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   844篇
  免费   35篇
  国内免费   3篇
耳鼻咽喉   36篇
儿科学   35篇
妇产科学   50篇
基础医学   96篇
口腔科学   9篇
临床医学   69篇
内科学   179篇
皮肤病学   10篇
神经病学   28篇
特种医学   8篇
外科学   66篇
综合类   17篇
一般理论   1篇
预防医学   31篇
眼科学   59篇
药学   90篇
中国医学   2篇
肿瘤学   96篇
  2024年   1篇
  2023年   9篇
  2022年   9篇
  2021年   30篇
  2020年   10篇
  2019年   14篇
  2018年   16篇
  2017年   17篇
  2016年   11篇
  2015年   16篇
  2014年   32篇
  2013年   39篇
  2012年   49篇
  2011年   62篇
  2010年   48篇
  2009年   32篇
  2008年   50篇
  2007年   53篇
  2006年   45篇
  2005年   57篇
  2004年   38篇
  2003年   31篇
  2002年   38篇
  2001年   21篇
  2000年   14篇
  1999年   14篇
  1998年   7篇
  1997年   11篇
  1996年   5篇
  1995年   8篇
  1994年   2篇
  1993年   5篇
  1992年   10篇
  1991年   9篇
  1990年   3篇
  1989年   2篇
  1988年   8篇
  1987年   10篇
  1986年   9篇
  1985年   7篇
  1984年   7篇
  1983年   4篇
  1982年   5篇
  1980年   1篇
  1979年   5篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
排序方式: 共有882条查询结果,搜索用时 15 毫秒
871.
Clozapine was introduced in European market in 1972 as an effective treatment for schizophrenia without extrapyramidal side effects. Within a short while, the clozapine story virtually came to a halt following detection of life-threatening neutropenia and agranulocytosis. Judicial use of granulocyte colony stimulating factor (GCSF) can be life saving with infrequent side effects in these cases. Here we are presenting a case of clozapine induced agranulocytosis managed with GCSF but had transient but life-threatening thrombocytosis, a very uncommon complication of GCSF therapy. Expression of GCSF receptors on the surface of megakaryocytic lineage is thought to be the cause of this unusual phenomenon.  相似文献   
872.
873.
Thrombospondin-1 (TSP-1), a multifunctional matrix glyco-protein, has been shown to control tumor growth by inhibiting angiogenesis in various tissues. However, the role of this glycoprotein in pituitary angiogenesis is not well studied. In this report, we determined the changes in the production and action of TSP-1 on endothelial cells in anterior pituitary following estradiol treatment, which is known to increase prolactin-secreting tumor growth and vascularization in this tissue. We showed that TSP-1 immunoreactive protein is distributed in the anterior pituitary, particularly in the endothelial cells. Estradiol treatment for 2 and 4 weeks decreased the total tissue immunoreactive level of TSP-1 as well as the endothelial cell-specific immunoreactive level of this protein in the anterior pituitary. The steroid treatment also decreased the protein levels of TSP-1 in anterior pituitary tissues and in purified pituitary endothelial cells in primary cultures. Determination of the effects of TSP-1 on proliferation and migration of pituitary-derived endothelial cells in primary cultures elucidated an inhibitory action of TSP-1 on these vascular cell functions. These results suggest that locally produced TSP-1 may regulate estrogen angiogenic action on the pituitary.  相似文献   
874.
INTRODUCTION: Low vitamin D status is prevalent among South Asians living in the UK. The relationship, however, between serum 25-hydroxyvitamin D level (25OHD), serum parathyroid level (PTH) and bone mass in this group of women is unknown. The aim of this study was to determine the association between serum PTH, 25OHD and bone mass in a population based sample of young UK South Asian women. MATERIALS AND METHODS: Names of South Asian women aged 18 to 36 years of Pakistani origin living in the Greater Manchester area were identified from primary care registers using validated computer software. Subjects were invited to attend for (i) a blood test for assessment of serum calcium (Ca), albumin, PTH and 25OHD and (ii) for bone mineral density (BMD) scanning using the following: areal BMD at the hip (femoral neck, total hip) and lumbar spine using dual X-ray absorptiometry (Hologic QDR 4500), and volumetric BMD at the distal radius using peripheral quantitative computed tomography (Norland Stratec XCT 2000). Linear regression was used to determine the association between serum 25OHD, PTH and BMD at the different sites with adjustments made for age. RESULTS: In all, 78 women (mean age 29.2 years) were included in the analysis. Mean serum Ca level was 2.42 mmol/l, 25OHD, 7.9 ng/ml and PTH, 52.8 pg/ml. The majority of women (94%) had serum 25OHD levels 15 ng/ml, though rose progressively in subjects with levels below 10 ng/ml. Serum 25OHD was positively associated with BMD at the hip and spine while PTH was negatively associated with BMD at the hip and spine. When categorized by serum 25OHD level there was an increase in BMD at the total hip and distal radial site at least up to levels of 15 ng/ml. CONCLUSIONS: Despite widespread recognition, hypovitaminosis D is still prevalent among young UK South Asian women. In these women a decrease in serum 25OHD level 相似文献   
875.
Although bone metastasis to the acetabulum can cause significant disability from pain and immobility, little has been written about the diagnosis and management of a pathologic acetabular fracture. We present three patients with metastatic acetabular fractures and discuss an approach to evaluation and management. When a high index of suspicion of fracture exists, further radiographic workup is warranted. Management requires a multidisciplinary approach. Factors such as age, associated comorbidities, natural history of the underlying primary cancer, general health status, prognosis, acetabular fracture characteristics, and quality of bone should be considered. We briefly discuss the options available to nonoperative candidates.  相似文献   
876.
877.
878.
879.

Background

Ursolic acid is a powerful drug that possesses many therapeutic properties, such as hepatoprotection, immunomodulation, anti-inflammatory, antidiabetic, antibacterial, antiviral, antiulcer, and anticancer activity. Centella asiatica (L.) Urban (Umbelliferae) contains a triterpene called asiatic acid, which has been used effectively in traditional Chinese and Indian medicine system for centuries. Anticancer, anti-inflammatory, and neuroprotective properties are only some of the many pharmacological actions previously attributed to asiatic acid .

Aim

The present work developed an optimized combinatorial drug-loaded nano-formulation by Quality by design approach.

Materials and Methods

The optimize transliposome for accentuated dermal delivery of dual drug. The optimization of drug-loaded transliposome was done using the “Box–Behnken design.” The optimized formulation was characterized for vesicles size, entrapment efficiency (%), and in vitro drug release. Additionally, transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), and dermatokinetic study were performed for further evaluation of drug-loaded optimized transliposome formulation.

Results

The optimized combinatorial drug-loaded transliposome formulation showed a particle size of 86.36 ± 2.54 nm, polydispersity index (PDI) 0.230 ± 0.008, and an entrapment efficiency of 87.43 ± 2.66% which depicted good entrapment efficiency. In vitro drug release of ursolic acid and asiatic acid transliposomes was found to be 85.12 ± 2.54% and 80.23 ± 3.23%, respectively, as compared to optimized ursolic acid and asiatic acid transliposome gel drug release that was 67.18 ± 2.85% and 60.28 ± 4.12%, respectively. The skin permeation study of ursolic and asiatic acid conventional formulation was only 32.48 ± 2.42%, compared with optimized combinatorial drug-loaded transliposome gel (79.83 ± 4.52%) at 12 h. After applying combinatorial drug-loaded transliposome gel, rhodamine was able to more easily cross rat skin, as observed by confocal laser scanning microscopy, in comparison with when the rhodamine control solution was used.

Discussion

The UA_AA-TL gel formulation absorbed more ursolic acid and asiatic acid than the UA_AA-CF gel formulation, as per dermatokinetic study. Even after being incorporated into transliposome vesicles, the antioxidant effects of ursolic and asiatic acid were still detectable. In most cases, transliposomes vesicular systems generate depots in the skin's deeper layers and gradually release the medicine over time, allowing for fewer applications.

Conclusion

In overall our studies, it may be concluded that developed dual drug-loaded transliposomal formulation has great potential for effective topical drug delivery for skin cancer.  相似文献   
880.
The minor allele of rs373863828, a missense variant in CREB3 Regulatory Factor, is associated with several cardiometabolic phenotypes in Polynesian peoples. To better understand the variant, we tested the association of rs373863828 with a panel of correlated phenotypes (body mass index [BMI], weight, height, HDL cholesterol, triglycerides, and total cholesterol) using multivariate Bayesian association and network analyses in a Samoa cohort (n = 1632), Aotearoa New Zealand cohort (n = 1419), and combined cohort (n = 2976). An expanded set of phenotypes (adding estimated fat and fat-free mass, abdominal circumference, hip circumference, and abdominal-hip ratio) was tested in the Samoa cohort (n = 1496). In the Samoa cohort, we observed significant associations (log10 Bayes Factor [BF] ≥ 5.0) between rs373863828 and the overall phenotype panel (8.81), weight (8.30), and BMI (6.42). In the Aotearoa New Zealand cohort, we observed suggestive associations (1.5 < log10BF < 5) between rs373863828 and the overall phenotype panel (4.60), weight (3.27), and BMI (1.80). In the combined cohort, we observed concordant signals with larger log10BFs. In the Samoa-specific expanded phenotype analyses, we also observed significant associations between rs373863828 and fat mass (5.65), abdominal circumference (5.34), and hip circumference (5.09). Bayesian networks provided evidence for a direct association of rs373863828 with weight and indirect associations with height and BMI.  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