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991.

Introduction

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane, a common industrial chemical which has extremely huge production worldwide, is ubiquitous in the environment. Human have high risk of exposing to BPA and the health problems caused by BPA exposure have aroused public concern. However, the biomarkers for BPA exposure are lacking. As a rapidly developing subject, metabolomics has accumulated a large amount of valuable data in various fields. The secondary application of published metabolomics data could be a very promising field for generating novel biomarkers whilst further understanding of toxicity mechanisms.

Objectives

To summarize the published literature on the use of metabolomics as a tool to study BPA exposure and provide a systematic perspectives of current research on biomarkers screening of BPA exposure.

Methods

We conducted a systematic search of MEDLINE (PubMed) up to the end of June 25, 2017 with the key term combinations of ‘metabolomics’, ‘metabonomics’, ‘mass spectrometry’, ‘nuclear magnetic spectroscopy’, ‘metabolic profiling’ and ‘amino acid profile’ combined with ‘BPA exposure’. Additional articles were identified through searching the reference lists from included studies.

Results

This systematic review included 15 articles. Intermediates of glycolysis, Krebs cycle, β oxidation of long chain fatty acids, pentose phosphate pathway, nucleoside metabolism, branched chain amino acid metabolism, aromatic amino acids metabolism, sulfur-containing amino acids metabolism were significantly changed after BPA exposure, suggesting BPA had a highly complex toxic effects on organism which was consistent with existing studies. The biomarkers most consistently associated with BPA exposure were lactate and choline.

Conclusion

Existing metabolomics studies of BPA exposure present heterogeneous findings regarding metabolite profile characteristics. We need more evidence from target metabolomics and epidemiological studies to further examine the reliability of these biomarkers which link to low, environmentally relevant, exposure of BPA in human body.
  相似文献   
992.

Background  

The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin.  相似文献   
993.

Background

All Helicobacter pylori-infected patients are recommended for eradication with an appropriate regimen in each geographic area. The choice of the therapy is somewhat dependent on the antimicrobial susceptibility. The rate of clarithromycin resistance has been increasing and is associated with failure; thus, susceptibility testing is recommended before triple therapy with clarithromycin. However, antimicrobial susceptibility testing is not yet clinically available and an alternative newly developed acid inhibitor vonoprazan is used for triple therapy in Japan. The aim of this study was to determine whether vonoprazan-based triple therapy is plausible treatment in H. pylori eradication.

Methods

A retrospective observational study of H. pylori eradication was conducted in a single institute. The patients who requested antimicrobial susceptibility testing were treated with susceptibility-guided proton pump inhibitor-based triple therapy in International University of Health and Welfare Hospital from 2013 to 2016. Other patients were treated with empirical treatment with a proton pump inhibitor. From 2015 to 2016, vonoprazan-based triple treatment (vonoprazan, 20 mg; amoxicillin, 750 mg; and clarithromycin, 200 or 400 mg, b.i.d.) was conducted, and its effectiveness was compared with susceptibility-guided proton pump inhibitor-based triple therapy. We also investigated the improvement in eradication rate when antimicrobial susceptibility testing was performed, and compared the outcomes of vonoprazan-based and proton pump inhibitor-based empirical therapy.

Results

A total of 1355 patients who received first-line eradication treatment were enrolled in the present study. The eradication rates of the empirical proton pump inhibitor-based therapy and the vonoprazan-based therapy group in a per-protocol analysis were 86.3% (95% CI 83.8–88.8) and 97.4% (95% CI 95.7–99.1), respectively. In 212 patients who received antimicrobial susceptibility testing, the rate of clarithromycin resistant was 23.5% and the eradication rate in susceptibility-guided treatment was 95.7% (95% CI 92.9–98.4). The difference between susceptibility-guided and vonoprazan-based therapy was ??1.7% (95% CI ??4.9 to 1.5%), and the non-inferiority of vonoprazan-based triple therapy was confirmed.

Conclusions

Vonoprazan-based triple therapy was effective as susceptibility-guided triple therapy for H. pylori eradication. An empirical triple therapy with vonoprazan is preferable even in area with high rates of clarithromycin-resistance.Trial registration The study was retrospectively registered in University Hospital Medical Information Network (UMIN000032351)
  相似文献   
994.
The plasma membrane transport proteins belong to SoLute Carrier 15 (SLC15) family and two members of this family have been characterized extensively in higher vertebrates, namely PEPT1 and PEPT2. Despite many efforts have made to define a pharmacophore model for efficient binding and transporting of substrates, there is not a comprehensive study performed to elucidate the evolutionary mechanisms among the SLC15 family members and to statistically evaluate sequence conservation and functional divergence between members. In this study, we compared and contrasted the rates and patterns of molecular evolution of 2 PEPT genes. Phylogenetic tree assembly with all available vertebrate PEPTs suggests that the PEPTs originated by duplications and diverged from a common protein at the base of the eukaryotic tree. Topological structure demonstrates both members share the similar hydrophobic domains (TMDs), which have been constrained by purifying selection. Although both genes show qualitatively similar patterns, their rates of evolution differ significantly due to an increased rate of synonymous substitutions in the structural domains in one copy, suggesting substantial differences in functional constraint on each gene. Site-specific profiles were established by posterior probability analysis revealing significantly divergent regions mainly locate at the hydrophobic region between predicted transmembrane domains 9 and 10 of the proteins. Thus, these results provide the evidence that several amino acid residues with reduced selective constraints are largely responsible for functional divergence between the paralogous PEPTs. These findings may provide a starting point for further experimental verifications.  相似文献   
995.

Background

The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.

Results

Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.

Conclusions

Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.
  相似文献   
996.
Horizontal gene transfer (HGT), non-hereditary transfer of genetic material between organisms, accounts for a significant proportion of the genetic variability in bacteria. In Gram negative bacteria, the nucleoid-associated protein H-NS silences unwanted expression of recently acquired foreign DNA. This, in turn, facilitates integration of the incoming genes into the regulatory networks of the recipient cell. Bacteria belonging to the family Enterobacteriaceae express an additional protein, the Hha protein that, by binding to H-NS, potentiates silencing of HGT DNA. We provide here an overview of Hha-like proteins, including their structure and function, as well as their evolutionary relationship. We finally present available information suggesting that, by expressing Hha-like proteins, bacteria such as Escherichia coli facilitate HGT incorporation and hence, the impact of HGT in their genetic diversity.  相似文献   
997.

Background  

Malaria parasite secretes various proteins in infected RBC for its growth and survival. Thus identification of these secretory proteins is important for developing vaccine/drug against malaria. The existing motif-based methods have got limited success due to lack of universal motif in all secretory proteins of malaria parasite.  相似文献   
998.
The total energies, growth patterns, equilibrium geometries, relative stabilities, hardnesses, intramolecular charge transfer, and magnetic moments of HoSi n (n?=?12–20) clusters have been reexamined theoretically using two different density functional schemes in combination with relativistic small-core Stuttgart effective core potentials (ECP28MWB) for the Ho atoms. The results show that when n?=?12–15, the most stable structures are predicted to be exohedral frameworks with a quartet ground state, but when n?=?16–20, they are predicted to be endohedral frameworks with a sextuplet ground state. These trend in stability across the clusters (gauged from their dissociation energies) was found to be approximately the same regardless of the DFT scheme used in the calculations, with HoSi13, HoSi16, HoSi18, and HoSi20 calculated to be more stable than the other clusters. The results obtained for cluster hardness indicated that doping the Ho atom into Si13 and Si16 leads to the most stable HoSi n clusters, while doping Ho into the other Si n clusters increases the photochemical sensitivity of the cluster. Analyses of intracluster charge transfer and magnetic moments revealed that charge always shifts from the Ho atom to the Si n cluster during the creation of exohedral HoSi n (n?=?12–15) structures. However, the direction of charge transfer is reversed during the creation of endohedral HoSi n (n?=?16–20) structures, which implies that Ho acts as an electron acceptor when it is encapsulated in the Si n cage. Furthermore, when the most stable exohedral HoSi n (n?=?12–15) structures are generated, the 4f electrons of Ho are virtually unchanged and barely participate in intracluster bonding. However, in the most stable endohedral HoSi n (n?=?16–20) frameworks, a 4f electron does participate in bonding. It does this by transferring to the 5d orbital, which hybridizes with the 6s and 6p orbitals and then interacts with Si valence sp orbitals. Meanwhile, the total magnetic moments of the HoSi n (n?=?16–20) clusters are considerably higher than those of HoSi n (n?=?12–15). Interestingly, the endohedral HoSi16 and HoSi20 clusters can be viewed as the most suitable building blocks for novel high-density magnetic storage nanomaterials and for novel optical and optoelectronic photosensitive nanomaterials, respectively.  相似文献   
999.
Invasive species have had devastating impacts on the fauna and flora of the Hawaiian Islands. While the negative effects of some invasive species are obvious, other species are less visible, though no less important. Aphids (Homoptera: Aphididae) are not native to Hawai’i but have thoroughly invaded the Island chain, largely as a result of anthropogenic influences. As aphids cause both direct plant feeding damage and transmit numerous pathogenic viruses, it is important to document aphid distributions and ranges throughout the archipelago. On the basis of an extensive survey of aphid diversity on the five largest Hawaiian Islands (Hawai’i, Kaua’i, O’ahu, Maui, and Moloka’i), we provide the first evidence that invasive aphids feed not just on agricultural crops, but also on native Hawaiian plants. To date, aphids have been observed feeding and reproducing on 64 native Hawaiian plants (16 indigenous species and 48 endemic species) in 32 families. As the majority of these plants are endangered, invasive aphids may have profound impacts on the island flora. To help protect unique island ecosystems, we propose that border vigilance be enhanced to prevent the incursion of new aphids, and that biological control efforts be renewed to mitigate the impact of existing species.  相似文献   
1000.
An early event in the formation of the serotonergic synapse by the Retzius (R) onto the pressure-sensitive (P) neurons of the leech is the elimination of an extrasynaptic response to transmitter from sites of contact on the postsynaptic cell. This event during synapse formation is cell-specific in that it is elicited in vitro by contact with the presynaptic R cell but not with other neurons. In the study reported here, we investigated the nature of this interaction between R and P neurons. The loss of the extrasynaptic response of the P cell was elicited by contact with R cells fixed in a mild paraformaldehyde solution, but not by R cells treated with the proteolytic enzyme trypsin prior to fixation. As well, a variety of lectins were assayed for their ability to interfere with synapse formation. The transmitter responses of P cells plated on lectin-coated substrates were unaffected. However, exposure of the R cell to the lectin wheat germ agglutinin (WGA), but not to other lectins, prior to pairing prevented the loss of the extrasynaptic response in contacted P cells and blocked the formation of the R? P synapse in culture. We conclude that recognition by the P cell of the R cell during synapse formation may be mediated by an R cell-specific surface protein which binds wheat germ agglutinin. 1994 John Wiley & Sons, Inc.  相似文献   
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