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   7753篇
  免费   717篇
  国内免费   38篇
耳鼻咽喉   95篇
儿科学   211篇
妇产科学   164篇
基础医学   928篇
口腔科学   563篇
临床医学   975篇
内科学   1612篇
皮肤病学   192篇
神经病学   736篇
特种医学   201篇
外科学   999篇
综合类   39篇
一般理论   1篇
预防医学   665篇
眼科学   180篇
药学   599篇
中国医学   54篇
肿瘤学   294篇
  2023年   114篇
  2022年   180篇
  2021年   301篇
  2020年   220篇
  2019年   238篇
  2018年   328篇
  2017年   257篇
  2016年   295篇
  2015年   351篇
  2014年   431篇
  2013年   485篇
  2012年   550篇
  2011年   640篇
  2010年   360篇
  2009年   316篇
  2008年   394篇
  2007年   435篇
  2006年   349篇
  2005年   340篇
  2004年   253篇
  2003年   202篇
  2002年   182篇
  2001年   141篇
  2000年   129篇
  1999年   117篇
  1998年   72篇
  1997年   52篇
  1996年   56篇
  1995年   42篇
  1994年   27篇
  1993年   14篇
  1992年   65篇
  1991年   75篇
  1990年   39篇
  1989年   52篇
  1988年   48篇
  1987年   33篇
  1986年   37篇
  1985年   32篇
  1984年   24篇
  1983年   14篇
  1982年   11篇
  1981年   13篇
  1980年   21篇
  1979年   23篇
  1978年   21篇
  1977年   16篇
  1976年   12篇
  1975年   13篇
  1974年   16篇
排序方式: 共有8508条查询结果,搜索用时 15 毫秒
51.
Although hydrogel extended-wear contact lenses (EWCLs) have been used extensively in the correction of aphakia in neonates, little is known about the effects of these lenses on infant corneas. Recent studies have demonstrated that long-term contact lenses can induce endothelial morphometric changes, including an increased coefficient of variation (CV) of mean endothelial cell area. Using wide-field specular microscopy, the authors studied 11 eyes of 10 patients, 1 to 3 years of age who, after lensectomy for congenital cataracts, wore EWCLs for the correction of aphakia. Except for two corneas in which increased pachometric readings and CV developed after repeated episodes of lens loss and inflammation, the EWCL were well tolerated and associated with few complications in this study.  相似文献   
52.
OBJECTIVE: The objective was to analyze the effect of raloxifene on the vaginal epithelium of postmenopausal women. STUDY DESIGN: In this non-randomized clinical trial, 80 women (mean age = 60.6 years) were prospectively studied. Forty patients received 60 mg/day of raloxifene (RG), and 40 women constituted a non-treated control group (CG), paired by age and time since menopause. The treated group consisted of patients with osteoporosis of the lumbar spine. Those with a diagnosis of infection in the lower genital tract and using hormone therapy (HT) up to 6 months prior to the study were excluded. Vaginal smears were collected at baseline and after 6 months of intervention. The vaginal maturation value (VMV) was determined, and counts of superficial, intermediate and parabasal cells were performed. Smears were analyzed by only one cytopathologist who was blinded to patient data. The t-test, Wilcoxon test, and Chi-Squared test were used in the statistical analysis. RESULTS: The study groups were homogeneous regarding age, time since menopause, parity, HT use, smoking, and body mass index. No statistically significant differences were observed in VMV median values (RG, 39.7 and 35.7; CG, 50.0 and 50.0, respectively) or in the percentage of superficial, intermediate and parabasal cells between the groups at baseline and after 6 months (p>0.05). There was no significant correlation between VMV and age, time since menopause, previous HT use, or body mass index, in either of the groups. CONCLUSION: Treatment with raloxifene for 6 months has no effect on the maturation of the vaginal epithelium in postmenopausal women with osteoporosis.  相似文献   
53.
OBJECTIVE: The aim of the present study was to compare the distribution of G1691A, G20210A and C677T mutations in pre-eclamptic Brazilian women and in matched control women with an uncomplicated normal pregnancy. STUDY DESIGN: these mutations were investigated by PCR-RFLP in 83 normal pregnancies (control group) and in 30 pre-eclamptic pregnant women (severe form). RESULTS: G1691A mutation was detected neither in the control group nor in pre-eclamsia women. G20210A mutation was detected in heterozygosis in 3 (3.61%) control subjects, but not in pre-eclampsia group. C677T mutation was detected in homozygosis in 6 (7.23%) control subjects and 2 (6.67%) pre-eclamptic women and in heterozygosis in 31 (37.3%) control subjects and 12 (40%) pre-eclamptic women. Differences in the mutation frequencies detected in the two groups were not statistically significant. CONCLUSION: No correlation was observed between pre-eclampsia and presence of G1691A, G20210A and C677T mutations in Brazilian women.  相似文献   
54.
Prostate cancer remains one of the leading causes of cancer death in men worldwide. In the past decade, several new treatments for advanced prostate cancer have been approved. With a wide variety of available drugs, including cytotoxic agents, androgen receptor axis-targeted therapies, and alpha-emitting radiation therapy, identifying their optimal sequencing remains a challenge. Progress in the understanding of the biology of prostate cancer has provided an opportunity for a more refined and personalized treatment selection process. With the advancement of molecular sequencing techniques, genomic precision through the identification of potential treatment targets and predictive biomarkers has been rapidly evolving. In this review, we discussed biomarker-driven treatments for advanced prostate cancer. First, we presented predictive biomarkers for established, global standard treatments for advanced diseases, such as chemotherapy and androgen receptor axis-targeted agents. We also discussed targeted agents with recent approval for special populations, such as poly ADP ribose polymerase (PARP) inhibitors in patients with metastatic castrate-resistant prostate cancer with homologous recombination repair-deficient tumors, pembrolizumab in patients with high levels of microsatellite instability or high tumor mutational burden, and prostate-specific membrane antigen (PSMA) directed radioligand theragnostic treatment for PSMA expressing tumors. Additionally, we discussed evolving treatments, such as cancer vaccines, chimeric antigen receptor T-cells (CAR-T), Bispecific T-cell engagers (BiTEs), other targeted agents such as AKT inhibitors, and various combination treatments. In summary, advances in molecular genetics have begun to propel personalized medicine forward in the management of advanced prostate cancer, allowing for a more precise, biomarker-driven treatment selection with the goal of improving overall efficacy.  相似文献   
55.
Purpose of ReviewThis paper presents some approaches and techniques for translating an idea or research into clinical practice, considering the innovation development process.Recent FindingsInnovative tools have been a key solution for healthcare problems, such as musculoskeletal disorders, which represent a great economic burden and are among the leading causes of disability. There has been an increase in publications on this topic, but there has been no analysis of the process of innovation development. This review describes the innovation phases for translating an idea or research into clinical practice, considering the stages of discovering the opportunity, innovation creation, project specification, technology development, and innovation launch.SummaryAn analysis of the innovation development process to translate an idea or research into clinical practice, including concepts, approaches, and techniques that shows the “why”, “how”, and “what” of innovation.  相似文献   
56.
Hepatobiliary surgery is a challenging surgical subspecialty that requires highly specialized training and an adequate level of experience in order to be performed safely. As a result, minimally invasive hepatobiliary surgery has been met with slower acceptance as compared to other subspecialties, with many surgeons in the field still reluctant about the approach. On the other hand, gastric surgery is a very popular field of surgery with an extensive amount of literature especially regarding open and laparoscopic surgery but not much about the robotic approach especially for oncological disease. Recent development of the robotic platform has provided a tool able to overcome many of the limitations of conventional laparoscopic hepatobiliary surgery. Augmented dexterity enabled by the endowristed movements, software filtration of the surgeon’s movements, and high-definition three-dimensional vision provided by the stereoscopic camera, allow for steady and careful dissection of the liver hilum structures, as well as prompt and precise endosuturing in cases of intraoperative bleeding. These advantages have fostered many centers to widen the indications for minimally invasive hepatobiliary and gastric surgery, with encouraging initial results. As one of the surgical groups that has performed the largest number of robot-assisted procedures worldwide, we provide a review of the state of the art in minimally invasive robot-assisted hepatobiliary and gastric surgery. The English full-text version of this article is available at SpringerLink (under supplemental).  相似文献   
57.
End-stage renal disease (ESRD) under hemodialyses (HD) is related with a higher propensity to infections, essentially due to T-cell lymphopenia. We postulated that HD procedure affects CD4(+) T cells, especially by inducing apoptotic death and that recombinant human erythropoietin (rhEPO) therapy may also play an important role in the modulation of the immune system in these patients. T-cell phenotype and apoptosis of HD patients and healthy controls were evaluated by flow cytometry using anticoagulated whole-blood samples. In 12 HD patients, these parameters were also analyzed before and immediately after HD procedure. HD patients showed a decrease in total circulating CD3(+) lymphocytes, especially in CD4(+) T cells (0.747 ± 0.410 vs. 0.941 ± 0.216 × 10(9)/L, p < 0.05), which could be a consequence of the higher proportion of CD3(+) and CD4(+) lymphocytes in the latest stage of apoptosis (or death) and of the higher proportion of apoptotic CD4(+) T cells observed in the patients immediately after HD procedure (2.91 ± 0.780 vs. 3.90 ± 1.96, p < 0.05). A positive and statistically significant correlation between CD3(+) and CD4(+) lymphocytes in latest stage of apoptosis (or death) with HD time was found (CD3(+): r = 0.592, p < 0.01; CD4(+): r = 0.501, p < 0.01). We also found a negative and significant correlation between weekly rhEPO doses and the number of CD4(+) T cells (r = -0.358, p < 0.05). In conclusion, HD procedure still contributes to the development of T-cell lymphopenia, at least in part, by apoptosis induction. It was also shown that rhEPO therapy is associated with the CD4(+) T-cell decline, possibly by immune modulation, eliminating atypical cells and helping to restore the CD4(+) T-cell subset.  相似文献   
58.
59.
60.
This study aimed to evaluate the prevalence of sexually transmitted infections (STIs) and associated risk factors in HIV-infected pregnant women followed for prenatal care in Salvador, Bahia. This was a cross-sectional study of 63 women seeking prenatal care at a reference center. Participants were interviewed regarding socio-epidemiological and clinical history, and were tested for HBsAg, anti-HCV, anti HTLV I/II, VDRL, Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma hominis, Ureaplasma urealyticum, CD4 count, and HIV plasma viral load. The main outcome variable was the presence of any STI. The mean age of patients was 28.2 years (16-40 years). 23 (36.5%) were diagnosed with at least one STI. The frequency of diagnoses was: HBV, 3.2%; HCV, 8.1%; HTLV I/II, 3.4%; syphilis, 9.5%; Chlamydia trachomatis, 11.1%; HPV, 15.0%; Mycoplasma hominis, 2.1%, and Ureaplasma urealyticum, 2.1%. No case of Neisseria gonorrhoeae was identified. No association was found between socio-epidemiological variables and the presence of an STI. CD4 T lymphocyte < 500 cells/μL (p = 0.047) and plasma viral load >1,000 copies (p = 0.027) were associated with the presence of STI. STIs are frequent in pregnant women infected with HIV, and all HIV-infected pregnant women should be screened to decrease transmission of these pathogens and to protect their own health.  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