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81.
R. A. I. Norval C. E. Yunker J. D. Gibson S. L. D. Deem 《Experimental & applied acarology》1988,4(2):173-177
Unfed nymphs ofAmblyomma hebraeum Koch, 1844 shelter under debris on the soil surface and become active in host-seeking when stimulated with carbon dioxide. The active nymphs are not attracted to sources of carbon dioxide and hence cannot be effectively sampled using static carbon dioxide traps. However, these nymphs will cling to flannelette and can be sampled by flagging. Larger numbers are recovered if the soil surface is sampled using a vacuum device. 相似文献
82.
Jessica AB van Nies Celina Alves Audrey LS Radix-Bloemen Cécile Gaujoux-Viala Tom WJ Huizinga Johanna MW Hazes Elisabeth Brouwer Bruno Fautrel Annette HM van der Helm-van Mil 《Arthritis research & therapy》2015,17(1)
IntroductionMorning stiffness is assessed daily in the diagnostic process of arthralgia and arthritis, but large-scale studies on the discriminative ability are absent. This study explored the diagnostic value of morning stiffness in 5,202 arthralgia and arthritis patients and the prognostic value in early rheumatoid arthritis (RA).MethodsIn arthralgia patients referred to the Early Arthritis Recognition Clinics (EARC) of Leiden (n = 807) and Groningen (n = 481) or included in the Rotterdam Early Arthritis Cohort (REACH) study (n = 353), the associations (cross-sectional analyses) between morning stiffness and presence of arthritis at physical examination were studied. In early arthritis patients, included in the Leiden Early Arthritis Clinic (EAC) (n = 2,748) and Evaluation et Suivi de POlyarthrites Indifférenciées Récentes (ESPOIR) (n = 813), associations with fulfilling the 2010-RA criteria after one year were assessed. In 2010-RA patients included in the EAC (n = 1,140) and ESPOIR (n = 677), association with the long-term outcomes of disease-modifying antirheumatic drug (DMARD)-free sustained remission and radiological progression were determined. Morning stiffness was defined as a duration ≥60 minutes; sensitivity analyses were performed for other definitions.ResultsIn arthralgia, morning stiffness (≥60 minutes) associated with the presence of arthritis; Leiden EARC odds ratio (OR) 1.49 (95% CI 1.001 to 2.20), Groningen EARC OR 2.21 (1.33 to 3.69) and REACH OR 1.55 (0.97 to 2.47) but the areas under the receiver operating characteristic curve (AUCs) were low (0.52, 0.57, 0.54). In early arthritis, morning stiffness was associated with 2010-RA independent of other predictors (Leiden EAC OR 1.72 (95% CI 1.31 to 2.25, AUC 0.68), ESPOIR OR 1.68 (1.03 to 2.74, AUC 0.64)). Duration of ≥30 minutes provided optimal discrimination for RA in early arthritis. Morning stiffness was not associated with radiological progression or DMARD-free sustained remission.ConclusionsMorning stiffness in arthralgia and early arthritis is associated with arthritis and RA respectively. This supports the incorporation of morning stiffness in the diagnostic process.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0616-3) contains supplementary material, which is available to authorized users. 相似文献83.
The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment. 相似文献
84.
The evolutionary speed and the consequent immune escape of H3N2 influenza A virus make it an interesting evolutionary system.
Charged amino acid residues are often significant contributors to the free energy of binding for protein–protein interactions,
including antibody–antigen binding and ligand–receptor binding. We used Markov chain theory and maximum likelihood estimation
to model the evolution of the number of charged amino acids on the dominant epitope in the hemagglutinin protein of circulating
H3N2 virus strains. The number of charged amino acids increased in the dominant epitope B of the H3N2 virus since introduction
in humans in 1968. When epitope A became dominant in 1989, the number of charged amino acids increased in epitope A and decreased
in epitope B. Interestingly, the number of charged residues in the dominant epitope of the dominant circulating strain is
never fewer than that in the vaccine strain. We propose these results indicate selective pressure for charged amino acids
that increase the affinity of the virus epitope for water and decrease the affinity for host antibodies. The standard PAM
model of generic protein evolution is unable to capture these trends. The reduced alphabet Markov model (RAMM) model we introduce
captures the increased selective pressure for charged amino acids in the dominant epitope of hemagglutinin of H3N2 influenza
(R
2 > 0.98 between 1968 and 1988). The RAMM model calibrated to historical H3N2 influenza virus evolution in humans fit well
to the H3N2/Wyoming virus evolution data from Guinea pig animal model studies. 相似文献
85.
Johan M. Lorenzen Jan Menne Bernhard MW. Schmidt Mascha Schmidt Filippo Martino Robert Dietrich Senguel Samiri Hans Worthmann Meike Heeren Karin Weissenborn Hermann Haller Mario Schiffer Jan T. Kielstein Thomas Thum 《PloS one》2012,7(10)
Background
In early May 2011, an outbreak of hemorrhagic colitis associated with hemolytic–uremic syndrome (HUS) first developed in Northern Germany and spread to 15 other countries in Europe. The outbreak-strain O104:H4, which combined virulence factors of typical enteroaggregative and Shiga-Toxin–producing E. coli was associated with an unusual high rate of hemolytic uremic syndrome. Also an unexpected high rate of coma and seizures leading to mechanical ventilation and ICU treatment was observed. MicroRNAs are small ribonucleotides orchestrating gene expression. We tested whether circulating microRNAs in serum of HUS patients during the 2011 epidemics are altered in this patient cohort and related to clinical manifestations.Methodology/Principal Findings
We profiled microRNAs using RNA isolated from serum of patients and healthy age-matched controls. The results were validated in 38 patients at baseline, 29 patients during follow-up and 21 age-matched healthy controls by miRNA-specific quantitative RT-PCR. Circulating levels of miR-24, miR-126 were increased in HUS patients versus controls. There was no association between these microRNAs and renal function or the need for renal replacement therapy. In contrast, levels of miR-126 were associated with neurological symptoms at baseline and during follow-up. In addition, miR-126 (on admission) and miR-24 (on admission and during follow-up) were associated with platelet count.Conclusions/Significance
Circulating microRNAs are strongly altered in this patient cohort and associated with neurological symptoms as well as platelet count. 相似文献86.
Rogier AM Quax Ya?l A de Man Jan W Koper Elisabeth FC van Rossum Sten P Willemsen Steven WJ Lamberts Johanna MW Hazes Radboud JEM Dolhain Richard A Feelders 《Arthritis research & therapy》2012,14(4):R183
Introduction
The mechanism underlying the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and the subsequent postpartum flare is incompletely understood, and the disease course varies widely between pregnant RA patients. In pregnancy, total and free levels of cortisol increase gradually, followed by a postpartum decrease to prepregnancy values. The glucocorticoid receptor (GR) polymorphisms BclI and N363S are associated with relatively increased glucocorticoid (GC) sensitivity, whereas the 9β and ER22/23EK polymorphisms of the GR gene are associated with a relatively decreased GC sensitivity. We examined the relation between the presence of these GR polymorphisms and level of disease activity and disease course of RA during pregnancy and postpartum.Methods
We studied 147 participants of the PARA study (Pregnancy-Induced Amelioration of Rheumatoid Arthritis study), a prospective study investigating the natural improvement during pregnancy and the postpartum flare in women with RA. Patients were visited, preferably before pregnancy, at each trimester and at three postpartum time points. On all occasions, disease activity was scored by using DAS28. All patients were genotyped for the GR polymorphisms BclI, N363S, 9β, and ER22/23EK and divided in groups harboring either polymorphisms conferring increased GC sensitivity (BclI and N363S; GC-S patients) or polymorphisms conferring decreased GC sensitivity (9β or 9β + ER22/23EK; GC-I patients). Data were analyzed by using a mixed linear model, comparing GC-S patients with GC-I patients with respect to improvement during pregnancy and the postpartum flare. The cumulative disease activity was calculated by using time-integrated values (area under the curve, AUC) of DAS28 in GC-I patients versus GC-S patients. Separate analyses were performed according to the state of GC use.Results
GC-S patients treated with GC had a significantly lower AUC of DAS28 in the postpartum period than did GC-I patients. This difference was not observed in patients who were not treated with GCs. During pregnancy, GC-S and GC-I patients had comparable levels of disease activity and course of disease.Conclusions
Differences in relative GC sensitivity, as determined by GR polymorphisms, are associated with the level of disease activity in the postpartum period in GC-treated patients, but they do not seem to influence the course of the disease per se. 相似文献87.
Epigenetic regulation of genomic integrity 总被引:1,自引:0,他引:1
Inefficient and inaccurate repair of DNA damage is the principal cause of DNA mutations, chromosomal aberrations, and carcinogenesis.
Numerous multiple-step DNA repair pathways exist whose deployment depends on the nature of the DNA lesion. Common to all eukaryotic
DNA repair pathways is the need to unravel the compacted chromatin structure to facilitate access of the repair machinery
to the DNA and restoration of the original chromatin state afterward. Accordingly, our cells utilize a plethora of coordinated
mechanisms to locally open up the chromatin structure to reveal the underlying DNA sequence and to orchestrate the efficient
and accurate repair of DNA lesions. Here we review changes to the chromatin structure that are intrinsic to the DNA damage
response and the available mechanistic insight into how these chromatin changes facilitate distinct stages of the DNA damage
repair pathways to maintain genomic stability. 相似文献
88.
Gennady V. Pogorelko Parijat S. Juvale William B. Rutter Marion Hütten Thomas R. Maier Tarek Hewezi Judith Paulus Renier AL van der Hoorn Florian MW Grundler Shahid Siddique Vincenzo Lionetti Olga A. Zabotina Thomas J. Baum 《The Plant journal : for cell and molecular biology》2019,98(6):1000-1014
Plants mount defense responses during pathogen attacks, and robust host defense suppression by pathogen effector proteins is essential for infection success. 4E02 is an effector of the sugar beet cyst nematode Heterodera schachtii. Arabidopsis thaliana lines expressing the effector‐coding sequence showed altered expression levels of defense response genes, as well as higher susceptibility to both the biotroph H. schachtii and the necrotroph Botrytis cinerea, indicating a potential suppression of defenses by 4E02. Yeast two‐hybrid analyses showed that 4E02 targets A. thaliana vacuolar papain‐like cysteine protease (PLCP) ‘Responsive to Dehydration 21A’ (RD21A), which has been shown to function in the plant defense response. Activity‐based protein profiling analyses documented that the in planta presence of 4E02 does not impede enzymatic activity of RD21A. Instead, 4E02 mediates a re‐localization of this protease from the vacuole to the nucleus and cytoplasm, which is likely to prevent the protease from performing its defense function and at the same time, brings it in contact with novel substrates. Yeast two‐hybrid analyses showed that RD21A interacts with multiple host proteins including enzymes involved in defense responses as well as carbohydrate metabolism. In support of a role in carbohydrate metabolism of RD21A after its effector‐mediated re‐localization, we observed cell wall compositional changes in 4E02 expressing A. thaliana lines. Collectively, our study shows that 4E02 removes RD21A from its defense‐inducing pathway and repurposes this enzyme by targeting the active protease to different cell compartments. 相似文献
89.
90.
Y chromosome variation of mice and men 总被引:7,自引:5,他引:2
DNA sequences from the nonrecombining portion of the Y chromosome were
compared with autosomal and X-linked sequences from mice and humans to test
the neutral prediction that ratios of polymorphism to divergence are the
same for different genes. Intraspecific variation within Mus domesticus was
compared with divergence between M. domesticus and Mus caroli for Sry, a
region 5' to Sry, and four X-linked genes, Hprt, Plp, Amg, and Glra2. None
of these comparisons revealed significantly reduced variation on the Y
chromosome. Intraspecific variation within humans was compared with
divergence between humans and chimpanzees for three Y-linked loci (Zfy, the
YAP region, and the Sry region), seven X- linked loci (Il2rg, Plp, Hprt,
Gk, Ids, Pdhal, and Dmd), and the beta- globin locus on chromosome 11. In
these comparisons, the observed level of variation on the human Y
chromosome was slightly lower than expected, but was significantly lower in
only one case (Sry region vs. Dmd). These results suggest that the levels
of variability on the Y chromosome in mice and humans are close to expected
values given the effective population size and mutation rates for these
loci. There is at most only a modest reduction in variability that may be
attributed to natural selection (either genetic hitchhiking or background
selection).
相似文献