全文获取类型
收费全文 | 376篇 |
免费 | 50篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 18篇 |
妇产科学 | 7篇 |
基础医学 | 61篇 |
口腔科学 | 5篇 |
临床医学 | 28篇 |
内科学 | 73篇 |
皮肤病学 | 24篇 |
神经病学 | 6篇 |
特种医学 | 2篇 |
外科学 | 22篇 |
综合类 | 23篇 |
预防医学 | 70篇 |
眼科学 | 6篇 |
药学 | 39篇 |
中国医学 | 31篇 |
肿瘤学 | 10篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 18篇 |
2015年 | 9篇 |
2014年 | 18篇 |
2013年 | 23篇 |
2012年 | 42篇 |
2011年 | 30篇 |
2010年 | 23篇 |
2009年 | 15篇 |
2008年 | 29篇 |
2007年 | 17篇 |
2006年 | 13篇 |
2005年 | 18篇 |
2004年 | 25篇 |
2003年 | 14篇 |
2002年 | 13篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有428条查询结果,搜索用时 15 毫秒
41.
Effects of Substance P on spontaneous contractions of the circular muscle of the flexure region of guinea pig colon were studied by mechanical tension recording. Substance P (3 nM-10 nM) produced tonic contraction associated with phasic activities but the contraction was found stronger at higher concentration. Verapamil (3 microM), a voltage dependent L-type Ca(2+) channel blocker completely blocked the spontaneous activities and also Substance P induced contraction. These results suggest that Substance P produce contraction by Ca(2+) influx and the Ca(2+) influx occurs by activating verapamil sensitive Ca(2+) channel. 相似文献
42.
Talukder SI Haque MA Huq MH Alam MO Roushan A Noor Z Nahar K 《Mymensingh medical journal : MMJ》2007,16(1):81-84
The objective of this study was to explore the histopathological findings and the rate of removal of ovaries in hysterectomy specimens. This study took into account 328 hysterectomy specimens examined in the Department of Pathology, Mymensingh Medical College and in one private Pathology Laboratory in Mymensingh town from March to August, 2005. Formalin fixed paraffin embedded tissue sections stained with haematoxylin and eosin were examined under light microscope. Patients' age, parts of uterus examined and their histopathological findings were retrieved from laboratory records. The common histopathological findings were: chronic cervicitis (87.80%), leiomyoma (17.07%), uterine prolapse (16.72%), adenomyosis (3.96), non-specific endometritis (3.35%), squamous cell carcinoma of cervix (2.44%), endometrial polyp (2.44%), serous cystadenoma of ovary (2.44%) and endometrial hyperplasia (1.83%). Some of the specimens show more than one lesions in the body of uterus, of which coexistence of adenomyosis and leiomyoma was the most common. Neoplastic lesions in cervix were 4.27%, in body 16.92% and in ovaries 5.06%. Malignant neoplasms were found in cervix 71.43%, in uterine corpus 3.03% and in ovaries 25%. Ovaries of both sides were removed in 48.17% of total cases. Their median age was 45 years, lowest age 23 years and maximum age was 82. The rate of removal of both ovaries was found to be increasing with the increase of age. Only one case was found to be subtotal hysterectomy and others were total hysterectomy. The present study revealed that the most common histopathological cause of hysterectomy is chronic cervicitis. Most common neoplastic cause of hysterectomy is leiomyoma. The rationalities and the possible after effect of hysterectomy in sexual functions and other physiological impairment should be followed up. 相似文献
43.
T2182C mutation in 23S rRNA is associated with clarithromycin resistance in Helicobacter pylori isolates obtained in Bangladesh 总被引:8,自引:0,他引:8
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Khan R Nahar S Sultana J Ahmad MM Rahman M 《Antimicrobial agents and chemotherapy》2004,48(9):3567-3569
Twelve clarithromycin-resistant (MIC, > or = 1 microg/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance. 相似文献
44.
P C Singhal R T Sankaran N Nahar N Shah P Patel 《Journal of investigative medicine》2000,48(2):110-117
BACKGROUND: Macrophages seem to play an important role in the development of glomerulosclerosis. In both human and experimental animal models of focal glomerulosclerosis (FSGS), infiltration of macrophages in the mesangium has been considered key in the development of FSGS. METHODS: In the present study, we evaluated the effect of vasoactive agents on the migration of monocytes across a filter in a modified Boyden chamber as well as across a cultured glomerular endothelial cell layer (in vitro model of glomerular mesangium). Both light as well as scanning electron microscopic studies were performed. We evaluated the effect of vasoactive agents including histamine, prostaglandin (PG) E2, angiotensin II, endothelin-1, platelet-activating factor, and interleukin-1 (IL) on the migration of monocytes/macrophages across an endothelial cell layer as well as a gelatin-coated filter. In addition, we evaluated the effect of cyclic adenosine 3',5' cyclic monophosphate (cAMP) and PGE2 on vasoactive-induced migration of monocytes. RESULTS: Histamine increased (P < 0.003) the migration of monocytes across the filter. This effect of histamine was dose-dependent. Histamine at concentrations of 10(-8) to 10(-5) mol/L induced optimal migration across the filter (control, 16.6 +/- 1.1 vs histamine, 10(-8) mol/L, 40.9 +/- 0.9 monocytes/high power field). Cimetidine, an H2 receptor blocker, attenuated (P < 0.001) the effect of histamine on the migration of monocytes. PGE2 inhibited the migration of monocytes in a dose-dependent manner. Histamine increased (P < 0.001) the passage of monocytes across the glomerular endothelial cell layer (control, 1012 +/- 37 vs 1711 +/- 163 cpm/well). Histamine also increased the migration of murine macrophages across the glomerular endothelial cell layer. PGE2 inhibited the migration of monocytes across the endothelial cell layer under basal as well as histamine-stimulated states. Dibutyryl cyclic (DBc) AMP also attenuated the migration of monocytes under basal as well as histamine-stimulated states. Both PGE2 and DBcAMP also attenuated the IL-1 beta-stimulated migration of monocytes. Angiotensin II, endothelin-1, and platelet-activating factor did not modulate the migration of monocytes. CONCLUSIONS: Vasoactive agents directly modulate the transmigration of monocytes. The present in vitro study provides a basis for a hypothesis that vasoactive agents may also be modulating the migration of monocytes across the glomerular endothelial cell layer (into the mesangium). 相似文献
45.
Comparative Cytotoxicity of Glycyrrhiza glabra Roots from Different Geographical Origins Against Immortal Human Keratinocyte (HaCaT), Lung Adenocarcinoma (A549) and Liver Carcinoma (HepG2) Cells
下载免费PDF全文
![点击此处可从《Phytotherapy research : PTR》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Norazah Basar Olayinka Ayotunde Oridupa Kenneth J. Ritchie Lutfun Nahar Nashwa Mostafa M. Osman Angela Stafford Habibjon Kushiev Asuman Kan Satyajit D. Sarker 《Phytotherapy research : PTR》2015,29(6):944-948
Glycyrrhiza glabra L. (Fabaceae), commonly known as ‘liquorice’, is a well‐known medicinal plant. Roots of this plant have long been used as a sweetening and flavouring agent in food and pharmaceutical products, and also as a traditional remedy for cough, upper and lower respiratory ailments, kidney stones, hepatitis C, skin disorder, cardiovascular diseases, diabetes, gastrointestinal ulcers and stomach ache. Previous pharmacological and clinical studies have revealed its antitussive, antiinflammatory, antiviral, antimicrobial, antioxidant, immunomodulatory, hepatoprotective and cardioprotective properties. While glycyrrhizin, a sweet‐tasting triterpene saponin, is the principal bioactive compound, several bioactive flavonoids and isoflavonoids are also present in the roots of this plant. In the present study, the cytotoxicity of the methanol extracts of nine samples of the roots of G. glabra, collected from various geographical origins, was assessed against immortal human keratinocyte (HaCaT), lung adenocarcinoma (A549) and liver carcinoma (HepG2) cell lines using the in vitro 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazoliumbromide cell toxicity/viability assay. Considerable variations in levels of cytotoxicity were observed among various samples of G. glabra. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
46.
47.
Liu WM Nahar TE Jacobi RH Gijzen K van Beek J Hak E Jonges M Boog CJ van der Zeijst BA Soethout EC 《Vaccine》2012,30(9):1659-1666
Seasonal influenza causes more morbidity and mortality in older adults than in young adults, apparently because of a decline in immune function with increasing age, known as immunosenescence. In this study, we compared the capacity of dendritic cells (DCs) from healthy older adults (≥65 years) with DCs from healthy young adults (20-40 years) to initiate a T cell response against influenza. DCs from older adults were impaired in the induction of influenza-specific CD8+ T cells as compared to DCs from young adults, which was demonstrated by a decreased proliferation, an impaired production of IFN-γ and a reduced expression of the degranulation marker CD107a by CD8+ T cells. Importantly, DCs from older adults produced significantly less TNF-α, showed a decreased expression of HLA class I and had a lower maturation state after influenza virus infection. Supplementing TNF-α increased the expression of HLA class I and of maturation markers and enhanced the induction of the influenza-specific CD8+ T cell response. Together, these findings indicate that the impaired influenza-specific CD8+ T cell response in older adults is associated with a reduced production of TNF-α and with a lower DC maturation. We suggest that the production of TNF-α is a determining factor in the DC-mediated CD8+ T cell response against influenza. 相似文献
48.
49.
Uma Nahar Saikia Baijayantimala Mishra Mirnalini Sharma Ritambhra Nada BD Radotra 《Diagnostic microbiology and infectious disease》2014
Coxsackieviral myocarditis is associated with systemic involvement in neonates; however, fulminant coxsackieviral myocarditis is rare in adults, and its dissemination with fatal myocarditis involving kidneys, liver, and adrenal is further rarely reported. We report a case of fulminant myocarditis along with dissemination of coxsackievirus, which was clinically unrecognized. 相似文献
50.
Nahar M Dutta T Murugesan S Asthana A Mishra D Rajkumar V Tare M Saraf S Jain NK 《Critical reviews in therapeutic drug carrier systems》2006,23(4):259-318
Nanotechnology is a multidisciplinary field and has achieved breakthroughs in bioengineering, molecular biology, diagnostics, and therapeutics. A recent advance in nanotechnology is the development of a functional nanosystem by incorporation, adsorption, or covalent coupling of polymers, carbohydrates, endogenous substances/ligands, peptides, proteins, nucleic acids, and polysaccharides to the surface of nanoparticles. Functionalization confers a wide array of interesting properties such as stealth characteristics, a bioadhesive property, and that it prevents aggregation of nanoparticles, imparts biostability and solubility, reduces toxicity, and provides site-specific delivery. This makes the nanosystem an intelligent tool for diagnostics, prognostics, and controlled and sustained delivery of protein, peptide, pDNA, and other therapeutic agents to specific targets (tissue, cell, and intracellular). Various types of functional nanosystems, such as carbon nanotubes, quantum dots, polymeric micelles, dendrimers, metallic nanoparticles, and liposomes, are being extensively explored. However, high tissue accumulation of nonbiodegradable nanoparticles has caused toxicity problems and rendered them as not-so-popular therapeutic and diagnostic systems. The toxicity and safety of nonbiodegradable nanoparticles are subject to future research. Polymeric nanoparticles have offered attractive alternative modules due to biocompatibility, nonimmunogenicity, nontoxicity, biodegradability, simple preparation methods, high physical stability, possibility of sustained drug release, and higher probability for surface functionalization. Depending on properties that have been modified, polymeric nanoparticles can be grouped in to four classes, namely, stealth, polysaccharide decorated biomimetic, bioadhesive, and ligand-anchored functional polymeric nanoparticles (f-PNPs). This review explores the ligand-anchored f-PNP as a carrier for active delivery of bioactives, envisaged to date. This review also details the ligands available for conjugation, their method of coupling to nanoparticles, and applications of f-PNPs in anticancer drug delivery, oral delivery, gene delivery, vaccine delivery, and intracellular delivery; site-specific delivery to liver, macrophages, lymphatics, and brain; and miscellaneous applications. This review also addresses formidable challenges encountered, and proposes some future strategies for development of a promising site-specific active delivery system. 相似文献