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   500篇
  免费   20篇
  国内免费   10篇
儿科学   1篇
妇产科学   46篇
基础医学   69篇
口腔科学   18篇
临床医学   34篇
内科学   58篇
皮肤病学   2篇
神经病学   103篇
特种医学   5篇
外科学   42篇
预防医学   14篇
药学   34篇
肿瘤学   104篇
  2023年   1篇
  2022年   6篇
  2021年   12篇
  2020年   4篇
  2019年   11篇
  2018年   16篇
  2017年   19篇
  2016年   13篇
  2015年   16篇
  2014年   21篇
  2013年   18篇
  2012年   45篇
  2011年   42篇
  2010年   29篇
  2009年   19篇
  2008年   31篇
  2007年   34篇
  2006年   23篇
  2005年   32篇
  2004年   21篇
  2003年   15篇
  2002年   10篇
  2001年   10篇
  2000年   17篇
  1999年   14篇
  1998年   5篇
  1997年   3篇
  1996年   6篇
  1995年   3篇
  1993年   3篇
  1992年   4篇
  1991年   8篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1958年   1篇
  1957年   1篇
排序方式: 共有530条查询结果,搜索用时 15 毫秒
51.
Ceramide is a sphingolipid with potent proinflammatory and proapoptotic properties. This study sought to determine whether pharmacological inhibition of ceramide biosynthesis in the intestine attenuates pathophysiological sequelae of shock induced by splanchnic artery occlusion and reperfusion. Ischemia and reperfusion injury was induced in anesthetized rats by clamping both the superior mesenteric artery and the celiac artery for 45 min followed by reperfusion. Within 6 min after reperfusion, animals developed significant systemic hypotension with 100% of the animals dying during the 4-h period of reperfusion. In parallel experiments, animals were necropsied after 60 min of reperfusion, and the ileum was harvested for histological examination and assessment of biochemical changes. Administration of fumonisin B1 (FB1), a competitive and reversible inhibitor of ceramide synthase (3 mg/kg, 15 min before reperfusion), significantly reduced i) the increased ceramide expression as detected by immunohistochemistry; ii) peroxynitrite-mediated protein nitration; iii) infiltration of the reperfused intestine with polymorphonuclear neutrophils following a decrease in intercellular adhesion molecule-1 expression; iv) production of the proinflammatory cytokine tumor necrosis factor-alpha; and v) apoptosis in the ileum. Overall, tissue-protective effects were clearly observed upon histological examination of the ileum. These beneficial events were ultimately linked to decreases in both the development of hypotension and overall mortality. These results implicate ceramide as a key signaling molecule in splanchnic arterial ischemia and reperfusion-induced shock. The broader implications of our results provide a pharmacological rationale for the development of inhibitors of ceramide biosynthesis as novel therapeutics for ischemia and reperfusion-induced shock of several etiologies.  相似文献   
52.
53.
The advent of highly active antiretroviral therapy (HAART) has lead to a substantial reduction in the prevalence, morbidity, and mortality associated with AIDS-related Kaposi's sarcoma. Similarly, concomitant advances in chemotherapy and supportive-care protocols have allowed for Kaposi's sarcoma to be managed more effectively in comparison with the pre-HAART era. Furthermore, developments in our understanding of the pathogenesis of Kaposi's sarcoma have identified several molecular targets that can potentially provide new therapeutic strategies. This Review discusses the role of conventional chemotherapeutic and immunomodulatory agents in the treatment of Kaposi's sarcoma and summarises the current status and future prospects of novel molecularly targeted agents in the treatment of this disease.  相似文献   
54.
AIM: This is a phase I study investigating the toxicity and the potential efficacy of thalidomide and oral cyclophosphamide in patients with hormone refractory prostate cancer (HRPC), previously treated with docetaxel-based regimens. METHODS: Two dose levels of thalidomide (100 and 200 mg every day) were studied. Patients were accrued to each dose level in cohorts of 3 starting from dose 1 level (100 mg). Thalidomide was started on day 1 at the assigned dose and continued for four consecutive weeks; oral cyclophosphamide (50 mg for day) was given for four consecutive weeks (1 cycle) starting on the same day initiating thalidomide. Toxicity was evaluated every two weeks; changes in prostate-specific antigen (PSA) levels were evaluated every cycle. Treatment was planned for four cycles. RESULTS: Sixteen men were treated. Ten patients in cohort 1, and 6 in cohort 2 were enrolled respectively. Grade 1-2 constipation, peripheral neuropathy and fatigue were the most common side effects, noted in 6 (37.5%), 5 (31.25%) and 3 (19%) patients, respectively. Three patients stopped the treatment at level 2, during the first cycle, for toxicity. Those three patients were evaluable only for toxicity. The MTD was 100 mg thalidomide. Thirteen patients completed two cycles. Two patients (15%) had a >50% decrease in PSA, while in one patient (8%) the PSA decrease was less of 50%. Overall PSA decrease was of 23%. CONCLUSIONS: The oral combination of thalidomide and cyclophosphamide is well tolerated and appears to be associated with biochemical response in this population. Future phase II trials, in pre-treated and untreated patients, are needed to evaluate clinical efficacy of this regimen in HRPC.  相似文献   
55.
A novel neural network-based survival analysis model.   总被引:1,自引:0,他引:1  
A feedforward neural network architecture aimed at survival probability estimation is presented which generalizes the standard, usually linear, models described in literature. The network builds an approximation to the survival probability of a system at a given time, conditional on the system features. The resulting model is described in a hierarchical Bayesian framework. Experiments with synthetic and real world data compare the performance of this model with the commonly used standard ones.  相似文献   
56.
57.
58.
The Authors report their experience with the use of GnRH analogue (Goserelin) in 35 women with abnormal uterine bleeding due to low-risk hyperplasia of the endometrium. A hysteroscopic and histopathological follow-up was performed at 2 months and 6 months after treatment. The results show a significantly effectiveness of Goserelin in treating dysfunctional uterine bleeding.  相似文献   
59.
BACKGROUNDSarcopenia is a condition characterized by decreased skeletal muscle mass due to physiological ageing or to a concomitant disease such as neoplasia. In cancer patients, a low lean body mass is suggested to be a negative prognostic factor for survival and for the development of dose-limiting chemotherapy toxicities irrespective of disease stage. AIMTo evaluate the prognostic role of sarcopenia in patients with metastatic colorectal cancer (mCRC) undergoing first-line chemotherapy.METHODSOur retrospective analysis included 56 mCRC patients who received first-line chemotherapy from 2014 to 2017 at the Medical Oncology Unit of our hospital. Computerized scans were performed before starting chemotherapy and at the first disease reassessment. Sarcopenia was assessed using the skeletal mass index = muscle area in cm2/(height in m2) calculated at the L3 vertebra. Overall survival and objective response rate were evaluated. Toxicities were analyzed during the first four cycles of therapy and graded according to Common Terminology Criteria for Adverse Events version 4.0. A loss of skeletal muscle mass ≥ 5% was considered indicative of deterioration in muscle condition.RESULTSMedian age was 67 years and 35.7% of patients were ≥ 70 years old. Fourteen patients (25%) were sarcopenic at baseline computed tomography (CT) scan (7/33 men; 7/23 women); 5/14 sarcopenic patients were ≥ 70 years old. Median follow-up was 26.8 mo (3.8-66.8 mo) and median overall survival was 27.2 mo (95%CI: 23.3-37.3). Sarcopenia was not correlated to overall survival (P = 0.362), to higher toxicities reported during the first 4 cycles of chemotherapy (P = 1.0) or to response to treatment (P = 0.221). At the first disease reassessment, a skeletal muscle loss (SML) ≥ 5% was found in 17 patients (30.3%) 3 of whom were already sarcopenic at baseline CT scan, while 7 patients became sarcopenic. SML was not correlated to overall survival (P = 0.961). No statistically significant correlation was found between baseline sarcopenia and age (P = 1.0), body mass index (P = 0.728), stage at diagnosis (P = 0.355) or neutrophil/lymphocyte ratio (P = 0.751).CONCLUSIONNeither baseline sarcopenia nor SML affected survival. In addition, baseline sarcopenia was not related to worse treatment toxicity. However, these results must be interpreted with caution due to the limited sample size.  相似文献   
60.
Amyotrophic lateral sclerosis (ALS) is a disabling progressive disease characterized by the degeneration of motor neurons, leading to muscle atrophy and paralysis. The majority of cases are sporadic, but also a familiar form of ALS exists, and some genes causative of the pathology were found. In particular, mutations in superoxide dismutase 1 (SOD1) were found in 20% of familiar cases. It is known that neuroinflammation plays a pivotal role in several neurodegenerative disorders, including ALS. Inflammasomes are protein complexes that induce inflammation in response to various stimuli, involved also in neuroinflammation. The NLRP3 inflammasome, which is the best known, after assembly, induces the activation of caspase 1, which in turn activates interleukin (IL)-1β and IL-18. The aim of this work was the evaluation of inflammasome activation in the brain of SOD1G93A rats, a transgenic model of ALS. We observed the increase in TLR4 and nuclear NF-κB levels in SOD1G93A rats. Their activation is known as priming signal for inflammasome induction. Moreover, NLRP3 protein increased, associated with the presence of active caspase 1, leading to an increase in IL-18 and IL-1β levels. In addition, IL-1β, IL-18, and IFN-γ amount increased in the spleen of SOD1G93A rats, together with an increased expression of CD4, CD8, CD44, and CD68 markers. In conclusion, our results showed the activation of the NLRP3 inflammasome in the brain of SOD1G93A rats, indicating that inflammation plays a main role in ALS.  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