全文获取类型
收费全文 | 12993篇 |
免费 | 1180篇 |
国内免费 | 829篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 90篇 |
妇产科学 | 17篇 |
基础医学 | 941篇 |
口腔科学 | 13篇 |
临床医学 | 1535篇 |
内科学 | 6269篇 |
皮肤病学 | 24篇 |
神经病学 | 59篇 |
特种医学 | 475篇 |
外国民族医学 | 1篇 |
外科学 | 960篇 |
综合类 | 2418篇 |
现状与发展 | 5篇 |
预防医学 | 490篇 |
眼科学 | 6篇 |
药学 | 958篇 |
11篇 | |
中国医学 | 517篇 |
肿瘤学 | 212篇 |
出版年
2024年 | 26篇 |
2023年 | 170篇 |
2022年 | 294篇 |
2021年 | 415篇 |
2020年 | 442篇 |
2019年 | 345篇 |
2018年 | 386篇 |
2017年 | 398篇 |
2016年 | 604篇 |
2015年 | 581篇 |
2014年 | 920篇 |
2013年 | 938篇 |
2012年 | 844篇 |
2011年 | 918篇 |
2010年 | 710篇 |
2009年 | 711篇 |
2008年 | 654篇 |
2007年 | 635篇 |
2006年 | 658篇 |
2005年 | 565篇 |
2004年 | 414篇 |
2003年 | 408篇 |
2002年 | 384篇 |
2001年 | 341篇 |
2000年 | 283篇 |
1999年 | 215篇 |
1998年 | 219篇 |
1997年 | 197篇 |
1996年 | 190篇 |
1995年 | 142篇 |
1994年 | 132篇 |
1993年 | 133篇 |
1992年 | 122篇 |
1991年 | 86篇 |
1990年 | 76篇 |
1989年 | 62篇 |
1988年 | 63篇 |
1987年 | 53篇 |
1986年 | 47篇 |
1985年 | 41篇 |
1984年 | 30篇 |
1983年 | 14篇 |
1982年 | 22篇 |
1981年 | 25篇 |
1980年 | 15篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 13篇 |
1975年 | 7篇 |
1972年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Association of TNF-beta polymorphism with disease severity among patients infected with hepatitis C virus 总被引:2,自引:0,他引:2
Goyal A Kazim SN Sakhuja P Malhotra V Arora N Sarin SK 《Journal of medical virology》2004,72(1):60-65
The pathogenesis of chronic hepatitis C virus (HCV) infection remains unclear. Tumour necrosis factor alpha (TNF-alpha) is alleged to contribute in the pathogenesis of chronic HCV infection. Single nucleotide polymorphism in TNF-alpha and -beta genes could influence the outcome of HCV infection. The aim was to study single nucleotide polymorphism in TNF-alpha promoter region and Nco I polymorphisms in the TNF-beta gene in patients with chronic hepatitis C. Fifty-two patients with histologically proven chronic hepatitis, who had raised ALT levels (>1.5 x ULN) and were HCV RNA positive, were studied. Genotyping of -308 promoter variant of TNF-alpha was performed by PCR with primers that incorporated an Nco I restriction site. For PCR typing of the TNF-beta Nco I restriction fragment length polymorphism, sequence specific primers were used. Polymorphism in the TNF-alpha G/G, G/A and A/A allele was not different between HCV patients and healthy controls. TNF-beta A/A allele was significantly more common (P = 0.02) in patients (28.8%) as compared to controls (12.8%), whereas no significant difference was observed for TNF-beta G/A and G/G alleles [corrected]. Nco I TNF-beta A/A was strongly associated with -308 TNF-alpha G/G (RR of HCV persistence = 4.9), indicating possible linkage between TNF-beta A/A and TNF-alpha G/G allele. Patients with severe hepatic fibrosis more frequently had the TNF-beta A/A allele as compared to patients with mild disease (P = 0.04). Immunogenetic factors, such as single nucleotide polymorphisms in TNF-beta (A/A allele), may affect the natural course of HCV infection, in particular, the disease progression. Larger studies including cytokine expression profiles are needed to fully understand the contribution of the polymorphisms described in the pathogenesis of chronic hepatitis C. 相似文献
52.
Nishioji K Okanoue T Itoh Y Narumi S Sakamoto M Nakamura H Morita A Kashima K 《Clinical and experimental immunology》2001,123(2):271-279
To clarify the role of IP-10 in autoimmune liver diseases, we studied the serum levels of IP-10 in 14 patients with autoimmune hepatitis (AIH), 23 patients with primary biliary cirrhosis (PBC), and 65 patients with chronic viral hepatitis (20 type B and 45 type C). The hepatic expression of IP-10 mRNA and the correlation between the serum levels of IP-10 and clinical parameters were also evaluated. In addition to 20 healthy controls, 16 rheumatoid arthritis (RA) patients were included as an extrahepatic inflammatory disease. The serum level of IP-10 was significantly (P < 0.02) higher in patients with AIH, PBC, and chronic hepatitis B and C than in healthy controls, and it was significantly correlated (P < 0.05) with the serum levels of aspartate aminotransferase and alanine aminotransferase in patients with AIH, PBC, and chronic hepatitis B and C. The serum level of IP-10 was not elevated in RA patients. After successful treatment of AIH and chronic hepatitis C, the serum level of IP-10 decreased to the same level as in healthy volunteers. As we previously showed in cases with chronic hepatitis B or C, in situ hybridization in both AIH and PBC cases demonstrated the expression of IP-10 mRNA in hepatocytes around focal or lobular necrosis surrounded by infiltrating mononuclear cells, whereas IP-10 mRNA was not expressed in areas around the damaged bile ducts in PBC cases. The present results suggest that IP-10 is specifically produced by hepatocytes in inflammatory areas irrespective of the aetiology of hepatitis, and that IP-10 may help to recruit T cells to the hepatic lesions in autoimmune liver diseases as well as in chronic viral hepatitis. 相似文献
53.
Effekte einer Captopriltherapie auf die Natrium- und Wasserausscheidung bei Patienten mit Leberzirrhose und Aszites 总被引:1,自引:0,他引:1
R. Brunkhorst E. Wrenger K. Kühn F. W. Schmidt K. Koch 《Journal of molecular medicine (Berlin, Germany)》1989,67(15):774-783
Summary Ascites in patients with cirrhosis of the liver frequently is refractory to diuretic treatment. It was postulated that vasoconstriction of the renal cortex, mediated by activation of the renin-angiotensin-aldosterone-system (RAAS), may be one course of the disturbed sodium- and water-excretion in these patients. We therefore investigated in 14 cirrhotic patients with ascites under constant diuretic treatment the effects of low-dose captopril therapy on urinary sodium- and potassium-excretion, body weight, abdominal girth, serum-sodium,-potassium, creatinine-clearance, plasma-renin-activity (PRA), plasma-aldosterone (PA) and mean arterial pressure (MAP). After a control period of 4 days the patients received 2 × 6.25 mg/d captopril for 5 days and 4 × 6.25 mg/d for further 5 days. Treatment was followed by a second control period without captopril.PRA increased significantly after 2 days of captopril treatment. 2 × 6.25 mg/d captopril induced a significant increase in sodium excretion and a significant decrease of body weight. MAP decreased slightly but significantly without clinical signs of hypotension. 4 × 6.25 mg/d captopril resulted in a further reduction of body weight and a further enhancement of sodium excretion. Three days after withdrawal of captopril sodium output was significantly reduced again. Conclusion: In cirrhotic patients low-dose captopril seems to be efficient in the treatment of ascites resistant to diuretics without causing major side effects.
Abkürzungen ACE Angiotensin-Converting-Enzym - A-II Angiotensin II - CH 2 O Frei-Wasser-Clearance - CKrea Kreatinin-Clearance - COsmo Osmolale Clearance - g Gramm - h Stunde - kg Kilogramm - l/d Liter pro Tag - MAP Mittlerer arterieller Blutdruck - mg Milligramm - mg/d Milligramm pro Tag - ml/min Milliliter pro Minute - mmHg Millimeter Quecksilbersäule (Torr) - mmol/d Millimol pro Tag - NaCl Natriumchlorid - ng/ml/h Nanogramm pro Milliliter und Stunde - PA Plasma-Aldosteron - pg/ml Picogramm pro Milliliter - PRA Plasma-Renin-Aktivität - RAAS Renin-Angiotensin-Aldosteron-System - SEM Standardfehler des Mittelwertes - SKrea Kreatininkonzentration im Serum - SOsm Serum-Osmolalität - UKrea Kreatininkonzentration im Urin - UOsm Urin-Osmolalität - V Urinminutenvolumen - vgl. vergleiche - µmol/l Micromol pro Liter 相似文献
Abkürzungen ACE Angiotensin-Converting-Enzym - A-II Angiotensin II - CH 2 O Frei-Wasser-Clearance - CKrea Kreatinin-Clearance - COsmo Osmolale Clearance - g Gramm - h Stunde - kg Kilogramm - l/d Liter pro Tag - MAP Mittlerer arterieller Blutdruck - mg Milligramm - mg/d Milligramm pro Tag - ml/min Milliliter pro Minute - mmHg Millimeter Quecksilbersäule (Torr) - mmol/d Millimol pro Tag - NaCl Natriumchlorid - ng/ml/h Nanogramm pro Milliliter und Stunde - PA Plasma-Aldosteron - pg/ml Picogramm pro Milliliter - PRA Plasma-Renin-Aktivität - RAAS Renin-Angiotensin-Aldosteron-System - SEM Standardfehler des Mittelwertes - SKrea Kreatininkonzentration im Serum - SOsm Serum-Osmolalität - UKrea Kreatininkonzentration im Urin - UOsm Urin-Osmolalität - V Urinminutenvolumen - vgl. vergleiche - µmol/l Micromol pro Liter 相似文献
54.
慢性乙型肝炎患者血清HBV DNA水平与肝纤维化标志物的关系 总被引:1,自引:0,他引:1
目的研究慢性乙型肝炎患者血清HBV复制水平和肝纤维化血清学标志物的关系。方法入选临床确诊为慢性乙型肝炎的157例患者,其中49例为早期肝硬化,采用荧光定量PCR检测血清HBVDNA水平,放射免疫法和酶免疫法检测肝纤维化血清标志物:透明质酸、层黏蛋白、Ⅲ型前胶原N端肽和Ⅳ型胶原,对血清HBVDNA水平和肝纤维化标志物的关系进行研究分析,并对49例早期肝硬化患者和108例无肝硬化患者的血清HBVDNA及肝纤维化血清标志物水平进行比较。结果慢性乙型肝炎患者的血清HBVDNA水平和肝纤维化标志物水平无显著相关性(P〉0.05),早期肝硬化患者的血清肝纤维化标志物水平显著高于无肝硬化的患者,而HBVDNA水平却低于无肝硬化的患者(P〈0.05)。结论慢性乙型肝炎患者的血清HBVDNA水平和肝纤维化标志物水平无显著相关性。 相似文献
55.
Primary biliary cirrhosis and coronary atherosclerosis: Protective antioxidant effect of bilirubin 总被引:1,自引:0,他引:1
L. B. Dudnik O. A. Azyzova N. P. Solovyova A. P. Savchenkova M. A. Pokrovskaya 《Bulletin of experimental biology and medicine》2008,145(1):18-22
Increased concentration of lipid peroxidation products in patients with primary biliary cirrhosis is related to elevation
of serum lipid content, but not to activation of lipid peroxidation. Hyperbilirubinemia in patients with primary biliary cirrhosis
is accompanied by a decrease in the concentration of lipid peroxidation products and increase in antioxidant activity of blood
serum. Antioxidants play a major role in the prevention of atherosclerosis. We hypothesized that the absence of increased
risk of atherosclerosis in patients with primary biliary cirrhosis is due to inhibition of lipid peroxidation in blood serum
by antioxidant compound bilirubin.
__________
Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 23–28, January, 2008 相似文献
56.
p53 immunoreactivity in hepatocellular adenoma, focal nodular hyperplasia, cirrhosis and hepatocellular carcinoma 总被引:2,自引:0,他引:2
I. OJANGUREN A. ARIZA E.M. CASTELLÀ A. FERNÁNDEZ-VASALO J.L. MATE J.J. NA VAS-PALACIOS 《Histopathology》1995,26(1):63-68
The prolonged half-life of mutant p53 makes feasible its immunocytochemical detection. In order to assess the pathogenetic role of mutant p53 in regenerative and neoplastc liver disease we studied its immunohistochemical expression in cases of hepatic cirrhosis, hepatocellular carcinoma (HCC), cirrhosis with areas of HCC, hepatocellular adenoma and focal nodular hyperplasia. The study included needle and wedge biopsies of 50 cirrhotic livers, 59 HCCs (36 of them with associated cirrhosis), six adenomas and two focal nodular hyperplasias. Sixty-five HCC fineneedle cytology specimens were also included in the study. There was no immunohistochemical evidence of mutant p53 expression in any of the cases of cirrhotic liver (except for one instance associated with HCC) adenoma or focal nodular hyperplasia. In contrast p53 was detected in 8.5% of HCC cases in the biopsy series and 24% of HCC cases in the fine needle aspiration series. In addition, mutant p53 expression in HCC was positively correlated with tumour grade. According to grade, the distribution of p53 positive immunoreactivity among HCCs was as follows: Grade I-II, 0% of cases in the biopsy series and 9% in the fine needle aspirates; Grade III, 18% in the biopsy series and 55% in the fine needle aspirates; and Grade IV, 40% in the biopsy series. Therefore, mutant p53 expression does not seem to be associated with benign liver lesions but seems to correlate with the progression of HCC through various grades of increasing malignancy. 相似文献
57.
The pathogenesis of progressive bile duct loss in primary biliary cirrhosis remains unclear. In this study, the involvement of cellular senescence of biliary epithelial cells was examined in liver tissue samples from patients with primary biliary cirrhosis (n = 33), and compared with control diseased and normal livers (n = 83). In addition, cellular senescence was induced by oxidative stress in cultured mouse biliary epithelial cells. Biliary epithelial cells in small bile ducts in primary biliary cirrhosis, especially those in patients presenting with chronic non-suppurative cholangitis, frequently expressed senescence-associated beta-galactosidase, and senescence-associated p16(INK4) and p21(WAF1/CIP). In contrast, senescence-associated markers were rarely expressed in small bile ducts in control livers. The infiltration of myeloperoxidase-positive inflammatory cells into biliary epithelial cell layers was closely associated with the cellular senescence of biliary epithelial cells in early-stage PBC. Cellular senescence of cultured mouse biliary epithelial cells was induced by treatment with H2O2 via the p38MAPK-dependent pathway and nitric oxide-augmented H2O2-induced cellular senescence. Oxidative stress- and nitric oxide-mediated cellular senescence may be involved in bile duct lesions, which are followed by progressive bile duct loss in primary biliary cirrhosis. 相似文献
58.
为阐明肝硬化时TXA_2/PGI_2的代谢状况及其与门脉高压的关系,我们研究了慢性胆管结扎犬肝硬化时血浆TXB_2/6-keto-PGF_(1α)变化及其与门脉血液动力学的关系。结果表明,肝硬化犬下腔静脉TXB_2水平与正常犬相近(P>0.05),肝静脉显著高于正常犬(P相似文献
59.
Alena Jiroutova Rastislav Slavkovsky Martina Cermakova Lenka Majdiakova Irena Hanovcova Radka Bolehovska Milena Hajzlerova Hana Radilova Ema Ruszova Jiri Kanta 《Experimental and toxicologic pathology》2007,58(4):263-273
Hepatic stellate cells (HSC) and liver myofibroblasts (MFB) are two cell populations most likely responsible for the synthesis of most connective tissue components in fibrotic liver. They differ in their origin and location, and possibly in patterns of gene expression. Normal and carbon tetrachloride-cirrhotic livers from rats were used to isolate HSC. Liver was perfused with pronase and collagenase solutions, followed by centrifugation of the cell suspension on a density gradient. HSC were quiescent 2 days after plating on plastic but they became activated after another 5 days in culture. When the culture was passaged 5 times, its character changed profoundly as HSC were replaced by MFB. Microarray analysis was used to determine gene expression in quiescent HSC, activated HSC and MFB. The expression of 49 genes coding for connective tissue proteins, proteoglycans, metalloproteinases and their inhibitors, growth factors and cellular markers was determined. The pattern of gene expression changed during HSC activation and there were distinct differences between HSC and MFB. Little difference between normal cells and cells isolated from cirrhotic liver was found. 相似文献
60.
Selmi C Ichiki Y Invernizzi P Podda M Gershwin ME 《Clinical reviews in allergy & immunology》2005,28(2):73-81
Primary biliary cirrhosis (PBC) is a chronic cholestatic disease characterized by a striking predominance in female patients
(with most cases diagnosed between ages 40 and 60 yr) as well as serum auto-antibodies to mitochondrial antigens, elevated
serum immunoglobulin M, progressive destruction of intrahepatic bile ducts, and, ultimately, liver cirrhosis and failure (1). The precise mechanisms leading to selective destruction of biliary epithelial cells lining intrahepatic bile ducts are
still unknown, although numerous immunomediated pathways have been proposed. Genetic background appears to be important in
determining susceptibility to the disease (2), but no clear association with alleles in the major histocompatibility complex has been identified. Molecular mimicry either
by infections (3) or xenobiotics (4) has been proposed to be capable of breaking tolerance in genetically predisposed individuals, thus leading to onset of PBC.
This article describes and discusses the available data regarding the immunomediated pathogenesis of PBC (with particular
attention to auto-antibodies and autoreactive T-cells) and presents the recent evidence indicating a role for either xenobiotic
chemicals or novel infectious agents in the induction of the disease. 相似文献