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   334篇
  免费   24篇
  国内免费   11篇
儿科学   2篇
基础医学   38篇
口腔科学   39篇
临床医学   26篇
内科学   87篇
神经病学   13篇
特种医学   28篇
外科学   61篇
预防医学   14篇
眼科学   1篇
药学   19篇
肿瘤学   41篇
  2022年   3篇
  2021年   3篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   5篇
  2016年   12篇
  2015年   8篇
  2014年   8篇
  2013年   9篇
  2012年   14篇
  2011年   13篇
  2010年   3篇
  2009年   4篇
  2008年   12篇
  2007年   9篇
  2006年   14篇
  2005年   12篇
  2004年   16篇
  2003年   9篇
  2002年   13篇
  2001年   7篇
  2000年   13篇
  1999年   11篇
  1998年   15篇
  1997年   6篇
  1996年   4篇
  1995年   7篇
  1992年   7篇
  1991年   7篇
  1990年   9篇
  1989年   9篇
  1988年   16篇
  1987年   10篇
  1986年   8篇
  1985年   6篇
  1984年   7篇
  1983年   6篇
  1982年   3篇
  1979年   6篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1974年   2篇
  1973年   7篇
  1971年   2篇
  1970年   2篇
  1969年   3篇
  1968年   2篇
  1967年   3篇
排序方式: 共有369条查询结果,搜索用时 31 毫秒
11.
12.
13.

Summary

Background and objectives

Dialysis patients show “reverse causality” between serum cholesterol and mortality. No previous studies clearly separated the risk of incident cardiovascular disease (CVD) and the risk of death or fatality after such events. We tested a hypothesis that dyslipidemia increases the risk of incident atherosclerotic CVD and that protein energy wasting (PEW) increases the risk of fatality after CVD events in hemodialysis patients.

Design, setting, participants, & measurements

This was an observational cohort study in 45,390 hemodialysis patients without previous history of myocardial infarction (MI), cerebral infarction (CI), or cerebral bleeding (CB) at the end of 2003, extracted from a nationwide dialysis registry in Japan. Outcome measures were new onsets of MI, CI, CB, and death in 1 year.

Results

The incidence rates of MI, CI, and CB were 1.43, 2.53, and 1.01 per 100 person-years, and death rates after these events were 0.23, 0.21, and 0.29 per 100 person-years, respectively. By multivariate logistic regression analysis, incident MI was positively associated with non-HDL cholesterol (non–HDL-C) and inversely with HDL cholesterol (HDL-C). Incident CI was positively associated with non–HDL-C, whereas CB was not significantly associated with these lipid parameters. Among the patients who had new MI, CI, and/or CB, death risk was not associated with HDL-C or non–HDL-C, but with higher age, lower body mass index, and higher C-reactive protein levels.

Conclusions

In this hemodialysis cohort, dyslipidemia was associated with increased risk of incident atherosclerotic CVD, and protein energy wasting/inflammation with increased risk of death after CVD events.  相似文献   
14.
A retrospective study of 75 patients with advanced inoperable gastric cancers, referred to the National Cancer Center Hospital between 1962 and 1982, was performed. According to the Borrmann classification based on X ray findings, Type 1 was found in 3 patients, Type 2 in 5, Type 3 in 40, and Type 4 in 15. Twelve patients could not be classified. The histological type was papillary adenocarcinoma in 7 patients, tubular adenocarcinoma in 23, mucinous carcinoma in 6, poorly differentiated adenocarcinoma in 14, signet ring cell carcinoma in 12 and others in 13. The site of remote metastasis in 19 patients was Virchow's lymph node in 8 patients, Douglas pouch in 3, liver and lung in 2 each and others in 4. All patients were treated by a either telecobalt 60 unit or a linear accelerator using 6 Mv photon and the total dose to primary lesion was 4000 cGy in 5 weeks to 7000 cGy in 8-9 weeks. Complete response (CR) was achieved in 6 patients or 8.0%, partial response (PR) in 46 or 61.3%, and no change (NC) in 23 or 30.7%. The response rate based on the sum of CR and PR was about 70%. The 50% survival period in months was 26.5, 7.3, and 3.2, respectively for patients with CR, PR, and NC. For the response of advanced gastric cancer to chemotherapy in the National Cancer Center Hospital, the combined use of UFT and Mitomycin C gave the highest rate, 46%. As for as local response is concerned, the response rate to radiation was 70%, a better result than that of chemotherapy alone.  相似文献   
15.
PURPOSE: To evaluate the efficacy and toxicity of high-dose thoracic radiotherapy (TRT) alternating with chemotherapy (CH) for unresectable stage III non--small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Forty-one patients received TRT with 1.5 Gy twice daily, 5 days a week, on weeks 1, 2, 5, 6, and 9, up to a total dose of 66 to 72 Gy, alternating with cisplatin 80 mg/m(2) on day 1 and vindesine 3 mg/m(2) on days 1 and 8, repeated every 4 weeks, for two or three courses beginning on week 3. RESULTS: The median (range) total dose of TRT and number of CH courses were 72 Gy (16.5 to 72 Gy) and three (zero to three), respectively. Delay in TRT > or = 5 days was observed in 24 (75%) of 32 patients who completed the projected treatment, due to leukopenia in 12, esophagitis in seven, infection in two, and other causes in three patients. Partial responses were obtained in 36 patients (88%). The median survival time and 3- and 5-year survival rates were 18.4 months, 24%, and 10%, respectively. Grade 3 or 4 leukopenia and esophagitis developed in 32 and seven patients, respectively. Grade 3 or 4 late esophageal toxicity developed in two patients. CONCLUSION: Alternating high-dose TRT and CH for stage III NSCLC produced a high response rate with median and long-term survival comparable to prior trials utilizing standard approaches in this population. Acute and late esophageal toxicity was observed and interruption of TRT was required in most of the patients.  相似文献   
16.
The effects of inhalation anesthetics, nitrous oxide (N2O) and halothane, on the expression of c-Fos protein evoked by formalin injection were studied in the spinal cord in the rat. The expression of c-Fos protein was detected by immunocytochemistry following the injection of formalin (5%, 100 μl) into the plantar surface of the left hindpaw. After 15 min of halothane (F) anesthesia, the anesthetics was switched to 40% or 70% of N2O, 0.5% or 1.5% of F or room air (for control) immediately following the formalin injection. Two hours later the rats were sacrificed and perfused. Sections of the L4 level of spinal cord were immunostained with anti c-Fos antibody. We counted the number of Fos-like immunoreactive (FLI) cells in every specific lamina as follows; superficial layer (laminae I and II), nucleus proprius (laminae III and IV), neck of the dorsal horn (laminae V and VI) and ventral gray (laminae VII–X). Then we compared the results of each category of sample. Both N2O and halothane suppressed the expression of c-Fos in the neck of the dorsal horn and ventral gray in a dose-dependent manner, but no effects were seen at the superficial layer or nucleus proprius. Suppression of c-Fos expression was greater under N2O than halothane anesthesia. This finding suggests that N2O had a stronger analgesic effect than halothane. The current study indicates that inhalation anesthetics do not act equally on every kind of spinal neurons. Both N2O and halothane have effects on spinal neurons in the deeper layers but not on the neurons existed in laminae I–II, some of which directly receive noxious inputs. Pretreatment with 2 mg/kg of naloxone, which completely reversed the effects of morphine, did not alter the effect of 70%N2O, suggesting that the analgesic effect of N2O is not mediated by an intrinsic opioid mechanism at the spinal cord level. ©1977 Elsevier Science B.V. All rights reserved.  相似文献   
17.
18.
Rising demand for islet transplantation will lead to severe donor shortage in the near future, especially in countries where cadaveric organ donation is scarce. We undertook a successful transplantation of living-donor islets for unstable diabetes. The recipient was a 27-year-old woman who had had brittle, insulin-dependent diabetes mellitus for 12 years. The donor, who was a healthy 56-year-old woman and mother of the recipient, underwent a distal pancreatectomy. After isolation, 408 114 islet equivalents were transplanted immediately. The transplants functioned immediately and the recipient became insulin-independent 22 days after the operation. The donor had no complications and both women showed healthy glucose tolerance. Transplantation of living-donor islets from the distal pancreas can be sufficient to reverse brittle diabetes.  相似文献   
19.
A series of novel 26-substituted milbemycin A4 derivatives was synthesized from 5-O-t-butyldimethylsilyl-26-hydroxymilbemycin A4 prepared by selenium dioxide oxidation of 5-O-t-butyldimethylsilyl-milbemycin A4. Their acaricidal activities were assessed against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae) on the primary leaves of cowpea plants (Vigna sinesis Savi species) by spraying.  相似文献   
20.
The purpose was to evaluate the intramuscular reperfusion response characteristics associated with repeated isometric contractions in normal human masseter. Intramuscular blood volume was quantified with a near-infrared spectroscopic device that measured the total haemoglobin (Hb) concentration in the muscle. Electromyographic (EMG) activity from the masseter and total bite forces were also recorded. Sixteen healthy volunteers, eight females and eight males, without masticatory muscle pain participated. They were asked first to clench their teeth for as long as possible at 50% of their maximum voluntary contraction (MVC). This was followed by a 60s rest and then immediately by a standard clenching task (50% MVC for 30s) and a 60s recovery period, immediately after which they were asked to repeat exactly the same procedure, with a final 5 min recovery period after the second 30s contraction. Bite force, EMG and Hb concentration were measured continuously and the duration of the two endurance tasks and the amplitudes of all recorded signals were compared (first trial versus second trial). Specifically, the difference between the lowest Hb (trough) seen during the standardised 30s contractions and the highest (peak) seen just after them was assessed. The trough-to-peak difference in Hb concentration of the second standard contraction task was significantly smaller than that of the first standard task (P<0.05, paired t-test). These data show that with sustained effort the post-contraction vasodilatory reperfusion responses of the human masseter are diminished, suggesting a progressive desensitisation of the vasodilatory system.  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