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   2312篇
  免费   138篇
  国内免费   13篇
耳鼻咽喉   12篇
儿科学   110篇
妇产科学   26篇
基础医学   216篇
口腔科学   65篇
临床医学   228篇
内科学   435篇
皮肤病学   25篇
神经病学   87篇
特种医学   186篇
外科学   351篇
综合类   62篇
预防医学   89篇
眼科学   310篇
药学   155篇
中国医学   16篇
肿瘤学   90篇
  2023年   20篇
  2022年   71篇
  2021年   82篇
  2020年   48篇
  2019年   61篇
  2018年   87篇
  2017年   56篇
  2016年   84篇
  2015年   77篇
  2014年   110篇
  2013年   106篇
  2012年   172篇
  2011年   199篇
  2010年   115篇
  2009年   93篇
  2008年   178篇
  2007年   173篇
  2006年   127篇
  2005年   119篇
  2004年   95篇
  2003年   80篇
  2002年   62篇
  2001年   23篇
  2000年   24篇
  1999年   30篇
  1998年   7篇
  1997年   6篇
  1996年   7篇
  1995年   11篇
  1994年   9篇
  1993年   6篇
  1992年   10篇
  1991年   12篇
  1990年   14篇
  1989年   9篇
  1988年   20篇
  1987年   9篇
  1986年   7篇
  1985年   10篇
  1984年   7篇
  1983年   5篇
  1980年   2篇
  1978年   2篇
  1973年   4篇
  1970年   1篇
  1969年   2篇
  1967年   1篇
  1966年   1篇
  1965年   1篇
  1962年   1篇
排序方式: 共有2463条查询结果,搜索用时 15 毫秒
91.
Mild cognitive impairment (MCI) is associated with an increased risk of developing dementia. This is clinically relevant overt dementia can be prevented if treatment strategies are devised for MCI. Neuropsychological deficits in this condition are very common and are important clinically for treatment and outcomes. We aimed to review various neuropsychological deficits in MCI. Further, we have presented the current evidence for nosological status, neuroanatomical basis, and clinical outcome of this heterogeneous construct. All published papers on the topic of neuropsychological deficits in MCI on Medline and other databases were reviewed. A wide range of memory and executive function deficits are common in MCI patients. However, several studies are limited by either improper designs or inadequate sample sizes. Several neuropsychological impairments like memory function and executive functions can be diagnosed in MCI. The evidence base for the exact neuroanatomical basis of MCI is not robust yet. However, given the wide range of outcomes, controversies and debates exist regarding the nosological significance of the deficits. Hence, more studies are needed to specifically locate the impairments and further delineate the construct of MCI.  相似文献   
92.
93.

Aim

To determine the need to screen postpartum women for postpartum depression.

Objective

This study was designed to determine the prevalence of an Edinburgh postnatal depression scale (EPDS) score of ≥13 in postpartum mothers and to evaluate the association of different sociodemographic and obstetric factors with postpartum depression.

Design

Prospective cohort study.

Method

1600 postpartum women who delivered a live born at St. John’s Hospital were recruited into the study. Participants were screened for postnatal depression using the EPDS. A risk factor questionnaire that covered key sociodemographic and obstetric factors was also completed by all the subjects. Main Outcome Measure: Prevalence of a score of 13 or higher, on the EPDS.

Results

The prevalence of an EPDS score of ≥13 in our population was 7.5 % (120/1600). Participants with a family history of psychiatric illness, history of domestic abuse, delayed initiation of breastfeeding, and those who gave birth to a female infant were at a significantly higher risk for an EPDS score of 13 or higher, indicating probable postnatal depression. The mode of delivery, NICU admission of the newborn, and history of antenatal complications were not significant risk factors.

Conclusion

Since the prevalence of an EPDS score ≥13 (which is suggestive of PPD) was found in a significant proportion of women, screening for PPD is indicated in all postpartum women to identify and promptly treat these women. Identification of a clear correlation between certain risk factors and PPD will lead to a more prompt diagnosis of PPD.
  相似文献   
94.
95.

Background

It has been suggested that the anterolateral ligament (ALL) of the knee may have importance in limiting rotational instability, and reconstruction may prevent a continued pivot-shift following anterior cruciate ligament surgery. However, the anatomy of this ligament has not been consistently reported in recent publications. We describe our experience of cadaveric dissection with reference to other published work.

Materials and Methods

Eleven fresh-frozen cadaveric knees were dissected using a standard technique. The ALL tissue was identified with internal rotation of the tibia and varus stress. Measurements were made using a digital caliper and details of the origin and insertion were recorded.

Results

The ALL was identified in ten of the 11 cadavers. The only specimen in which it was not identified was found to also have an anterior cruciate ligament deficiency. The mean dimensions were: length 40.1 (± 5.53) mm, width 4.63 (± 1.39) mm, thickness 0.87 (± 0.18) mm. The femoral origin was posterior and proximal to the lateral collateral ligament attachment in six knees, anterior and distal in three knees, and at the same site in one knee. The tibial insertion was a mean 17.7 (± 2.95) mm from Gerdy’s tubercle (GT) and 12.3 (± 3.55) mm from the fibula head (FH). This was 59.5 (± 5.44) % from GT to FH.

Conclusions

This anatomical data adds to previous information about the ALL. Our results support the finding that the ALL is a capsular thickening with meniscal attachment. The findings will help to guide the further work required to define the indications for reconstruction and appropriate grafts.
  相似文献   
96.
A major factor in non-allergic food hypersensitivity could be the interaction of dietary lectins with mast cells and basophils. Because immunoglobulin E (IgE) contains 10-12% carbohydrates, lectins can activate and degranulate these cells by cross-linking the glycans of cell-bound IgE. The present objective focuses on the effect of potato lectin (Solanum tuberosum agglutinin; STA) for its ability to release histamine from basophils in vitro and mast cells in vivo from non-atopic and atopic subjects. In this study, subjects were selected randomly based on case history and skin prick test responses with food, pollen and house dust mite extracts. Skin prick test (SPT) was performed with STA at 100 microg/ml concentration. Histamine release was performed using leucocytes from non-atopic and atopic subjects and rat peritoneal exudate cells. SPT on 110 atopic subjects using STA showed 39 subjects positive (35%); however, none showed STA-specific IgE; among 20 non-atopic subjects, none were positive by SPT. Maximal histamine release was found to be 65% in atopic subjects (n = 7) compared to 28% in non-atopic subjects (n = 5); the release was inhibited specifically by oligomers of N-acetylglucosamine and correlates well with serum total IgE levels (R(2) = 0.923). Binding of STA to N-linked glycoproteins (horseradish peroxidase, avidin and IgG) was positive by dot blot and binding assay. As potato lectin activates and degranulates both mast cells and basophils by interacting with the chitobiose core of IgE glycans, higher intake of potato may increase the clinical symptoms as a result of non-allergic food hypersensitivity in atopic subjects.  相似文献   
97.
1.?In vitro studies were conducted to evaluate potential inhibitory and inductive effects of the poly(ADP-ribose) polymerase (PARP) inhibitor, olaparib, on cytochrome P450 (CYP) enzymes. Inhibitory effects were determined in human liver microsomes (HLM); inductive effects were evaluated in cultured human hepatocytes.

2.?Olaparib did not inhibit CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2D6 or CYP2E1 and caused slight inhibition of CYP2C9, CYP2C19 and CYP3A4/5 in HLM up to a concentration of 100?μM. However, olaparib (17–500?μM) inhibited CYP3A4/5 with an IC50 of 119?μM. In time-dependent CYP inhibition assays, olaparib (10?μM) had no effect against CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP2E1 and a minor effect against CYP3A4/5. In a further study, olaparib (2–200?μM) functioned as a time-dependent inhibitor of CYP3A4/5 (KI, 72.2?μM and Kinact, 0.0675?min?1). Assessment of the CYP induction potential of olaparib (0.061–44?μM) showed minor concentration-related increases in CYP1A2 and more marked increases in CYP2B6 and CYP3A4 mRNA, compared with positive control activity; however, no significant change in CYP3A4/5 enzyme activity was observed.

3.?Clinically significant drug–drug interactions due to olaparib inhibition or induction of hepatic or intestinal CYP3A4/5 cannot be excluded. It is recommended that olaparib is given with caution with narrow therapeutic range or sensitive CYP3A substrates, and that prescribers are aware that olaparib may reduce exposure to substrates of CYP2B6.  相似文献   
98.
99.
The aim of this study was to describe a novel device that has been designed to facilitate anterior segment and novice surgeons to perform extraocular needle-guided haptic insertion technique (X-NIT) for scleral fixation intraocular lens surgery (SFIOL). We performed SFIOL surgery using X-NIT device in 21 eyes of 21 patients. The mean preoperative best-corrected visual acuity (BCVA) was 0.5 ± 0.2 logarithm of minimum angle of resolution (log MAR), which improved by one or more lines postoperatively in all eyes. There were no intraoperative complications. Postoperatively, we noted minimal corneal edema in one patient and dispersed vitreous hemorrhage in one patient. The sharpness and angulation of the needle and the haptic holding ability of silicone stopper were found to be satisfactory. The X-NIT device may potentially improve the safety of SFIOL procedures by minimizing intraocular maneuvers.  相似文献   
100.
Purpose:To identify factors affecting family members'' decision whether to donate eye organs.Methods:A community-based case-control study based on in-home interviews with families of deceased individuals who had or had not donated eye organs, in Madurai district, Tamil Nadu, India. Data collected were knowledge and awareness of eye donations, whether the deceased individual had expressed or pledged willingness to donate, and family members'' attitudes and willingness to donate their own eye organs.Results:Seventy-six families of donors and 256 families of non-donors completed the survey. Multivariable analysis showed that the following variables were significantly associated with a donation: age, whether the deceased had registered for eye donation, pre-expressed willingness of deceased to donate, whether family members personally know beneficiaries of eye donations, and higher score on a scale evaluating knowledge and awareness about eye donation. The majority of donors'' families (71%) had been encouraged by someone to donate. Among non-donor families, a substantially larger fraction (52.8%) indicated they would have donated had someone reminded or encouraged them to do so, in comparison with those who indicated lack of awareness or knowledge (14.5%).Conclusion:Community programs are likely to be effective if they encourage individuals to pledge their eyes or express their willingness to donate their eyes to family members in advance of death; they increase public awareness of the value of eye donation. A friend, family member, neighbor or counselor approaching bereaved families and having a dialogue about eye donation would substantially increase the probability of a decision to donate.  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