全文获取类型
收费全文 | 805篇 |
免费 | 42篇 |
国内免费 | 7篇 |
出版年
2023年 | 6篇 |
2022年 | 26篇 |
2021年 | 25篇 |
2020年 | 20篇 |
2019年 | 34篇 |
2018年 | 44篇 |
2017年 | 23篇 |
2016年 | 33篇 |
2015年 | 41篇 |
2014年 | 61篇 |
2013年 | 66篇 |
2012年 | 71篇 |
2011年 | 68篇 |
2010年 | 30篇 |
2009年 | 26篇 |
2008年 | 31篇 |
2007年 | 22篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 17篇 |
2002年 | 7篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1968年 | 2篇 |
排序方式: 共有854条查询结果,搜索用时 15 毫秒
1.
Elrashdy M. Redwan Vladimir N. Uversky Esmail M. El-Fakharany Hussein Al-Mehdar 《Comptes rendus biologies》2014,337(10):581-595
Lactoferrin (LF) is an 80-kDa globular glycoprotein with high affinity for metal ions, particularly for iron. This protein possesses many biological functions, including the binding and release of iron and serves as one of the important components of the innate immune system, where it acts as a potent inhibitor of several pathogens. LF has efficacious antibacterial and antiviral activities against a wide range of Gram-positive and Gram-negative bacteria and against both naked and enveloped DNA and RNA viruses. In its antiviral pursuit, LF acts predominantly at the acute phase of the viral infection or even at the intracellular stage, as in hepatitis C virus infection. LF inhibits the entry of viral particles into host cells, either by direct attachment to the viral particles or by blocking their cellular receptors. This wide range of activities may be attributed to the capacity of LF to bind iron and its ability to interfere with the cellular receptors of both hosts and pathogenic microbes. 相似文献
2.
A. A. Moaty Sayed M. A. Hussein T. Becker 《Biomechanics and modeling in mechanobiology》2010,9(2):141-151
Lattice Boltzmann models (LBM) are rapidly showing their ability to simulate a lot of fluid dynamics problems that previously
required very complex approaches. This study presents a LBM for simulating diffusion–advection transport of substrate in a
2-D laminar flow. The model considers the substrate influx into a set of active cells placed inside the flow field. A new
innovative method was used to simulate the cells activity using the LBM by means of Michaelis–Menten kinetics. The model is
validated with some numerical benchmark problems and proved highly accurate results. After validation the model was used to
simulate the transport of oxygen substrates that diffuse in water to feed a set of active cartilage cells inside a new designed
bioreactor. 相似文献
3.
Nazar J. Hussein Thomas Mbimba Asaad A. Al-Adlaan Mohammad Y. Ansari Fatima A. Jaber Scott McDermott Takhar Kasumov Fayez F. Safadi 《Journal of cellular biochemistry》2020,121(1):284-298
Trafficking protein particle complex 9 (TRAPPC9) is a major subunit of the TRAPPII complex. TRAPPC9 has been reported to bind nuclear factor κB kinase subunit β (IKKβ) and NF-kB-inducing kinase (NIK) where it plays a role in the canonical and noncanonical of nuclear factor-κB (NF-kB) signaling pathways, receptively. The role of TRAPPC9 in protein trafficking and cytoskeleton organization in osteoclast (OC) has not been studied yet. In this study, we examined the mRNA expression of TRAPPC9 during OC differentiation. Next, we examined the colocalization of TRAPPC9 with cathepsin-K, known to mediate OC resorption suggesting that TRAPPC9 mediates the trafficking pathway within OC. To identify TRAPPC9 protein partners important for OC-mediated cytoskeleton re-organization, we conducted immunoprecipitation of TRAPPC9 in mature OCs followed by mass spectrometry analysis. Our data showed that TRAPPC9 binds various protein partners. One protein with high recovery rate is L-plastin (LPL). LPL localizes at the podosomes and reported to play a crucial role in actin aggregation thereby actin ring formation and OC function. Although the role of LPL in OC-mediated bone resorption has not fully reported in detail. Here, first, we confirmed the binding of LPL to TRAPPC9 and, then, we investigated the potential regulatory role of TRAPPC9 in LPL-mediated OC cytoskeleton reorganization. We assessed the localization of TRAPPC9 and LPL in OC and found that TRAPPC9 is colocalized with LPL at the periphery of OC. Next, we determined the effect of TRAPPC9 overexpression on LPL recruitment to the actin ring using a viral system. Interestingly, our data showed that TRAPPC9 overexpression promotes the recruitment of LPL to the actin ring when compared with control cultures. In addition, we observed that TRAPPC9 overexpression reorganizes actin clusters/aggregates and regulates vinculin recruitment into the OC periphery to initiate podosome formation. 相似文献
4.
Suitability of different mite prey for the development of the predatory mite,Phytoseiulus persimilis
Development of the phytoseiid mitePhytoseiulus persimilis Athias-Henriot was studied when fed on three mite species as prey. The tenuipalpid mite,Brevipalpus pulcher (Canestrini & Fanzago), is an unsuitable prey forP. persimilis as predatory larvae reared on any stages developed to the protonymphal stage only. WhenP. persimilis larvae were reared on the eriophyid mite,Eriophyes dioscoridis Soliman & Abou-Awad, only a few developed to adulthood, but failed to oviposit. On the contrary, predatory larvae fed on the tetranychid mite,Tetranychus urticae Koch, matured in a significantly shorter period and resulting females exhibited a high rate of reproduction. 相似文献
5.
6.
7.
Aly H. Rasmy H. A. Abdel-Rahman M. M. Abdek-Kader H. E. Hussein 《Experimental & applied acarology》1990,10(2):151-155
The effects of attack by the three predaceous mite speciesPhytoseiulus persimilis Athias-Henriot,Phytoseius finitimus Ribaga andAmblyseius gossipi Elbadry on the development, reproduction and mortality of the two-spotted spider miteTetranyschus urticae Koch were evaluated after the prey larvae being exposed to attack by these predators for limited periods. Development of the surviving prey immatures was significantly prolonged; this influence was more distinctive when prey larvae were exposed to the predators for a longer period. The number of prey adults which died early was positively correlated with the length of the feeding period allowed to the predators. A substantial reduction in the number of eggs deposited by the prey females was noted, although the oviposition by the prey females was noted, although the oviposition period and adult longivity were not significantly affected. 相似文献
8.
Nielsen J; Peixoto AA; Piccin A; Costa R; Kyriacou CP; Chalmers D 《Molecular biology and evolution》1994,11(6):839-853
The region of the clock gene period (per) that encodes a repetitive tract
of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran
species both within and outside the Drosophilidae. All the non-
Drosophilidae sequences in this region are short and present a remarkably
stable picture compared to the Drosophilidae, in which the region is much
larger and extremely variable, both in size and composition. The
accelerated evolution in the repetitive region of the Drosophilidae appears
to be mainly due to an expansion of two ancestral repeats, one encoding a
Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and
asparagine or threonine. In some drosophilids the expansion involves a
duplication of the pentapeptide sequence, but in Drosophila pseudoobscura
both the dipeptide and the pentapeptide repeats are present in larger
numbers. In the nondrosophilids, however, the pentapeptide sequence is
represented by one copy and the dipeptide by two copies. These observations
fulfill some of the predictions of recent theoretical models that have
simulated the evolution of repetitive sequences.
相似文献
9.
Dr. Sherif M. H. Sanad Alshimaa A. M. Abdelsalam Aya A. Gamal Eldin Esraa H. Abdelfattah Fatma R. M. Hussein Nada G. Mohammed Nariman A. S. Taha Prof. Dr. Ahmed E. M. Mekky 《化学与生物多样性》2023,20(6):e202300546
An efficient protocol was adopted to efficiently prepare three new series of bis(pyrazolo[1,5-a]pyrimidines) linked to different spacers. The new bis(pyrazolo[1,5-a]pyrimidines) were prepared in 80–90 % yields by reacting the respective bis(enaminones) and 4-(4-substituted benzyl)-1H-pyrazole-3,5-diamines in pyridine at reflux temperature for 5–7 h. The new products showed a wide spectrum of antibacterial activity against six different bacterial strains. In general, propane- and butane-linked bis(pyrazolo[1,5-a]pyrimidines), which are attached to 3-(4-methyl- or 4-methoxybenzyl) units, had the best antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values up to 2.5 and 5.1 μM, respectively. Additionally, the previous products demonstrated promising MurB inhibitory activity with IC50 values up to 7.2 μM. 相似文献
10.
Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene 总被引:8,自引:1,他引:7
We have analyzed the conserved regions of the gene coding for the
circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria
parasite. The closest evolutionary relative of P. falciparum, the agent of
malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is
consistent with the hypothesis that P. falciparum is an ancient human
parasite, associated with humans since the divergence of the hominids from
their closest hominoid relatives. Three other human Plasmodium species are
each genetically indistinguishable from species parasitic to nonhuman
primates; that is, for the DNA sequences included in our analysis, the
differences between species are not greater than the differences between
strains of the human species. The human P. malariae is indistinguishable
from P. brasilianum, and P. vivax is indistinguishable from P. simium; P.
brasilianum and P. simium are parasitic to New World monkeys. The human P.
vivax-like is indistinguishable from P. simiovale, a parasite of Old World
macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are
evolutionarily recent human parasites, the first two at least acquired only
within the last several thousand years, and perhaps within the last few
hundred years, after the expansion of human populations in South America
following the European colonizations. We estimate the rate of evolution of
the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year.
The divergence between the P. falciparum and P. reichenowi lineages is
accordingly dated 8.9 Myr ago. The divergence between the three lineages
leading to the human parasites is very ancient, about 100 Myr old between
P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between
P. falciparum and the other two.
相似文献