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991.
992.
A series of novel chalcones and bis-chalcones containing boronic acid moieties has been synthesized and evaluated for antitumor activity against the human breast cancer MDA-MB-231 (estrogen receptor-negative) and MCF7 (estrogen receptor-positive) cell lines and against two normal breast epithelial cell lines, MCF-10A and MCF-12A. These molecules inhibited the growth of the human breast cancer cell lines at low micromolar to nanomolar concentrations, with five of them (1-4, 9) showing preferential inhibition of the human breast cancer cell lines. Furthermore, bis-chalcone 8 exhibited a more potent inhibition of colon cancer cells expressing wild-type p53 than of an isogenic cell line that was p53-null.  相似文献   
993.
The inhibition of prostaglandin (PG) synthetase by nonsteroidal anti-inflammatory drugs (NSAID) is not well understood. Co-factors (glutathione and hydroquinone) are needed for maximum enzymatic activity in vitro, and we suggest that NSAID might inhibit PG synthetase partly by interfering with co-factor induced stimulation of the enzyme. This hypothesis was tested by: A) Examining the effect of glutathione, noradrenaline and hydroquinone on bull seminal vesicle (BSV) PG synthetase in vitro. The stimulatory effects were concentration-dependent. B) Three structurally distinct NSAID, indomethacin, aspirin and paracetamol, inhibited the stimulation by each co-factor in a concentration-related manner. Drug effectiveness also depended on the concentration of co-factor.  相似文献   
994.
The gene for the Salmonella enterica serovar Enteritidis fimbrial protein SefA was cloned into an Escherichia coli surface expression vector and confirmed by Western blot assay. E. coli clones expressing SefA attached to avian ovary granulosa cells and HEp-2 cells, providing evidence for the involvement of SefA in the ability of Salmonella to attach to eukaryotic cells.During the 1980s to 1990s, the worldwide increase in human Salmonella enterica serovar Enteritidis infections was associated with the consumption of contaminated eggs and egg products (13, 26, 28). In the United States, grade A shell eggs were identified as a major source contributing to Salmonella infections (19, 26, 29), and the percentage of S. Enteritidis among all Salmonella isolated from outbreaks increased from 5% to 26% from 1976 to 1996 (4). Although outbreak-associated cases due to S. Enteritidis decreased from 974 during 1998 to 2000 to 692 cases in 2004 to 2006, the 28 outbreaks in 2006 still remained above the Healthy People 2010 target of 22 (6). Despite efforts directed at reducing egg-related outbreaks, S. Enteritidis infections are still among those with the highest incidence of the seven most-reported serotypes of Salmonella (5).The large proportion of S. Enteritidis serotypes involved in food-borne outbreaks is partly attributed to the adherence elicited by surface fimbriae. Fimbriae are nonflagellar filamentous surface appendages which consist of helically arranged repeating subunit proteins called fimbrins (24). Four serologically distinct fimbriae of S. Enteritidis have been characterized according to their size (kDa) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels: SEF21, SEF18, SEF17, and SEF14 (9-11, 21). Fimbriae can mediate the aggregation of bacteria and their attachment to inert surfaces (2) and to the surfaces of eukaryotic cells, especially to carbohydrate receptors (8, 11, 36).SEF14 fimbriae are detected in all S. Enteritidis strains and are not widely distributed among the Enterobacteriaceae (10). These fimbriae consist of a repeating major subunit protein of 14.3 kDa (SefA) encoded by the gene sefA (9, 33). The results of studies by Peralta et al. (25) and Thiagarajan et al. (31) indicate that SEF14 fimbriae may have a role in pathogenesis by mediating attachment to eukaryotic cells. We focused on SEF14 fimbriae because of their limited distribution and their role as a main immunological target in the serological response to infection by S. Enteritidis in chickens (12). The objectives of this study were to clone and investigate the functional properties of the SEF14 fimbrin, SefA, as part of a fusion protein in Escherichia coli and to determine whether it could mediate adherence to tissue culture cells in vitro.Bacterial strains, tissue culture cells, and plasmids used in this study are described in Table Table1.1. Bacterial cultures were grown in LB medium (Fisher Scientific, Raleigh, NC) supplemented with 0.2% glucose and shaken at 220 revolutions min−1 or in colonization factor broth (30) at 37°C. Chloramphenicol (Cm; 10 μg ml−1) and ampicillin (Amp; 50 μg ml−1) were added as needed (Sigma-Aldrich, St. Louis, MO). Avian ovary granulosa cells were grown in 5% CO2 atmosphere at 37°C in M199 medium supplemented with 26 mM NaHCO3, 0.1% bovine serum albumin, 100 U ml−1 penicillin G, and 100 μg ml−1 streptomycin sulfate (Gibco-BRL, Gaithersburg, MD). HEp-2 cells were obtained from ATCC (Rockville, MD) and grown in 5% CO2 atmosphere at 37°C in minimum essential medium (Sigma-Aldrich), pH 7.2, supplemented with 26 mM NaHCO3, 7% fetal bovine serum, 100 U ml−1 penicillin G, and 100 μg ml−1 streptomycin sulfate (Gibco-BRL and Sigma-Aldrich).

TABLE 1.

Bacterial strains, tissue culture cells, and plasmids
Bacterial strain, tissue culture cell line, or plasmidRelevant characteristicsSource or reference
Strains
    S. Enteritidis CDC9Phage type 8, SEF14+sefA+A. M. Saeed
    E. coli JM109endA1 recA1 gyrA96 thi hsdR17 (rK mK+) mcrB+ relA1 supE44 λ Δ(lac-proAB) supE44 [F′ traD36 proAB lacIqZΔM15]B. Olwin
Tissue culture cell lines
    HEp-2 cellsEpidermoid carcinoma isolated from human larynxATCC CCL23
    Granulosa cellsIsolated from chicken ovariesA. M. Saeed
Plasmids
    pTX10112.5 kb, Ampr CmrlacIq+lpp-ompA-bla fusion expressed through Plac or PlppG. Georgiou (15)
    pDUG3A11.5 kb, CmrlacIq+lpp-ompA-sefA fusion expressed through Plac or PlppThis study
Open in a separate windowPrimers were designed to amplify the known sefA sequence (35) corresponding to the mature protein and included restriction sites to facilitate directional cloning of the amplified target to replace the β-lactamase gene in pTX101 (27). E. coli JM109 host cells were then transformed by electroporation (Gene Pulser, Bio-Rad Laboratories, Hercules, CA). In prior studies, derivatives of pTX101 have been used successfully to express several proteins on the outer surface of E. coli cells (16, 17). The Lpp portion of pTX101 serves to localize the fusion protein to the outer membrane, while the OmpA portion traverses the outer membrane and directs the product of the cloned gene (i.e., β-lactamase or SefA) to the surface.Membrane fractions were isolated as previously described (7) with the following modifications. Cell suspensions were sonicated with an XL series sonicator (Heat Systems, Farmingdale, NY) at 100 W and then added to ice-cold Tris-Cl, and the remaining bacteria were removed by centrifugation. The total membrane was sedimented by centrifugation (45,000 × g at 4°C) for 1 h and then suspended in Tris-Cl, and the outer membrane was isolated by adding 0.5% (wt/vol) N-lauryl sarcosine (Sigma) and shaking at 200 rpm for 30 min at 22°C to dissolve the inner membrane.Crude SefA was obtained from S. Enteritidis CDC9 as described previously by Feutrier et al. (14). Purified SefA was obtained by the method of Chart (7) with the following modifications. Briefly, crude SefA was run on an SDS-PAGE gel and a portion corresponding to SefA was extracted from gel slices with Z-spin microcentrifuge columns (Pall/Gelman Sciences, Ann Arbor, MI). The purified SefA was vacuum dried and suspended in phosphate-buffered saline buffer.SDS-PAGE was performed according to the method of Laemmli (18), and proteins were visualized with Coomassie blue. An identical gel was prepared for Western blots, and proteins were transferred onto BioTrace polyvinylidene difluoride (Pall/Gelman Sciences). Western blotting was done according to the membrane manufacturer''s instructions (1). SefA monoclonal mouse antibodies 69/25 supplied by C. J. Thorns (Central Veterinary Laboratories, Weybridge, Surrey; 32) were used as the primary antibody; ImmunoPure goat anti-mouse immunoglobulin G(H+L) biotin-conjugated antibodies (Pierce, Rockford, IL) were used as the secondary antibody; and AVIDX-AP, assay buffer (0.1 M diethanolamine, 1.0 mM MgCl2, pH 10.0), I-Block, and CSPD (Applied Biosystems, Bedford, MA) were used in the chemiluminescent detection of the secondary antibodies using X-ray film. SDS-PAGE of total membrane fractions of E. coli JM109(pDUG3A) demonstrated a protein of the expected size for the Lpp-OmpA-SefA fusion protein (∼31 kDa); however, similarly sized proteins were also observed in the control strains [JM109 and JM109(pTX101)] (Fig. (Fig.1A).1A). Western blot analysis confirmed the presence of SefA in the 31-kDa band in the recombinant strain [JM109(pDUG3A)] but not in membrane protein fractions from either the host strain alone (JM109) or the host strain harboring the pTX101 vector (Fig. (Fig.1B).1B). When outer membrane fractions were selectively isolated from the inner membrane, the presence of the 31-kDa SefA fusion protein was more readily detected over the background of proteins of similar size (Fig. (Fig.1C).1C). The data provide further evidence for the localization of the SefA fusion protein in the outer membrane of E. coli JM109(pDUG3A).Open in a separate windowFIG. 1.SDS-PAGE and Western blot of SefA samples using SefA monoclonal antibodies. (A) SDS-PAGE of total membrane fractions collected from cells grown at 37°C. (B) Western blot of SDS-PAGE gel shown in panel A using monoclonal mouse antibodies 69/25 as an immunoprobe for SefA. (C) SDS-PAGE of outer membrane fractions collected from cells grown at 25°C. Lanes: 1, molecular mass standards (99.4, 66.2, 45, 31, 21.5, and 14.4 kDa); 2, crude SefA; 3, purified SefA; 4, E. coli JM109; 5, E. coli JM109(pTX101); 6, E. coli JM109(pDUG3A). Arrows indicate Lpp-OmpA-SefA fusion protein at ∼31 kDa.Attachment assays on avian ovary granulosa and HEp-2 cells were done according to the method of Thiagarajan et al. (30), with some modifications. Briefly, granulosa cells were seeded and grown as a monolayer on sterile coverslips and then washed three times with M199 medium (Gibco), and 1 × 107 CFU of bacterial cells (grown with and without 1% d-mannose) was added to the coverslips. The coverslips were then incubated in a 5% CO2 atmosphere at 37°C for 3 h, after which the cells were washed five times with M199 medium, fixed with methanol, stained with 10% Giemsa stain (Sigma), and examined by light microscopy. Attachment assays with HEp-2 cells were done as described above except that minimum essential medium (Sigma) was used as the wash solution.Peralta et al. (25) showed that in vitro attachment of S. Enteritidis to murine intestinal epithelial cells was reduced by SefA antibodies, suggesting a role for SefA in attachment. Thiagarajan et al. (30) demonstrated attachment of S. Enteritidis to avian ovary granulosa cells that form one of the layers surrounding the yolk in a preovulatory follicle. They suggest that this attachment may be a mechanism precipitating S. Enteritidis infection of hens'' ovaries that may subsequently lead to transovarian transmission to shell eggs. In our study, we compared the attachment of S. Enteritidis CDC9, E. coli JM109(pDUG3A) (sefA clone), and JM109(pTX101) (vector) to both avian granulosa (Fig. (Fig.2)2) and HEp-2 cells (Fig. (Fig.3).3). S. Enteritidis CDC9 demonstrated a mannose-resistant pattern of attachment to both granulosa and HEp-2 cells (Fig. (Fig.2A2A and and3A)3A) while JM109(pTX101) did not attach to these cell lines (Fig. (Fig.2B2B and and3B).3B). However, JM109(pDUG3A), expressing the SefA fusion protein, demonstrated mannose-sensitive attachment to both granulosa and HEp-2 cells, indicating attachment to eukaryotic cell lines attributed to the presence of SefA (Fig. (Fig.2C2C and and3C3C).Open in a separate windowFIG. 2.Attachment of indicated bacterial cells to avian ovary granulosa cells: S. Enteritidis CDC9 (A), E. coli JM109(pTX101) (B), and E. coli JM109(pDUG3A) (C). Cells were stained with 10% Giemsa stain and photographed with a light microscope at ×400 magnification.Open in a separate windowFIG. 3.Attachment of indicated bacterial cells to HEp-2 cells: S. Enteritidis CDC9 (A), E. coli JM109(pTX101) (B), and E. coli JM109(pDUG3A) (C). Cells were stained with 10% Giemsa stain and photographed with a light microscope at ×400 magnification.Thorns (34) reported that both a wild-type S. Enteritidis strain and a sefA mutant were able to attach to HEp-2 cells, indicating that multiple determinants may mediate attachment. This is also indicated by differences in mannose sensitivities of various S. Enteritidis strains (30). The results of the Western blot and cell culture attachment assays suggest that the mannose-sensitive binding of JM109(pDUG3A) is due to the presence of SefA in the outer membrane, since JM109(pTX101) did not possess SefA or show attachment. The data also indicate that the presentation of SefA in a fimbrial structure may not be necessary for binding since nonfimbrial adhesions have been reported to mediate attachment to eukaryotic cells (22). Unfolded SefA protein in the Lpp-OmpA-SefA fusion protein may possibly allow hydrophilic or hydrophobic interactions with granulosa or HEp-2 cells, providing for mannose-sensitive adherence.The data presented herein demonstrate that surface-expressed SefA protein may provide to nonadherent bacteria the property of adherence to eukaryotic cells and constitute further evidence for the involvement of SEF14 fimbriae in binding by S. Enteritidis. Heterologously expressed recombinant fimbrial antigens have been used successfully to induce immune responses in mice and pigs (3, 20). The results of previous studies have indicated that purified SefA protein is highly immunogenic and that SefA antibodies increase the survival rate of mice after challenge with S. Enteritidis from 32% in control mice to 78% in vaccinated mice (23, 25). The data warrant further studies to demonstrate whether the attachment observed in vitro could be demonstrated in vivo for possible applications in the competitive exclusion or induction of an immune response using this vector.  相似文献   
995.

Background

Calpain-3 deficiency causes oxidative and nitrosative stress-induced damage in skeletal muscle of LGMD2A patients, but mitochondrial respiratory chain function and anti-oxidant levels have not been systematically assessed in this clinical population previously.

Methods

We identified 14 patients with phenotypes consistent with LGMD2A and performed CAPN3 gene sequencing, CAPN3 expression/autolysis measurements, and in silico predictions of pathogenicity. Oxidative damage, anti-oxidant capacity, and mitochondrial enzyme activities were determined in a subset of muscle biopsies.

Results

Twenty-one disease-causing variants were detected along the entire CAPN3 gene, five of which were novel (c.338 T>C, c.500 T>C, c.1525-1 G>T, c.2115+4 T>G, c.2366 T>A). Protein- and mRNA-based tests confirmed in silico predictions and the clinical diagnosis in 75% of patients. Reductions in antioxidant defense mechanisms (SOD-1 and NRF-2, but not SOD-2), coupled with increased lipid peroxidation and protein ubiquitination, were observed in calpain-3 deficient muscle, indicating a redox imbalance primarily affecting non-mitochondrial compartments. Although ATP synthase levels were significantly lower in LGMD2A patients, citrate synthase, cytochrome c oxidase, and complex I+III activities were not different from controls.

Conclusions

Despite significant oxidative damage and redox imbalance in cytosolic/myofibrillar compartments, mitochondrial respiratory chain function is largely maintained in skeletal muscle of LGMD2A patients.  相似文献   
996.
Abstract

The purpose of this study was to assess the environmental risk of Balarood Dam in Iran at constructional phase. The scientific methods used in this research were the Environmental Failure Mode and Effects Analysis (EFMEA) and VIKOR. In the process of environmental risk assessment, the EFMEA method was used first to calculate the risk priority number (RPN) for each environmental aspect. The identified risks were ranked based on RPN values in the next stage. Comparison of the RPN values showed that the risk of pollution of Balarood River, with a RPN of 125, is in the first priority. In addition, the environmental risks, identified during the follow-up phase, were weighted by entropy method based on severity, occurrence probability, and extent of pollution.Then, the VIKOR method, as one of the multicriteria decision-making (MCDM) methods, was run to evaluate and prioritize the potential environmental risks. The risk of water pollution under high, medium and low conditions, with a weight of 1,300, 1,000 and 700, was identified as the most important risk of dam construction. Accordingly, the most important corrective action, proposed to mitigate the high priority environmental risks, is to prevent the discharge of sanitary and industrial wastewater into the river.  相似文献   
997.
Batch experiments were performed to determine the cadmium absorption capacity of two plant growth–promoting rhizobacteria at different pH levels and in different cadmium concentrations. Comparison of the mean metal removal from two species of bacteria studied showed that Pseudomonas florescence is the superior species for removing cadmium at all cadmium concentrations. The maximum cadmium absorption by P. florescence and P. putida were at 5 mg/L of cadmium concentration in pH 6 and 7, respectively. The applicability of the Langmuir and Freundlich isotherm models was surveyed. Comparison of two isotherm parameters (Q m and a) further confirmed that P. fluorescence was better at binding cadmium ions (52.6 and 7.7 mg/g, respectively). Adsorption reaction also was considered by Fourier transform infrared (FTIR) spectroscopy. The FTIR analysis implied that the principal functional sites in the bacterial cell walls were phosphoryl and hydroxyl, carboxyl, amide I, amide II, and amine groups.  相似文献   
998.
Objective: To qualitative and quantitatively review published literature assessing the oxidative stress marker malondialdehyde (MDA) in oral squamous cell carcinoma (OSCC). Methodology: Pubmed (MeSH), Science Direct, Scopus, Web of Science, Willey Online Library, Cochrane, and Cross Reference were searched for studies assessing MDA levels in OSCC samples. Results: From the 1008 articles identified, 849 were excluded based on title and abstract screening due to duplication and irrelevance to the topic of interest. Full-text assessment of the remaining 159 articles led to the inclusion of only 46 articles that satisfied the selection criteria. Of these, only 26 studies had data compatible for quantitative analysis. The MDA levels in OSCC groups are significantly increased (p < 0.00001) in plasma, serum, and saliva samples in the majority of the studies evaluated. In contrast, MDA levels in OSCC tissue samples are significantly attenuated (p < 0.00001) compared to healthy controls, supported by fewer studies. Conclusions: The augmented MDA levels in plasma, serum, and saliva samples of the OSCC reflect the heightened oxidative stress level accurately. Further studies are required to understand the attenuated MDA levels in the tissue samples of OSCC. Correlation analysis between MDA levels with established clinicopathological prognostic markers could aid in formulating oxidative stress-based prognostication and treatment planning.  相似文献   
999.
Transplantations of bone marrow-derived cells (BMDCs) are traditionally used for hematologic diseases, but there are increasing numbers of clinical trials using BMDC treatments for non-hematologic disorders, including autoimmune diseases. BMDCs are recently reported to improve organ functions. This paper will review available reports supporting the role of BMDCs in reducing xerostomia (i.e. re-establishing salivary gland functions) due to head and neck irradiation for cancer therapies and in Sj?gren's syndrome. There are reports that BMDCs provide a beneficial effect on the saliva production. BMDCs positively affect blood vessels stability and regeneration in irradiated salivary glands. Also, BMDCs provide an immunomodulatory activity in mice with Sj?gren's-like disease. While the exact mechanisms by which BMDCs improve organ functions remain controversial, there is preliminary evidence that a combination of them (such as cell transdifferentiation, vasculogenesis, and paracrine effect) occur in salivary glands.  相似文献   
1000.
Acute kidney injury induces the loss of renal microvessels, but the fate of endothelial cells and the mechanism of potential vascular endothelial growth factor (VEGF)-mediated protection is unknown. Cumulative cell proliferation was analyzed in the kidney of Sprague-Dawley rats following ischemia-reperfusion (I/R) injury by repetitive administration of BrdU (twice daily) and colocalization in endothelial cells with CD31 or cablin. Proliferating endothelial cells were undetectable for up to 2 days following I/R and accounted for only ~1% of BrdU-positive cells after 7 days. VEGF-121 preserved vascular loss following I/R but did not affect proliferation of endothelial, perivascular cells or tubular cells. Endothelial mesenchymal transition states were identified by localizing endothelial markers (CD31, cablin, or infused tomato lectin) with the fibroblast marker S100A4. Such structures were prominent within 6 h and sustained for at least 7 days following I/R. A Tie-2-cre transgenic crossed with a yellow fluorescent protein (YFP) reporter mouse was used to trace the fate of endothelial cells and demonstrated interstititial expansion of YFP-positive cells colocalizing with S100A4 and smooth muscle actin following I/R. The interstitial expansion of YFP cells was attenuated by VEGF-121. Multiphoton imaging of transgenic mice revealed the alteration of YFP-positive vascular cells associated with blood vessels characterized by limited perfusion in vivo. Taken together, these data indicate that vascular dropout post-AKI results from endothelial phenotypic transition combined with an impaired regenerative capacity, which may contribute to progressive chronic kidney disease.  相似文献   
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