Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression ...Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression by non-hematopoietic cells is scarce. In the present study, gene and protein expression of this integrin subunit was characterized in proliferating and quiescent human RPE cells. Immunofluorescent studies confirm that the α4 subunit is expressed in vitro by RPE cells, a result that has been validated by immunofluorescence and FACS analyses. The accumulation of the α4 integrin at cell-cell junctions in post-confluent RPE cell cultures negatively correlated with the level of expression of the mRNA transcript. Accordingly, transient transfection analyses reveal that the α4 promoter activity is considerably reduced when RPE cells form a confluent monolayer. Moreover, transfection of recombinant constructs bearing 5’-deletions of the α4 promoter segment allows the localization of strong negative regulatory elements on the -76 to -300 region of the α4 gene suggesting that its expression is intimately linked to the proliferative state of primary cultured RPE cells.展开更多
The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion an...The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion and damage during the growth stage,which brings serious problems to the restoration of grass in the early stage.Therefore,effects of coir geotextile and geocell on EG erosion under four confluence intensities were researched in this study.Results of the simulated water discharge erosion test showed that when the confluence strength was less than 30 L/min,geocell and coir geotextile had a good effect on controlling EG erosion,and sediment yield of geocell and coir geotextile was reduced by 25.95%–37.82%and 73.73%–88.96%,respectively.However,when confluence intensity increased to 40 L/min,protective effect of coir geotextile decreased,and sediment yield rate increased sharply by 189.03%.When confluence intensity increased to 50 L/min,the protective effect of coir geotextile was lost.On the other hand,geocell showed that the greater the flow rate,the better the protective effect.In addition,with the increase in confluence intensity,erosion pattern of coir geotextile developed from sheet erosion to intermittent fall and then to completion of main rill,and the protective effect was gradually weakened.In contrast,the protective effect of EG under geocell was gradually enhanced from the continuous rill to the intermittent rill and finally to the intermittent fall.This study shows that coir geotextile and geocell can prevent EG erosion,and the effect of geocell is better than that of coir geotextile on the surface of EG.展开更多
Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common.Studies of schematized co...Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common.Studies of schematized confluences with a step at the interface between the tributary and the main channel bed reveal that bed elevation discordance is an important additional control for the confluence hydrodynamics.This study aimed to improve understanding of the influence of bed elevation discordance on the flow patterns and head losses in a right-angled confluence of an open channel with rectangular cross-sections.A large eddy simulation (LES)-based numerical model was set up and validated with experiments by others.Four configurations with different bed discordance ratios were investigated.The results confirm that, with increasing bed elevation discordance, the tributary streamlines at the confluence interface deviate less from the geometrical confluence angle, the extent of the recirculation zone (RZ) gets smaller, the ratio of the water depth upstream to that downstream of the confluence decreases, and the water level depression reduces.The bed elevation discordance also leads to the development of a large-scale structure in the lee of the step.Despite the appearance of the large-scale structure, the reduced extent of the RZ and associated changes in flow deflection/contraction reduce total head losses experienced by the main channel with an increase of the bed discordance ratio.It turns out that bed elevation discordance converts the lateral momentum from the tributary to streamwise momentum in the main channel more efficiently.展开更多
Based on two-phase flow theory and shallow water flow assumption,a mathematical model is applied to simulate debris flow.The model considers a two-phase mixture of sediments and water fluid.Assuming that the sediments...Based on two-phase flow theory and shallow water flow assumption,a mathematical model is applied to simulate debris flow.The model considers a two-phase mixture of sediments and water fluid.Assuming that the sediments and the water fluid move downstream with the same velocity,the flow of the mixture is described using a two dimensional depth averaged model with a unique 2-D momentum equation and two mass balance e- quations for the mixture and the sediments,respectively.The finite volume method is used f...展开更多
Numerical simulation technology has been widely used in the foundry industry to analyze and improve casting processes.During the casting filling process,many filling-related defects form easily at the confluences of l...Numerical simulation technology has been widely used in the foundry industry to analyze and improve casting processes.During the casting filling process,many filling-related defects form easily at the confluences of liquid metal streams.The main filling-related defects are cold shut defects.To calculate the positions of casting defects,the characteristics of liquid metal confluences were analyzed.The flow front of liquid metal was captured by the volume-of-fluid algorithm to obtain a time field,which was used to calculate the time derivatives of the liquid front position and the confluences of liquid metal streams.To distinguish small confluences from the main confluences,the concept of confluent scale was developed,which was used to filter the small confluences based on a threshold.The calculation process was demonstrated through the post-processing of numerical simulation.A "W" shaped casting and a steering wheel casting were calculated to validate the accuracy of the method developed in this study.The positions of cold shut defects were predicted by calculating the confluences of liquid metal streams.The method was proved to be practical by comparing the calculation results with the positions of cold shut defects in an end cover casting.The computation of confluences and cold shut defects can improve the analysis efficiency and provide assurance for the optimization of a casting process plan.展开更多
Objective: To review our experience in and the re-sults of resecting liver tumors involving the hepatoca-val confluence under intermittent portal triad clam-ping (PTC).Methods: Sixty-eight consecutive patients with li...Objective: To review our experience in and the re-sults of resecting liver tumors involving the hepatoca-val confluence under intermittent portal triad clam-ping (PTC).Methods: Sixty-eight consecutive patients with livertumors involving the hepatocaval confluence under-went hepatectomies with liver parenchymal transec-tions under intermittent PTC.Results: All the tumors were successfully resected un-der PTC, except for one in which the infrahepatic in-ferior vena cava was concomitantly occluded in addi-tion to PTC. There was neither operative death noruncontrollable massive bleeding or air embolism oc-curred in our patients. The bleedings from the mainand short hepatic veins and right adrenal veins wereproperly managed during the operation, with a meanintraoperative blood loss of 1400 ml. Of the 68tumors resected, 65 were hepatocellular carcinomas(HCC). Their 1-, 2-, 3- and 4-year suvival rateswere 64.11%, 52. 82%, 44.90% and 36.98%, re-spectively, and the patients with HCC with capsulessurvived significantly longer than those with HCCwithout capsules.Conclusions: The liver tumors involving the hepato-caval confluence could be safely resected simply un-der PTC, without routine use of total hepatic vascu-lar exclusion. As for HCCs in this area, the tumorwith capsule is a better indicator for surgical resec-tion than that without capsule.展开更多
Using IAP-AGCM, a model developed by the institute of atmospheric research, Academia Sinica,controlled numerital expertrients on SST and east Asian circulation have been performed and some conclusions have been reache...Using IAP-AGCM, a model developed by the institute of atmospheric research, Academia Sinica,controlled numerital expertrients on SST and east Asian circulation have been performed and some conclusions have been reached as follows. The abnomality of subtropical high has a two-month remote lagging response to SSTA of the western tropical Pacific, the South China Sea and the Bay of Bengal. Theabnormality always appears in pair for the western Pacific subtrphal high and the eastern Pacific subtropical high, with the latter beginning earlier than the former. When the SST of the western trophalPacific, South China Sea and Bay of Bengal anomalously decreases (increases), the subtropical high iskept anomalously more t0 the south (north),consistently so is the location at which two zonal geopotential waves meet in the subtropical western Pacific. Under the action of the SSTA above and when ablocking pattern over east Asia continent appears, the assembling location of the joinin8 waves for thewestern Pacific is closely related to that of the blocking high, which is especially important to consistentabnormality of the subtropical high.展开更多
Also if rarely,hepatocellular carcinoma,cholangiocarcinoma,and metastatic carcinoma can invade the retrohepatic portion of the inferior vena cava(IVC),because of the proximity of this vessel to the liver.^([1]) Innova...Also if rarely,hepatocellular carcinoma,cholangiocarcinoma,and metastatic carcinoma can invade the retrohepatic portion of the inferior vena cava(IVC),because of the proximity of this vessel to the liver.^([1]) Innovative vascular exclusion techniques and new surgical resection methods,derived from improvements in liver surgery and transplantation,have allowed us展开更多
Here we investigate the ocean-atmosphere coupling and the contribution of the Sea Surface Temperature (SST) variations in: 1) Brazil-Malvinas Confluence (BMC) region, 2) Southwest Atlantic Ocean and 3) Southern Brazil...Here we investigate the ocean-atmosphere coupling and the contribution of the Sea Surface Temperature (SST) variations in: 1) Brazil-Malvinas Confluence (BMC) region, 2) Southwest Atlantic Ocean and 3) Southern Brazil. Numerical simulations of the ECHAM5/MPI-OM coupled ocean-atmosphere model were used to analyze the changes in the seasonal trajectory of the extratropical cyclones, in terms of intensification of physical mechanisms and implications for future scenarios. The numerical experiment for the future scenario considered an atmospheric CO2 concentration of approximately 770 ppm, which represents an increment of more than 350 ppm over the current values recorded by the Mauna Loa reference station. For this scenario, the results indicated a Storm Tracks (ST) displacement of 5° latitude toward south and changes of the meridional transport of sensible heat, close to 50°S. The increase in SST induces ST intensification and consequently an increase in the occurrence of extratropical cyclones. Overall, in the BMC region, we found a change in the pattern of cyclogenetic activity occurrence, with less frequent, but more intense events. On the Southern Brazilian region, the results of this study indicate increases in rainfall during summer months, whereas, a decrease in frequency and an increase in intensity were found for wintertime. We suggest that these changes could impact the climate dynamic of the Brazilian South coast, with a magnitude yet unknown.展开更多
FOSHAN is an ancient city endowed with a bountiful culture.Located in the heartland of the vibrant Pearl River Delta,Foshan is west of Guangzhou,the capital of Guangdong Province,and gazes upon Hong Kong and Macao fro...FOSHAN is an ancient city endowed with a bountiful culture.Located in the heartland of the vibrant Pearl River Delta,Foshan is west of Guangzhou,the capital of Guangdong Province,and gazes upon Hong Kong and Macao from the north.For centuries,Foshan has been the economic and trade center in this region,and known for its high-quality ceramic products throughout the country.In modern times,it has witnessed a growth展开更多
Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into r...Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.展开更多
Coalescence of traditional medicine Ayurveda and in silico technology is a rigor for supplementary development of future-ready effective traditional medicine. Ayurveda is a popular traditional medicine in South Asia, ...Coalescence of traditional medicine Ayurveda and in silico technology is a rigor for supplementary development of future-ready effective traditional medicine. Ayurveda is a popular traditional medicine in South Asia, emanating worldwide for the treatment of metabolic disorders and chronic illness. Techniques of in silico biology are not much explored for the investigation of a variety of bioactive phytochemicals of Ayurvedic herbs. Drug repurposing, reverse pharmacology, and polypharmacology in Ayurveda are areas in silico explorations that are needed to understand the rich repertoire of herbs, minerals, herbo-minerals, and assorted Ayurvedic formulations. This review emphasizes exploring the concept of Ayurveda with in silico approaches and the need for Ayurinformatics studies. It also provides an overview of in silico studies done on phytoconstituents of some important Ayurvedic plants, the utility of in silico studies in Ayurvedic phytoconstituents/formulations, limitations/challenges, and prospects of in silico studies in Ayurveda. This article discusses the convergence of in silico work, especially in the least explored field of Ayurveda. The focused coalesce of these two domains could present a predictive combinatorial platform to enhance translational research magnitude. In nutshell, it could provide new insight into an Ayurvedic drug discovery involving an in silico approach that could not only alleviate the process of traditional medicine research but also enhance its effectiveness in addressing health care.展开更多
Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This stud...Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This study aims to elucidate this impact and response mechanisms using precipitation data of a climate change-sensitive confluence zone of the southwest and southeast monsoons in Yunnan Province from 1988 to 2018.The results revealed that the precipitation pattern could be divided into three periods:abundant precipitation(Stage I,from 1988 to 2004),decreased precipitation(Stage II,from 2005 to 2015),and drought recovery(Stage III,from 2016 to 2018).Following the transition from Stage I to Stage II and from Stage II to Stage III,the area of precipitation changed significantly,accounting for 15.07%,13.87%,and 16.53%of Yunnan’s total area,for Stages I,II,and III,respectively.At the provincial level,a significant positive correlation was observed between precipitation and food production(r=0.535,P<0.01),and the correlation coefficient between precipitation and grain yield was higher than that between precipitation and meat and milk production.Based on a precipitation–grain yield transect and breakpoint detection method,key precipitation thresholds affecting grain yield were estimated as 700 and 1500 mm,respectively;when precipitation was<700,700–1500,and≥1500 mm,the correlation coefficients between precipitation and grain yield were 0.448(P<0.01),0.370(P<0.01),and–0.229(P>0.05),respectively.Based on the precipitation thresholds,Yunnan Province can be divided into precipitation surplus,precipitation equilibrium,and precipitation deficit regions,corresponding countermeasures to stabilize grain yield were proposed for each of these regions.The threshold effect of precipitation on grain yield is controlled by molecular-level water–crop mechanisms,in which reactive oxygen species,a by-product of plant aerobic metabolism,plays a key regulatory role.展开更多
Confluences act as critical nodes in a river system.They affect hydrodynamics,sediment transport,bed morphology,and eco-hydraulics of the river system.Convergence of streams produces the complex mechanism of flow mome...Confluences act as critical nodes in a river system.They affect hydrodynamics,sediment transport,bed morphology,and eco-hydraulics of the river system.Convergence of streams produces the complex mechanism of flow momentum and mass mixing which may affect the aquatic environment locally and even lasting for a long distance downstream.The confluence creates a hotspot for the river system’s ecological change,which usually leads to changes in water temperature,suspended-sediment load,bed material,nutrient concentrations,water chemistry,and organic-matter content.Hence,the dynamics of river confluences are very complex and have critical effects on river system’s water environment and ecology.For this reason,a review summarizing turbulent flow,sediment transport,morphological-dynamics,mixing processes,and their effects on the ecology of the aquatic environment at river confluences is in order.A future research agenda and opportunities pertinent to river confluence are vitally emphasized as a multidisciplinary research topic.展开更多
For the study of the effects of partially non-submerged rigid vegetation on the free-surface confluence flow in a curved open channel,a numerical simulation is carried out by using the Volume of Fluid model combined w...For the study of the effects of partially non-submerged rigid vegetation on the free-surface confluence flow in a curved open channel,a numerical simulation is carried out by using the Volume of Fluid model combined with the porous media model with the software OpenFOAM.The model is first validated by using available experimental measurement data with a good agreement.Then,the characteristics of the separation zone generated by the centrifugal forces and the confluence flow are analyzed.Due to the resistance created by the vegetation,the velocities in the separation zone are more chaotic and the separation zone becomes smaller and more irregular.The reduction of the separation zone area of the vegetated flow in the convex bank is more significant than that in the concave bank.The velocities in the vegetated region become much smaller and remains so in the downstream flow after the vegetation region.Meanwhile,the vegetation compresses and divides the circulations in the flow area,rebuilding a structure with smaller circulations in the main flow and unclear circulations in the vegetation region.In addition,the bed wall shear stresses are significantly smaller in the vegetation region and the separation zone compared to the non-vegetated flow.This implies that the vegetation can have the effect of protecting the river bed from erosion.展开更多
文摘Integrins are a family of transmembrane glycoproteins that mediate cell-cell and cell-extracellular matrix interactions. The integrin α4 subunit is widely expressed by cells from the immune system and its expression by non-hematopoietic cells is scarce. In the present study, gene and protein expression of this integrin subunit was characterized in proliferating and quiescent human RPE cells. Immunofluorescent studies confirm that the α4 subunit is expressed in vitro by RPE cells, a result that has been validated by immunofluorescence and FACS analyses. The accumulation of the α4 integrin at cell-cell junctions in post-confluent RPE cell cultures negatively correlated with the level of expression of the mRNA transcript. Accordingly, transient transfection analyses reveal that the α4 promoter activity is considerably reduced when RPE cells form a confluent monolayer. Moreover, transfection of recombinant constructs bearing 5’-deletions of the α4 promoter segment allows the localization of strong negative regulatory elements on the -76 to -300 region of the α4 gene suggesting that its expression is intimately linked to the proliferative state of primary cultured RPE cells.
基金supported by the National Natural Science Foundation of China(41907047)the China Scholarship Council(202106515016)the Strategic International Collaboration of Scientific and Technological Innovation for the National Key Research and Development Plan(2016YFE0202900).
文摘The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion and damage during the growth stage,which brings serious problems to the restoration of grass in the early stage.Therefore,effects of coir geotextile and geocell on EG erosion under four confluence intensities were researched in this study.Results of the simulated water discharge erosion test showed that when the confluence strength was less than 30 L/min,geocell and coir geotextile had a good effect on controlling EG erosion,and sediment yield of geocell and coir geotextile was reduced by 25.95%–37.82%and 73.73%–88.96%,respectively.However,when confluence intensity increased to 40 L/min,protective effect of coir geotextile decreased,and sediment yield rate increased sharply by 189.03%.When confluence intensity increased to 50 L/min,the protective effect of coir geotextile was lost.On the other hand,geocell showed that the greater the flow rate,the better the protective effect.In addition,with the increase in confluence intensity,erosion pattern of coir geotextile developed from sheet erosion to intermittent fall and then to completion of main rill,and the protective effect was gradually weakened.In contrast,the protective effect of EG under geocell was gradually enhanced from the continuous rill to the intermittent rill and finally to the intermittent fall.This study shows that coir geotextile and geocell can prevent EG erosion,and the effect of geocell is better than that of coir geotextile on the surface of EG.
文摘Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common.Studies of schematized confluences with a step at the interface between the tributary and the main channel bed reveal that bed elevation discordance is an important additional control for the confluence hydrodynamics.This study aimed to improve understanding of the influence of bed elevation discordance on the flow patterns and head losses in a right-angled confluence of an open channel with rectangular cross-sections.A large eddy simulation (LES)-based numerical model was set up and validated with experiments by others.Four configurations with different bed discordance ratios were investigated.The results confirm that, with increasing bed elevation discordance, the tributary streamlines at the confluence interface deviate less from the geometrical confluence angle, the extent of the recirculation zone (RZ) gets smaller, the ratio of the water depth upstream to that downstream of the confluence decreases, and the water level depression reduces.The bed elevation discordance also leads to the development of a large-scale structure in the lee of the step.Despite the appearance of the large-scale structure, the reduced extent of the RZ and associated changes in flow deflection/contraction reduce total head losses experienced by the main channel with an increase of the bed discordance ratio.It turns out that bed elevation discordance converts the lateral momentum from the tributary to streamwise momentum in the main channel more efficiently.
基金Supported by the National Excellent Youth Foundation of P,R,China(40025103)
文摘Based on two-phase flow theory and shallow water flow assumption,a mathematical model is applied to simulate debris flow.The model considers a two-phase mixture of sediments and water fluid.Assuming that the sediments and the water fluid move downstream with the same velocity,the flow of the mixture is described using a two dimensional depth averaged model with a unique 2-D momentum equation and two mass balance e- quations for the mixture and the sediments,respectively.The finite volume method is used f...
基金supported by the National Key Research and Development Program of China(Nos.2020YFB2008300 and 2020YFB2008302)the Program of Key Research and Development Program of Guangdong Province(No.2019B090921001)。
文摘Numerical simulation technology has been widely used in the foundry industry to analyze and improve casting processes.During the casting filling process,many filling-related defects form easily at the confluences of liquid metal streams.The main filling-related defects are cold shut defects.To calculate the positions of casting defects,the characteristics of liquid metal confluences were analyzed.The flow front of liquid metal was captured by the volume-of-fluid algorithm to obtain a time field,which was used to calculate the time derivatives of the liquid front position and the confluences of liquid metal streams.To distinguish small confluences from the main confluences,the concept of confluent scale was developed,which was used to filter the small confluences based on a threshold.The calculation process was demonstrated through the post-processing of numerical simulation.A "W" shaped casting and a steering wheel casting were calculated to validate the accuracy of the method developed in this study.The positions of cold shut defects were predicted by calculating the confluences of liquid metal streams.The method was proved to be practical by comparing the calculation results with the positions of cold shut defects in an end cover casting.The computation of confluences and cold shut defects can improve the analysis efficiency and provide assurance for the optimization of a casting process plan.
文摘Objective: To review our experience in and the re-sults of resecting liver tumors involving the hepatoca-val confluence under intermittent portal triad clam-ping (PTC).Methods: Sixty-eight consecutive patients with livertumors involving the hepatocaval confluence under-went hepatectomies with liver parenchymal transec-tions under intermittent PTC.Results: All the tumors were successfully resected un-der PTC, except for one in which the infrahepatic in-ferior vena cava was concomitantly occluded in addi-tion to PTC. There was neither operative death noruncontrollable massive bleeding or air embolism oc-curred in our patients. The bleedings from the mainand short hepatic veins and right adrenal veins wereproperly managed during the operation, with a meanintraoperative blood loss of 1400 ml. Of the 68tumors resected, 65 were hepatocellular carcinomas(HCC). Their 1-, 2-, 3- and 4-year suvival rateswere 64.11%, 52. 82%, 44.90% and 36.98%, re-spectively, and the patients with HCC with capsulessurvived significantly longer than those with HCCwithout capsules.Conclusions: The liver tumors involving the hepato-caval confluence could be safely resected simply un-der PTC, without routine use of total hepatic vascu-lar exclusion. As for HCCs in this area, the tumorwith capsule is a better indicator for surgical resec-tion than that without capsule.
文摘Using IAP-AGCM, a model developed by the institute of atmospheric research, Academia Sinica,controlled numerital expertrients on SST and east Asian circulation have been performed and some conclusions have been reached as follows. The abnomality of subtropical high has a two-month remote lagging response to SSTA of the western tropical Pacific, the South China Sea and the Bay of Bengal. Theabnormality always appears in pair for the western Pacific subtrphal high and the eastern Pacific subtropical high, with the latter beginning earlier than the former. When the SST of the western trophalPacific, South China Sea and Bay of Bengal anomalously decreases (increases), the subtropical high iskept anomalously more t0 the south (north),consistently so is the location at which two zonal geopotential waves meet in the subtropical western Pacific. Under the action of the SSTA above and when ablocking pattern over east Asia continent appears, the assembling location of the joinin8 waves for thewestern Pacific is closely related to that of the blocking high, which is especially important to consistentabnormality of the subtropical high.
文摘Also if rarely,hepatocellular carcinoma,cholangiocarcinoma,and metastatic carcinoma can invade the retrohepatic portion of the inferior vena cava(IVC),because of the proximity of this vessel to the liver.^([1]) Innovative vascular exclusion techniques and new surgical resection methods,derived from improvements in liver surgery and transplantation,have allowed us
文摘Here we investigate the ocean-atmosphere coupling and the contribution of the Sea Surface Temperature (SST) variations in: 1) Brazil-Malvinas Confluence (BMC) region, 2) Southwest Atlantic Ocean and 3) Southern Brazil. Numerical simulations of the ECHAM5/MPI-OM coupled ocean-atmosphere model were used to analyze the changes in the seasonal trajectory of the extratropical cyclones, in terms of intensification of physical mechanisms and implications for future scenarios. The numerical experiment for the future scenario considered an atmospheric CO2 concentration of approximately 770 ppm, which represents an increment of more than 350 ppm over the current values recorded by the Mauna Loa reference station. For this scenario, the results indicated a Storm Tracks (ST) displacement of 5° latitude toward south and changes of the meridional transport of sensible heat, close to 50°S. The increase in SST induces ST intensification and consequently an increase in the occurrence of extratropical cyclones. Overall, in the BMC region, we found a change in the pattern of cyclogenetic activity occurrence, with less frequent, but more intense events. On the Southern Brazilian region, the results of this study indicate increases in rainfall during summer months, whereas, a decrease in frequency and an increase in intensity were found for wintertime. We suggest that these changes could impact the climate dynamic of the Brazilian South coast, with a magnitude yet unknown.
文摘FOSHAN is an ancient city endowed with a bountiful culture.Located in the heartland of the vibrant Pearl River Delta,Foshan is west of Guangzhou,the capital of Guangdong Province,and gazes upon Hong Kong and Macao from the north.For centuries,Foshan has been the economic and trade center in this region,and known for its high-quality ceramic products throughout the country.In modern times,it has witnessed a growth
基金supported by the National Natural Science Foundation of China(21971227,22222113)CAS Project for Young Scientists in Basic Research(YSBR-054)+1 种基金the Fundamental Research Funds for the Central Universities(WK9990000090,WK9990000111)the Chinese Postdoctoral Science Foundation(2022TQ0324,2023M733376)。
文摘Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.
基金Indian National Science Academy for granting visiting scientist fellowship in 2019 for learning in silico studies in AyurvedaAIIA, New Delhi for laboratory support。
文摘Coalescence of traditional medicine Ayurveda and in silico technology is a rigor for supplementary development of future-ready effective traditional medicine. Ayurveda is a popular traditional medicine in South Asia, emanating worldwide for the treatment of metabolic disorders and chronic illness. Techniques of in silico biology are not much explored for the investigation of a variety of bioactive phytochemicals of Ayurvedic herbs. Drug repurposing, reverse pharmacology, and polypharmacology in Ayurveda are areas in silico explorations that are needed to understand the rich repertoire of herbs, minerals, herbo-minerals, and assorted Ayurvedic formulations. This review emphasizes exploring the concept of Ayurveda with in silico approaches and the need for Ayurinformatics studies. It also provides an overview of in silico studies done on phytoconstituents of some important Ayurvedic plants, the utility of in silico studies in Ayurvedic phytoconstituents/formulations, limitations/challenges, and prospects of in silico studies in Ayurveda. This article discusses the convergence of in silico work, especially in the least explored field of Ayurveda. The focused coalesce of these two domains could present a predictive combinatorial platform to enhance translational research magnitude. In nutshell, it could provide new insight into an Ayurvedic drug discovery involving an in silico approach that could not only alleviate the process of traditional medicine research but also enhance its effectiveness in addressing health care.
基金National Key Research and Development Program of China,No.2018YFE0184300National Natural Science Foundation of China,No.41761115,No.41271203Key Research Projects of Graduate Students in Yunnan Normal University,No.ysdyjs2019166。
文摘Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This study aims to elucidate this impact and response mechanisms using precipitation data of a climate change-sensitive confluence zone of the southwest and southeast monsoons in Yunnan Province from 1988 to 2018.The results revealed that the precipitation pattern could be divided into three periods:abundant precipitation(Stage I,from 1988 to 2004),decreased precipitation(Stage II,from 2005 to 2015),and drought recovery(Stage III,from 2016 to 2018).Following the transition from Stage I to Stage II and from Stage II to Stage III,the area of precipitation changed significantly,accounting for 15.07%,13.87%,and 16.53%of Yunnan’s total area,for Stages I,II,and III,respectively.At the provincial level,a significant positive correlation was observed between precipitation and food production(r=0.535,P<0.01),and the correlation coefficient between precipitation and grain yield was higher than that between precipitation and meat and milk production.Based on a precipitation–grain yield transect and breakpoint detection method,key precipitation thresholds affecting grain yield were estimated as 700 and 1500 mm,respectively;when precipitation was<700,700–1500,and≥1500 mm,the correlation coefficients between precipitation and grain yield were 0.448(P<0.01),0.370(P<0.01),and–0.229(P>0.05),respectively.Based on the precipitation thresholds,Yunnan Province can be divided into precipitation surplus,precipitation equilibrium,and precipitation deficit regions,corresponding countermeasures to stabilize grain yield were proposed for each of these regions.The threshold effect of precipitation on grain yield is controlled by molecular-level water–crop mechanisms,in which reactive oxygen species,a by-product of plant aerobic metabolism,plays a key regulatory role.
基金supported by the National Natural Science Foundation of China(Grant Nos.51779080,U2040205 and 52079044)supported by the Fundamental Research Funds for the Central Universities(Grant No.20195025712,B200202237)+1 种基金the 111 Project(Grant No.B17015)the Fok Ying Tung Education Foundation(Grant No.520013312)。
文摘Confluences act as critical nodes in a river system.They affect hydrodynamics,sediment transport,bed morphology,and eco-hydraulics of the river system.Convergence of streams produces the complex mechanism of flow momentum and mass mixing which may affect the aquatic environment locally and even lasting for a long distance downstream.The confluence creates a hotspot for the river system’s ecological change,which usually leads to changes in water temperature,suspended-sediment load,bed material,nutrient concentrations,water chemistry,and organic-matter content.Hence,the dynamics of river confluences are very complex and have critical effects on river system’s water environment and ecology.For this reason,a review summarizing turbulent flow,sediment transport,morphological-dynamics,mixing processes,and their effects on the ecology of the aquatic environment at river confluences is in order.A future research agenda and opportunities pertinent to river confluence are vitally emphasized as a multidisciplinary research topic.
基金supported by the National Natural Science Foundation of China(Grant No.51739011)the National Key Research and Development Program of China(Grant No.2016YFC0402707-03).
文摘For the study of the effects of partially non-submerged rigid vegetation on the free-surface confluence flow in a curved open channel,a numerical simulation is carried out by using the Volume of Fluid model combined with the porous media model with the software OpenFOAM.The model is first validated by using available experimental measurement data with a good agreement.Then,the characteristics of the separation zone generated by the centrifugal forces and the confluence flow are analyzed.Due to the resistance created by the vegetation,the velocities in the separation zone are more chaotic and the separation zone becomes smaller and more irregular.The reduction of the separation zone area of the vegetated flow in the convex bank is more significant than that in the concave bank.The velocities in the vegetated region become much smaller and remains so in the downstream flow after the vegetation region.Meanwhile,the vegetation compresses and divides the circulations in the flow area,rebuilding a structure with smaller circulations in the main flow and unclear circulations in the vegetation region.In addition,the bed wall shear stresses are significantly smaller in the vegetation region and the separation zone compared to the non-vegetated flow.This implies that the vegetation can have the effect of protecting the river bed from erosion.
