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71.
72.
Human T-Cell Leukemia Virus Type 1 Tax Induction of NF-κB Involves Activation of the IκB Kinase α (IKKα) and IKKβ Cellular Kinases 下载免费PDF全文
73.
Seven Hox cluster-related genes (Dthox-A to -G) have been isolated from the freshwater triclad Dugesia (G.) tigrina, their
sequence compared to other Hox genes and their expression in intact and regenerating organisms analyzed by whole mount in
situ hybridization. Sequence comparison analyses show high similarities of D. tigrina Hox genes to anterior and medial groups
of coelomate Hox genes. Expression analyses show very early, synchronous, and overlapping expression of Dthox -A, -E, -G and
-F in anterior, posterior and lateral regenerative tissues. At one hour of regeneration all Dthox genes studied showed a neat,
clear expression at the wound boundary. Later, as the blastema grows, the expression area expands to more proximal regions
covering the blastema and the distal postblastema regions. Blastemas formed by intercalary regeneration also show a synchronous
expression of the same Hox genes though the onset of activation is much delayed. The finding that the same set of Hox genes
is synchronously activated in anterior, posterior, intercalary and lateral regeneration is in sharp contrast to its well established
role in specifying antero-posterior pattern during embryonic development. The implications of these results as regards ancestral
versus co-opted roles of Hox genes in development and regeneration are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
74.
Bernard Y. Amegadzie Charles R. Hanning Megan M. McLaughlin Miriam Burman Lenora B. Cieslinski George P. Livi Theodore J. Torphy 《Cell biology international》1995,19(6):477-484
Recombinant baculoviruses were constructed to express cDNAs encoding two distinct subtypes of human cAMP-specific phosphodiesterase (hPDE4A and hPDE4B). Infection of Spodoptera frugiperda insect cells with the appropriate recombinant baculoviruses resulted in high level production of biologically-active protein as measured by enzymatic activity and immunoblotting using subtype-specific anti-hPDE4 antisera. Both recombinant proteins showed catalytic activity with a low Km (~ 3 μM) for cAMP (with no cGMP hydrolyzing activity) and were inhibited by R-rolipram with apparent Kis of 0.38 and 0.25 μM, respectively. The recombinant enzymes also contained saturable, stereoselective and high-affinity rolipram-binding sites (Kd ~ 2 nM). Thus, insect cell-derived hPDE4s possess kinetic properties analogous to native enzymes as well as to recombinant enzymes produced in yeast. 相似文献
75.
According to the ultrastructural characteristic observation of the developing male germ cells, spermatogenesis of the crustacean
shrimp, Fenneropenaeus chinensis, is classified into spermatogonia, primary spermatocytes, secondary spermatocyte, four stages of spermatids, and mature sperm.
The basic protein transition during its spermatogenesis is studied by transmission electron microscopy of ammoniacal silver
reaction and immunoelectron microscopical distribution of acetylated histone H4. The results show that basic protein synthesized
in cytoplasm of spermatogonia is transferred into the nucleus with deposition on new duplicated DNA. In the spermatocyte stage,
some nuclear basic protein combined with RNP is transferred into the cytoplasm and is involved in forming the cytoplasmic
vesicle clumps. In the early spermatid, most of the basic protein synthesized in the new spermatid cytoplasm is transferred
into the nucleus, and the chromatin condensed gradually, and the rest is shifted into the pre-acrosomal vacuole. In the middle
spermatid, the nuclear basic protein linked with DNA is acetylated and transferred into the proacrosomal vacuole and assembled
into the acrosomal blastema. At the late spermatid, almost all of the basic protein in the nucleus has been removed into the
acrosome. During the stage from late spermatid to mature sperm, some de novo basic proteins synthesized in the cytoplasm belt
transfer into the nucleus without a membrane and almost all deposit in the periphery to form a supercoating. The remnant histone
H4 accompanied by chromatin fibers is acetylated in the center of the nucleus, leading to relaxed DNA and activated genes
making the nucleus non-condensed. 相似文献
76.
77.
Macrolide use in the previous years is associated with failure to eradicate Helicobacter pylori with clarithromycin‐containing regimens 下载免费PDF全文
Pablo Muñoz‐Gómez Junior Alexander Jordán‐Castro María Abanades‐Tercero José Javier Blanco‐González Eva María Andrés Esteban Julio Valle‐Muñoz 《Helicobacter》2018,23(1)
Background
There is some evidence that prior use of macrolide antibiotics is a useful predictor of the likelihood of standard triple therapy failure in Helicobacter pylori eradication. In this study, we have evaluated whether previous intake of macrolides correlates with failure to eradicate H. pylori using two different first‐line clarithromycin‐containing regimens.Materials and Methods
Retrospective study of 212 patients with H. pylori infection treated with one of two first‐line clarithromycin‐containing regimens: 108 patients treated with triple therapy for 10 days and 104 patients treated with concomitant therapy for 10 days. The intake of macrolides (clarithromycin, azithromycin, and other macrolides) prior to the eradication therapy was obtained from the electronic medical record, which contains information regarding all the medication prescribed to the patients since the year 2004.Results
One hundred of 212 patients (47.2%) had received at least one treatment with macrolides during the years prior to the eradication therapy. H. pylori eradication rates were significantly lower in patients with previous use compared to patients without previous use of macrolides, both with triple therapy (60.8% vs 92.9%; P < .0001) and with concomitant therapy (85.7% vs 98.2%; P = .024).Conclusions
Previous use of macrolides correlates with a low H. pylori eradication rate with triple and concomitant clarithromycin‐containing regimens. In addition, our study shows that in patients without previous use of macrolides, triple therapy achieves per‐protocol eradication rates over 90%. 相似文献78.
79.
Hemizygosity at the NCF1 gene in patients with Williams-Beuren syndrome decreases their risk of hypertension 下载免费PDF全文
Del Campo M Antonell A Magano LF Muñoz FJ Flores R Bayés M Pérez Jurado LA 《American journal of human genetics》2006,78(4):533-542
Williams-Beuren syndrome (WBS), caused by a heterozygous deletion at 7q11.23, represents a model for studying hypertension, the leading risk factor for mortality worldwide, in a genetically determined disorder. Haploinsufficiency at the elastin gene is known to lead to the vascular stenoses in WBS and is also thought to predispose to hypertension, present in approximately 50% of patients. Detailed clinical and molecular characterization of 96 patients with WBS was performed to explore clinical-molecular correlations. Deletion breakpoints were precisely defined and were found to result in variability at two genes, NCF1 and GTF2IRD2. Hypertension was significantly less prevalent in patients with WBS who had the deletion that included NCF1 (P=.02), a gene coding for the p47(phox) subunit of the NADPH oxidase. Decreased p47(phox) protein levels, decreased superoxide anion production, and lower protein nitrotyrosination were all observed in cell lines from patients hemizygous at NCF1. Our results indicate that the loss of a functional copy of NCF1 protects a proportion of patients with WBS against hypertension, likely through a lifelong reduced angiotensin II-mediated oxidative stress. Therefore, antioxidant therapy that reduces NADPH oxidase activity might have a potential benefit in identifiable patients with WBS in whom serious complications related to hypertension have been reported, as well as in forms of essential hypertension mediated by a similar pathogenic mechanism. 相似文献