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71.
Thomas Rodt Christian von Falck Sabine Dettmer Roman Halter Regina Maus Kjetil Ask Martin Kolb Jack Gauldie Florian L?nger Ludwig Hoy Tobias Welte Michael Galanski Ulrich A Maus Jürgen Borlak 《Respiratory research》2010,11(1):181
Background
Micro-computed tomography (micro-CT) is a novel tool for monitoring acute and chronic disease states in small laboratory animals. Its value for assessing progressive lung fibrosis in mice has not been reported so far. Here we examined the importance of in vivo micro-CT as non-invasive tool to assess progression of pulmonary fibrosis in mice over time.Methods
Pulmonary fibrosis was induced in mice by intratracheal delivery of an adenoviral gene vector encoding biologically active TGF-ß1 (AdTGF-ß1). Respiratory gated and ungated micro-CT scans were performed at 1, 2, 3, and 4 weeks post pulmonary adenoviral gene or control vector delivery, and were then correlated with respective histopathology-based Ashcroft scoring of pulmonary fibrosis in mice. Visual assessment of image quality and consolidation was performed by 3 observers and a semi-automated quantification algorithm was applied to quantify aerated pulmonary volume as an inverse surrogate marker for pulmonary fibrosis.Results
We found a significant correlation between classical Ashcroft scoring and micro-CT assessment using both visual assessment and the semi-automated quantification algorithm. Pulmonary fibrosis could be clearly detected in micro-CT, image quality values were higher for respiratory gated exams, although differences were not significant. For assessment of fibrosis no significant difference between respiratory gated and ungated exams was observed.Conclusions
Together, we show that micro-CT is a powerful tool to assess pulmonary fibrosis in mice, using both visual assessment and semi-automated quantification algorithms. These data may be important in view of pre-clinical pharmacologic interventions for the treatment of lung fibrosis in small laboratory animals. 相似文献72.
Aims were to estimate the extent of genetic heterogeneity in environmental variance. Data comprised 99 535 records of 35-day body weights from broiler chickens reared in a controlled environment. Residual variance within dam families was estimated using ASREML, after fitting fixed effects such as genetic groups and hatches, for each of 377 genetically contemporary sires with a large number of progeny (> 100 males or females each). Residual variance was computed separately for male and female offspring, and after correction for sampling, strong evidence for heterogeneity was found, the standard deviation between sires in within variance amounting to 15–18% of its mean. Reanalysis using log-transformed data gave similar results, and elimination of 2–3% of outlier data reduced the heterogeneity but it was still over 10%. The correlation between estimates for males and females was low, however. The correlation between sire effects on progeny mean and residual variance for body weight was small and negative (-0.1). Using a data set bigger than any yet presented and on a trait measurable in both sexes, this study has shown evidence for heterogeneity in the residual variance, which could not be explained by segregation of major genes unless very few determined the trait. 相似文献
73.
74.
Brandon AE Hoy AJ Wright LE Turner N Hegarty BD Iseli TJ Julia Xu X Cooney GJ Saha AK Ruderman NB Kraegen EW 《Archives of biochemistry and biophysics》2011,(2):3447-141
Glucose infusion into rats causes skeletal muscle insulin resistance that initially occurs without changes in insulin signaling. The aim of the current study was to prolong glucose infusion and evaluate other events associated with the transition to muscle insulin resistance. Hyperglycemia was produced in rats by glucose infusion for 3, 5 and 8 h. The rate of infusion required to maintain hyperglycemia was reduced at 5 and 8 h. Glucose uptake into red quadriceps (RQ) and its incorporation into glycogen decreased between 3 and 5 h, further decreasing at 8 h. The earliest observed change in RQ was decreased AMPKα2 activity associated with large increases in muscle glycogen content at 3 h. Activation of the mTOR pathway occurred at 5 h. Akt phosphorylation (Ser473) was decreased at 8 h compared to 3 and 5, although no decrease in phosphorylation of downstream GSK-3β (Ser9) and AS160 (Thr642) was observed. White quadriceps showed a similar but delayed pattern, with insulin resistance developing by 8 h and decreased AMPKα2 activity at 5 h. These results indicate that, in the presence of a nutrient overload, alterations in muscle insulin signaling occur, but after insulin resistance develops and appropriate changes in energy/nutrient sensing pathways occur. 相似文献
75.
Microbial communities in sugarcane field soils with and without a sugarcane cropping history 总被引:1,自引:0,他引:1
Microbial communities in rhizosphere soil from sugarcane (Saccharum inter-specific hybrids) and bulk soil were compared at paired field sites with and without a sugarcane cropping history to determine whether monoculture affects soil microbial community composition. Differences were evaluated for culturable microorganisms and functional diversity indicated by community level physiological profiles (CLPP). Qualitative differences in rhizosphere bacterial communities were detected between sites with no sugarcane cropping history (Nsite) and sites with a long-term sugarcane cropping history (Lsite). More fluorescent pseudomonads were detected in Nsite than Lsite rhizosphere soil at two of three sites, and Actinobacteria were more numerous in Nsite than Lsite rhizosphere soil at one site. Fusarial fungi were more numerous in Nsite than Lsite rhizosphere soils. Bacteria were more numerous in rhizosphere soil compared to bulk soil. Total bacterial, pseudomonad, and Actinobacteria population densities were greater in bulk soil from an Nsite compared to an Lsite. CLPP distinguished bulk from rhizosphere soil at one of two sites and Nsite and Lsite rhizosphere soils at two of four sites. Site affected CLPP similarity more than cropping history. The results demonstrated that sugarcane monoculture can affect the composition of the microbial community in field soil. The findings have possible implications for reduced yields associated with sugarcane monoculture. 相似文献
76.
Thirty five females and 15 males of New Zealand White mature rabbits about 6 months of age, were assigned to 1–5 dietary treatments (7 does+3 bucks for each): uncontaminated control diet, naturally aflatoxin contaminated diet without or with 1,2 and 3% bentonite. Rabbit fed with the aflatoxin-diet had a decreased (P<0.01 or 0.05) physical semen characteristics of bucks and a reproductive performance traits of does. The values of conception rate (%), gestation length (days), litter size (n) and litter weights (g) at birth and viability (%) of litters of doe rabbits, fed with the aflatoxin-diet, recorded, respectively: 64.5; 31.0; 4.4; 275.0 and 57.1 versus 85.6; 30.3; 7.9; 508.0; and 100 for those fed with the uncontaminated diet. Addition of bentonite to the aflatoxin contaminated diet improved in general the physical semen characteristics of buck and reproductive performance traits of doe rabbits. The results of the study demonstrate that adding 1% of Egyptian raw bentonite to the naturally aflatoxin contaminated rabbit diets can provide an effective, cheap and safe practical technique for preventing the aflatoxicosis in mature rabbits. 相似文献
77.
A. C. Mason G. K. Morris R. R. Hoy 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1999,184(5):543-551
Peripheral auditory frequency tuning in the ensiferan insect Cyphoderris monstrosa (Orthoptera: Haglidae) was examined by comparing tympanal vibrations and primary auditory receptor responses. In this species
there is a mis-match between the frequency of maximal auditory sensitivity and the frequency content of the species' acoustic
signals. The mis-match is not a function of the mechanical properties of the tympanum, but is evident at the level of primary
receptors. There are two classes of primary receptors: low-tuned and broadly tuned. Differences in the absolute sensitivity
of the two receptor types at the male song frequency would allow the auditory system to discriminate intraspecific signals
from sounds containing lower frequencies. Comparisons of tympanal and receptor tuning indicated that the sensitivity of the
broadly tuned receptors did not differ from that of the tympanum, while low-tuned receptors had significantly narrower frequency
tuning. The results suggest that the limited specialization for the encoding of intraspecific signals in the auditory system
of C. monstrosa is a primitive rather than a degenerate condition. The limited specialization of C. monstrosa may reflect the evolutionary origin of communication-related hearing from a generalized precursor through the addition of
peripheral adaptations (tympana, additional receptors) to enhance frequency sensitivity and discrimination.
Accepted: 13 March 1999 相似文献
78.
79.
Structural alterations in the Bacillus subtilis Spo0A regulatory protein which suppress mutations at several spo0 loci 总被引:16,自引:11,他引:5 下载免费PDF全文
G Spiegelman B Van Hoy M Perego J Day K Trach J A Hoch 《Journal of bacteriology》1990,172(9):5011-5019
Secondary site mutations that restore sporulation to sporulation-defective spo0F or spo0B deletion mutants were found to reside in the spo0A gene. Sequence analysis of 23 such sof mutants showed that the sof mutations fell into six classes of missense codon changes, primarily in the conserved amino-terminal domain of the response regulator Spo0A protein. Changes were observed in codons 12, 14, 60, 92, and 121. The residues affected were predominantly located in the potential turn regions at one end of the amino-terminal conserved domain on the same topological face as the active site aspartate residues. The ability of sof mutations to suppress deficiencies in the transmitter kinases, KinA and KinB, of two-component regulatory systems was tested. All of the sof mutations suppressed the sporulation deficiency of kinA mutants but only two classes among five tested suppressed kinB mutations. sof mutants segregated Spo- colonies at high frequency. Five of these Spo- mutants were found to result from mutations in the spo0A locus that reversed the effect of the sof mutatation. One of these was sequenced and found to have the original sof mutation and a new mutation, sos, at codon 105. The accumulation of sos mutations in sof strains suggested that the sof mutations have a subtle, yet deleterious, effect on the growth of the cell. The results suggested that the sof mutations increase the avidity for or reactivity with transmitter kinases in an allele-specific manner, although in some cases it is possible that the sof mutations obviate the need for phosphorylation to activate the Spo0A protein. An alternative hypothesis is presented in which the sof mutations play the role of bypass mutations for kinases. 相似文献
80.