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   5354篇
  免费   276篇
  国内免费   43篇
耳鼻咽喉   20篇
儿科学   141篇
妇产科学   81篇
基础医学   725篇
口腔科学   194篇
临床医学   379篇
内科学   1189篇
皮肤病学   322篇
神经病学   259篇
特种医学   231篇
外科学   692篇
综合类   32篇
预防医学   275篇
眼科学   62篇
药学   376篇
中国医学   11篇
肿瘤学   684篇
  2023年   33篇
  2022年   83篇
  2021年   120篇
  2020年   67篇
  2019年   76篇
  2018年   100篇
  2017年   115篇
  2016年   130篇
  2015年   151篇
  2014年   154篇
  2013年   166篇
  2012年   304篇
  2011年   332篇
  2010年   207篇
  2009年   180篇
  2008年   284篇
  2007年   305篇
  2006年   287篇
  2005年   282篇
  2004年   273篇
  2003年   244篇
  2002年   221篇
  2001年   147篇
  2000年   132篇
  1999年   144篇
  1998年   70篇
  1997年   67篇
  1996年   44篇
  1995年   38篇
  1994年   32篇
  1993年   26篇
  1992年   81篇
  1991年   63篇
  1990年   67篇
  1989年   66篇
  1988年   63篇
  1987年   57篇
  1986年   56篇
  1985年   58篇
  1984年   51篇
  1983年   34篇
  1980年   12篇
  1979年   27篇
  1974年   13篇
  1973年   16篇
  1971年   26篇
  1970年   24篇
  1969年   16篇
  1967年   19篇
  1966年   20篇
排序方式: 共有5673条查询结果,搜索用时 15 毫秒
31.
At the end of the 19th century, surgical treatment of breast cancer was revolutionized by the introduction of the Halsted radical mastectomy. Haagensen, who studied under one of Halsted's students, further strengthened the foundations of the technique, and the Halsted operation became the standard radical breast cancer surgery worldwide. This may have been responsible for the persistence of this operation, particularly in Japan. Some Halstedian surgeons espoused the extended radical mastectomy or super-radical mastectomy. However, breast-conserving surgery is now becoming the most common technique. In the early 1970s breakthroughs in the understanding of the biology of breast cancer led to a new era of adjuvant therapy. Consequently current surgical management of breast cancer is no longer possible without considering other therapeutic modalities. Consistent with this change, it should be realized that the disease is no longer diagnosed at the same stage as it was at the time of Halsted. Although the ultimate patient outcome is not likely to be influenced solely by locoregional treatment, surgery will continue to be employed as the most effective treatment modality, and every effort should be made to prevent locoregional tumor spread.  相似文献   
32.
33.
Background The purpose of this study was to assess the accuracy of contrast-enhanced magnetic resonance imaging (dynamic MR imaging) in the evaluation of preinvasive and early invasive cancer of the cervix. Methods Twenty-nine women with untreated squamous cell carcinoma of the cervix with either no stromal invasion or early stromal invasion underwent pretreatment MR imaging and dynamic MR imaging within 4 weeks of surgical evaluation. The images were evaluated for tumor detection and compared with results of histologic examination of the surgical specimens. Results The lesions in 17 cases with histologically proven stromal invasion of 4 mm or greater were detected with dynamic MR imaging, whereas lesions in only 8 of these cases were detected with T2 imaging. In 9 cases with stromal invasion between 4.0 mm and 5.0 mm, lesions were represented as early phase focal enhancement on dynamic MR images, but not detected on T2-weighted images. In the 12 cases with less than 4 mm stromal invasion, no lesions were visualized on either T2-weighted images or dynamic MR images, except in 1 case of glandular involvement without stromal invasion that appeared as enhancement on early-phase dynamic MR imaging. Conclusion Dynamic MR imaging detected more lesions of early stromal invasion in pretreatment imaging for cervical cancer than nonenhanced MR imaging.  相似文献   
34.
Monoclonal antibodies to adhesive molecules have been used in many trials to decrease ischemia-reperfusion injury, which is considered to occur in areas such as the distal region of the random pattern flap. The monoclonal antibody to the primary neutrophil adherence-mediating glycoprotein CD18 improves the survival length of the random pattern flap. Sulfatide binds strongly with L- and P-selectin. We found that sulfatide has a protective effect against ischemia-reperfusion injury. The purpose of this study was to evaluate the effect of sulfatide on the survival length of the random pattern flap in rats. Sulfatide was administered intravenously just before elevation of the cranially based dorsal skin flap. Administration of sulfatide significantly augmented flap survival length (49.5 +/- 1.7 mm vs control 41.5 +/- 2.1 mm, P = 0. 01). Flap survival length was significantly longer than dye distance (49.1 +/- 2.0 mm vs 39.7 +/- 1.1 mm, P = 0.01). In the control flap, no significant difference between survival length and dye distance was detected. Histological examination 48 h after flap elevation showed leukocyte invasion in the dermal layer of control flaps, whereas little leukocyte invasion was observed in the flaps of rats administered sulfatide.  相似文献   
35.
Steroid 21-hydroxylase deficiency (21-OHD) accounts for 90–95% of congenital adrenal hyperplasia (CAH) cases. It is classified into three distinct clinical phenotypes: the salt-wasting (SW), simple virilizing (SV) and nonclassical forms (NC). As girls with the SW and SV forms of 21-OHD are exposed to high systemic levels of adrenal androgens during fetal life, they show genital ambiguity. To ameliorate the degree of genital virilization, prenatal dexamethasone treatment has been performed for more than two decades, although mainly in the USA and Europe. This treatment has proven to be effective in preventing or reducing genital virilization. Some data also show that prenatal diagnosis and treatment are safe for the mother and fetus. However, prenatal treatment is still controversial for the following reasons. First, the risk of having an affected female fetus is only one in eight when both parents are known carriers of the autosomal recessive trait. Therefore, seven of eight fetuses will receive dexamethasone unnecessarily, and this raises ethical questions. Furthermore, maternal side effects such as excessive weight gain and hypertension have been observed. Finally, the long-term safety and outcome for dexamethasone-exposed children have not been established. In Japan, prenatal diagnosis and treatment has rarely been reported because of these reasons. Therefore, we must be cautious, and this treatment should be carried out in special centers with the approval of their ethical committees, that are capable of performing chorionic villus sampling (CVS) and subsequently determining the karyotype and genotype of 21-OHD.  相似文献   
36.
37.
Objective: Treatment options for patients with rheumatoid arthritis on maintenance hemodialysis with an inadequate response to biologic agents have not been reported. In this report, we describe two patients who achieved remission after treatment with peficitinib.Methods: Two 69- and 85-year-old patients with rheumatoid arthritis on maintenance hemodialysis were previously treated with biologics and started on peficitinib 100 mg/day after the secondary failure of biologics.Discussion: In the two cases presented here, rheumatoid arthritis was almost in remission and there were no adverse events, although the patients were switched to peficitinib after secondary failure of the biologic agents. Among Janus kinase inhibitors, peficitinib has the lowest renal excretion; therefore, its administration in patients on dialysis is not contraindicated according to the package insert in Japan. The use of biologic agents in patients on hemodialysis has been reported to be associated with a high incidence of infections; therefore, care should be taken to avoid infections when administering Janus kinase inhibitors.Conclusion: Janus kinase inhibitors with low renal excretion, such as peficitinib, may be effective in patients with rheumatoid arthritis on maintenance hemodialysis who have an inadequate response to biologic agents.  相似文献   
38.
BackgroundFrom 2004 to 2014, 821 colorectal cancer primary resections were conducted at our institution. Of these, 102 patients (12.4%) were older adults over 80 years old. underwent either the conventional laparotomy group (72 patients) or the hand-assisted laparoscopic surgery (HALS) group (30 patients).MethodsData were extracted for 102 patients over 80 years old who underwent primary resection for colorectal cancer and were divided into two groups: conventional laparotomy (CL) (n=72) and hand-assisted laparoscopy (n=30). Pre-operative characteristics and outcomes were compared.ResultsBaseline characteristics were similar between groups, except for age: CL group median 83.5 years old (range, 80–92 years old) and hand-assisted laparoscopy (HALS) group median 81.5 years old (range, 80–88 years old) (P=0.027). Pre-operative cardiac and lung function risk, performance status, and pathological classification stage (pStage) were almost similar between groups (P=0.668, P=0.176, P>0.999, P=0.217). No significant differences were found for operation time. The HALS group resulted in less blood loss (median 204 mL in the CL group and median 68 mL in the HALS group, P=0.003), shorter postoperative hospital stay (median was 18 days in the CL group and median was 12 days in the HALS group, P<0.001), and fewer postoperative wound infections (18 cases in the CL group and 2 cases in the HALS group, P=0.034). Five-year relapse-free survival (5Y-RFS) was 48.1% in the CL group and 73.3% in the HALS group (P=0.028). Five-year overall survival (5Y-OS) was 48.2% in the CL group and 73.3% in the HALS group (P=0.027).ConclusionsApproximately 70% of surgical treatment for patients over 80 years old with colorectal carcinoma were performed by CL. However, HALS had significant advantages including less blood loss, fewer wound infections, and shorter hospital stays. Therefore, HALS could proactively be considered to older adult patients with colorectal cancer.  相似文献   
39.
40.
PURPOSE: To report successful pregnancies after the transfer of re-vitrified human day 7 blastocysts developed from vitrified cleaved embryos. METHODS AND RESULTS: A total of five day 7 blastocysts developed from vitrified cleaved embryos were re-vitrified and re-warmed. All of five re-vitrified day 7 blastocysts (100%) survived after warming and were transferred to three patients. Two of the women became clinically pregnant. Of these women, one woman delivered a healthy baby and the other pregnancy is ongoing at 26 weeks of gestation. CONCLUSIONS: This is the first report of successful pregnancies after the transfer of re-vitrified human day 7 blastocysts developed from vitrified cleaved embryos.  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