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   775篇
  免费   38篇
  国内免费   6篇
耳鼻咽喉   4篇
儿科学   10篇
妇产科学   12篇
基础医学   109篇
口腔科学   14篇
临床医学   55篇
内科学   107篇
皮肤病学   52篇
神经病学   14篇
特种医学   124篇
外科学   154篇
综合类   15篇
预防医学   23篇
眼科学   6篇
药学   60篇
中国医学   4篇
肿瘤学   56篇
  2022年   4篇
  2021年   10篇
  2020年   10篇
  2019年   12篇
  2018年   10篇
  2017年   6篇
  2016年   8篇
  2015年   16篇
  2014年   27篇
  2013年   30篇
  2012年   50篇
  2011年   59篇
  2010年   32篇
  2009年   37篇
  2008年   51篇
  2007年   49篇
  2006年   43篇
  2005年   42篇
  2004年   47篇
  2003年   32篇
  2002年   33篇
  2001年   29篇
  2000年   32篇
  1999年   17篇
  1998年   7篇
  1997年   10篇
  1996年   5篇
  1994年   4篇
  1992年   10篇
  1991年   6篇
  1990年   8篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   3篇
  1977年   2篇
  1975年   4篇
  1974年   4篇
  1973年   5篇
  1972年   3篇
  1971年   5篇
  1970年   6篇
  1969年   4篇
  1968年   4篇
  1967年   3篇
  1966年   9篇
  1963年   3篇
排序方式: 共有819条查询结果,搜索用时 15 毫秒
21.
Abdominal Radiology - While the typical imaging features of the more common RCC subtypes have previously been described, they can at times have unusual, but distinguishing features. Rarer renal...  相似文献   
22.
Summary This report documents the association of metastatic colonic adenocarcinoma and hypoglycemia occurring in a 40-year-old female with long-standing ulcerative colitis. Although there was extensive replacement of liver parenchyma by metastases, minimal impairment of liver-cell function and the sequence of clinical events indicated that the hypoglycemia was primarily due to the widespread neoplasm and not to hepatic insufficiency. Tumor analysis by the radioimmunoassay method failed to identify the presence of insulin. To our knowledge, this is the first report of the association of chronic ulcerative colitis, colonic adenocarcinoma and hypoglycemia.The authors wish to thank Dr. D. H. Law for his helpful comments and criticism and Mrs. Mildred Hale for her secretarial assistance.  相似文献   
23.
Antinuclear antibodies are present in most patients receiving procainamide. To ascertain whether IgG antiguanosine antibodies are associated with the development of the symptoms of systemic lupus erythematosus, we compared the levels of these antibodies in the sera of 65 patients receiving procainamide: 18 with procainamide-induced symptoms and 47 asymptomatic patients. Antinuclear antibodies measured by immunofluorescence were present in the 18 patients with drug-induced symptoms but also in 24 asymptomatic patients. Similarly, elevated serum levels of antibodies to single-stranded DNA were found in 15 patients with symptoms and in 20 asymptomatic patients. In contrast, levels of IgG antiguanosine antibodies were elevated in 15 patients with drug-induced symptoms, but in only 3 asymptomatic patients. Antiguanosine antibodies binding to single-stranded DNA were found primarily in patients with arthritis, pleuritis, and pericarditis. These results suggest a strong association between IgG antiguanosine antibodies and major manifestations of procainamide-induced systemic lupus erythematosus.  相似文献   
24.

Objective

To assess the effects of positive cardiac genetic diagnoses, ICD discharges, and arrhythmias on measures of psychological well-being.

Methods

Fifty-eight adults with prior cardiac genetic testing were enrolled. Patient well-being was determined using the SF-36 (QoL), HADS-A and HADS-D (anxiety/depression), and IPQ-R (patients' perceptions of illness). Patients with positive and negative cardiac genetic test results were compared using non-parametric statistics.

Results

Genetic testing yielded 76% with a positive diagnosis and 29% reported an ICD shock. QoL assessments (n = 33) were within normal ranges (mean of 50) with the exceptions of general health (44.1 ± 12.2, p < 0.01) and bodily pain (55.1 ± 9.1, p < 0.01) domains, but only the bodily pain domain showed differences between those with positive and negative cardiac genetic test results. Subjects with ICD discharges had higher scores than those without shocks in consequential and emotional IPQR subscales as well as greater perceived risks of experiencing a serious cardiac event, developing additional symptoms, or limitations in daily activities.

Conclusion

Positive genetic results did not negatively impact patient well-being with the exception of the bodily pain domain of the SF-36.  相似文献   
25.
26.
To increase the energy density of today''s batteries, studies on adding Si-based materials to graphite have been widely conducted. However, adding a Si-based material in the slurry mixing step suffers from low distribution due to the self-aggregation property of the Si-based material. Herein, a hierarchical structure is proposed to increase the integrity by using APS to provide a bonding effect between graphite and SiOx. Additionally, to endow a protection layer, carbon is coated on the surface using the CVD method. The designed structure demonstrates enhanced integrity based on electrochemical performance. The MSG (methane decomposed SiOx@G) electrode demonstrates a high ICE of 85.6% with 429.8 mA h g−1 initial discharge capacity. In addition, the MSG anode has superior capacity retention (89.3%) after 100 cycles, with enhanced volumetric expansion (12.7%) after 50 cycles. We believe that the excellent electrochemical performance of MSG is attributed to increased integrity by using APS (3-aminopropyltrimethoxysilane) with a CVD carbon coating.

This study demonstrates the increased integrity of graphite–SiOx–C hierarchical structure using 3-aminopropyltrimethoxysilane (APS). Furthermore, the carbon coating contributes to elec-trode stability.  相似文献   
27.
Glucagon-like peptide 2: a new treatment for chemotherapy-induced enteritis   总被引:5,自引:0,他引:5  
BACKGROUND: Glucagon-like peptide 2 (GLP-2) is a recently identified intestinal epithelium-specific growth factor that has been shown to reduce the severity of inflammatory disorders of the intestine in rodent models. We hypothesized that GLP-2 administration would be beneficial in chemotherapy-induced enteritis either by preventing injury or by promoting recovery. MATERIAL AND METHODS: Rats received no drug (control), chemotherapy alone [5-fluorouracil (5-FU), 190 mg/kg, ip] (Chemo), 5-FU followed by 3 days of GLP-2 analog (ALX-0600, 0.1 microg, sc twice daily) (CH-G), or GLP-2 analog for 6 days prior to 5-FU and for 3 days afterward (G-CH-G). Animals were pair fed. Rats received 5-bromo-2-deoxyuridine (Br-dU, 50 mg/kg, 2.5 h prior to sacrifice on Day 3 postchemotherapy) for immunohistochemical assessment of cellular proliferation. RESULTS: Chemotherapy induced significant reductions in body weight, villus height, and crypt depth compared with controls. Intestinal wet weight, villus height, and crypt depth were significantly higher for the CH-G group compared with the Chemo group. The CH-G group also showed a significant improvement in villus height compared with the G-CH-G group. Crypt depth, but not jejunal wet weight or villus height, was significantly improved in the G-CH-G group compared with the Chemo group. The percentage of Br-dU-labeled cells in the intestinal crypts did not differ among the groups. CONCLUSIONS: These results suggest, for the first time, that GLP-2 treatment initiated after chemotherapy administration enhances intestinal recovery. In contrast, GLP-2 treatment initiated prior to chemotherapy administration to prevent injury has less beneficial effect. GLP-2 administration may be beneficial to patients suffering from chemotherapy-induced enteritis.  相似文献   
28.
Limited therapeutic options are available for vancomycin intermediate-resistant Staphylococcus Epidermidis (VISE) infections and no optimum therapy has been established. We report a case of VISE skull osteomyelitis that was successfully treated with linezolid. The patient was a 53-year-old man who presented with headache, nausea and dysphasia. Brain computerized tomography (CT) demonstrated a subdural hematoma in the left hemisphere. Craniotomy and hematoma evacuation was performed and he showed good recovery despite a scalp wound infection caused by methicillin-resistant Staphylococcus aureus (MRSA). The organism isolated from the scalp wound was sensitive to vancomycin. The patient was treated with intravenous vancomycin for 44 days. However, he showed a high fever, persistent positive methicillin-resistant Staphylococcus Epidermidis (MRSE) blood cultures, and a deteriorating clinical status. He underwent infected skull bone flap removal and linezolid treatment for 35 days. During one year of follow up, he has not had any further episodes of osteomyelitis or fever. Linezolid has shown to be effective agent to eradiate osteomyelitis caused by VISE.  相似文献   
29.
We tested the hypothesis that angiotensin-converting enzyme (ACE) and angiotensinogen gene polymorphism influence the incidence, development and outcome of preeclampsia. Subjects were recruited from 90 Korean patients with preeclampsia during pregnancy and 98 age-matched controls. After isolation of DNA, polymerase chain reactions (PCR) were carried out to detect polymorphism of the ACE and angiotensinogen. M235T and T174M genotypes of angiotensinogen were determined by digestion with restriction enzyme endonuclease Tth 111-I and NCo I, respectively. The frequency of DD genotype was significantly greater in preeclampsia (0.36) than in controls (0.14) (p<0.05). The frequency of D allele was 0.55 in preeclampsia and 0.40 in controls (p<0.05). There were no differences in the onset of preeclampsia and pregnancy outcomes according to the ACE genotypes. There was no difference in the frequency of a allele of angiotensinogen M235T between the groups (0.79:0.78 in preeclampsia : controls). The frequency of T allele of angiotensinogen T174M gene was slightly increased, but not significantly, in preeclampsia (0.11) than in controls (0.07). In a multivariate analysis, only ACE genotype was associated with the development of preeclampsia (beta=0.27, p=0.05). In conclusion, a molecular variant of ACE, but not angiotensinogen, gene is associated with preeclampsia in Korean women.  相似文献   
30.
Thioredoxin (TRx) is a small redox protein that plays significant roles in protection against oxidative stress and in cell homeostasis by maintaining oxidized proteins in a reduced state. Here, we describe the isolation and characterization of a full-length TRx cDNA sequence from manila clam, Ruditapes philippinarum and named it as RpTRx. The full length sequence consists of 1416 bp with an open reading frame of 318 bp encoding for 106 amino acids. RpTRx protein harbors evolutionarily-conserved TRx active site 32WCGPC36. Phylogenetic analysis revealed a close proximity of RpTRx with the orthologue in Japanese scallop, Chlamys farreri. RpTRx was found to be constitutively expressed in hemocyte, gill, mantle, foot and siphon indicating a general role in physiological processes in various tissues. With regard to a potential role in immune responses, the RpTRx mRNA was found to be up-regulated in hemocytes after bacterial (Vibrio tapetis) and lipopolysaccharide (LPS) challenge at 3 h post-infection (p.i.); a wavering increase was observed up to 96 h p.i. for LPS challenge and 48 h p.i. for bacterial challenge. Thus, RpTRx may function as an intracellular antioxidant to protect the cells against ROS induced by LPS and bacterial challenges. Indeed, when recombinant RpTRx protein (rRpTRx) was over-expressed in Escherichiacoli Rosetta gamiTM (DE3) cells, it was able to scavenge free radicals and protect super-coiled DNA from oxidative damage induced by a metal-ion catalyzed oxidation reaction. In summary, RpTRx plays an essential role in cellular defense and maintenance of homeostasis in the manila clam.  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