In this paper we construct an extended non-competitive input-occupancy-output model that captures China＇s processing trade and also develop a methodology to estimate the domestic value-added and employment generated ...In this paper we construct an extended non-competitive input-occupancy-output model that captures China＇s processing trade and also develop a methodology to estimate the domestic value-added and employment generated by each unit of total exports, of exports by sector, and of exports by commodity, respectively. We also prove mathematically that the gross value of exports is equal to the sum of total value added and total imports. Based on the methodology proposed here, we compile the 2002 extended Chinese non-competitive input-occupancy-output table and the United States non-competitive input-occupancy- output table, and then estimate and analyze the effects of China＇s exports and US exports on their respective domestic value added and employment.展开更多
Internet use has become an indispensable part of people’s daily lives,and the relationship between Internet use and residents’subjective well-being is receiving increasing attention from researchers.However,the exis...Internet use has become an indispensable part of people’s daily lives,and the relationship between Internet use and residents’subjective well-being is receiving increasing attention from researchers.However,the existing literature on the relationship between Internet use and residents’subjective well-being is still controversial and inconclusive,and there has been relatively little discussion of the mechanisms by which Internet use affects well-being.On the basis of data from the China General Social Survey 2015(CGSS2015),this paper provides an empirical analysis of the impact of Internet usage on residents’subjective wellbeing.The study finds that while Internet use had no significant impact on the well-being of residents compared to non-use,frequency of Internet usage did significantly improve subjective well-being.On this basis,we tested the mechanisms by which Internet use affects residents’well-being through the three channels of the personal income effect,the human capital effect and the social capital effect.The findings partially verify the hypothesis of the mediating effect of social capital between Internet use and residents’subjective wellbeing,but do not verify the hypothesis of the moderating effect of personal income and human capital.Compared with previous studies,this paper is innovative in the following three ways:it uses the latest available representative national microdata,which is better able to reflect recent Internet usage and its impact on residents’subjective well-being;on the basis of existing research on the impact of Internet usage on residents’well-being,it analyzes the specific mechanisms through which Internet use affects well-being,using the moderating effect model and the mediating effect model to make up for the shortcomings of existing research on the impact mechanism;and it applies the Bioprobit model to deal with the potential endogeneity of key explanatory variables,using a variety of model estimation methods to obtain more robust estimation results.展开更多
Altered micro RNA（mi RNA） associated with gastric cancer（GC） development and mi R-17 and mi R-106 b were differentially expressed in GC tissues. This study detected serum levels of mi R-17 and mi R-106 b expressio...Altered micro RNA（mi RNA） associated with gastric cancer（GC） development and mi R-17 and mi R-106 b were differentially expressed in GC tissues. This study detected serum levels of mi R-17 and mi R-106 b expression in GC, benign gastric disease（BGD） and healthy controls to assess them as tumor markers for GC. Serum samples from 40 GC, 32 BGD（10 gastric ulcer, 14 gastric polyps, and 8 gastric ulcer with polyps） and 36 healthy individuals were subjected to quantitative reverse transcription polymerase chain reaction（q RT-PCR） analysis of mi R-17 and mi R-106 b expression. The data showed that the serum levels of mi R-17 and mi R-106 b were significantly reduced in healthy individuals and BGD patients compared to GC patients. There was a significant association of mi R-17 and mi R-106 b expression with age, but not with other clinicopathological features, such as gender, tumor differentiation, stage and lymphatic metastasis. Further analysis showed that, in discriminating GC patients from healthy controls, mi R-17 could yield a receiver-operating characteristic（ROC） area under the curve（AUC） of 0.879 with 80.6% sensitivity and 87.5% specificity and mi R-106 b could yield an AUC of 0.856 with 75.0% sensitivity and 92.5% specificity. The combined AUC of mi R-17 and mi R-106 b was 0.913 with 83.3% sensitivity and 87.5% specificity. Collectively, these data suggest that detection of serum mi R-17 and mi R-106 b levels should be further evaluated as novel non-invasive biomarkers in early GC detection and surveillance of disease progression.展开更多
Since 2001, the exports of foreign-invested enterprises （FIEs） have accounted for more than 50percent of China＇s total exports. As foreign capital occupies a high proportion of the total capital of FIEs, most FIEs ...Since 2001, the exports of foreign-invested enterprises （FIEs） have accounted for more than 50percent of China＇s total exports. As foreign capital occupies a high proportion of the total capital of FIEs, most FIEs ＇ capital gains are foreign factor income. Although these gains are calculated as apart of China＇s GDP, they do not belong to China＇s national income. To determine the real contribution of exports to China ＂s welfare, the present paper analyses the impact of exports on China ＂s national income using a non-competitive input output model capturing processing trade. The results show that every US$1000 of China＇s exports generates US$506.8 of national income. The real contribution of exports to China ＂s welfare is much smaller than what we expected. This suggests that China should endeavor to improve the gains from international markets orfind another engine to maintain its economic growth.展开更多
Based on the techniques of sequential extraction and X-ray powder diffraction(XRD) ,the distribution characteristics of phosphorus speciation were investigated in 13 sediment samples from Lake Hongfeng,an important dr...Based on the techniques of sequential extraction and X-ray powder diffraction(XRD) ,the distribution characteristics of phosphorus speciation were investigated in 13 sediment samples from Lake Hongfeng,an important drinking water source for Guiyang with a typical karstic limestone environment.The total phosphorus(TP) concentrations in the sediments ranged from 973.36 to 2334.18 mg/kg with a mean concentration of 1635.87 mg/kg(dry weight) ,and it was evident that the phosphorus level in the sediments was high compared with other eutrophic lakes such as Lake Chaohu and Lake Xihu.The results of the two methods,sequential extraction and XRD,demonstrated the presence of different phosphorus species in the lake sediments.Being compatible with local geophysical characteristics,the results of sequential extraction techniques indicate that the average percentages of dissolved phosphorus(DP) ,aluminum-bound phosphorus(Al-P) ,iron-bound phosphorus(Fe-P) ,calcium-bound phosphorus(Ca-P) and organic phosphorus(OP) in the sediments were 0.40%,7.06%,5.07%,45.48%and 38.49%,respectively.Notably,the concentrations of inorganic phosphorus(IP) were higher than those of OP,and the IP consisted primarily of Ca-P.The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable,inert and non-bioavailable phosphorus fraction.The results of XRD analysis indicated that,among phosphorus species,AlPO4 was found in all sediment samples at relatively high concentrations.Moreover,the TP concentrations in the sediments were high;thus the release potential and bioavailability of phosphorus in the sediments was important.Further statistical analyses of the results revealed significant correlations between phosphorus species in the sediments with two extractable principal components and four selectable cluster levels allowing interpretation of possible origins of phosphorus loading and transformation mechanisms of phosphorus species.Furthermore,available remediation measures were 展开更多
OBJECTIVE: To observe the effect of stimulating Qihai(CV 6) and bilateral Tianshu(ST 25) with herb-partitioned moxibustion(HPM) in rats with Crohn's disease(CD), and to investigate the possible anti-inflammatory m...OBJECTIVE: To observe the effect of stimulating Qihai(CV 6) and bilateral Tianshu(ST 25) with herb-partitioned moxibustion(HPM) in rats with Crohn's disease(CD), and to investigate the possible anti-inflammatory mechanism of HPM.METHODS: Forty rats were randomly divided into four groups(n = 10 rats per group): normal control(NC), model control(MC), mesalamine(MES), and HPM. The CD rat model was established in the MC,MES, and HPM groups by administering a mixture of trinitrobenzenesulfonic acid and alcohol via enema. The HPM group received HPM on Qihai(CV 6)and bilateral Tianshu(ST 25), while the MES group received intragastric mesalamine. Colonic histomorphological scores, and serum concentrations of tumor necrosis factor α(TNF-α) and interleukin 1β(IL-1β) were assessed to evaluate the effects of HPM on colonic reparation and anti-inflammation.The expressions of Toll-like receptor 4(TLR-4), nuclear factor κB inhibitor α(IκB-α), IκB kinase α/β(IKKα/β), and NF-κB p65 were further analyzed to investigate the regulatory effects of the interventions on the TLR4/NF-κB pathway.RESULTS: CD rats showed inflammatory colonic damage and increased serum concentrations of TNF-α and IL-1β. The expressions of TLR4, IKKα/β,and NF-κB p65 in the colons of CD rats were significantly increased compared with the NC group,while the expression of IκBα(a key negative regulator of NF-κB p65) was decreased. HPM significantly mitigated colonic damage and reduced the serum concentrations of TNF-α and IL-1β. HPM downregulated the expressions of TLR4, IKKα/β, and NF-κB p65 in the colon, and upregulated the expression of IκBα. The effects of HPM in CD rats were similar to those of mesalamine.CONCLUSION: HPM alleviates colonic inflammation in CD rats. This may be achieved through regulation of TLR4, which induces NF-κB signal transduction.展开更多
Clinical guidelines recommend a steady-state vancomycin(VCM)trough concentration(SVTC)of 10–15 mg/L for regular infections and 15–20 mg/L for severe infections.However,clinical trials have shown that increasing SVTC...Clinical guidelines recommend a steady-state vancomycin(VCM)trough concentration(SVTC)of 10–15 mg/L for regular infections and 15–20 mg/L for severe infections.However,clinical trials have shown that increasing SVTC is not beneficial for efficacy,and instead it leads to nephrotoxicity.To verify whether increasing the SVTC results in improved clinical outcomes with sustainable adverse effects,we prospectively determined its correlation with clinical efficacy and safety.The participants included patients hospitalized with Gram-positive bacterial infections from March 2017 through October 2018.The patients were classified into group I(SVTC<10 mg/L),II(10≤SVTC≤20 mg/L),or III(SVTC>20 mg/L).Clinical,microbiological,and laboratory data were collected.Clinical outcomes between group I and II were matched after propensity score matching(PSM).A total of 331 patients were included in this study.Clinical failure occurred in 59(29%)of 204 patients on day 14,with no significant difference between groups I and II(P=0.535).Infection recurred at 28 d in 62(30%)of 204 patients,and no significant difference in infection recurrence was observed between both the groups(log-rank,P=0.674).Except for a significant increase in the incidence of acute kidney injury in group II,no significant difference was observed between two groups for any clinical results.The incidence of adverse events in groups I and II was significantly lower than that in group III(P<0.001).SVTC had an applicable cut-off point at 14.55 mg/L.SVTC was not correlated with VCM clinical efficacy,while it was a good indicator of nephrotoxicity.展开更多
The nanomechanical resonator based on a levitated particle exhibits unique advantages in the development of ultrasensitive electric field detectors. We demonstrate a three-dimensional, high-sensitivity electric field ...The nanomechanical resonator based on a levitated particle exhibits unique advantages in the development of ultrasensitive electric field detectors. We demonstrate a three-dimensional, high-sensitivity electric field measurement technology using the optically levitated nanoparticle with known net charge. By scanning the relative position between nanoparticle and parallel electrodes, the three-dimensional electric field distribution with microscale resolution is obtained. The measured noise equivalent electric intensity with charges of 100e reaches the order of 1 μV·cm^(-1)·Hz^(-1/2)at 1.4 × 10^(-7) mbar. Linearity analysis near resonance frequency shows a measured linear range over 91 d B limited only by the maximum output voltage of the driving equipment. This work may provide an avenue for developing a high-sensitivity electric field sensor based on an optically levitated nano-resonator.展开更多
CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(I...CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source categories.Here,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local statistics.Global CO_(2)emissions from fossil fuel combustion and cement production in 1970–2021 were then estimated with highly-resolved source category(1,484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021 were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission accounting.With the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate mitigation.Remarkable differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different regions.Our estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small emitters.Our database,named the Multiresolution Emission Inventory model for Climate and air pollution research(MEIC)is publicly available through http://meicmodel.org.cn with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate research.展开更多
OBJECTIVE: To assess the effectiveness of acupuncture for the treatment of functional constipation(FC).METHODS: The literature was searched for randomized controlled trials(RCTs) comparing acupuncture with medical tre...OBJECTIVE: To assess the effectiveness of acupuncture for the treatment of functional constipation(FC).METHODS: The literature was searched for randomized controlled trials(RCTs) comparing acupuncture with medical treatment; no medical treatment,placebo acupuncture, and sham acupuncture in patients with FC were searched. Data were extracted by two independent reviewers using standard data extraction forms. Risk of bias for each RCT was assessed using a modified Oxford 5-point quality scale. Data were pooled according to intervention and treatment course. Parameters evaluated included effectiveness/invalidity, Cleveland Clinic score(CCS), colon transit time(CTT) and adverse effects.RESULTS: Nineteen studies involving 1679 participants were eligible for inclusion; of these studies,16 were published in Chinese and three in English.Risks of bias were high. Acupuncture was significantly superior to medication therapy in short-term(effectiveness/invalidity, P = 0.0009; CCS, P = 0.02)and long-term(effectiveness/invalidity, P = 0.004;CCS, P = 0.04; CCT, P < 0.0001) effectiveness. A short treatment course of less than 15 days was sufficient. The likelihood of adverse effects was significantly lower for acupuncture than for medication therapy(P = 0.002).CONCLUSION: Compared with medication, acupuncture was more effective and had a lower adverse effect rate in the treatment of FC. A short treatment course of two weeks was sufficient for a good effect. However, the poor quality of the included trials indicates the need for well-designed RCTs, including adequate sample size and a reasonable placebo control, to assess the effectiveness of acupuncture for FC.展开更多
Background:Cancer has become a global health problem,and assessments of cancer mortality are important for effective public health policy-making and adequate resource allocation.In this study,we aimed to predict the m...Background:Cancer has become a global health problem,and assessments of cancer mortality are important for effective public health policy-making and adequate resource allocation.In this study,we aimed to predict the mortality rates and numbers of deaths related to four common cancers(lung,liver,stomach,and esophagus)in China from 2020 to 2030 and to estimate the corresponding cancer burden caused by population aging and tobacco smoking.Methods:Cancer mortality data(2004-2017)were extracted from China’s death surveillance datasets,and China’s population figures(2020-2030)were obtained from the United Nations population projections.Smoking prevalence data were retrieved from a World Health Organization global report,and relative risks of smoking and cancers were derived from large-scale Asian studies.We predicted the deaths related to the four major cancers and age-standardized mortality rates using joinpoint regression and linear regression models.The tobacco smoking related burden of these four major cancers was estimated using the population attributable fraction.Results:Unlike lung cancer mortality which was predicted to continue to increase,the age-standardized mortality rates for digestive cancers(liver,stomach,and esophageal cancers)are predicted to decline over the next decade.The number of deaths caused by the four major cancers is predicted to increase from 1,490,304 in 2020 to 1,823,960 in 2030.The age-specific mortality rates of the four major cancers are predicted to increase with age after 40-45 years,peaking in the age groups of 80-84 and ≥85 years.In 2030,the combined number of deaths from the four examined cancers among adults aged ≥65 years is predicted to be 1,167,153,accounting for 64% of all deaths from these cancers.Tobacco smoking is predicted to contribute to nearly 29% of deaths fromthese cancers,corresponding to 527,577 deaths.Conclusions:The overall trend in the combined total mortality from four major cancers is predicted to decline over the next decade;however,the corresponding 展开更多
There has been considerable debate about the major factors responsible for the dramatic decline of China＇s energy intensity in the 1980s and 1990s. However, few detailed analysis has been done to explain the fluctuat...There has been considerable debate about the major factors responsible for the dramatic decline of China＇s energy intensity in the 1980s and 1990s. However, few detailed analysis has been done to explain the fluctuation in energy intensity during 2002-005. In this paper, we use the structural decomposition analysis （SDA） to decompose energy intensity into five determining factors： Energy input coefficient, technology coefficient （Leontief inverse coefficient）, final demands structure by product, final demands by category and final energy consumption coefficient. We then further decompose two coefficients, energy input coefficient and technology coefficient, into structure and real coefficient. Empirical study is carried out based on the energy-input-output tables from 1987 to 2005 in 2000 constant price. The results show that between 1987 and 2002, energy input structure accounts for most of the decline in energy intensity. However, the input structure and final demands structure by product explain the increase of the energy intensity between 2002 and 2005.展开更多
Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use o...Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use of structures.The main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage assessment.However,for many shear-type structures,it is difficult to obtain accurate FEM.In order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this paper.This method only needs to measure a few low-order vibration modes of the structure.The proposed defect diagnosis method is divided into two stages.In the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after damage.In the second stage,damage severity is evaluated based on an improved frequency sensitivity equation.Themain innovations of this method lie in two aspects.The first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear structure.The second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite elementmodel.Thismethod has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear structure.Based on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element modeling.The proposed method should be a very simple and practical defect diagnosis technique in engineering practice.展开更多
This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization...This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization,including building bridges,accelerating the transformation of achievements,promoting the value-added of the whole agricultural industry chain,and promoting the rapid development of rural industrial economy.It also discusses the working achievements of science and technology commissioners,in order to promote further development of rural revitalization in Guangdong Province.展开更多
基金This is a translated version of the paper published in Chinese in Social Sciences in China （Zhongguo shehui kexue, 2007, no. 5, pp. 91-103）, which has received the ＂Pei-Kang CHANG Development Economics Award＂ and ＂Sun Yefang Economics Award.＂ The authors are grateful to Mr. Tung Chee- hwa, former President of Hong Kong SAR, Chinese University of Hong Kong and National Natural Science Foundation of China （No. 70810107020, 70871108, 60474063） for their financial support. The authors thank Dr Wang Zhi from US International Trade Commission, and anonymous referees for their useful comments. Usual claims are applied.
文摘In this paper we construct an extended non-competitive input-occupancy-output model that captures China＇s processing trade and also develop a methodology to estimate the domestic value-added and employment generated by each unit of total exports, of exports by sector, and of exports by commodity, respectively. We also prove mathematically that the gross value of exports is equal to the sum of total value added and total imports. Based on the methodology proposed here, we compile the 2002 extended Chinese non-competitive input-occupancy-output table and the United States non-competitive input-occupancy- output table, and then estimate and analyze the effects of China＇s exports and US exports on their respective domestic value added and employment.
文摘Internet use has become an indispensable part of people’s daily lives,and the relationship between Internet use and residents’subjective well-being is receiving increasing attention from researchers.However,the existing literature on the relationship between Internet use and residents’subjective well-being is still controversial and inconclusive,and there has been relatively little discussion of the mechanisms by which Internet use affects well-being.On the basis of data from the China General Social Survey 2015(CGSS2015),this paper provides an empirical analysis of the impact of Internet usage on residents’subjective wellbeing.The study finds that while Internet use had no significant impact on the well-being of residents compared to non-use,frequency of Internet usage did significantly improve subjective well-being.On this basis,we tested the mechanisms by which Internet use affects residents’well-being through the three channels of the personal income effect,the human capital effect and the social capital effect.The findings partially verify the hypothesis of the mediating effect of social capital between Internet use and residents’subjective wellbeing,but do not verify the hypothesis of the moderating effect of personal income and human capital.Compared with previous studies,this paper is innovative in the following three ways:it uses the latest available representative national microdata,which is better able to reflect recent Internet usage and its impact on residents’subjective well-being;on the basis of existing research on the impact of Internet usage on residents’well-being,it analyzes the specific mechanisms through which Internet use affects well-being,using the moderating effect model and the mediating effect model to make up for the shortcomings of existing research on the impact mechanism;and it applies the Bioprobit model to deal with the potential endogeneity of key explanatory variables,using a variety of model estimation methods to obtain more robust estimation results.
基金supported by National Natural Science Foundation of China (Grant No. 81372140, 81301688, 81272192, 81171882, 81172298)Ph.D. Programs Foundation of Ministry of Education of China (No. 20130162110050 and 20130162120093)+6 种基金Post-doctoral Foundation of Central South University (No. 131425) China Postdoctoral Science Foundation (2014M552167)Key Program for International Cooperation Projects of Hunan Province (no. 2011WK2011)Natural Science Foundation of Hunan Province (Grant No. 12JJ4088)Technology Project of Hunan Province (2012SK3229)Research foundation of Health Department of Hunan Province (B2012-100)125 Talent Project of the Third Xiangya Hospital of Central South University
文摘Altered micro RNA（mi RNA） associated with gastric cancer（GC） development and mi R-17 and mi R-106 b were differentially expressed in GC tissues. This study detected serum levels of mi R-17 and mi R-106 b expression in GC, benign gastric disease（BGD） and healthy controls to assess them as tumor markers for GC. Serum samples from 40 GC, 32 BGD（10 gastric ulcer, 14 gastric polyps, and 8 gastric ulcer with polyps） and 36 healthy individuals were subjected to quantitative reverse transcription polymerase chain reaction（q RT-PCR） analysis of mi R-17 and mi R-106 b expression. The data showed that the serum levels of mi R-17 and mi R-106 b were significantly reduced in healthy individuals and BGD patients compared to GC patients. There was a significant association of mi R-17 and mi R-106 b expression with age, but not with other clinicopathological features, such as gender, tumor differentiation, stage and lymphatic metastasis. Further analysis showed that, in discriminating GC patients from healthy controls, mi R-17 could yield a receiver-operating characteristic（ROC） area under the curve（AUC） of 0.879 with 80.6% sensitivity and 87.5% specificity and mi R-106 b could yield an AUC of 0.856 with 75.0% sensitivity and 92.5% specificity. The combined AUC of mi R-17 and mi R-106 b was 0.913 with 83.3% sensitivity and 87.5% specificity. Collectively, these data suggest that detection of serum mi R-17 and mi R-106 b levels should be further evaluated as novel non-invasive biomarkers in early GC detection and surveillance of disease progression.
基金supported by the National Natural Science Foundation of China(Grant Nos.71003093, 70871108 and 70810107020)
文摘Since 2001, the exports of foreign-invested enterprises （FIEs） have accounted for more than 50percent of China＇s total exports. As foreign capital occupies a high proportion of the total capital of FIEs, most FIEs ＇ capital gains are foreign factor income. Although these gains are calculated as apart of China＇s GDP, they do not belong to China＇s national income. To determine the real contribution of exports to China ＂s welfare, the present paper analyses the impact of exports on China ＂s national income using a non-competitive input output model capturing processing trade. The results show that every US$1000 of China＇s exports generates US$506.8 of national income. The real contribution of exports to China ＂s welfare is much smaller than what we expected. This suggests that China should endeavor to improve the gains from international markets orfind another engine to maintain its economic growth.
基金supported by the National Natural Science Foundation of China(20967003)
文摘Based on the techniques of sequential extraction and X-ray powder diffraction(XRD) ,the distribution characteristics of phosphorus speciation were investigated in 13 sediment samples from Lake Hongfeng,an important drinking water source for Guiyang with a typical karstic limestone environment.The total phosphorus(TP) concentrations in the sediments ranged from 973.36 to 2334.18 mg/kg with a mean concentration of 1635.87 mg/kg(dry weight) ,and it was evident that the phosphorus level in the sediments was high compared with other eutrophic lakes such as Lake Chaohu and Lake Xihu.The results of the two methods,sequential extraction and XRD,demonstrated the presence of different phosphorus species in the lake sediments.Being compatible with local geophysical characteristics,the results of sequential extraction techniques indicate that the average percentages of dissolved phosphorus(DP) ,aluminum-bound phosphorus(Al-P) ,iron-bound phosphorus(Fe-P) ,calcium-bound phosphorus(Ca-P) and organic phosphorus(OP) in the sediments were 0.40%,7.06%,5.07%,45.48%and 38.49%,respectively.Notably,the concentrations of inorganic phosphorus(IP) were higher than those of OP,and the IP consisted primarily of Ca-P.The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable,inert and non-bioavailable phosphorus fraction.The results of XRD analysis indicated that,among phosphorus species,AlPO4 was found in all sediment samples at relatively high concentrations.Moreover,the TP concentrations in the sediments were high;thus the release potential and bioavailability of phosphorus in the sediments was important.Further statistical analyses of the results revealed significant correlations between phosphorus species in the sediments with two extractable principal components and four selectable cluster levels allowing interpretation of possible origins of phosphorus loading and transformation mechanisms of phosphorus species.Furthermore,available remediation measures were
基金Supported by Grants from the National Natural Science Foundation of China(No.81072879,No.81202754)National Basic Research Program of China(973 program,No.2015CB554500)+1 种基金Project of Shanghai Municipal Commission of Health and Family Planning(No.20144Y0153)Special Scientific Research Fund for Election and Cultivation of the Elite in College and University(No.szy10071)
文摘OBJECTIVE: To observe the effect of stimulating Qihai(CV 6) and bilateral Tianshu(ST 25) with herb-partitioned moxibustion(HPM) in rats with Crohn's disease(CD), and to investigate the possible anti-inflammatory mechanism of HPM.METHODS: Forty rats were randomly divided into four groups(n = 10 rats per group): normal control(NC), model control(MC), mesalamine(MES), and HPM. The CD rat model was established in the MC,MES, and HPM groups by administering a mixture of trinitrobenzenesulfonic acid and alcohol via enema. The HPM group received HPM on Qihai(CV 6)and bilateral Tianshu(ST 25), while the MES group received intragastric mesalamine. Colonic histomorphological scores, and serum concentrations of tumor necrosis factor α(TNF-α) and interleukin 1β(IL-1β) were assessed to evaluate the effects of HPM on colonic reparation and anti-inflammation.The expressions of Toll-like receptor 4(TLR-4), nuclear factor κB inhibitor α(IκB-α), IκB kinase α/β(IKKα/β), and NF-κB p65 were further analyzed to investigate the regulatory effects of the interventions on the TLR4/NF-κB pathway.RESULTS: CD rats showed inflammatory colonic damage and increased serum concentrations of TNF-α and IL-1β. The expressions of TLR4, IKKα/β,and NF-κB p65 in the colons of CD rats were significantly increased compared with the NC group,while the expression of IκBα(a key negative regulator of NF-κB p65) was decreased. HPM significantly mitigated colonic damage and reduced the serum concentrations of TNF-α and IL-1β. HPM downregulated the expressions of TLR4, IKKα/β, and NF-κB p65 in the colon, and upregulated the expression of IκBα. The effects of HPM in CD rats were similar to those of mesalamine.CONCLUSION: HPM alleviates colonic inflammation in CD rats. This may be achieved through regulation of TLR4, which induces NF-κB signal transduction.
基金Fujian Medical Innovation Project(Grant No.2017-CX-31)Guidance Project of Fujian Science and Technology Department(Grant No.2017Y0033).
文摘Clinical guidelines recommend a steady-state vancomycin(VCM)trough concentration(SVTC)of 10–15 mg/L for regular infections and 15–20 mg/L for severe infections.However,clinical trials have shown that increasing SVTC is not beneficial for efficacy,and instead it leads to nephrotoxicity.To verify whether increasing the SVTC results in improved clinical outcomes with sustainable adverse effects,we prospectively determined its correlation with clinical efficacy and safety.The participants included patients hospitalized with Gram-positive bacterial infections from March 2017 through October 2018.The patients were classified into group I(SVTC<10 mg/L),II(10≤SVTC≤20 mg/L),or III(SVTC>20 mg/L).Clinical,microbiological,and laboratory data were collected.Clinical outcomes between group I and II were matched after propensity score matching(PSM).A total of 331 patients were included in this study.Clinical failure occurred in 59(29%)of 204 patients on day 14,with no significant difference between groups I and II(P=0.535).Infection recurred at 28 d in 62(30%)of 204 patients,and no significant difference in infection recurrence was observed between both the groups(log-rank,P=0.674).Except for a significant increase in the incidence of acute kidney injury in group II,no significant difference was observed between two groups for any clinical results.The incidence of adverse events in groups I and II was significantly lower than that in group III(P<0.001).SVTC had an applicable cut-off point at 14.55 mg/L.SVTC was not correlated with VCM clinical efficacy,while it was a good indicator of nephrotoxicity.
基金National Natural Science Foundation of China(62005248,62075193)Natural Science Foundation of Zhejiang Province(LD22F050002)Major Scientific Project of Zhejiang Laboratory(2019MB0AD01,2022MB0AL02)
文摘The nanomechanical resonator based on a levitated particle exhibits unique advantages in the development of ultrasensitive electric field detectors. We demonstrate a three-dimensional, high-sensitivity electric field measurement technology using the optically levitated nanoparticle with known net charge. By scanning the relative position between nanoparticle and parallel electrodes, the three-dimensional electric field distribution with microscale resolution is obtained. The measured noise equivalent electric intensity with charges of 100e reaches the order of 1 μV·cm^(-1)·Hz^(-1/2)at 1.4 × 10^(-7) mbar. Linearity analysis near resonance frequency shows a measured linear range over 91 d B limited only by the maximum output voltage of the driving equipment. This work may provide an avenue for developing a high-sensitivity electric field sensor based on an optically levitated nano-resonator.
基金supported by the National Natural Science Foundation of China(Grant No.41921005)the Major Project of High Resolution Earth Observation System(Grant No.30Y60B01-9003-22/23)+1 种基金the New Cornerstone Science Foundation through the XPLORER PRIZEthe Tsinghua University Initiative Scientific Research Program(Grant No.20223080041)。
文摘CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source categories.Here,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local statistics.Global CO_(2)emissions from fossil fuel combustion and cement production in 1970–2021 were then estimated with highly-resolved source category(1,484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021 were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission accounting.With the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate mitigation.Remarkable differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different regions.Our estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small emitters.Our database,named the Multiresolution Emission Inventory model for Climate and air pollution research(MEIC)is publicly available through http://meicmodel.org.cn with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate research.
基金Supported by the National Natural Science Foundation of China(Mechanism of Acupuncture Up-regulating HLA-G/E to Regulate Maternal-fetal Immune Tolerance and Promote Embryo Implantation,No.81202757)
文摘OBJECTIVE: To assess the effectiveness of acupuncture for the treatment of functional constipation(FC).METHODS: The literature was searched for randomized controlled trials(RCTs) comparing acupuncture with medical treatment; no medical treatment,placebo acupuncture, and sham acupuncture in patients with FC were searched. Data were extracted by two independent reviewers using standard data extraction forms. Risk of bias for each RCT was assessed using a modified Oxford 5-point quality scale. Data were pooled according to intervention and treatment course. Parameters evaluated included effectiveness/invalidity, Cleveland Clinic score(CCS), colon transit time(CTT) and adverse effects.RESULTS: Nineteen studies involving 1679 participants were eligible for inclusion; of these studies,16 were published in Chinese and three in English.Risks of bias were high. Acupuncture was significantly superior to medication therapy in short-term(effectiveness/invalidity, P = 0.0009; CCS, P = 0.02)and long-term(effectiveness/invalidity, P = 0.004;CCS, P = 0.04; CCT, P < 0.0001) effectiveness. A short treatment course of less than 15 days was sufficient. The likelihood of adverse effects was significantly lower for acupuncture than for medication therapy(P = 0.002).CONCLUSION: Compared with medication, acupuncture was more effective and had a lower adverse effect rate in the treatment of FC. A short treatment course of two weeks was sufficient for a good effect. However, the poor quality of the included trials indicates the need for well-designed RCTs, including adequate sample size and a reasonable placebo control, to assess the effectiveness of acupuncture for FC.
基金Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences,Grant/Award Number:2017-I2M-1-009Peking Union Medical College Innovation Fund for Graduate Students,Grant/Award Number:2018-1002-01-21.
文摘Background:Cancer has become a global health problem,and assessments of cancer mortality are important for effective public health policy-making and adequate resource allocation.In this study,we aimed to predict the mortality rates and numbers of deaths related to four common cancers(lung,liver,stomach,and esophagus)in China from 2020 to 2030 and to estimate the corresponding cancer burden caused by population aging and tobacco smoking.Methods:Cancer mortality data(2004-2017)were extracted from China’s death surveillance datasets,and China’s population figures(2020-2030)were obtained from the United Nations population projections.Smoking prevalence data were retrieved from a World Health Organization global report,and relative risks of smoking and cancers were derived from large-scale Asian studies.We predicted the deaths related to the four major cancers and age-standardized mortality rates using joinpoint regression and linear regression models.The tobacco smoking related burden of these four major cancers was estimated using the population attributable fraction.Results:Unlike lung cancer mortality which was predicted to continue to increase,the age-standardized mortality rates for digestive cancers(liver,stomach,and esophageal cancers)are predicted to decline over the next decade.The number of deaths caused by the four major cancers is predicted to increase from 1,490,304 in 2020 to 1,823,960 in 2030.The age-specific mortality rates of the four major cancers are predicted to increase with age after 40-45 years,peaking in the age groups of 80-84 and ≥85 years.In 2030,the combined number of deaths from the four examined cancers among adults aged ≥65 years is predicted to be 1,167,153,accounting for 64% of all deaths from these cancers.Tobacco smoking is predicted to contribute to nearly 29% of deaths fromthese cancers,corresponding to 527,577 deaths.Conclusions:The overall trend in the combined total mortality from four major cancers is predicted to decline over the next decade;however,the corresponding
基金supported by the National Natural Science Foundation of China under Grant Nos.70871108, 70810107020
文摘There has been considerable debate about the major factors responsible for the dramatic decline of China＇s energy intensity in the 1980s and 1990s. However, few detailed analysis has been done to explain the fluctuation in energy intensity during 2002-005. In this paper, we use the structural decomposition analysis （SDA） to decompose energy intensity into five determining factors： Energy input coefficient, technology coefficient （Leontief inverse coefficient）, final demands structure by product, final demands by category and final energy consumption coefficient. We then further decompose two coefficients, energy input coefficient and technology coefficient, into structure and real coefficient. Empirical study is carried out based on the energy-input-output tables from 1987 to 2005 in 2000 constant price. The results show that between 1987 and 2002, energy input structure accounts for most of the decline in energy intensity. However, the input structure and final demands structure by product explain the increase of the energy intensity between 2002 and 2005.
基金the Zhejiang Public Welfare Technology Application Research Project(LGF22E080021)Ningbo Natural Science Foundation Project(202003N4169)+2 种基金Natural Science Foundation of China(11202138,52008215)the Natural Science Foundation of Zhejiang Province,China(LQ20E080013)the Major Special Science and Technology Project(2019B10076)of“Ningbo Science and Technology Innovation 2025”.
文摘Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use of structures.The main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage assessment.However,for many shear-type structures,it is difficult to obtain accurate FEM.In order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this paper.This method only needs to measure a few low-order vibration modes of the structure.The proposed defect diagnosis method is divided into two stages.In the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after damage.In the second stage,damage severity is evaluated based on an improved frequency sensitivity equation.Themain innovations of this method lie in two aspects.The first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear structure.The second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite elementmodel.Thismethod has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear structure.Based on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element modeling.The proposed method should be a very simple and practical defect diagnosis technique in engineering practice.
文摘This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization,including building bridges,accelerating the transformation of achievements,promoting the value-added of the whole agricultural industry chain,and promoting the rapid development of rural industrial economy.It also discusses the working achievements of science and technology commissioners,in order to promote further development of rural revitalization in Guangdong Province.
