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排序方式: 共有111条查询结果,搜索用时 15 毫秒
81.
D Gloag 《BMJ (Clinical research ed.)》1985,290(6471):834-836
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Oscar Rosas Mejia Erin S. Gloag Jianying Li Marisa Ruane-Foster Tiffany A. Claeys Daniela Farkas Shu-Hua Wang Laszlo Farkas Gang Xin Richard T. Robinson 《PLoS pathogens》2022,18(3)
Mycobacterium tuberculosis (Mtb) and SARS-CoV-2 (CoV2) are the leading causes of death due to infectious disease. Although Mtb and CoV2 both cause serious and sometimes fatal respiratory infections, the effect of Mtb infection and its associated immune response on secondary infection with CoV2 is unknown. To address this question we applied two mouse models of COVID19, using mice which were chronically infected with Mtb. In both model systems, Mtb-infected mice were resistant to the pathological consequences of secondary CoV2 infection, and CoV2 infection did not affect Mtb burdens. Single cell RNA sequencing of coinfected and monoinfected lungs demonstrated the resistance of Mtb-infected mice is associated with expansion of T and B cell subsets upon viral challenge. Collectively, these data demonstrate that Mtb infection conditions the lung environment in a manner that is not conducive to CoV2 survival. 相似文献
84.
Daphne Gloag 《BMJ (Clinical research ed.)》1978,2(6151):1547-1548
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RS Redman GS Kerr JB Payne TR Mikuls J Huang HR Sayles 《Biotechnic & histochemistry》2016,91(2):77-85
Serum procalcitonin (ProCT) is elevated in response to bacterial infections, whereas high sensitivity C-reactive protein (hsCRP) is a nonspecific inflammatory marker that is increased by excess adipose tissue. We examined the efficacy of ProCT and hsCRP as biomarkers of periodontitis in the saliva and serum of patients with arthritis, which is characterized by variable levels of systemic inflammation that potentially can confound the interpretation of inflammatory biomarkers. Blood and unstimulated whole saliva were collected from 33 patients with rheumatoid arthritis (RA) and 50 with osteoarthritis (OA). Periodontal status was assessed by full mouth examination and patients were categorized as having no/mild, moderate or severe periodontitis by standard parameters. Salivary and serum ProCT and hsCRP concentrations were compared. BMI, diabetes, anti-inflammatory medications and smoking status were ascertained from the patient records. Differences between OA and RA in proportionate numbers of patients were compared for race, gender, diabetes, adiposity and smoking status. Serum ProCT was significantly higher in arthritis patients with moderate to severe and severe periodontitis compared with no/mild periodontitis patients. There were no significant differences in salivary ProCT or salivary or serum hsCRP in RA patients related to periodontitis category. Most of the OA and RA patients were middle aged or older, 28.9% were diabetic, 78.3% were overweight or obese, and slightly more than half were either current or past smokers. The OA and RA groups differed by race, but not gender; blacks and males were predominant in both groups. The OA and RA groups did not differ in terms of controlled or uncontrolled diabetes, smoking status or BMI. The RA patients had been prescribed more anti-inflammatory medication than the OA patients. Our results demonstrate that circulating ProCT is a more discriminative biomarker for periodontitis than serum hsCRP in patients with underlying arthritis. Any elevation in salivary and serum hsCRP due to periodontitis apparently was overshadowed by differences among these patients in factors that influence CRP, such as the extent of inflammation between RA and OA, the extent of adipose tissue, the use of anti- inflammatory medications and smoking status. Although our study showed no differences in salivary ProCT related to severity of periodontitis, this biomarker also may be useful with further refinement. 相似文献
87.
Rosalyn S. Gloag Joshua R. Christie Guiling Ding Ruby E. Stephens Gabriele Buchmann Benjamin P. Oldroyd 《Molecular ecology》2019,28(7):1585-1592
The hallmark of eusociality is the division of labour between reproductive (queen) and nonreproductive (worker) females. Yet in many eusocial insects, workers retain the ability to produce haploid male offspring from unfertilized eggs. The reproductive potential of workers has well‐documented consequences for the structure and function of insect colonies, but its implications at the population level are less often considered. We show that worker reproduction in honey bees can have an important role in maintaining genetic diversity at the sex locus in invasive populations. The honey bee sex locus is homozygous‐lethal, and, all else being equal, a higher allele number in the population lead to higher mean brood survival. In an invasive population of the honey bee Apis cerana in Australia, workers contribute significantly to male production: 38% of male‐producing colonies are queenless, and these contribute one‐third of all males at mating congregations. Using a model, we show that such male production by queenless workers will increase the number of sex alleles retained in nascent invasive populations following founder events, relative to a scenario in which only queens reproduce. We conclude that by rescuing sex locus diversity that would otherwise be lost, workers' sons help honey bee populations to minimize the negative effects of inbreeding after founder events and so contribute to their success as invaders. 相似文献
88.
Sara S Roscioni Loes EM Kistemaker Mark H Menzen Carolina RS Elzinga Reinoud Gosens Andrew J Halayko Herman Meurs Martina Schmidt 《Respiratory research》2009,10(1):1-17
Background
Platelet-derived growth factor A (PDGF-A) signals solely through PDGF-Rα, and is required for fibroblast proliferation and transdifferentiation (fibroblast to myofibroblast conversion) during alveolar development, because pdgfa-null mice lack both myofibroblasts and alveoli. However, these PDGF-A-mediated mechanisms remain incompletely defined. At postnatal days 4 and 12 (P4 and P12), using mouse lung fibroblasts, we examined (a) how PDGF-Rα correlates with ki67 (proliferation marker) or alpha-smooth muscle actin (αSMA, myofibroblast marker) expression, and (b) whether PDGF-A directly affects αSMA or modifies stimulation by transforming growth factor beta (TGFβ).Methods
Using flow cytometry we examined PDGF-Rα, αSMA and Ki67 in mice which express green fluorescent protein (GFP) as a marker for PDGF-Rα expression. Using real-time RT-PCR we quantified αSMA mRNA in cultured Mlg neonatal mouse lung fibroblasts after treatment with PDGF-A, and/or TGFβ.Results
The intensity of GFP-fluorescence enabled us to distinguish three groups of fibroblasts which exhibited absent, lower, or higher levels of PDGF-Rα. At P4, more of the higher than lower PDGF-Rα + fibroblasts contained Ki67 (Ki67+), and Ki67+ fibroblasts predominated in the αSMA + but not the αSMA- population. By P12, Ki67+ fibroblasts comprised a minority in both the PDGF-Rα + and αSMA+ populations. At P4, most Ki67+ fibroblasts were PDGF-Rα + and αSMA- whereas at P12, most Ki67+ fibroblasts were PDGF-Rα- and αSMA-. More of the PDGF-Rα + than - fibroblasts contained αSMA at both P4 and P12. In the lung, proximate αSMA was more abundant around nuclei in cells expressing high than low levels of PDGF-Rα at both P4 and P12. Nuclear SMAD 2/3 declined from P4 to P12 in PDGF-Rα-, but not in PDGF-Rα + cells. In Mlg fibroblasts, αSMA mRNA increased after exposure to TGFβ, but declined after treatment with PDGF-A.Conclusion
During both septal eruption (P4) and elongation (P12), alveolar PDGF-Rα may enhance the propensity of fibroblasts to transdifferentiate rather than directly stimulate αSMA, which preferentially localizes to non-proliferating fibroblasts. In accordance, PDGF-Rα more dominantly influences fibroblast proliferation at P4 than at P12. In the lung, TGFβ may overshadow the antagonistic effects of PDGF-A/PDGF-Rα signaling, enhancing αSMA-abundance in PDGF-Rα-expressing fibroblasts. 相似文献89.
Phylogenetic analysis of the 90 kD heat shock family of protein sequences and an examination of the relationship among animals, plants, and fungi species 总被引:17,自引:1,他引:16
The heat shock protein (Hsp) sequences, because of their ubiquity and high
degree of conservation, provide useful models for phylogenetic analysis. In
this paper I have carried out a global alignment of all available sequences
(a total of 31) for the 90-kD heat shock protein (Hsp90) family. The
minimum amino acid identity that is seen between presently known Hsp90
homologs is about 40% over the entire length, indicating that it is a
highly conserved protein. Based on the alignment, a number of signature
sequences that either are distinctive of the Hsp90 family or that
distinguish between the cytosolic and the endoplasmic reticular forms of
Hsp90 have been identified. Detailed phylogenetic analyses based on Hsp90
sequences reported here strongly indicate that the cytosolic and the
endoplasmic reticulum (ER) resident forms of Hsp90 constitute paralogous
gene families which arose by a gene duplication event that took place very
early in the evolution of eukaryotic cells. A minimum of two additional
gene duplication events, which took place at a later time, are required to
explain the presence of two different forms of Hsp90 that are found in
fungi and vertebrate species. In a consensus neighbor-joining bootstrap
tree based on Hsp90 sequences, plants and animals species grouped together
989 times of 1,000 (a highly significant score), indicating a closer
relationship between them as compared to fungi. A closer affiliation of
plant and animal species was also observed in the maximum-parsimony tree,
although the relationship was not significantly supported by this method. A
survey of the recent literature on this subject indicates that depending on
the protein sequence and the methods of phylogenetic analysis, the animal
species are indicated as closer relatives to either plants or fungi with
significant statistical support for both topologies. Thus the relationship
among the animal, plant, and fungi kingdoms remains an unresolved issue at
the present time.
相似文献
90.
The phylogenetic position of the archaebacteria and the place of eukaryotes
in the history of life remain a question of debate. Recent studies based on
some protein-sequence data have obtained unusual phylogenies for these
organisms. We therefore collected the protein sequences that were available
with representatives from each of the major forms of life: the
gram-negative bacteria, gram-positive bacteria, archaebacteria, and
eukaryotes. Monophyletic, unrooted phylogenies based on these sequence data
show that seven of 24 proteins yield a significant
gram-positive-archaebacteria clade/gram-negative- eukaryotic clade. The
phylogenies for these seven proteins cannot be explained by the traditional
three-way split of the eukaryotes, archaebacteria, and eubacteria. Nine of
the 24 proteins yield the traditional gram-positive-gram-negative
clade/archaebacteria-eukaryotic clade. The remaining eight proteins give
phylogenies that cannot be statistically distinguished. These results
support the hypothesis of a chimeric origin for the eukaryotic cell nucleus
formed from the fusion of an archaebacteria and a gram-negative bacteria.
相似文献