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   2569篇
  免费   157篇
  国内免费   20篇
耳鼻咽喉   28篇
儿科学   90篇
妇产科学   64篇
基础医学   239篇
口腔科学   77篇
临床医学   247篇
内科学   547篇
皮肤病学   67篇
神经病学   104篇
特种医学   189篇
外国民族医学   1篇
外科学   360篇
综合类   59篇
一般理论   3篇
预防医学   300篇
眼科学   48篇
药学   137篇
中国医学   8篇
肿瘤学   178篇
  2023年   32篇
  2022年   71篇
  2021年   113篇
  2020年   75篇
  2019年   63篇
  2018年   101篇
  2017年   80篇
  2016年   57篇
  2015年   73篇
  2014年   108篇
  2013年   181篇
  2012年   162篇
  2011年   168篇
  2010年   114篇
  2009年   98篇
  2008年   120篇
  2007年   110篇
  2006年   109篇
  2005年   94篇
  2004年   92篇
  2003年   73篇
  2002年   62篇
  2001年   34篇
  2000年   24篇
  1999年   33篇
  1998年   35篇
  1997年   40篇
  1996年   40篇
  1995年   25篇
  1994年   23篇
  1993年   16篇
  1992年   16篇
  1991年   12篇
  1990年   21篇
  1989年   26篇
  1988年   24篇
  1987年   23篇
  1986年   21篇
  1985年   16篇
  1984年   16篇
  1983年   8篇
  1982年   19篇
  1981年   10篇
  1980年   13篇
  1979年   10篇
  1978年   10篇
  1977年   11篇
  1976年   8篇
  1975年   9篇
  1973年   9篇
排序方式: 共有2746条查询结果,搜索用时 15 毫秒
81.
Despite operator experience and improved catheter technology, acute vessel closure is inherently associated with percutaneous transluminal coronary angioplasty (PTCA) of complex lesions. This case study describes a patient who developed an occlusive dissection post PTCA at the bifurcation of the left anterior descending artery (LAD) and its diagonal branch. The “T”-shaped wiktor stent placement immediately re-establishes full flow, obviating the necessity for emergent surgery. © 1996 Wiley-Liss, Inc.  相似文献   
82.
To better characterize the role of the lipoprotein lipase (LPL) gene in the determination of triglyceride levels in healthy subjects, a study was performed in 193 nuclear families (384 parents, means age = 42.0 ± 5.2 years; 399 offspring, mean age = 14.6 ± 4.3 years) volunteering to have a free health checkup examination. The pattern of familial resemblance was compatible with a zero correlation between spouses, a weak father-offspring correlation (0.099 ± 0.054; P < 0.07), and significant mother-offspring (0.235 ± 0.053; P < 10−4) and sib-sib (0.294 ± 0.064; P < 10−4) correlations. Associations of triglyceride levels with the LPL HindIII and PvuII polymorphisms were investigated by a familial measured genotype analysis, specifying sex- and age-dependent polymorphism effects. The effects associated with both polymorphisms were significant only in fathers, the H+ and P+ alleles being associated with raised triglyceride levels. The HindIII and PvuII polymorphisms explained 3.5% and 3%, respectively, of the variability of triglycerides in fathers. The relationship was weakened after prior adjustment on body mass index, but remained significant for PvuII. Because of the lack of effect in mothers and offspring, the polymorphisms did not contribute to the covariance of triglyceride levels in relatives. In conclusion, this family study showed a weak relationship of the HindIII and PvuII polymorphisms to plasma triglyceride levels in young healthy male subjects. The effects detectable only in fathers suggest a possible modulation of the LPL expression by hormonal or lifestyle factors. © 1996 Wiley-Liss, Inc.  相似文献   
83.
There has been an increasing number of reported cases of acute hepatitis of unknown origin in previously healthy children since first reported on March 31,2022.This clinical syndrome is identified by jaundice and markedly elevated liver enzymes with increased aspartate transaminase and/or alanine amino transaminase(greater than 500 IU/L).We conducted an inclusive literature review with respect to acute hepatitis outbreaks in children using the search terms acute hepatitis,outbreak,children,sever...  相似文献   
84.
A 3‐year‐old child presented with recurrent chest pain for 3 months, echocardiography showed a thorn inside the left ventricle, the patient was diagnosed with foreign body complicated with infective endocarditis and received proper treatment, and operation was performed after inflammatory reaction subsided.  相似文献   
85.
Soft corals belonging to the family Nephtheidae have been appreciated as marine sources of diverse metabolites with promising anticancer potential. In view of that, the current work investigates the anti-proliferative potential of the crude extract, different fractions, and green synthesized silver nanoparticles (AgNPs) of the Red Sea soft coral, Nephthea sp. against a panel of tumor cell lines. The metabolic pool of the soft coral under study was also explored via an LC-HR-ESI-MS metabolomics approach, followed by molecular docking analysis of the characterized metabolites against the target proteins, EGFR, VEGFR, and HER2 (erbB2) that are known to be involved in cancer cell proliferation, growth, and survival. Overall, the n-butanol fraction of Nephthea sp. exhibited the highest inhibitory activities against MCF7 (breast cancer) and A549 (lung cancer) cell lines, with interesting IC50 values of 2.30 ± 0.07 and 3.12 ± 0.10 μg ml−1, respectively, whereas the maximum growth inhibition of HL60 (leukemia) cells was recorded by the total extract (IC50 = 2.78 ± 0.09 μg ml−1). More interestingly, the anti-proliferative potential of the total soft coral extract was evidently improved when packaged in the form of biogenic AgNPs, particularly against A549 and MCF7 tumor cells, showing IC50 values of 0.72 ± 0.06 and 9.32 ± 0.57 μg ml−1, respectively. On the other hand, metabolic profiling of Nephthea sp. resulted in the annotation of structurally diverse terpenoids, some of which displayed considerable binding affinities and molecular interactions with the studied target proteins, suggesting their possible contribution to the anti-proliferative properties of Nephthea sp. via inhibition of tyrosine kinases, especially the EGFR type. Taken together, the present findings highlighted the relevance of Nephthea sp. to future anticancer drug discovery and provided a base for further work on the green synthesis of a range of bioactive NPs from marine soft corals.

The cytotoxic potential of the crude extract, different fractions, and green synthesized nanoparticles of the soft coral Nephthea sp. was studied, supported by LC-HR-ESI-MS metabolomics analysis and molecular docking of the dereplicated compounds.  相似文献   
86.
From its uses in ancient civilisations, copper has an established history as an antimicrobial agent. Extensive research has determined the efficacy and mechanism of copper''s antimicrobial activity against microorganisms. The process is multifaceted with the main mechanism of bactericidal activity being the generation of reactive oxygen species (ROS), which irreversibly damages membranes. Copper ions released from surfaces lead to RNA degradation and membrane disruption of enveloped viruses. For fungi, the mechanism involves the physical deterioration of the membrane and copper ion influx. Due to variations in the experimental parameters, it is difficult to compare studies directly. In this review article, we outline the importance of the experimental conditions currently employed and how they bear little resemblance to real-world conditions. We endorse previous recommendations calling for an update to industrial standard tests.

The causes of death for each microorganism by CuNPs and metallic copper is summarised.  相似文献   
87.
88.
89.
neurogenetics - Evidence about the link between glucocerebrosidase (GCase) and parkinsonism is growing. Parkinsonism was described in adult type 1 Gaucher disease (GD); few case reports described...  相似文献   
90.
Backgrounds: Toll-like receptors 2; 4 (TLR2;4) are an essential component of the innate immunity and play an important role in immune-surveillance and immune response to various microorganisms. This study aimed to investigate the association between TLR2 and TLR4 polymorphism and the risk of acquiring severe infections, and impact on AML patient’s outcome. Subjects and methods: Using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP); we analyzed three SNPs in the TLR2 (Arg753Gln) and TLR4 (Asp299Gly and Thr399Ile) in 120 AML patients and 100 healthy control subjects. Results: No significant differences in genotype or alleles frequency between healthy controls and AML patients regarding TLR2 Arg753Gln, TLR4 Asp299Gly and TLR4 Thr399Ile polymorphisms (P>0.05 for all). Neutropenic fever was detected in 110 out of 120 (91.7%) of the studied AML patients. The sepsis and pneumonia were identified in 20 out of 120 patients (16.7%). The incidence of sepsis was associated with TLR2 Arg753Gln: AG genotypes, A allele and TLR4 Asp299Gly: CT genotype and C allele as compared to other genotypes and alleles. Moreover; TLR2 (Arg753Gln) GG polymorphisms significantly associated with shortest overall survival (OS) and shortest disease-free survival (DFS); while TLR4 polymorphisms affect the DSF only but not OS. In AML patients TLR2 Arg753Gln gene polymorphism is associated with high susceptibility to sepsis and TLR4 (Asp299Gly and Thr399Ile) gene polymorphism is associated with high susceptibility for both pneumonia; and sepsis. Conclusion: TLR2 Arg753Gln (AG; GG genotype) polymorphisms are associated with shortest OS and DFS. Moreover; significant association between TLR2 polymorphisms, TLR4 Arg753Gln polymorphisms and risk of severe infections in AML patients was documented.  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