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121.
在实验室条件下研究了极端温度对海刺猬的存活率、摄食率、生长以及组织器官等方面的影响。实验设置两个处理组温度为30°C和-2℃,对照组为自然水温(19~23℃),每组设置3个重复,每个重复60枚海刺猬,实验周期为56 d。结果表明:高温组海刺猬实验温度升到30℃后2 d内全部死亡,其平均摄食量(5.19±1.31 g·ind-1)极显著小于对照组(15.15±1.58 g·ind-1)(P0.01);低温组和对照组之间海刺猬存活率差异不显著(P0.05);但低温组海刺猬平均摄食量(0.18±0.04 g·ind-1)极显著小于对照组(10.90±0.33 g·ind-1)(P0.01);56 d内低温组海刺猬个体湿重极显著小于对照组(P0.01);低温组海刺猬口器湿重、壳湿重、性腺湿重、壳干重、口器指数、壳指数极显著小于对照组(P0.01),性腺干重、口器干重显著小于对照组(P0.05);但性腺指数与对照组无显著差别(P0.05);低温组海刺猬最大承受压力极显著小于对照组(P0.01);在实验室条件下,海刺猬(2~3 g·ind-1)无法长时间在高温环境(30℃)下存活,而能在低温环境(-2℃)下存活但其摄食、生长和性腺性状影响极显著。 相似文献
122.
Kavita Venkataraman ChinMeng Khoo Hwee Lin Wee Chuen Seng Tan Stefan Ma Derrick Heng Jeannette Lee E. Shyong Tai Julian Thumboo 《PloS one》2014,9(11)
Background
Health related quality of life (HRQoL) is an important dimension of individuals'' well-being, and especially in chronic diseases like diabetes and hypertension. The objective of this study was to evaluate the contributions of disease process, comorbidities, medication or awareness of the disease to HRQoL in diabetes mellitus, hypertension and dyslipidemia.Methods
This was a cross-sectional study of 3514 respondents from the general community in Singapore, assessed for HRQoL, disease and comorbid conditions through self-report, clinical and laboratory investigations. HRQoL was assessed using SF-36 health survey version 2. For each condition, participants were categorized as having 1) no disease, 2) undiagnosed, 3) diagnosed, not taking medication, and 4) diagnosed, taking medication. Analysis used one-way ANOVA and multiple linear regression.Results
Diagnosed disease was associated with lower physical health component summary (PCS) scores across all three conditions. After adjustment for comorbidities, this association remained significant only for those not on medication in diabetes (−2.7±1.2 points, p = 0.03) and dyslipidemia (−1.3±0.4 points, p = 0.003). Diagnosed hypertension (no medication −2.6±0.9 points, p = 0.002; medication −1.4±0.5 points, p = 0.004) and dyslipidemia (no medication −0.9±0.4 points, p = 0.03; medication −1.9±0.5 points, p<0.001) were associated with lower mental health component summary (MCS) scores. Undiagnosed disease was associated with higher MCS in diabetes (2.4±1.0 points, p = 0.01) and dyslipidemia (0.8±0.4 points, p = 0.045), and PCS in hypertension (1.2±0.4 points, p = 0.004).Conclusions
Disease awareness was associated with lower HRQoL across the diseases studied, with PCS associations partially mediated by comorbidities. Equally importantly, undiagnosed disease was not associated with HRQoL deficits, which may partly explain why these individuals do not seek medical care. 相似文献123.
Zhuang X Jiang J Li J Ma Q Xu Y Xue Y Xu Z Chong K 《The Plant journal : for cell and molecular biology》2006,48(4):581-591
Development and organogenesis in both dicot and monocot plants are highly dependent on polar auxin transport (PAT), which requires the proper asymmetric localization of both auxin influx and efflux carriers. In the model dicot plant Arabidopsis thaliana, the trafficking and localization of auxin efflux facilitators such as PIN-FORMED1 (PIN1) are mediated by GNOM, a guanine-nucleotide exchange factor (GEF) for the ADP-ribosylation factor (ARF) family of small GTPases, but molecular regulators of the auxin influx facilitators remain unknown. Here, we show that over-expression of OsAGAP, an ARF-GTPase-activating protein (ARF-GAP) in rice, impaired PAT and interfered with both primary and lateral root development. The lateral root phenotype could be rescued by the membrane-permeable auxin 1-naphthyl acetic acid, but not by indole 3-acetic acid (IAA) or by 2,4-dichloro-phenoxyacetic acid, which require influx facilitators to enter the cells. OsAGAP-over-expressing plants had alterations in vesicle trafficking and localization of the presumptive A. thaliana auxin-influx carrier AUX1, but not in the localization of the auxin efflux facilitators. Together, our data suggest that OsAGAP has a specific role in regulating vesicle trafficking pathways such as the auxin influx pathway, which in turn controls auxin-dependent root growth in plants. 相似文献
124.
Kevin Kit Siong Ng Soon Leong Lee Leng Guan Saw Joshua B. Plotkin Chong Lek Koh 《Tree Genetics & Genomes》2006,2(3):121-131
Analyses of the spatial distribution pattern, spatial genetic structure and genetic diversity were carried out using a 33-ha plot in a hill dipterocarp forest for three dipterocarps with different habitat preferences, i.e. Shorea curtisii on the ridges, Shorea leprosula in the valleys and Shorea macroptera both on the ridges and in the valleys. The significant spatial aggregation in small-diameter trees of all the three species was explained by limited seed dispersal. At the large-diameter trees, only S. macroptera showed random distribution and this might further prove that S. macroptera is habitat generalist, whilst S. curtisii and S. leprosula are habitat specific. The levels of genetic diversity estimated based on five microsatellite loci were high and comparable in all the three studied species. As the three studied species reproduced mainly through outcrossing, the observed high levels of genetic diversity might support the fact that the plant mating system can be used as guideline to infer the levels of genetic diversity, regardless of whether the species is habitat specific or habitat generalist. The lack of spatial genetic structure but significant aggregation in the small-diameter trees of all the three species might indicate limited seed dispersal but extensive pollen flow. Hence, if seed dispersal is restricted but pollen flow is extensive, significant spatial aggregation but no spatial genetic structure will be observed at the small-diameter trees, regardless of whether the species is habitat specific or habitat generalist. The inferred extensive pollen flow might indicate that energetic pollinators are involved in the pollination of Shorea species in the hill dipterocarp forests. 相似文献
125.
Yong WD Xu YY Xu WZ Wang X Li N Wu JS Liang TB Chong K Xu ZH Tan KH Zhu ZQ 《Planta》2003,217(2):261-270
A vernalization-related gene VER2 was isolated from winter wheat ( Triticum aestivum L.) using a differential screening approach. The deduced VER2 is a lectin-like protein of 300 amino acids, which contains the presence of a jacalin-like GWG domain. RNA in situ hybridization results demonstrated that VER2 gene expression is restricted to the marginal meristems of immature leaves in vernalized wheat seedlings. No hybridization signal was detected in the epidermal tissue and vascular bundles. However, "devernalization" resulted in the silencing of VER2 gene activity. The gene expression pattern of VER2 induced by jasmonate was similar to that induced by vernalization. Antisense inhibition of VER2 in transgenic wheat showed that heading and maturation time were delayed up to 6 weeks compared with non-transformed wheat and the pBI121empty-vector-transformed wheat. Tissue degeneration at the top of the spike was also noticed in the antisense inhibited transgenic wheat. These results suggest that VER2 plays an important role in vernalization signaling and spike development in winter wheat. 相似文献
126.
Background
Mapping the expression changes during breast cancer development should facilitate basic and translational research that will eventually improve our understanding and clinical management of cancer. However, most studies in this area are challenged by genetic and environmental heterogeneities associated with cancer.Methodology/Principal Findings
We conducted proteomics of the MCF10AT breast cancer model, which comprises of 4 isogenic xenograft-derived human cell lines that mimic different stages of breast cancer progression, using iTRAQ-based tandem mass spectrometry. Of more than 1200 proteins detected, 98 proteins representing at least 20 molecular function groups including kinases, proteases, adhesion, calcium binding and cytoskeletal proteins were found to display significant expression changes across the MCF10AT model. The number of proteins that showed different expression levels increased as disease progressed from AT1k pre-neoplastic cells to low grade CA1h cancer cells and high grade cancer cells. Bioinformatics revealed that MCF10AT model of breast cancer progression is associated with a major re-programming in metabolism, one of the first identified biochemical hallmarks of tumor cells (the “Warburg effect”). Aberrant expression of 3 novel breast cancer-associated proteins namely AK1, ATOX1 and HIST1H2BM were subsequently validated via immunoblotting of the MCF10AT model and immunohistochemistry of progressive clinical breast cancer lesions.Conclusion/Significance
The information generated by this study should serve as a useful reference for future basic and translational cancer research. Dysregulation of ATOX1, AK1 and HIST1HB2M could be detected as early as the pre-neoplastic stage. The findings have implications on early detection and stratification of patients for adjuvant therapy. 相似文献127.
Jessica K. Bartfield Norma Ojehomon Karen W. Huskey Roger B. Davis Christina C. Wee 《Obesity (Silver Spring, Md.)》2010,18(2):430-432
Limited data exist about patient preferences and self‐efficacy for different diets. We explored the preferences and self‐efficacy of primary care patients for reducing fat, reducing carbohydrates, or reducing calories. We conducted a self‐administered survey study of 71 primary care patients (response rate of 52%). Of patients, 59%, 53%, and 60% had high self‐efficacy for reducing fat, reducing carbohydrates, and reducing calories from their diet, respectively. Preferences were comparable, with 76% highly willing to reduce fat, 76% highly willing to reduce carbohydrates, and 72% of patients highly willing to reduce calories/portions. Female sex and higher BMI were associated with high self‐efficacy for all three dietary changes. A significantly higher proportion of nonwhites than whites had high self‐efficacy for reducing fat and reducing carbohydrates (P < 0.05). Obese patients in our study have similarly high willingness and self‐efficacy and comparable preferences for adopting changes consistent with three popular diets. 相似文献
128.
129.
Thibaud P. Coroller Raymond H. Mak John H. Lewis Elizabeth H. Baldini Aileen B. Chen Yolonda L. Colson Fred L. Hacker Gretchen Hermann David Kozono Edward Mannarino Christina Molodowitch Jon O. Wee David J. Sher Joseph H. Killoran 《PloS one》2014,9(4)
Purpose
To examine the frequency and potential of dose-volume predictors for chest wall (CW) toxicity (pain and/or rib fracture) for patients receiving lung stereotactic body radiotherapy (SBRT) using treatment planning methods to minimize CW dose and a risk-adapted fractionation scheme.Methods
We reviewed data from 72 treatment plans, from 69 lung SBRT patients with at least one year of follow-up or CW toxicity, who were treated at our center between 2010 and 2013. Treatment plans were optimized to reduce CW dose and patients received a risk-adapted fractionation of 18 Gy×3 fractions (54 Gy total) if the CW V30 was less than 30 mL or 10–12 Gy×5 fractions (50–60 Gy total) otherwise. The association between CW toxicity and patient characteristics, treatment parameters and dose metrics, including biologically equivalent dose, were analyzed using logistic regression.Results
With a median follow-up of 20 months, 6 (8.3%) patients developed CW pain including three (4.2%) grade 1, two (2.8%) grade 2 and one (1.4%) grade 3. Five (6.9%) patients developed rib fractures, one of which was symptomatic. No significant associations between CW toxicity and patient and dosimetric variables were identified on univariate nor multivariate analysis.Conclusions
Optimization of treatment plans to reduce CW dose and a risk-adapted fractionation strategy of three or five fractions based on the CW V30 resulted in a low incidence of CW toxicity. Under these conditions, none of the patient characteristics or dose metrics we examined appeared to be predictive of CW pain. 相似文献130.