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   2343篇
  免费   188篇
  国内免费   29篇
耳鼻咽喉   22篇
儿科学   86篇
妇产科学   36篇
基础医学   250篇
口腔科学   47篇
临床医学   277篇
内科学   375篇
皮肤病学   18篇
神经病学   181篇
特种医学   193篇
外国民族医学   1篇
外科学   397篇
综合类   117篇
一般理论   1篇
预防医学   206篇
眼科学   39篇
药学   205篇
中国医学   1篇
肿瘤学   108篇
  2021年   37篇
  2020年   19篇
  2019年   34篇
  2018年   45篇
  2017年   41篇
  2016年   27篇
  2015年   31篇
  2014年   45篇
  2013年   77篇
  2012年   98篇
  2011年   102篇
  2010年   76篇
  2009年   52篇
  2008年   88篇
  2007年   101篇
  2006年   110篇
  2005年   82篇
  2004年   88篇
  2003年   77篇
  2002年   54篇
  2001年   70篇
  2000年   88篇
  1999年   62篇
  1998年   57篇
  1997年   42篇
  1996年   51篇
  1995年   45篇
  1994年   34篇
  1993年   43篇
  1992年   51篇
  1991年   71篇
  1990年   61篇
  1989年   47篇
  1988年   49篇
  1987年   44篇
  1986年   52篇
  1985年   34篇
  1984年   40篇
  1983年   28篇
  1982年   23篇
  1981年   21篇
  1980年   26篇
  1979年   17篇
  1978年   18篇
  1976年   14篇
  1975年   19篇
  1974年   14篇
  1972年   17篇
  1968年   14篇
  1966年   13篇
排序方式: 共有2560条查询结果,搜索用时 15 毫秒
31.
BACKGROUND: Hev b 5 is a potent latex allergen. In this study, we characterize the linear B-cell epitopes for three monoclonal antibodies (mAbs) to Hev b 5. METHODS: The mAbs included 2 IgG1 (6A10, 3G3) and 1 IgG2b (6F6) isotypes. We used SPOTscan analysis with overlapping octapeptides to identify the binding regions for the antibodies and then methionine substitution analysis to further define the critical amino acids (aa) in each epitope. Site-directed mutagenesis was used to selectively eliminate the IgG binding for each epitope and single and multiple mutations were expressed as recombinant GST fusion proteins. Antibody recognition of the mutant proteins was determined by inhibition ELISA. RESULTS: All three mAbs recognized the same aa sequence by SPOTs analysis with slight variations, and this epitope was repeated 3 times in the Hev b 5 sequence; APETEK (63-68), PAEGEK (120-125), and PAEEEK (126-131). Sequential methionine substitution by SPOTsalogue identified K68, E122, and K131 as critical aa in each epitope to change by site-directed mutagenesis. Inhibition ELISA with the mutant proteins indicated that epitope 126-131 was the dominant epitope, but mutation of epitope 120-125 was also required to eliminate mAb reactivity to Hev b 5. The antibodies did not appear to recognize the epitope 63-68 in the recombinant fusion protein. CONCLUSIONS: We identified an immunodominant B-cell epitope in Hev b 5 that is repeated 3 times within the sequence, making Hev b 5 multivalent. Well-characterized monoclonals recognizing repeated epitopes would be a good choice for immunodetection of Hev b 5 in glove extracts where individual epitopes could get altered by the manufacturing process.  相似文献   
32.
Cervical smear results reporting the presence of inflammation are regularly encountered by smeartakers, yet the significance of this finding is not clear. We wished to evaluate whether the presence of inflammation on smear test was associated with a higher incidence of lower genital tract infection. A retrospective review was carried out on women attending our colposcopy unit for their first visit during 2001. Results of 256 women were available for analysis. Evidence of inflammation was found in 9.7% of smears. Genital tract infection was found in 29.2% of women overall. Infection with more than one micro-organism was present in 8.9 percent. Forty eight percent of women having inflammatory changes on smear test had genital tract infection. This compared with 27.3% of women whose smear tests showed no evidence of inflammation. Prevalence of infection with Chlamydia trachomatis, Candida, Bacteroides and Gardnerella vaginalis was higher in the inflammatory smear group. This study shows that women with an inflammatory smear are more likely to harbour genital tract infection than women whose smear shows no evidence of inflammation. Chlamydia infection in particular has long-term fertility consequences through its potential to cause asymptomatic tubal damage: it was present in a substantial proportion of women with inflammation on smear (20%). Screening for lower genital tract infection via high vaginal swab and either intracervical swab or urinary screening for Chlamydia infection should be carried out in all women with smear tests reporting the presence of inflammation.  相似文献   
33.
This short report describes the outcome of 13 renal transplants in 11 children under 5 years of age. Nine (82%) of the 11 recipients are alive; 2 children died with functioning grafts. Approximately 50% of grafts are functioning at 5 years post transplantation. Children with congenital kidney malformations can be successfully managed to transplantation.  相似文献   
34.
35.
Tissue factor (TF) is an integral membrane protein that binds factor VIIa and initiates coagulation. The extracellular domain of TF is responsible for its hemostatic function and by implication in the dysregulation of coagulation, which contributes to death in endotoxemia. The role of the cytoplasmic domain of tissue factor in endotoxemia was studied in mice, which lack the cytoplasmic domain of TF (TF(deltaCT/deltaCT)). These mice develop normally and have normal coagulant function. Following i.p injection with 0.5 mg of lipopolysaccharide (LPS), TF(deltaCT/deltaCT) mice showed significantly greater survival at 24 hours compared to the wt mice (TF(+/+)). The serum levels of TNF-alpha and IL-1beta were significantly lower at 1 hour after LPS injection and IL-6 levels were significantly lower at 24 hours in TF(deltaCT/deltaCT) mice compared to TF(+/+)mice. Neutrophil recruitment into the lung was also significantly reduced in TF(deltaCT/deltaCT) mice. Nuclear extracts from tissues of endotoxemic TF(deltaCT/deltaCT) mice also showed reduced NFkappaB activation. LPS induced leukocyte rolling, adhesion, and transmigration in post-capillary venules assessed by intravital microscopy was also significantly reduced in TF(deltaCT/deltaCT) mice. These results indicate that deletion of the cytoplasmic domain of TF impairs the recruitment and activation of leukocytes and increases survival following endotoxin challenge.  相似文献   
36.
This large Veterans Administration cooperative study sought to identify the ward milieu characteristics of effective psychiatric programs. It was developed as a multivariable, correlational study that involved systematic observations of program characteristics and outcome effectiveness of wards as they operated in their usual manner. Seventy-nine wards in 18 hospitals provided 11,283 patients eligible for follow-up. Eleven treatment characteristics were found to be correlated to patients' community adjustment 3 months after discharge. These characteristics were classified into five general categories: Patient-staff interaction, patient activities, medication practices, ward physical environment, and nursing staff rotation. The major conclusions are: wards do differ in their effectiveness as measured by ratings of patient posthospital adjustment; and treatment characteristics make a difference in program effectiveness as measured by patients' posthospital adjustment.  相似文献   
37.
Summary Twenty three patients with essential hypertension who were uncontrolled on diuretic and/or -receptor antagonist therapy were treated additionally with the vasodilator, pinacidil, in an open study. Significant reduction in mean blood pressure was achieved. Supine and erect systolic and diastolic blood pressure fell by 44/25 mmHg and 37/24 mmHg respectively over the study period of 12 weeks. Side-effects such as dizziness, headache, facial flushing and mild oedema were experienced by 10 patients during the study, all of which were mild and transient and did not require withdrawal from pinacidil therapy. Pinacidil is an effective and well tolerated agent in the treatment of essential hypertension.  相似文献   
38.
W Vaughn  D Hickey  W H Milam  M Soloway 《Urology》1987,29(5):552-554
Radical cystectomy is the optimal treatment for patients with invasive bladder cancer. The presence of a fused pelvic kidney is an uncommon congenital abnormality and when found in a patient with bladder cancer may alter the operative procedure. Herein we report on a patient presenting with invasive bladder cancer and a pelvic "cake" kidney.  相似文献   
39.
40.
Details of a simple radioaerosol generator and delivery system are presented. Aerosol streams of 99mTc-DTPA solution of different distributions were produced. The most useful distribution had an activity median aerodynamic diameter (AMAD) of 0.9 m with a geometric standard deviation of 1.5. This distribution also had more than 96% of aerosol particles with aerodynamic diameter <2 m. The system has been used for patient lung ventilation studies. The aerosol breathing-in period to achieve a satisfactory count rate was 1.8±0.38 min. The radioaerosol images were excellent and comparable to those obtained with 81mKr gas.  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