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   557篇
  免费   33篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   33篇
妇产科学   15篇
基础医学   60篇
口腔科学   10篇
临床医学   43篇
内科学   131篇
皮肤病学   8篇
神经病学   50篇
特种医学   17篇
外科学   70篇
综合类   11篇
预防医学   27篇
眼科学   19篇
药学   41篇
肿瘤学   52篇
  2023年   19篇
  2022年   5篇
  2021年   19篇
  2020年   9篇
  2019年   10篇
  2018年   17篇
  2017年   16篇
  2016年   17篇
  2015年   20篇
  2014年   20篇
  2013年   30篇
  2012年   46篇
  2011年   41篇
  2010年   29篇
  2009年   21篇
  2008年   39篇
  2007年   34篇
  2006年   28篇
  2005年   17篇
  2004年   23篇
  2003年   18篇
  2002年   17篇
  2001年   2篇
  2000年   4篇
  1999年   8篇
  1998年   6篇
  1997年   6篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   4篇
  1992年   2篇
  1991年   4篇
  1990年   2篇
  1989年   2篇
  1987年   3篇
  1986年   2篇
  1984年   4篇
  1983年   2篇
  1979年   4篇
  1978年   2篇
  1975年   3篇
  1974年   2篇
  1973年   6篇
  1972年   2篇
  1971年   2篇
  1970年   3篇
  1968年   2篇
  1966年   4篇
  1910年   1篇
排序方式: 共有591条查询结果,搜索用时 15 毫秒
91.
92.
93.
In the present communication, a simple and efficient synthesis of some new Pyrano-[2,3-c]-pyrazoles derivatives are described by the one-pot condensation of a mixture of 3-methyl-1-phenyl-1H-pyrazole-5(4H)-one, substituted heterylaldehydes and malononitriles in polyethylene glycol (PEG-400) as green reaction solvent, further reacted with substituted acetophenones in the presence of polyethylene glycol (PEG-400) to form naphthalene analogues. Synthesis of novel substituted naphthalene analogues libraries are currently of high interest. The chemical structures of newly synthesized compounds were confirmed by IR, 1H NMR and Mass spectral analysis. In vitro antimycobacterial activities of newly synthesized compounds were investigated against Mycobacterium smegmatis, Mycobacterium pheli and Mycobacterium tuberculosis species. The result revealed that most of the compounds showed good to moderate Antimycobacterial activity.  相似文献   
94.
95.
Nephrocalcinosis, acute calcium oxalate (CaOx) nephropathy, and renal stone disease can lead to inflammation and subsequent renal failure, but the underlying pathological mechanisms remain elusive. Other crystallopathies, such as gout, atherosclerosis, and asbestosis, trigger inflammation and tissue remodeling by inducing IL-1β secretion, leading us to hypothesize that CaOx crystals may induce inflammation in a similar manner. In mice, intrarenal CaOx deposition induced tubular damage, cytokine expression, neutrophil recruitment, and renal failure. We found that CaOx crystals activated murine renal DCs to secrete IL-1β through a pathway that included NLRP3, ASC, and caspase-1. Despite a similar amount of crystal deposits, intrarenal inflammation, tubular damage, and renal dysfunction were abrogated in mice deficient in MyD88; NLRP3, ASC, and caspase-1; IL-1R; or IL-18. Nephropathy was attenuated by DC depletion, ATP depletion, or therapeutic IL-1 antagonism. These data demonstrated that CaOx crystals trigger IL-1β–dependent innate immunity via the NLRP3/ASC/caspase-1 axis in intrarenal mononuclear phagocytes and directly damage tubular cells, leading to the release of the NLRP3 agonist ATP. Furthermore, these results suggest that IL-1β blockade may prevent renal damage in nephrocalcinosis.  相似文献   
96.
Acquired clonal chromosome X aberrations, whether numerical or structural, as the sole chromosomal anomaly in acute myeloid leukemia (AML) are very uncommon. The scarcity of nonconstitutional chromosome X aberrations detected in AML has prevented any meaningful evaluation of their prognostic significance. In this report, we describe the case of a patient with AML who had the unusual acquired karyotype of 45,X/-X,46,X,i(X)(q10) on presentation and 45,X,-X,add(19)(p13.3) on relapse. We also briefly review the literature on acquired numerical and structural chromosome X aberrations as the sole chromosomal anomaly in AML. This case adds to the sparse body of literature regarding chromosome X aberrations in AML. More case reports are needed to further elucidate the importance of such aberrations.  相似文献   
97.
Efficacy and safety of 2 herbal products--E-MA-H at 2 dose levels, low (HLD) and high (HHD), and E-MA-HP (HP) capsules--versus placebo (PL) was evaluated in subjects with male sexual dysfunction. Males aged 21-60 with erectile dysfunction, premature ejaculation, or other form of sexual dysfunction were studied in this triple-blind, randomized, placebo-controlled, parallel-groups trial. Subjects received any one of the following 4 interventions: E-MA-H 2 capsules at night (HLD) for 60 days; E-MA-H 2 capsules twice daily for 30 days, followed by 2 capsules at night for 30 days (HHD); E-MA-HP (HP) 2 capsules twice daily for 60 days; or placebo (PL) 2 capsules twice daily for 60 days. All dosage regimens were standardized to 2 capsules twice daily by using 2 matching placebo capsules as the morning dose for HLD and on days 31-60 for HHD. Efficacy outcome measures were the international index of erectile function; index for premature ejaculation; erectile dysfunction inventory of treatment satisfaction; subjects' and investigators' global assessment. Safety was assessed through adverse events; hematology; blood chemistry. Of 148 subjects enrolled, 1 was excluded from analysis; data on the intention-to-treat population of 147 (PL = 36, HLD = 38, HHD = 37, HP = 36) were analyzed. There was a significant (P < 0.01) increase in the total international index of erectile function score (mean ± SEM) in subjects receiving HLD (16.28 ± 1.39), HHD (15.40 ± 1.22), and HP (18.55 ± 1.36) compared with PL (6.83 ± 1.52). The same pattern was seen with increase in index for premature ejaculation scores: HLD (9.68 ± 1.17), HHD (10.27 ± 1.05), HP (11.36 ± 1.20) versus PL (3.77 ± 1.04). There was no significant difference in effect among the active treatment groups. The incidence of adverse events was similar in all the groups. Laboratory evaluations did not show any clinically significant abnormality in any of the groups. Treatment with HLD, HHD, and HP is well tolerated, and more effective than placebo (P < 0.01), in subjects with erectile dysfunction, premature ejaculation, and other forms of sexual dysfunction.  相似文献   
98.
Aging in humans is associated with parallel changes in cognition, motivation, and motoric performance. Based on the human aging literature, we hypothesized that this constellation of age-related changes is mediated by the medial prefrontal cortex and that it would be observed in aging mice. Toward this end, we performed detailed assessments of cognition, motivation, and motoric behavior in aging mice. We assessed behavioral and cognitive performance in C57Bl/6 mice aged 6, 18, and 24 months, and followed this with microarray analysis of tissue from the medial prefrontal cortex and analysis of serum cytokine levels. Multivariate modeling of these data suggested that the age-related changes in cognition, motivation, motor performance, and prefrontal immune gene expression were highly correlated. Peripheral cytokine levels were also correlated with these variables, but less strongly than measures of prefrontal immune gene upregulation. To determine whether the observed immune gene expression changes were due to prefrontal microglial cells, we isolated CD11b-positive cells from the prefrontal cortex and subject them to next-generation RNA sequencing. Many of the immune changes present in whole medial prefrontal cortex were enriched in this cell population. These data suggest that, as in humans, cognition, motivation, and motoric performance in the mouse change together with age and are strongly associated with CNS immune gene upregulation.  相似文献   
99.
Neuroacanthocytoses are neurodegenerative disorders marked by phenotypic and genetic heterogeneity. There are several associated genetic loci, and many defects, including gene deletions and insertions, and missense, nonsense, and splicing mutations, have been found spread over hundreds of kilobases of genomic DNA. In some cases, specific diagnosis is unclear, particularly in the early stages of disease or when there is an atypical presentation. Determination of the precise genetic defect allows assignment of the diagnosis and permits carrier detection and genetic counseling. The objective of this report was to utilize exome sequencing for genetic diagnosis in the neuroacanthocytosis syndromes. Genomic DNA from 2 patients with clinical features of chorea-acanthocytosis was subjected to targeted exon capture. Captured DNA was subjected to ultrahigh throughput next-generation sequencing. Sequencing data were assembled, filtered against known human variant genetic databases, and results were analyzed. Both patients were compound heterozygotes for mutations in the VPS13A gene, the gene associated with chorea-acanthocytosis. Patient 1 had a 4-bp deletion that removes the 5' donor splice site of exon 58 and a nucleotide substitution that disrupts the 5' donor splice site of exon 70. Patient 2 had a dinucleotide deletion in exon 16 and a dinucleotide insertion in exon 33. No mutations were identified in the XK, PANK2, or JPH3 gene loci. Exome sequencing is a valuable diagnostic tool in the neuroacanthocytosis syndromes. These studies may provide a better understanding of the function of the associated proteins and provide insight into the pathogenesis of these disorders.  相似文献   
100.
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