全文获取类型
收费全文 | 74篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
77篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2011年 | 8篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1982年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 15 毫秒
21.
Sequence of a cDNA for mouse thymidylate synthase reveals striking similarity with the prokaryotic enzyme 总被引:11,自引:0,他引:11
Perryman SM; Rossana C; Deng TL; Vanin EF; Johnson LF 《Molecular biology and evolution》1986,3(4):313-321
We report the nucleotide sequence of a cloned cDNA, pMTS-3, that contains a
1-kb insert corresponding to mouse thymidylate synthase (E.C. 2.1.1.45).
The open reading frame of 921 nucleotides from the first AUG to the
termination codon specifies a protein with a molecular mass of 34,962
daltons. The predicted amino acid sequence is 90% identical with that of
the human enzyme. The mouse sequence also has an extremely high degree of
similarity (as much as 55% identity) with prokaryotic thymidylate synthase
sequences, indicating that thymidylate synthase is among the most highly
conserved proteins studied to date. The similarity is especially pronounced
(as much as 80% identity) in the 44-amino-acid region encompassing the
binding site for deoxyuridylic acid. The cDNA sequence also suggests that
mouse thymidylate synthase mRNA lacks a 3' untranslated region, since the
termination codon, UAA, is followed immediately by a poly(A) segment.
相似文献
22.
Connecting viral with cellular interactomes 总被引:1,自引:0,他引:1
23.
C Magnoli SM Chiacchiera R Miazzo G Palacio A Angeletti C Hallak A Dalcero 《Mycotoxin Research》2002,18(1):7-22
Feedstuffs used for poultry nutrition in Argentina were analyzed for fungal flora and natural incidence of mycotoxins. Survey
of 120 samples of poultry feeds, taken from May 1998 to April 1999, showed the presence of 15 genera of filamentous fungi.
The predominant genera wereFusarium spp. andPenicillium ssp., isolated in 67.5 % of the samples, followed byAspergillus spp. (57.5 %). Yeast, were significantly isolated from most of the samples. Species identification was carried down for the
toxigenic genera. Fungal total counts of poultry feeds ranged from 2.0 × 103 to 3.0 × 105 CFU g-1 The fungal total counts during two months of sampling, were slightly over the limit value of 1 × 105 CFU g-1, which ensure the hygienic quality of the feed. Potentially toxicogenic species presented moderate mean colony counts. Many
of the fungi isolated from poultry feeds are mycotoxin producers. Fumonisins had the highest incidence, and were found in
97 % of the analyzed samples followed by aflatoxin B1 (46 %), zearalenone (18 %) and deoxynivalenol (6 %). On the co-occurrence of both carcinogenic mycotoxins, all of the FBs
contaminated feed samples were co-contaminated with AFB1. The results show the relevance of the samples screening for viable fungi propagules and the surveillance of their associated
mycotoxins in poultry feeds. 相似文献
24.
J Yanci C Granados M Otero A Badiola J Olasagasti I Bidaurrazaga-Letona A Iturricastillo SM Gil 《Biology of sport / Institute of Sport》2015,32(1):71-78
The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm) belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball) agility (T-test and pick-up test) strength (handgrip and maximal pass) and endurance (Yo-Yo 10 m recovery test) were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94). The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s) and maximal pass (8.39 ± 1.77 m), players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB. 相似文献
25.
Quantitative analysis of organophosphorus pesticides in freshwater using an optimized firefly luciferase‐based coupled bioluminescent assay 下载免费PDF全文
In this paper, a coupled bioluminescent assay, relying on the coupling of the enzymes acetylcholinesterase, S‐acetyl‐coenzyme A synthetase and firefly luciferase, for the detection and quantitation of organophosphorus pesticides, is presented. Using malathion as a model organophosphorus pesticide, the assay was optimized through statistical experimental design methodology, namely Plackett–Burman and central composite designs. The optimized method requires only 20 μL of sample. The linear range for the assay was 2.5–15 μM of malathion, with limits of detection and quantitation of 1.5 and 5.0 μM, respectively. This simple, fast and robust method allows samples to be analyzed at room temperature and without any pretreatment. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
26.
Claire SM Kwan Rafael P Vázquez-Manrique Sung Ly Kshamata Goyal Howard A Baylis 《BMC physiology》2008,8(1):11
Background
Ultradian rhythms, rhythms with a period of less than 24 hours, are a widespread and fundamental aspect of life. The mechanisms underlying the control of such rhythms remain only partially understood. Defecation in C. elegans is a very tightly controlled rhythmic process. Underlying the defecation motor programme is an oscillator which functions in the intestinal cells of the animal. This mechanism includes periodic calcium release and subsequent intercellular calcium waves which in turn regulate the muscle contractions that make up the defecation motor programme. Here we investigate the role of TRPM cation channels in this process. 相似文献27.
A total of 27 maize-based products destined for human consumption were collected from retail outlets within the city of Glasgow
in the UK and were analysed for the presence of aflatoxins using immunoaftinity column chromatography with fluorescence detection
and for fumonisins by competitive ELISA. Aflatoxins were detected at a trace level below 4 in eight (30%) of the 27 samples
tested, no sample contained aflatoxins at a high level although one sample of sweetcorn did contain aflatoxins at a level
of 5-10 Fumonisins were detected in eight (30%) of the samples at levels from 1 to 8mgkg-1 and a further eight samples contained fumonisin at a level below 1 mgkg-1 but above the detectable level. The highest concentration of fumonisins was found in a sample of fine corn meal at 8-12mgkg-1. 相似文献
28.
In the aquatically mating harbour seal, Phoca vitulina, oestrous females show marked differences in spatial and temporal distribution between geographical areas. This suggests that the males' display behaviour may also vary between areas. We recorded male vocalizations in two areas, the Moray Firth and Orkney, U.K. In the Moray Firth, females haul out on a few intertidal sandbars and travel along predictable routes to forage at sea. In Orkney, female haul out sites are much less influenced by tidal availability and females are much more dispersed. In the Moray Firth, males vocalized only during a short mating season, from 1 July to 12 August. Vocalizations varied significantly with the tide, the peak at high tide clearly coinciding with the period when most females were in the water. In contrast, vocalizations in Orkney were significantly related to both tidal and diel patterns. We suggest that the timing of male vocalizations reflects differences in female availability between sites. In the inner Moray Firth, vocalizations were heard throughout the females' range, whereas vocalizations in Orkney were heard only in two discrete areas. However, at both sites the density of vocalizing males was highest in narrow channels and/or along predictable female travel routes. Therefore, males clearly adapt their temporal and spatial behaviour patterns to variations in female distribution and density. These results suggest that male mating strategies in aquatically mating pinnipeds are more variable than was previously envisaged. Copyright 1999 The Association for the Study of Animal Behaviour. 相似文献
29.
Muhammad Toyabur Rahman SM Sohel Rana Md Salauddin Pukar Maharjan Trilochan Bhatta Jae Yeong Park 《Liver Transplantation》2020,10(12)
The fast growth of smart electronics requires novel solutions to power them sustainably. Portable power sources capable of harvesting biomechanical energy are a promising modern approach to reduce battery dependency. Herein, a novel elastic impact‐based nonresonant hybridized generator (EINR‐HG) is reported to effectively harvest biomechanical energy from diverse human activities outdoors. Through the rational integration of a nonlinear electromagnetic generator with two contact‐mode triboelectric nanogenerators, the proposed EINR‐HG generates hybrid electrical output simultaneously under the same mechanical excitations. By introducing a flux‐concentrator with a nanowire‐nanofiber surface modification, significant improvement in the energy harvesting efficiency of the EINR‐HG is achieved. After optimizing using simulations and vibration tests, the as‐fabricated EINR‐HG delivers an outstanding normalized power density of 3.13 mW cm?3 g?2 across a matching resistance of 1.5 kΩ at 6 Hz under 1 g acceleration. Under human motion testing, the EINR‐HG generates an optimal output power of 131.4 mW with horizontal handshaking. With a customized power management circuit, the EINR‐HG serves as a universal power source that successfully drives commercial smart electronics, including smart bands and smartphones. This work shows the massive potential of biomechanical energy‐driven hybridized generators for powering personal electronics and portable healthcare monitoring devices. 相似文献
30.
Metal concentrations in the gill, muscle and liver tissues of Labeo rosae from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern. 相似文献