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   868篇
  免费   103篇
  国内免费   9篇
耳鼻咽喉   6篇
儿科学   72篇
妇产科学   8篇
基础医学   126篇
口腔科学   34篇
临床医学   84篇
内科学   171篇
皮肤病学   25篇
神经病学   28篇
特种医学   132篇
外科学   113篇
综合类   53篇
预防医学   36篇
眼科学   30篇
药学   23篇
中国医学   2篇
肿瘤学   37篇
  2023年   3篇
  2022年   7篇
  2021年   7篇
  2020年   9篇
  2019年   14篇
  2018年   34篇
  2017年   12篇
  2016年   33篇
  2015年   32篇
  2014年   29篇
  2013年   52篇
  2012年   33篇
  2011年   26篇
  2010年   45篇
  2009年   49篇
  2008年   22篇
  2007年   35篇
  2006年   19篇
  2005年   35篇
  2004年   16篇
  2003年   28篇
  2002年   12篇
  2001年   15篇
  2000年   14篇
  1999年   12篇
  1998年   45篇
  1997年   43篇
  1996年   45篇
  1995年   36篇
  1994年   22篇
  1993年   28篇
  1992年   4篇
  1991年   7篇
  1990年   6篇
  1989年   18篇
  1988年   16篇
  1987年   12篇
  1986年   14篇
  1985年   14篇
  1984年   7篇
  1983年   12篇
  1982年   5篇
  1981年   13篇
  1980年   8篇
  1979年   4篇
  1978年   4篇
  1977年   8篇
  1976年   9篇
  1975年   2篇
  1884年   1篇
排序方式: 共有980条查询结果,搜索用时 515 毫秒
1.
BACKGROUND: Staphylococcus aureus-associated peritonitis and catheter exit-site infections (ESIs) are important causes of hospitalization and catheter loss in patients undergoing chronic peritoneal dialysis. Intranasal and topical use of mupirocin has been found to be an effective strategy in decreasing S. aureus-related infectious complications in persons who are carriers of S. aureus; however, there is no consensus regarding the prophylactic use of mupirocin irrespective of carrier status. We aimed to determine the potential effectiveness of application of mupirocin cream at the catheter exit site in preventing ESI and peritonitis irrespective of carrier status in a tropical country such as India. METHODS: This prospective historically controlled study was done in a total of 40 patients. From August 2003, all patients, incident and prevalent, were instructed to apply 2% mupirocin cream daily to the exit site instead of the older practice of povidone-iodine and gauze dressing. Patients were not screened to determine whether they were S. aureus carriers. The infection-related data for 1 year, until July 2004, were compared with the historical control, which was infection-related data for the year preceding the year of mupirocin application. RESULTS: Mean age of the study population was 62 years, with 61.8% being male and 64.3% being diabetic. Local application of mupirocin led to a significant reduction in the incidence density per patient-month of both ESI and peritonitis compared to controls (0.15 vs 0.37 and 0.37 vs 0.67, p = 0.01 for both). This amounted to a relative reduction of 60.5% and 55% respectively. ESI and peritonitis due to S. aureus were also significantly lower in the study group compared to controls (incidence density per patient-month 0.05 vs 0.13 and zero vs 0.17 respectively, p < 0.01 for both). There occurred no catheter removal due to infection-related complications during the study period compared to two during the control period. None of the patients reported a mupirocin-related adverse effect. CONCLUSIONS: Daily application of mupirocin at the exit site is a well-tolerated and effective strategy in reducing the incidence of ESI and peritonitis in a tropical country such as India. It can thus significantly reduce morbidity, catheter loss, and transfer to hemodialysis in peritoneal dialysis patients.  相似文献   
2.
OBJECTIVES: Factors such as limited health-care budget allotment and poor accessibility of the majority of the population to hemodialysis (HD) facilities should favor the use of peritoneal dialysis (PD) in India. However, only 6% of end-stage renal disease patients undergoing dialysis in India are on PD. We undertook this prospective study to evaluate various factors that could contribute to this low rate of use of PD at a tertiary-care state-run hospital in Northern India. METHODS: All the patients who entered our HD or PD program from August 2001 to December 2003 were interviewed using a preset questionnaire. The questionnaire recorded their basic disease and comorbidity, social and demographic characteristics, awareness of the various modalities of renal replacement therapy (RRT), and the reasons for choosing their present modality of therapy. Treating nephrologists were also interviewed with respect to the factors that, in their opinion, were responsible for the limited use of PD at our institute. RESULTS: In total, 342 patients on HD, 66 patients on PD, and 24 nephrologists were interviewed. The rate of PD use was 16.2%. Mean age of patients on HD and PD was 34.6 +/- 11.8 years and 62.9 +/- 10.3 years respectively (p < 0.0001). The incidence of diabetes mellitus and coronary artery disease in the HD and PD populations was 2.5% and 62.5%, and 9.1% and 46.7% respectively (p < 0.0001 for both). Only 30.4% of patients on HD were aware of PD as a modality of RRT and 83.6% of them found PD to be expensive, 65.4% had low enthusiasm toward a domiciliary therapy such as PD, and 61.5% were not recommended PD by their nephrologist. Only 5 (7.6%) patients were initiated on PD directly, the remaining 61 patients were shifted from HD after a mean duration on HD of 185.3 +/- 15.4 days: 67.1% were shifted due to poor tolerance of HD, 29.4% were advised to shift to PD because of comorbidity and vascular access problems, and only 3.3% took up PD because of the independent lifestyle it offered. None of the interviewed nephrologists routinely discussed PD in predialysis counseling. They found financial constraints (100%), lack of patient enthusiasm (100%), doubtful patient compliance (83.2%), and lack of an organized PD program (79.2%) to be the main factors limiting more widespread use of PD at our institute. CONCLUSIONS: Peritoneal dialysis is an underused modality of RRT at our institute. The patients who are taken up for PD at our institute are elderly and have a higher incidence of other comorbid conditions, such as diabetes mellitus and coronary artery disease. Also, most patients who switch to PD do so due to their unsuitability for HD rather than by their own choice. The factors contributing to this low rate of use of PD are ignorance of PD, increased cost of therapy, low enthusiasm toward domiciliary therapy, and lack of adequate infrastructure for PD at our institute. Effective predialysis counseling, reduction in the cost of the therapy, and development of an adequate infrastructure can increase the rate of use of PD.  相似文献   
3.
4.
5.
6.
The aim of the study was to determine whether a prior diagnostic testicle biopsy can predict success or failure of testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI) in patients with non-obstructive azoospermia caused by testicular failure, and what is the minimum threshold of sperm production in the testis which must be surpassed for spermatozoa to reach the ejaculate. Forty- five patients with non-obstructive azoospermia caused by testicular failure underwent diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure. The diagnostic testicle biopsy was analysed quantitatively, and correlated with the quantitative findings of spermatogenesis in patients with normal spermatogenesis, as well as with the results of subsequent attempts at TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure had a mean of 0-6 mature spermatids/seminiferous tubule seen on a diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in men with normal spermatogenesis and obstructive azoospermia. These findings were the same for all types of testicular failure whether Sertoli cell only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia. Twenty-two of 26 men with mature spermatids found in the prior testis biopsy had successful retrieval of spermatozoa for ICSI, 12 of their partners became pregnant, and are either ongoing or delivered. The study suggests that 4-6 mature spermatids/tubule must be present in the testis biopsy for any spermatozoa to reach the ejaculate. More than half of azoospermic patients with germinal failure have minute foci of spermatogenesis which are insufficient to produce spermatozoa in the ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for the presence of mature spermatids) can predict subsequent success or failure with TESE-ICSI. Incomplete testicular failure may involve a sparse multi-focal distribution of spermatogenesis throughout the entire testicle, rather than a regional distribution. Therefore, it is possible that massive testicular sampling from many different regions of the testes may not be necessary for successful TESE-ICSI.   相似文献   
7.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis.  相似文献   
8.
The dominant cone-rod dystrophy gene CORD6 has previously been mapped to within an 8 cM interval on chromosome 17p12-p13. The retinal- specific guanylate cyclase gene (RETGC-1), which maps to within this genetic interval and previously was implicated in Leber's congenital amaurosis, was screened for mutations within this family and in a panel of small families and individuals with various cone and cone- rod dystrophy phenotypes. A missense mutation (E837D) was identified in affected members of the CORD6 family, as well as a second missense mutation (R838C) in three other families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene to be implicated in cone-rod dystrophy and this is the first report of dominant mutations in this gene.   相似文献   
9.
In human in-vitro fertilization (IVF), the oocytes are surrounded by cumulus and corona cells at the time of insemination so that their maturity cannot easily be evaluated. The best IVF results are obtained if the oocytes are inseminated 2-6 h after retrieval. In the intracytoplasmic sperm injection (ICSI) procedure, the oocytes are denuded by enzymatic and mechanical treatment in order to be able to perform the injection. As a consequence, the nuclear maturity of the oocytes can be evaluated and only those that have extruded the first polar body are injected. However, metaphase-II oocytes that have not yet reached cytoplasmic maturity cannot be recognized. The purpose of this study was to investigate the effect of different timing of cumulus- corona cell removal and injection on the outcome of ICSI. For this we allowed the oocytes to complete in-vitro cytoplasmic maturation in two different culture conditions: (i) surrounded by their cumulus and corona cells or (ii) totally denuded. We performed three different studies on sibling oocytes obtained after a standardized buserelin/human menopausal gonadotrophin (HMG) protocol. We investigated the effect of early (1-2 h after retrieval) and late (5-6 h after retrieval) oocyte denudation and injection on the survival and fertilization of the injected oocytes and on embryo cleavage after fertilization. We found no statistically significant differences between early and late injection, indicating that after a standardized buserelin/HMG protocol the metaphase-II oocytes do not need time for further cytoplasmic maturation. Furthermore, a different timing of cumulus-corona cell removal has no effect on the outcome of ICSI, suggesting that the surrounding cells are not necessary for survival, fertilization and cleavage after ICSI.   相似文献   
10.
Serum follicle stimulating hormone (FSH) is routinely measured when evaluating the infertile male for intracytoplasmic sperm injection (ICSI). However, among the sperm parameters, only its relationship with sperm concentration is well documented. Few investigations concern the relationship between FSH and sperm motility and morphology, and the results of ICSI. A retrospective study of 316 couples who underwent ICSI was carried out to determine the relationships between serum FSH concentrations in the male and (i) standard sperm parameters_(concentration, motility and morphology) and (ii) fertilization, cleavage, pregnancy and implantation rates after ICSI. There was an inverse correlation with sperm concentration and total motility but no relationship was found with progressive motility and sperm morphology. Neither was any relationship found between serum FSH and fertilization, cleavage, pregnancy and implantation rates, and the results of ICSI. These findings suggest the need to review the routine measurement of serum FSH in the infertile male when ICSI is the planned treatment procedure.   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