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101.
Neelakshi Sarkar Ananya Pal Dipanwita Das Debraj Saha Avik Biswas Bhaswati Bandopadhayay Mandira Chakraborti Mrinmoy Ghosh Runu Chakravarty 《PloS one》2015,10(11)
Hepatitis B Virus (HBV) manifests high genetic variability and is classifiable into ten genotypes (A-J). HBV infection can lead to variable clinical outcomes, ranging from self-limiting acute hepatitis to active chronic hepatitis, cirrhosis and hepatocellular carcinoma. The present study characterizes HBV strains circulating among patients with acute (AHB) and chronic HBV infection (CHB). Among a total of 653 HBsAg positive cases, 40 manifested acute infection. After sequencing the surface(S), basal core promoter/pre-core(BCP/PC) and the X gene regions, phylogenetic tree was constructed using MEGA4 by neighbor-joining method. Statistical robustness was established with bootstrap analysis. Nucleotide diversity was determined by Shannon entropy per site using the Entropy program of the Los Alamos National Laboratories. Analyses of acute patients revealed that HBV/D2 is the major circulating sub-genotype and commonly associated with sexual promiscuity and the age group between15-30 years. Comparison of AHB and CHB patients revealed that HBeAg positivity, ALT levels and genotype D were significantly high in AHB, whereas CHB patients were predominantly male, had a high viral load, and were commonly associated with genotype C. The frequencies of mutations in the S, BCP/PC, and X gene were low in AHB as compared to CHB. Drug resistant mutations were not detectable in the polymerase gene of AHB. Average nucleotide diversity in AHB was considerably low as compared to CHB. Further, the highest average ΔH (average difference in entropy between chronic and acute infection) was observed in the BCP/PC region implying that this region was most vulnerable to mutations upon HBV persistence, especially in case of genotype C. Additionally, among all substitutions, the A1762T and G1764A BCP mutations were the strongest indicators of chronicity. In conclusion, the study exhibits a general portrait of HBV strains circulating among acute hepatitis B patients in Eastern India and their intricate differences with chronic patients which should be useful from the clinical point of view. 相似文献
102.
Laura Dyer Pamela Lockyer Yaxu Wu Arnab Saha Chelsea Cyr Martin Moser Xinchun Pi Cam Patterson 《PloS one》2015,10(9)
Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP) signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator) display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT) and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects. 相似文献
103.
Kamala Mitra Abhisek Brata Ghosh Arpita Sarkar Namrata Saha Amit Kumar Dutta 《Biochemical and biophysical research communications》2014
This article reports simple, green and efficient synthesis of γ-Fe2O3 nanoparticles (NPs) (maghemite) through single-source precursor approach for colorimetric estimation of human glucose level. The γ-Fe2O3 NPs, having cubic morphology with an average particle size of 30 nm, exhibited effective peroxidase-like activity through the catalytic oxidation of peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 producing a blue-colored solution. On the basis of this colored-reaction, we have developed a simple, cheap, highly sensitive and selective colorimetric method for estimation of glucose using γ-Fe2O3/TMB/glucose–glucose oxidase (GOx) system in the linear range from 1 to 80 μM with detection limit of 0.21 μM. The proposed glucose sensor displays faster response, good stability, reproducibility and anti-interference ability. Based on this simple reaction process, human blood and urine glucose level can be monitored conveniently. 相似文献
104.
Lactobacillus intermedius NRRL B-3693 produced mannitol, lactic acid, and acetic acid when grown on fructose at 37°C. The optimal pH for mannitol production
from fructose by the heterofermentative lactic acid bacterium (LAB) in pH-controlled fermentation was at pH 5.0. It produced
160.7 ± 1.1 g mannitol in 40 h with a volumetric productivity of 4.0 g l−1 h−1 in a simplified medium containing 250 g fructose, 50 g corn steep liquor (CSL), and 33 mg MnSO4 per liter. However, the mannitol production by the LAB was severely affected by the variability of CSL. The supplementation
of CSL with soy peptone (5 g/l), tryptophan (50 mg/l), tryptophan (50 mg/l) plus tyrosine (50 mg/l), or commercial protease
preparation (2 ml/100 g of CSL) enhanced the performance of the inferior CSL and thus helped to overcome the nutrient limitations. 相似文献
105.
Wetlands such as rice fields and associated canals are congenial habitats for different fishes and provide the foundation of rice‐fish culture. The selection of suitable fish species determines the success for this linkage of aquaculture and agriculture. An assessment of fish assemblages in selected rice fields and associated canals in West Bengal, India documented the candidate species for culture and conservation in rice fields. Indigenous minnow traps made of bamboo were employed in the rice fields and canals for a period of 3 months, to collect and record the fish abundance. A total of 531 fishes representing 19 different species were caught from the rice fields in 30 sampling efforts. From the canals, 13 different fish species totaling 676 fishes were collected in 80 sampling efforts. The fish collected per trap in the rice fields (mean 17.7 ± 1.97 SE) remained significantly different (t = 4.461, df = 112; P < 0.001) from those of the canals (mean 8.05 ± 1.09 SE). Diversity indices ranged between 1.91 and 2.01, with a 53% similarity between the rice fields and canals. Among the fish species collected, Badis badis, Colisa fasciatus and C. lalia exhibited high abundance; the two species Heteropneustes fossilis and Mystus vittatus established as threatened fish categories, showed low abundance. The fish species collected were important as food resources and the ornamental fish trade, and many of them bear potential in regulating mosquitoes in the rice fields. These fish assemblages in the rice fields and associated canals suggest a rice‐fish culture potential for integrating food and health. 相似文献
106.
Unusual fungal agents that exist environmentally as saprophytes can often lead to opportunistic infections. Hyalohyphomycosis
is a group of fungal infections caused by fungi characterized by hyaline septate hyphae and can infect both immunocompetent
as well as immunocompromised patients. Many a times it becomes difficult to distinguish a pathogenic and a contaminant fungus,
because many such agents can assume clinical significance depending on circumstances. Subcutaneous and invasive fungal infection
due to the emerging hyalohyphomycotic fungus, Acremonium, has drawn the attention of clinicians and microbiologists, as a potential pathogen in patients with and without underlying
risk factors. Generally considered to be minimally invasive in the past, genus Acremonium has been responsible for eumycotic mycetomas and focal infections in otherwise healthy individuals. It has also been increasingly
implicated in systemic fungal diseases. The management with different antifungals in various clinical situations has been
very conflicting and hence needs to be carefully evaluated. This overview is an endeavor to consolidate the available clinical
infections due to Acremonium and the recommendations on treatment. 相似文献
107.
Population dynamics of five different species of grasshopper were analyzed for the first time in Darjeeling (Lebong and Happy Valley) of the eastern Himalayan region of India. The study is based on the relationship between monthly samples collected using sweep nets for three years (March, 2005 to February, 2008) in relation to meteorological parameters (monthly average rainfall, monthly mean maximum and minimum temperatures). The population for each of the five species of grasshopper is plotted against the Aridity Ratio (A.R.). For all species, the population increases at lower A.R. values and then decreases exponentially at higher A.R. values. The exponentially decreasing part of the population is modeled using a simple formula. The monthly population of A. crenulata nymphs and adults in Lebong has also been modeled by iterative equations using A.R. and results compared satisfactorily with the sample data. These works show the possibility of forecasting grasshopper populations using a simple model and thereby easing the regulation process. 相似文献
108.
109.
Supratim Basu Aryadeep Roychoudhury Progya Paromita Saha Dibyendu N. Sengupta 《Acta Physiologiae Plantarum》2010,32(3):551-563
Extensive investigation into plant response and adaptation to diverse osmotic stresses like high salt/dehydration/low temperature,
involving a broad spectrum of cellular physiological and biochemical changes, is essential to unravel intrinsic mechanism
to mitigate against such stresses. In our previous communications, we conducted biochemical analyses of indica rice varieties,
subjected to exogenous salt/abscisic acid-mediated oxidative stress. The aim of this study was to compare differential biochemical
responses of the salt-sensitive (IR-29), salt-tolerant (Pokkali) and aromatic (Pusa Basmati or PB) rice varieties during polyethylene
glycol (PEG)-induced dehydration stress. The greater susceptibility of IR-29 and PB, to water scarcity, was reflected by the
higher toxic Na+ and putrescine accumulation, considerable decrease in (reduced/oxidized) glutathione, maximal increment in protease activity
and greater downregulation of nitrate reductase activity. On the other hand, Pokkali appeared to suffer lesser damages as
evidenced from much lower endogenous Na+ but higher K+, Ca2+ and Mg2+ accumulation, registering the highest levels of osmolytes like glycinebetaine and higher polyamines (spermidine and spermine)
accounting to improved relative water content, higher (reduced/oxidized) glutathione, maximal induction of the enzyme phenylalanine
ammonia-lyase and practically unhindered nitrate reductase activity, following PEG treatment. The highest induction of sugars
and proline in IR-29 and PB probably played the osmoprotective/antioxidative functions, enabling to a certain extent to heighten
their lipoxygenase inhibition or H2O2 scavenging potential, more than Pokkali, to ward off oxidative damages and sustain survival under critical dehydrated situations.
Thus, the salt-tolerant Pokkali also showed prominent dehydration-tolerance properties, whereas the aromatic rice PB, almost
identical in their biochemical responses to IR-29, showed greater sensitivity to PEG-mediated water deficit. 相似文献
110.
Summary Competing risks arise naturally in time‐to‐event studies. In this article, we propose time‐dependent accuracy measures for a marker when we have censored survival times and competing risks. Time‐dependent versions of sensitivity or true positive (TP) fraction naturally correspond to consideration of either cumulative (or prevalent) cases that accrue over a fixed time period, or alternatively to incident cases that are observed among event‐free subjects at any select time. Time‐dependent (dynamic) specificity (1–false positive (FP)) can be based on the marker distribution among event‐free subjects. We extend these definitions to incorporate cause of failure for competing risks outcomes. The proposed estimation for cause‐specific cumulative TP/dynamic FP is based on the nearest neighbor estimation of bivariate distribution function of the marker and the event time. On the other hand, incident TP/dynamic FP can be estimated using a possibly nonproportional hazards Cox model for the cause‐specific hazards and riskset reweighting of the marker distribution. The proposed methods extend the time‐dependent predictive accuracy measures of Heagerty, Lumley, and Pepe (2000, Biometrics 56, 337–344) and Heagerty and Zheng (2005, Biometrics 61, 92–105). 相似文献