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91.
Alexandra M. Birrell Annemarie Hennessy Adrian Gillin John Horvath David Tiller 《Journal of medical primatology》1996,25(4):287-293
Abstract: Baboons are widely used in biomedical research. Although it is widely held that Papio hamadryas breed well in captivity, each established colony has a different reproductive success often hypothesised to be due to husbandry practices. The National Baboon Colony in Australia is a unique colony that houses Papio hamadryas to mimic that structure seen in the wild. In this article; we have analysed their reproductive parameters and neonatal outcomes. The success of the colony husbandry practices was demonstrated by lack of maternal mortality, low foetal morbidity, and known maternal and paternal linage. 相似文献
92.
Natural underlying mtDNA heteroplasmy as a potential source of intra‐person hiPSC variability 下载免费PDF全文
Ester Perales‐Clemente Alexandra N Cook Jared M Evans Samantha Roellinger Frank Secreto Valentina Emmanuele Devin Oglesbee Vamsi K Mootha Michio Hirano Eric A Schon Andre Terzic Timothy J Nelson 《The EMBO journal》2016,35(18):1979-1990
Functional variability among human clones of induced pluripotent stem cells (hiPSCs) remains a limitation in assembling high‐quality biorepositories. Beyond inter‐person variability, the root cause of intra‐person variability remains unknown. Mitochondria guide the required transition from oxidative to glycolytic metabolism in nuclear reprogramming. Moreover, mitochondria have their own genome (mitochondrial DNA [mtDNA]). Herein, we performed mtDNA next‐generation sequencing (NGS) on 84 hiPSC clones derived from a cohort of 19 individuals, including mitochondrial and non‐mitochondrial patients. The analysis of mtDNA variants showed that low levels of potentially pathogenic mutations in the original fibroblasts are revealed through nuclear reprogramming, generating mutant hiPSCs with a detrimental effect in their differentiated progeny. Specifically, hiPSC‐derived cardiomyocytes with expanded mtDNA mutations non‐related with any described human disease, showed impaired mitochondrial respiration, being a potential cause of intra‐person hiPSC variability. We propose mtDNA NGS as a new selection criterion to ensure hiPSC quality for drug discovery and regenerative medicine. 相似文献
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Female social dominance is rare in mammals, but common in lemurs. We investigated social dominance in two Eulemur species; the polygynous crowned lemur (E. coronatus) and the monogamous red‐bellied lemur (E. rubriventer), using four and two social groups, respectively. We collected data on agonistic interactions and two types of affiliative behavior (grooming and maintaining spatial proximity). We used a combination of focal watches of individuals, instantaneous scan‐sampling of groups, and all‐occurrence of some behaviors in groups. We found that overall rates of agonistic interactions were higher in E. coronatus, and they also had more decided intersexual agonistic interactions than E. rubriventer. However, in both species the females won the vast majority of these agonistic interactions. E. coronatus females were groomed more often by males than vice versa, whereas no sex differences in grooming were observed in E. rubriventer. We found that males were responsible for maintaining spatial proximity in E. coronatus whereas in E. rubriventer, females were responsible. In one group of E. coronatus, the male was overweight and dominant to the female and this is the first observation of male dominance in a lemur species typically described as female dominant. We suggest that body weights in captivity be monitored for maintaining normal dominance relationships. Overall, agonistic behaviors were consistent with clear female social dominance in both E. coronatus and E. rubriventer. The affiliative behaviors also provided clear evidence for female dominance E. coronatus, but not for E. rubriventer. Zoo Biol 0: 1–14, 2007. © 2007 Wiley‐Liss, Inc. 相似文献
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Lehnik-Habrink M Newman J Rothe FM Solovyova AS Rodrigues C Herzberg C Commichau FM Lewis RJ Stülke J 《Journal of bacteriology》2011,193(19):5431-5441
The control of mRNA stability is an important component of regulation in bacteria. Processing and degradation of mRNAs are initiated by an endonucleolytic attack, and the cleavage products are processively degraded by exoribonucleases. In many bacteria, these RNases, as well as RNA helicases and other proteins, are organized in a protein complex called the RNA degradosome. In Escherichia coli, the RNA degradosome is assembled around the essential endoribonuclease E. In Bacillus subtilis, the recently discovered essential endoribonuclease RNase Y is involved in the initiation of RNA degradation. Moreover, RNase Y interacts with other RNases, the RNA helicase CshA, and the glycolytic enzymes enolase and phosphofructokinase in a degradosome-like complex. In this work, we have studied the domain organization of RNase Y and the contribution of the domains to protein-protein interactions. We provide evidence for the physical interaction between RNase Y and the degradosome partners in vivo. We present experimental and bioinformatic data which indicate that the RNase Y contains significant regions of intrinsic disorder and discuss the possible functional implications of this finding. The localization of RNase Y in the membrane is essential both for the viability of B. subtilis and for all interactions that involve RNase Y. The results presented in this study provide novel evidence for the idea that RNase Y is the functional equivalent of RNase E, even though the two enzymes do not share any sequence similarity. 相似文献
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Background: Protein kinase Cs are a family of enzymes that transduce the plethora of signals promoting lipid hydrolysis. Here, we show that protein kinase C must first be processed by three distinct phosphorylations before it is competent to respond to second messengers.Results We have identified the positions and functions of the in vivo phosphorylation sites of protein kinase C by mass spectrometry and peptide sequencing of native and phosphatase-treated kinase from the detergent-soluble fraction of cells. Specifically, the threonine at position 500 (T500) on the activation loop, and T641 and S660 on the carboxyl terminus of protein kinase C βII are phosphorylated in vivo. T500 and S660 are selectively dephosphorylated in vitro by protein phosphatase 2A to yield an enzyme that is still capable of lipid-dependent activation, whereas all three residues are dephosphorylated by protein phosphatase 1 to yield an inactive enzyme. Biochemical analysis reveals that protein kinase C autophosphorylates on S660, that autophosphorylation on S660 follows T641 autophosphorylation, that autophosphorylation on S660 is accompanied by the release of protein kinase C into the cytosol, and that T500 is not an autophosphorylation site.Conclusion Structural and biochemical analyses of native and phosphatase-treated protein kinase C indicate that protein kinase C is processed by three phosphorylations. Firstly, trans-phosphorylation on the activation loop (T500) renders it catalytically competent to autophosphorylate. Secondly, a subsequent autophosphorylation on the carboxyl terminus (T641) maintains catalytic competence. Thirdly, a second autophosphorylation on the carboxyl terminus (S660) regulates the enzyme's subcellular localization. The conservation of each of these residues (or an acidic residue) in conventional, novel and atypical protein kinase Cs underscores the essential role for each in regulating the protein kinase C family. 相似文献
99.
Anne Boissière Majoline T. Tchioffo Dipankar Bachar Luc Abate Alexandra Marie Sandrine E. Nsango Hamid R. Shahbazkia Parfait H. Awono-Ambene Elena A. Levashina Richard Christen Isabelle Morlais 《PLoS pathogens》2012,8(5)
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission. 相似文献
100.
Anne-Sophie Riteau Mikael Tassin Guillemette Chambon Claudine Le Vaillant Jocelyne de Laveaucoupet Marie-Pierre Quéré Madeleine Joubert Sophie Prevot Henri-Jean Philippe Alexandra Benachi 《PloS one》2014,9(4)