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761.
Mikhail Abramov Marleen Renders Piet Herdewijn 《Nucleosides, nucleotides & nucleic acids》2013,32(11-12):1042-1050
The 2′-N-formamide derivatives of adenosine, cytidine, and 9-β-d-arabinofuranosyladenine were synthesized and tested (as triphosphate) for their substrate capacities for the HCV NS5B polymerase. 相似文献
762.
Viruses of the family Polyomaviridae infect a wide variety of avian and mammalian hosts with a broad spectrum of outcomes including asymptomatic infection, acute systemic disease, and tumor induction. In this study a novel polyomavirus, the African elephant polyomavirus 1 (AelPyV-1) found in a protruding hyperplastic fibrous lesion on the trunk of an African elephant (Loxodonta africana) was characterized. The AelPyV-1 genome is 5722 bp in size and is one of the largest polyomaviruses characterized to date. Analysis of the AelPyV-1 genome reveals five putative open-reading frames coding for the classic small and large T antigens in the early region, and the VP1, VP2 and VP3 capsid proteins in the late region. In the area preceding the VP2 start codon three putative open-reading frames, possibly coding for an agnoprotein, could be localized. A regulatory, non-coding region separates the 2 coding regions. Unique for polyomaviruses is the presence of a second 854 bp long non-coding region between the end of the early region and the end of the late region. Based on maximum likelihood phylogenetic analyses of the large T antigen of the AelPyV-1 and 61 other polyomavirus sequences, AelPyV-1 clusters within a heterogeneous group of polyomaviruses that have been isolated from bats, new world primates and rodents. 相似文献
763.
Joop P. W. van den Bergh Marian E. Bouts Eveline van der Veer Robert Y. van der Velde Marcel J. W. Janssen Piet P. Geusens Bjorn Winkens Nico J. J. Oldenhof Tineke A. C. M. van Geel 《PloS one》2013,8(10)
Introduction
An increasing number of generic alendronate formulations have become available. Although expected to have the same tolerability and efficacy, head-to head comparison of generic and brand alendronate was never performed. Therefore, we compared the tolerability and efficacy of generic and brand alendronate.Methods
In a randomized double-blinded single centre cross-over study in 37 postmenopausal women (mean age 65.4±6.4 years) with osteoporosis were treated with generic and branded alendronate during 24 (2x12) weeks. Tolerance was evaluated by the Gastro intestinal Symptom Rating Scale (GSRS) and self-reported side effects. Efficacy was assessed by serum bone turnover markers, carboxy terminal telopeptide (CTX) and procollagen type I N-terminal propeptide (PINP). No wash out period was allowed (ethical reasons). Because of possible carry over effect only data of the first 12 weeks were analyzed using linear mixed models.Results
There were no significant differences in overall tolerance (GSRS) between treatment groups. However, for subscale abdominal pain, patients using generic had a significantly higher mean GSRS score at week 4 (estimated mean difference (B): 0.40; 95%CI: 0.05 to 0.74, p = 0.024). The level of bone turnover markers significantly decreased over 12 weeks of follow-up for generic and branded alendronate (p < 0.001). Mean level of CTX was significantly lower with branded at week 4 (B: 121.3; 95%CI: 52.0 to 190.5), but not at week 12 (B: 53.6; 95%CI:-3.7 to 110.9). No significant differences were found for PINP at week 4 or 12.Conclusions
Bone turnover markers were significantly reduced with branded and generic alendronate. With branded, CTX was significantly lower at 4 weeks. Generic caused significantly higher abdominal pain scores in the first 4 weeks of treatment. Therefore, generic alendronate may not have the same tolerability and efficacy as branded alendronate in the first weeks after starting treatment in patients with a recent fracture.Trial Registration
Dutch Trial Register NTR number 1867 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1867 相似文献764.
Parasites influence host life-history traits and therefore might crucially shape host populations in natural systems. In a
series of laboratory experiments, we studied the impact of an oomycete brood parasite on its Daphnia (waterflea) host. We asked whether Daphnia dump the infected brood and subsequently are able to reproduce again as was occasionally observed in a preliminary study.
No viable offspring developed from infected clutches, but 78% of the infected females produced healthy offspring after releasing
the infected brood while molting. Neither those offsprings’ development success nor their mothers’ reproductive potential
was affected by the brood parasite. However, infected Daphnia had a reduced life-span and suffered an increased susceptibility to another parasite, an unidentified bacterium. Additionally,
we studied the prevalence of this brood parasite and the unidentified bacterium in a natural Daphnia assemblage in a pre-alpine lake, across changing demographic and environmental conditions. The brood parasite epidemic seemed
to be host-density dependent. Our results show that the brood parasite’s impact on the host population is enhanced when combined
with the unidentified bacterium. 相似文献
765.
Staphylococcal complement inhibitor: structure and active sites 总被引:2,自引:0,他引:2
Rooijakkers SH Milder FJ Bardoel BW Ruyken M van Strijp JA Gros P 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(5):2989-2998
The pathogenic bacterium Staphylococcus aureus counteracts the host immune defense by excretion of the 85 residue staphylococcal complement inhibitor (SCIN). SCIN inhibits the central complement convertases; thereby, it reduces phagocytosis following opsonization and efficiently blocks all downstream effector functions. In this study, we present the crystal structure of SCIN at 1.8 A resolution and the identification of its active site. Functional characterization of structure based chimeric proteins, consisting of SCIN and the structurally but nonfunctional homologue open reading frame-D, indicate an 18-residue segment (Leu-31-Gly-48) crucial for SCIN activity. In all complement activation pathways, chimeras lacking these SCIN residues completely fail to inhibit production of the potent mediator of inflammation C5a. Inhibition of alternative pathway-mediated opsonization (C3b deposition) and formation of the lytic membrane attack complex (C5b-9 deposition) are strongly reduced for these chimeras as well. For inhibition of the classical/lectin pathway-mediated C3b and C5b-9 deposition, the same residues are critical although additional sites are involved. These chimeras also display reduced capacity to stabilize the C3 convertases of both the alternative and the classical/lectin pathway indicating the stabilizing effect is pivotal for the complement inhibitory activity of SCIN. Because SCIN specifically and efficiently inhibits complement, it has a high potential in anti-inflammatory therapy. Our data are a first step toward the development of a second generation molecule suitable for such therapeutic complement intervention. 相似文献
766.
Wieczorek D Ludwig M Boehringer S Jongbloet PH Gillessen-Kaesbach G Horsthemke B 《Human genetics》2007,121(3-4):369-376
A great number of case reports on concordant and discordant twins with oculo-auriculo-vertebral spectrum (OAVS) suggest that
there might be an association between reproductive abnormalities, twinning and OAVS. The etiology of OAVS is unknown, but
may involve epigenetic dysregulation of the oocyte or early embryo. We collected data on fertility and pregnancy outcome of
72 parents of patients with sporadic OAVS. We also evaluated prospective follow-up data on 3.372 fetuses and children conceived
by intracytoplasmatic sperm injection (ICSI). Parental age, duration of menstrual cycle and the incidence of spontaneous abortion
was not different when compared to the German population. However, there is an excess of parents who have used assisted reproductive
techniques (ART; retrospective P = 0.038, prospective P = 0.023) and an excess of twins among naturally conceived patients with OAVS (P = 0.0025). An excess of ART conceptions and monozygotic twinning in OAVS is compatible with the concept of overripeness ovopathy
as proposed by Jongbloet (Maandschr Kindergeneeskd 36:352–367, 1968). 相似文献
767.
768.
Bhagirath Choudhary Godelieve Gheysen Jeroen Buysse Piet van der Meer Sylvia Burssens 《Plant biotechnology journal》2014,12(2):135-146
The introduction of semi‐dwarfing, high‐yielding and nutrients‐responsive crop varieties in the 1960s and 1970s alleviated the suffering of low crop yield, food shortages and epidemics of famine in India and other parts of the Asian continent. Two semi‐dwarfing genes, Rht in wheat and Sd‐1 in rice heralded the green revolution for which Dr. Norman Borlaug was awarded the Nobel Peace Prize in 1970. In contrast, the revolutionary new genetics of crop improvement shamble over formidable obstacles of regulatory delays, political interferences and public misconceptions. India benefited immensely from the green revolution and is now grappling to deal with the nuances of GM crops. The development of GM mustard discontinued prematurely in 2001 and insect‐resistant Bt cotton varieties were successfully approved for commercial cultivation in 2002 in an evolving nature of regulatory system. However, the moratorium on Bt brinjal by MOEF in 2010 meant a considerable detour from an objective, science‐based, rigorous institutional process of regulatory approval to a more subjective, nonscience‐driven, political decision‐making process. This study examines what ails the regulatory system of GM crops in India and the steps that led to the regulatory logjam. Responding to the growing challenges and impediments of existing biosafety regulation, it suggests options that are critical for GM crops to take roots for a multiplier harvest. 相似文献
769.
Philip J. Aston Gianne Derks Balaji M. Agoram Piet H. van der Graaf 《Journal of mathematical biology》2014,68(6):1453-1478
We consider the possibility of free receptor (antigen/cytokine) levels rebounding to higher than the baseline level after one or more applications of an antibody drug using a target-mediated drug disposition model. Using geometry and dynamical systems analysis, we show that rebound will occur if and only if the elimination rate of the drug–receptor product is slower than the elimination rates of the drug and of the receptor. We also analyse the magnitude of rebound through approximations and simulations and demonstrate that it increases if the drug dose increases or if the difference between the elimination rate of the drug–receptor product and the minimum of the elimination rates of the drug and of the receptor increases. 相似文献
770.
Helena Slaets Sofie Nelissen Kris Janssens Pia M. Vidal Evi Lemmens Piet Stinissen Sven Hendrix Niels Hellings 《Molecular neurobiology》2014,50(3):1142-1151
The family of interleukin (IL)-6 like cytokines plays an important role in the neuroinflammatory response to injury by regulating both neural as well as immune responses. Here, we show that expression of the IL-6 family member oncostatin M (OSM) and its receptor is upregulated after spinal cord injury (SCI). To reveal the relevance of increased OSM signaling in the pathophysiology of SCI, OSM was applied locally after spinal cord hemisection in mice. OSM treatment significantly improved locomotor recovery after mild and severe SCI. Improved recovery in OSM-treated mice was associated with a reduced lesion size. OSM significantly diminished astrogliosis and immune cell infiltration. Thus, OSM limits secondary damage after CNS trauma. In vitro viability assays demonstrated that OSM protects primary neurons in culture from cell death, suggesting that the underlying mechanism involves direct neuroprotective effects of OSM. Furthermore, OSM dose-dependently promoted neurite outgrowth in cultured neurons, indicating that the cytokine plays an additional role in CNS repair. Indeed, our in vivo experiments demonstrate that OSM treatment increases plasticity of serotonergic fibers after SCI. Together, our data show that OSM is produced at the lesion site, where it protects the CNS from further damage and promotes recovery. 相似文献