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41.
Objectives: Fine needle aspiration cytology (FNAC) of the thyroid is a non-invasive, cost-effective screening procedure that is valuable for distinguishing neoplastic lesions from non-neoplastic nodules. The aim of this study was to determine the diagnostic accuracy of FNACs performed at our institution by correlating FNAC results with histopathological diagnoses.
Methods: Two hundred and seventy-one aspiration cytology specimens followed by thyroidectomy were included in the study, and the results of 260 adequate FNACs were compared with their histological diagnoses.
Results: The sensitivity and specificity of thyroid FNAC for detecting neoplasia were 92.6% and 91.6%, respectively. There were 15 (5.7%) false positives and six (2.3%) false negatives.
Conclusions: The results showed that follicular cells that exhibit some of the features of papillary carcinoma could be observed in a cytology slide of Hashimoto's thyroiditis, leading to a diagnostic pitfall. In addition, cellularity and overlapping cytological criteria in hyperplasia might lead to a false diagnosis. 相似文献
Methods: Two hundred and seventy-one aspiration cytology specimens followed by thyroidectomy were included in the study, and the results of 260 adequate FNACs were compared with their histological diagnoses.
Results: The sensitivity and specificity of thyroid FNAC for detecting neoplasia were 92.6% and 91.6%, respectively. There were 15 (5.7%) false positives and six (2.3%) false negatives.
Conclusions: The results showed that follicular cells that exhibit some of the features of papillary carcinoma could be observed in a cytology slide of Hashimoto's thyroiditis, leading to a diagnostic pitfall. In addition, cellularity and overlapping cytological criteria in hyperplasia might lead to a false diagnosis. 相似文献
42.
Salmonella Typhimurium contains 13 operons coding for fimbriae with unique binding specificities to host epithelial surfaces. stj operon is only detected in S. Typhimurium genome suggesting that Stj fimbria may effect serovarspecific virulence characteristics. In this study, the
role of stj fimbrial operon in the long-term persistence of S. Typhimurium was identified by competitive infection experiment in genetically resistant mouse (CBA) model system. Knock-out
mutation of stjA (major subunit of the Stj fimbria) gene reduced recovery of S. Typhimurium from fecal samples and its colonization to spleen, cecum and mesenteric lymph nodes over a 34-day time period
(p < 0.05). This data indicate that stj fimbrial operon has a role in long-term intestinal persistence of S. Typhimurium in CBA mice. 相似文献
43.
Macro and micromorphological properties of intact and mature seeds of 12 taxa (species and varieties) belonging to Nigella L. (Ranunculaceae) was investigated using light and scanning electron microscopy. Material studied covers 11 species of 15
Turkish Nigella. Studied taxa were divided into two types. Type I has ovate to orbicular seeds that includes four species. Type II has triquedrous
seeds and includes seven species. Type II was subdivided into two. Type IIa has triquedrous to subpyramidal seeds (five species)
and Type IIb has triquedrous to subglobose seeds (two species). Further segregation was performed micromorphologically and
an identification key of studied Nigella taxa was given. Studied Nigella taxa have a diverse macro and micromorphological characters that utilize to separate them from each other to assess the systematics
of Nigella. 相似文献
44.
Ann-Charlotte Johansson Hanna Appelqvist Cathrine Nilsson Katarina Kågedal Karin Roberg Karin Öllinger 《Apoptosis : an international journal on programmed cell death》2010,15(5):527-540
Lysosomal membrane permeabilization (LMP) occurs in response to a large variety of cell death stimuli causing release of cathepsins
from the lysosomal lumen into the cytosol where they participate in apoptosis signaling. In some settings, apoptosis induction
is dependent on an early release of cathepsins, while under other circumstances LMP occurs late in the cell death process
and contributes to amplification of the death signal. The mechanism underlying LMP is still incompletely understood; however,
a growing body of evidence suggests that LMP may be governed by several distinct mechanisms that are likely engaged in a death
stimulus- and cell-type-dependent fashion. In this review, factors contributing to permeabilization of the lysosomal membrane
including reactive oxygen species, lysosomal membrane lipid composition, proteases, p53, and Bcl-2 family proteins, are described.
Potential mechanisms to safeguard lysosomal integrity and confer resistance to lysosome-dependent cell death are also discussed. 相似文献
45.
Mesangioproliferative glomerulonephritis is a disease that has a high incidence in humans. In this disease, the proliferation of glomerular mesangial cells and the production of extracellular matrix are important. In recent years, the RNAi technology has been widely used in the treatment of various diseases due to its capability to inhibit the gene expression with high specificity and targeting. The objective of this study was to decrease mesangial cell proliferation by knocking down PDGF-B and its receptor, PDGFR-β. To be able to use small interfering RNAs (siRNAs) in the treatment of this disease successfully, it is necessary to develop appropriate delivery systems. Chitosan, which is a biopolymer, is used as a siRNA delivery system in kidney drug targeting. In order to deliver siRNA molecules targeted at PDGF-B and PDGFR-β, chitosan/siRNA nanoplexes were prepared. The in vitro characterization, transfection studies, and knockdown efficiencies were studied in immortalized and primary rat mesangial cells. In addition, the effects of chitosan nanoplexes on mesangial cell proliferation and migration were investigated. After in vitro transfection, the PDGF-B and PDGFR-β gene silencing efficiencies of PDGF-B and PDGFR-β targeting siRNA-containing chitosan nanoplexes were 74 and 71% in immortalized rat mesangial cells and 66 and 62% in primary rat mesangial cells, respectively. siPDGF-B- and siPDGFR-β-containing nanoplexes indicated a significant decrease in mesangial cell migration and proliferation. These results suggested that mesangial cell proliferation may be inhibited by silencing of the PDGF-B signaling pathway. Gene silencing approaches with chitosan-based gene delivery systems have promise for the efficient treatment of renal disease. 相似文献
46.
Hypolimnetic phosphorus and nitrogen dynamics in a small,eutrophic lake with a seasonally anoxic hypolimnion 总被引:4,自引:0,他引:4
In situ estimates of sediment nutrient flux are necessary to understand seasonal variations in internal loading in lakes.
We investigated the sources and sinks of nutrients in the hypolimnion of a small (0.33 km2), relatively shallow (18 m max. depth), eutrophic lake (Lake Okaro, New Zealand) in order to determine changes in sediment
nutrient fluxes resulting from a whole lake sediment capping trial using a modified zeolite phosphorus inactivation agent
(Z2G1). Sediment nutrient fluxes in the hypolimnion were estimated as the residual term in a nutrient budget model that accounted
for mineralisation of organic nutrients, nutrient uptake by phytoplankton and mixing, nitrification, adsorption/desorption
and diffusion of dissolved nutrients at the thermocline. Of the total hypolimnetic phosphate and ammonium fluxes during one
period of seasonal stratification (2007–08), up to 60 and 50%, respectively, were derived from the bottom sediments, 18 and
24% were due to mineralisation of organic species, 36 and 28% were due to phytoplankton uptake and 9 and 6% were from diffusion
across the thermocline. Adsorption/desorption of phosphate to suspended solids and nitrification were of minor (<8%) importance
to the total fluxes. Any reduction in sediment nutrient release by Z2G1 was small compared with both the total sediment nutrient
flux and the sum of other hypolimnetic fluxes. Uneven sediment coverage of Z2G1 may have been responsible for the limited
effect of the sediment capping layer formed by Z2G1. 相似文献
47.
Human immunodeficiency virus type 1 (HIV-1) protease (PR) permits viral maturation by processing the gag and gag-pro-pol polyproteins. HIV-1 PR inhibitors (PIs) are used in combination antiviral therapy but the emergence of drug resistance has limited their efficacy. The rapid evolution of HIV-1 necessitates consideration of drug resistance in novel drug design. Drug-resistant HIV-1 PR variants no longer inhibited efficiently, continue to hydrolyze the natural viral substrates. Though highly diverse in sequence, the HIV-1 PR substrates bind in a conserved three-dimensional shape we termed the substrate envelope. Earlier, we showed that resistance mutations arise where PIs protrude beyond the substrate envelope, because these regions are crucial for drug binding but not for substrate recognition. We extend this model by considering the role of protein dynamics in the interaction of HIV-1 PR with its substrates. We simulated the molecular dynamics of seven PR-substrate complexes to estimate the conformational flexibility of the bound substrates. Interdependence of substrate-protease interactions might compensate for variations in cleavage-site sequences and explain how a diverse set of sequences are recognized as substrates by the same enzyme. This diversity might be essential for regulating sequential processing of substrates. We define a dynamic substrate envelope as a more accurate representation of PR-substrate interactions. This dynamic substrate envelope, described by a probability distribution function, is a powerful tool for drug design efforts targeting ensembles of resistant HIV-1 PR variants with the aim of developing drugs that are less susceptible to resistance. 相似文献
48.
Zainab Saad Yusuf Tugba Kevser Uysal Ender Simsek Alessio Nocentini Sameh Mohamed Osman Claudiu T. Supuran
zen
zensoy Güler 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):1340
Carbonic anhydrases (EC 4.2.1.1) catalyse the reversible hydration of CO2 into bicarbonate and protons. As a hypoxia-sensitive and tumour-associated isoform, isoform CA IX, is significantly overexpressed in various malignancies, being a validated target for new anticancer/antimetastatic drugs. A multitude of studies has shown that CA IX inhibition decreases cancer cell proliferation and metastasis through pHe/pHi modulation and enhancement of ferroptosis among others. Numerous studies demonstrated increased efficacy of cytotoxic drugs combined with CA inhibitors (CAIs) in various cancer types. We tested the inhibitory effect of boric acid (BA), an inorganic Lewis acid, on CA IX as well as other isoforms (CA I, II, and XII). BA acted as a millimolar in vitro CAI, decreased proliferation of two cancer cell lines, although not strong correlations between the in vitro inhibition and in vivo effects were observed. The mechanism of antiproliferative action of BA should be investigated in more detail. 相似文献
49.
Mustafa Ark Aysun Özdemir Belgin Polat 《Apoptosis : an international journal on programmed cell death》2010,15(12):1494-1506
Ouabain, a specific Na+/K+-ATPase inhibitor, has recently been identified as a mammalian hormone. Its elevated concentrations in human plasma have also
been associated with pathogenesis of several diseases. Recent studies have shown that ouabain induces aponecrotic cell death
in a cell-type- and dose-dependent manner. However, the exact mechanism of ouabain-induced cell death is not fully understood.
The Rho GTPase effectors Rho kinases-1 and -2 (Rock-1 and Rock-2) which play central roles in the organization of the actin
cytoskeleton, involve in several models of apoptosis. In this study, we investigated the possible involvement of Rocks in
ouabain-induced human umbilical vein endothelial cell (HUVEC) apoptosis. Ouabain treatment resulted in loss of cell–cell and
cell–substratum adhesion and apoptotic blebbing. Pretreatment of cells with Y-27632, a specific Rock inhibitor, resulted in
the inhibition of cell-to-cell detachment and formation of membrane blebs. However, Y-27632 did not prevent ouabain-induced
cell–substratum detachment. Instead, treatment with Y-27632 actually accelerated this process. Ouabain treatment induced cleavage
of Rock-1 and Rock-2, which was prevented by caspase-3 and caspase-2 specific inhibitors z-DEVD-fmk and z-VDVAD-fmk, respectively.
Ouabain-induced Rock-2 cleavage generated a fragment of approximately 140 kDa corresponding to the consensus sequence of caspase-2
on the carboxy terminus of Rock-2. Although it has been previously shown that Rock-2 was cleaved by caspase-2, we have identified
here a novel cleavage site and fragment of Rock-2. Our data indicate that ouabain induces both Rock-1 and Rock-2 cleavage
via caspase-dependent mechanisms and provide evidence that Rocks are involved in ouabain-induced cell-to-cell detachment and
apoptosis. 相似文献
50.