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   313篇
  免费   29篇
耳鼻咽喉   6篇
儿科学   7篇
妇产科学   7篇
基础医学   30篇
口腔科学   12篇
临床医学   35篇
内科学   53篇
皮肤病学   28篇
神经病学   28篇
特种医学   8篇
外科学   26篇
综合类   6篇
预防医学   20篇
眼科学   32篇
药学   26篇
中国医学   6篇
肿瘤学   12篇
  2024年   1篇
  2023年   5篇
  2022年   21篇
  2021年   23篇
  2020年   7篇
  2019年   11篇
  2018年   18篇
  2017年   14篇
  2016年   10篇
  2015年   11篇
  2014年   18篇
  2013年   23篇
  2012年   32篇
  2011年   29篇
  2010年   17篇
  2009年   9篇
  2008年   14篇
  2007年   8篇
  2006年   19篇
  2005年   14篇
  2004年   6篇
  2003年   11篇
  2002年   5篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1973年   2篇
排序方式: 共有342条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
BackgroundHypertriglyceridemia induced acute pancreatitis (HIAP) is the third common cause of acute pancreatitis. HIAP can result in recurrent attacks of severe AP with significant morbidity and mortality. Hypertriglyceridemia (HTG) could be primary or secondary. Although genetic causes of HTG are well studied, the prevalence of secondary causes of HTG in patients presenting with HIAP is not well characterized. This study aimed to identify the prevalence of risk factors for secondary hypertriglyceridemia among patients presenting with HIAP in a tertiary referral center in a large metropolitan area.MethodsThis is a retrospective analysis of all patients admitted with AP from August 2012–2017. A subgroup of patients with triglycerides >880 mg/dl were included for analysis. Secondary causes of HTG were identified. Secondary analysis evaluating the severity of pancreatitis was performed.ResultsThere were 3,746 patients admitted for AP of which 57 patients had AP and HTG. Of these 57 patients, 70.2% had history of diabetes mellitus, 26.3% had history of heavy alcohol use, 22.8% had chronic kidney disease, 47.3% with obesity, and 21.1% with metabolic syndrome. Two patients were classified as unexplained HTG. Secondary analysis showed a total of 45.6% of patients requiring ICU admission. 26.3% of patients with severe inflammatory pancreatitis and 17.5% of patients with severe necrotizing pancreatitis.ConclusionsIn our cohort of HIAP, 55 out of 57 patients had secondary causes for HTG. Identifying secondary causes of HTG during acute hospitalization is important to tailor outpatient treatment in order to prevent future admissions with HIAP.  相似文献   
5.
The objectives of this study are to report the findings in prostatic needle biopsies positive for cancer seen in our practice with regard to the frequency of cancer detected at various sites, the cancer volume, Gleason grade, presence of perineural invasion, and others; to correlate cancer volume with Gleason grade, perineural invasion, and serum prostate-specific antigen (PSA) levels; and to correlate Gleason grade with serum PSA levels. The study was conducted at The Section of Histopathology, Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan. All consecutive needle biopsies received from January 1, 2011 to June 30, 2012, which were positive for prostatic adenocarcinoma, were included in the study. Statistical analysis was carried out using SPSS 19.0 software package (SPSS Hong Kong Headquarters, Quarry Bay, Hong Kong). A total of 97 needle biopsies positive for carcinoma in this period were included. Prostate-specific antigen levels were available in 60.8% cases and ranged from 5.0 to 1747 ng/mL. Tumor was bilaterally present in 54.6% cases. Tumor positivity in right apex, mid, and base was 52.6%, 54.6%, and 51.5%, respectively. Tumor positivity in left apex, mid, and base was 55.7%, 63.9%, and 59.8%, respectively. Average tumor volume in right apex, mid, and base was 51.2%, 50.6%, and 49.9%, respectively. Average tumor volume in left apex, mid, and base was 49.8%, 49.1%, and 51.6%, respectively. Gleason score was 6 in 52.6% cases and 7 in 28.9% cases. Perineural invasion was positive in 46.4% cases. High-grade prostatic intraepithelial neoplasia was seen in 4 (4.1%) of 97 cases. On statistical analysis, no significant correlation was found between tumor volume and serum PSA levels. However, significant correlation was found between tumor volume and Gleason grade and between tumor volume and presence of perineural invasion. No significant correlation was found between Gleason grade and serum PSA level. To our knowledge, these are the first reported findings in prostatic needle biopsies from Pakistan. Most prostatic carcinomas in our country are still diagnosed on transurethral resection specimens, and needle biopsies are quite uncommon. Findings in needle biopsies will help in predicting adverse prognostic factors on radical prostatectomies and in planning surgery accordingly.  相似文献   
6.
7.
The uterovaginal junction, part of the reproductive duct, was studied in domestic hens, specifically the special tubular structures known as the sperm host gland. The results were compared between two groups—non-embryonated and embryonated egg producers. Relevant samples were collected, processed to paraffin wax blocks, and sections cut and stained with H&E and PAS stains. Two types of glands were observed in the lamina propria and submucosa. The results from the sperm host glands in chicken’s oviduct suggested that it might have a functional role in oviductal sperm storage in and release of spermatozoa from the sperm host glands of native hens. Sperm storage structures in the form of tubules are observed in the wall of the uterovaginal junction. These tubules are lined by both ciliated and secretory cells and may play a role in the storage of sperm. These features showed better development in the group of egg-laying hens producing embryonated eggs in comparison to the ones producing non-embryonated eggs.  相似文献   
8.

BACKGROUND AND PURPOSE

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are intracellular Ca2+ channels. Interactions of the commonly used antagonists of IP3Rs with IP3R subtypes are poorly understood.

EXPERIMENTAL APPROACH

IP3-evoked Ca2+ release from permeabilized DT40 cells stably expressing single subtypes of mammalian IP3R was measured using a luminal Ca2+ indicator. The effects of commonly used antagonists on IP3-evoked Ca2+ release and 3H-IP3 binding were characterized.

KEY RESULTS

Functional analyses showed that heparin was a competitive antagonist of all IP3R subtypes with different affinities for each (IP3R3 > IP3R1 ≥ IP3R2). This sequence did not match the affinities for heparin binding to the isolated N-terminal from each IP3R subtype. 2-aminoethoxydiphenyl borate (2-APB) and high concentrations of caffeine selectively inhibited IP3R1 without affecting IP3 binding. Neither Xestospongin C nor Xestospongin D effectively inhibited IP3-evoked Ca2+ release via any IP3R subtype.

CONCLUSIONS AND IMPLICATIONS

Heparin competes with IP3, but its access to the IP3-binding core is substantially hindered by additional IP3R residues. These interactions may contribute to its modest selectivity for IP3R3. Practicable concentrations of caffeine and 2-APB inhibit only IP3R1. Xestospongins do not appear to be effective antagonists of IP3Rs.  相似文献   
9.
The Asian Pacific Association for the Study of the Liver (APASL) Working Party on Portal Hypertension has developed consensus guidelines on the disease profile, diagnosis, and management of noncirrhotic portal fibrosis and idiopathic portal hypertension. The consensus statements, prepared and deliberated at length by the experts in this field, were presented at the annual meeting of the APASL at Kyoto in March 2007. This article includes the statements approved by the APASL along with brief backgrounds of various aspects of the disease.  相似文献   
10.
The rabbit fish is an economically valuable teleost species which lives in shallow coastal waters amongst aquatic plants. Two species of rabbit fish, Siganus sutore and Siganus javus, have been identified in the sea south of Iran. In this study, in order to investigate the histology of the outer layer of the S. javus eye, the eyes of 12 healthy specimens of S. javus were extracted and histologic sections were prepared. The sections were studied under a light microscope after staining with hematoxylin and eosin and Masson's trichrome stains. The outer layer was composed of the cornea cranially and the sclera caudally. The sclera contained an episclera zone and two cartilaginous segments with connective tissue correlation. The cornea included dermal components (stratified cuboidal epithelium, Bowman's membrane, and dermal stroma with occasional flattened cells); the scleral part consisted of two main layers (irregular fibers of connective tissue overlaying the second scleral stroma layer). The fibers of the scleral stroma were the only component present at the posterior part of the cornea. These results reveal that the eye of S. javus does not possess Descemet's membrane or endothelium in the cornea.  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