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   632篇
  免费   52篇
  国内免费   68篇
耳鼻咽喉   1篇
儿科学   6篇
妇产科学   14篇
基础医学   44篇
口腔科学   1篇
临床医学   93篇
内科学   101篇
皮肤病学   1篇
神经病学   8篇
特种医学   72篇
外科学   288篇
综合类   14篇
预防医学   11篇
眼科学   1篇
药学   54篇
肿瘤学   43篇
  2021年   3篇
  2020年   3篇
  2019年   5篇
  2014年   4篇
  2013年   13篇
  2012年   3篇
  2011年   12篇
  2010年   13篇
  2009年   15篇
  2008年   16篇
  2007年   55篇
  2006年   15篇
  2005年   25篇
  2004年   7篇
  2003年   20篇
  2002年   24篇
  2001年   14篇
  2000年   26篇
  1999年   25篇
  1998年   23篇
  1997年   19篇
  1996年   23篇
  1995年   18篇
  1994年   8篇
  1993年   14篇
  1992年   17篇
  1991年   27篇
  1990年   20篇
  1989年   28篇
  1988年   21篇
  1987年   32篇
  1986年   18篇
  1985年   18篇
  1984年   20篇
  1983年   8篇
  1982年   6篇
  1980年   7篇
  1979年   12篇
  1978年   17篇
  1977年   13篇
  1976年   6篇
  1975年   9篇
  1974年   9篇
  1973年   7篇
  1972年   4篇
  1971年   8篇
  1934年   4篇
  1930年   4篇
  1928年   4篇
  1927年   8篇
排序方式: 共有752条查询结果,搜索用时 15 毫秒
1.
2.
Carcinoid syndrome occurs in about five percent of patients with carcinoid tumours. Most of these patients have diffuse liver metastases at the first presentation and the surgical options are few. Medical treatment or hepatic dearterialization achieves a temporary response in most cases. Occasionally, the liver lesions are confined to one anatomical lobe and resection may be feasible.  相似文献   
3.
Repeat hepatic resections for metastatic colorectal cancer.   总被引:7,自引:0,他引:7       下载免费PDF全文
OBJECTIVE: The authors weighed the risks and benefits of repeat liver resections for colorectal metastatic disease. METHOD: In the 6-year period between January 1985 and June 1991, 499 patients underwent liver resections for colorectal metastases at the Memorial Sloan-Kettering Cancer Center. Of these, 25 patients had repeat surgical resections for isolated recurrent disease to the liver. The clinical data for these patients were reviewed. RESULTS: The median interval between the two resections was 11 months. There were no perioperative deaths, and the complication rate was 28%. Median follow-up after the second liver resection is 19 months, with median survival of 17 months for nonsurvivors. Although the median survival after the second resection is 30 months, 20 of the 25 patients have had recurrences with a median disease-free interval of only 9 months. No characteristic of primary or metastatic disease predicted outcome, including time between presentation of the primary and development of liver metastases, disease-free interval after the first liver resection, and bilobar liver involvement. CONCLUSIONS: Although repeat liver resections can be performed safely and improves survival, the likelihood of cure from such resection therapy is low. This likelihood of further recurrences encourage studies of adjuvant or alternative treatments of this population.  相似文献   
4.
Background: Studies have consistently confirmed the benefit of liver resection for metastatic colorectal cancer. Few reports, however, have a long enough followup or sufficient 5-year survivors to study the clinical course of patients beyond 5 years.

Study Design: From July 1985 through December 1991, 456 patients underwent liver resection for colorectal metastases. Ninety-six actual 5-year survivors (21%) were identified and their clinical course retrospectively reviewed.

Results: Five-year survivors (n = 96) were more likely to have a Duke’s B primary colorectal carcinoma, fewer than four metastatic lesions, unilobar disease, and a negative histologic margin when compared with patients not surviving 5 years (n = 298). Forty-four (46%) of the 96 five-year survivors had a recurrence after hepatectomy. Of these 44, 19 (43%) were rendered disease free after further treatment. Overall, 71 of the 96 five-year survivors were free of disease at last followup. The actuarial 10-year survival of this group was 78%.

Conclusions: Patients that are disease free 5 years after liver resection are likely to have been cured by liver resection. Patients should be aggressively followed for recurrence because of the potential for further treatment and longterm survival.  相似文献   

5.
硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用   总被引:8,自引:1,他引:7  
研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。  相似文献   
6.
Giant hepatic hemangiomas: diagnostic and therapeutic dilemmas   总被引:3,自引:0,他引:3  
This report describes four cases of surgically treated giant hepatic hemangiomas which illustrate some diagnostic and therapeutic difficulties encountered in the management of this condition. An important diagnostic triad has emerged, which should alert the physician to the possibility of a complicated hepatic hemangioma: the clinical signs of an acute inflammatory liver process contrasted with a normal white blood cell count and liver function tests. Hemangiomas of the left lobe were either missed or poorly demonstrated on selective hepatic angiographic examination, and in two patients the diagnosis was made only at the time of laparotomy. Hepatic resection was successfully performed in all patients; there was minimal morbidity and none of the patients died. In two patients with multiple hemangiomas, only symptomatic or easily resectable lesions were removed. All patients are alive and well; three have been followed up for more than 5 years. We conclude that resection in asymptomatic cases should be carried out only in those cases that require a diagnostic laparotomy and in those where the lesion is easily resectable. The majority of patients with symptomatic and complicated tumors should undergo resection, but even in these patients continued conservative treatment is appropriate when the risk of major resection outweighs the small risk of live-threatening bleeding.  相似文献   
7.
8.
Introduction : Hypertrophic scar is a devastating sequel to burns and other tangential skin injuries. It follows deep dermal injuries and does not occur after superficial injuries. Nitric oxide (NO) plays many important roles in wound healing from inflammation to scar remodeling. Studies have shown that expression of nitric oxide synthase and nitric oxide production are decreased in human hypertrophic scar. However little is known about NO involvement in the early stages of hypertrophic scarring, because of the lack of an animal model. It was recently reported that the female red Duroc pig (FRDP) makes thick scar, which is similar to human hypertrophic scar. We hypothesized that NO production in wounds on the female, red Duroc pig is similar to that of human hypertrophic scar and that NO involvement in deep wounds is different from that in superficial wounds. Methods : Superficial (0.015” to 0.030”) and deep (0.045” to 0.060”) wounds were created on the backs of four FRDPs. Biopsies were collected at weeks 1.5, 4, 8 and 21 post wounding including samples of uninjured skin. Nitric oxide levels were measured with the Griess reaction assay and normalized with tissue protein level. Results : Superficial wounds healed with an invisible scar whereas the deep wounds healed with scar resembling mild hypertrophic scar. The thickness of the scars from the deep wounds was significantly greater than uninjured skin and healed superficial wounds (p < 0.01). NO levels were increased at 1.5 weeks in deep wounds compared to superficial wounds and uninjured skin (p < 0.05). At 8 weeks, NO levels in deep wounds had returned to the level of uninjured tissue and superficial wounds. By 21 weeks, NO levels had decreased significantly when compared to superficial wounds (p < 0.01). There were no differences in NO levels between uninjured skin and superficial wounds at any time point (p > 0.05). Conclusions : NO production is similar in late, deep wounds on the female, red Duroc pig to that reported in the literature for human hypertrophic scar further validating this animal model. NO production is quite different after deep wounds as compared to superficial wounds in the FRDP. Early elevation in nitric oxide production might account for excessive inflammation in deep wounds that become thick scars in the FRDP. Nitric oxide regulators and effects at early stages of scar formation should be elucidated further and the FRDP appears to be a useful model.  相似文献   
9.
Structural abnormalities are found in the astrocytes of the dentate nuclei of animals after portacaval shunting (PCS). These changes are also found in man in association with portal-systemic encephalopathy. To investigate the relationship between portal-systemic shunting and hepatocellular dysfunction in the pathogenesis of these changes, PCS and protacaval transposition (PCT) were performed in rats. PCT diverts portal blood into the systemic circulation, but retains normal total hepatic blood flow by perfusion with systemic venous blood. Liver function and mass are better preserved than after PCS. Abnormal glial cells were found in 4.03% of animals following sham operation, 13.45% following PCT, and 19.09% following PCS. Both experimental groups differed significantly from control animals, and the number of abnormal cells was significantly higher after PCS than after PCT. These findings are in keeping with the hypothesis that hepatocellular dysfunction plays an important role in addition to portal-systemic shunting in the aetiology of the structural changes in the brain associated with hepatic encephalopathy.  相似文献   
10.
乳腺管状小叶癌(Tubulolobular carcinoma,TLC)最初是被作为小叶癌的管状变型。作者总结了27例TLC的组织学、免疫表型和临床特征,并与纯小管癌和经典型小叶癌进行了比较。此组患者年龄43-79岁(中位年龄60岁)。1例双侧乳腺受累,5例病变为多灶性。肿瘤直径0.5-2.5cm,色灰褐,质硬。组织学观察:TLC的肿瘤细胞形成管状和条索状两种结构模式并相互混杂,且两者比例相当(统称为管状小叶模式)。  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