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   2458篇
  免费   98篇
  国内免费   16篇
耳鼻咽喉   9篇
儿科学   24篇
妇产科学   22篇
基础医学   292篇
口腔科学   62篇
临床医学   209篇
内科学   639篇
皮肤病学   66篇
神经病学   176篇
特种医学   31篇
外科学   522篇
综合类   9篇
预防医学   92篇
眼科学   17篇
药学   156篇
肿瘤学   246篇
  2022年   20篇
  2021年   29篇
  2020年   23篇
  2019年   35篇
  2018年   25篇
  2017年   22篇
  2016年   37篇
  2015年   32篇
  2014年   34篇
  2013年   53篇
  2012年   87篇
  2011年   106篇
  2010年   49篇
  2009年   52篇
  2008年   85篇
  2007年   90篇
  2006年   80篇
  2005年   101篇
  2004年   92篇
  2003年   84篇
  2002年   90篇
  2001年   98篇
  2000年   101篇
  1999年   92篇
  1998年   42篇
  1997年   15篇
  1996年   24篇
  1995年   33篇
  1994年   20篇
  1993年   21篇
  1992年   87篇
  1991年   57篇
  1990年   80篇
  1989年   77篇
  1988年   78篇
  1987年   72篇
  1986年   75篇
  1985年   52篇
  1984年   44篇
  1983年   28篇
  1980年   13篇
  1979年   29篇
  1978年   19篇
  1976年   13篇
  1975年   13篇
  1974年   15篇
  1970年   15篇
  1968年   16篇
  1967年   16篇
  1965年   12篇
排序方式: 共有2572条查询结果,搜索用时 31 毫秒
61.
Previous studies have found markedly elevated serum concentrations of proinflammatory cytokines in patients with Graves’ disease (GD). We investigated the role of macrophage colony-stimulating factor (M-CSF) in GD. We assayed concentrations of M-CSF in sera from 32 patients with GD (25 untreated; 7 receiving thiamazole therapy). We also studied 32 age-matched healthy subjects as controls. Relationships between serum M-CSF and both thyroid state and serum lipids were examined. Moreover, to examine the effect of thyroid hormone alone on serum M-CSF, T3 was administered orally to normal subjects. Serum concentrations of M-CSF in GD patients who were hyperthyroid were significantly increased compared with GD patients who were euthyroid (P < 0.05) and control subjects (P < 0.0001). Serum M-CSF concentrations correlated closely with T3 levels in patients (= 0.51, < 0.005). Serial measurement of five individual patients revealed that serum concentrations of M-CSF were significantly decreased (P < 0.05), reaching normal control values upon attainment of euthyroidism. Furthermore, oral T3 administered to 15 volunteers for 7 days produced significant increases in serum levels of M-CSF (< 0.05). The close correlation between serum M-CSF and serum thyroid hormone levels suggests that high circulating levels of thyroid hormones may directly or indirectly potentiate the production of M-CSF in patients with GD.  相似文献   
62.
OBJECTIVE: In the early phase after transmural myocardial infarction (MI), the infarcted myocardium undergoes replacement by scar tissue, which is essential for preserving the structural integrity of the infarcted tissue. Transforming growth factor (TGF)-beta1, which is known as a fibrotic cytokine, plays a pivotal role in the reparative fibrosis after MI. It is reported that granulocyte colony-stimulating factor (G-CSF) can accelerate wound healing. The aim of our study was to investigate the effect of G-CSF on early ventricular expansion after MI. METHODS: MI was induced by ligation of the left coronary artery in male Wistar rats. G-CSF (20 microg/kg/day, MI-GCSF) or saline (MI-saline) was injected subcutaneously 3 h after MI and every 24 h thereafter for 7 days. Hemodynamic and echocardiographic studies were performed at 14 days. Expression of TGF-beta1 and procollagen type I and type III mRNA in both the infarcted and noninfarcted areas was studied by quantitative RT-PCR at 1, 3, 7, and 14 days after MI. Histological studies were performed at 7 days. RESULTS: MI-GCSF had higher LV max dP/dt, lower LV end-diastolic pressure, and smaller LV end-diastolic and end-systolic dimensions compared to MI-saline. Infarct size was not different between MI-GCSF and MI-saline. Expression of TGF-beta1 mRNA in the infarcted area at 3 days was significantly higher in MI-GCSF than in MI-saline. Expression of procollagen type I and type III mRNA in the infarcted area at 3 days was higher in MI-GCSF compared to MI-saline, and the peak mRNA levels were earlier in MI-GCSF. In the noninfarcted area, there was no difference in TGF-beta1 mRNA expression between MI-GCSF and MI-saline. Histologically, collagen accumulation in the infarcted area at 7 days was more prominent in MI-GCSF than in MI-saline. CONCLUSION: G-CSF treatment improves early post-infarct ventricular expansion through promotion of reparative collagen synthesis in the infarcted area, suggesting some beneficial effect of G-CSF on the infarct healing process.  相似文献   
63.

Background

The association between isolated admission heart rate (HR) and prognosis has been discussed, but not that between gross HR change and neurological outcome in patients with severe traumatic brain injury (TBI). In the acute phase of severe TBI, HR is influenced by several factors (e.g., pain, sympathetic activation, hypovolemia, fever, body temperature). Therefore, admission HR and gross HR change should be examined in patients with TBI treated with a well-designed protocol, such as was done in the Brain Hypothermia (B-HYPO) Study.

Methods

This was a post hoc analysis of the B-HYPO Study, which was conducted as a prospective, multicenter, randomized controlled trial in patients with severe TBI receiving mild therapeutic hypothermia (MTH; 32.0?°C–34.0?°C) or fever control (35.5?°C–37.0?°C) in Japan. Patients with MTH were examined, and HR change (%HR) in the early MTH phase was calculated as follows: [admission HR – HR at day 1]/admission HR?×?100. Patients were divided into six groups, using admission HR (<?80, 80–99, ≤?100) and median of %HR; i.e., group (Admission HR <?80 and %HR ≥?18.6); group (Admission HR <?80 and %HR <?18.6); group (Admission HR 80–99 and %HR ≥?18.6); group (Admission HR 80–99 and %HR <?18.6); group (Admission HR ≥100 and %HR ≥?18.6); and group (Admission HR ≥100 and %HR <?18.6). The primary outcome was an adjusted predicted probability of unfavorable neurological outcome at 6 months after TBI according to Glasgow Outcome Scale score, which is a measure of functional recovery and defined as severe disability, persistent vegetative state, and death.

Results

Overall, 79 patients with MTH (52.7% of the original trial) were examined; among these, unfavorable neurological outcomes were observed in 53.2%. Among all the groups, group (Admission HR ≥100 and %HR <?18.6) exhibited the highest proportion of unfavorable outcomes, and 82.3% of patients had an adjusted predicted probability of unfavorable outcomes, whereas those in group (Admission HR <?80 and %HR ≥?18.6) developed only 22.8% (p?=?0.04).

Conclusions

Mild HR decrease during the early phase of targeted temperature management following tachycardia at admission can be associated with unfavorable neurological outcomes after severe TBI.
  相似文献   
64.
Since a variety of cell intrinsic and extrinsic molecular abnormalities cooperatively promote tumor formation in multiple myeloma (MM), therapeutic approaches that concomitantly target more than one molecule are increasingly attractive. We herein demonstrate the anti-myeloma effect of a cephalotaxus alkaloid, homoharringtonine (HHT), an inhibitor of protein synthesis, through the induction of apoptosis. HHT significantly reduced Mcl-1, a crucial protein involved in myeloma cell survival, in all three myeloma cell lines examined, whereas certain BH3-only proteins, such as Bim, Bik, and Puma, remained unchanged following HHT treatment, and their expression levels depended on the cell type. HHT also reduced the levels of c-FLIP(L/S), activated caspase-8, and induced active truncated-Bid. Thus, HHT-induced apoptosis appears to be mediated via both intrinsic and extrinsic apoptosis pathways, and the resultant imbalance between BH3-only proteins and Mcl-1 may be pivotal for apoptosis by HHT. In addition, HHT treatment resulted in reduced levels of beta-catenin and XIAP proteins, which also contribute to disease progression and resistance to chemotherapy in MM. In combination, HHT enhanced the effects of melphalan, bortezomib, and ABT-737. These results suggest that HHT could constitute an attractive option for MM treatment though its ability to simultaneously target multiple tumor-promoting molecules.  相似文献   
65.
66.
67.
68.
The treatment of patients with aggressive subclasses of myelodysplastic syndrome (MDS) remains a challenge. In an effort to improve the survival of patients with refractory anemia with excess blasts (RAEB), RAEB in transformation (RAEB-t), or acute myelogenous leukemia transformed from MDS (MDS-AML), we conducted a small trial in which 28 such patients were treated with low-dose cytosine arabinoside (LDAraC) followed by administration of macrophage colony-stimulating factor (M-CSF). The overall rate of response to the treatment was 61%, including 39% with a complete response, which is higher than rates obtained in previous studies in which LDAraC alone was administered to patients with MDS. Median survival was 23.5 months in cases of RAEB, 16.7 months in cases of RAEB-t, and 19.7 months in cases of MDS-AML. The overall survival of the study group appeared to be prolonged in comparison with a historical control group of patients treated with LDAraC alone. It is suggested that M-CSF added to the administration of LDAraC plays an active role in the therapy. No therapy-related death occurred. Some unique actions of M-CSF were suggested in this trial. It is concluded that therapy with LDAraC + M-CSF is a useful treatment option for patients with aggressive subclasses of MDS and MDS-AML to provide better response and survival.  相似文献   
69.
We conducted a randomized crossover study comparing the hemopoietic effect of partially purified human urinary colony-stimulating factor (CSF-HU, an active drug) and human serum albumin (HSA, a control drug) in 24 patients with malignant lymphoma, solid tumors, or multiple myeloma who were receiving two consecutive courses of the same chemotherapeutic regimen. Patients received daily 2-4 X 10(6) units of CSF-HU or an equal amount of protein HSA for five days after the end of the courses of chemotherapy. Assignment to CSF-HU or HSA was determined by the envelope method. The average number of blood granulocytes of 24 cases on day 7 after chemotherapy was 2116 +/- 1649 in CSF-HU-infused courses, which was significantly higher than in HSA-infused courses (1520 +/- 1022) (p less than 0.05). The average time that patients had fewer than 2000 granulocytes/mm3 was 7.6 +/- 4.4 days in CSF-HU-infused courses and 10.3 +/- 5.0 days in HSA-infused courses (p less than 0.02). Fever greater than 38 degrees C was the most frequent side effect, occurring in 32% of the patients receiving CSF-HU infusions. A reduction in the neutropenic interval in CSF-HU-infused courses was observed in patients with fever, as well as in those without fever. Infusions of CSF-HU did not change the number of other hematological parameters, such as erythrocytes, platelets, monocytes, and lymphocytes. These results suggest that CSF-HU infusions may partially protect the patients from granulocytopenia after anticancer chemotherapy.  相似文献   
70.
Siba, a new platelet-specific alloantigen involved in a case of platelet transfusion refractoriness is reported. The IgG platelet alloantibody was detected in a multiply transfused patient of Japanese extraction (Sib), by the presence of HLA antibodies. After transfusion of HLA-compatible platelets, the patient suffered from refractoriness. Adsorption studies with pooled lymphocytes showed that the serum contained anti-platelet activity. Family studies indicate that Siba is inherited as an autosomal codominant trait and separate from HLA and Baka. As of this report, segregation from Zw(PlA) and Yuk (Pen) antigen systems have not yet been determined. The gene frequency of Siba in the Japanese population is estimated to be 0.136.  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