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   2687篇
  免费   105篇
  国内免费   22篇
耳鼻咽喉   112篇
儿科学   163篇
妇产科学   91篇
基础医学   172篇
口腔科学   71篇
临床医学   182篇
内科学   557篇
皮肤病学   30篇
神经病学   256篇
特种医学   114篇
外科学   722篇
综合类   34篇
预防医学   34篇
眼科学   72篇
药学   90篇
中国医学   1篇
肿瘤学   113篇
  2024年   2篇
  2023年   16篇
  2022年   13篇
  2021年   52篇
  2020年   38篇
  2019年   56篇
  2018年   57篇
  2017年   35篇
  2016年   90篇
  2015年   96篇
  2014年   105篇
  2013年   138篇
  2012年   176篇
  2011年   150篇
  2010年   106篇
  2009年   93篇
  2008年   202篇
  2007年   233篇
  2006年   211篇
  2005年   226篇
  2004年   196篇
  2003年   175篇
  2002年   139篇
  2001年   40篇
  2000年   31篇
  1999年   24篇
  1998年   23篇
  1997年   10篇
  1996年   11篇
  1995年   8篇
  1994年   6篇
  1993年   5篇
  1992年   4篇
  1991年   12篇
  1990年   12篇
  1989年   7篇
  1988年   5篇
  1984年   4篇
  1983年   1篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1966年   1篇
排序方式: 共有2814条查询结果,搜索用时 15 毫秒
1.
Introduction: Dysregulation of histone deacetylase (HDAC) activity is an epigenetic hallmark of multiple myeloma (MM), leading to aberrant gene expression and cellular signaling in myeloma cell growth, survival and resistance to therapy. Hyper-methylation at diagnosis is a frequent observation, which eventually may convert to hypo-methylation during advanced phases.

Areas covered: A literature search on ‘HDAC inhibitors’ and ‘multiple myeloma’ was carried out using PubMed and Google Scholar in the preparation of this overview on clinical efficacy and safety data.

Expert opinion: First-generation non-selective HDAC inhibitors have demonstrated minimal single-agent activity in refractory MM. Subsequently, combination therapy has proven an improvement in progression-free survival (PFS) but not response rates. The main concerns are associated with toxicities. Ongoing studies on new and more selective agents, i.e. Romidepsin or Ricolinostat, are promising in terms of better efficacy and less toxicity.  相似文献   

2.
3.
Abstract –  In the treatment of crown fractures, adhesive fragment reattachment provides a good alternative to other restorative techniques, offering several advantages. The present paper reports a case in which the treatment of a cervical crown fracture was accomplished by reattaching the tooth fragment with a flowable resin composite. Orthodontic root extrusion was performed with a modified Hawley appliance prior to fragment reattachment. The clinical and radiographic results after 2.5 years were successful.  相似文献   
4.
Midazolam is a recently developed water-soluble benzodiazepine that shares anxiolytic, muscle relaxant, hypnotic and anticonvulsant actions with other members of this class. There are limited studies that midazolam can be used successfully to treat seizures in adults and children. In this study, 0.2 mg/kg intramuscular (IM) midazolam was administered to 11 children (eight boys and three girls), aged 3 days to 4 years (mean age 1.8±1.4 years), with seizures of various types. In all but one child, seizures stopped in 15 s–5 min after injection. No side effects were observed. These results suggest that IM administration of midazolam may be useful in a variety of seizures during childhood, especially in case of intravenous (IV) line problem.  相似文献   
5.
Vascular lesions in Beh?et's disease are generally localized in the venous system: up to 24% of the cases reported in the literature are accompanied by thrombosis/thrombophlebitis. Reports of arterial involvement are rare but have increased during the last decade. Surgical treatments of arterial aneurysms and occlusions are often followed by recurrences due to progression or relapses of the inflammatory vessel wall lesions. Aneurysms of the pulmonary artery are rare. They may be complicated by thrombosis within the aneurysm and massive hemoptysis due to bronchial erosion and formation of an arterio-bronchial fistula. 27 cases of Beh?et's disease are reported.  相似文献   
6.
OBJECTIVE: The aim of this study was to assess the efficacy of inhaled morphine for preemptive analgesia in patients who undergo septoplasty or septorhinoplasty. STUDY PLAN AND METHODS: Eighty ASA I-II patients scheduled for septoplasty or septorhinoplasty were recruited and randomly divided into 2 groups that received different treatments 10 minutes prior to induction. The preemptive analgesia group (Group P, n = 40) received 65 mug kg(-1) morphine sulphate (a 3-mL volume) via an oral nebulizer, and the control group (Group C, n = 40) received 3 mL 0.9% sodium chloride (physiological saline) via the same type of nebulizer. Blood pressure, oxygen saturation, heart rate, time to first requirement for analgesia, and occurrence of nausea/vomiting were recorded. RESULTS: There were no significant differences between Groups P and C with respect to age, body weight, sex distribution, or duration of surgery. There was also no significant difference between the group frequencies of postoperative nausea/vomiting. The time to first requirement for analgesia was significantly longer in Group P than Group C. CONCLUSION: The results of this preliminary study suggest that a single dose of inhaled morphine administered preemptively prior to septoplasty or septorhinoplasty provides effective postoperative analgesia. EBM rating: B-3b.  相似文献   
7.
Chlamydial infections and male infertility   总被引:3,自引:0,他引:3  
Chlamydial infections may be difficult to diagnose due to the silent symptoms and difficulty in culturing. An infectious process may impair fertility by adversely affecting sperm functions, resulting in testicular damage or causing obstruction of the genital tract. In our study, we tried to find Chlamydial antigen by using EIA (Enzyme Immune Assay) and to compare the Ag(+) and Ag(−) groups according to semen parameters. Except for semen volume, we found significant differences in density, morphology, motility and viability (intervolume p>0.05, interdensity p<0.01, intermorphology p<0.001, intermotility p<0.001 and interviability p<0.001).  相似文献   
8.
Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5 ± 2.7 and 31.6 ± 2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamilton Depression Scale (mean: 23.2 ± 1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex.  相似文献   
9.
In obstructive jaundice, free radical production is increased and antioxidative activity is reduced. N-Acetylcysteine (NAC) has a beneficial effect with anti-inflammatory and antioxidant activity, acting as a free radical scavenger. NAC inhibits inducible nitric oxide synthase, suppresses cytokine expression/release, and inhibits adhesion molecule expression and nuclear factor kappa B. The aim of this study was to investigate the effects of NAC on liver/renal tissue and serum lipid peroxidation in lipopolysaccharide (LPS)-induced obstructive jaundice. We randomized 60 rats into 6 groups: group 1, Sham; group 2, obstructive jaundice (OJ) induced after bile-duct ligation; group 3, OJ + NAC (100 mg kg- 1 subcutaneously); group 4, OJ + LPS (10 mg kg-1); group 5, OJ + NAC + LPS; and group 6, OJ + LPS + NAC. For each group, the biochemical markers of lipid peroxidation and the antioxidant products were measured in serum and liver/renal tissue after sacrifice. Almost all lipid peroxidation products levels were increased and antioxidant products levels were decreased in groups who received LPS (groups 4, 5, and 6), but the effect was less remarkable when NAC was administered before LPS (group 5). The same trend was seen for groups with OJ +/- LPS who did not received NAC or received it after induced toxemia (groups 2, 4, and 6) as compared to groups 1 and 3. Moreover, in the case of OJ + LPS, rats treated with NAC before LPS (group 5) had lower lipid peroxidation products levels and higher antioxidant products levels as compared to those who did not received NAC (group 4). This phenomenon was not reproducible with NAC administered after LPS (group 6). Thus, results of this study showed that NAC prevents the deleterious effects of LPS in obstructive jaundice by reducing lipid peroxidation in serum and liver/renal tissue if administered before LPS. Nonetheless, NAC failed to prevent the lipid peroxidation in the case of established endotoxemia in obstructive jaundice.  相似文献   
10.
OBJECTIVE: The purpose of this study was to evaluate whether intracoronary shunt usage reduced the myocardial damage on the basis of the cardiac markers when compared with the shuntless anastomosis in off-pump coronary artery bypass grafting (OPCABG) surgery of isolated left anterior descending artery lesions. METHODS: Forty patients who had stable angina with isolated left anterior descending (LAD) coronary artery lesion undergoing OPCABG surgery were randomized into two groups. Shunt group consisted of 20 patients who had OPCABG using intracoronary shunt, whereas the shuntless group consisted of 20 patients who underwent OPCABG without using intracoronary shunt. Cardiac troponin I, CK, and CK-MB before and 24h after the surgery were assessed in the groups. RESULTS: There were no deaths in the study. The two groups were similar with respect to sex and age. Duration of LIMA-LAD anastomosis was significantly higher in the shunt group (p=0.01). There was no significant difference between the groups concerning the preoperative and postoperative CK and CK-MB levels. The preoperative troponin I levels of the groups were not different (p=0.238; NS), whereas postoperative levels of this marker was significantly higher in the shuntless group (p=0.003). CONCLUSION: Intracoronary shunt reduced the postoperative troponin I levels significantly, so it may be indicated in the patients who are thought to be susceptible to transient ischemia.  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