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   2441篇
  免费   139篇
  国内免费   9篇
耳鼻咽喉   6篇
儿科学   133篇
妇产科学   72篇
基础医学   274篇
口腔科学   33篇
临床医学   173篇
内科学   473篇
皮肤病学   46篇
神经病学   111篇
特种医学   67篇
外科学   450篇
综合类   56篇
预防医学   104篇
眼科学   158篇
药学   202篇
中国医学   18篇
肿瘤学   213篇
  2023年   11篇
  2022年   35篇
  2021年   90篇
  2020年   50篇
  2019年   69篇
  2018年   98篇
  2017年   57篇
  2016年   84篇
  2015年   74篇
  2014年   113篇
  2013年   144篇
  2012年   180篇
  2011年   207篇
  2010年   102篇
  2009年   108篇
  2008年   164篇
  2007年   169篇
  2006年   153篇
  2005年   130篇
  2004年   112篇
  2003年   98篇
  2002年   66篇
  2001年   30篇
  2000年   24篇
  1999年   27篇
  1998年   13篇
  1997年   13篇
  1996年   14篇
  1995年   5篇
  1994年   13篇
  1993年   7篇
  1992年   11篇
  1991年   11篇
  1990年   6篇
  1989年   10篇
  1988年   7篇
  1987年   7篇
  1986年   5篇
  1985年   3篇
  1984年   5篇
  1981年   5篇
  1972年   2篇
  1971年   2篇
  1970年   4篇
  1969年   2篇
  1967年   2篇
  1966年   4篇
  1961年   9篇
  1934年   6篇
  1930年   3篇
排序方式: 共有2589条查询结果,搜索用时 15 毫秒
41.

Introduction

This study was conducted to evaluate and compare maturogenesis induced by revascularization with and without platelet-rich plasma (PRP).

Methods

Twenty patients with nonvital, immature anterior teeth were randomly categorized into 2 groups. Subsequent to chemomechanical preparation, revascularization with and without PRP carried on a collagen sponge was induced in groups 1 and 2, respectively. The cases were followed up clinically and radiographically at 6- and 12-month intervals.

Results

Clinically, all cases were asymptomatic with complete resolution of signs and symptoms. Radiographically, there was a marked difference in periapical healing, apical closure, and dentinal wall thickening in group 2 in comparison with group 1. However, root lengthening was comparable for both of the procedures.

Conclusions

Revascularization is a conservative and an effective method for inducing maturogenesis in nonvital, immature teeth. Supplementations with PRP can potentially improve the desired biological outcome of this regenerative technique.  相似文献   
42.

Introduction

Pelvic Organ Prolapse Quantification (POP-Q) system, measured in centimetres using a ruler (e.g. POPstix®), is recommended to quantify prolapse severity. POPstix® are costly (US $1/ruler). Home-made devices are used instead, but these have not been shown to be reproducible.

Hypothesis

Digitally assessed POP-Q (DPOP-Q) is as reliable, reproducible and acceptable as POP-Q assessed using POPstix®.

Methods

In this randomised crossover diagnostic agreement trial, each assessor measured the index finger of their dominant hand using a ruler. At visit one, patients were randomised to either POPstix® POP-Q assessment in a modified lithotomy position or DPOP-Q in both modified a lithotomy and a standing position. After the first clinician conducted this assessment, a second blinded clinician then carried out the remaining assessment on the same patient. For each examination, duration was recorded, along with a patient-completed discomfort score. Twenty-five women were invited for visit two, at which DPOP-Q was recorded by the same clinician who undertook DPOP-Q at the first visit. This allowed evaluation of inter- and intraobserver agreement together with examination acceptability.

Results

One hundred and nine women were recruited [median age 55 years, parity 2, body mass index (BMI) 27.1]. Of the 25 patients invited, 23 returned for visit two. DPOP-Q had high interobserver reliability [κ?=?0.94, 95 % confidence interval (CI) 0.878–0.996] and intraobserver reliability (α?=?0.96) with POPstix®. DPOP-Q was significantly quicker (p?=?0.02) and less uncomfortable (p?<?0.01) than POPstix® POP-Q.

Conclusion

DPOP-Q is reliable, acceptable and cost effective.
  相似文献   
43.
44.
Strains of Enterococcus faecium express a cell wall-anchored protein, Acm, which mediates adherence to collagen. Here, we (i) identify the minimal and high-affinity binding subsegments of Acm and (ii) show that anti-Acm immunoglobulin Gs (IgGs) purified against these subsegments reduced E. faecium TX2535 strain collagen adherence up to 73 and 50%, respectively, significantly more than the total IgGs against the full-length Acm A domain (28%) (P < 0.0001). Blocking Acm adherence with functional subsegment-specific antibodies raises the possibility of their use as therapeutic or prophylactic agents.  相似文献   
45.
Cancer of breast and cervix reign supreme among the fatal diseases in women globally. Interestingly the ovarian cancer has the highest mortality rate. This is attributed to its late clinical presentation and delayed diagnosis. The expression of p53 throws light on the prognosis of ovarian tumors. The surface epithelial tumors, especially the serous cystadenocarcinoma and non Hodgkin lymphoma of ovary where in the expression p53 was high compared to the benign and borderline tumors. Further the expression of p53 in tumors arising from germinal cells, sex-cord stromal cells are observed to be very low. The expression of p53 and its correlation to the morphology enhances the prognostic significance.  相似文献   
46.
A 24-year-old female underwent small incision lenticule extraction (SMILE) for myopic astigmatism OU. In the left eye, cap-lenticular adhesion along with tearing of the cap occurred, resulting in a gaped incision and transverse striae involving the visual axis on the first post op day. Uncorrected distance visual acuity (UDVA) was 20/32. The case was managed with interface wash and stretching of the cap, in order to iron out the striae. Post intervention, the UDVA improved to 20/20, striae resolved, and interface remained clear through a follow-up of nine months, suggesting that cap striae in SMILE may be similarly managed as the flap striae in laser-assisted in situ keratomileusis (LASIK), resulting in satisfactory visual outcomes.  相似文献   
47.
A library of 2,5-disubstituted 1,3,4-oxadiazole derivatives of (E)-2-aryl-5-(3,4,5-trimethoxystyryl)-1,3,4-oxadiazoles 4(ao) and (E)-2-aryl-5-(2-benzo[d][1,3]dioxol-5-yl)vinyl)-1,3,4-oxadiazoles 5(aq) were synthesized and evaluated for their in vitro acetylcholinesterase (AChE) inhibitory activity. All the synthesized compounds exhibited moderate to good inhibitory activity toward the AChE enzyme. Among the oxadiazole derivatives examined, compounds 4a, 4g, 5c, and 5m (IC50 values of 24.89, 13.72, 37.65, and 19.63 μM, respectively) were found to be promising inhibitors of AChE. Molecular protein–ligand docking studies were examined for these compounds using GOLD docking software and their binding conformations were determined and the simultaneous interactions mode was also established for the potent derivatives.  相似文献   
48.
49.
Kudva GC  Maliekel K  Kim HJ  Naunheim KS  Stolar C  Fletcher JW  Puri S 《Chest》2002,121(6):2061-2063
We present the case of a 42-year-old woman with myotonic dystrophy and thymoma. She was treated with combination chemotherapy followed by external beam radiation, and remains in remission 19 months after thymoma was diagnosed. The myotonic dystrophy is unchanged. Only six cases of this nature have been reported in the literature, and this patient is the first to be successfully treated with combined modality therapy.  相似文献   
50.
Although heparin and low-molecular-weight heparins (LMWH) have been widely used clinically as anticoagulants, their broader use has been limited by the lack of noninvasive delivery methods for this class of molecules. In this study, we demonstrate an efficient, rapid, and reproducible delivery system for heparin through the lungs that is not confined to particles of a certain geometric or aerodynamic diameter. Importantly, blood levels after intrapulmonary administration of either heparin or LMWH were comparable to that of s.c. administration but are characterized by a more rapid onset of action (t(1/2) = 40 min vs. 2.5 h, respectively). Furthermore, we show in animal models, that inhaled heparin species efficiently inhibit diseases such as thrombosis and emphysema, and that the repetitive inhalation of formulated LMWH results in no observable toxicity from the delivery of reproducible systemic levels of heparin or LMWH.  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