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   164篇
  免费   9篇
  国内免费   3篇
儿科学   1篇
基础医学   20篇
临床医学   13篇
内科学   28篇
皮肤病学   1篇
神经病学   7篇
特种医学   27篇
外科学   21篇
综合类   2篇
预防医学   5篇
眼科学   17篇
药学   12篇
中国医学   1篇
肿瘤学   21篇
  2023年   1篇
  2022年   3篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2017年   2篇
  2016年   3篇
  2015年   3篇
  2014年   5篇
  2013年   8篇
  2012年   6篇
  2011年   17篇
  2010年   6篇
  2009年   2篇
  2007年   8篇
  2006年   6篇
  2005年   3篇
  2004年   8篇
  2003年   5篇
  2002年   4篇
  2001年   8篇
  2000年   5篇
  1999年   5篇
  1998年   5篇
  1997年   7篇
  1996年   5篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   5篇
  1991年   1篇
  1990年   1篇
  1989年   3篇
  1988年   3篇
  1987年   5篇
  1986年   3篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
  1975年   3篇
排序方式: 共有176条查询结果,搜索用时 15 毫秒
51.
52.
53.
Publicly available toxicity databases serve as the central resource in efforts to develop algorithms for assessing potential chemical toxicity. File standardization and linkage of chemical structures with chemical toxicity information are essential first steps in providing broad access to existing toxicity information, for deriving useful structure-activity relationship (SAR) models, performing analog searches, and estimating the potential toxicity of new chemicals. This review will focus on current efforts to improve structure-linked access to publicly available sources of toxicity information, outlining current web-based resources as well as two new database initiatives for standardizing and consolidating public chemical toxicity information.  相似文献   
54.
The aim of this study was to examine the loss of heterozygosity (LOH) of BRCA1 (17q21) and TP53 (17p13.1) in early-onset breast cancer patients; to correlate biopathological characteristics with molecular alterations; and to investigate the survival of LOH-related cancers.BRCA1 and TP53 LOH were evaluated in 78 early-onset breast cancers (40 years, Group 1) and 80 patients with age <55 years (Group 2). Cases were characterized for multiple biological markers (ER, PR, proliferation index (PI), NEU and p53). LOH was carried out on microdissected paraffin embedded tissues; microsatellites D17S855 (BRCA1) and D17S786 (TP53) were amplified by fluorescent PCR and analyzed by an automated DNA sequencer. Early-onset breast cancers showed a higher frequency of ductal histotype (89,7% vs. 56,3% p<0.001), node-positive (53,8% vs. 38,7%), larger size (p=0.017), higher mitotic rate (p=0.025), higher nuclear and final grade (p=0.01 and p=0.001, respectively). D17S855 LOH was 32,8% in group 1 vs. 21% in group 2; D17S786 LOH was 50,7% vs. 31.3% (p=0.03), respectively. BRCA1 LOH was correlated with higher PI (p=0.032) and higher p53 expression (p<0.001) in group 1 and with higher NEU expression (p=0.028) in group 2. TP53 LOH was correlated with p53 overexpression (p=0.03) in group 1. A worse clinical outcome in early-onset LOH related cancers emerged from follow-up data: TP53 and BRCA1 LOH were associated with a shorter relapse free interval (RFI) (p=0.03) and a poorer overall survival (OS) (p=0.04), respectively. This study underlines different biological profiles in the two age groups investigated, probably reflecting different mechanisms of carcinogenesis. In accordance with adverse histopathological features in early-onset patients, LOH-related cancers have an unfavorable prognosis.  相似文献   
55.
BACKGROUND AND OBJECTIVE: The aim of the present study was to evaluate the correlation between the number of CD34+ cells transfused and the duration of hypoplasia, and the relationship between various CD34+ subsets (CD34+/33-; CD34+/38-; CD34+/ HLA-DR-; CD34+/Thy-1+) and engraftment kinetics in a series of patients with breast cancer treated with high doses of thiotepa and melphalan. DESIGN AND METHODS: We treated 42 consecutive patients: 19 in an adjuvant context (>= 4 positive axillary nodes) and 23 for metastatic disease. A combination of thiotepa 600 mg/m(2) and melphalan 140-160 mg/m(2) was administered as the conditioning regimen. All patients received peripheral blood progenitor cells (PBPC) and growth factors for hematopoietic rescue. RESULTS: In univariate analysis, we found a significant relationship between the number of CD34+ cells reinfused and the time to hematologic recovery and the duration of hospital stay. We observed an inverse correlation between the number of CD34+ cells reinfused and the units of platelets transfused. Cox multivariate analysis confirmed that the number of CD34+ cells reinfused is the most effective predictor of time to hematologic recovery. CFU-GM resulted to be a better predictor of the duration of hospitalization. INTERPRETATION AND CONCLUSIONS: We found a significant relationship between the number of PBPC reinfused and the time to hematologic recovery after high doses of thiotepa and melphalan. In our experience, the numbers of subsets of CD34+ cells infused did not give compared additional information to that provided by the total number of CD34+ cells infused.  相似文献   
56.
Medical photographic documentation is important for professional, research, and ethical concerns. This study analyzed the possible interference that the flash could cause on evaluation of lower eyelid cosmetic results. Standardized photographs with and without flash were taken of 10 patients with dermatochalasis. The photographs were evaluated by 3 independent observers, as before (without flash) and after (with flash) an alternative esthetic treatment of the lower eyelid. The observers rated the overall cosmetic improvement of the lower eyelid photographs on a visual analog scale. The 3 surgeons believed that there was improvement in cosmetic outcome from the first (without flash) to the second (with flash) picture. The results indicate that a simple flash addition in one of 2 consecutive photographs, taken seconds apart, could influence the impression of experienced surgeons on the final outcome of oculoplastic surgeries and may constitute a bias in observer-dependent studies.  相似文献   
57.
Background Benzodiazepines, which are commonly administered perioperatively, can depress immune function. Neutrophil apoptosis plays a central role in the regulation of inflammation. This is particularly important during and after surgery. Aim To examine the effects of benzodiazepines (midazolam and diazepam) on neutrophil apoptosis. Methods Venous blood samples were withdrawn from patients scheduled to undergo elective surgery, (a) immediately prior to, and 10 minutes after administration of midazolam 0.2mg/kg intravenously (n=11) and (b) immediately prior to, and 60 minutes after administration of diazepam 10mg po (n=10). Neutrophil apoptosis was measured by Annexin VFITC after 1 and 12 hours in culture. Results The percentage of apoptotic cells was significantly less after midazolam at 12% (11.9) hours in culture compared to pre-midazolam 29.7% (13.3) (p<0.05). After diazepam, the rates of neutrophil apoptosis were also significantly less after 12 hours in culture (p<0.05). Conclusion Administration of benzodiazepines in clinically relevant doses inhibits neutrophil apoptosis. In the perioperative period, this may influence the inflammatory response to surgery.  相似文献   
58.
Becker  CD; Quenville  NF; Burhenne  HJ 《Radiology》1989,171(1):235-240
Twenty pigs underwent (a) cystic duct occlusion by means of fluoroscopically guided transcatheter endoluminal bipolar radio-frequency (RF) electrocoagulation and (b) gallbladder sclerotherapy with one of two different regimens of ethanol and sodium tetradecyl-sulfate (STS). Serum ethanol levels and hepatic enzyme tests showed no acute toxicity. Postmortem histologic studies showed that the bile ducts beyond the occlusion site remained entirely unaffected in all animals. In three of four animals followed up for 2 weeks, the sclerosants induced necrosis of the gallbladder mucosa, but the adjacent liver, serosa, and blood vessels remained intact. In 13 of 16 animals followed up for 8 weeks, the gallbladder lumen was obliterated by fibrous scar tissue. In the animals treated with 95% ethanol and 3% STS, the gallbladder mucosa was necrotic in all areas after 2 weeks (two of two animals) and eradicated completely after 8 weeks (six of eight animals); the other regimen (70% ethanol plus 1% STS) was somewhat less effective. In this study, the combination of RF-mediated cystic duct occlusion and gallbladder sclerotherapy with ethanol and STS permitted gallbladder ablation in swine without toxic side effects.  相似文献   
59.
A multicentric, prospective phase III study was carried out with the aim of testing the so-called ''worst drug rule'' hypothesis, which suggests the use of an effective but ''less active'' regimen that first eradicates tumoral cells resistant to a second effective and ''more active'' regimen. With respect to this hypothesis, we considered the cisplatin plus vinorelbine regimen (CCDP/VNR) as the more active regimen compared with the non-cisplatin-containing regimen of ifosfamide plus high-dose epirubicin (IFO/EPI). Thus, a randomized study was carried out to compare the sequencial strategy of three cycles of CDDP/VNR followed by three cycles of IFO/EPI with the opposite sequence in advanced non-small-cell lung cancer. A total of 100 consecutive previously untreated patients with stage III-IV non-small-cell lung cancer were centrally randomized in two arms according to stage of disease and the performance status. Patients allocated to arm A received CDDP (100 mg m-2 on day 1) plus VNR (25 mg m-2 i.v. on days 1 and 8) every 21 days for three cycles (step 1) followed, after restaging, by three cycles of IFO (2.5 g m-2 with mesna on day 1) plus high-dose EPI (100 mg m-2 on day 1) every 21 days (step 2). Patients in arm B received the opposite sequence. Type and rates of objective response were evaluated after step 1 and step 2 in agreement with WHO criteria and an intent-to-treat analysis. Patients were also analysed for toxicity patterns, time to progression and survival. After the first three cycles (step 1), overall response rate (ORR), calculated according to an intent-to-treat analysis, was 47% and 21% for arm A and arm B respectively (P = 0.0112). ORR for stage III patients was 55% and 14% for arm A and B respectively (P = 0.0097). In stage IV patients ORR was higher in arm A than in arm B (42% vs 28%) but not statistically significant (P = 0.4). Clinical responses to the shift of chemotherapy (step 2) showed that no patient pretreated with CDDP/VNR and subsequently treated with IFO/EPI showed further response, whereas in the inverse sequence arm CDDP/VNR was able to induce 26% partial response (PR) rate in patients pretreated with IFO/EPI. This difference was statistically significant (P = 0.037). The overall median time to progression (TTP) of arm A and arm B did not significantly differ (6 vs 4 months; P = 0.665). However, median TTP of stage III patients was, respectively, 7 months for arm A and only 3 months for arm B. This difference was statistically significant (P = 0.049). Median overall survival (OS) was 9 and 7 months respectively for arm A and arm B. Despite this trend the difference was not significant (P = 0.328). Median OS of stage III patients showed a statistically significant advantage for arm A over arm B (13 vs 7 months, P = 0.03). In addition, no statistically significant difference in OS was recorded for stage IV patients (both arms 7 months, P = 0.526). Our data do not confirm Day''s ''worst drug rule'' hypothesis, at least in patients with advanced non-small-cell lung cancer treated with the above-mentioned regimens. The combination of CDDP and VNR seems more active, at least in terms of response rate, than the IFO/EPI, which performed poorly.  相似文献   
60.
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