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   2400篇
  免费   154篇
  国内免费   11篇
耳鼻咽喉   11篇
儿科学   28篇
妇产科学   73篇
基础医学   273篇
口腔科学   28篇
临床医学   274篇
内科学   659篇
皮肤病学   26篇
神经病学   315篇
特种医学   79篇
外科学   373篇
综合类   7篇
预防医学   82篇
眼科学   19篇
药学   123篇
中国医学   4篇
肿瘤学   191篇
  2023年   19篇
  2022年   34篇
  2021年   63篇
  2020年   41篇
  2019年   61篇
  2018年   58篇
  2017年   62篇
  2016年   57篇
  2015年   55篇
  2014年   94篇
  2013年   120篇
  2012年   164篇
  2011年   162篇
  2010年   102篇
  2009年   90篇
  2008年   159篇
  2007年   139篇
  2006年   117篇
  2005年   122篇
  2004年   113篇
  2003年   110篇
  2002年   109篇
  2001年   49篇
  2000年   58篇
  1999年   44篇
  1998年   28篇
  1997年   17篇
  1996年   20篇
  1995年   18篇
  1994年   12篇
  1993年   10篇
  1992年   26篇
  1991年   24篇
  1990年   17篇
  1989年   14篇
  1988年   22篇
  1987年   11篇
  1986年   11篇
  1985年   10篇
  1984年   13篇
  1983年   10篇
  1982年   7篇
  1980年   7篇
  1979年   8篇
  1978年   6篇
  1977年   8篇
  1975年   7篇
  1973年   8篇
  1969年   8篇
  1968年   9篇
排序方式: 共有2565条查询结果,搜索用时 93 毫秒
91.

Purpose

The purpose of this trial was to evaluate an immunoassay for urinary nuclear matrix protein, NMP22,* as an indicator for transitional cell carcinoma of the urinary tract.

Materials and Methods

Three groups of subjects participated in this trial of NMP22: 1--175 with transitional cell carcinoma, 2--117 with benign urinary tract conditions and 3--375 healthy volunteers. Each subject provided a single (3 voids) urine sample for analysis at the time of study entry. Each sample was assayed for the level of NMP22.

Results

In normal healthy volunteers and in subjects with benign conditions median NMP22 levels were 2.9 and 3.3 units per ml., respectively. Median urinary NMP22 levels in patients with transitional cell carcinoma were significantly greater than in comparison subjects. Patients with active transitional cell carcinoma had significantly greater median urinary NMP22 levels than those with no evidence of disease (6.04 versus 4.11 units per ml., p = 0.027, 1-tailed Mann-Whitney U test). We noted no effect of tumor grade, extent of disease or exposure to intravesical therapy on urinary NMP22 levels.

Conclusions

NMP22 is a promising urinary tumor marker for monitoring transitional cell carcinoma. Nuclear matrix proteins are a new class of tumor markers that represent the basis for the development of assays with increased efficacy for the detection and treatment of cancer.  相似文献   
92.

Background

Survival with long-term follow-up following liver resection for unresectable colorectal liver metastases (CRLM) downsized by chemotherapy has rarely been reported. The aim of this study was to determine the chance of cure following liver resection for initially unresectable CRLM.

Methods

Between January 2000 and December 2009, 61 patients underwent hepatectomy for unresectable liver-only CRLM downsized after chemotherapy. Cure was defined as a recurrence-free interval of at least 5 years after primary hepatectomy.

Results

Resectability of CRLM was achieved after a mean number of 11 courses, and 42.6 % of patients underwent liver resection after ≥10 courses. Postoperative mortality was nil, and morbidity rate was 19.7 %. The 5- and 10-year actuarial overall survival rates were 42.6 and 16.0 %. Of 30 patients with a follow-up ≥5 years, 11 were alive, yielding a 5-year actual overall survival rate of 36.7 %, and 7 (23.3 %) were considered cured because they are alive without recurrence. On multivariate analysis, response to chemotherapy was the only independent predictor of both overall and disease-free survival.

Conclusions

Cure can be achieved in about 23 % of patients resected for initially unresectable CRLM downsized by chemotherapy. Liver resection can be safely performed in selected patients even after multiple courses of chemotherapy.  相似文献   
93.
Objectives  The optimal treatment for large colorectal polyps (LCPs) is still a controversial issue. The aim of this study was to evaluate the safety and effectiveness of endoscopic polypectomy (EP) of colorectal polyps ≥2 cm in size. Patients and methods  One hundred fifty-one EP LCPs were performed over a period of 7 years. Diathermal snare was used for pedunculated and pseudopedunculated polyps and endoscopic mucosal resection (EMR) or biopsy forceps polypectomy for sessile and flat polyps. The resected polyps were recovered and collected for histology. At scheduled follow-up visits 1, 3, 6, and 12 months after polypectomy, complications and recurrences were recorded in all patients. Results  Fifteen polyps were located in the rectum, 84 in the sigmoid colon, 11 in the descending colon, four in the splenic flexure, 11 in the transverse colon, 11 in the hepatic flexure, seven in the ascending colon and eight in the cecum. Fifty-six polyps were sessile, 54 pedunculated, 25 pseudopedunculated, and 16 flat. At histology, most of polyps (131) were adenomas (nine with adenocarcinoma in situ). Five were invasive polypoid carcinomas and required colonic resection. Immediate bleeding occurred in ten patients (7.6%) and it was stopped by endoscopic hemoclips (7), epinephrine injection (1), or surgery (2). There were three perforations (2.3%; all polypoid carcinomas), managed endoscopically (1) or surgically (2). Delayed bleeding occurred in two patients (1.5%) and was treated by endoscopic diathermy and hemoclips (1) or surgery (1). During follow-up, six (4.6%) incompletely excised polyps and three (2.3%) relapses in the site of previous EP were detected and endoscopically removed. Conclusion  EP is relatively safe and effective for benign-appearing LCPs.  相似文献   
94.
95.
96.
97.
The annual incidence of myasthenia gravis (MG) ranges from 3 to 30 per 1,000,000 people. Since the mid-1980s, an increasing incidence has been reported, mainly due to late-onset MG. Whether the increase was due to population aging, improved diagnosis and case collection, or a true excess of incidence cases is still under debate. We used a complete enumeration approach by reviewing all possible sources of case collection in the province of Ferrara, Italy, to estimate the MG incidence and its temporal trend over the study period (1985–2007). The mean annual age-adjusted incidence of MG was 18 per 1,000,000, without any significant temporal trend. The incidence rates in the period 1985–1990 were 14 both for early and late-onset MG. Thereafter, a significant increase in incidence of late-onset MG (p < 0.05), and a decrease in early onset MG were detected (p < 0.01). These findings were related to nonthymoma MG. The median age at onset of the disease steadily increased over time. A changing pattern of MG incidence with an increase in frequency of late-onset and a decrease of early onset MG was found in the last years, giving a significant shift to older age at onset of the disease. Unknown environmental factors may have driven this change in MG epidemiology.  相似文献   
98.
Endometriosis is a chronic gynecological disease characterized by the growth of endometrial tissue outside the uterine cavity. Exposure to endocrine disruptors during critical period of development causes long-lasting effects, being the genital system one of the targets. This study describes the effects on female genital system caused by developmental exposure to the endocrine-disrupting chemical bisphenol A (BPA) during pre- and peri-natal development in mice. To this end, timed pregnant Balb-C mice were treated from day 1 of gestation to 7 days after delivery with BPA (100, or 1000 μg/kg/day). After delivery, pups were held for 3 months; then, pelvic organs were analyzed in their entirety and livers of both pups and moms were studied for the presence of BPA. We found in the adipose tissue surrounding the genital tracts of a consistent number of treated animals, endometriosis-like structure with the presence of both glands and stroma and expressing both estrogen receptor and HOXA-10. Moreover, cystic ovaries, adenomatous hyperplasia with cystic endometrial hyperplasia and atypical hyperplasia were significantly more frequent in treated animals respect to the controls. Finally, BPA was found in the livers of exposed moms and female offspring. In conclusion, we describe for the first time an endometriosis-like phenotype in mice, elicited by pre-natal exposition to BPA. This observation may induce to thoroughly reconsider the pathogenesis and treatment of endometriosis, considering the high incidence of endometriosis and the problems caused by associated infertility.  相似文献   
99.

Menstrually related migraine (MRM) is a particularly difficult-to-treat pain condition, associated with substantial disability. Aim of this study was to compare the efficacy and safety of frovatriptan and zolmitriptan in the treatment of MRM attacks, analyzing data from a multicenter, randomized, double blind, cross-over study. We analyzed the subset of 76 regularly menstruating women who participated in one head-to-head multicenter, randomized, double blind, cross-over clinical trial and who took the study drugs to treat MRM attacks. In a randomized sequence, each patient received frovatriptan 2.5 mg or zolmitriptan 2.5 mg: after treating three episodes of migraine in no more than 3 months with the first treatment, the patient had to switch to the other treatment. MRM was defined according to the criteria listed in the Appendix of the last Classification of Headache disorders of the International Headache Society. A total of 73 attacks, classified as MRM, were treated with frovatriptan and 65 with zolmitriptan. Rate of pain relief at 2 h was 52% for frovatriptan and 53% for zolmitriptan (p = NS), while rate of pain free at 2 h was 22 and 26% (p = NS), respectively. At 24 h, 74 and 83% of frovatriptan-treated and 69 and 82% of zolmitriptan-treated patients were pain free and had pain relief, respectively (p = NS). Recurrence at 24 h was significantly (p < 0.05) lower with frovatriptan (15 vs. 22% zolmitriptan). Frovatriptan proved to be effective in the immediate treatment of MRM attacks, similarly to zolmitriptan, but showed lower recurrence rates, and thus a better sustained relief.

  相似文献   
100.
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