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   2805篇
  免费   245篇
  国内免费   48篇
耳鼻咽喉   9篇
儿科学   64篇
妇产科学   57篇
基础医学   255篇
口腔科学   573篇
临床医学   236篇
内科学   471篇
皮肤病学   44篇
神经病学   50篇
特种医学   81篇
外国民族医学   1篇
外科学   305篇
综合类   250篇
预防医学   95篇
眼科学   27篇
药学   126篇
  1篇
中国医学   46篇
肿瘤学   407篇
  2024年   9篇
  2023年   93篇
  2022年   151篇
  2021年   179篇
  2020年   162篇
  2019年   163篇
  2018年   168篇
  2017年   111篇
  2016年   112篇
  2015年   99篇
  2014年   183篇
  2013年   157篇
  2012年   118篇
  2011年   153篇
  2010年   103篇
  2009年   126篇
  2008年   111篇
  2007年   96篇
  2006年   91篇
  2005年   80篇
  2004年   65篇
  2003年   58篇
  2002年   57篇
  2001年   45篇
  2000年   38篇
  1999年   39篇
  1998年   30篇
  1997年   36篇
  1996年   11篇
  1995年   21篇
  1994年   25篇
  1993年   11篇
  1992年   15篇
  1991年   24篇
  1990年   4篇
  1989年   14篇
  1988年   14篇
  1987年   14篇
  1986年   5篇
  1985年   29篇
  1984年   14篇
  1983年   14篇
  1982年   13篇
  1981年   20篇
  1980年   3篇
  1979年   7篇
  1978年   2篇
  1976年   2篇
  1973年   1篇
  1972年   1篇
排序方式: 共有3098条查询结果,搜索用时 15 毫秒
21.
This study is based on an evaluation of patients' opinions of their dentures by means of a questionnaire. The patients had been provided with complete dentures at a university clinic. Of the original sample (n = 139) a test group of 92 patients remained available for the actual study 5 yr after treatment. The replies in the questionnaire were subjected to statistical processing and interpretation. Six clusters could be defined and these were introduced as "scales" representing the patients' score on a specific type of complaint. Apart from the six scales a score was achieved for each patient's overall satisfaction. The correlations between the various scales were calculated with the aid of a computer program. Finally, cross-tabulation was used to see if any significant (inter)correlations could be proved between complaints, satisfaction, and some of the patients' social data. It could be concluded that a correlation exists between complaints of pain and of functional aspects on the one hand and vague complaints on the other hand. There is also a correlation between complaints of looseness of the maxillary denture and complaints about aesthetic factors. Well-fitting and well-functioning dentures, absence of pain, and a socially acceptable appearance contribute much to the patients' satisfaction with dentures. Social variables such as type of insurance (public or private) and marital status influence denture appreciation to a certain extent.  相似文献   
22.
Cortical metabolites and regional cerebral intracellular pH (pHi) were measured in normoglycemic (NM), acute hyperglycemic (AH), and chronic hyperglycemic (CH, 2 week duration, streptozotocin-induced) Wistar rat brains during cardiac arrest and resuscitation. During total ischemia in AH and CH rats (plasma glucose approximately 30 mM), cortical ATP, PCr, glucose, and glycogen all fell significantly as expected. Lactate levels increased dramatically in association with a concomitant intracellular acidosis. Although lactate reached higher concentrations in AH and CH than NM, pHi was significantly lower only in the AH group. With 5 min of reperfusion, all groups recovered to near baseline in all variables, though lactate remained elevated. In a separate aspect of the study, animals from each experimental group were allowed to recover for 4 days following resuscitation, with outcome being gauged by mortality rate and hippocampal CA1 neuron counts. NM survival rate was significantly better than AH and CH. In particular, no CH rats survived for 4 days despite rapid initial recovery. After 4 days, the AH group had suffered significantly greater CA1 neuron loss than the NM rats. In summary, our research identified differences in intra-ischemic acid-base status in the two hyperglycemic groups, suggesting that chronic hyperglycemia may alter the brain's buffering capacity. These observations may account for differences between acutely and chronically hyperglycemic subjects regarding outcome, and they suggest that factors other than hydrogen ion production during ischemia are responsible for modulating outcome.  相似文献   
23.
报道了流行性感冒病毒抗体的制备及其抗体价的检测方法。利用鼠、兔对流行性感冒(IFV)抗原的免疫反应制备抗体;酶联免疫法(ELISA)测定抗体价。结果显示:Freund佐剂与抗原的混合乳液,具有流行性感冒病毒的抗原特异性,且能够增强抗原的免疫原性,并改变宿主的免疫反应原性。  相似文献   
24.
25.
The value of consolidation therapy in advanced epithelial ovarian carcinoma patients is controversial. The aim of the present study was to assess the long-term survival of patients with a pathologically confirmed complete remission who had consolidation by single-dose, whole-abdominopelvic radiotherapy. Of 96 histologically confirmed stage II-IV epithelial ovarian carcinoma patients who underwent cytoreductive surgery followed by high-dose, platin-based chemotherapy, 57 were in complete clinical remission at the end of therapy and 50 underwent a second-look laparotomy. The study group comprises 32 consecutive patients who had no pathological evidence of disease and who received 800 cGy single-dose, whole-abdominal radiotherapy by an 8 MEV linear accelerator in a single fraction. The absolute 5-year survival and the actuarial 10-year survival were 78.7 and 63.3%, respectively. The survival was significantly better in patients who had < or =2 cm residual disease at the completion of the original operation. No severe postradiation complications were encountered. Mild complications were seen in three (9.4%) patients. Our data indicate a favorable long-term survival of patients with a negative second-look laparotomy who had consolidation with single-dose, whole-abdominal radiotherapy. These results seem to suggest that a collaborative, prospective, randomized multiarm study is indicated to solve the controversial issue of consolidation therapy.  相似文献   
26.
目的探讨种植体磁性附着体固位全口义齿的临床应用。方法下颌牙槽嵴严重萎缩吸收的全口义齿患者,在下颌骨前牙区骨内植入2枚种植体,4个月后制作覆盖全口义齿,磁铁安装在义齿面内。衔铁固定在种植体上,利用磁性附着体的磁吸力使全口义齿固位在牙槽骨上。结果种植体磁性固位全口义齿固位良好,患者说话和咀嚼效果满意。结论种植体磁性附体固位全口义齿。对于牙槽嵴严重萎缩吸收的患者,能明显示改善固位和咀嚼效果。  相似文献   
27.
BACKGROUND: The role of anthracyclines has been extensively studied in adjuvant chemotherapy, but much less in the primary chemotherapy of early breast carcinoma. This study, comparing CMF (cyclophosphamide, methotrexate, 5-fluorouracil) with the rotational anthracycline-containing regimen CMFEV (CMF plus epirubicin and vincristine) administered as primary chemotherapy, demonstrated a significant increase in clinical complete response in premenopausal women. We report the long-term results. PATIENTS AND METHODS: Two hundred and eleven patients with stage I or II palpable breast carcinoma and a tumour diameter of >2.5 cm were randomised to receive CMF or CMFEV for four cycles before surgery. After surgery, the patients in both arms received adjuvant CMF for three cycles. RESULTS: In the study population as a whole, there was a non-significant 20% reduction in mortality and relapse rates in the CMFEV arm. However, the effect of the experimental regimen was only found in premenopausal patients, especially in terms of relapse-free survival (P=0.07) and locoregional relapse-free survival (P=0.0009), thus mirroring the effect on response rates. After 10 years, the proportions of premenopausal patients free from locoregional relapse as a first event in the CMF and CMFEV groups were 68% and 97%, respectively. No relevant differences were found in postmenopausal patients. CONCLUSION: The overall results of this study showed that the greater activity of the experimental anthracycline-containing combination over CMF as primary chemotherapy in premenopausal patients translated into long-term effects in the same subgroup.  相似文献   
28.
上颌全口义齿铸造腭托后堤区的网状设计与临床观察   总被引:2,自引:0,他引:2  
目的:评价上颌全口义齿铸造金属腭侧基托后堤区网状设计的临床效果。方法:采用刮除石膏的方法形成后堤区,在上颌基托硬腭区采用金属板设计,牙槽嵴及基托后缘10mm(后堤区)范围采用金属网加强塑料基托设计。在戴牙后1个月对上颌义齿固位效果进行评价。对由于后堤区封闭不佳造成的固位不良者,进行后堤区重衬后再次评价。结果:158例患者中,139例固位佳,15例固位一般,4例固位差。单纯由后堤区边缘封闭不良造成的固位一般11例,固位差3例,经后堤区重衬后对此14例再次评价,固位佳9例,固位一般5例。结论:上颌全口义齿铸造金属腭侧基托后堤区的网状设计,既保持了常规设计的优点,又克服了其不能重衬的缺点,减少了全口义齿的失败率。  相似文献   
29.
和血祛风冲剂对类风湿关节炎大鼠细胞因子的影响   总被引:11,自引:0,他引:11  
目的:通过对大鼠福氏完全佐剂性关节炎动物模型进行观察,探讨和血祛风冲剂对该动物模型细胞因子的影响。方法:观察和血祛风冲剂不同剂量组与寒湿痹冲剂对大鼠福氏完全佐剂性关节炎动物模型白介素1(IL-1)、肿瘤坏死因子α(TNF-α)、类风湿因子(RF)、免疫球蛋白G、A、M(IgG,IgA,IgM)进行观察。结果;和血祛风冲剂各剂量组及寒湿痹冲剂均有消肿作用,均楫IL-1、TNF-α、RF、IgG水平,对IgG抑制作用前者优于后者。结论:和血祛风冲剂治疗类风湿关节炎的机理 可能是抑制炎性细胞因子及免疫球蛋白的水平。  相似文献   
30.
Abstract

Gestational trophoblastic disease includes complete hydatidiform mole (CHM) or partial hydatidiform mole (PHM) and gestational trophoblastic neoplasia (GTN). Given the very high-curability rate of trophoblastic disease, the risk of further molar pregnancy after CHM or PHM as well as the risk of second primary tumors and fertility compromise after chemotherapy for GTN represent major concerns. The incidence of subsequent molar pregnancy ranges from 0.7 to 2.6% after one CHM or PHM, and is approximately 10% after two previous CHMs. Among patients who have received chemotherapy, there is an increased risk of myeloid leukemia which is mainly related to the cumulative dose of etoposide. Resumption of normal menses occurs in approximately 95% of women treated with chemotherapy, but menopause occurs 3 years earlier compared with those non-treated with chemotherapy. Term live birth rates higher than 70% without increased risk of congenital abnormalities have been reported in these women, and pregnancy outcomes are comparable to those of general population, except a slightly increased risk of stillbirth. Fertility-sparing treatment for placental site trophoblastic tumor is a therapeutic option reserved to highly selected, young women who do not present markedly enlarged uterus or diffuse multifocal disease within the uterus.  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