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   1129篇
  免费   82篇
  国内免费   12篇
耳鼻咽喉   15篇
儿科学   70篇
妇产科学   44篇
基础医学   94篇
口腔科学   88篇
临床医学   105篇
内科学   222篇
皮肤病学   18篇
神经病学   114篇
特种医学   55篇
外科学   190篇
综合类   17篇
预防医学   29篇
眼科学   46篇
药学   57篇
中国医学   5篇
肿瘤学   54篇
  2023年   17篇
  2022年   21篇
  2021年   43篇
  2020年   31篇
  2019年   38篇
  2018年   42篇
  2017年   41篇
  2016年   58篇
  2015年   52篇
  2014年   54篇
  2013年   93篇
  2012年   86篇
  2011年   80篇
  2010年   42篇
  2009年   56篇
  2008年   75篇
  2007年   93篇
  2006年   77篇
  2005年   70篇
  2004年   59篇
  2003年   46篇
  2002年   23篇
  2001年   9篇
  2000年   1篇
  1999年   2篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1985年   1篇
  1984年   1篇
  1979年   1篇
排序方式: 共有1223条查询结果,搜索用时 31 毫秒
1.
Graefe's Archive for Clinical and Experimental Ophthalmology - To evaluate central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and visual outcomes following different...  相似文献   
2.
3.
4.
Teeth with white spot lesions (WSL) might be more prone to enamel loss during bracket debonding. This in vitro study compared enamel loss from teeth with (n = 14) and without (n = 14) WSL after polishing with low-speed finishing burs or disks (Sof-Lex, 3M ESPE, St Paul, Minn). Debonded surfaces were analyzed with a contact stylus profilometer, and digitized data were compared with baseline readings by using AnSur NT software (Regents, University of Minnesota, Minneapolis, Minn). Specimen surfaces were also examined with a scanning electron microscope. Two-way analysis of variance was performed to analyze the data. In teeth without WSL, the volume losses were 0.16 mm(3) for the bur group and 0.10 mm(3) for the disk group; the mean maximum depths were 47.7 microm for the bur group and 54.3 microm for the disk group. In teeth with WSL, the volume losses were 0.06 and 0.17 mm(3), and the mean maximum depths were 35.1 and 48.7 microm for the bur and disk groups, respectively. There were no significant differences in enamel loss between the 2 groups of teeth without WSL (P =.12). However, in teeth with WSL, the burs removed less enamel than the disks (P = 0.006). Scanning electron microscope examination showed that any damage on the enamel surface was usually located in the cervical third of the teeth. On most specimens, even though tooth surfaces appeared resin-free to the naked eye, there were remnants of it. The differences between groups were so small that they might be clinically insignificant.  相似文献   
5.
OBJECTIVE: Gastric paresis in traumatic brain injury (TBI) hinders the effectiveness of enteral support in this patient group. In this study we have investigated the effect of metoclopramide on gastric emptying in TBI patients. METHOD: In this prospective, randomized, controlled, double-blind study, 19 TBI patients with Glasgow Coma Scale scores of 3-11 were included. In all patients, enteral nutrition was commenced with a nasogastric feeding tube within 48 hours of trauma. Patients were randomized into two groups. In the metoclopramide (M) group, 10 mg metoclopramide was delivered intravenously three times daily for 5 days. In the control (C) group, an equal volume of saline was administered. Besides demographics, gastric emptying according to a paracetamol absorption test at days 0 and 5, time to reach target nutritional requirements, gastric residues, intolerance to feeding, nutritional complications, and clinical outcomes were recorded for each patient. RESULTS: The gastric residue rates were 2.7+/-7.4 mL and 8.1+/-17.7 mL per 100 patient days for groups C and M respectively (p=0.408). Similarly, feeding intolerance and complication rates did not significantly differ between groups C and M, (respectively p=0.543 and 0.930). Gastric emptying parameters also were similar between the study groups. CONCLUSION: We were unable to document any advantage to using metoclopramide in TBI patients. Simple intragastric enteral feeding with close monitoring of the possible complications seems to be sufficient with acceptable morbidity rates.  相似文献   
6.
Glomerular changes in BK virus nephropathy   总被引:10,自引:0,他引:10  
This study seeks to define the glomerular changes that are associated with human BK virus nephropathy (BKVN). It is based on histopathologic review of 124 biopsies showing light-microscopic changes of viral nephropathy. The diagnosis of BKVN was confirmed by immunohistochemistry or by in situ hybridization. Histological lesions were scored by the Banff 97 criteria for renal allograft pathology and were correlated with clinical parameters. Viral cytopathic effect in the parietal Bowman's capsular epithelium was seen in 21/124 (17%) biopsies. Immunohistochemistry showed infection of Bowman's capsular epithelium in an additional 15/124 (12%) biopsies. Crescents were found in 15/124 (12%) samples. Glomerulitis exceeding grade Banff g1 was only occasionally shown (4/124=3% biopsies). Other pathologic lesions documented include mild increase in mesangial matrix in 23% biopsies, aneurysmal dilatation of glomerular capillaries in 28%, ischemic glomerulopathy in 62%, and chronic transplant glomerulopathy graded as mild (cg1) in 62% of biopsies and as moderate (cg2) in 2/124 (1.9%) biopsies. These findings show that infection of the glomerular epithelium cells can occur in a subset of patients with BKVN, most often in biopsies with high viral load in the tubular epithelium. Isolated crescents can occur in BKVN biopsies, but rapidly progressive glomerulonephritis is not observed. Two biopsies showed electron-dense deposits on ultrastructural examination, but a cause and effect relationship to BK virus infection could not be established.  相似文献   
7.
Cholecystokinin-tetrapeptide (CCK-4) induces panic attacks both in patients with panic disorder (PD) and healthy volunteers. It has been shown that panic elicited by CCK-4 is improved after treatment with antidepressants. Moreover, a reduction of CCK-4-induced panic has also been demonstrated after treatment with lorazepam in single subjects and after selective GABAergic treatment with vigabatrin. Although benzodiazepines are widely used as anxiolytics, no controlled study on the effects of benzodiazepines on CCK-4-induced panic symptoms is available so far. Therefore, we investigated the effects of alprazolam and placebo on CCK-4-induced panic symptoms in a double-blind, placebo-controlled study. A total of 30 healthy subjects were challenged with 50 microg CCK-4. Out of these 30 subjects, 26 showed a marked panic response to CCK-4. Subjects were rechallenged after a 7-day interval and treated with 1 mg alprazolam or placebo 1 h prior to the second CCK-4 challenge. Panic was assessed using the acute panic inventory (API) and a DSM-IV-derived panic symptom scale (PSS). Moreover, the number of reported symptoms and self-rated anxiety and arousal were recorded. We found a significant reduction of the API and PSS scores and of the number of reported symptoms compared to placebo. Moreover, compared to placebo the CCK-4-induced ACTH and cortisol release were significantly attenuated during the CCK-4 challenge after alprazolam treatment. However, also placebo treatment reduced CCK-4-induced anxiety and HPA-axis activation to a certain extent. In conclusion, our data show that alprazolam reduces CCK-4-induced panic, which supports the hypothesis of a possible interaction between the GABA and the CCK system.  相似文献   
8.
In hypersensitive reactions to native L‐asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG‐ASP) is preferred. Anaphylaxis with PEG‐ASP is rare. An 8‐year‐old girl and a 2.5‐year‐old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L‐asparaginase hypersensitivity and substitution with PEG‐ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG‐ASP infusion. Both patients developed anaphylaxis with peg‐asparaginase. These are the first reported cases of anaphylactic reaction to PEG‐ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG‐ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions.  相似文献   
9.
10.
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