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   605篇
  免费   44篇
  国内免费   3篇
耳鼻咽喉   18篇
儿科学   7篇
妇产科学   28篇
基础医学   107篇
口腔科学   30篇
临床医学   73篇
内科学   104篇
皮肤病学   5篇
神经病学   33篇
特种医学   14篇
外科学   31篇
综合类   27篇
预防医学   78篇
眼科学   18篇
药学   39篇
中国医学   11篇
肿瘤学   29篇
  2023年   17篇
  2022年   39篇
  2021年   54篇
  2020年   28篇
  2019年   30篇
  2018年   41篇
  2017年   30篇
  2016年   22篇
  2015年   34篇
  2014年   32篇
  2013年   41篇
  2012年   48篇
  2011年   50篇
  2010年   41篇
  2009年   18篇
  2008年   29篇
  2007年   42篇
  2006年   13篇
  2005年   6篇
  2004年   13篇
  2003年   4篇
  2002年   5篇
  2001年   2篇
  2000年   1篇
  1997年   1篇
  1994年   3篇
  1992年   1篇
  1991年   2篇
  1987年   1篇
  1986年   3篇
  1983年   1篇
排序方式: 共有652条查询结果,搜索用时 15 毫秒
71.
In Drosophila melanogaster, p53 (Dmp53) is an important mediator of longevity. Expression of dominant-negative (DN) forms of Dmp53 in adult neurons, but not in muscle or fat body cells, extends lifespan. The lifespan of calorie-restricted flies is not further extended by simultaneously expressing DN-Dmp53 in the nervous system, indicating that a decrease in Dmp53 activity may be a part of the CR lifespan-extending pathway in flies. In this report, we show that selective expression of DN-Dmp53 in only the 14 insulin-producing cells (IPCs) in the brain extends lifespan to the same extent as expression in all neurons and this lifespan extension is not additive with CR. DN-Dmp53-dependent lifespan extension is accompanied by reduction of Drosophila insulin-like peptide 2 (dILP2) mRNA levels and reduced insulin signaling (IIS) in the fat body, which suggests that Dmp53 may affect lifespan by modulating insulin signaling in the fly.  相似文献   
72.
Objective: This study aimed to determine prevalence of latent tuberculosis infection among medical students and tuberculosis exposure at the health facilities. Methods: A cross-section of study year 1(n=68) and year 5(n=75) medical students in a local university were recruited for latent tuberculosis infection testing using QuantiFERON-TB Gold Plus and a questionnaire analyzed for multivariate risk. Results: The majority of the study were vaccinated with BCG. None of year 1 medical students were positive for latent tuberculosis infection, however, six(8.0%) year 5 students were tested positive for latent tuberculosis infection. A higher incidence of year 5 medical students claimed to be exposed to tuberculosis at health facility(65.3% vs. 4.4%) and a higher percentage reported contact with tuberculosis case over the preceding year compared to year 1 students(30.7% vs. 8.8%). Conclusion: We observed a higher incidence of latent tuberculosis infection and higher exposure to tuberculosis in health facilities among year 5 medical students. Baseline screening and monitoring for progression to tuberculosis infection may benefit tuberculosis management programs.  相似文献   
73.

Objective

Advances in childhood cancer treatment have contributed to an increased survival rate among childhood cancer patients. The increasing number of survivors means that more help is needed to support them in dealing with the physical and psychosocial problems following their cancer therapy. This study explored the needs of adolescent cancer survivors in terms of health care and psychosocial services.

Method

This qualitative research used a phenomenological approach. Eight adolescent cancer survivors were interviewed using a semi-structured format. The data were analyzed using a thematic analysis.

Results

Seven themes emerged from the study results: (i) follow-up care; (ii) education for patients and their families; (iii) compassionate health care services; (iv) psychological counseling; (v) support from families and friends; (vi) support from school; and (vii) support from social community activities.

Conclusions

These findings showed that adolescent cancer survivors in Indonesia need long term follow-up care for their physical and psychosocial needs. Nurses should play an active role in addressing the needs of adolescent cancer survivors as described in this study.  相似文献   
74.
This pilot study evaluated the effect sizes associated with prerecorded hypnotic interventions provided during the perisurgical period for reducing risk factors associated with chronic postsurgical pain, including acute postsurgical pain, anxiety, depression, and pain catastrophizing. A total of 25 participants (N = –25) were randomly assigned to receive a hypnotic intervention (n = 8), minimal-effect treatment (n = 8), or treatment as usual (n = 9) during their hospital stay for total knee replacement (TKR). Participants were followed for 6 months after hospital discharge. Results indicate that prerecorded hypnotic intervention exerted medium effects for reducing acute postsurgical pain and large effects for reducing perisurgical anxiety and pain catastrophizing. The findings indicate that a fully powered clinical trial to evaluate the beneficial effects of prerecorded hypnosis to manage pain and psychological distress in patients undergoing TKR is warranted.  相似文献   
75.
AIM: To investigate the risk association of xeroderma pigmentosum group C (XPC ) Lys939Gln polymorphism alone and in combination with cigarette smoking on colorectal cancer (CRC) predisposition. METHODS: Peripheral blood samples of 510 study subjects (255 CRC patients, 255 controls)were collected. DNA was extracted and genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. The association between polymorphic genotype and CRC predisposition was determined using the OR and 95%CI. RESULTS: The frequency of the homozygous variant (Gln/Gln) genotype was significantly higher in cases compared with controls (16.0% vs 10.2%, P = 0.049). The Gln/Gln genotype of XPC showed a significantly higher association with the risk of CRC (OR = 1.884; 95%CI: 1.082-3.277; P = 0.025). In the case of allele frequencies, variant allele C was associated with a significantly increased risk of CRC (OR = 1.375; 95%CI: 1.050-1.802; P = 0.020). Moreover, the risk was markedly higher for those who were carriers of the Gln/Gln variant genotype and were also cigarette smokers (OR = 3.409; 95%CI: 1.061-10.949; P = 0.032). CONCLUSION: The XPC Gln/Gln genotype alone and in combination with smoking increases the risk of CRC among Malaysians.  相似文献   
76.
Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/AlS.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/AlS.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.  相似文献   
77.
AIM: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8 -251T>A polymorphism on colorectal cancer (CRC) susceptibility risk.METHODS: Peripheral blood samples of 255 normal controls and 255 clinically and histopathologically confirmed CRC patients were genotyped for IL-8 -251T>A polymorphism employing allele-specific polymerase chain reaction. The relative association of variant allele and genotypes with CRC susceptibility risk was determined by calculating the odds ratios (ORs). Corresponding χ2 tests on the CRC patients and controls were carried out and 95% confidence intervals (CIs) were determined using Fisher’s exact test. The allele frequencies and its risk association were calculated using FAMHAP, haplotype association analysis software.RESULTS: On comparing the frequencies of genotypes of patients and controls, the homozygous variant AA was significantly higher in CRC patients (P = 0.002) compared to controls. Investigation on the association of the polymorphic genotypes with CRC susceptibility risk, showed that the homozygous variant IL-8 -251AA had a significantly increased risk with OR 3.600 (95% CI: 1.550-8.481, P = 0.001). In the case of allele frequencies, variant allele A of IL-8 -251 showed a significantly increased risk of CRC predisposition with OR 1.32 (95% CI: 1.03-1.69, P = 0.003).CONCLUSION: Variant allele and genotype of IL-8 (-251T>A) was significantly associated with CRC susceptibility risk and could be considered as a high-risk variant for CRC predisposition.  相似文献   
78.
The molecular basis of coronary artery disease (CAD) has been widely studied in the western world but there is no published work on the Malaysian population. This study looked at the global gene expression profiling of the peripheral blood of patients with CAD from the 3 main ethnic groups in Malaysia. Male subjects selected were based on angiographically confirmed CAD (≥50% stenosis) and normal control subjects (0% stenosis) with age range of 55.6±5.3 and 51.0±5.5years, respectively. The global gene expression of 12 angiographically documented CAD patients and 11 matched control subjects were performed. The combined group samples identified 6 up regulated differential expression (DE) genes (GHRL, LTA, CBS, HP, ITGA2B, and OLR1) and 12 down regulated DE genes (IL18R1, ITGA2B, IL18RAP, HP, OLR1, SOD2 ITGB3, IL1B, MMP9, PLA2G7, UTS2, and CBS) to be involved in CAD at the fold change of 1.3 with fault discovery rate (FDR) of 1%. Three genes, MMP9, IL1B, and SOD2 were down regulated in all the 3 ethnic groups making them potential biomarker candidates for CAD across all three ethnicities. Further verification in a cohort study is needed.  相似文献   
79.
Synthesis of zeolite T with a variety of desired characteristics necessitates extensive work in formulation and practical experiments, either by conventional hydrothermal methods or aided with different approaches and synthesis techniques, such as secondary growth or microwave irradiation. The objectives of this review are to adduce the potential work in zeolite T (Offretite-Erionite) synthesis, evaluating determining factors affecting the synthesis and quality of zeolite T crystals. Attention is given to extensive studies that interconnect with other significant findings.  相似文献   
80.
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