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61.

Objectives

The aim of the study was to analyze the plasma and urinary cortisol (F) and cortisone (E) levels in normotensive and hypertensive pregnant women. The parameters known to reflect the function of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) were calculated to verify the changes in glucocorticoid balance over the course of gestational hypertension (GH) and pre-eclampsia (PE).

Materials and Methods

This retrospective case-control study included women in the third trimester of pregnancy, diagnosed with: GH (n = 29), PE (n = 26), or chronic hypertension (CH; n = 22). Normotensive women in their third trimester of pregnancy were also included (controls; n = 43). The plasma and urinary F and E levels were measured with the HPLC-FLD method. The 11β-HSD2 function was estimated by calculating the following ratios: plasma F/E and urinary free F to urinary free E (UFF/UFE). A statistical analysis was performed based on case-control structure.

Results and Discussion

PE was characterized by lower plasma F levels (639.0 nmol/L), UFF/Cr levels (3.80 μg/mmol) and F/E ratio (3.46) compared with that of the controls (811.7 nmol/L, 6.28 μg/mmol and 5.19, respectively) with marked abnormalities observed in the changes of F/E and UFF/UFE ratios with advancing gestation. GH patients showed significant disparities in the urinary steroid profile with lower UFF/UFE ratio (0.330 vs. 0.401) compared with the normotensive controls and abnormal changes in the UFF/UFE throughout pregnancy. The observed tendency towards lower F/E and UFF/UFE ratios in PE and GH patients may reflect more intensive F metabolism over the course of those disorders. In the normal pregnancy group, the plasma F/E and UFF/UFE ratios tended to present inverse correlations with advancing gestation. This trend was much less marked in PE and GH patients, suggesting that the abnormalities in 11β-HSD2 functions progressed with the GA. The birth weights of neonates born from pre-eclamptic pregnancies were lower than those from uncomplicated pregnancies, although only when the babies were born prematurely. Children born at term to normotensive mothers or mothers suffering from PE had comparable birth weights.  相似文献   
62.
Herpesviruses are the most prevalent viruses that infect the human and animal body. They can escape a host immune response in numerous ways. One way is to block the TAP complex so that viral peptides, originating from proteasomal degradation, cannot be transported to the endoplasmic reticulum. As a result, a reduced number of MHC class I molecules appear on the surface of infected cells and, thus, the immune system is not efficiently activated. BoHV-1-encoded UL49.5 protein is one such TAP transporter inhibitor. This protein binds to TAP in such a way that its N-terminal fragment interacts with the loops of the TAP complex, and the C-terminus stimulates proteasomal degradation of TAP. Previous studies have indicated certain amino acid residues, especially the RRE(9–11) motif, within the helical structure of the UL49.5 N-terminal fragment, as being crucial to the protein's activity. In this work, we investigated the effects of modifications within the RRE region on the spatial structure of the UL49.5 N-terminal fragment. The introduced RRE(9–11) variations were designed to abolish or stabilize the structure of the α-helix and, consequently, to increase or decrease protein activity compared to the wild type. The terminal structure of the peptides was established using circular dichroism (CD), 2D nuclear magnetic resonance (NMR), and molecular dynamics (MD) in membrane-mimetic or membrane-model environments. Our structural results show that in the RRE(9–11)AAA and E11G peptides the helical structure has been stabilized, whereas for the RRE(9–11)GGG peptide, as expected, the helix structure has partially unfolded compared to the native structure. These RRE modifications, in the context of the entire UL49.5 proteins, slightly altered their biological activity in human cells.  相似文献   
63.
The physiological reasons for the differences in sensitivity of C3 and C4 plant species to environmental stresses have not been thoroughly explained. In this study the effects of drought stress on the growth and selected physiological traits were examined in the seedlings of 13 single cross maize (C4 plant) hybrids and 11 spring triticale (C3 plant) breeding lines and varieties differing in drought sensitivity. For plants in the seedling stage the results demonstrated a genetic variation in dry matter accumulation of shoots and roots (DWS, DWR), number (N) and length (L) of particular components (seminal, seminal adventitious, nodal) of the root system, membrane injury by soil drought (LID), osmotic and high temperature stress (LIOS, LIHT), water potential (ψ), water loss (WL), grain germination in osmotic stress (FG, PI), and seedling survival (SS). Seedlings grown under moderate soil drought showed a decrease in dry matter of the top parts and roots and a decrease in the length of seminal, seminal adventitious and nodal roots in comparison to seedlings grown in control conditions. The observed harmful effects of drought stress were more distinct in drought sensitive genotypes. Used in this paper drought susceptibility indexes (DSIGY) were calculated in other experiment by determining the changes in grain yield (GY) under two soil moisture levels (irrigated and drought). The variation of DSIGY for maize ranges from 0.381 to 0.650 and for triticale from 0.354 to 0.578. The correlations between DSIGY and laboratory tests (LI, FG, SS) confirmed that they are good indicators of drought tolerance in plants. The highest values of genetic variation were observed in LI, DWS, SS and WL and the lowest in the measurements of ψ FG, PI, LS, LSA and LN. The correlation coefficients between LIOS and LIHT tests were, in most of the considered cases, statistically significant, which indicates that in maize and triticale the mechanisms of membrane injury caused by simulated drought or high temperature are physiologically similar. It can be concluded that an approach to the breeding of maize and triticale for drought tolerance using these tests can be implemented on the basis of separate selection for each trait or for all of them simultaneously. In that case, it would be necessary to determine the importance of the trait in relation to growth phase, drought timing and level, as well as its associations with morphological traits contributing to drought tolerance. The obtained values of the correlation coefficient between laboratory tests suggest that the same physiological traits may be applied as selection criteria in drought tolerance of maize and triticale genotypes.  相似文献   
64.
A series of N-{1-[(3-thioxo-5,6-dihydroimidazo[2,1-c][1,2,4]thiadiazol-7-ylthio)thiocarbonyl]-2-imidazolidene}arylsulfonamides (2a-z) was obtained by reacting 6,7-dihydro-1H-imidazo[2,1-c][1,2,4]thiadiazol-3-thione (1) with arylsulfonyl chlorides. The relationships between structure and anti-tumor activity revealed that compound 2o with p-Cl substituent at the phenyl ring was most active (-log GI50>8.00, -log TGI=7.66) and was found to exhibit high selectivity toward the leukemia CCRF-CEM cell line (Deltaf=3.08 and 3.31, respectively).  相似文献   
65.
66.
Five positive carbon isotope excursions are reported from Platteville–Decorah strata in the Upper Mississippi Valley. All occur in subtidal carbonate strata, and are recognized in the Mifflin, Grand Detour, Quimbys Mill, Spechts Ferry, and Guttenberg intervals. The positive carbon isotope excursions are developed in a Platteville–Decorah succession in which background δ13C values increase upward from about −2‰ at the base to about 0‰ Vienna Pee Dee belemnite (VPDB) at the top. A regional north–south δ13C gradient, with lighter values to the north and heavier values to the south is also noted. Peak excursion δ13C values of up to +2.75 are reported from the Quimbys Mill excursion, and up to +2.6 from the Guttenberg excursion, although there are considerable local changes in the magnitudes of these events. The Quimbys Mill, Spechts Ferry, and Guttenberg carbon isotope excursions occur in units that are bounded by submarine disconformities, and completely starve out in deeper, more offshore areas. Closely spaced chemostratigraphic profiles of these sculpted, pyrite-impregnated hardground surfaces show that they are associated with very abrupt centimeter-scale negative δ13C shifts of up to several per mil, possibly resulting from the local diagenetic effects of incursions of euxinic bottom waters during marine flooding events.  相似文献   
67.
HIV-1 integrase (IN) is an essential enzyme for effective viral replication and is an attractive target for selective blockade of viral infection. Previously, we identified a series of sulfones, sulfonamides, and mercaptosalicylhydrazides (MBSAs) as IN inhibitors with antiviral activities in cell-based assays. In an effort to optimize a series of our active site directed lead compounds, we designed and synthesized novel benzodithiazines starting from MBSAs. In contrast to all reported IN inhibitors benzodithiazines are essentially nontoxic. Significant antiviral potency was only observed at concentration exceedingly higher than that required to inhibit purified IN.  相似文献   
68.
Główka FK  Caldwell J 《Chirality》2002,14(9):736-741
The binding of the enantiomers of indobufen (INDB) to human serum proteins was investigated using the racemic mixture or the pure (+)-S-enantiomer in a concentration range of 2.5-100.0 mg/L. In addition, the pharmacokinetics of free (unbound) and total INDB enantiomers were studied 1) following administration of a single 200 mg rac-INDB tablet to healthy volunteers, and 2) in obliterative atherosclerosis patients at steady state. The free fraction of INDB was obtained by ultrafiltration. Using the racemic mixture, the binding parameters of the two enantiomers were different, showing enantioselectivity in protein binding. The (-)-R-enantiomer was bound more strongly to human serum albumin, with association constant K = 11.95 +/- 0.98 x 10(5) M(-1) and n = 0.72 +/- 0.02 binding sites. The comparable data for the (+)-S-enantiomer were K = 4.65 +/- 0.02 x 10(5) M(-1), n = 0.92 +/- 0.01. When the binding of (+)-S-enantiomer was studied alone, the association constant K (2.10 +/- 0.18 x 10(5) M(-1)) was lower and the number of binding sites was increased, to n = 1.87 +/- 0.17. Competition occurred between the enantiomers, with the (-)-R-enantiomer displacing its antipode. The fraction of both enantiomers bound to serum proteins was 99.0%, which increased with decreasing initial concentration of the enantiomers. In healthy volunteers the (+)-S-enantiomer was eliminated faster than its (-)-R antipode, resulting in a lower AUC for the (+)-S-enantiomer. Significant differences were observed in the total INDB enantiomer concentrations. The mean unbound fraction of (-)-R- and (+)-S-INDB was 0.45% and 0.43%, respectively. Levels of the free (+)-S-enantiomer were higher than its (-)-R-antipode at steady state in patients with obliterative atherosclerosis who also took other drugs. The free enantiomer fraction increased to around 1% upon repeated administration. We conclude that the more rapid elimination of the (+)-S enantiomer is associated with its weaker binding to serum proteins.  相似文献   
69.

The valves ofAurikirkbya wordensis (Hamilton, 1942) from the Upper Permian, Word Formation of W Texas (USA), show a crenulated contact groove in the larger valve and smooth contact list in the smaller one. The right valve is usually the larger but occasionally inversion of valves take place. The contact elements of the free margin of valves are discussed in terms of functional morphology. In addition, the muscle-scar areas and the carapace outline have also been regarded. Based on the new discoveries, it is suggested thatA. wordensis was a nectobenthonic filter-feeder. The evidence from the valve interiors is not consistent with a platycopine position for the kirkbyacean taxa.

  相似文献   
70.
The transporter associated with antigen processing (TAP) directly participates in the immune response as a key component of the cytosolic peptide to major histocompatibility complex (MHC) class I protein loading machinery. This makes TAP an important target for viruses avoiding recognition by CD8+ T lymphocytes. Its activity can be suppressed by the UL49.5 protein produced by bovine herpesvirus 1, although the mechanism of this inhibition has not been understood so far.Therefore, the main goal of our study was to investigate the 3D structure of bovine herpesvirus 1 - encoded UL49.5 protein. The final structure of the inhibitor was established using circular dichroism (CD), 2D nuclear magnetic resonance (NMR), and molecular dynamics (MD) in membrane mimetic environments. In NMR studies, UL49.5 was represented by two fragments: the extracellular region (residues 1–35) and the transmembrane-intracellular fragment (residues 36–75), displaying various functions during viral invasion. After the empirical structure determination, a molecular docking procedure was used to predict the complex of UL49.5 with the TAP heterodimer.Our results revealed that UL49.5 adopted a highly flexible membrane-proximal helical structure in the extracellular part. In the transmembrane region, we observed two short α-helices. Furthermore, the cytoplasmic part had an unordered structure. Finally, we propose three different orientations of UL49.5 in the complex with TAP. Our studies provide, for the first time, the experimental structural information on UL49.5 and structure-based insight in its mechanism of action which might be helpful in designing new drugs against viral infections.  相似文献   
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