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   826篇
  免费   59篇
  国内免费   8篇
耳鼻咽喉   37篇
儿科学   16篇
妇产科学   11篇
基础医学   134篇
口腔科学   81篇
临床医学   46篇
内科学   173篇
皮肤病学   15篇
神经病学   46篇
特种医学   29篇
外科学   119篇
综合类   2篇
预防医学   29篇
眼科学   9篇
药学   32篇
中国医学   1篇
肿瘤学   113篇
  2023年   7篇
  2022年   4篇
  2021年   17篇
  2020年   9篇
  2019年   15篇
  2018年   24篇
  2017年   24篇
  2016年   29篇
  2015年   28篇
  2014年   35篇
  2013年   49篇
  2012年   54篇
  2011年   53篇
  2010年   38篇
  2009年   19篇
  2008年   40篇
  2007年   59篇
  2006年   46篇
  2005年   53篇
  2004年   41篇
  2003年   44篇
  2002年   27篇
  2001年   14篇
  2000年   15篇
  1999年   15篇
  1998年   16篇
  1997年   7篇
  1996年   7篇
  1995年   3篇
  1994年   4篇
  1993年   5篇
  1992年   9篇
  1991年   8篇
  1990年   6篇
  1989年   9篇
  1988年   12篇
  1987年   4篇
  1986年   5篇
  1985年   7篇
  1984年   2篇
  1982年   4篇
  1981年   2篇
  1974年   4篇
  1973年   5篇
  1972年   3篇
  1970年   1篇
  1969年   2篇
  1968年   2篇
  1966年   1篇
  1965年   1篇
排序方式: 共有893条查询结果,搜索用时 31 毫秒
1.
Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).  相似文献   

2.
3.
To evaluate the biological reactions to metal ions potentially released from prosthetic implants, we examined the ability of metal ions to produce bone-resorbing cytokines and the underlying mechanism using synoviocytes and bone marrow (BM) macrophages. The cells were incubated with NiCl(2), CoCl(2), CrCl(3) or Fe(2)(SO(4))(3) at optimal concentrations, which are detectable in joint fluid following total joint arthroplasty. The production of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha were enhanced by all metal ions tested as determined by enzyme-linked immunosorbent assay. From the results of electrophoresis mobility shift assay, all metal ions enhanced the DNA-binding activity of nuclear factor kappaB (NF-kappaB), and p50-p65 heterodimers and p50 homodimers were the major subunits. These effects of the metal ions were considerably blocked by pyrrolidine dithiocarbamate (PDTC) known as a radical scavenger. An electron spin resonance study clearly demonstrated the ability of metal ions to generate activated oxygen species (AOS), especially hydroxyl radicals (*OH), which accounts for PDTC-blockade of metal ion-induced NF-kappaB activation and subsequent cytokine production. Taken together, our data raised the possibility that small amounts of metal ions released from prosthetic implants activate synoviocytes and BM macrophages through the AOS-mediated process (i.e. the redox pathway), and contribute to the initiation of osteolysis at the bone-implant interface.  相似文献   
4.
The correlation between lipid peroxidation and morphologic changes was examined in Sprague-Dawley rat lungs after 30 Gy single thoracic radiation. The rats were sacrificed every week until the end of the fifth week after radiation. The left lungs were used for the measurement of lipid peroxides and antioxidant enzymes activities. The right lungs were examined by light and electron microscopy. Amounts of lung lipid peroxides were within normal limits, and no cellular degenerative changes were observed in the lungs except for subendothelial and interstitial edema 2 weeks after radiation. Lipid peroxides drastically increased and marked degenerative cellular changes such as edematous swelling, vacuolation, and destruction of cell membranes occurred in the alveolar septa following the third week after radiation. The activities of catalase were significantly higher during the period from the second to the fifth week and those of superoxide dismutase and glutathione peroxidase increased at the end of the fifth week. Our results demonstrated that the acceleration of lipid peroxidation was well correlated with the morphologic expression of cell injury in the irradiated lungs.  相似文献   
5.
For evaluation of the degree of senescence in SAM-P, accelerated senescence prone mouse, formerly called SAM or prone series or P-series, consisting of SAM-P/1, SAM-P/2, SAM-P/3 and SAM-P/4 corresponding to P-1, P-2, P-3 and P-4 series, respectively, in the previous reports, and in SAM-R, accelerated senescence resistant mouse, formerly called resistant series or R-series, consisting of SAM-R/1, SAM-R/2 and SAM-R/3 corresponding to R-1, R-2 and R-3 series, respectively, in the previous reports, the grading score system was adopted. The items to be examined in this system include 11 categories selected from the clinical signs and gross lesions considered to be associated with the aging process. The degree of the senescence in each category was graded from 0 to 4 according to the detailed criteria devised in our laboratory. After 8 months of age each mouse was examined every 4 months, and some of the mice were examined after 2 months of age.In almost all categories, the grading score and incidence began to increase from 4 or 6 months of age and continued to increase with advancing age in both SAM-P and SAM-R. The increase, however, was more marked in SAM-P than in SAM-R. The slow but steady increase in the SAM-R levelled out at 24 months of age and was comparable to that of 12 months of age in SAM-P. In both SAM-P/1 at 8 months of age and SAM-R/2 at 12 months of age, there was a significant reverse correlation between total score of this grading score system and length of residual life after examination.Systematic and extensive studies using the grading score system showed that if the validity of the system is, based on “irreversibility” and “universality” of the changes in  相似文献   
6.
The incidence and factors associated with multiple primary cancer were surveyed and analyzed from April 1978 through December 1990 in our clinic. Fifty-nine cases with multiple primary cancers were selected for study from among 579 cases with malignant head and neck region tumors. The cancers involved the larynx in 17 cases (8.4%), oral cavity in 14 (19.4%), oropharynx in 13 (41.9%), hypopharynx in 7 (8.0%) and nasal cavity or paranasal sinus in 7 (8.0%). Twenty-one cases (35.6%) arose synchronously within one year. From our observations, heavy drinking and smoking were most strongly suspected to be risk factors for induction of malignancy. Most multiple primary cancers in the head and neck region were observed to coexistent in a "so called multicentric zone" consisting of the oral area, pharyngeal area, larynx, esophagus, stomach, and tracheobronchial tree. To avoid overlooking concealed cancer in the multicentric zone, upper gastro-intestinal endoscopy, bronchial endoscopy, chest X-ray and sputum examination should be performed for screening of patients with head and neck malignancies.  相似文献   
7.
8.
9.
We present a set of nuclear DNA SNPs useful for discriminating native Lake Biwa and introduced ??Eurasian?? strains of common carp, and further, for detecting their hybridization. Such SNPs were searched around short tandem repeat (STR) regions to be used later as HapSTR markers. A total of 62 microsatellite locus were screened with PCR and direct sequencing. The resultant nucleotide sequences from typical Lake Biwa (n?=?30) and ??Eurasian?? (n?=?24) specimens indicated that a total of 21 SNPs distributed across 7 loci would be useful for the above-mentioned purpose. All of the SNPs can be genotyped by direct sequencing, simultaneously with STR polymorphisms.  相似文献   
10.
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