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Rameshwaram NR Karanam NK Scharf C Völker U Nadimpalli SK 《Glycoconjugate journal》2009,26(2):161-172
A new unique lectin (galactose-specific) purified from the seeds of Dolichos lablab, designated as DLL-II is a heterodimer composed of closely related subunits α and β. These were separated by SDS-PAGE and
isolated by electroelution. By ESI-MS analysis their molecular masses were found to be 30.746 kDa (α) and 28.815 kDa (β) respectively.
Both subunits were glycosylated and displayed similar amino acid composition. Using advanced mass spectrometry in combination
with de novo sequencing and database searches for the peptides derived by enzymatic and chemical cleavage of these subunits, the primary
sequence was deduced. This revealed DLL-II to be made of two polypeptide chains of 281(α) and 263(β) amino acids respectively.
The β subunit differed from the α subunit by the absence of some amino acids at the carboxy terminal end. This structural
difference suggests that possibly, the β subunit is derived from the α subunit by posttranslational proteolytic modification
at the COOH-terminus. Comparison of the DLL-II sequence to other leguminous seed lectins indicates a high degree of structural
conservation.
Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
194.
Sara T. Scharf 《Journal of the history of biology》2009,42(1):73-117
The origins of field guides and other plant identification manuals have been poorly understood until now because little attention
has been paid to 18th century botanical identification guides. Identification manuals came to have the format we continue
to use today when botanical instructors in post-Revolutionary France combined identification keys (step-wise analyses focusing
on distinctions between plants) with the “natural method” (clustering of similar plants, allowing for identification by gestalt)
and alphabetical indexes. Botanical works featuring multiple but linked techniques to enable plant identification became very
popular in France by the first decade of the 19th century. British botanists, however, continued to use Linnaeus’s sexual
system almost exclusively for another two decades. Their reluctance to use other methods or systems of classification can
be attributed to a culture suspicious of innovation, anti-French sentiment and the association of all things Linnaean with
English national pride, fostered in particular by the President of the Linnean Society of London, Sir James Edward Smith.
The British aversion to using multiple plant identification technologies in one text also helps explain why it took so long
for English botanists to adopt the natural method, even after several Englishmen had tried to introduce it to their country.
Historians of ornithology emphasize that the popularity of ornithological guides in the 19th and 20th centuries stems from
their illustrations, illustrations made possible by printing technologies that improved illustration quality and reduced costs.
Though illustrations are the most obvious features of late 19th century and 20th century guides, the organizational principles
that make them functional as identification devices come from techniques developed in botanical works in the 18th century. 相似文献
195.
Chen L Zhang J Hu X Philipson KD Scharf SM 《Journal of applied physiology (Bethesda, Md. : 1985)》2010,109(6):1675-1685
Chronic intermittent hypoxia (CIH) and cardiovascular dysfunction occur in patients with obstructive sleep apnea. We hypothesized that the Na(+)/Ca(2+) exchanger-1 (NCX1) mediates, at least partially, left ventricular (LV) dysfunction in CIH. Four groups of mice (N = 15-17 per group), either cardiac-specific NCX1 knockouts (KO) or wild types (WT), were exposed to either CIH or normoxia [i.e., handled controls (HC)] 10 h/day for 8 wk. As expected, myocardial expression of NCX1 was greater in WT than in KO animals, both in HC and CIH-exposed groups. In both CIH groups (WT or KO), but not the HC groups, blood pressure increased by 10% at week 1 over their baseline and remained elevated for all 8 wk, with no differences between WT and KO. LV dilation (increased diastolic and systolic dimension) and hypertrophy (increased left heart weight), along with LV dysfunction (greater end-diastolic pressure and lower ejection fraction), were observed in the WT animals compared with the KO following CIH exposure. Compared with HC, CIH exposure was associated with apoptosis (terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling and caspase-3) in WT, but not KO, mice. We conclude that myocardial NCX1 does not mediate changes in blood pressure, but is one of the mediators for LV global dysfunction and cardiomyocyte injury in CIH. 相似文献
196.
Stefanie Scharf Kremena Vardarova Friederike Lang Bernd Schmeck Bastian Opitz Antje Flieger Klaus Heuner Stefan Hippenstiel Norbert Suttorp Philippe D N'Guessan 《Respiratory research》2010,11(1):93
Background
Legionella pneumophila is an important causative agent of severe pneumonia in humans. Human alveolar epithelium and macrophages are effective barriers for inhaled microorganisms and actively participate in the initiation of innate host defense. The beta defensin-3 (hBD-3), an antimicrobial peptide is an important component of the innate immune response of the human lung. Therefore we hypothesize that hBD-3 might be important for immune defense towards L. pneumophila.Methods
We investigated the effects of L. pneumophila and different TLR agonists on pulmonary cells in regard to hBD-3 expression by ELISA. Furthermore, siRNA-mediated inhibition of TLRs as well as chemical inhibition of potential downstream signaling molecules was used for functional analysis.Results
L. pneumophila induced release of hBD-3 in pulmonary epithelium and alveolar macrophages. A similar response was observed when epithelial cells were treated with different TLR agonists. Inhibition of TLR2, TLR5, and TLR9 expression led to a decreased hBD-3 expression. Furthermore expression of hBD-3 was mediated through a JNK dependent activation of AP-1 (c-Jun) but appeared to be independent of NF-κB. Additionally, we demonstrate that hBD-3 elicited a strong antimicrobial effect on L. pneumophila replication.Conclusions
Taken together, human pulmonary cells produce hBD-3 upon L. pneumophila infection via a TLR-JNK-AP-1-dependent pathway which may contribute to an efficient innate immune defense. 相似文献197.
Background
Strict regulation of caste differentiation, at the molecular level, is thought to be important to maintain social structure in insect societies. Previously, a number of extrinsic and intrinsic factors have been shown to influence caste composition in termite colonies. One important factor is the influence of nestmates; in particular, soldier termites are known to inhibit hormone-dependent worker-to-soldier differentiation. However, soldier influences on nestmates at the molecular level are virtually unknown. Here, to test the hypothesis that soldiers can influence nestmate gene expression, we investigated the impact of four treatments on whole-body gene expression in totipotent Reticulitermes flavipes workers: (i) juvenile hormone III (JHIII; a morphogenetic hormone), (ii) soldier head extracts (SHE), (iii) JHIII+SHE, and (iv) live soldiers. 相似文献198.
Kleinbongard P Dejam A Lauer T Jax T Kerber S Gharini P Balzer J Zotz RB Scharf RE Willers R Schechter AN Feelisch M Kelm M 《Free radical biology & medicine》2006,40(2):295-302
A reduced nitric oxide availability is a hallmark of endothelial dysfunction occurring early in atherosclerosis. Recently, we have shown that plasma nitrite mirrors acute changes in endothelial nitric oxide synthase activity in various mammals, including humans. Here, we examined the hypothesis that plasma nitrite levels are reduced in humans with endothelial dysfunction and the decrease is correlated with increasing numbers of cardiovascular risk factors (RF). Plasma nitrite concentrations were quantified by flow-injection analysis. The coefficient of variation for repeated measurements of plasma nitrite was <8%, and heart rate and blood pressure at the time of blood sampling had no significant effect on nitrite values measured (n=10). Baseline levels of plasma nitrite followed a normal distribution in each group studied and decreased progressively with increasing numbers of cardiovascular risk factors (n=351, p<0.001): 351+/-13 (0 RF), 261+/-10 (1 RF), 253+/-11 (2 RF), 222+/-18 (3 RF), and 171+/-29 nmol/L (4 RF). Intima media thickness (IMT) and flow-mediated dilation (FMD) were determined via ultrasound. Plasma nitrite and FMD levels were lower, whereas IMT was greater in individuals with endothelial dysfunction (n=12) compared to healthy volunteers (n=12). Nitrite correlated significantly with FMD (r=0.56, p<0.001) and inversely with IMT (r= -0.49, p<0.01). Plasma nitrite levels are reliably measurable in humans, indicate endothelial dysfunction, and correlate with cardiovascular risk factors. Future studies are necessary to identify the prognostic relevance of plasma nitrite determination in patients suffering from cardiovascular disease. 相似文献
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