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81.
Introduction Mental disorders occur as frequently in Russia as elsewhere, but the common mental disorders, especially depression, have gone largely unrecognised and undiagnosed by policlinic staff and area doctors.Methods This paper describes the impact and sustainability of a multi-component programme to facilitate the integration of mental health into primary care, by situation appraisal, policy dialogue, development of educational materials, provision of a training programme and the publication of standards and good practice guidelines to improve the primary care of mental disorders in the Sverdlovsk region of the Russian Federation.Results The multi-component programme has resulted in sustainable training about common mental disorders, not only of family doctors but also of other cadres and levels of professionals, and it has been well integrated with Sverdlovsk's overall programme of health sector reforms.Conclusion It is possible to facilitate the sustainable integration of mental health into primary care within the Russian context. While careful adaptation will be needed, the approach adopted here may also hold useful lessons for policy makers seeking to integrate mental health within primary care in other contexts and settings.  相似文献   
82.
83.
The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O12. Its structure was studied by sugar analysis using GLC of the alditol acetates and (S)-2-octyl glycosides, methylation analysis, Smith degradation, and 1H and 13C NMR spectroscopy, including 2D 1H-1H COSY, TOCSY, ROESY, 1H-13C HSQC, and HMBC experiments. It was found that the polymer is a neutral heteropolysaccharide and has a branched heptasaccharide repeating unit with the following structure:  相似文献   
84.
B lymphocytes are essential antibody-producing cells of the immune system. During the development of progenitor B cells to mature B cells that express a membrane-bound antibody, the B cell receptor (BCR), the cells undergo selection at several checkpoints, which ensures that a diverse antibody repertoire is generated and that the BCRs recognise foreign-, but not self-, antigens. In this review, we consider the pre-BCR checkpoint. Mutations or alterations that affect this checkpoint underpin the development of pre-B cell leukemias, primary immunodeficiency, and possibly, systemic autoimmunity.  相似文献   
85.
Mutations in the receptor-binding site of the hemagglutinin of pandemic influenza A(H1N1) 2009 viruses have been detected sporadically. An Asp222Gly (D222G) substitution has been associated with severe or fatal disease. Here we show that 222G variants infected a higher proportion of ciliated cells in cultures of human airway epithelium than did viruses with 222D or 222E, which targeted mainly nonciliated cells. Carbohydrate microarray analyses showed that 222G variants bind a broader range of α2-3-linked sialyl receptor sequences of a type expressed on ciliated bronchial epithelial cells and on epithelia within the lung. These features of 222G mutants may contribute to exacerbation of disease.Although the majority of disease cases have been mild, the pandemic influenza A(H1N1) 2009 (H1N1pdm) virus has caused a substantial number of severe and fatal infections (2). Mutants with a D222G or D222E substitution (D225G or D225E in the H3 numbering system) in the receptor-binding site of the virus hemagglutinin (HA) have been detected sporadically (1), and the D222G substitution has been observed to correlate with cases of severe or fatal disease (1, 3, 9, 14). Cell surface receptors for influenza viruses are sialyl glycans (α2-3 Sia or α2-6 Sia) with terminal sialic acid linked α2-3 or α2-6, respectively, to a penultimate galactose. These differ in distribution in the tissues and cells of different species. The sialyl glycans are differentially recognized by the HAs of human and animal influenza viruses and are critical determinants of host range and tissue tropism (16). Using an experimental system of differentiated cultures of human tracheobronchial epithelial cells (HTBE) for studying influenza virus cell tropism, we and others have established that in the initial stages of infection, seasonal human influenza viruses which recognize α2-6 Sia receptors infect mainly nonciliated cells, whereas avian viruses which recognize α2-3 Sia receptors predominantly infect ciliated cells (8, 17, 22).Previous analyses of human and swine influenza H1N1 viruses (5, 15, 21) and preliminary studies of H1N1pdm viruses (24) have indicated that amino acid substitutions in the HA at position 222 may affect the specificity of receptor binding. This, in turn, would be predicted to determine the range of cell types in human respiratory tissues infected by the viruses (17, 20, 22, 23). We have therefore examined the influence of the D222G and D222E substitutions on the cell tropism of H1N1pdm viruses in HTBE cultures (Table (Table1).1). Five viruses were isolated from clinical material in MDCK cells and passaged solely in these cells. Two of these, A/Hamburg/5/2009 (Ham) (4) isolated from a case of mild infection and A/Moldova/G186/2009 (Mol) from a serious but nonfatal infection, had 222D. A/Dakar/37/2009 (Dak) isolated from a mild case of the disease had 222E. Two isolates from fatal cases, A/Lviv/N6/2009 (Lvi) and A/Norway/3206-3/2009 (Nor), had 222G. A sixth virus tested, A/Hamburg/5/2009-e (Ham-e), was derived from Ham by egg passage and plaque purification in MDCK cells and differed by a single substitution, D222G.

TABLE 1.

Differences in amino acid sequence of the HAs of the H1N1pdm viruses and cell tropism in HTBE cultures
VirusOutcomeSubstitution at HA position:a
Infected ciliated cellsb
137 (140)154 (157)155 (158)203 (206)222 (225)
A/Moldova/G186/2009 (Mol)NonfatalPKGTD4.7 (2.2)
A/Dakar/37/2009 (Dak)NonfatalE2.7 (1.8)
A/Hamburg/5/2009 (Ham)NonfatalS3.3 (2.1)
A/Hamburg/5/2009-e (Ham-e)SG25 (12)d
A/Norway/3206-3/2009 (Nor)FatalSEcG19 (6.7)d
A/Lviv/N6/2009 (Lvi)FatalEcG34 (15)d
Open in a separate windowaAmino acids differing from those of Moldova/G186/2009 are shown. H3 numbering is in parentheses.bThe percentage of infected ciliated cells relative to the total number of infected cells. Standard deviations are shown in parentheses.cSubstitution acquired during isolation and propagation in MDCK cells.dP < 0.0001 (unpaired two-sided t test versus A/Moldova/G186/2009).The preparation of differentiated HTBE cultures, viral infection of the cultures for cell tropism analysis, and double immunostaining for viral antigen and cilia of ciliated cells were done as described previously (17). Infected cells were counted in the epithelial segment that included 15 to 30 consecutive microscopic fields containing between 5 and 20% ciliated cells relative to the total number of superficial cells. Percentages of infected ciliated cells relative to the total number of infected cells were calculated for each segment. Ten segments per culture were analyzed, and the results were averaged.Two distinctive patterns of cell tropism were observed (Fig. (Fig.11 and Table Table1).1). The viruses with 222D (Mol and Ham) and 222E (Dak) showed a pattern of cell tropism typical of seasonal influenza A and B viruses (17, 22) infecting predominantly nonciliated cells known to be rich in α2-6 Sia sequences (17): less than 5% of infected cells were ciliated. In contrast, the three viruses with 222G, Lvi, Nor, and Ham-e, infected both ciliated and nonciliated cells, and 20% or more of the infected cells were ciliated and known to express α2-3 Sia sequences (11, 17). This change in cell tropism, with a 5- to 10-fold increase in the infection of ciliated cells, thus correlated with the presence of the D222G substitution in the HA, and other amino acid differences, in particular D222E, had little or no effect. Furthermore, there were no differences between the amino acid sequences of the neuraminidases (NA) of the 222D, 222G, and 222E viruses which might have an impact on cell tropism: the NA sequences of Mol, Nor, Lvi, and Dak were identical.Open in a separate windowFIG. 1.Difference in cell tropism between the clinical isolate Ham (left image) and its 222G variant Ham-e (right image) in HTBE cultures. The cultures were infected at a multiplicity of infection of approximately 1, fixed 8 h after infection, and double immunostained for virus antigen using rabbit antisera against A/California/4/2009(H1N1pdm) (red) and for cilia of ciliated cells using an anti-β tubulin monoclonal antibody (dark gray). Arrowheads point to infected ciliated cells. Bars, 10 μm.To investigate whether changes in receptor binding specificity could account for the distinct cell tropism of the 222G variants, we performed carbohydrate microarray analyses (Fig. (Fig.22 and Table Table2;2; see Fig. S1 and S2 and Table S1 in the supplemental material). The virus preparations were analyzed in the absence of or following inactivation by treatment with beta-propiolactone; the conditions used (4) had no perceptible effect on the receptor-binding profiles. Virus suspensions were concentrated by pelleting, adjusted to contain equivalent concentrations of viruses as assessed by HA titration with human red blood cells and gel electrophoresis with immunoblotting, and stored at 4°C in phosphate-buffered saline (pH 7.4) containing 0.05% sodium azide. The microarray analyses were performed as described previously (4) using the same array series of lipid-linked probes (see Table S1 in the supplemental material). Unless stated otherwise, the viruses were analyzed at an HA titer of 2,000.Open in a separate windowFIG. 2.Carbohydrate microarray analyses of H1N1pdm viruses. The microarray data are for the two 222D viruses (Mol and Ham), the 222E mutant virus (Dak), and the three 222G mutant viruses (Nor, Lvi, and Ham-e) analyzed at an HA titer of 2,000. The microarrays consisted of 80 sialylated and 6 neutral lipid-linked glycan probes arranged according to sialic acid linkage, glycan backbone chain length, and sequence (see Table S1 in the supplemental material). The numerical scores for the fluorescent binding signals are means (with error bars) for duplicate spots at 5 fmol/spot. The various types of terminal sialic acid linkage are indicated by the colored panels as defined at the bottom.

TABLE 2.

Virus binding of selected α2-3 Sia sequences in carbohydrate microarrays grouped according to backbone sequence and lipid moiety
Open in a separate window
Open in a separate windowa Probe number and position in microarrays.b Abbreviations for monosaccharides: Fuc, fucose; Gal, galactose; Glc, glucose; GlcNAc, N-acetylglucosamine; NeuAc, N-acetylneuraminic acid. Other abbreviations: Cer, natural glycolipids with various ceramide moieties; Cer36, synthetic glycolipids with ceramide having a total of 36 carbon atoms; DH, neoglycolipids prepared from reducing oligosaccharides by reductive amination with the amino lipid 1,2-dihexadecyl-sn-glycero-3-phosphoethanolamine.c —, Signal intensity of <500.For all of the viruses, the intensities of binding to α2-6 Sia sequences were greater overall than the intensities of binding to the α2-3 Sia sequences. There were, however, marked differences between the two 222D viruses, Mol and Ham, and the three 222G variants, Lvi, Nor, and Ham-e, in binding to the α2-3 Sia sequences (highlights are in Table Table2).2). With the 222D viruses, relatively low intensities of binding to α2-3 Sia sequences were detected and they bound mostly to α2-3 Sia sequences that were modified with fucose (Fuc) on the outer N-acetylglucosamine (GlcNAc), as in the blood group-related antigens sialyl Lewisa (SLea) and SLex (probes 28, 29, and 31) and/or with sulfate (SU) on GlcNAc (probes 27 and 35, Table Table2;2; see Fig. S2b in the supplemental material). This is in accord with our previous study of Ham (see Fig. S3 in the supplemental material for reference 4). In contrast, the 222G mutants not only bound more strongly to these α2-3 Sia sequences but bound to additional sequences, such as the VIM-2 antigen sequence (probe 39) with Fuc on internal GlcNAc and to sequences lacking Fuc or SU (probes 23 and 24, Table Table2;2; see Fig. S2a in the supplemental material). All of the pdm viruses investigated here showed greater binding to the 6SU-SLex sequence (probe 35) than to the analogue lacking SU (probe 31) and 6′SU SLex (probe 33, Table Table2).2). This is a property shared with highly pathogenic poultry viruses (6, 7). The pattern of binding to the α2-6 Sia sequences was largely unchanged (Fig. (Fig.2;2; see Fig. S2c in the supplemental material).As passage in MDCK cells tends to select “complementary” amino acid changes such as K154E or G155E in addition to the single D222G mutation present in the virus of the clinical specimen, two more viruses were investigated as controls for the effects of this substitution in Lvi, the double mutant (G155E D222G). These were A/Athens/16606/2009 (Ath) and A/Lisbon/120/2009 (Lis), which possess the G155E substitution in the absence of D222G. The binding profiles observed for Ath and Lis (see Fig. S3 in the supplemental material) indicated that the 155 substitution did not contribute to the increased α2-3 Sia binding of Lvi, which was therefore due exclusively to the D222G substitution.The D222E mutant Dak exhibited a carbohydrate-binding profile that was intermediate between those of the 222D and 222G viruses. Compared to the 222D viruses (Mol and Ham) that targeted preferentially nonciliated cells, Dak displayed slightly increased binding to some α2-3 Sia sequences. It was clearly distinguishable from the 222G variants by weaker or negligible binding to a number of other α2-3 Sia sequences, for example, probes 24 and 33 and the VIM-2 antigen sequence, probe 39 (Fig. (Fig.22 and Table Table2;2; see Fig. S1 and S2 in the supplemental material). These are properties that Dak shared with 222D viruses. The similarities in receptor binding and cell tropism of the 222E and 222D viruses are consistent with their circulation in the population, in contrast to the 222G variants that have emerged sporadically and do not appear to be transmitted readily to other individuals (18).There is thus a clear correlation between enhanced binding to α2-3 Sia sequences by the 222G variants and increased infection of ciliated epithelial cells. The increased capacity of 222G mutant viruses to infect ciliated epithelial cells prominent along the entire airway epithelium would be predicted to interfere with the important mucociliary clearance function of these cells and increase the severity of disease. Another human pathogen, Mycoplasma pneumoniae, which can also cause severe respiratory disease targets the microvilli of ciliated cells in the human bronchus (10) that express the VIM-2 antigen (12, 13). The enhanced capacity of the 222G variants to target α2-3 Sia receptors present in relatively larger amounts on ciliated epithelial cells of the tracheobronchial epithelium (11, 17) and on cells in bronchioles and alveoli (20) may also contribute to more severe pulmonary infection, as suggested by the more frequent identification of 222G variants in specimens from the lower respiratory tract (3), and may explain why they are infrequently transmitted. It is also pertinent to note that the D222G substitution was identified in the HAs from two of five victims of the 1918 pandemic (19). Glycan array analyses of recombinant HAs from one of the 1918 222G mutant viruses (A/New York/1/18) showed (21) a narrow profile of binding to certain α2-3 Sia sequences which had an additional negative charge such as SU or sialic acid. The pattern was more restricted than the repertoire of α2-3 Sia sequences bound by the 222G 2009 pdm viruses that we have investigated here. The New York variant showed little binding to α2-6 Sia sequences, in contrast to the strong and broad α2-6 Sia binding profiles of the 2009 pdm viruses observed here and in an earlier study (24). These differences between the 1918 and 2009 pdm viruses are most likely a reflection of differences in other residues in the receptor-binding pocket.Whether the selection of the D222G mutation is a cause or a consequence of more severe lower respiratory tract infection is still to be resolved. It is evident, however, that its emergence is likely to exacerbate the severity of disease. The altered receptor specificity and distinctive cell tropism of the D222G mutants of H1N1pdm are hallmarks of a more dangerous pathogen, emphasizing the importance of close monitoring of the evolution of these viruses.   相似文献   
86.
Various NGR-containing peptides have been exploited for targeted delivery of drugs to CD13-positive tumor neovasculature. Recent studies have shown that compounds containing this motif can rapidly deamidate and generate isoaspartate-glycine-arginine (isoDGR), a ligand of αvβ3-integrin that can be also exploited for drug delivery to tumors. We have investigated the role of NGR and isoDGR peptide scaffolds on their biochemical and biological properties. Peptides containing the cyclic CNGRC sequence could bind CD13-positive endothelial cells more efficiently than those containing linear GNGRG. Peptide degradation studies showed that cyclic peptides mostly undergo NGR-to-isoDGR transition and CD13/integrin switching, whereas linear peptides mainly undergo degradation reactions involving the α-amino group, which generate non-functional six/seven-membered ring compounds, unable to bind αvβ3, and small amount of isoDGR. Structure-activity studies showed that cyclic isoDGR could bind αvβ3 with an affinity >100-fold higher than that of linear isoDGR and inhibited endothelial cell adhesion and tumor growth more efficiently. Cyclic isoDGR could also bind other integrins (αvβ5, αvβ6, αvβ8, and α5β1), although with 10–100-fold lower affinity. Peptide linearization caused loss of affinity for all integrins and loss of specificity, whereas α-amino group acetylation increased the affinity for all tested integrins, but caused loss of specificity. These results highlight the critical role of molecular scaffold on the biological properties of NGR/isoDGR peptides. These findings may have important implications for the design and development of anticancer drugs or tumor neovasculature-imaging compounds, and for the potential function of different NGR/isoDGR sites in natural proteins.  相似文献   
87.
Numerous intracellular pathogens exploit cell surface glycoconjugates for host cell recognition and entry. Unlike bacteria and viruses, Toxoplasma gondii and other parasites of the phylum Apicomplexa actively invade host cells, and this process critically depends on adhesins (microneme proteins) released onto the parasite surface from intracellular organelles called micronemes (MIC). The microneme adhesive repeat (MAR) domain of T. gondii MIC1 (TgMIC1) recognizes sialic acid (Sia), a key determinant on the host cell surface for invasion by this pathogen. By complementation and invasion assays, we demonstrate that TgMIC1 is one important player in Sia-dependent invasion and that another novel Sia-binding lectin, designated TgMIC13, is also involved. Using BLAST searches, we identify a family of MAR-containing proteins in enteroparasitic coccidians, a subclass of apicomplexans, including T. gondii, suggesting that all these parasites exploit sialylated glycoconjugates on host cells as determinants for enteric invasion. Furthermore, this protein family might provide a basis for the broad host cell range observed for coccidians that form tissue cysts during chronic infection. Carbohydrate microarray analyses, corroborated by structural considerations, show that TgMIC13, TgMIC1, and its homologue Neospora caninum MIC1 (NcMIC1) share a preference for α2–3- over α2–6-linked sialyl-N-acetyllactosamine sequences. However, the three lectins also display differences in binding preferences. Intense binding of TgMIC13 to α2–9-linked disialyl sequence reported on embryonal cells and relatively strong binding to 4-O-acetylated-Sia found on gut epithelium and binding of NcMIC1 to 6′sulfo-sialyl Lewisx might have implications for tissue tropism.  相似文献   
88.
Signaling cascades that control adipogenesis are essential in the regulation of body weight and obesity. The adaptor p62 controls pathways that modulate cell differentiation. We report here that p62(-/-) mice develop mature-onset obesity, leptin resistance, as well as impaired glucose and insulin intolerance. The metabolic rate was significantly reduced in p62(-/-) nonobese mice, which displayed increased mRNA levels of PPAR-gamma and reduced levels of UCP-1 in adipose tissue. Basal activity of ERK was enhanced in fat from nonobese mutant mice. Embryo fibroblasts from p62(-/-) mice differentiated better than the wild-type controls into adipocytes, which was abrogated by pharmacological inhibition of the ERK pathway. p62 is induced during adipocyte differentiation and inhibits ERK activation by direct interaction. We propose that p62 normally antagonizes basal ERK activity and adipocyte differentiation and that its loss leads to the hyperactivation of ERK that favors adipogenesis and obesity.  相似文献   
89.
90.
Microarray analysis is a critically important technology for genome-enabled biology, therefore it is essential that the data obtained be reliable. Current software and normalization techniques for microarray analysis rely on the assumption that fluorescent background within spots is essentially the same throughout the glass slide and can be measured by fluorescence surrounding the spots. This assumption is not valid if background fluorescence is spot-localized. Inaccurate estimates of background fluorescence under the spot create a source of error, especially for low expressed genes. We have identified spot-localized, contaminating fluorescence in the Cy3 channel on several commercial and in-house printed microarray slides. We determined through mock hybridizations (without labeled target) that pre-hybridization scans could not be used to predict the contribution of this contaminating fluorescence after hybridization because the change in spot-to-spot fluorescence after hybridization was too variable. Two solutions to this problem were identified. First, allowing 4 h of exposure to air prior to printing on to Corning UltraGAPS slides significantly reduced contaminating fluorescence intensities to approximately the value of the surrounding glass. Alternatively, application of a novel, hyperspectral imaging scanner and multivariate curve resolution algorithms, allowed the spectral contributions of Cy3 signal, glass, and contaminating fluorescence to be distinguished and quantified after hybridization.  相似文献   
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