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   1316篇
  免费   72篇
  国内免费   7篇
耳鼻咽喉   17篇
儿科学   142篇
妇产科学   41篇
基础医学   137篇
口腔科学   87篇
临床医学   89篇
内科学   306篇
皮肤病学   19篇
神经病学   85篇
特种医学   36篇
外科学   248篇
综合类   9篇
预防医学   41篇
眼科学   30篇
药学   43篇
中国医学   5篇
肿瘤学   60篇
  2024年   6篇
  2023年   37篇
  2022年   50篇
  2021年   79篇
  2020年   48篇
  2019年   56篇
  2018年   55篇
  2017年   36篇
  2016年   64篇
  2015年   47篇
  2014年   54篇
  2013年   47篇
  2012年   61篇
  2011年   64篇
  2010年   46篇
  2009年   36篇
  2008年   60篇
  2007年   78篇
  2006年   70篇
  2005年   70篇
  2004年   53篇
  2003年   44篇
  2002年   43篇
  2001年   44篇
  2000年   45篇
  1999年   22篇
  1998年   7篇
  1997年   8篇
  1996年   3篇
  1995年   2篇
  1994年   4篇
  1993年   2篇
  1992年   15篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1988年   5篇
  1987年   3篇
  1986年   3篇
  1984年   5篇
  1982年   1篇
  1978年   1篇
  1975年   1篇
  1971年   2篇
  1967年   2篇
  1966年   4篇
排序方式: 共有1395条查询结果,搜索用时 15 毫秒
1.
Aging alters bladder functions where a decrease in filling, storage and emptying is observed. These changes cause urinary incontinence, especially in women. The aim of this study is to examine how aging affects the intracellular calcium movements due to agonist-induced contractions in permeabilized female rat bladder. Urinary bladder isolated from young and old female Sprague-Dawley rats were used. Small detrusor strips were permeabilized with β-escin. The contractile responses induced with agonists were compared between young and old groups. Carbachol-induced contractions were decreased in permeabilized detrusor from old rats compared to young group. Heparin and ryanodine decreased carbachol-induced contractions in young rats where only heparin inhibited these contractions in olds. Caffeine-induced contractions but not inositol triphosphate (IP3)-induced contractions were decreased in old group compared to youngs. The cumulative calcium response curves (pCa 8–4) were also decreased in old rats. Carbachol-induced calcium sensitization responses did not alter by age where GTP-β-S and GF-109203X but not Y-27632 inhibited these responses. Carbachol-induced contractions decrease with aging in rat bladder detrusor. It can be postulated as IP3-induced calcium release (IICR) is primarily responsible for the contractions in older rats where the decrease in carbachol contractions in aging may be as a result of a decrease in calcium-induced calcium release (CICR), rather than carbachol-induced calcium sensitization.  相似文献   
2.
Perineal testicular ectopia is seen very rarely, bilaterality is even more scarce and three cases have been reported in the literature. Here we present the fourth case with bilateral perineal ectopic testes.  相似文献   
3.
4.
5.
Neuroleptic malignant syndrome (NMS) is the rarest and most serious of the neuroleptic-induced movement disorders. We describe a case of neuroleptic malignant syndrome (NMS) associated with the use of ziprasidone. Although conventional neuroleptics are more frequently associated with NMS, atypical antipsychotic drugs like ziprasidone may also be a cause. The patient is a 24-year-old male with a history of schizophrenia who developed signs and symptoms of NMS after 2 days of treatment with an 80-mg/day dose of orally administrated ziprasidone. This case is the earliest (second day of treatment) NMS due to ziprasidone reported in the literature.  相似文献   
6.
OBJECTIVE: The aim of the study was to examine the dose enhancement from scattered radiation at bone-dental implant interfaces during simulated head and neck radiotherapy. STUDY DESIGN: Four cylindrical titanium dental implants with 3 different sizes and lengths were implanted into a human mandible in 4 different positions. Ionization measurements for 6 MV X, 25 MV X, and Co-60 gamma rays were done. Thermoluminescent dosimeter (TLD 100 ) chips were used to measure radiation dose enhancement due to the scattered electrons from titanium and electronic disequilibrium at the tissue-metal interface. RESULTS: The results showed that for Co-60, there is a 21% maximum increase in dose to alveolar mandibular bone at the close proximity to the titanium. For 6-MV x-rays the dose enhancement increase was almost the same or slightly lower than for Co-60, while for 25-MV high-energy x-rays, dose enhancement was lower than that of others. This increase in dose enhancement fell off rapidly and became insignificant at 2 mm from the interface. CONCLUSION: Total dose that may lead to osteoradionecrosis risk of the mandible is slightly but not significantly affected by the scattered dose of the dental implants of lower jaw in the radiation field exposed to 3 different radiation beams.  相似文献   
7.
8.
The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.  相似文献   
9.
PURPOSE: To define the relation of nonoliguric renal failure to transurethral resection of the prostate (TURP), its clinical importance, and predictive factors. PATIENTS AND METHODS: The files of 439 patients who had undergone TURP at Hacettepe University School of Medicine, Department of Urology, between January 1991 and 1994 were analyzed. The patients were divided into three groups according to postoperative serum creatinine concentration and the presence of clinical signs and symptoms of TUR syndrome (Group I: patients with preoperative and postoperative creatinine in the normal range; Group II: patients suffering nonoliguric renal failure; and Group III: patients with TUR syndrome). The data of the groups were compared in terms of factors influencing nonoliguric renal failure. RESULTS: The mean postoperative concentrations of sodium, blood urea nitrogen, creatinine, and albumin in Groups II and III were statistically different from those in Group I (P < 0.001). There was a moderate relation between hyponatremia and the occurrence of nonoliguric renal failure (r(s) = -0.56). Capsule perforation increased the risk of nonoliguric renal failure 10.6 fold. All of the patients were managed by a conservative approach, and none of the patients died or progressed to end-stage renal disease. They were all discharged with a mean hospitalization period of 7 days and normal renal function tests. CONCLUSION: Nonoliguric renal failure was thought to be an early step in the pathophysiology of TUR syndrome with acute renal failure. It is an asymptomatic clinical picture that is undiagnosed unless laboratory examinations are performed. A conservative therapeutic approach is enough.  相似文献   
10.
Oge O  Erdem E  Atsü N  ahin A  Ozen H 《European urology》2000,37(3):271-274
OBJECTIVES: The cystoscopic follow-up of superficial bladder cancer accounts for a considerable workload for urologists and is also an invasive procedure with high costs. There is a potential benefit both to the urologist and the patient if unnecessary cystoscopies can be avoided. METHODS: The recurrence and progression rates of 120 patients with pTa G1 or G2 and small (<4 cm) transitional cell carcinoma were evaluated retrospectively. RESULTS: The recurrence rate was 6.5% (8/120) at 3 months. The recurrence rates at 6 and 9 months were 6.7 (8/119) and 3.6% (4/112), respectively. However, when the third month (first check) was clear, the recurrence rates at 6- and 9-month cystoscopy were 4.3 (5/116) and 2.7% (3/111), respectively. The recurrence rate at 12 months was 8% (8/99). For G1 tumors, the recurrence rates at 3, 6, 9 and 12 months were 6 (5/84), 5 (5/83), 2.5 (2/80) and 7% (5/71), respectively. The same results for G2 tumors were 8 (3/36), 8 (3/36), 6 (2/32) and 10.5% (3/28), respectively. The progression rate for the first year was lower than 1%. The difference between G1 and G2 tumors according to recurrence rate within the first year was not statistically significant (p>0. 05). CONCLUSIONS: This study supports the proposal that for patients with small and welldifferentiated pTa tumors at diagnosis, if the first control cystoscopy is clear, it is appropriate to perform the second check cystoscopy 1 year from initial resection and subsequent controls yearly. One should note that the study group included the most suitable patients for cystoscopic follow-up according to size and multiplicity of the tumor. This change in policy is further supported by the fact that progression occured in less than 1% in this group of patients.  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