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221.
Background
Cases of hemorrhagic fever with renal syndrome (HFRS) are widely distributed in eastern Asia, especially in China, Russia, and Korea. It is proved to be a difficult task to eliminate HFRS completely because of the diverse animal reservoirs and effects of global warming. Reliable forecasting is useful for the prevention and control of HFRS.Methods
Two hybrid models, one composed of nonlinear autoregressive neural network (NARNN) and autoregressive integrated moving average (ARIMA) the other composed of generalized regression neural network (GRNN) and ARIMA were constructed to predict the incidence of HFRS in the future one year. Performances of the two hybrid models were compared with ARIMA model.Results
The ARIMA, ARIMA-NARNN ARIMA-GRNN model fitted and predicted the seasonal fluctuation well. Among the three models, the mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of ARIMA-NARNN hybrid model was the lowest both in modeling stage and forecasting stage. As for the ARIMA-GRNN hybrid model, the MSE, MAE and MAPE of modeling performance and the MSE and MAE of forecasting performance were less than the ARIMA model, but the MAPE of forecasting performance did not improve.Conclusion
Developing and applying the ARIMA-NARNN hybrid model is an effective method to make us better understand the epidemic characteristics of HFRS and could be helpful to the prevention and control of HFRS. 相似文献222.
Effects of the Biocontrol Agent Aspergillus flavipes on the Soil Microflora and Soil Enzymes in the Rooting Zone of Pepper Plants Infected with Phytophthora capsici 总被引:1,自引:0,他引:1
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Changyuan Liu Li Liu Shuyi Yu Chunhao Liang Tianshu Guan Muhammad Irfan Kuihua Zhao 《Journal of Phytopathology》2015,163(7-8):513-521
This study examined the effect of ASD strain (Aspergillus flavipes), isolated from continuous cropping soil for pepper and named by the sampling position, on soil microflora and soil enzymes in rooting zone soil of healthy and diseased (Phytophthora capsici) pepper plants. Results showed that the ASD strain could significantly reduce the number of bacteria and actinomycetes, with a significant increase in fungi in the rhizosphere soil of both healthy and diseased plants. With increasing colonization time of the ASD strain, the number of bacteria and actinomycetes decreased initially and then increased gradually, while the number of fungi was first increased significantly and later decreased slowly. The soil enzyme activities of urease, acid phosphatase, invertase and dehydrogenase were significantly increased by the ASD strain, while the activity of catalase was not significantly increased. As time from inoculation with the ASD strain increased, the activities of various enzymes were higher than controls. Maximum enzyme activities were found on the tenth day after ADS inoculation. The response of soil enzyme activities affected by the ASD strain was as follows: urease > dehydrogenase > invertase > acid phosphatase > catalase. These results suggest that the biocontrol of ASD strain could improve the micro ecology of rhizosphere soil. 相似文献
223.
Zeyu Zhu Junfeng Lu Shuyi Wang Weijia Peng Yang Yang Chen Chen Xin Zhou Xifei Yang Wenjun Xin Xinyi Chen Jiakai Pi Wei Yin Lin Yao Rongbiao Pi 《Aging cell》2022,21(4)
Acrolein, an unsaturated aldehyde, is increased in the brain of Alzheimer''s disease (AD) patients and identified as a potential inducer of sporadic AD. Synaptic dysfunction, as a typical pathological change occurring in the early stage of AD, is most closely associated with the severity of dementia. However, there remains a lack of clarity on the mechanisms of acrolein inducing AD‐like pathology and synaptic impairment. In this study, acrolein‐treated primary cultured neurons and mice were applied to investigate the effects of acrolein on cognitive impairment and synaptic dysfunction and their signaling mechanisms. In vitro, ROCK inhibitors, Fasudil, and Y27632, could attenuate the axon ruptures and synaptic impairment caused by acrolein. Meanwhile, RNA‐seq distinct differentially expressed genes in acrolein models and initially linked activated RhoA/Rho‐kinase2 (ROCK2) to acrolein‐induced synaptic dysfunction, which could regulate neuronal cytoskeleton and neurite. The Morris water maze test and in vivo field excitatory postsynaptic potential (fEPSP) were performed to evaluate spatial memory and long‐term potential (LTP), respectively. Acrolein induced cognitive impairment and attenuated LTP. Furthermore, the protein level of Synapsin 1 and postsynaptic density 95 (PSD95) and dendritic spines density were also decreased in acrolein‐exposed mice. These changes were improved by ROCK2 inhibitor Fasudil or in ROCK2+/− mice. Together, our findings suggest that RhoA/ROCK2 signaling pathway plays a critical role in acrolein‐induced synaptic damage and cognitive dysfunction, suggesting inhibition of ROCK2 should benefit to the early AD. 相似文献
224.
225.
Shuyi Yu Robert H. Heflich Linda S. Von Tungeln Karam El-Bayoumy Fred F. Kadlubar Peter P. Fu 《Mutation research》1991,250(1-2):145-152
The mutations and DNA adducts produced by the environmental pollutant 2-nitropyrene were examined in Salmonella typhimurium tester strains. 2-Nitropyrene was a stronger mutagen than its extensively studied structural isomer 1-nitropyrene in strains TA96, TA97, TA98, TA100, TA102, TA104 and TA1538. Both 1- and 2-nitropyrene were essentially inactive in TA1535. The mutagenicity of 1- and 2-nitropyrene in TA98 was much higher than in TA98NR and the activity of these compounds in TA100 was much higher than in TA100NR. While 1-nitropyrene exhibited similar mutagenicity in strains TA98 and TA98/1,8-DNP6, the mutagenicity of 2-nitropyrene in TA98/1,8-DNP6 was much lower than in TA98. Analysis of DNA from TA96 and TA104 incubated with 2-nitropyrene indicated the presence of two adducts, N-(deoxyguanosin-8-yl)-2-aminopyrene and N-deoxyadenosin-8-yl)-2-aminopyrene. The results suggest that 2-nitropyrene is metabolized by bacterial nitroreductase(s) to N-hydroxy-2-aminopyrene, and possibly by activation to a highly mutagenic O-acetoxy ester. DNA adduct formation with deoxyguanosine and deoxyadenosine correlates with the mutagenicity of 2-nitropyrene in tester strains possessing both G:C and A:T mutational targets. 相似文献
226.
人肾上腺内肽能神经的超微结构 总被引:1,自引:0,他引:1
殷树仪 《中国组织化学与细胞化学杂志》1994,(1)
应用抗生蛋白链菌素一生物素一过氧化物酶复合物的免疫电镜技术,在相邻切片中,分别观察人肾上腺内NPY、VIP、SP和CGRP免疫反应神经纤维的超微结构和免疫反应物的定位。NPY和VIP免疫反应物位于小颗粒羹泡和线粒体外膜,部分嗜铬细胞呈NPY免疫反应阳性。SP和CGRP免疫反应物主要定位于大颗粒囊泡内。SP和CGRP免疫反应轴突与嗜铬细胞形成对称性或非对称性的轴体突轴。测量了这4种肽能神经末梢的直径,从而推测其来源,并讨论了该4种神经肽对人肾上腺的作用。 相似文献
227.
228.
229.
Effects of Rain‐shelter Cultivation on the Temporal Dynamics of Grape Downy Mildew Epidemics
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Shuyi Yu Changyuan Liu Chunhao Liang Chaoqun Zang Li Liu Hui Wang Tianshu Guan 《Journal of Phytopathology》2017,165(5):331-341
Grape downy mildew (GDM), which is caused by Plasmopara viticola (Berk et Curt.) Burl. & de Toni, is the most destructive grapevine disease in the world. In this study, we chose three cultivars that differ in their resistance to GDM and compared the effects of rain‐shelter cultivation and open‐field cultivation methods on GDM epidemics (2012–2015). The temporal dynamics of GDM were examined over a 4‐year period the results indicated that the disease index fit an S‐shaped curve, and further analysis revealed that a logistic model best fit the disease development and derived epidemic periods. Rain‐shelter cultivation significantly delayed the epidemic onset by 30 days, reduced the epidemic phase by 4 days, and decreased the final disease index by 50% as compared to open‐field cultivation. The logistic and decline phases were shortened significantly by 7 and 21 days under rain‐shelter conditions, respectively. Moreover, the rain‐shelter cultivation technique effectively decreased the highest apparent infection rate and standard area under the disease progression curve values associated with reduced disease severity. The above results demonstrate that rain‐shelter cultivation significantly affects temporal dynamics parameters of GDM. Meteorological factors had significant effects on the GDM epidemic in that the apparent infection rate was significantly positively correlated with mean temperature, relative humidity, rainfall, and leaf wetness duration before the first week of the experiment. 相似文献
230.
Modification of the ionizing radiation response in living cells by an scFv against the DNA-dependent protein kinase 总被引:2,自引:0,他引:2
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The non-homologous end joining pathway uses pre-existing proteins to repair DNA double-strand breaks induced by ionizing radiation. Here we describe manipulation of this pathway in living cells using a newly developed tool. We generated a single chain antibody variable fragment (scFv) that binds to the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a key enzyme in the pathway. In contrast to existing pharmacologic inhibitors, the scFv binds a newly defined regulatory site outside the kinase catalytic domain. Although the scFv inhibits kinase activity only modestly, it completely blocks DNA end joining in a cell-free system. Microinjection of the scFv sensitizes human cells to radiation, as measured by a reduction in efficiency of colony formation and induction of apoptosis at an otherwise sublethal dose of 1.5 Gy. The scFv blocks non-homologous end joining in situ at a step subsequent to histone γ-H2AX focus formation but preceding γ-H2AX dephosphorylation. Blockage occurs in cells exposed to as little as 0.1 Gy, indicating that DNA-PKcs is essential for double-strand break repair even at low radiation doses. The ability to modify the radiation response in situ in living cells provides a link between biochemical, genetic and cytologic approaches to the study of double-strand break repair intermediates. 相似文献