Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and aerospace.They undergo extensive cutting or machining while making products out of...Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and aerospace.They undergo extensive cutting or machining while making products out of them.Dry cutting,a sustainable machining method,causes more friction and adhesion at the tool-chip interface.One of the promising solutions to this problem is cutting tool surface texturing,which can reduce tool wear and friction in dry cutting and improve machining performance.This paper aims to investigate the impact of dimple textures(made on the flank face of cutting inserts)on tool wear and chip morphology in the dry machining of AZ31B magnesium alloy.The results show that the cutting speed was the most significant factor affecting tool flank wear,followed by feed rate and cutting depth.The tool wear mechanism was examined using scanning electron microscope(SEM)images and energy dispersive X-ray spectroscopy(EDS)analysis reports,which showed that at low cutting speed,the main wear mechanism was abrasion,while at high speed,it was adhesion.The chips are discontinuous at low cutting speeds,while continuous at high cutting speeds.The dimple textured flank face cutting tools facilitate the dry machining of AZ31B magnesium alloy and contribute to ecological benefits.展开更多
Squeeze casting is a well-established and reliable process for fabricating high-integrity metallic alloys,bimetals,and composites.The quality and high performance of squeeze cast components are dependent on optimum ca...Squeeze casting is a well-established and reliable process for fabricating high-integrity metallic alloys,bimetals,and composites.The quality and high performance of squeeze cast components are dependent on optimum casting conditions.Inappropriate selection of parameter values may adversely affect the quality of the casting.The squeeze cast components are generally subjected to secondary processing such as heat treatment,extrusion,and other bulk deformation processes to improve the microstructural features and mechanical properties.Heat treatment further refines the grains and reduces porosity,consequently improving tensile strength,and hardness;however,ductility decreases.This paper provides a comprehensive review on studies concerning the influence of processing parameters on porosity,density,percentage elongation,strength,hardness,wear,and fracture of squeeze casting alloys,aiming to provide sufficient information on the squeeze casting process and the effects of processing parameters on product quality.展开更多
Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not ...Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not achieve biliary or pancreatic drainage in cases with altered anatomy or with tumors obstructing access to the duodenum. In the past those failures were typically managed exclusively by percutaneous approaches by interventional radiologists or surgical intervention. The morbidity associated was significant especially in those patients with advanced malignancy, seeking minimally invasive interventions and improved quality of life. With the advent of biliary drainage via endoscopic ultrasound (EUS) guidance, EUS guided biliary drainage has been used more frequently within the last decade in different countries. As with any novel advanced endoscopic procedure that encompasses various approaches, advanced endoscopists all over the world have innovated and adopted diverse EUS guided biliary and pancreatic drainage techniques. This diversity has resulted in variations and improvements in EUS Guided biliary and pancreatic drainage; and over the years has led to an extensive nomenclature. The diversity of techniques, nomenclature and recent progress in our intrumentation has led to a dedicated meeting on May 7 th , 2011 during Digestive Disease Week 2011. More than 40 advanced endoscopists from United States, Brazil, Mexico, Venezuela, Colombia, Italy, France, Austria, Germany, Spain, Japan, China, South Korea and India attended this pivotal meeting. The meeting covered improved EUS guided biliary access and drainage procedures, terminology, nomenclature, training and credentialing; as well as emerging devices for EUS guided biliary drainage. This paper summarizes the meeting's agenda and the conclusions generated by the creation of this consortium group.展开更多
Acute kidney injury(AKI)in cirrhosis,including hepatorenal syndrome(HRS),is a common and serious complication in cirrhotic patients,leading to significant morbidity and mortality.AKI is separated into two categories,n...Acute kidney injury(AKI)in cirrhosis,including hepatorenal syndrome(HRS),is a common and serious complication in cirrhotic patients,leading to significant morbidity and mortality.AKI is separated into two categories,non-HRS AKI and HRS-AKI.The most recent definition and diagnostic criteria of AKI in cirrhosis and HRS have helped diagnose and prognosticate the disease.The pathophysiology behind non-HRS-AKI and HRS is more complicated than once theorized and involves more processes than just splanchnic vasodilation.The common biomarkers clinicians use to assess kidney injury have significant limitations in cirrhosis patients;novel biomarkers being studied have shown promise but require further studies in clinical settings and animal models.The overall management of non-HRS AKI and HRS-AKI requires a systematic approach.Although pharmacological treatments have shown mortality benefit,the ideal HRS treatment option is liver transplantation with or without simultaneous kidney transplantation.Further research is required to optimize pharmacologic and nonpharmacologic approaches to treatment.This article reviews the current guidelines and recommendations of AKI in cirrhosis.展开更多
The coronavirus disease 2019(COVID-19)has caused one of the worst public health crises in modern history.Even though severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory tract,gastrointest...The coronavirus disease 2019(COVID-19)has caused one of the worst public health crises in modern history.Even though severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory tract,gastrointestinal manifestations are well described in literature.This review will discuss the epidemiology,virology,manifestations,immunosuppressant states,and lessons learned from COVID-19.Observations:At the time of writing,COVID-19 had infected more than 111 million people and caused over 2.5 million deaths worldwide.Multiple medical comorbidities including obesity,pre-existing liver condition and the use of proton pump inhibitor have been described as risk factor for severe COVID-19.COVID-19 most frequently causes diarrhea(12.4%),nausea/vomiting(9%)and elevation in liver enzymes(15%-20%).The current data does not suggest that patients on immunomodulators have a significantly increased risk of mortality from COVID-19.The current guidelines from American Gastroenterological Association and American Association for the Study of Liver Diseases do not recommend pre-emptive changes in patients on immunosuppression if the patients have not been infected with COVID-19.Conclusions and relevance:The COVID-19 pandemic has prompted a change in structure and shape of gastroenterology departmental activities.Endoscopy should be performed only when necessary and with strict protective measures.Online consultations in the form of telehealth services and home drug deliveries have revolutionized the field.展开更多
In the present work,an attempt is made to partially replace high cost silica sand with sustainable eco-friendly cow-dung.The practical utility of cow dung as an additive material that facilitates binding in sand mould...In the present work,an attempt is made to partially replace high cost silica sand with sustainable eco-friendly cow-dung.The practical utility of cow dung as an additive material that facilitates binding in sand moulds has been tested.The Taguchi method is used to plan and conduct nine experiments with three replicates each.Pareto analysis of variance study is performed to understand the practical significance of moulding sand variables,that is,percentage of cow dung,clay,water,and degree of ramming on sand mould properties.The conflicting multiple objective functions(maximize mould hardness,and minimize collapsibility and gas evolution)are optimized by utilizing the Data Envelopment Analysis Ranking(DEAR)method.The optimal parameters i.e.6%of clay,4%of water,5%of cow-dung and 4 numbers of ramming strokes are obtained by applying a hybrid Taguchi-DEAR method.These parameters show the best moulding properties are:mould hardness 55,gas evolution 5.9 ml·g-1,and collapsibility 470 g·cm-2.Thereafter,a Lovejoy coupling made of aluminium is cast in the sand mould prepared with cow dung and without cow dung,with the optimum set of parameters.The mechanical properties,surface finish,and microstructure of the casting cast with cow-dung are better than that without cowdung.展开更多
Soybean(Glycine max(L.)Merr)is an agro-economic crop growing across the world to cater nutrition for both human and animal feed due to the high oil and protein content in its edible seeds.The genes and QTLs associated...Soybean(Glycine max(L.)Merr)is an agro-economic crop growing across the world to cater nutrition for both human and animal feed due to the high oil and protein content in its edible seeds.The genes and QTLs associated with important agronomic traits in this crop have already been identified and validated for soybean cyst nematode(SCN),Phytophthora root and stem rot,Pythium root rot and aphid resistance,seed quality,nutrient values,and also employed for genetic improvement in soybean.In the last decade,micro RNAs(miRNAs)have been considered the effector molecules,so the detection and characterization of novel miRNAs in soybean have been taken up by several workers.The advancement in the strategy of sequencing and tools of bioinformatics during last decade has contributed to the discovery of many soybean miRNAs,thus miRNA can be used as a tool in molecular breeding studies,and this has opened new vistas for miRNA mediated genetic improvement of soybean to augment crop productivity as well as nutritional quality.This review addresses the current state of understanding of miRNAmediated stress responses,nutrient acquisition,plant development and crop production processes in soybean.展开更多
Dear Editor,The Coronavirus disease 2019(COVID-19)pandemic has caused over 670 million cases and 6.7 million deaths worldwide,many of which are attributed to cardiovascular complications.Virus-induced endothelial dama...Dear Editor,The Coronavirus disease 2019(COVID-19)pandemic has caused over 670 million cases and 6.7 million deaths worldwide,many of which are attributed to cardiovascular complications.Virus-induced endothelial damage,endothelial barrier dysfunction,thrombosis,and cytokine storm are implicated in heart and multi-organ failure.展开更多
文摘Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and aerospace.They undergo extensive cutting or machining while making products out of them.Dry cutting,a sustainable machining method,causes more friction and adhesion at the tool-chip interface.One of the promising solutions to this problem is cutting tool surface texturing,which can reduce tool wear and friction in dry cutting and improve machining performance.This paper aims to investigate the impact of dimple textures(made on the flank face of cutting inserts)on tool wear and chip morphology in the dry machining of AZ31B magnesium alloy.The results show that the cutting speed was the most significant factor affecting tool flank wear,followed by feed rate and cutting depth.The tool wear mechanism was examined using scanning electron microscope(SEM)images and energy dispersive X-ray spectroscopy(EDS)analysis reports,which showed that at low cutting speed,the main wear mechanism was abrasion,while at high speed,it was adhesion.The chips are discontinuous at low cutting speeds,while continuous at high cutting speeds.The dimple textured flank face cutting tools facilitate the dry machining of AZ31B magnesium alloy and contribute to ecological benefits.
文摘Squeeze casting is a well-established and reliable process for fabricating high-integrity metallic alloys,bimetals,and composites.The quality and high performance of squeeze cast components are dependent on optimum casting conditions.Inappropriate selection of parameter values may adversely affect the quality of the casting.The squeeze cast components are generally subjected to secondary processing such as heat treatment,extrusion,and other bulk deformation processes to improve the microstructural features and mechanical properties.Heat treatment further refines the grains and reduces porosity,consequently improving tensile strength,and hardness;however,ductility decreases.This paper provides a comprehensive review on studies concerning the influence of processing parameters on porosity,density,percentage elongation,strength,hardness,wear,and fracture of squeeze casting alloys,aiming to provide sufficient information on the squeeze casting process and the effects of processing parameters on product quality.
文摘Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not achieve biliary or pancreatic drainage in cases with altered anatomy or with tumors obstructing access to the duodenum. In the past those failures were typically managed exclusively by percutaneous approaches by interventional radiologists or surgical intervention. The morbidity associated was significant especially in those patients with advanced malignancy, seeking minimally invasive interventions and improved quality of life. With the advent of biliary drainage via endoscopic ultrasound (EUS) guidance, EUS guided biliary drainage has been used more frequently within the last decade in different countries. As with any novel advanced endoscopic procedure that encompasses various approaches, advanced endoscopists all over the world have innovated and adopted diverse EUS guided biliary and pancreatic drainage techniques. This diversity has resulted in variations and improvements in EUS Guided biliary and pancreatic drainage; and over the years has led to an extensive nomenclature. The diversity of techniques, nomenclature and recent progress in our intrumentation has led to a dedicated meeting on May 7 th , 2011 during Digestive Disease Week 2011. More than 40 advanced endoscopists from United States, Brazil, Mexico, Venezuela, Colombia, Italy, France, Austria, Germany, Spain, Japan, China, South Korea and India attended this pivotal meeting. The meeting covered improved EUS guided biliary access and drainage procedures, terminology, nomenclature, training and credentialing; as well as emerging devices for EUS guided biliary drainage. This paper summarizes the meeting's agenda and the conclusions generated by the creation of this consortium group.
文摘Acute kidney injury(AKI)in cirrhosis,including hepatorenal syndrome(HRS),is a common and serious complication in cirrhotic patients,leading to significant morbidity and mortality.AKI is separated into two categories,non-HRS AKI and HRS-AKI.The most recent definition and diagnostic criteria of AKI in cirrhosis and HRS have helped diagnose and prognosticate the disease.The pathophysiology behind non-HRS-AKI and HRS is more complicated than once theorized and involves more processes than just splanchnic vasodilation.The common biomarkers clinicians use to assess kidney injury have significant limitations in cirrhosis patients;novel biomarkers being studied have shown promise but require further studies in clinical settings and animal models.The overall management of non-HRS AKI and HRS-AKI requires a systematic approach.Although pharmacological treatments have shown mortality benefit,the ideal HRS treatment option is liver transplantation with or without simultaneous kidney transplantation.Further research is required to optimize pharmacologic and nonpharmacologic approaches to treatment.This article reviews the current guidelines and recommendations of AKI in cirrhosis.
文摘The coronavirus disease 2019(COVID-19)has caused one of the worst public health crises in modern history.Even though severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory tract,gastrointestinal manifestations are well described in literature.This review will discuss the epidemiology,virology,manifestations,immunosuppressant states,and lessons learned from COVID-19.Observations:At the time of writing,COVID-19 had infected more than 111 million people and caused over 2.5 million deaths worldwide.Multiple medical comorbidities including obesity,pre-existing liver condition and the use of proton pump inhibitor have been described as risk factor for severe COVID-19.COVID-19 most frequently causes diarrhea(12.4%),nausea/vomiting(9%)and elevation in liver enzymes(15%-20%).The current data does not suggest that patients on immunomodulators have a significantly increased risk of mortality from COVID-19.The current guidelines from American Gastroenterological Association and American Association for the Study of Liver Diseases do not recommend pre-emptive changes in patients on immunosuppression if the patients have not been infected with COVID-19.Conclusions and relevance:The COVID-19 pandemic has prompted a change in structure and shape of gastroenterology departmental activities.Endoscopy should be performed only when necessary and with strict protective measures.Online consultations in the form of telehealth services and home drug deliveries have revolutionized the field.
文摘In the present work,an attempt is made to partially replace high cost silica sand with sustainable eco-friendly cow-dung.The practical utility of cow dung as an additive material that facilitates binding in sand moulds has been tested.The Taguchi method is used to plan and conduct nine experiments with three replicates each.Pareto analysis of variance study is performed to understand the practical significance of moulding sand variables,that is,percentage of cow dung,clay,water,and degree of ramming on sand mould properties.The conflicting multiple objective functions(maximize mould hardness,and minimize collapsibility and gas evolution)are optimized by utilizing the Data Envelopment Analysis Ranking(DEAR)method.The optimal parameters i.e.6%of clay,4%of water,5%of cow-dung and 4 numbers of ramming strokes are obtained by applying a hybrid Taguchi-DEAR method.These parameters show the best moulding properties are:mould hardness 55,gas evolution 5.9 ml·g-1,and collapsibility 470 g·cm-2.Thereafter,a Lovejoy coupling made of aluminium is cast in the sand mould prepared with cow dung and without cow dung,with the optimum set of parameters.The mechanical properties,surface finish,and microstructure of the casting cast with cow-dung are better than that without cowdung.
文摘Soybean(Glycine max(L.)Merr)is an agro-economic crop growing across the world to cater nutrition for both human and animal feed due to the high oil and protein content in its edible seeds.The genes and QTLs associated with important agronomic traits in this crop have already been identified and validated for soybean cyst nematode(SCN),Phytophthora root and stem rot,Pythium root rot and aphid resistance,seed quality,nutrient values,and also employed for genetic improvement in soybean.In the last decade,micro RNAs(miRNAs)have been considered the effector molecules,so the detection and characterization of novel miRNAs in soybean have been taken up by several workers.The advancement in the strategy of sequencing and tools of bioinformatics during last decade has contributed to the discovery of many soybean miRNAs,thus miRNA can be used as a tool in molecular breeding studies,and this has opened new vistas for miRNA mediated genetic improvement of soybean to augment crop productivity as well as nutritional quality.This review addresses the current state of understanding of miRNAmediated stress responses,nutrient acquisition,plant development and crop production processes in soybean.
基金This work was supported by the British Heart Foundation(BHF)project grant“Targeting the SARS-CoV-2 S-protein binding to the ACE2 receptor to preserve human cardiac pericytes function in COVID-19”(PG/20/10285)(to P.M.and E.A.)European Commission H2020 CORDIS project COVIRNA(project/id/101016072)(to C.E.and P.K.S.)BHF Chair award(CH/15/1/31199)(to C.E).In addition,it was supported by a grant from the National Institute for Health Research(NIHR)Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol.E.A.is a postdoctoral researcher supported by the Heart Research UK translational project grant“Targeting pericytes for halting pulmonary hypertension in infants with congenital heart disease”(RG2697/21/23)(to P.M.and E.A.).I.B.is an investigator of the Wellcome Trust(106115/Z/14/Z).
文摘Dear Editor,The Coronavirus disease 2019(COVID-19)pandemic has caused over 670 million cases and 6.7 million deaths worldwide,many of which are attributed to cardiovascular complications.Virus-induced endothelial damage,endothelial barrier dysfunction,thrombosis,and cytokine storm are implicated in heart and multi-organ failure.