全文获取类型
收费全文 | 336篇 |
免费 | 22篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 7篇 |
妇产科学 | 10篇 |
基础医学 | 34篇 |
口腔科学 | 10篇 |
临床医学 | 22篇 |
内科学 | 74篇 |
皮肤病学 | 2篇 |
神经病学 | 6篇 |
特种医学 | 28篇 |
外科学 | 25篇 |
综合类 | 3篇 |
预防医学 | 18篇 |
眼科学 | 9篇 |
药学 | 64篇 |
中国医学 | 33篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 20篇 |
2017年 | 7篇 |
2016年 | 14篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 32篇 |
2011年 | 30篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 21篇 |
2007年 | 26篇 |
2006年 | 18篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 16篇 |
2002年 | 5篇 |
2001年 | 12篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有364条查询结果,搜索用时 15 毫秒
21.
Mohamed Waheed Basyouni Adel Mohamed Shabana Wael Mahmoud El Kilani 《The Egyptian Heart Journal》2018,70(4):295-299
Background
Atherosclerosis is progressive and diffuse pathological disorders which can simultaneously affect multiple vascular beds. Diagnosing Lower extremities peripheral arterial disease (PAD) in patients with Coronary artery disease (CAD) admitted to cardiac rehabilitation program can help to tailor exercise regimen to fit these patients, in addition, early treatment and/or intervention may help to control progression of the disease.Aim
The study is to search for the prevalence of undiagnosed PAD using ankle brachial index (ABI) in Egyptian patients with documented CAD undergoing cardiac rehabilitation program.Patients and Methods
The study included 200 patients with documented CAD scheduled for cardiac rehabilitation in Cardiology department, Ain Shams University, with exclusion of patients with known (diagnosed) PAD. All patients underwent ABI using Doppler ultrasonography. The patients were divided into two groups; Study group with positive ABI (≤?0.9) and Control group with negative ABI (>?0.9).Results
We found that the prevalence of undiagnosed PAD in those patients was 14.5% (29 patients). The incidence of PAD is increased in patients above 60 years (p?=?0.001) and in presence of hypertension/uncontrolled systolic blood pressure (p?=?0.002), Dyslipidemia (p?=?0.005), or family history of ischemic heart disease (p?=?0.035). PAD is associated also with impaired left ventricular systolic function and presence of segmental wall motion abnormalities at rest. Impaired eGFR increased the risk of development of PAD (p?=?0.016). PAD was associated more with patients presented by multivessel lesions by coronary angiography and in presence of ischemic ECG changes.Conclusion
This study shows that significant PAD is present in almost 15% of ischemic Egyptian patients. We recommend ABI to be done routinely in patients with significant CAD for exclusion or diagnosis of PAD to help in treatment and improving quality of life in addition to modification of cardiac rehabilitation program in presence of PAD according to its severity. 相似文献22.
The blood group H antigen type 2 was investigated immunohistochemically in sections of 44 surgical specimens from the oral mucosa. These comprised 35 squamous cell carcinomas obtained from 22 patients and 9 specimens of clinically healthy mucosa. The carcinoma specimens included 10 primary lesions and 25 recurrent lesions from patients who had undergone radiotherapy. The results showed that the specimens of normal oral mucosa stained at higher antibody titers than either group of carcinomas, and that postradiation recurrent tumors stained at higher titers than primary tumors. In 10 patients, both preradiation and postradiation carcinomas were examined; the postradiation lesions showed increased reactivity in 5 patients, no change in 3 patients, and a decrease in antigen reactivity in 2 patients. The expression of antigen H type 2 in the recurrent tumors appeared to correlate with the estimated daily tumor radiation dose; tumors with specific antigen staining took twice as long to recur after radiotherapy than tumors without similar staining. The results suggest that the expression of the blood group H antigen type 2 substance, being a differentiation antigen, is enhanced by the effect of radiation on the malignant cell. 相似文献
23.
In a three-dimensional culture model, oral epithelial differentiation was investigated ultrastructurally and biochemically for cytokeratin expression. Epithelia from the hard palate, gingiva and alveolar mucosa grown on freely floating collagen lattices populated with fibroblasts from homotypic origins, and fed with medium containing 10% delipidized fetal calf serum for 21 days before analysis, stratified and differentiated to basal cuboidal cells, polyhydral spinous cells and elongated superficial cells. The epithelium of palatal origin had non-nucleated superficial cells resembling orthokeratinized cells. The upper spinous cells had keratohyalin-like granules. The corresponding cells of gingival and alveolar mucosal origins retained their nuclei and had smaller numbers of keratohyalin-like granules. Basal cell keratins (CK 5 and 14) and those of hyperproliferation (CK 6 and 16) were consistently found in all epithelia. Furthermore, simple epithelial keratins (CK 18 and 19) were variably expressed by cells from different oral origins. In epithelial cells from the alveolar mucosa, CK 13 and 19 formed major bands, which correlates with their expression in vivo. In contrast, these polypeptides were either absent or formed minor bands in extracts of gingival and hard palatal cells. Although in small quantities, keratins of terminal differentiation (CK 1, 2, 10 and 11) were detected in gels prepared from palatal epithelia. This expression correlates with the higher morphological differentiation of these cells in this model. The model is of interest for studies of epithelial differentiation, as the differentiation markers of keratinized epithelia (CK 1 and 10) were expressed by cells from palatal origin, and those of non-keratinized epithelia (CK 4, 13 and 19) were prominent in cells from alveolar mucosal origin. 相似文献
24.
E. F. Shabana 《Journal of basic microbiology》1987,27(4):215-223
Atrazine added in different doses to the culture media, augmented with glucose, of Aulosira fertilissima, Tolypothrix tenuis, Anabaena oryzae and Nostoc muscorum enhanced heterocyst frequency and efficiency of nitrogen fixation. Variations in the amounts of fixed nitrogen between the four test organisms may be attributed to differences in the levels of the high energy substance ATP, and also to various effects on the permeability barrier of cells. Although atrazine is a metabolic inhibitor, it enhanced particularly the nitrogen and phosphorus metabolism, leading to more amino-N and protein-N accumulation, yielding active synthesis of organic phosphorus, total soluble and insoluble phosphorus contents. 相似文献
25.
Gait analysis in the adjuvant-induced arthritic rat model of chronic pain was used to examine the role of GABA(A) receptors in the development of pain. Drug solutions were administered continuously at 5+/-0.75 microl/h for 14 days via Alzet osmotic pumps (2ML2) placed under the skin of the back. The GABA(A) receptor agonist, muscimol, produces a dose-dependent reversal of the gait deficits seen in arthritic rats without reducing the tibiotarsal joints inflammatory edema or the histological picture of joint erosion and inflammation. The higher infusion rate for muscimol, 20 microg/h, caused the gait for the arthritic rats to be indistinguishable from that of normal non-arthritic rats. In normal, non-arthritic rats, muscimol did not show any effect on gait. The GABA(A) receptor antagonist bicuculline showed small but significant exacerbation of stride length (P < 0.05) single and double stance time (P < 0.05) and swing time deficits (P < 0.05) in the arthritic rats, but no changes in measures of gait in the normal control rat. The results suggest that the development of arthritic pain is increased in the absence of GABA(A) receptor tone and that increasing GABA(A) receptor tone can reduce arthritic pain but does not affect the disease process. 相似文献
26.
Khan SI Aumsuwan P Khan IA Walker LA Dasmahapatra AK 《Chemical research in toxicology》2012,25(1):61-73
Aberrant epigenetic alterations in the genome such as DNA methylation and chromatin remodeling play a significant role in breast cancer development. Since epigenetic alterations are considered to be more easily reversible compared to genetic changes, epigenetic therapy is potentially very useful in reversing some of these defects. Methylation of CpG islands is an important component of the epigenetic code, and a number of genes become abnormally methylated in breast cancer patients. Currently, several epigenetic-based synthetic drugs that can reduce DNA hypermethylation and histone deacetylation are undergoing preclinical and clinical trials. However, these chemicals are generally very toxic and do not have gene specificity. Epidemiological studies have shown that Asian women are less prone to breast cancer due to their high consumption of soy food than the Caucasian women of western countries. Moreover, complementary/and or alternative medicines are commonly used by Asian populations which are rich in bioactive ingredients known to be chemopreventive against tumorigenesis in general. Examples of such agents include dietary polyphenols, (-)-epigallocatechin-3-gallate (EGCG) from green tea, genistein from soybean, isothiocyanates from plant foods, curcumin from turmeric, resveratrol from grapes, and sulforaphane from cruciferous vegetables. These bioactive components are able to modulate epigenetic events, and their epigenetic targets are known to be associated with breast cancer prevention and therapy. This approach could facilitate the discovery and development of novel drugs for the treatment of breast cancer. In this brief review, we will summarize the epigenetic events associated with breast cancer and the potential of some of these bioactive dietary components to modulate these events and thus afford new therapeutic or preventive approaches. 相似文献
27.
28.
29.
Nicholas L. Hammond Seoung-ryoung Choi Paulo Carvalho Hua Liu Shabana Khan Mitchell A. Avery 《Medicinal chemistry research》2011,20(4):401-407
Abstract
Malaria is re-emerging in many tropical areas of the world and is often fatal due to drug resistance, leading to about a million deaths each year. Multiple drug resistance has required new efforts in drug discovery and development. Thus, the search for new drugs operating by novel mechanisms of action is receiving increased attention. Herein we report the synthesis and biological evaluation of a novel anti-malarial with micromolar activity against resistant strains of the parasite. 相似文献30.
Li XC Jacob MR Khan SI Ashfaq MK Babu KS Agarwal AK Elsohly HN Manly SP Clark AM 《Antimicrobial agents and chemotherapy》2008,52(7):2442-2448
Our continuing effort in antifungal natural product discovery has led to the identification of five 6-acetylenic acids with chain lengths from C(16) to C(20): 6-hexadecynoic acid (compound 1), 6-heptadecynoic acid (compound 2), 6-octadecynoic acid (compound 3), 6-nonadecynoic acid (compound 4), and 6-icosynoic acid (compound 5) from the plant Sommera sabiceoides. Compounds 2 and 5 represent newly isolated fatty acids. The five acetylenic acids were evaluated for their in vitro antifungal activities against Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, Candida parapsilosis, Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Trichophyton mentagrophytes, and Trichophyton rubrum by comparison with the positive control drugs amphotericin B, fluconazole, ketoconazole, caspofungin, terbinafine, and undecylenic acid. The compounds showed various degrees of antifungal activity against the 21 tested strains. Compound 4 was the most active, in particular against the dermatophytes T. mentagrophytes and T. rubrum and the opportunistic pathogens C. albicans and A. fumigatus, with MICs comparable to several control drugs. Inclusion of two commercially available acetylenic acids, 9-octadecynoic acid (compound 6) and 5,8,11,14-eicosatetraynoic acid (compound 7), in the in vitro antifungal testing further demonstrated that the antifungal activities of the acetylenic acids were associated with their chain lengths and positional triple bonds. In vitro toxicity testing against mammalian cell lines indicated that compounds 1 to 5 were not toxic at concentrations up to 32 muM. Furthermore, compounds 3 and 4 did not produce obvious toxic effects in mice at a dose of 34 mumol/kg of body weight when administered intraperitoneally. Taking into account the low in vitro and in vivo toxicities and significant antifungal potencies, these 6-acetylenic acids may be excellent leads for further preclinical studies. 相似文献