全文获取类型
收费全文 | 169篇 |
免费 | 19篇 |
出版年
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 15篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 14篇 |
2009年 | 8篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2001年 | 3篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1958年 | 5篇 |
1957年 | 1篇 |
1956年 | 2篇 |
1955年 | 2篇 |
1954年 | 2篇 |
1953年 | 4篇 |
1952年 | 4篇 |
1951年 | 2篇 |
1949年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 15 毫秒
101.
Hazim F. EL Sharif Flavio Giosia Subrayal M. Reddy 《Journal of molecular recognition : JMR》2022,35(1):e2942
In conjunction with polyacrylamide gel electrophoresis (PAGE), molecular imprinting methods have been applied to produce a multilayer mini-slab in order to evaluate how selectively and specifically a hydrogel-based molecularly imprinted polymer (MIP) binds bovine haemoglobin (BHb, ~64.5 kDa). A three-layer mini-slab comprising an upper and lower layer and a MIP, or a non-imprinted control polymer dispersion middle layer has been investigated. The discriminating MIP layer, also based on polyacrylamide, was able to specifically bind BHb molecules in preference to a protein similar in molecular weight such as bovine serum albumin (BSA, ~66 kDa). Protein staining allowed us to visualise the protein retention strength of the MIP layer under the influence of an electric field. This method could be applied to other proteins with implications in effective protein capture, disease diagnostics, and protein analysis. 相似文献
102.
A simple, sensitive and rapid spectrofluorimetric method was developed for the determination of esomeprazole (EMZ) and pantoprazole (PRZ) in their pharmaceutical formulations and human plasma. The proposed method is based on the fluorescence spectral behavior of EMZ in methanol in the presence of 0.1 m NaOH containing 0.5% methyl cellulose (MC) at 306/345 nm. The fluorescence intensity of EMZ was enhanced about 1.3‐fold and good linearity in the range 0.4–4.0 µg/mL with a lower detection limit of 0.04 µg/mL and lower quantification limit of 0.14 µg/mL. For PRZ, its methanolic solution exhibited marked native fluorescence at 290/325 nm after enhancement (about 2.1‐ or 1.4‐fold) using either 0.025% sodium dodecyl sulfate (SDS) or 0.05% MC in the presence of 0.2 m borate buffer of pH 9.5. The fluorescence–concentration plots of PRZ were rectilinear over the ranges 0.2–2.0 and 0.3–3.0 µg/mL with lower detection limits of 0.02 and 0.03 µg/mL and lower quantification limits of 0.07 and 0.09 µg/mL using sodium dodecyl sulfate and MC, respectively. The method was successfully applied to the analysis of EMZ and PRZ in their commercial dosage forms and the results were in good agreement with those obtained with the comparison method. Furthermore, in a preliminary investigation, the proposed method was extended to the in vitro determination of the two drugs in spiked human plasma and the results were satisfactory. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
103.
Ola Spjuth Tobias Helmus Egon L Willighagen Stefan Kuhn Martin Eklund Johannes Wagener Peter Murray-Rust Christoph Steinbeck Jarl ES Wikberg 《BMC bioinformatics》2007,8(1):59
Background
There is a need for software applications that provide users with a complete and extensible toolkit for chemo- and bioinformatics accessible from a single workbench. Commercial packages are expensive and closed source, hence they do not allow end users to modify algorithms and add custom functionality. Existing open source projects are more focused on providing a framework for integrating existing, separately installed bioinformatics packages, rather than providing user-friendly interfaces. No open source chemoinformatics workbench has previously been published, and no sucessful attempts have been made to integrate chemo- and bioinformatics into a single framework. 相似文献104.
105.
Erratum: Wunderlich RE, Simons EL, Jungers WL. 1996. New Pedal Remains of Megaladapis and Their Functional Significance. Am J Phys Anthropol 100:115–139. 相似文献
106.
Use of climatic data and satellite imagery to model the abundance of Culicoides imicola, the vector of African horse sickness virus, in Morocco 总被引:1,自引:0,他引:1
African horse sickness (AHS) is a vector-borne, infectious disease of equids caused by African horse sickness virus (AHSV) . The only proven field vector of the virus is the biting midge Culicoides imicola. Following a recent epizootic (1989–91) of AHS in Morocco, light traps and automatic weather stations were operated for 2 years at twenty-two sites distributed over much of the country. The annually-averaged mean daily trap catch of C. imicola at these sites was negatively correlated with wind speed, and positively correlated with the average and mean annual minimum NDVI (Normalized Difference Vegetation Index, a remotely sensed measure of vegetation activity). There were no significant correlations between the mean daily trap catch and air temperature, soil temperature, relative humidity, saturation deficit, rainfall, altitude or the mean annual maximum or range of NDVI. The best two-variable model, which combined WindspeedMnAvMn (the average daily minimum wind speed of the least windy month) and NDVImin (the average annual minimum NDVI) as predictors, explained over 50% of the variance in the annually-averaged mean daily trap catch of C. imicola. There was a significant, positive correlation between minimum wind speed at night and the daily mortality rate of adult female C. imicola and it is suggested that the relationship between wind speed and the abundance of C. imicola arises from effects on adult mortality or dispersal. Considering several climatic variables, in North Africa NDVImin was most significantly correlated with total annual rainfall. It is suggested that the relationship between NDVImin and the abundance of C. imicola arises from the impact of soil moisture on both. It is proposed that areas of Morocco with higher levels of soil moisture in late summer or autumn provide more, larger and/or more enduring breeding sites for C. imicola, as well as supporting more photosynthetically active vegetation and hence having higher NDVI. 相似文献
107.
Tirsa L. E. van Westering Henrik J. Johansson Britt Hanson Anna M. L. Coenen-Stass Yulia Lomonosova Jun Tanihata Norio Motohashi Toshifumi Yokota Shin'ichi Takeda Janne Lehti Matthew J. A. Wood Samir EL Andaloussi Yoshitsugu Aoki Thomas C. Roberts 《Molecular & cellular proteomics : MCP》2020,19(12):2047-2068
- Download : Download high-res image (116KB)
- Download : Download full-size image
- •Proteomics analysis was performed in two murine models of Duchenne muscular dystrophy (mdx and mdx52) at three ages (8, 16 and 80 weeks) and compared with wild-type controls.
- •High-resolution isoelectric focusing liquid chromatography-tandem mass spectrometry enabled the quantification of 4974 proteins in all samples.
- •This study has revealed protein signatures of dystrophin deficiency and the progression of dystrophic pathology.
- •In contrast, the proteomes of the mdx and mdx52 mice were highly similar.
- •Pathway analysis revealed crosstalk between inflammatory, metabolic and muscle growth processes in dystrophic muscle.
108.
Genetic footprints of late Quaternary climate change in the diversity of Patagonian‐Fueguian rodents
Species are impacted by climate change at both ecological and evolutionary time scales. Studies in northern continents have provided abundant evidence of dramatic shifts in distributions of species subsequent to the last glacial maximum (LGM), particularly at high latitudes. However, little is known about the history of southern continents, especially at high latitudes. South America is the only continent, other than Antarctica, that extends beyond 40 °S. Genetic studies of a few Patagonian species have provided seemingly conflicting results, indicating either postglacial colonization from restricted glacial refugia or persistence through glacial cycles and in situ differentiation. Using mitochondrial DNA sequences of 14 species of sigmodontine rodents, a major faunal ensemble of Patagonia and Tierra del Fuego, we show that at least nine of these species bear genetic footprints of demographic expansion from single restricted sources. However, timing of demographic expansion precedes the LGM in most of these species. Four species are fragmented phylogeographically within the region. Our results indicate that (i) demographic instability in response to historical climate change has been widespread in the Patagonian‐Fueguian region, and is generally more pronounced at high latitudes in both southern and northern continents; (ii) colonization from lower latitudes is an important component of current Patagonian‐Fueguian diversity; but (iii) in situ differentiation has also contributed to species diversity. 相似文献
109.
Kristina Hanspers Martina Kutmon Susan L. Coort Daniela Digles Lauren J. Dupuis Friederike Ehrhart Finterly Hu Elisson N. Lopes Marvin Martens Nhung Pham Woosub Shin Denise N. Slenter Andra Waagmeester Egon L. Willighagen Laurent A. Winckers Chris T. Evelo Alexander R. Pico 《PLoS computational biology》2021,17(8)
110.
A cyanobacterial bloom prevents fish trophic cascades 总被引:1,自引:0,他引:1
CAROLINE RONDEL ROBERT ARFI DANIEL CORBIN FRÉDÉRIC LE BIHAN EL HADJI NDOUR XAVIER LAZZARO 《Freshwater Biology》2008,53(4):637-651
1. We experimentally compared the impacts of visually feeding zooplanktivorous fish and filter‐feeding omnivorous fish in shallow tropical Dakar Bango reservoir, Senegal. We provoked a cyanobacterial Anabaena bloom under mesotrophic to eutrophic N‐limited conditions in 18 enclosures assigned to six Nile tilapia life‐stage treatments, at typical biomasses: fishless control (C), zooplanktivorous fry (Z), omnivorous juveniles (O), herbivorous fingerlings (H) and two combinations (OZ, OH). 2. All fish grew well, but as prevalent inedible phytoplankton dampened fish effects, community‐level trophic cascades did not occur. Planktivore types acted independently and affected differentially the biomasses of total zooplankton, cyclopoids, nauplii, cladocerans, invertebrate carnivores, large herbivores, colonial cyanobacteria and Chlorophyta. They neither influenced the total biomass of phytoplankton, nor most water chemistry characteristics. Responses were apparently not fish‐biomass related. The bloom collapsed synchronously in all enclosures, coinciding with enrichment ending, with a return to clear water within 12 days. 3. Our results support the hypothesis that excess nutrients and prevalent inedible cyanobacteria inhibit the cascading effects of natural biomass levels of both visually feeding zooplanktivores and filter‐feeding omnivores. In N‐limited meso‐eutrophic shallow tropical lakes with predominantly small herbivorous zooplankton, neither the type nor the biomass of planktivorous fish present seems likely to prevent the transient outburst of cyanobacterial blooms. Such fragile ecosystems may thus not sustain a trophic state suitable for drinking water production, unless human impacts are restricted. The generality of restoration approaches based on ecological engineering should be further explored. 相似文献