期刊文献+
共找到7,198篇文章
< 1 2 250 >
每页显示 20 50 100
Grain yield and N uptake of maize in response to increased plant density under reduced water and nitrogen supply conditions 被引量:2
1
作者 Jingui Wei Qiang Chai +5 位作者 Wen Yin Hong Fan Yao Guo Falong Hu Zhilong Fan QimingWang 《Journal of Integrative Agriculture》 SCIE CSCD 2024年第1期122-140,共19页
The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.H... The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas. 展开更多
关键词 water and N reduction plant density MAIZE grain yield N uptake compensation effect
下载PDF
COVID-19 Vaccination Uptake and Associated Factors in Selected Communities in Two Southwestern States in Nigeria
2
作者 Oluseye Ayodele Ajayi Olabanjo Okunlola Ogunsola +4 位作者 Ajibola Idowu Oluwaseun Kikelomo Ajayi Kucheli Wudiri Rita Asoka-Ikechukwu Prosper Okonkwo 《Advances in Infectious Diseases》 CAS 2024年第1期260-278,共19页
Introduction: COVID-19 vaccine uptake and acceptance have been a major global concern due to the prevalent misinformation and disinformation that has characterized the vaccine rollout worldwide. This study aimed to as... Introduction: COVID-19 vaccine uptake and acceptance have been a major global concern due to the prevalent misinformation and disinformation that has characterized the vaccine rollout worldwide. This study aimed to assess COVID-19 vaccine uptake and acceptance, and associated factors among selected community members in two states in southwestern Nigeria. Method: We conducted a cross-sectional study using a multistage sampling technique. Fifty catchment settlements of 10 health facilities in each of Oyo and Ogun States targeted for a COVID-19 infection prevention and control intervention were randomly selected. Four households were targeted per settlement. All households that refused access were replaced, to ensure a minimum of four households randomly selected per settlement. The primary household decision-maker was interviewed in each household. Information elicited included respondents’ sociodemographic characteristics, health history, knowledge, risk and benefit perception about the COVID-19 vaccine, vaccine uptake, and willingness to be vaccinated. The study was conducted from July–August 2021. Data were analyzed using SPSS IBM version 23. Result: Four hundred household decision-makers were surveyed in Oyo and Ogun states, after replacement. The mean age of the respondents was 43.0 ± 11.0 years. The majority, 346 (86.5%) had heard about COVID-19 vaccination, but only 47 (13.6%) had received a COVID-19 vaccination. Of the 299 respondents who reported not receiving a COVID-19 vaccination, 166 (55.5%) were willing to be vaccinated. In  univariate analysis, respondents who were female had tertiary education, perceived that COVID-19 vaccines are free and accessible, perceived that COVID-19 vaccines have minimal side effects, and perceived higher benefits of COVID-19 vaccination had higher odds of being vaccinated. In contrast, younger respondents, respondents with higher knowledge scores on COVID-19 preventive measures, and with chronic illness had lower likelihoods of being vaccinated. In multivariate analysis, only the respondent’s age, perception score on COVID-19 vaccine benefits, knowledge score on IPC measures, and positive response on accessibility and safety were significant after adjusting for other factors. Conclusion: COVID-19 vaccine uptake rate as well as willingness to receive vaccination were low in the study setting. There is an urgent need for policymakers to embark on well-designed campaigns to address barriers to COVID-19 vaccination to increase vaccine uptake. 展开更多
关键词 COVID-19 VACCINATION VACCINE Vaccine uptake
下载PDF
Impact of different interaction behavior on epidemic spreading in time-dependent social networks
3
作者 黄帅 陈杰 +2 位作者 李梦玉 徐元昊 胡茂彬 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期190-195,共6页
We investigate the impact of pairwise and group interactions on the spread of epidemics through an activity-driven model based on time-dependent networks.The effects of pairwise/group interaction proportion and pairwi... We investigate the impact of pairwise and group interactions on the spread of epidemics through an activity-driven model based on time-dependent networks.The effects of pairwise/group interaction proportion and pairwise/group interaction intensity are explored by extensive simulation and theoretical analysis.It is demonstrated that altering the group interaction proportion can either hinder or enhance the spread of epidemics,depending on the relative social intensity of group and pairwise interactions.As the group interaction proportion decreases,the impact of reducing group social intensity diminishes.The ratio of group and pairwise social intensity can affect the effect of group interaction proportion on the scale of infection.A weak heterogeneous activity distribution can raise the epidemic threshold,and reduce the scale of infection.These results benefit the design of epidemic control strategy. 展开更多
关键词 epidemic transmission complex network time-dependent networks social interaction
下载PDF
A process-oriented approach for identifying potential landslides considering time-dependent behaviors beyond geomorphological features
4
作者 Xiang Sun Guoqing Chen +4 位作者 Xing Yang Zhengxuan Xu Jingxi Yang Zhiheng Lin Yunpeng Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期961-978,共18页
Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential lands... Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential landslide identification that considers time-dependent behaviors.The method integrates comprehensive remote sensing and geological analysis to qualitatively assess slope stability,and employs numerical analysis to quantitatively calculate aging stability.Specifically,a time-dependent stability calculation method for anticlinal slopes is developed and implemented in discrete element software,incorporating time-dependent mechanical and strength reduction calculations.By considering the time-dependent evolution of slopes,this method highlights the importance of both geomorphological features and time-dependent behaviors in landslide identification.This method has been applied to the Jiarishan slope(JRS)on the Qinghai-Tibet Plateau as a case study.The results show that the JRS,despite having landslide geomorphology,is a stable slope,highlighting the risk of misjudgment when relying solely on geomorphological features.This work provides insights into the geomorphological characterization and evolution history of the JRS and offers valuable guidance for studying slopes with similar landslide geomorphology.Furthermore,the process-oriented method incorporating timedependent evolution provides a means to evaluate potential landslides,reducing misjudgment due to excessive reliance on geomorphological features. 展开更多
关键词 Geomorphological features Evolution history time-dependent stability calculation Landslides identification Qinghai-Tibet Plateau
下载PDF
Socio-Demographic and Economic Factors Associated with Uptake of COVID-19 Vaccine among Pregnant Women at Pumwani Maternity Hospital in Nairobi County, Kenya
5
作者 Nyawela S. Nyibil Gideon Kikuvi Isabel Kazanga Chiumia 《Open Journal of Epidemiology》 2024年第2期221-237,共17页
Introduction: Pregnant women are a highly vulnerable population for COVID-19 with increased risk of hospitalization, intensive-care unit admission, invasive ventilation support, and mortality. Objective: This study de... Introduction: Pregnant women are a highly vulnerable population for COVID-19 with increased risk of hospitalization, intensive-care unit admission, invasive ventilation support, and mortality. Objective: This study determined the socio-demographic and economic factors associated with the uptake of COVID-19 vaccine among pregnant women utilizing antenatal care services in Pumwani Maternity Hospital, Nairobi County-Kenya. Methods: The study was carried out from 15 June to 23 July 2023. Systematic sampling was used to select 302 women from whom data was collected through face-to-face interviews using a pre-tested semi-structured questionnaire. Data was analyzed using SPSS software in which bivariate and multivariate logistic regression analyses were done at a significance level of p Results: A total of 302 pregnant women participated in the study. Of these, 105 (34.8%) were aged between twenty-six (26) and thirty (30) years. The mean age of the women was 28.60 ± (SD = 5.297). The uptake of the COVID-19 vaccine was 41.1%. The common side effects reported to be associated with the vaccines were fever, headache, joint pain, vomiting and skin rash. Uptake of the COVID-19 vaccine was significantly associated with being married (AOR = 3.65, 95% CI: 0.62 - 1.80, p = 0.001), having a secondary level of education (AOR = 3.78, 95% CI: 0.99 - 2.88, p = 0.001) and being employed (COR = 2.66, 95% CI: 1.31 - 3.06, p = 0.001). Conclusion: COVID-19 vaccination uptake remains low among pregnant women in seeking ANC in Nairobi. The individual factors associated with the uptake of COVID-19 vaccine among pregnant Women at Pumwani maternity hospital in Nairobi County were being married, having secondary level of education and being employed. Integration of the COVID-19 vaccine with other routine vaccinations as per the national immunization program in Kenya and the enhancement of education regarding the safety and efficacy of the COVID-19 vaccine in pregnancy and breastfeeding and economic empowerment of women are recommended. 展开更多
关键词 COVID-19 Vaccine uptake Associated Factors Pregnant Women
下载PDF
Methods,Mechanisms,and Application Prospects for Enhancing Extracellular Vesicle Uptake
6
作者 Ying-peng XU Tao JIANG +1 位作者 Xiao-fan YANG Zhen-bing CHEN 《Current Medical Science》 SCIE CAS 2024年第2期247-260,共14页
Extracellular vesicles(EVs)are considered to be a new generation of bioinspired nanoscale drug delivery systems due to their low immunogenicity,natural functionality,and excellent biocompatibility.However,limitations ... Extracellular vesicles(EVs)are considered to be a new generation of bioinspired nanoscale drug delivery systems due to their low immunogenicity,natural functionality,and excellent biocompatibility.However,limitations such as low uptake efficiency,insufficient production,and inhomogeneous performance undermine their potential.To address these issues,numerous researchers have put forward various methods and applications for enhancing EV uptake in recent decades.In this review,we introduce various methods for the cellular uptake of EVs and summarize recent advances on the methods and mechanisms for enhancing EV uptake.In addition,we provide further understanding regarding enhancing EV uptake and put forward prospects and challenges for the development of EV-based therapy in the future. 展开更多
关键词 extracellular vesicles EXOSOMES extracellular vesicle uptake extracellular vesiclebased therapy
下载PDF
Combined application of organic fertilizer and chemical fertilizer alleviates the kernel position effect in summer maize by promoting post-silking nitrogen uptake and dry matter accumulation
7
作者 Lichao Zhai Lihua Zhang +7 位作者 Yongzeng Cui Lifang Zhai Mengjing Zheng Yanrong Yao Jingting Zhang Wanbin Hou Liyong Wu Xiuling Jia 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1179-1194,共16页
Adjusting agronomic measures to alleviate the kernel position effect in maize is important for ensuring high yields.In order to clarify whether the combined application of organic fertilizer and chemical fertilizer(CA... Adjusting agronomic measures to alleviate the kernel position effect in maize is important for ensuring high yields.In order to clarify whether the combined application of organic fertilizer and chemical fertilizer(CAOFCF)can alleviate the kernel position effect of summer maize,field experiments were conducted during the 2019 and 2020 growing seasons,and five treatments were assessed:CF,100%chemical fertilizer;OFCF1,15%organic fertilizer+85%chemical fertilizer;OFCF2,30%organic fertilizer+70%chemical fertilizer;OFCF3,45%organic fertilizer+55%chemical fertilizer;and OFCF4,60%organic fertilizer+40%chemical fertilizer.Compared with the CF treatment,the OFCF1 and OFCF2 treatments significantly alleviated the kernel position effect by increasing the weight ratio of inferior kernels to superior kernels and reducing the weight gap between the superior and inferior kernels.These effects were largely due to the improved filling and starch accumulation of inferior kernels.However,there were no obvious differences in the kernel position effect among plants treated with CF,OFCF3,or OFCF4 in most cases.Leaf area indexes,post-silking photosynthetic rates,and net assimilation rates were higher in plants treated with OFCF1 or OFCF2 than in those treated with CF,reflecting an enhanced photosynthetic capacity and improved postsilking dry matter accumulation(DMA)in the plants treated with OFCF1 or OFCF2.Compared with the CF treatment,the OFCF1 and OFCF2 treatments increased post-silking N uptake by 66.3 and 75.5%,respectively,which was the major factor driving post-silking photosynthetic capacity and DMA.Moreover,the increases in root DMA and zeatin riboside content observed following the OFCF1 and OFCF2 treatments resulted in reduced root senescence,which is associated with an increased post-silking N uptake.Analyses showed that post-silking N uptake,DMA,and grain yield in summer maize were negatively correlated with the kernel position effect.In conclusion,the combined application of 15-30%organic fertilizer and 70-85%chemical fertilizer alleviated the kernel position effect in summer maize by improving post-silking N uptake and DMA.These results provide new insights into how CAOFCF can be used to improve maize productivity. 展开更多
关键词 chemical fertilizer dry mater accumulation kernel position effect N uptake organic fertilizer
下载PDF
Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat
8
作者 Jingui Wei Zhilong Fan +5 位作者 Falong Hu Shoufa Mao Fang Yin Qiming Wang Qiang Chai Wen Yin 《The Crop Journal》 SCIE CSCD 2024年第4期1222-1232,共11页
Achieving the green development of agriculture requires the reduction of chemical nitrogen(N)fertilizer input.Previous studies have confirmed that returning green manure to the field is an effective measure to improve... Achieving the green development of agriculture requires the reduction of chemical nitrogen(N)fertilizer input.Previous studies have confirmed that returning green manure to the field is an effective measure to improve crop yields while substituting partial chemical N fertilizer.However,it remains unclear how to further intensify the substituting function of green manure and elucidate its underlying agronomic mechanism.In a split-plot field experiment in spring wheat,different green manures returned to the field under reduced chemical N supply was established in an oasis area since 2018,in order to investigate the effect of green manure and reduced N on grain yield,N uptake,N use efficiency(NUE),N nutrition index,soil organic matter,and soil N of wheat in 2020-2022.Our results showed that mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer without reducing grain yield or N accumulation.Noteworthily,mixed sown common vetch and hairy vetch under reduced N by 20%showed the highest N agronomy efficiency and recovery efficiency,which were 92.0%and 46.0%higher than fallow after wheat harvest and conventional N application rate,respectively.The increase in NUE of wheat was mainly attributed to mixed sown common vetch and hairy vetch,which increased N transportation quantity and transportation rate at pre-anthesis,enhanced N harvest index,optimized N nutrition index,and increased activities of nitrate reductase and glutamine synthetase of leaf,respectively.Meanwhile,mixed sown common vetch and hairy vetch under reduced N by 20%improved soil organic matter and N contents.Therefore,mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer while maintaining grain yield and N accumulation,and it combined with reduced chemical N by 20%or 40%improved NUE of wheat via enhancing N supply and uptake. 展开更多
关键词 Legume green manure Reduced N input WHEAT N uptake and supply Agronomic mechanism
下载PDF
Modeling time-dependent mechanical behavior of hard rock considering excavation-induced damage and complex 3D stress states
9
作者 Peiyang Yu Xiuli Ding +3 位作者 Peng-Zhi Pan Shuting Miao Zhaofeng Wang Shuling Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4046-4065,共20页
To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main compon... To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main components:a 3D viscoplastic isotropic constitutive relation that considers excavation damage and complex stress state,a quantitative relationship between critical irreversible deformation and complex stress state,and evolution characteristics of strength parameters.The proposed model is implemented in a self-developed numerical code,i.e.CASRock.The reliability of the model is validated through experiments.It is indicated that the time-dependent fracturing potential index(xTFPI)at a given time during the attenuation creep stage shows a negative correlation with the extent of excavationinduced damage.The time-dependent fracturing process of rock demonstrates a distinct interval effect of the intermediate principal stress,thereby highlighting the 3D stress-dependent characteristic of the model.Finally,the influence of excavation-induced damage and intermediate principal stress on the time-dependent fracturing characteristics of the surrounding rocks around the tunnel is discussed. 展开更多
关键词 Hard rock Excavation damage Complex stress state Three-dimensional(3D)time-dependent model
下载PDF
A GENERALIZED SCALAR AUXILIARY VARIABLE METHOD FOR THE TIME-DEPENDENT GINZBURG-LANDAU EQUATIONS
10
作者 司智勇 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期650-670,共21页
This paper develops a generalized scalar auxiliary variable(SAV)method for the time-dependent Ginzburg-Landau equations.The backward Euler method is used for discretizing the temporal derivative of the time-dependent ... This paper develops a generalized scalar auxiliary variable(SAV)method for the time-dependent Ginzburg-Landau equations.The backward Euler method is used for discretizing the temporal derivative of the time-dependent Ginzburg-Landau equations.In this method,the system is decoupled and linearized to avoid solving the non-linear equation at each step.The theoretical analysis proves that the generalized SAV method can preserve the maximum bound principle and energy stability,and this is confirmed by the numerical result,and also shows that the numerical algorithm is stable. 展开更多
关键词 time-dependent Ginzburg-Landau equation generalized scalar auxiliary variable algorithm maximum bound principle energy stability
下载PDF
Prevalence and Individual-Level Determinants of Uptake of Three or More Doses of Sulphadoxine-Pyrimethamine for Intermittent Preventive Treatment of Malaria in Pregnancy in Busia County, Kenya
11
作者 Anne Nduta Miatu Betsy Rono Cheriro Kamija Samuel Phiri 《Open Journal of Epidemiology》 2024年第3期405-418,共14页
Background: Malaria in pregnancy causes maternal anemia, low birth weight, intrauterine growth retardation, and preterm deliveries. In malaria-endemic regions in Kenya, percentage of pregnant women hospitalized with m... Background: Malaria in pregnancy causes maternal anemia, low birth weight, intrauterine growth retardation, and preterm deliveries. In malaria-endemic regions in Kenya, percentage of pregnant women hospitalized with malaria reach up to 60%. WHO recommends at least three doses of sulphadoxine pyrimethamine for Intermittent Preventive Treatment of Malaria in Pregnancy (IPTp) antenatally. This study sought to ascertain the prevalence and individual-level factors influencing the uptake of IPTp-SP3+. Methods: A facility-based cross-sectional study at Busia County Referral Hospital. 384 mothers were consecutively sampled at the maternity unit during delivery. Semi-structured questionnaires were used to collect data. Odds ratio (OR) and adjusted OR were used to determine statistical significance of individual factors influencing uptake of three or more IPTp-SP. Results: 43.0% of participants took IPTp-SP3+. Individual factors that affected the uptake of IPTp-SP3+ included starting ANC visits in the first trimester (adjusted odds ratio (aOR) = 2.1, 95% CI: 1.23 – 3.67, p = 0.046), having more than four ANC visits (aOR = 3.1, 95% CI: 1.49 – 6.50, p = 0.002), having a higher monthly income (aOR = 2.6, 95% CI: 1.24 – 5.36, p = 0.012), being aware of the advantages of IPTp-SP medications (aOR = 3.7, 95% CI: 1.40 – 9.74, p = 0.008), and having a positive attitude toward ANC services (aOR = 3.2, 95% CI: 1.61 – 6.31, p = 0.001). Conclusion: Less than half of the pregnant mothers are complyingIPTp-SP3+. There should be aggressive efforts by the County and National Ministries of Health promoting initiation of ANC attendance early and attendance of all the recommended eight visits together with ensuring availability of the drugs. 展开更多
关键词 Malaria in Pregnancy Antenatal Clinic Intermittent Prevention of Malaria in Pregnancy DOSAGE uptake Sulphadoxine-Pyrimethamine and Individual Level Factors
下载PDF
Thermomechanical Dynamics (TMD) and Bifurcation-Integration Solutions in Nonlinear Differential Equations with Time-Dependent Coefficients
12
作者 Hiroshi Uechi Lisa Uechi Schun T. Uechi 《Journal of Applied Mathematics and Physics》 2024年第5期1733-1743,共11页
The new independent solutions of the nonlinear differential equation with time-dependent coefficients (NDE-TC) are discussed, for the first time, by employing experimental device called a drinking bird whose simple ba... The new independent solutions of the nonlinear differential equation with time-dependent coefficients (NDE-TC) are discussed, for the first time, by employing experimental device called a drinking bird whose simple back-and-forth motion develops into water drinking motion. The solution to a drinking bird equation of motion manifests itself the transition from thermodynamic equilibrium to nonequilibrium irreversible states. The independent solution signifying a nonequilibrium thermal state seems to be constructed as if two independent bifurcation solutions are synthesized, and so, the solution is tentatively termed as the bifurcation-integration solution. The bifurcation-integration solution expresses the transition from mechanical and thermodynamic equilibrium to a nonequilibrium irreversible state, which is explicitly shown by the nonlinear differential equation with time-dependent coefficients (NDE-TC). The analysis established a new theoretical approach to nonequilibrium irreversible states, thermomechanical dynamics (TMD). The TMD method enables one to obtain thermodynamically consistent and time-dependent progresses of thermodynamic quantities, by employing the bifurcation-integration solutions of NDE-TC. We hope that the basic properties of bifurcation-integration solutions will be studied and investigated further in mathematics, physics, chemistry and nonlinear sciences in general. 展开更多
关键词 The Nonlinear Differential Equation with time-dependent Coefficients The Bifurcation-Integration Solution Nonequilibrium Irreversible States Thermomechanical Dynamics (TMD)
下载PDF
Phosphorylation regulation of nitrogen,phosphorus,and potassium uptake systems in plants 被引量:1
13
作者 Dongli Hao Xiaohui Li +4 位作者 Weiyi Kong Rongrong Chen Jianxiu Liu Hailin Guo Jinyan Zhou 《The Crop Journal》 SCIE CSCD 2023年第4期1034-1047,共14页
The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their reg... The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their regulators determine their ultimate activity.Elucidating the mechanism by which protein phosphorylation modification regulates nutrient uptake will advance plant breeding for high nutrientuse efficiency.In this review,it is concluded that the root nutrient absorption system is composed of several,but not all,members of a specific ion transporter or channel family.Under nutrient-starvation conditions,protein phosphorylation-based regulation of these proteins and associated transcription factors increases ion transporter-or channel-mediated nutrient uptake capacity via direct function activity enhancement,allowing more protein trafficking to the plasma membrane,by strengthening the interaction of transporters and channels with partner proteins,by increasing their protein stability,and by transcriptional activation.Under excessive nutrient conditions,protein phosphorylation-based regulation suppresses nutrient uptake by reversing these processes.Strengthening phosphorylation regulation items that increase nutrient absorption and weakening phosphorylation modification items that are not conducive to nutrient absorption show potential as strategies for increasing nutrient use efficiency. 展开更多
关键词 Ammonium uptake machinery Nitrate uptake machinery Phosphate uptake machinery Potassium uptake machinery Transcription factors Protein phosphorylation
下载PDF
Sample size adaptive strategy for time-dependent Monte Carlo particle transport simulation 被引量:3
14
作者 Dan-Hua ShangGuan Wei-Hua Yan +3 位作者 Jun-Xia Wei Zhi-Ming Gao Yi-Bing Chen Zhi-Cheng Ji 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第4期127-134,共8页
When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain... When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain important cases. This study proposes an adaptive strategy for automatically adjusting the sample size to fulfil more reasonable simulations. This is realized based on an extension of the Shannon entropy concept and is essentially different from the popular methods in timeindependent Monte Carlo particle transport simulations, such as controlling the sample size according to the relative error of a target tally or by experience. The results of the two models show that this strategy can yield almost similar results while significantly reducing the calculation time. Considering the efficiency, the sample size should not be increased blindly if the efficiency cannot be enhanced further. The strategy proposed herein satisfies this requirement. 展开更多
关键词 time-dependent Monte Carlo particle transport simulation Shannon entropy Adaptive strategy
下载PDF
Potassium nutrition of maize:Uptake,transport,utilization,and role in stress tolerance 被引量:2
15
作者 Meiling Zhang Yingying Hu +3 位作者 Wu Han Jian Chen Jinsheng Lai Yi Wang 《The Crop Journal》 SCIE CSCD 2023年第4期1048-1058,共11页
Potassium(K) is an essential macronutrient for plant growth and development and influences yield and quality of agricultural crops.Maize(Zea mays) is one of the most widely distributed crops worldwide.In China,althoug... Potassium(K) is an essential macronutrient for plant growth and development and influences yield and quality of agricultural crops.Maize(Zea mays) is one of the most widely distributed crops worldwide.In China,although maize consumes a large amount of K fertilizer,the K uptake/utilization efficiency(KUE)of maize cultivars is relatively low.Elucidation of KUE mechanisms and development of maize cultivars with higher KUE are needed.Maize KUE is determined by K+uptake,transport,and remobilization,which depend on a variety of K+channels and transporters.We review basic information about K+channels and transporters in maize,their functions and regulation,and the roles of K+in nitrogen transport,sugar transport,and salt tolerance.We discuss challenges and prospects for maize KUE improvement. 展开更多
关键词 MAIZE POTASSIUM CHANNEL TRANSPORTER K uptake/utilization efficiency
下载PDF
Accumulation of silicon in shoots is required for reducing lead uptake in rice 被引量:1
16
作者 Xiuxiu Gong Fan Yang +1 位作者 Xianyu Pan Jifeng Shao 《The Crop Journal》 SCIE CSCD 2023年第4期1261-1271,共11页
Silicon(Si) treatment has been shown to reduce the toxicity and accumulation of lead(Pb) in many plants,including rice.The mechanisms responsible for this effect are poorly understood.We investigated the effects of Si... Silicon(Si) treatment has been shown to reduce the toxicity and accumulation of lead(Pb) in many plants,including rice.The mechanisms responsible for this effect are poorly understood.We investigated the effects of Si treatment on Pb toxicity and accumulation in two rice mutants(lsi1 and lsi2) defective in Si uptake and in their wild types.Si did not alleviate Pb-induced inhibition of root elongation in shortterm experiments,but reduced Pb accumulation in wild types,but not in mutants,in long-term experiments.Pre-treatment with Si reduced Pb concentration in xylem sap and Pb accumulation in wild types but not in mutants.In split-root experiments,Si treatment reduced Pb accumulation but did not alter Pb localization in roots.Si treatment suppressed the expression of many genes encoding proteins that may participate in Pb uptake and transport in the wild type,but not in the lsi1 mutant.These results indicate that Si accumulation in shoots is required to reduce Pb uptake in rice and that the effect is achieved via Siinduced suppression of genes encoding proteins involved in Pb uptake and/or transport. 展开更多
关键词 SILICON LEAD RICE uptake Toxicity
下载PDF
Nε-(carboxymethyl)lysine promotes lipid uptake of macrophage via cluster of differentiation 36 and receptor for advanced glycation end products 被引量:1
17
作者 Zhong-Qun Wang Hai-Peng Yao Zhen Sun 《World Journal of Diabetes》 SCIE 2023年第3期222-233,共12页
BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell ... BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake. 展开更多
关键词 Nε-(carboxymethyl)lysine Cluster of differentiation 36 Receptor for advanced glycation end products Lipid uptake MACROPHAGE
下载PDF
Influence of Socioeconomic Profile on Uptake of Immunohistochemistry Services among Women with Breast Cancer Attending Tertiary Health Facilities
18
作者 Kingsley Chidi Anochiwa Sally Nkechinyere Onyeka Ibe +4 位作者 Eunice Anyalewechi Nwoke Onyinyechi Blessed Nworuh Asinobi Oluchi Darlington Chidi Amadi Emmanuel Okechukwu Nna 《Journal of Biosciences and Medicines》 2023年第10期126-135,共10页
Background: Breast cancer is the leading cause of death from cancer in women worldwide. It can be stratified by histological and immunopathological analysis as well as by molecular subtypes. Socioeconomic and cultural... Background: Breast cancer is the leading cause of death from cancer in women worldwide. It can be stratified by histological and immunopathological analysis as well as by molecular subtypes. Socioeconomic and cultural-mediated factors contribute to breast cancer heterogeneity and overall survivability. Objective: The aim of this study was to determine the influence of socioeconomic profile on the uptake of immunohistochemistry (IHC) services among women with breast cancer attending tertiary health facilities in Imo State. Methodology: This descriptive cross-sectional study was carried out among women with breast cancer in Imo State. The instrument for data collection used was a structured questionnaire constructed in line with the objectives of the study. A total of 121 respondents were selected randomly from a target study population of 891 using a systematic sampling technique. The software Statistical Package for Social Sciences (SPSS) version 21 was used for data analysis. Results: The mean age of the 121 respondents in this study was 45.2 ± 0.7 years. Age and education levels of the respondents were found to significantly influence the utilization of IHC services (P Conclusion: In our study, the consumption of IHC services was influenced significantly by the respondents’ age and level of education. Consequently, public health awareness programmes centred on the importance of IHC services in the management of breast cancer should be encouraged, so as to reach the less educationally endowed and older women in order to save more lives. 展开更多
关键词 Breast Cancer uptake IMMUNOHISTOCHEMISTRY Socioeconomics Profile Age Education
下载PDF
Nutrition Uptake among Pregnant Women: A Case of Solwezi District, North Western Province
19
作者 Prisca Womba Muchima Catherine M. Ngoma Natali Mbewe Shitima 《Open Journal of Obstetrics and Gynecology》 CAS 2023年第5期960-982,共23页
Background: Zambia has a population of 17.4 million people of which 48% are unable to meet their minimum calorie requirement and 35% of the children in Zambia are stunted (ZDHS, 2018). In the 2018 ZDHS report, 31% of ... Background: Zambia has a population of 17.4 million people of which 48% are unable to meet their minimum calorie requirement and 35% of the children in Zambia are stunted (ZDHS, 2018). In the 2018 ZDHS report, 31% of women aged 15 - 49 had anaemia. Most cases of anaemia in pregnancy are due to micronutrient deficiency and maternal malnutrition. The 2020 Zambia Global Nutrition Report shows an increase in the prevalence of anaemia among women of reproductive age (45%) and low birth weight infants (13.0%) which suggested a need to explore determinants of pregnant women’s nutrition uptake in order to improve the nutritional status of pregnant women particularly those in Solwezi district of the north-western province of Zambia. Methods: An analytical cross-sectional study was conducted on antenatal mothers aged 15 - 49 accessing routine antenatal care from four selected health facilities in Solwezi district from July 2021 to February 2021. Cluster sampling method was used to select the 4 health facilities and the 98 antenatal mothers were selected using systematic sampling method. Data was collected using a pretested researcher-assisted semi-structured questionnaire and analyzed using the SPSS version 26. Chi-square test was used to determine associations between the independent and independent variables. The level of significance was set at 0.05 and the confidence interval was set at 95%. Multiple logistic regression analysis was done to predict associations among variables. Results: The findings revealed that a large proportion of respondents (71.4 %) had high knowledge regarding nutrition during pregnancy compared to (19.4%) and (9.2%) who expressed medium and low knowledge levels respectively. Attitude towards nutrition in pregnancy was positive in the majority, 82 (83.7%) of the respondents, and over half, (55%) of the respondents reported good nutrition uptake during pregnancy. Conclusions: In this study, nutrition uptake in pregnancy was significantly associated with women’s attitudes towards nutrition. It was also observed that more respondents who had a positive attitude towards nutrition had good nutrition uptake during pregnancy. We can therefore, conclude that the research study has revealed that majority of the respondents had high knowledge level and positive attitudes towards nutrition during pregnancy and only half of the respondents had good nutrition uptake during pregnancy which should be able to prompt all the stakeholders of health to focus their attention on behavioural change messages, policies and intervention in order to enhance good nutrition uptake among pregnant women. 展开更多
关键词 Pregnant Women Determinants Nutritional uptake Knowledge ATTITUDE PRACTICES
下载PDF
Influence of Cues to Action towards Uptake of Immunohistochemistry Services among Women with Breast Cancer Attending Tertiary Health Facilities
20
作者 Kingsley C. Anochiwa Sally Nkechinyere Onyeka Ibe +4 位作者 Eunice Anyalewechi Nwoke Okwuchi B. Nworuh Asinobi Oluchi Darlington Chidi Amadi Emmanuel Okechukwu Nna 《Journal of Biosciences and Medicines》 2023年第10期90-102,共13页
Background: Breast cancer is the most frequently diagnosed cancer among women, making it a significant global public health issue. Although developed countries have a higher incidence of breast cancer, developing coun... Background: Breast cancer is the most frequently diagnosed cancer among women, making it a significant global public health issue. Although developed countries have a higher incidence of breast cancer, developing countries like Nigeria have a low incidence rate but higher rates of morbidity and mortality from the disease. Objective: This study explored how cues to action influenced the use of immunohistochemistry by women in Imo State and how many of them used immunohistochemistry (IHC) to diagnose their condition. Methodology: We used a descriptive study methodology for the investigation, and 121 participants were chosen at random from the 891 total population. The respondents were chosen through a systematic sampling procedure. Structured questionnaire was used as the data collection tool, and the statistical software for social science (SPSS) was used to analyze the data. Results: The mean age of the 121 participants in the study was 45.2 ± 0.7 years. The study found that awareness of IHC services is a significant influencing factor for the uptake and health personnel is the major source of awareness of IHC services. Cues to action particularly from health workers, as well as knowledge of any victim of breast cancer and user of IHC services, also significantly influenced uptake of the IHC services (P Conclusion: In our study, utilization of IHC services was also impacted by cues to action, particularly from healthcare professionals, as well as awareness of any breast cancer victims and those who used IHC services thus cues to action is a major predicator of immunohistochemistry uptake among women with breast cancer. 展开更多
关键词 BREAST Cancer uptake IMMUNOHISTOCHEMISTRY Cues to Action
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部