首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1168篇
  免费   75篇
  国内免费   69篇
耳鼻咽喉   21篇
儿科学   42篇
基础医学   737篇
口腔科学   1篇
临床医学   24篇
内科学   99篇
皮肤病学   15篇
神经病学   5篇
特种医学   10篇
外科学   6篇
综合类   114篇
预防医学   63篇
眼科学   5篇
药学   65篇
中国医学   102篇
肿瘤学   3篇
  2023年   7篇
  2022年   5篇
  2021年   38篇
  2020年   33篇
  2019年   30篇
  2018年   31篇
  2017年   16篇
  2016年   33篇
  2015年   30篇
  2014年   52篇
  2013年   72篇
  2012年   64篇
  2011年   61篇
  2010年   53篇
  2009年   54篇
  2008年   48篇
  2007年   47篇
  2006年   36篇
  2005年   42篇
  2004年   44篇
  2003年   26篇
  2002年   43篇
  2001年   36篇
  2000年   37篇
  1999年   37篇
  1998年   41篇
  1997年   31篇
  1996年   24篇
  1995年   21篇
  1994年   26篇
  1993年   18篇
  1992年   21篇
  1991年   19篇
  1990年   12篇
  1989年   11篇
  1988年   20篇
  1987年   11篇
  1986年   7篇
  1985年   3篇
  1984年   10篇
  1983年   14篇
  1982年   17篇
  1981年   8篇
  1980年   13篇
  1979年   4篇
  1978年   5篇
  1977年   1篇
排序方式: 共有1312条查询结果,搜索用时 17 毫秒
1.
2.
目的 探索油菜花粉对小鼠雄激素源性脱发的改善作用并研究其作用机制。方法 设立空白组、模型组、阳性药组及给药组,通过脱毛后涂抹0.2%睾酮诱导建立小鼠雄激素源性脱发模型,采用市售5%米诺地尔为阳性药物,0.4 g·mL-1油菜花粉油溶液为给药组,分别观察小鼠毛发生长速度。通过扫描电子显微镜(scanning electron microscope,SEM)、病理组织HE染色观察小鼠毛发质量及毛囊情况。使用免疫荧光染色、免疫印迹试验检测皮肤中VEGF、bFGF水平,ELISA检测血清性激素及活性氧水平。结果 与模型组相比,油菜花粉能显著促进小鼠毛发生长,且能够改善小鼠毛发毛鳞片的状态。机制探究试验表明油菜花粉不能通过调节小鼠激素水平或抗氧化应激起到促进毛发再生作用,但油菜花粉可以提高造模部位皮肤血管生成相关因子bFGF和VEGF的表达。结论 油菜花粉可以促进雄激素源性脱发小鼠毛发再生,其作用机制可能是通过提高bFGF和VEGF水平,促进毛囊周围血管再生从而达到促进毛发再生作用。  相似文献   
3.
The miRNAs are dysregulated in BPH. Rape bee pollen (RBP) is used to improve benign prostatic hyperplasia (BPH). Whether RBP treats BPH by regulating the dysregulated miRNAs remains unclear. Here, we identified miRNAs regulated along with the improvement of BPH by RBP in posterior lobes of prostate in rats. Firstly, to screened miRNAs might relate to improvement of BPH by RBP, we compared differentially expressed miRNAs between BPH model group and RBP group by high-throughput sequencing. As a result, 10 known miRNAs and 17 novel miRNA were up-regulated in RBP group, and 6 known and 13 novel miRNAs were down-regulated. Secondly, among the known miRNAs, we identified those that might relate to BPH by RT-qPCR, while only rno-miR-184 was screened, so we compared it among normal control group, BPH model group and RBP group. The results showed that rno-miR-184 was significantly lower expressed in BPH group, but up-regulated along with the improvement of BPH by RBP. Moreover, expression level of rno-miR-184 was no difference between RBP group and normal control level. Therefore, we considered that RBP might improve BPH through regulating expression of miRNAs like rno-miR-184 in prostate in rats.  相似文献   
4.
5.
6.

Background

A novel subcutaneous allergen immunotherapy formulation (gpASIT+?) containing Lolium perenne peptides (LPP) and having a short up‐dosing phase has been developed to treat grass pollen–induced seasonal allergic rhinoconjunctivitis. We investigated peptide immunotherapy containing the hydrolysate from perennial ryegrass allergens for the optimum dose in terms of clinical efficacy, immunogenicity and safety.

Methods

This prospective, double‐blind, placebo‐controlled, phase IIb, parallel, four‐arm, dose‐finding study randomized 198 grass pollen–allergic adults to receive placebo or cumulative doses of 70, 170 or 370 μg LPP. All patients received weekly subcutaneous injections, with the active treatment groups reaching assigned doses within 2, 3 and 4 weeks, respectively. Efficacy was assessed by comparing conjunctival provocation test (CPT) reactions at baseline, after 4 weeks and after completion. Grass pollen–specific immunoglobulins were analysed before and after treatment.

Results

Conjunctival provocation test (CPT) response thresholds improved from baseline to V7 by at least one concentration step in 51.2% (170 μg; P = .023), 46.3% (370 μg), and 38.6% (70 μg) of patients receiving LPP vs 25.6% of patients receiving placebo (modified per‐protocol set). Also, 39% of patients in the 170‐μg group became nonreactive to CPT vs 18% in the placebo group. Facilitated allergen‐binding assays revealed a highly significant (P < .001) dose‐dependent reduction in IgE allergen binding across all treatment groups (70 μg: 17.1%; 170 μg: 18.8%; 370 μg: 26.4%). Specific IgG4 levels increased to 1.6‐fold (70 μg), 3.1‐fold (170 μg) and 3.9‐fold (370 μg) (mPP).

Conclusion

Three‐week immunotherapy with 170 μg LPP reduced CPT reactivity significantly and increased protective specific antibodies.
  相似文献   
7.
8.
9.

Background

In the context of increased asthma exacerbations associated with climatic changes such as thunderstorm asthma, interest in establishing the link between pollen exposure and asthma hospital admissions has intensified. Here, we systematically reviewed and performed a meta‐analysis of studies on pollen and emergency department (ED) attendance.

Methods

A search for studies with appropriate search strategy in MEDLINE, EMBASE, Web of Science and CINAHL was conducted. Each study was assessed for quality and risk of bias. The available evidence was summarized both qualitatively and meta‐analysed using random‐effects models when moderate heterogeneity was observed.

Results

Fourteen studies were included. The pollen taxa investigated differed between studies, allowing meta‐analysis only of the effect of grass pollen. A statistically significant increase in the percentage change in the mean number of asthma ED presentations (MPC) (pooled results from 3 studies) was observed for an increase in 10 grass pollen grains per cubic metre of exposure 1.88% (95% CI = 0.94%, 2.82%). Time series studies showed positive correlations between pollen concentrations and ED presentations. Age‐stratified studies found strongest associations in children aged 5‐17 years old.

Conclusion

Exposure to ambient grass pollen is an important trigger for childhood asthma exacerbations requiring ED attendance. As pollen exposure is increasingly a problem especially in relation to thunderstorm asthma, studies with uniform measures of pollen and similar analytical methods are necessary to fully understand its impact on human health.  相似文献   
10.

Background

Systemic allergic reactions are a risk for allergen immunotherapy that utilizes intact allergen preparations. We evaluated the safety, efficacy and immune mechanisms of short‐course treatment with adjuvant‐free Lolium perenne peptides (LPP) following a 6‐week dose‐escalation protocol.

Methods

In a prospective, dose‐escalation study, 61 grass pollen–allergic patients received 2 subcutaneous injections of LPP once weekly for 6 weeks. Safety was assessed evaluating local reactions, systemic reactions and adverse events. The clinical effect of LPP was determined by reactivity to the conjunctival provocation test (CPT). Specific IgE, IgG4 and blocking antibodies were measured at baseline (V1), during (V6) and after treatment (V8).

Results

No fatality, serious adverse event or epinephrine use was reported. Mean wheal diameters after injections were <0.6 cm and mean redness diameters <2.5 cm, independent of dose. Transient and mostly mild adverse events were reported in 33 patients. Two patients experienced a grade I and 4 patients a grade II reaction (AWMF classification). At V8, 69.8% of patients became nonreactive to CPT. sIgG4 levels were higher at V6 (8.1‐fold, < .001) and V8 (12.2‐fold, < .001) than at V1. The sIgE:sIgG4 ratio decreased at V6 (?54.6%, < .001) and V8 (?71.6%, < .001) compared to V1. The absolute decrease in IgE‐facilitated allergen binding was 18% (< .001) at V6 and 25% (< .001) at V8.

Conclusion

Increasing doses of subcutaneous LPP appeared safe, substantially diminished reactivity to CPT and induced blocking antibodies as early as 4 weeks after treatment initiation. The benefit/risk balance of LPP immunotherapy remains to be further evaluated in large studies.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号