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191.
Relatedness between single nucleotide polymorphisms in IL8 and TLR4 genes and digital dermatitis resistance/susceptibility was investigated in seventy Holstein dairy cows. Animals were assigned into two groups, affected group (n?=?35) and resistant group (n?=?35) based on clinical signs and previous history of farm clinical records. Blood samples were collected for DNA extraction to ampliy fragments of 267-bp and 382-bp for IL8 and TLR4 genes, respectively. PCR-DNA sequencing revealed three SNPs in each of IL8 and TLR4 genes. The identified SNPs associated with digital dermatitis resistance were C94T, A220G, and T262A for IL8 and C118T for TLR4. However, the G349C and C355A SNPs in TLR4 gene were associated with digital dermatitis susceptibility. Chi-square analysis for comparison the distribution of all identified SNPs in both IL8 and TLR4 genes between resistant and affected animals showed no significant variation among the identified SNPs in IL8 gene. Meanwhile, there was a significant variation in case of TLR4 gene. As a pilot study, the present results revealed that identified SNPs in IL8 and TLR4 genes can be used as a genetic marker and predisposing factor for resistance/susceptibility to digital dermatitis in dairy cows. However, TLR4 gene may be a potential candidate for such disease.  相似文献   
192.
The ability to carry out systematic, accurate and repeatable vegetation surveys is an essential part of long-term scientific studies into ecosystem biodiversity and functioning. However, current widely used traditional survey techniques such as destructive harvests, pin frame quadrats and visual cover estimates can be very time consuming and are prone to subjective variations. We investigated the use of digital image techniques as an alternative way of recording vegetation cover to plant functional type level on a peatland ecosystem. Using an established plant manipulation experimental site at Moor House NNR (an Environmental Change Network site), we compared visual cover estimates of peatland vegetation with cover estimates using digital image classification methods, from 0.5 m × 0.5 m field plots. Our results show that digital image classification of photographs taken with a standard digital camera can be used successfully to estimate dwarf-shrub and graminoid vegetation cover at a comparable level to field visual cover estimates, although the methods were less effective for lower plants such as mosses and lichens. Our study illustrates the novel application of digital image techniques to provide a new way of measuring and monitoring peatland vegetation to the plant functional group level, which is less vulnerable to surveyor bias than are visual field surveys. Furthermore, as such digital techniques are highly repeatable, we suggest that they have potential for use in long-term monitoring studies, at both plot and landscape scales.  相似文献   
193.
Data from 142 male and 43 female samples of African populations have been used to analyze the geographical variation of digital dermatoglyphics (arches, loops, whorls, and pattern intensity index) in Africa. The patterns of geographical variation have been summarized as contours of sixth-degree polynomial surfaces by means of trend-surface analysis. As pointed out by early studies, Africa exhibits geographical clines of digital dermatoglyphic patterns. However, only some of the frequency gradients previously described for the region find confirmation in the present study.  相似文献   
194.
We report that α-tocotrienol quinone (ATQ3) is a metabolite of α-tocotrienol, and that ATQ3 is a potent cellular protectant against oxidative stress and aging. ATQ3 is orally bioavailable, crosses the blood-brain barrier, and has demonstrated clinical response in inherited mitochondrial disease in open label studies. ATQ3 activity is dependent upon reversible 2e-redox-cycling. ATQ3 may represent a broader class of unappreciated dietary-derived phytomolecular redox motifs that digitally encode biochemical data using redox state as a means to sense and transfer information essential for cellular function.  相似文献   
195.
随着现代技术和信息技术的发展及其在高等学校教学领域中的广泛应用,利用现代网络技术,构建数字化网络多媒体教学平台已经成为新的教学理念。本文对建设适用于以学生自主学习为主导的数字化教学及考评模式进行了初步探讨。  相似文献   
196.
This paper studies employee health in the context of digital transformation in Germany. While most studies have focused on mental health, we focus on physical health. Using pooled survey data, we estimate how an increased use of computers in the workplace relates to subjective health and work-related health complaints. We find that employees using the computer frequently report better subjective health and a significantly lower prevalence of back pain and physical exhaustion. After controlling for physical work exposures, the health-promoting effect of computer use is much smaller, suggesting that high computer use is associated with a less physically demanding work environment, which in turn relates to better (physical) health outcomes. While digital transformation seems to foster physical health, there are hints that mental health could deteriorate. Thus, the focus of occupational health is shifting towards the prevention of mental stress.  相似文献   
197.
目的:比较冠状动脉CT血管成像(CT angiography,CTA)以及数字减影血管造影(digital subtraction angiography,DSA)诊断冠心病的临床价值差异。方法:选择2013年12月至2020年3月安徽医科大学第三附属医院、安徽医科大学第四附属医院收治的60例冠心病患者为研究对象,首先对其实施多排螺旋CT冠状动脉血管造影检测(CTA),而后2 w内再对其实施DSA检测,比较两种检测方式对不同血管狭窄程度、不同性质斑块检出率的差异,最后以DSA检测结果为金标准,评估CTA对冠状动脉狭窄诊断的一致性、灵敏度、特异度、阳性预测值和阴性预测值。结果:(1)CTA检测狭窄血管共计387支,轻度狭窄152支(39.28%),中度狭窄118支(30.49%),重度狭窄105支(27.13%),闭塞12支(3.10%);DSA检测狭窄血管392支,轻度狭窄150支(38.27%),中度狭窄124支(31.63%),重度狭窄112支(28.57%),闭塞6支(1.53%),两组各血管狭窄类型比较差异无统计学意义(P0.05);(2)CTA检测斑块69个,其中钙化斑43个(62.32%),非钙化斑26个(37.68%),DSA检测斑块61个,其中钙化斑33个(54.10%),非钙化斑28个(45.50%),两种检测方式差异无统计学意义(P0.05);(3)以DSA检测为金标准,CTA对重度及以上血管狭窄诊断一致性为99.23%,特异度为98.31%,灵敏度为99.64%,阳性预测值为99.15%,阴性预测值为99.27%。结论:与DSA相比,CTA对冠心病患者血管狭窄的诊断价值相当,且属于无创检测,在冠心病早期筛查中临床应用价值更高。  相似文献   
198.
A tracking and reporting system was developed to monitor radiation dose in X-ray breast imaging. We used our tracking system to characterize and compare the mammographic practices of five breast imaging centers located in the United States and Brazil. Clinical data were acquired using eight mammography systems comprising three modalities: computed radiography (CR), full-field digital mammography (FFDM), and digital breast tomosynthesis (DBT). Our database consists of metadata extracted from 334,234 images. We analyzed distributions and correlations of compressed breast thickness (CBT), compression force, target-filter combinations, X-ray tube voltage, and average glandular dose (AGD). AGD reference curves were calculated based on AGD distributions as a function of CBT. These curves represent an AGD reference for a particular population and system. Differences in AGD and imaging settings were attributed to a combination of factors, such as improvements in technology, imaging protocol, and patient demographics. The tracking system allows the comparison of various imaging settings used in screening mammography, as well as the tracking of patient- and population-specific breast data collected from different populations.  相似文献   
199.
PurposeTo assess if single shot acquisitions with solid-state dosimeters as well as Robson’s method could replace ionization chambers for tube output and HVL measurements, saving medical physicists time.Material and methodsThe energy responses of 4 solid-state dosimeters with automatic calculation of HVL were compared to ionization chamber measurements. Five anode/filter combinations were tested: Mo/Mo, Mo/Rh, Rh/Rh, W/Rh and W/Ag, from 24kVp to 35kVp. Tube output was measured free in air. HVL was measured using the solid-state dosimeters (single-shot acquisition), then manually with aluminum sheets and finally using the parametrization method of Robson.ResultsDeviations in tube output and HVL related to energy response in SSD were small in the 25–32 kVp range, and for tube output typically within 3%. Extrapolation using the Robson parametrization was within 5%, except for one device and for all W/Rh. Deviations of the HVL using the single shot approach were within 10% of the gold standard data. Larger deviations were found at the extreme tube voltages of 24kVp and 35kVp (maximum of 24%).ConclusionWith the assumption that deviations in tube output of 5% and for HVL of 10% are acceptable, all tested solid state dosimeters met this criterion in the tube voltage range of 26kVp to 32kVp. Robson’s method worked well for the spectra for which the method was developed, making both alternative approaches trustworthy for routine quality assurance purposes.  相似文献   
200.
Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylo-genetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa), average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ?81 aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ?10 exons of small size [?176 nucleotides (nt)]. Streptophyta have on average only ?5.7 exons of medium size (?230 nt). Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400 nt). Among sub-cellular compartments, membrane proteins are the largest (?520 aa), whereas the smallest proteins correspond to the gene ontology group of ribosome (?240 aa). Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ?34%more but ?20%smal-ler proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes.  相似文献   
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