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   4081篇
  免费   221篇
  国内免费   47篇
耳鼻咽喉   35篇
儿科学   55篇
妇产科学   110篇
基础医学   697篇
口腔科学   28篇
临床医学   305篇
内科学   666篇
皮肤病学   234篇
神经病学   284篇
特种医学   190篇
外科学   646篇
综合类   34篇
预防医学   226篇
眼科学   75篇
药学   371篇
中国医学   72篇
肿瘤学   321篇
  2023年   20篇
  2022年   61篇
  2021年   118篇
  2020年   50篇
  2019年   90篇
  2018年   100篇
  2017年   77篇
  2016年   101篇
  2015年   184篇
  2014年   196篇
  2013年   223篇
  2012年   362篇
  2011年   308篇
  2010年   195篇
  2009年   173篇
  2008年   210篇
  2007年   200篇
  2006年   205篇
  2005年   215篇
  2004年   159篇
  2003年   160篇
  2002年   147篇
  2001年   67篇
  2000年   50篇
  1999年   76篇
  1998年   38篇
  1997年   22篇
  1996年   23篇
  1995年   15篇
  1994年   13篇
  1993年   18篇
  1992年   36篇
  1991年   42篇
  1990年   49篇
  1989年   49篇
  1988年   36篇
  1987年   42篇
  1986年   21篇
  1985年   15篇
  1984年   17篇
  1983年   15篇
  1982年   13篇
  1981年   9篇
  1979年   8篇
  1978年   9篇
  1975年   12篇
  1974年   13篇
  1972年   12篇
  1971年   12篇
  1969年   8篇
排序方式: 共有4349条查询结果,搜索用时 263 毫秒
1.
AimsTo demonstrate a new laparoscopic sign “Sharma's Parachute sign” in abdominopelvic tuberculosis in women with infertility.MethodsA total of 104 women who were diagnosed to have abdominopelvic tuberculosis, on endometrial sampling or on laparoscopy were enrolled in this ongoing study on tuberculosis in infertility. A new laparoscopic “Sharma's parachute sign” was looked for in these cases on laparoscopy.ResultsThe mean age, pairty and duration of infertility was 27.6 years, 0.58 and 4.1 years respectively. Menstrual dysfuction were common especially hypomenorrhoea (34.61%), oligomenorrhoea (36.53%) along with constitutional symptoms and abdomino pelvic pain or lump. Diagnosis of abdominopelvic tuberculosis was made by identification of acid fast bacilli (AFB) on microscopy or culture of endometrial aspirate or peritoneal biopsy or positive gene Xpert or positive polymerase chain reaction (PCR) or histopathological demonstration of epithelioid granuloma on endometrial or peritoneal biopsy, various laparoscopic findings on pelvic and abdominal organs were tubercles and shaggy areas (white deposits, caseous nodules encysted ascites, abdominal and pelvic adhesions, tubal findings (hydrosalpinx, pyosalpinx, beaded or calcified tubes). A new “Sharma's parachute sign”in which ascending colon was totally adherent to anterior abdominal wall with its mesocolon looking like an open parachute with small caseous nodule was seen in 11 (10.5%) cases.ConclusionDiagnostic laparoscopy is an important investigation for abdominopelvic tuberculosis showing various adhesions including new parachute sign.  相似文献   
2.
3.
Purpose:To evaluate the rate of compliance and the reasons for loss to follow-up in Indian patients with diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) being treated with anti-vascular endothelial growth factor (VEGF) therapy.Methods:This was a retrospective single-center study. Patients with DME, AMD, or RVO were eligible if they initiated anti-VEGF therapy between January 2013 and December 2017. Patients'' data were obtained from hospital electronic records, including the number of injections received, visits, details of follow-up, missed appointments, and reasons for loss to follow-up (>365 days).Results:A total of 648 patients were eligible for the study, of which 334 (51.54%) patients were lost to follow-up. Overall, 343 (64.96%) were males and the overall mean (SD) age was 66.40 (7.44) years. A total of 376 (58.0%) patients had a history of diabetes and 364 (56.2%) patients had a history of hypertension. Further, 127 (38.0), 112 (33.5), and 95 (28.4) had DME, AMD, and RVO, respectively and were lost to follow-up. The most commonly reported reason for loss to follow-up was “non-affordability” (n = 120; 41.1%) followed by “no improvement in vision” (n = 83; 28.4%). “No improvement in vision” (42.2%) and “non-affordability” (37.5%) were higher among patients with DME. No association was found in gender- and treatment-wise distribution of reasons for loss to follow-up.Conclusion:The results showed that around half of the patients with DME, AMD, and RVO were lost to follow-up to intravitreal anti-VEGF therapy, and the most common factors were “non-affordability” and “no improvement in vision.”  相似文献   
4.
Many studies have recently reported on laparoscopic liver resection, although its development has been slow compared to laparoscopy in other fields. The indications for the location of laparoscopic liver resection have previously been limited to easily accessible lesions. Performing laparoscopic liver resection in the posterior and superior parts of the liver has been considered difficult due to inadequate exposure, the poor operative field and the difficulty with parenchymal dissection. Flexible endoscopy, high definition imaging and various kinds of equipment for parenchymal transection have been introduced for clinical use. In addition, much experience with this procedure has been accumulated at many centers. Accordingly, there are an increasing number of reports on laparoscopic liver resection in difficult locations. At our institution, the location of the tumor is no longer a limitation to laparoscopic liver resection. However, for safer laparoscopic liver resection, the patient positioning and trocar placement should be individualized according to the tumor location. The type of resection also may depend on the remaining liver’s functional capacity. We describe here the technical considerations for performing laparoscopic liver resection, including the technical considerations for performing laparoscopic liver resection for lesions located in the postero-superior segments of the liver.  相似文献   
5.
The authors describe a very rare case of choreoathetotic movements which appeared in an epileptic in strict relationship to a toxic concentration of diphenylhydantoin in the serum. These movements were reversible and disappeared after reduction of drug dose and its serum concentration falling to the therapeutic range.  相似文献   
6.
Torsion of greater omentum is a rare cause of acute abdomen. However, it should be included in the differential diagnoses in addition to acute cholecystitis, acute appendicitis, cecal diverticulitis, and other variable causes of acute abdomen. Diagnosis is usually made at laparotomy for suspected appendicitis. In some cases, computed tomography demonstrates a successful preoperative detection of omental torsion. We report a case of surgically and pathologically proven torsion with subsequent infarction of greater omentum presented as an acute abdominal pain.  相似文献   
7.
Muscularis mucosa of urinary bladder. Importance for staging and treatment   总被引:1,自引:0,他引:1  
We report the results of a histologic evaluation of muscle (muscularis mucosa) in the lamina propria of the urinary bladder performed on 100 consecutive cystectomy specimens. Muscle fibers were found in the lamina propria lying parallel to the mucosa and forming a distinct muscularis mucosa in three cases; they were interrupted or discontinuous in 20 cases, and dispersed or scattered, forming thin bundles, in 71 cases. In six cases, there were no muscle fibers in the lamina propria. In addition, we noticed that the lamina propria contains large vessels that run along the length of the lamina propria in a continuous or interrupted fashion. When muscle fibers are present, they are associated with these vessels. Since prognosis and management of muscle invasive carcinomas (stage B) is different from that of lamina propria-invasive tumors (stage A), pathologists and urologists should be aware of the presence of a muscularis mucosa in the urinary bladder.  相似文献   
8.
Hemoperitoneum secondary to rupture of cystic artery pseudoaneurysm   总被引:1,自引:0,他引:1  
BACKGROUND:Spontaneous hemoperitoneum of hepato- biliary origin is commonly due to hemorrhage from a liver tumor.It is rarely caused by spontaneous rupture of aneurysm in visceral arteries. METHODS:We report an unusual case of hemoperitoneum caused by rupture of cystic artery pseudoaneurysm,and also outline the approach to its management through surgical and radiological methods. RESULTS:In our patient,the pseudoanurysm was initially treated with percutaneous thrombin injection.However this method of treatment failed after initial success.The pseudoanurysm was finally obliterated successfully using microcoil embolization. CONCLUSIONS:The mainstay of treatment of cystic artery pseudoaneurysm is cholecystectomy and ligation of the aneurysm.Recent publications showed success in using microcoil embolisation.In this case we also outline the use of percutaneous thrombin injection as a definitive treatment method and discuss its success or failure as a new method of treatment.  相似文献   
9.
BACKGROUND: The clinical behavior of the tumor in patients with locally advanced bladder carcinoma is unpredictable. Current predictors of clinical behavior include depth of muscle invasion, presence of vascular invasion, proliferation rate, and loss of blood group antigens. Treatment selection would be facilitated by the development of a reliable marker of tumor progression. Functional retinoblastoma (RB) gene loss has been reported to occur in bladder carcinoma, but the significance of this loss is unknown. PURPOSE: We have evaluated the frequency of functional loss of the RB gene in locally advanced bladder carcinoma and have compared the results to known prognostic factors in the same cohort. METHODS: Forty-three study patients with pathologically well-characterized, locally advanced bladder carcinoma, who were placed in a protocol incorporating surgery and chemotherapy, were studied for known clinical and pathological prognostic indicators as well as for their Rb status. Formalin-fixed and paraffin-embedded archival primary tumor tissues were used for histological and immunohistochemical analyses. RESULTS: Altered Rb protein expression was documented in 37% of the tumor specimens. The high rate of altered Rb expression found in this cohort with advanced urothelial tumors strongly suggests that RB functional loss may be associated with tumor progression in this malignancy. Altered Rb protein expression was found to be independent of other known prognostic variables. A significantly poorer tumor-free survival rate also was noted for those patients who had a tumor with an altered Rb protein with or without vascular invasion. CONCLUSION: The high frequency of Rb alteration in locally advanced bladder carcinomas, plus the fact that a significant correlation could not be found between the Rb status and other known prognostic markers in this preliminary study, suggests that altered RB expression may be an independent prognostic marker of tumor progression in bladder cancer.  相似文献   
10.
Renal cell carcinoma is unpredictable in outcome, although the best predictor is tumor stage, followed by histologic grade. The authors retrospectively assessed the clinicopathologic features and DNA ploidy of 103 cases of renal cell carcinoma, the latter determined by flow cytometry of formalin-fixed, paraffin-embedded tissue. The study group comprised 63 men and 40 women (age, 28-80 years; mean, 57 years). Robson stage at diagnosis was Stage I in 52 patients, Stage II in 21, and Stage III in 30. Statistically significant variables in predicting outcome were Robson stage (P less than 0.0001), DNA ploidy (P = 0.0008), mitotic rate (MR, P less than 0.0001), worst nuclear grade (WNG, P = 0.00009), predominant nuclear grade (P = 0.019), and sex (P = 0.044). Tumor size, cell type, and architectural pattern were also assessed but did not prove to be significant. Statistically significant associations occurred between DNA ploidy and WNG (P less than 0.0001), stage (P = 0.0037), and MR (P = 0.015); between WNG and MR (P less than 0.0001) and stage (P = 0.0007); and between stage and MR (P = 0.002). Cox proportional hazards regression analysis of all significant variables showed Robson stage, tumor ploidy, and MR to be independent, significant predictors of outcome. If ploidy data had not been available, WNG would have been independently significant. The authors conclude that DNA ploidy analysis provides significant predictive information on renal cell carcinoma.  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