Computer simulation models are widely applied in various areas of the health care sector, including the spread of infectious diseases. Patch models involve explicit movements of people between distinct locations. The ...Computer simulation models are widely applied in various areas of the health care sector, including the spread of infectious diseases. Patch models involve explicit movements of people between distinct locations. The aim of the present work has been designed and explored a patch model with population mobility between different patches and between each patch and an external population. The authors considered a SIR （susceptible-infected-recovered） scheme. The model was explored by computer simulations. The results show how endemic levels are reached in all patches of the system. Furthermore, the performed explorations suggest that the people mobility between patches, the immigration from outside the system and the infection rate in each patch, are factors that may influence the dynamics of epidemics and should be considered in health policy planning.展开更多
A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis（tributyltin） oxide （TBTO）. The results indicate no sex-specific differences in...A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis（tributyltin） oxide （TBTO）. The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L＂1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control （P〈0.01） after 24 days exposure to concentrations higher than 10 ng TBTO L-1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase （rm）, from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration （60 ng LI）, where all females aborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased rm compared with that of control （an effect associated with decreased sex ratio）. The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.展开更多
Recently, microreactors have become available to be fabricated and used safely. The performance of these microreactors depends on the behavior of the multiphase flow hydrodynamics. Gas-liquid flow through T-junction m...Recently, microreactors have become available to be fabricated and used safely. The performance of these microreactors depends on the behavior of the multiphase flow hydrodynamics. Gas-liquid flow through T-junction microchannel reactor is simulated numerically using VOF （volume of fluid） method. 2-D （Two-dimensional） and 3-D （three-dimensional） models of the T-junction microchannel reactor were introduced to the simulations. Both 2-D and 3-D simulations for nitrogen-water flow were performed in the FLUENT （Fluent. Inc.） computational fluid dynamics package. The third direction effect has been studied by comparing the results of the 2-D and 3-D simulations with the published experimental data. Also, the bubble slug length was calculated for the 2-D and 3-D simulations. Furthermore, the hydrodynamics of the flow was studied for the 2-D and 3-D simulations, and compared with other experimental data. The pressure drop, mean bubble velocity, the velocity distribution and the void fraction were calculated and found to be in good agreement with published data.展开更多
Given Latin America＇s historical and robust religiosity, how do sociologists explain that Uruguay became an extremely secular society since the turn of the twentieth century？ Earliest attempts to interpret and expla...Given Latin America＇s historical and robust religiosity, how do sociologists explain that Uruguay became an extremely secular society since the turn of the twentieth century？ Earliest attempts to interpret and explain Uruguayan secular society came in the 1960s from Uruguayan scholars. Typically, these studies were produced by religious practitioners, or at least researchers sympathetic to religion, who attributed weak religiosity, at least weak Catholicism, to two factors： the lack of a colonial heritage and European immigration. Counterfactuals to the ＂weak institution＂ and the ＂social base＂ claims are based on new research, especially as it pertains to immigration and settlement patterns among Italian and Spanish immigrants. The counter-arguments presented here, while not entirely invalidating the ＂social base＂ and ＂weak institutional church＂ claims make it more difficult to assume that urban demographics and ecclesiastical history in Uruguay are significantly correlated to the secularization of Uruguayan society. This study is important because it creates theoretical space that should stimulate researchers to consider alternative causes for Uruguayan secular society that provide greater explanatory power by integrating historically contingent evidence in the context of theoretical explanation展开更多
The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the syste...The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the system. CFD （computational fluid dynamics） with an Eulerian-Lagrangian approach coupled with an approved erosion model is applied to visualize the 3-D flow behavior of slurry flow in both parts and to predict the erosion rate and the location of erosion at the internal surfaces. The analysis of slurry erosion is performed in five steps; geometry and grid generation, grid study/refinement, fluid flow solution, solid particles tracking and finally, the erosion calculation. In previous publications in literature considering transportation of gas-solid flows in pipe parts, the application ofT-junctions instead of elbows for specified conditions in order to reduce the erosion is recommended. In this article, it is approved that for liquid-solid flows, the Stokes number is reasonably smaller than the values for gas-solid flows. This causes the solid particles tightly couple to the fluid phase and to travel more closely with the fluid streamlines. The effects of important influencing parameters such as feed flow velocity, solid concentration, particle size and shape are investigated in detail in current work. It was found that for liquid-solid flows, the erosion of T-junction for all of the mentioned influencing parameters, due to its geometrical specifications and Stokes number variation in comparison with gas-solid flows, is reasonably higher than erosion of elbow. Due to these findings, in contrary to the gas-solid mixture flows, application of T-junction instead of elbow for liquid-solid flow transportation is not recommended.展开更多
The article studies trade in goods between China and the Latin American and Caribbean （LAC） countries and between the European Union （EU） and LAC during the years from 2000 to 2013. From the beginning of the 21st ...The article studies trade in goods between China and the Latin American and Caribbean （LAC） countries and between the European Union （EU） and LAC during the years from 2000 to 2013. From the beginning of the 21st century, big changes in LAC＇s trade patterns have been observed. The article contains possible explanation of them. The analysis is based on the ECLAC （Economic Commission for Latin America and the Caribbean） data. Merchandise trade between China and LAC grew significantly over the period from 2000 to 2013. In 2013, the value of merchandise exports from China was higher than from the EU-28 in the case of 12 LAC countries. Chinese imports of goods surpassed the European ones in five countries in the region. In order to increase its exports of manufactured goods and imports of natural resources and agricultural commodities, China combines trade arrangements with foreign aid policy. Besides, a rapid development of bilateral diplomatic ties between China and LAC is observed. The EU-LAC trade relations have worsened during the last decade mainly due to financial crisis and development of the EU-Asia trade relations.展开更多
1-butyl-3-methylimidazolium perchlorate([BMIM]ClO4) was synthesized by two steps with N-methylimidazolium.Some physico-chemical properties,such as density,surface tension,viscosity,electrical conductivity as well as e...1-butyl-3-methylimidazolium perchlorate([BMIM]ClO4) was synthesized by two steps with N-methylimidazolium.Some physico-chemical properties,such as density,surface tension,viscosity,electrical conductivity as well as electrochemical window,were investigated and solvent performance was also studied.The results show that this kind of ionic liquid is an excellent electrolyte with low viscosity,high electrical conductivity and wide electrochemical window.In addition,[BMIM]ClO4 is soluble in most conventional solvents and some metal oxides have high solubility in it,which lays the foundation of direct electrolysis of metal oxides in this ionic liquid.展开更多
Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis （UC）. However, it is not established whether systemically administered butyrate benefits such patients. The current study a...Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis （UC）. However, it is not established whether systemically administered butyrate benefits such patients. The current study aimed at ex- ploring and comparing the potential of intraperitoneally, intrarectally, and orally administered butyrate against acetic acid （AA）-induced UC in rats. Intrarectal administration of 2 ml of 50% AA was done after or without prior treatment of rats for 7 consecutive days with 100 mg/kg sodium butyrate （SB） intraperitoneally, intrarectally, or orally. Rats were sacrificed after 48 h of hA-treatment. Subsequently, colon sections were processed routinely for histopathological examination. We clinically observed diarrhea, loose stools, and hemoccult-positive stools, and histologically, epithelial loss and ulceration, crypt damage, goblet cell depletion, hemorrhage, and mucosal infiltration of inflammatory cells. The changes were significantly reduced by intraperitoneal, intrarectal, or oral butyrate, with intraperitoneal butyrate exhibiting the highest potency. It is concluded that intraperitoneal administration of butyrate abrogates the lesions of hA-induced UC and its potency surpasses that of intrarectal or oral butyrate.展开更多
We conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface. The evolution of bubble mor- ph...We conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface. The evolution of bubble mor- phology and the distributions of velocity and pressure in flow field are analyzed, and the effect of width ratio between main channel and branch on the bubble mor- phology are evaluated. The results indicate that, the ＂tun- nel＂ breakup, obstructed breakup, combined breakup and non-breakup are observed during the bubble flows through the T-junctions under different condition. The whole bub- ble breakup process undergoes the extension, squeeze and pinch-off stages, while the non-breakup process experi- ences extension and pushing stages. We find that, in the squeeze stage, a local vortex flow forms at the front edge of the bubble for the ＂tunnel＂ breakup while the velocity inside the bubble is of a parabolic distribution for the obstructed breakup. Irrespective of non-breakup regimes, there is a sudden pressure drop occurring at the gas-liquid interface of the bubble in the squeeze stage, and the pres- sure drop at the front interface is far larger than that at the depression region. The transition of the bubble breakup regime through the T-junction occurs with an increase in width ratio of main channel to the branch, which sequen- tially experiences the non-breakup regime, ＂tunnel＂ breakup regime and obstructed breakup regime. The flow regime diagrams are plotted with a power-law correlation to distinguish the bubble/droplet breakup and non-breakup regimes, which also characterize the difference between bubble and droplet breakup through a T-junction.展开更多
The aim of this study was to prepare pulsatile release tablets which provide different drug delayed-release time and realize personalized administration according to the needs of patients.Fused deposition modeling(FDM...The aim of this study was to prepare pulsatile release tablets which provide different drug delayed-release time and realize personalized administration according to the needs of patients.Fused deposition modeling(FDM)3D printing technology was introduced into the field of pharmaceutics in this study,and the feasibility to prepare core-shell pulsatile release tablets was explored by combing 3D printing technology with the traditional manufacturing technology.The core of the pulsatile tablets was a commercial tablet obtained from the traditional technology,and the drug-free shell was prepared by the FDM 3D printing technology.Three kinds of tablet shells were designed using different parameters.Furthermore,the morphology,size,weight,hardness,and in vitro drug release of the 3D printed famotidine pusatile tablets were characterized and evaluated.The results showed that the 3D printed tablets appeared intact without any defects.Different parameters of outer shell affected the size,weight,hardness,and in vitro drug release of the tablets.The tablets achieved a personalized delayed release time varying from 5 to 7 h in vitro.In this way,a new method for preparing pulsatile release tablets and a new way for the personalized administration of pulsatile tablets were explored in this study.展开更多
文摘Computer simulation models are widely applied in various areas of the health care sector, including the spread of infectious diseases. Patch models involve explicit movements of people between distinct locations. The aim of the present work has been designed and explored a patch model with population mobility between different patches and between each patch and an external population. The authors considered a SIR （susceptible-infected-recovered） scheme. The model was explored by computer simulations. The results show how endemic levels are reached in all patches of the system. Furthermore, the performed explorations suggest that the people mobility between patches, the immigration from outside the system and the infection rate in each patch, are factors that may influence the dynamics of epidemics and should be considered in health policy planning.
基金Supported by the National Basic Research Program of China(973 Program)(No.2005CB422300)
文摘A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis（tributyltin） oxide （TBTO）. The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L＂1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control （P〈0.01） after 24 days exposure to concentrations higher than 10 ng TBTO L-1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase （rm）, from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration （60 ng LI）, where all females aborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased rm compared with that of control （an effect associated with decreased sex ratio）. The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.
文摘Recently, microreactors have become available to be fabricated and used safely. The performance of these microreactors depends on the behavior of the multiphase flow hydrodynamics. Gas-liquid flow through T-junction microchannel reactor is simulated numerically using VOF （volume of fluid） method. 2-D （Two-dimensional） and 3-D （three-dimensional） models of the T-junction microchannel reactor were introduced to the simulations. Both 2-D and 3-D simulations for nitrogen-water flow were performed in the FLUENT （Fluent. Inc.） computational fluid dynamics package. The third direction effect has been studied by comparing the results of the 2-D and 3-D simulations with the published experimental data. Also, the bubble slug length was calculated for the 2-D and 3-D simulations. Furthermore, the hydrodynamics of the flow was studied for the 2-D and 3-D simulations, and compared with other experimental data. The pressure drop, mean bubble velocity, the velocity distribution and the void fraction were calculated and found to be in good agreement with published data.
文摘Given Latin America＇s historical and robust religiosity, how do sociologists explain that Uruguay became an extremely secular society since the turn of the twentieth century？ Earliest attempts to interpret and explain Uruguayan secular society came in the 1960s from Uruguayan scholars. Typically, these studies were produced by religious practitioners, or at least researchers sympathetic to religion, who attributed weak religiosity, at least weak Catholicism, to two factors： the lack of a colonial heritage and European immigration. Counterfactuals to the ＂weak institution＂ and the ＂social base＂ claims are based on new research, especially as it pertains to immigration and settlement patterns among Italian and Spanish immigrants. The counter-arguments presented here, while not entirely invalidating the ＂social base＂ and ＂weak institutional church＂ claims make it more difficult to assume that urban demographics and ecclesiastical history in Uruguay are significantly correlated to the secularization of Uruguayan society. This study is important because it creates theoretical space that should stimulate researchers to consider alternative causes for Uruguayan secular society that provide greater explanatory power by integrating historically contingent evidence in the context of theoretical explanation
文摘The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the system. CFD （computational fluid dynamics） with an Eulerian-Lagrangian approach coupled with an approved erosion model is applied to visualize the 3-D flow behavior of slurry flow in both parts and to predict the erosion rate and the location of erosion at the internal surfaces. The analysis of slurry erosion is performed in five steps; geometry and grid generation, grid study/refinement, fluid flow solution, solid particles tracking and finally, the erosion calculation. In previous publications in literature considering transportation of gas-solid flows in pipe parts, the application ofT-junctions instead of elbows for specified conditions in order to reduce the erosion is recommended. In this article, it is approved that for liquid-solid flows, the Stokes number is reasonably smaller than the values for gas-solid flows. This causes the solid particles tightly couple to the fluid phase and to travel more closely with the fluid streamlines. The effects of important influencing parameters such as feed flow velocity, solid concentration, particle size and shape are investigated in detail in current work. It was found that for liquid-solid flows, the erosion of T-junction for all of the mentioned influencing parameters, due to its geometrical specifications and Stokes number variation in comparison with gas-solid flows, is reasonably higher than erosion of elbow. Due to these findings, in contrary to the gas-solid mixture flows, application of T-junction instead of elbow for liquid-solid flow transportation is not recommended.
文摘The article studies trade in goods between China and the Latin American and Caribbean （LAC） countries and between the European Union （EU） and LAC during the years from 2000 to 2013. From the beginning of the 21st century, big changes in LAC＇s trade patterns have been observed. The article contains possible explanation of them. The analysis is based on the ECLAC （Economic Commission for Latin America and the Caribbean） data. Merchandise trade between China and LAC grew significantly over the period from 2000 to 2013. In 2013, the value of merchandise exports from China was higher than from the EU-28 in the case of 12 LAC countries. Chinese imports of goods surpassed the European ones in five countries in the region. In order to increase its exports of manufactured goods and imports of natural resources and agricultural commodities, China combines trade arrangements with foreign aid policy. Besides, a rapid development of bilateral diplomatic ties between China and LAC is observed. The EU-LAC trade relations have worsened during the last decade mainly due to financial crisis and development of the EU-Asia trade relations.
基金Project(50574031) supported by the National Natural Science Foundation of China
文摘1-butyl-3-methylimidazolium perchlorate([BMIM]ClO4) was synthesized by two steps with N-methylimidazolium.Some physico-chemical properties,such as density,surface tension,viscosity,electrical conductivity as well as electrochemical window,were investigated and solvent performance was also studied.The results show that this kind of ionic liquid is an excellent electrolyte with low viscosity,high electrical conductivity and wide electrochemical window.In addition,[BMIM]ClO4 is soluble in most conventional solvents and some metal oxides have high solubility in it,which lays the foundation of direct electrolysis of metal oxides in this ionic liquid.
文摘Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis （UC）. However, it is not established whether systemically administered butyrate benefits such patients. The current study aimed at ex- ploring and comparing the potential of intraperitoneally, intrarectally, and orally administered butyrate against acetic acid （AA）-induced UC in rats. Intrarectal administration of 2 ml of 50% AA was done after or without prior treatment of rats for 7 consecutive days with 100 mg/kg sodium butyrate （SB） intraperitoneally, intrarectally, or orally. Rats were sacrificed after 48 h of hA-treatment. Subsequently, colon sections were processed routinely for histopathological examination. We clinically observed diarrhea, loose stools, and hemoccult-positive stools, and histologically, epithelial loss and ulceration, crypt damage, goblet cell depletion, hemorrhage, and mucosal infiltration of inflammatory cells. The changes were significantly reduced by intraperitoneal, intrarectal, or oral butyrate, with intraperitoneal butyrate exhibiting the highest potency. It is concluded that intraperitoneal administration of butyrate abrogates the lesions of hA-induced UC and its potency surpasses that of intrarectal or oral butyrate.
文摘We conduct a computational fluid dynamics simulation to investigate the behaviors of bubble breakup in a microfluidic T-junction using volume-of-fluid method to represent the interface. The evolution of bubble mor- phology and the distributions of velocity and pressure in flow field are analyzed, and the effect of width ratio between main channel and branch on the bubble mor- phology are evaluated. The results indicate that, the ＂tun- nel＂ breakup, obstructed breakup, combined breakup and non-breakup are observed during the bubble flows through the T-junctions under different condition. The whole bub- ble breakup process undergoes the extension, squeeze and pinch-off stages, while the non-breakup process experi- ences extension and pushing stages. We find that, in the squeeze stage, a local vortex flow forms at the front edge of the bubble for the ＂tunnel＂ breakup while the velocity inside the bubble is of a parabolic distribution for the obstructed breakup. Irrespective of non-breakup regimes, there is a sudden pressure drop occurring at the gas-liquid interface of the bubble in the squeeze stage, and the pres- sure drop at the front interface is far larger than that at the depression region. The transition of the bubble breakup regime through the T-junction occurs with an increase in width ratio of main channel to the branch, which sequen- tially experiences the non-breakup regime, ＂tunnel＂ breakup regime and obstructed breakup regime. The flow regime diagrams are plotted with a power-law correlation to distinguish the bubble/droplet breakup and non-breakup regimes, which also characterize the difference between bubble and droplet breakup through a T-junction.
文摘The aim of this study was to prepare pulsatile release tablets which provide different drug delayed-release time and realize personalized administration according to the needs of patients.Fused deposition modeling(FDM)3D printing technology was introduced into the field of pharmaceutics in this study,and the feasibility to prepare core-shell pulsatile release tablets was explored by combing 3D printing technology with the traditional manufacturing technology.The core of the pulsatile tablets was a commercial tablet obtained from the traditional technology,and the drug-free shell was prepared by the FDM 3D printing technology.Three kinds of tablet shells were designed using different parameters.Furthermore,the morphology,size,weight,hardness,and in vitro drug release of the 3D printed famotidine pusatile tablets were characterized and evaluated.The results showed that the 3D printed tablets appeared intact without any defects.Different parameters of outer shell affected the size,weight,hardness,and in vitro drug release of the tablets.The tablets achieved a personalized delayed release time varying from 5 to 7 h in vitro.In this way,a new method for preparing pulsatile release tablets and a new way for the personalized administration of pulsatile tablets were explored in this study.
