As a young engineer in the power plant department of Brown Boveri,Dr.Schulten had the idea to design nuclear power stations without major risk.The following requirements must be accomplished:A negative temperature co...As a young engineer in the power plant department of Brown Boveri,Dr.Schulten had the idea to design nuclear power stations without major risk.The following requirements must be accomplished:A negative temperature coefficient had to avoid an MCA(Maximum Credible Accident);Ceramic materials for core construction and fuel elements;A homogenous mixture of nuclear fuel and graphite had to be able to use uranium and thorium as breeding material;The produced high temperature heat shall be the basis for production of electricity,drinking water,hydrogen,etc.;A relatively simple plant,which could be operated in developing countries,to cogenerate electricity and heat;Helium used as cooling gas.展开更多
Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the el...Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li-S redox.Herein,the high energy/high performance of a Li-S full battery with practical sulfur loading and minimum electrolyte volume is reported.A unique hybrid architecture configured with Ni-Co metal alloy(NiCo)and metal oxide(NiCoO_(2))nanoparticles heterogeneously anchored in carbon nanotube-embedded selfstanding carbon matrix is fabricated as a host for sulfur.This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li-S batteries.Through experimental and theoretical validations,the function of NiCo and NiCoO_(2) nanoparticles as an efficient polysulfide mediator is established.These particles afford polysulfide anchoring and catalytic sites for Li-S redox reaction,thus improving the redox conversion reversibility.Even at high sulfur loading,the nanostructured Ni-Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half-cell and full-cell batteries using a graphite anode.展开更多
To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely us...To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin.展开更多
SaaS（软件即服务）和Cloud Computing（云计算）是目前IT行业的趋势，在未来企业的各种应用中将发挥关键的作用，其重要性毋庸置疑。权威的市场调研公司Gartner指出，“organizations are switching from companyowned hardware and so...SaaS（软件即服务）和Cloud Computing（云计算）是目前IT行业的趋势，在未来企业的各种应用中将发挥关键的作用，其重要性毋庸置疑。权威的市场调研公司Gartner指出，“organizations are switching from companyowned hardware and software assets to per-useservice-based models”，展开更多
Primary total knee arthroplasty(TKA)is a widespread procedure to address end stage osteoarthritis with good results,clinical outcomes,and long-term survivorship.Although it is frequently performed in elderly,an increa...Primary total knee arthroplasty(TKA)is a widespread procedure to address end stage osteoarthritis with good results,clinical outcomes,and long-term survivorship.Although it is frequently performed in elderly,an increased demand in young and active people is expected in the next years.However,a considerable dissatisfaction rate has been reported by highly demanding patients due to the intrinsic limitations provided by the TKA.Bicruciate-retaining(BCR)TKA was developed to mimic knee biomechanics,through anterior cruciate ligament preservation.First-generation BCR TKA has not gained popularity due to its being a challenging technique and having poor survival outcomes.Thanks to implant design improvement and surgeon-friendly instrumentation,secondgeneration BCR TKA has seen renewed interest.This review will focus on surgical indications,kinematical basis,clinical results and latest developments of secondgeneration BCR TKA.展开更多
文摘As a young engineer in the power plant department of Brown Boveri,Dr.Schulten had the idea to design nuclear power stations without major risk.The following requirements must be accomplished:A negative temperature coefficient had to avoid an MCA(Maximum Credible Accident);Ceramic materials for core construction and fuel elements;A homogenous mixture of nuclear fuel and graphite had to be able to use uranium and thorium as breeding material;The produced high temperature heat shall be the basis for production of electricity,drinking water,hydrogen,etc.;A relatively simple plant,which could be operated in developing countries,to cogenerate electricity and heat;Helium used as cooling gas.
基金supported by the National Research Foundation of Korea (NRF)grant funded by the Korean government (MSIT) (NRF-2022R1C1C1011058)supported by the Korea Institute for Advancement of Technology (KIAT)grant funded by the Korean Government (MOTIE) (P0012748,HRD Program for Industrial Innovation).
文摘Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li-S redox.Herein,the high energy/high performance of a Li-S full battery with practical sulfur loading and minimum electrolyte volume is reported.A unique hybrid architecture configured with Ni-Co metal alloy(NiCo)and metal oxide(NiCoO_(2))nanoparticles heterogeneously anchored in carbon nanotube-embedded selfstanding carbon matrix is fabricated as a host for sulfur.This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li-S batteries.Through experimental and theoretical validations,the function of NiCo and NiCoO_(2) nanoparticles as an efficient polysulfide mediator is established.These particles afford polysulfide anchoring and catalytic sites for Li-S redox reaction,thus improving the redox conversion reversibility.Even at high sulfur loading,the nanostructured Ni-Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half-cell and full-cell batteries using a graphite anode.
文摘To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin.
文摘SaaS（软件即服务）和Cloud Computing（云计算）是目前IT行业的趋势，在未来企业的各种应用中将发挥关键的作用，其重要性毋庸置疑。权威的市场调研公司Gartner指出，“organizations are switching from companyowned hardware and software assets to per-useservice-based models”，
文摘Primary total knee arthroplasty(TKA)is a widespread procedure to address end stage osteoarthritis with good results,clinical outcomes,and long-term survivorship.Although it is frequently performed in elderly,an increased demand in young and active people is expected in the next years.However,a considerable dissatisfaction rate has been reported by highly demanding patients due to the intrinsic limitations provided by the TKA.Bicruciate-retaining(BCR)TKA was developed to mimic knee biomechanics,through anterior cruciate ligament preservation.First-generation BCR TKA has not gained popularity due to its being a challenging technique and having poor survival outcomes.Thanks to implant design improvement and surgeon-friendly instrumentation,secondgeneration BCR TKA has seen renewed interest.This review will focus on surgical indications,kinematical basis,clinical results and latest developments of secondgeneration BCR TKA.
