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   370篇
  免费   41篇
  国内免费   3篇
儿科学   16篇
妇产科学   1篇
基础医学   25篇
口腔科学   2篇
临床医学   31篇
内科学   48篇
皮肤病学   6篇
神经病学   87篇
特种医学   52篇
外科学   43篇
综合类   34篇
预防医学   25篇
眼科学   1篇
药学   26篇
肿瘤学   17篇
  2023年   4篇
  2022年   4篇
  2021年   11篇
  2020年   6篇
  2019年   10篇
  2018年   5篇
  2017年   10篇
  2016年   12篇
  2015年   19篇
  2014年   9篇
  2013年   13篇
  2012年   14篇
  2011年   16篇
  2010年   15篇
  2009年   15篇
  2008年   10篇
  2007年   9篇
  2006年   8篇
  2005年   6篇
  2004年   10篇
  2003年   8篇
  2002年   8篇
  2001年   6篇
  2000年   7篇
  1999年   8篇
  1998年   21篇
  1997年   10篇
  1996年   9篇
  1995年   15篇
  1994年   11篇
  1993年   9篇
  1992年   5篇
  1991年   3篇
  1990年   10篇
  1989年   5篇
  1988年   9篇
  1987年   14篇
  1986年   6篇
  1985年   11篇
  1984年   11篇
  1983年   3篇
  1982年   5篇
  1981年   2篇
  1980年   2篇
  1978年   1篇
  1977年   2篇
  1976年   4篇
  1975年   1篇
  1973年   1篇
  1962年   1篇
排序方式: 共有414条查询结果,搜索用时 15 毫秒
71.
72.
73.
BackgroundCalcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response.CasesWe present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy.ConclusionThis case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward.  相似文献   
74.
Lee KC  Goh WL  Xu M  Kua N  Lunny D  Wong JS  Coomber D  Vojtesek B  Lane EB  Lane DP 《Oncogene》2008,27(5):629-640
The zebrafish has many advantages as a vertebrate model organism and has been extensively used in the studies of development. Its potential as a model in which to study tumour suppressor and oncogene function is now being realized. Whilst in situ hybridization of mRNA has been well developed in this species to study gene expression, antibody probes are in short supply. We have, therefore, generated a panel of anti-zebrafish p53 monoclonal antibodies and used these to study the p53 response in zebrafish embryos. By immunohistochemistry, we show that the exposure of zebrafish embryos to p53-activating agents such as R-roscovitine and gamma-irradiation results in the accumulation of p53 protein in the gut epithelium, liver and pancreas. A combination of R-roscovitine and gamma-irradiation results in massive p53 induction, not only in the pharyngeal arches, gut region and liver but also in brain tissues. Induction of apoptosis and expression of p53 response genes are seen in regions that correspond to sites of p53 protein accumulation. In contrast, although zebrafish tp53(M214K) mutant embryos showed a similar accumulation of p53 protein, a complete lack of a downstream p53-dependent response was observed. In this system the p53 gene is identified as a p53-responsive gene itself. Our results demonstrate that zebrafish p53 protein can readily be induced in embryos and detected using these new antibody tools, which will increase the usefulness of zebrafish as a model in compound-based screening for novel drugs in cancer research.  相似文献   
75.

Background and purpose:

Lipid rafts and caveolae are membrane microdomains with important roles in cell survival signalling involving the Akt pathway. Cholesterol is important for the structure and function of these microdomains. The ginsenoside Rh2 exhibits anti-tumour activity. Because Rh2 is structurally similar to cholesterol, we investigated the possibility that Rh2 exerted its anti-tumour effect by modulating rafts and caveolae.

Experimental approach:

A431 cells (human epidermoid carcinoma cell line) were treated with Rh2 and the effects on cell apoptosis, raft localization and Akt activation measured. We also examined the effects of over-expression of Akt and active-Akt on Rh2-induced cell death.

Key results:

Rh2 induced apoptosis concentration- and time-dependently. Rh2 reduced the levels of rafts and caveolae in the plasma membrane and increased their internalization. Furthermore, Akt activity was decreased and consequently, Akt-dependent phosphorylation of Bad, a pro-survival protein, was decreased whereas the pro-apoptotic proteins, Bim and Bax, were increased upon Rh2 treatment. Unlike microdomain internalization induce by cholesterol depletion, Rh2-mediated internalization of rafts and caveolae was not reversed by cholesterol addition. Also, cholesterol addition did not restore Akt activation or rescue cells from Rh2-induced cell death. Rh2-induced cell death was attenuated in MDA-MB-231 cells over-expressing either wild-type or dominant-active Akt.

Conclusions and implications:

Rh2 induced internalization of rafts and caveolae, leading to Akt inactivation, and ultimately apoptosis. Because elevated levels of membrane rafts and caveolae, and Akt activation have been correlated with cancer development, internalization of these microdomains by Rh2 could potentially be used as an anti-cancer therapy.  相似文献   
76.
SARS病例数的统计学与灰色模型预测效果评价   总被引:3,自引:0,他引:3  
目的探索香港SARS流行的规律,寻找预测SARS短期流行的方法。方法香港每日SARS病例数据(2003年3月11日至2003年6月12日)来源于香港卫生署。采用数理统计学与系统工程学的方法,包括曲线拟合、γ分布、时间序列以及灰色动态GM(1,1)模型等13种方法对每日病例数进行预测。使用预测误差、总体95%可信区间和实际病例数与预测病例数的配对t检验对13种方法的预测效果进行评价。结果对香港SARS日累计病例数预测误差最小的方法分别是:流行高峰期为时间序列、流行下降期为γ分布、流行终末期为灰色模型,其预测误差的中位数分别为0.29%、0.02%和0.03%,且3种方法的预测病例数平均数均不超过实际病例数平均数的95%可信区间。在流行全程预测方面,灰色模型对日累计病例数的预测误差中位数最小,为0.16%;γ曲线和时间序列对日发病数的预测误差中位数较小,分别为0.27%和3.09%。结论时间序列、γ分布和灰色动态GM(1,1)模型对香港SARS流行的短期预测效果较好。  相似文献   
77.
78.
Introduction: Although bleomycin/etoposide/cisplatinum (BEP) chemotherapy is established as the standardtreatment for germ cell tumours, it requires significant experience in administration and toxicity managementto maintain optimal dose intensity. A retrospective review of 30 patients was conducted at UKMMC to studytreatment outcomes. Methods & Materials: Patients with GCTs and treated with at least two cycles of BEPchemotherapy between January 2003 and Oct 2009 were eligible for this study. Patients received 4-6 cycles ofbleomycin 30,000IU IV D1, D8 & D15 and either etoposide 100mg/m2 IV D1- D5 and cisplatin 20mg/m2 IV D1-D5 (5 day BEP regimen) or etoposide 165mg/m2 D1- D3 and cisplatin 50mg/m2 D1-3 (3 day BEP regimen)every three weeks per cycle. All patients received prophylactic granulocyte colony-stimulating factor (GCSF)from days 6 to 10 of each cycle. The overall response rates, 2 year progression-free survival and overall survivalof the whole cohort were assessed. Results: Thirty patients fulfilled the inclusion criteria. Non-seminomatousGCTs comprised 93.3% of cases and gonadal and mediastinal primary sites were the most common. Sixty percentwere classified as IGCCCG poor risk disease. Median follow-up was 26.6 months. The overall response rate(CR+PR) was 70%. The two year PFS and OS were 70% and 66%. There was a significant difference in termsof the overall response rate (85% vs 40%, p = 0.03) and in PFS (94.7% vs 50%, p = 0.003) between gonadaland extragonadal primary sites. Conclusion: It is possible to achieve outcomes similar to those in internationalclinical trials with close monitoring and good supportive care of patients undergoing BEP chemotherapy. Thereis a strong argument for patients with IGCCCG poor prognosis disease to be treated in specialist tertiary centresto optimize treatment outcomes.  相似文献   
79.
Dietary counselling has been identified as one of the nutritional strategies to alleviate cardiometabolic health conditions. Its effectiveness however may vary due to factors such as intensity level and provider while this has not been comprehensively studied. This systematic review and meta-analysis aimed to assess the effects of dietary counselling on the cardiometabolic health in middle-aged and older adults and the sub-group analyses with dietary counselling intensity and the provider were also assessed. Four databases including PubMed, CINAHL Plus with Full Text, Cochrane Library and EMBASE were systematically searched. Data from 22 randomised controlled trials (RCTs) were compiled and those from 9 RCTs were utilised for meta-analysis. Dietary counselling lowered total cholesterol (TC) and fasting blood sugar (FBS) but had no impact on triglycerides (TG) and low-density lipoprotein (LDL). Sub-group analysis revealed significant lowering effect of high intensity dietary counselling for TG (weighted mean difference (WMD): −0.24 mmol/L, 95% confidence intervals (CIs): −0.40 to −0.09), TC (WMD: −0.31 mmol/L, 95% CIs: −0.49 to −0.13), LDL (WMD: −0.39 mmol/L, 95% CIs: −0.61 to −0.16) and FBS (WMD: −0.69 mmol/L, 95% CIs: −0.99 to −0.40) while medium or low intensity dietary counselling did not show favouring effects. Counselling provider showed differential responses on cardiometabolic health between dietitian and all other groups. The findings from this systematic review and meta-analysis suggest that dietary counselling is a beneficial dietary strategy to improve cardiometabolic health in middle-aged and older adults with the emphasis on the counselling intensity.  相似文献   
80.
Insemination with donor spermatozoa is an integral part of infertility treatment. For the last 3 years in our unit, intrauterine insemination with donor spermatozoa (IUID) has been used in preference to vaginal insemination. In this retrospective study, patients were offered an initial course of five single intrauterine inseminations with cryopreserved donor spermatozoa and treatment was then reviewed. A total of 389 patients received 1465 inseminations. In all, 1119 cycles were monitored using luteinizing hormone serum analyses and 346 cycles using the urine home test kits. The clinical pregnancy rate per insemination for the cycles monitored by the serum assay was 18.0% (202/1119) compared with the urine cycles (13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles respectively). The viable clinical pregnancy rate was significantly higher (P <03) for the serum cycles than for the cycles using the urinary monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles monitored by serum assay had a significantly higher cumulative viable clinical pregnancy rate (P <0001) of 70.2% after nine inseminations compared with the urine monitored cycles of 54.8%. The majority of patients opted for the serum cycles, with a minority self-selecting the urine cycles mainly for travelling convenience. The explanation for the significant differences between the viable clinical pregnancy rates per insemination and the cumulative viable clinical pregnancy rates may be due to the sensitivity of the urine home test kit or the patients' interpretation of the result.   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