in control group, the defects remained clear. Only a small amount of new bone formed as a cap on the cut bone ends. In the experimental group, new lamellar and woven bone formed in continuity with the cut ends of the cortex. An early medullar canal appears to be forming and contained normal-appearancing marrow elements; while the control group displayed entirely fibrous tissue within the defect site. Remnants of the cancellous bone carrier were observed in the control specimen. These data demonstrate that exogenous TGF-β initiate osteogenesis and stimulate the bone defects repair in animal model.
