Urea synthesis through the simultaneous electrocatalytic reduction of N_(2)and CO_(2)molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production,in which the devel...Urea synthesis through the simultaneous electrocatalytic reduction of N_(2)and CO_(2)molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production,in which the development of stable,highly efficient,and highly selective catalysts to boost the chemisorption,activation,and coupling of inert N_(2)and CO_(2)molecules remains rather challenging.Herein,by means of density functional theory computations,we proposed a new class of two-dimensional nanomaterials,namely,transition-metal phosphide monolayers(TM_(2)P,TM=Ti,Fe,Zr,Mo,and W),as the potential electrocatalysts for urea production.Our results showed that these TM_(2)P materials exhibit outstanding stability and excellent metallic properties.Interestingly,the Mo_(2)P monolayer was screened out as the best catalyst for urea synthesis due to its small kinetic energy barrier(0.35 eV)for C-N coupling,low limiting potential(-0.39 V),and significant suppressing effects on the competing side reactions.The outstanding catalytic activity of the Mo_(2)P monolayer can be ascribed to its optimal adsorption strength with the key^(*)NCON species due to its moderate positive charges on the Mo active sites.Our findings not only propose a novel catalyst with high-efficiency and high-selectivity for urea production but also further widen the potential applications of metal phosphides in electrocatalysis.展开更多
China is confronting aggravated ozone(O_(3))pollution,leading to adverse health impacts.This study quantifies the regional contributions to O_(3)in China using two approaches;estimating(1)where goods are produced(the ...China is confronting aggravated ozone(O_(3))pollution,leading to adverse health impacts.This study quantifies the regional contributions to O_(3)in China using two approaches;estimating(1)where goods are produced(the production method),and(2)where goods are consumed(the consumption method).The production method predicts higher local source contribution than the consumption method;this difference can be attributed to exports.Occurrence of high-O_(3)episodes suggests a major contribution to O_(3)concentration as a result of trade activities.Based on the consumption method,9219 out of 18532 daily premature mortalities were caused by local sources in north China,while it increased to 14471 of the production method when neglecting contributions due to export and consumption in other regions.This study suggests that O_(3)control should consider both where goods are consumed and emissions are emitted,especially taking account of international trade activities.展开更多
Objective:In robot-assisted minimally invasive surgery,proper port positioning ensures that surgical tools have adequate access to the surgical site and avoids mid-surgery collisions of robotic arms.To date,several gu...Objective:In robot-assisted minimally invasive surgery,proper port positioning ensures that surgical tools have adequate access to the surgical site and avoids mid-surgery collisions of robotic arms.To date,several guidelines have been proposed for more accurate port placement.However,challenges remain due to variations in patient morphology,anatomy,and,in particular,organ displacement due to insuf-flation in certain laparoscopic procedures.The objective of this study was to design and develop a de-cision aid for optimal port placement in robot-assisted hysterectomy that accounts for patient variability and organ displacement due to insufflation.Methods:Three components were constructed:a robot model,a patient-specific model,and an opti-mization algorithm.The three components were integrated,and the system was verified using four different patients who underwent robotic hysterectomy.Once verified,two expert surgeons were asked to evaluate the decision aid for face and construct validity.A usability test was conducted using a torso phantom with target organs located in three different locations.Two expert surgeons performed a simulated hysterectomy task with and without the decision aid to evaluate performance and satisfaction.Results:The optimization algorithm was sensitive to individual differences in anatomy in the four pa-tients.Expert surgeons successfully established face and construct validity.Usability test results showed a 28%-40% reduction in time to task completion with the optimized ports compared to expert-determined port locations without using the decision aid.Conclusions:The decision aid,based on an individualized patient-specific model,robot model,and optimization algorithm,was shown to be effective at addressing the challenges of displaced organs due to insufflation in robot-assisted hysterectomy.The face and construct validity of the decision aid was established by expert surgeons,while efficiency gains in task performance were demonstrated experimentally.展开更多
Dear Colleagues,The International Council of Ophthalmology (ICO) is deeply committed to the health and safety of our communities during the COVID-19 pandemic.Unfortunately,due to escalating risks,a physical meeting of...Dear Colleagues,The International Council of Ophthalmology (ICO) is deeply committed to the health and safety of our communities during the COVID-19 pandemic.Unfortunately,due to escalating risks,a physical meeting of our international colleagues and partners at the World Ophthalmology Congress (WOC2020) in Cape Town 26-29 June,is no longer possible.While we are all disappointed that our face-to-face meeting is cancelled,the ICO remains devoted to bringing together the world’s ophthalmologists to learn the latest from one another,and to advance eye care during these extraordinarily challenging times.展开更多
AIM： To shed some light on the relationship between anti-apoptotic serum Bcl-2 concentrations and metabolic status, anthropometric parameters, inflammation indi- ces, and non-alcoholic fatty liver disease severity we...AIM： To shed some light on the relationship between anti-apoptotic serum Bcl-2 concentrations and metabolic status, anthropometric parameters, inflammation indi- ces, and non-alcoholic fatty liver disease severity were investigated in 43 young individuals with fatty liver （FL） and 41 with nonalcoholic steatohepatitis （NASH）. METHODS： Circulating levels of Bcl-2 were detected in 84 patients with ultrasonographic findings of ＂bright liver＂ and/or hyper-transaminasemia of unknown origin and/or increase in T-glutamyl-transpeptidase （T-GT） strictly in the absence of other acute or chronic liver disease, whose age was not advanced, who gave consent to liver biopsy and were then divided on the basis of the histological results into two groups （43 with FL and 41 with NASH）. Twenty lean subjects, apparently healthy and young, were chosen as controls.RESULTS： Serum Bcl-2 concentrations were significantly higher in the FL group than in the NASH group. Insulin resistance and γ-GT activity were significantly higher in NASH subjects. Apoptotic hepatocytes were significantly more numerous in NASH patients. NASH patients presented with larger spleens and augmented C-reactive protein （CRP） concentrations than healthy subjects. Steatosis grade at histology was similar in both NASH and FL populations. The number of apoptotic cells was significantly related to anti-apoptotic Bcl-2 protein values in FL patients. Bcl-2 serum levels positively correlated to body mass index （BMI） values （P ~ 0.0001） but not to age of the population. Triglycerides/HDL ratio correlated well to waist circumference in males （P = 0.0008）. γ-GT activity was associated with homeostatic metabolic assessment （HOMA） （P = 0.0003） and with serum ferritin （P = 0.02）. Bcl-2 concentrations were not related to either spleen size or CRP values. NASH patients pre- sented a weak negative correlation between Iobular inflammation and Bcl-2 levels. A prediction by low values of serum Bcl-2 towards a greater presence of metabolically unhealthy overweight/obese patients （MUOs） was evidenced. HOMA, BMI and uric acid, in that sequence, best predicted serum Bcl-2 concentrations. CONCLUSION： IvlUOs could be detected by Bcl-2 levels. By favoring the life span of hepatocytes, and enhancing triglyceride formation, the anti-apoptotic process inhibits free fatty acids toxicity in FL.展开更多
基金financially supported in China by Natural Science Funds for Distinguished Young Scholars of Heilongjiang Province(No.JC2018004)Natural Science Foundation of Heilongjiang Province of China(No.TD2020B001)in the USA by NSF-CREST Center for Innovation,Research,and Education in Environmental Nanotechnology(CIRE2N)(No.HRD-1736093)
文摘Urea synthesis through the simultaneous electrocatalytic reduction of N_(2)and CO_(2)molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production,in which the development of stable,highly efficient,and highly selective catalysts to boost the chemisorption,activation,and coupling of inert N_(2)and CO_(2)molecules remains rather challenging.Herein,by means of density functional theory computations,we proposed a new class of two-dimensional nanomaterials,namely,transition-metal phosphide monolayers(TM_(2)P,TM=Ti,Fe,Zr,Mo,and W),as the potential electrocatalysts for urea production.Our results showed that these TM_(2)P materials exhibit outstanding stability and excellent metallic properties.Interestingly,the Mo_(2)P monolayer was screened out as the best catalyst for urea synthesis due to its small kinetic energy barrier(0.35 eV)for C-N coupling,low limiting potential(-0.39 V),and significant suppressing effects on the competing side reactions.The outstanding catalytic activity of the Mo_(2)P monolayer can be ascribed to its optimal adsorption strength with the key^(*)NCON species due to its moderate positive charges on the Mo active sites.Our findings not only propose a novel catalyst with high-efficiency and high-selectivity for urea production but also further widen the potential applications of metal phosphides in electrocatalysis.
基金This work was supported by the National Key R&D Program of China[grant number 2022YFC370110]the National Natural Science Foundation of China[grant numbers 42077194,42061134008,and 42377098]+1 种基金the Shanghai International Science and Technology Partnership Project[grant number 21230780200]the Shanghai General Project[grant number 23ZR1406100].
基金supported by the co-fund Deutsche Forschungsgemeinschaft(DFG)–National Natural Science Foundation of China(NSFC)Sino–German Air Changes project(448720203)National Natural Science Foundation of China(42077194/42061134008)Shanghai International Science and Technology Partnership Project(21230780200)。
文摘China is confronting aggravated ozone(O_(3))pollution,leading to adverse health impacts.This study quantifies the regional contributions to O_(3)in China using two approaches;estimating(1)where goods are produced(the production method),and(2)where goods are consumed(the consumption method).The production method predicts higher local source contribution than the consumption method;this difference can be attributed to exports.Occurrence of high-O_(3)episodes suggests a major contribution to O_(3)concentration as a result of trade activities.Based on the consumption method,9219 out of 18532 daily premature mortalities were caused by local sources in north China,while it increased to 14471 of the production method when neglecting contributions due to export and consumption in other regions.This study suggests that O_(3)control should consider both where goods are consumed and emissions are emitted,especially taking account of international trade activities.
文摘Objective:In robot-assisted minimally invasive surgery,proper port positioning ensures that surgical tools have adequate access to the surgical site and avoids mid-surgery collisions of robotic arms.To date,several guidelines have been proposed for more accurate port placement.However,challenges remain due to variations in patient morphology,anatomy,and,in particular,organ displacement due to insuf-flation in certain laparoscopic procedures.The objective of this study was to design and develop a de-cision aid for optimal port placement in robot-assisted hysterectomy that accounts for patient variability and organ displacement due to insufflation.Methods:Three components were constructed:a robot model,a patient-specific model,and an opti-mization algorithm.The three components were integrated,and the system was verified using four different patients who underwent robotic hysterectomy.Once verified,two expert surgeons were asked to evaluate the decision aid for face and construct validity.A usability test was conducted using a torso phantom with target organs located in three different locations.Two expert surgeons performed a simulated hysterectomy task with and without the decision aid to evaluate performance and satisfaction.Results:The optimization algorithm was sensitive to individual differences in anatomy in the four pa-tients.Expert surgeons successfully established face and construct validity.Usability test results showed a 28%-40% reduction in time to task completion with the optimized ports compared to expert-determined port locations without using the decision aid.Conclusions:The decision aid,based on an individualized patient-specific model,robot model,and optimization algorithm,was shown to be effective at addressing the challenges of displaced organs due to insufflation in robot-assisted hysterectomy.The face and construct validity of the decision aid was established by expert surgeons,while efficiency gains in task performance were demonstrated experimentally.
文摘Dear Colleagues,The International Council of Ophthalmology (ICO) is deeply committed to the health and safety of our communities during the COVID-19 pandemic.Unfortunately,due to escalating risks,a physical meeting of our international colleagues and partners at the World Ophthalmology Congress (WOC2020) in Cape Town 26-29 June,is no longer possible.While we are all disappointed that our face-to-face meeting is cancelled,the ICO remains devoted to bringing together the world’s ophthalmologists to learn the latest from one another,and to advance eye care during these extraordinarily challenging times.
文摘AIM： To shed some light on the relationship between anti-apoptotic serum Bcl-2 concentrations and metabolic status, anthropometric parameters, inflammation indi- ces, and non-alcoholic fatty liver disease severity were investigated in 43 young individuals with fatty liver （FL） and 41 with nonalcoholic steatohepatitis （NASH）. METHODS： Circulating levels of Bcl-2 were detected in 84 patients with ultrasonographic findings of ＂bright liver＂ and/or hyper-transaminasemia of unknown origin and/or increase in T-glutamyl-transpeptidase （T-GT） strictly in the absence of other acute or chronic liver disease, whose age was not advanced, who gave consent to liver biopsy and were then divided on the basis of the histological results into two groups （43 with FL and 41 with NASH）. Twenty lean subjects, apparently healthy and young, were chosen as controls.RESULTS： Serum Bcl-2 concentrations were significantly higher in the FL group than in the NASH group. Insulin resistance and γ-GT activity were significantly higher in NASH subjects. Apoptotic hepatocytes were significantly more numerous in NASH patients. NASH patients presented with larger spleens and augmented C-reactive protein （CRP） concentrations than healthy subjects. Steatosis grade at histology was similar in both NASH and FL populations. The number of apoptotic cells was significantly related to anti-apoptotic Bcl-2 protein values in FL patients. Bcl-2 serum levels positively correlated to body mass index （BMI） values （P ~ 0.0001） but not to age of the population. Triglycerides/HDL ratio correlated well to waist circumference in males （P = 0.0008）. γ-GT activity was associated with homeostatic metabolic assessment （HOMA） （P = 0.0003） and with serum ferritin （P = 0.02）. Bcl-2 concentrations were not related to either spleen size or CRP values. NASH patients pre- sented a weak negative correlation between Iobular inflammation and Bcl-2 levels. A prediction by low values of serum Bcl-2 towards a greater presence of metabolically unhealthy overweight/obese patients （MUOs） was evidenced. HOMA, BMI and uric acid, in that sequence, best predicted serum Bcl-2 concentrations. CONCLUSION： IvlUOs could be detected by Bcl-2 levels. By favoring the life span of hepatocytes, and enhancing triglyceride formation, the anti-apoptotic process inhibits free fatty acids toxicity in FL.
