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   366篇
  免费   18篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   23篇
基础医学   59篇
口腔科学   11篇
临床医学   23篇
内科学   60篇
皮肤病学   4篇
神经病学   24篇
特种医学   4篇
外科学   35篇
综合类   23篇
预防医学   55篇
眼科学   4篇
药学   24篇
中国医学   6篇
肿瘤学   20篇
  2023年   3篇
  2022年   6篇
  2021年   36篇
  2020年   12篇
  2019年   24篇
  2018年   26篇
  2017年   20篇
  2016年   15篇
  2015年   21篇
  2014年   13篇
  2013年   23篇
  2012年   24篇
  2011年   16篇
  2010年   13篇
  2009年   20篇
  2008年   17篇
  2007年   21篇
  2006年   12篇
  2005年   10篇
  2004年   10篇
  2003年   11篇
  2002年   6篇
  2001年   5篇
  2000年   3篇
  1999年   2篇
  1997年   2篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
排序方式: 共有385条查询结果,搜索用时 125 毫秒
11.
The Principles of Green Chemistry was employed for the preparation of organic antiseptic soaps with improved skin sensitivity, reduced skin toxicity and improved biodegradability. Non-conventional and lesser known tropical seeds of Momordica charantia were used as the source of oil for the saponification processes. The fatty acid methyl esters of the oil were prepared via transesterification and subjected to GC–MS analysis to obtain the fatty acid composition of the oil and saponified products were subjected to various physicochemical and antimicrobial evaluations. The results indicated that stearic acid (18:0) and eleostearic acid (18:3) were the most abundant fatty acids making up 37.60% and 39.16%, respectively. Palmitic acid (16:0) 12.36%, oleic acid (18:1) 8.71%, linoleic acid (18:2) 0.67% and gamolenic acid (18:3) 1.50% were present in smaller amount in the oil. The oil is a viable source of polyunsaturated fatty acid which is required as essential fatty acids in the human body. The prepared soaps containing only natural additives (such as honey and shear butter) and components showed appreciable degree of hardness comparable to commercial Dudu Osun and the synthetic Lux soaps used as standards. This work demonstrates the probability of the preparation of green antiseptic soaps from the underutilized tropical seed of M. charantia. The seed oil and the allied products obviously have great potential for further advancement, development, research and applications in health and cosmetics sectors. The adopted approach could also assist maintaining a safe and healthy biotic and abiotic environment.  相似文献   
12.
13.
The insidious nature of Zika virus (ZIKV) infections can have a devastating consequence for fetal development. Recent reports have highlighted that chloroquine (CQ) is capable of inhibiting ZIKV endocytosis in brain cells. We applied pharmacokinetic modeling to develop a predictive model for CQ exposure to identify an optimal maternal/fetal dosing regimen to prevent ZIKV endocytosis in brain cells. Model validation used 13 nonpregnancy and 3 pregnancy clinical studies, and a therapeutic CQ plasma window of 0.3-2 μM was derived. Dosing regimens used in rheumatoid arthritis, systemic lupus erythematosus, and malaria were assessed for their ability to target this window. Dosing regimen identified that weekly doses used in malaria were not sufficient to reach the lower therapeutic window; however, daily doses of 150 mg achieved this therapeutic window. The impact of gestational age was further assessed and culminated in a final proposed regimen of 600 mg on day 1, 300 mg on day 2 and 3, and 150 mg thereafter until the end of trimester 2, which resulted in maintaining 65% and 94% of subjects with a trough plasma concentration above the lower therapeutic window on day 6 and at term, respectively.  相似文献   
14.
The effects of oral and intravenous administration of the stem bark extract of Vitex doniana on blood pressure was investigated in normotensive and hypertensive rats. Oral and intravenous administration of the stem bark extract produced a dose-dependent hypotensive effect in both normotensive and hypertensive rats. The blood pressure was markedly reduced and the reduced level maintained for longer duration when the extract was administered intravenously to hypertensive rats. The present data show that the extract affects the smooth muscle of the vascular system, suggesting a possible therapeutic application as an antihypertensive agent.  相似文献   
15.
BackgroundNeovascular glaucoma (NVG), a form of secondary glaucoma has varying causes across geographical locations.ObjectiveThe objective of this study was to determine the presentation, aetiology, and outcome of treatment of patients with NVG in a Nigerian tertiary hospital.MethodA retrospective review of records of all cases of NVG seen over a 5year period was carried out. Demographic characteristics, presenting visual acuity and coexisting ocular and systemic conditions were noted. Data were analysed with Statistical Package for Social Sciences (SPSS) version 25.Results29 eyes of patients with NVG were analysed. Most of the patients (89.70%) presented with visual acuity less than 3/60 in the affected eye. All patients except one were treated with anti-glaucoma medications while only 9(31%) consented to and received anti-vascular endothelial growth factor. No patient had improvement in visual acuity despite resolution of other symptoms at 12week follow up.ConclusionNVG though not as common as other forms of glaucoma accounted for a large proportion of monocular blindness in the affected eyes at presentation. There is need for health promotion and education among our people on the need for early preventive eye check practices.  相似文献   
16.
Hepatitis B virus (HBV) infection is a major public health problem for over two billion people infected globally. Occupationally exposed persons are at high risk of HBV infection and, apart from medical personnel, there is dearth of information concerning the prevalence and awareness of HBV among this population in Nigeria. This study was designed to determine the levels of HBV awareness and prevalence of HBV infection among hairdressers in Ibadan, Nigeria. Hairdressers and teachers (unmatched controls) in four local government areas in Ibadan were tested for HBV infection using ELISA technique. Dried blood spot (DBS) samples were collected from 171 participants. DBS elutes from the samples were tested for HBV surface antigen (HBsAg). The rate of HBV infection was higher (p = 0.005) among the hairdressers (13.0%) than teachers (4.8%). However, teachers were better informed about HBV (38%) compared to hairdressers (13%; p = 0.0001). Differences in HBV awareness and occupation type were found to be significant (P = 0.001). Hairdressers are at high risk of HBV infection and may constitute a major source of HBV spread among urban dwellers, especially in areas where awareness is low. Routine HBV screening and appropriate interventions for hairdressers are recommended to interrupt HBV transmission.  相似文献   
17.
The inhibition of apoptosis is a critical event in the development of colorectal malignancies, although the mechanism(s) remain incompletely understood. The anti-apoptotic proto-oncogene, AKT, has been implicated in the molecular pathogenesis of a variety of human malignancies; however, no data exist on the role of AKT in colon carcinogenesis. We therefore evaluated the presence of AKT in human and experimental colon neoplasms by immunohistochemistry. Normal colonic mucosa and hyperplastic polyps exhibited no significant AKT expression, in marked contrast to the dramatic AKT immunoreactivity seen in colorectal cancers (57% positive) and in both human colorectal cancer cell lines examined. Importantly, AKT was also detected in 57% of the adenomas examined, implicating overexpression of this proto-oncogene as an early event during colon carcinogenesis. Moreover, in the rodent-carcinogen model, azoxymethane (AOM)-treatment induced AKT expression in premalignant rat colonocytes. Tumors that evolve via different genetic pathways displayed a lower incidence of AKT overexpression. Indeed, only 22% of mismatch repair defective tumors and 42% of AOM-induced rodent tumors upregulated AKT. Staining with an antibody specific for AKT 2 duplicated findings with the AKT 1&2 antibody, suggesting that AKT 2 was the predominant isoform involved in colon carcinogenesis. Furthermore, utilizing an antibody that specifically recognizes the serine-473 phosphorylated form of AKT, we observed that activated AKT was detectable in the neoplastic but not normal epithelium. In summary, our immunohistochemical analysis indicates AKT overexpression occurs frequently during human colon carcinogenesis, but is less common in colon cancers with microsatellite instability. The early inhibition of apoptosis during sporadic colon carcinogenesis may be related, at least partly, to the overexpression of AKT.  相似文献   
18.
The in vivo antiplasmodial, analgesic and anti-inflammatory properties of Erythrina senegalensis, an ornamental plant commonly used in Northern Nigeria for the treatment of fevers, was evaluated. Aqueous extracts of the stem bark of the plant was used for the study. The in vivo antiplasmodial activity of the aqueous extract against Plasmodium berghei was assessed using the suppressive and curative test procedures. Analgesic activity was assessed using the acetic acid (0.75%v/v) induced abdominal constriction, while the anti-inflammatory activity was evaluated on egg-albumin induced paw oedema in rats as a model of acute inflammation. The stem bark extract of E. senegalensis exhibited only slight antiplasmodial activity while significant (P<0.05) analgesic and anti-inflammatory effects were observed. Preliminary phytochemical analysis of the extract indicates the presence of alkaloids and glycosides.  相似文献   
19.
Risk factors for ectopic pregnancy in Lagos, Nigeria   总被引:14,自引:0,他引:14  
BACKGROUND: Ectopic pregnancy is an important cause of maternal deaths in Nigeria and in other developing countries. In Lagos, Nigeria, it is responsible for 8.6% of maternal deaths, and has a case fatality rate of 3.7%. The purpose of this study was to determine the risk factors for ectopic pregnancy in Lagos. METHODS: A case-control study of 100 patients and 280 controls was performed in the three hospitals--Lagos University Teaching Hospital, Ayinke House Maternity Hospital, and Lagos Island Maternity Hospital--in Lagos from June 1999 to December 1999. Data were analyzed by using logistic regression. RESULTS: The incidence was 23.1/1000 (1 : 43) deliveries and was responsible for 48.5% of gynecologic emergencies. Age, marital status, socioeconomic status, and parity were not the significant risk factors for ectopic pregnancy. An early age of sexual debut increased the risk of ectopic pregnancy almost two-fold (adjusted OR = 1.93; 95% CI = 1.71-2.93), whereas a late age of sexual debut was protective (adjusted OR = 0.37; 95% CI = 0.19-0.59). History of multiple lifetime sexual partners, induced abortions, pelvic inflammatory disease, sexually transmitted disease (STD), miscarriage, and pelvic surgery independently and significantly increased the risk of ectopic pregnancy. Induced abortion and STD increased the risk 14-fold and nine-fold, respectively. Previous use of intrauterine contraceptive device increased the risk almost four-fold (adjusted OR = 3.76; 95% CI = 2.12-6.69), whereas the use of condoms was protective (adjusted OR = 0.35; 95% CI = 0.17-0.71). CONCLUSIONS: Proper sex education, prevention of unwanted pregnancy, and prevention and proper treatment of sexually transmitted infections will reduce the incidence of ectopic pregnancy.  相似文献   
20.
OBJECTIVES: This study aims to highlight the problems associated with impacted acrylic dentures and proffers advice to check them. PATIENTS AND METHODS: Retrospective review of all cases of impacted acrylic dentures over a 16-year period. RESULTS: Twenty-two adults had impacted esophageal acrylic dentures of which 16 (72.7%) and six (27.3%) were males and females, respectively (M:F ratio = 2.7:1) with age range 23-77 years. Fourteen patients (63.6%) had worn their dentures for more than 10 years without check-up, and 54.5% presented within 48 hours of impaction. The common symptoms in all the patients were difficulty with swallowing, throat pain and discomfort, followed by tenderness in the neck in 15 (68.2%). Dentures were extracted through esophagoscopy (17 cases) and cervical (three cases) esophagotomy, respectively. Observed complications included pulmonary edema in one and esophageal perforation in five patients. CONCLUSION: Endoscopic extraction of dentures carries a high risk of perforation. Extraction of an impacted denture via esophagoscopy can be undertaken under direct vision and in an ideal situation with judicious use of the Shears forceps. In the absence of these, the safest option is an esophagotomy. Proper treatment planning in the fabrication of dentures with incorporation of radiopaque materials in the dental resins and adequate postdenture delivery instructions are necessary as preventive measures.  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