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91.
Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP) were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages.  相似文献   
92.
We have identified a new class of microtubule-binding compounds—noscapinoids—that alter microtubule dynamics at stoichiometric concentrations without affecting tubulin polymer mass. Noscapinoids show great promise as chemotherapeutic agents for the treatment of human cancers. To investigate the structural determinants of noscapinoids responsible for anti-cancer activity, we tested 36 structurally diverse noscapinoids in human acute lymphoblastic leukemia cells (CEM). The IC50 values of these noscapinoids vary from 1.2 to 56.0 μM. Pharmacophore models of anti-cancer activity were generated that identify two hydrogen bond acceptors, two aromatic rings, two hydrophobic groups, and one positively charged group as essential structural features. Additionally, an atom-based quantitative structure–activity relationship (QSAR) model was developed that gave a statistically satisfying result (R 2 = 0.912, Q 2 = 0.908, Pearson R = 0.951) and effectively predicts the anti-cancer activity of training and test set compounds. The pharmacophore model presented here is well supported by electronic property analysis using density functional theory at B3LYP/3-21*G level. Molecular electrostatic potential, particularly localization of negative potential near oxygen atoms of the dimethoxy isobenzofuranone ring of active compounds, matched the hydrogen bond acceptor feature of the generated pharmacophore. Our results further reveal that all active compounds have smaller lowest unoccupied molecular orbital (LUMO) energies concentrated over the dimethoxy isobenzofuranone ring, azido group, and nitro group, which is indicative of the electron acceptor capacity of the compounds. Results obtained from this study will be useful in the efficient design and development of more active noscapinoids.  相似文献   
93.
ABSTRACT: BACKGROUND: Despite the availability of evidence-based psychotherapies for depression and anxiety, they are underused in non-mental health specialty settings such as primary care. Hybrid effectiveness-implementation designs have the potential to evaluate clinical and implementation outcomes of evidence-based psychotherapies to improve their translation into routine clinical care practices. METHODS: This protocol article discusses the study methodology and implementation strategies employed in an ongoing, hybrid, type 2 randomized controlled trial with two primary aims: (1) to determine whether a brief, manualized cognitive behavioral therapy administered by Veterans Affairs Primary Care Mental Health Integration program clinicians is effective in treating depression and anxiety in a sample of medically ill (chronic cardiopulmonary diseases) primary care patients and (2) to examine the acceptability, feasibility, and preliminary outcomes of a focused implementation strategy on improving adoption and fidelity of brief cognitive behavioral therapy at two Primary Care-Mental Health Integration clinics. The study uses a hybrid type 2 effectiveness/implementation design to simultaneously test clinical effectiveness and to collect pilot data on a multifaceted implementation strategy that includes an online training program, audit and feedback of session content, and internal and external facilitation. Additionally, the study engages the participation of an advisory council consisting of stakeholders from Primary Care-Mental Health Integration, as well as regional and national mental health leaders within the Veterans Administration. It targets recruitment of 320 participants randomized to brief cognitive behavioral therapy (n = 200) or usual care (n = 120). Both effectiveness and implementation outcomes are being assessed using mixed methods, including quantitative evaluation (e.g., intent-to-treat analyses across multiple time points) and qualitative methods (e.g., focus interviews and surveys from patients and providers). Patient-effectiveness outcomes include measures of depression, anxiety, and physical health functioning using blinded independent evaluators. Implementation outcomes include patient engagement and adherence and clinician brief cognitive behavioral therapy adoption and fidelity. CONCLUSIONS: Hybrid designs are needed to advance clinical effectiveness and implementation knowledge to improve healthcare practices. The current article describes the rationale and challenges associated with the use of a hybrid design for the study of brief cognitive behavioral therapy in primary care. Although trade-offs exist between scientific control and external validity, hybrid designs are part of an emerging approach that has the potential to rapidly advance both science and practice. Trial registration NCT01149772 at http://www.clinicaltrials.gov/ct2/show/NCT01149772.  相似文献   
94.
95.
Alterations in glucose metabolism have been demonstrated for diverse disorders ranging from heart disease to cancer. The first step in glucose metabolism is carried out by the hexokinase (HK) family of enzymes. HKI and II can bind to mitochondria through their N-terminal hydrophobic regions, and their overexpression in tissue culture protects against cell death. In order to determine the relative contributions of mitochondrial binding and glucose-phosphorylating activities of HKs to their overall protective effects, we expressed full-length HKI and HKII, their truncated proteins lacking the mitochondrial binding domains, and catalytically inactive proteins in tissue culture. The overexpression of full-length proteins resulted in protection against cell death, decreased levels of reactive oxygen species, and possibly inhibited mitochondrial permeability transition in response to H2O2. However, the truncated and mutant proteins exerted only partial effects. Similar results were obtained with primary neonatal rat cardiomyocytes. The HK proteins also resulted in an increase in the phosphorylation of voltage-dependent anion channel (VDAC) through a protein kinase C (PKC)-dependent pathway. These results suggest that both glucose phosphorylation and mitochondrial binding contribute to the protective effects of HKI and HKII, possibly through VDAC phosphorylation by PKC.  相似文献   
96.
Glutaredoxins (Grxs) are small oxidoreductases that reduce disulphide bonds or protein-glutathione mixed disulphides. More than 30 distinct grx genes are expressed in higher plants, but little is currently known concerning their functional diversity. This study presents biochemical and spectroscopic evidence for incorporation of a [2Fe-2S] cluster in two heterologously expressed chloroplastic Grxs, GrxS14 and GrxS16, and in vitro cysteine desulphurase-mediated assembly of an identical [2Fe-2S] cluster in apo-GrxS14. These Grxs possess the same monothiol CGFS active site as yeast Grx5 and both were able to complement a yeast grx5 mutant defective in Fe-S cluster assembly. In vitro kinetic studies monitored by CD spectroscopy indicate that [2Fe-2S] clusters on GrxS14 are rapidly and quantitatively transferred to apo chloroplast ferredoxin. These data demonstrate that chloroplast CGFS Grxs have the potential to function as scaffold proteins for the assembly of [2Fe-2S] clusters that can be transferred intact to physiologically relevant acceptor proteins. Alternatively, they may function in the storage and/or delivery of preformed Fe-S clusters or in the regulation of the chloroplastic Fe-S cluster assembly machinery.  相似文献   
97.
Naik AK  Raghavan SC 《DNA Repair》2008,7(8):1384-1391
P1 nuclease is one of the most extensively used single-strand DNA specific nucleases in molecular biology. In modern biology, it is used as an enzymatic probe to detect altered DNA conformations. It is well documented that P1 cleaves single-stranded nucleic acids and single-stranded DNA regions. The fact that P1 can act under a wide range of conditions, including physiological pH and temperature make it the most commonly used enzymatic probe in DNA structural studies. Surprisingly, to this date, there is no study to characterize the influence of length of mismatches on P1 sensitivity. Using a series of radioactively labeled oligomeric DNA substrates-containing mismatches, we find that P1 nuclease cleavage is dependent on the length of mismatches. P1 does not cleave DNA when there is a single-base mismatch. P1 cleavage efficiency is optimum when mismatch length is 3 nt or more. Changing the position of the mismatches also does not make any difference in cleavage efficacy. These novel findings on P1 properties have implications for its use in DNA structure and DNA repair studies.  相似文献   
98.
The vast majority of cases of T cell large granular lymphocyte (T-LGL) leukemia have a CD3+, CD4−, CD8+ phenotype and express the αβ T cell receptor. Whether the rare γδ variant should be included in the same diagnostic category is currently unclear. Two well-characterized cases of γδ T-LGL leukemia were identified by our laboratory in 2007. These two cases and other reports of γδ T-LGL leukemia were compared with the common αβ variant. Other than more often being negative for both CD4 and CD8 (in about 35% to 40% of cases), the γδ variant of T-LGL leukemia is similar to the common αβ type in virtually all respects and should be included in the general category of T-LGL leukemia. However, it is important to exclude other more aggressive γδ T cell lymphoproliferative disorders.  相似文献   
99.
Junctional adhesion molecule (JAM) is involved in tight junction (TJ) formation in epithelial cells. Three JAMs (A, B, and C) are expressed in rat hepatocytes, but only rat JAM-A is present in polarized WIF-B cells, a rat-human hepatic line. We used knockdown (KD) and overexpression in WIF-B cells to determine the role of JAM-A in the development of hepatic polarity. Expression of rat JAM-A short hairpin RNA resulted in approximately 50% KD of JAM-A and substantial loss of hepatic polarity, as measured by the absence of apical cysts formed by adjacent cells and sealed by TJ belts. When inhibitory RNA-resistant human JAM-A (huWT) was expressed in KD cells, hepatic polarity was restored. In contrast, expression of JAM-A that either lacked its PDZ-binding motif (huDeltaC-term) or harbored a point mutation (T273A) did not complement, indicating that multiple sites within JAM-A's cytoplasmic tail are required for the development of hepatic polarity. Overexpression of huWT in normal WIF-B cells unexpectedly blocked WIF-B maturation to the hepatic phenotype, as did expression of three huJAM-A constructs with single point mutations in putative phosphorylation sites. In contrast, huDeltaC-term was without effect, and the T273A mutant only partially blocked maturation. Our results show that JAM-A is essential for the development of polarity in cultured hepatic cells via its possible phosphorylation and recruitment of relevant PDZ proteins and that hepatic polarity is achieved within a narrow range of JAM-A expression levels. Importantly, formation/maintenance of TJs and the apical domain in hepatic cells are linked, unlike simple epithelia.  相似文献   
100.
Cholinesterases (ChEs) are classified as either acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) based on their substrate and inhibitor specificity. Organophosphate and carbamate compounds commonly represented by herbicides, pesticides, and nerve gases irreversibly inhibit ChEs. Therefore, exposure to organophosphates and carbamates is normally assessed by measuring ChE activity in blood. There are two approaches for measuring AChE and BChE activity present in whole blood: (1) separating blood into erythrocytes, which contain only AChE, and plasma which contains only BChE, to measure their activity individually, or (2) use a BChE-specific inhibitor to measure the activity of AChE in whole blood. A number of studies have reported the use of different inhibitors for the simultaneous measurement of AChE and BChE activities. However, the inhibitors used for completely inhibiting BChE activity also inhibited AChE activity leading to errors in reported values. The goal of this study was to find the most accurate and simple method for the simultaneous determination of AChE and BChE activity in animal whole blood. Solutions containing human AChE and BChE in various proportions were prepared and AChE and BChE activities were measured using three reported methods. Results demonstrate that ethopropazine and (-) huperzine A appear to be the most specific ChE inhibitors. Preliminary results with human and animal whole blood suggest that 20muM ethopropazine and 500nM (-) huperzine A can be used for measuring AChE and BChE activities across species.  相似文献   
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