全文获取类型
收费全文 | 24394篇 |
免费 | 1541篇 |
国内免费 | 565篇 |
专业分类
耳鼻咽喉 | 105篇 |
儿科学 | 430篇 |
妇产科学 | 309篇 |
基础医学 | 5898篇 |
口腔科学 | 453篇 |
临床医学 | 1333篇 |
内科学 | 3096篇 |
皮肤病学 | 539篇 |
神经病学 | 1364篇 |
特种医学 | 525篇 |
外国民族医学 | 4篇 |
外科学 | 1918篇 |
综合类 | 3399篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 921篇 |
眼科学 | 195篇 |
药学 | 2956篇 |
7篇 | |
中国医学 | 1475篇 |
肿瘤学 | 1571篇 |
出版年
2024年 | 53篇 |
2023年 | 306篇 |
2022年 | 414篇 |
2021年 | 744篇 |
2020年 | 787篇 |
2019年 | 692篇 |
2018年 | 627篇 |
2017年 | 736篇 |
2016年 | 728篇 |
2015年 | 785篇 |
2014年 | 1433篇 |
2013年 | 1751篇 |
2012年 | 1414篇 |
2011年 | 1745篇 |
2010年 | 1400篇 |
2009年 | 1487篇 |
2008年 | 1347篇 |
2007年 | 1265篇 |
2006年 | 1195篇 |
2005年 | 975篇 |
2004年 | 882篇 |
2003年 | 778篇 |
2002年 | 618篇 |
2001年 | 460篇 |
2000年 | 468篇 |
1999年 | 383篇 |
1998年 | 417篇 |
1997年 | 321篇 |
1996年 | 392篇 |
1995年 | 303篇 |
1994年 | 283篇 |
1993年 | 210篇 |
1992年 | 190篇 |
1991年 | 124篇 |
1990年 | 72篇 |
1989年 | 60篇 |
1988年 | 35篇 |
1987年 | 20篇 |
1986年 | 31篇 |
1985年 | 90篇 |
1984年 | 81篇 |
1983年 | 47篇 |
1982年 | 67篇 |
1981年 | 43篇 |
1980年 | 44篇 |
1979年 | 35篇 |
1978年 | 35篇 |
1977年 | 23篇 |
1976年 | 33篇 |
1975年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
胃癌患者红细胞免疫功能的变化 总被引:4,自引:1,他引:3
运用简单形态学方法测定了30例胃癌患者红细胞免疫功能,结果表明:胃癌患者红细胞C3b受体花环率及肿瘤红细胞花环率显著低于正常对照(P<0.01)及慢性良性胃病患者(P<0.01),而免疫复合物花环率则高于正常人(P<0.01)及慢性良性胃病患者(P<0.01);Ⅲ、Ⅳ期胃癌患者肿瘤红细胞复合物花环率明于低于Ⅰ、Ⅱ期患者(P<0.01);贲门癌肿瘤红细胞花环率显著低于胃窦(体)癌患者(P<0.01) 相似文献
92.
本文观察16例大肠癌病人的癌组织培养上清液对人T细胞的增殖,ZL—2产生的影响和病理Dukes分期的关系,发现癌组织的TDSF对T细胞的增殖有显著抑制作用,对ZL—2的产生抑制作用不明显,对T细胞增殖率在DukesA与B期,其值与对照有显著差异(0.01P<0.05).在C期有非常显著差异(P<0.01).说明大肠癌组织确实分泌有能造成宿主免疫功能下降的抑制物质.且免疫作用不是通过ZL—2环节发生. 相似文献
93.
P. H. Mogensen L. Jórgensen J. Boas M. Dam A. Vesterager G. Flesch P. K. Jensen 《Acta neurologica Scandinavica》1992,85(1):14-17
The effects of dextropropoxyphene on the steady-state kinetics of oxcarbazepine and its metabolites were investigated in eight patients with epilepsy or trigeminal neuralgia. One patient dropped out of the study, presumably due to side-effects of dextropropoxyphene. Dextropropoxyphene did not affect the plasma levels of the principal active metabolite, 10,11-dihydro-10-hydroxy-carbamazepine. Since dextropropoxyphene is known to increase the plasma levels of carbamazepine, leading to toxicity, the findings of this study suggest that oxcarbazepine is a useful alternative to carbamazepine when concomitant dextropropoxyphene therapy is required. 相似文献
94.
哮喘模型豚鼠变态反应机制的实验研究 总被引:6,自引:0,他引:6
张全爱 《甘肃中医学院学报》2003,20(4):16-17
目的 :观察哮喘豚鼠的变态反应机制是否与人体一致。方法 :健康豚鼠 2 4只 ,随机分为空白组、模型组、药物内服组。以血清总IgE、IgG、IL - 4为效应指标 ,观察 3组动物效应指标的变化。 结果 :各组动物血清总IgE水平没有发生显著性变化 ,模型组与空白组比较 ,IgG含量较空白组显著降低(P <0 .0 5 ) ,IL - 4含量显著升高 (P <0 .0 5 ) ,经药物治疗后 ,IgG含量明显增高 (P <0 .0 5 ) ,IL - 4含量则明显下降 (P <0 .0 5 )。结论 :豚鼠的哮喘是由IgG介导的变态反应 ,与人体哮喘由IgE介导的病理机制有所不同 ,建议实验应用豚鼠哮喘模型应当受到限制。 相似文献
95.
M. Silvestri M. Bontempelli M. Giacomelli M. Malerba G. A. Rossi A. Di Stefano A. Rossi F. L. M. Ricciardolo 《Clinical and experimental allergy》2006,36(11):1373-1381
BACKGROUND: Severe asthma is characterized by elevated levels of pro-inflammatory cytokines and neutrophilic inflammation in the airways. Blood cytokines, markers of 'systemic' inflammation, may be a feature of amplified inflammation in severe asthma. OBJECTIVE: To detect differences in IL-8, TNF-alpha, IL-16 and IL-13 levels in the serum(s) of stable severe and mild-moderate asthmatics related to blood leucocytes proportion, airway calibre and exhaled nitric oxide (NO) levels. METHODS: We assessed cytokine serum levels by ELISA and blood leucocyte counts by an alkaline peroxidase method in 20 healthy controls, 22 mild-moderate [forced expiratory volume in 1 s (FEV1)(%pred): 89+/-3] and 14 severe asthmatics [FEV1(%pred): 49+/-2]. RESULTS: IL-8 and TNF-alpha levels were higher in severe asthmatics than in mild-moderate asthmatics or in controls (P<0.05). No differences in IL-16 and IL-13 levels were detected. Severe asthmatics showed higher circulating neutrophil and eosinophil number than controls (P<0.05). In severe asthmatics, exhaled NO levels were superior than in controls (P<0.05), but inferior than in mild-moderate asthmatics (P<0.05). We found positive correlation between TNF-alpha levels and exhaled NO (r=0.67; P=0.01) or circulating neutrophil counts (r=0.57; P=0.03) in severe asthmatics. CONCLUSION: sTNF-alpha and sIL-8 are markers of 'systemic' inflammation in severe asthmatics, in conjunction with augmented circulating neutrophils, suggesting the involvement of neutrophil-derived cytokine pattern in severe asthma. 相似文献
96.
N. Hizawa M. Kawaguchi S.-K. Huang M. Nishimura 《Clinical and experimental allergy》2006,36(9):1109-1114
IL-17 family members belong to a distinct category of cytokines that coordinate local tissue inflammation by inducing the release of pro-inflammatory and neutrophil-mobilizing cytokines. The importance of the IL-17 family in inflammatory and autoimmune disease is becoming increasingly apparent. IL-17F is a recently discovered member of the IL-17 family that has a number of biological activities through induction of various cytokines, chemokines, and mediators. IL-17A, the founding member of the IL-17 family, and IL-17F are produced by several inflammatory cells, including activated T cells, in response to infectious and antigenic stimuli. Overexpression of IL-17A or IL-17F in the lungs results in induction of CXC chemokines and neutrophil recruitment. In a case-control study of 1125 unrelated Japanese subjects, a His161 to Arg161 (H161R) substitution in the third exon of the IL17F gene was shown to be associated with asthma and chronic obstructive pulmonary disease (COPD). Functionally, this variant failed to induce cytokines and chemokines, and interestingly, was able to antagonize the activity of wild-type IL-17F. These results provide an experimental basis for the observed genetic association with chronic inflammatory lung diseases, and also suggest the potential therapeutic utility of this antagonistic variant of IL-17F. Given that asthma and COPD are complex diseases involving a number of genetic and environmental factors, the genetic impact of IL-17F H161R with regard to the development of chronic airway inflammation likely varies among individuals with different genetic backgrounds and environmental exposures. 相似文献
97.
B. Ruiter V. Trégoat L. M''Rabet J. Garssen C. A. F. M. Bruijnzeel-Koomen E. F. Knol E. van Hoffen 《Clinical and experimental allergy》2006,36(3):303-310
BACKGROUND: One to two percent of infants suffer from IgE-mediated allergic reactions against cow's milk proteins. Most children develop clinical tolerance, but approximately 15% are still allergic by the age of 10 years. Little is known about the T cell epitopes in individual cow's milk protein in relation to allergy and tolerance. OBJECTIVE: To identify T cell epitopes in alphas1-casein, the most abundant milk protein, and to investigate T cell responses toward these epitopes in allergic, atopic and non-atopic children. METHODS: Allergen-specific T cell lines (TCLs) were derived from peripheral blood mononuclear cells of 11 cow's milk allergic, nine atopic and nine non-atopic children. T cell responses were measured to alphas1-casein and to overlapping peptides (18-mers), spanning the alphas1-casein molecule. Proliferation was determined by incorporation of (3)H-thymidine, and cytokine production (IL-10, IL-13 and IFN-gamma) was measured by ELISA. RESULTS: Four main regions (amino acid (AA) residues 43-66, 73-96, 91-114 and 127-180) in the alphas1-casein molecule were immunogenic to T cells, among which the AA residues 133-156 spanned the immunodominant part. Only subtle differences were found in peptide recognition between the subject groups. Some of the peptides induced slightly Th1- or Th2-skewed cytokine responses. The increased levels of IL-10 in response to alphas1-casein observed in TCLs from atopic children appeared not to be linked to recognition of specific IL-10-inducing epitopes. CONCLUSIONS: The immunodominant sequence in alphas1-casein is spanned by AA residues 133-156. Tolerance towards alphas1-casein in atopic children may be mediated by an overall induction of IL-10 and not by recognition of certain T cell epitopes. The identified T cell epitopes in children with cow's milk allergy may be useful targets in developing peptide immunotherapy. 相似文献
98.
E. Rigotti G. L. Piacentini M. Ress R. Pigozzi A. L. Boner D. G. Peroni 《Clinical and experimental allergy》2006,36(5):614-618
BACKGROUND: Precise relationship between breastfeeding and infant allergy is poorly understood. Objective Aim was to quantify TGF-beta(1) and IL-10 in colostrum and mature milk from allergic and non-allergic mothers and to verify relationship with allergic disease development. METHODS: Mothers (13 allergics, nine controls) of 22 newborns participated to prospective study on development of children atopy. Colostrum and mature milk were assayed for TGF-beta(1) and IL-10 by ELISA. Children underwent paediatrician evaluation at 6 months of life. RESULTS: Data are presented as median values and range. A significant difference in concentration of TGF-beta(1) between colostrum (330, range 0-3400 pg/mL) and mature milk (215, range 0-2400 pg/mL) was observed in samples from allergic mothers (P=0.015). In mature milk TGF-beta(1) was significantly lower in allergic (215, range 0-2400 pg/mL) than in non-allergic mothers (1059, range 0-6250 pg/mL) (P=0.015). IL-10 was weakly expressed without significant differences between allergic (4.8, range 0-42 and 9.5, range 0-42 pg/mL in colostrum and in mature milk) and non-allergic mothers (0, range 0-42 pg/mL in colostrum and 0, range 0-42 pg/mL in mature milk). After 6 months 46% infants from allergic mothers, but none from controls, presented atopic dermatitis. CONCLUSION: TGF-beta(1) was significantly less secreted in mature milk of allergic mothers, while no difference in IL-10 was found. Particular cytokine patterns in milk could influence development of atopic diseases. Further immunological studies in this field are necessary. 相似文献
99.
外阴尖锐湿疣人乳头瘤病毒感染的检测与分型 总被引:2,自引:0,他引:2
张秀华 《菏泽医学专科学校学报》2004,16(3):14-15
目的 了解患外阴尖锐湿疣人乳头瘤病毒(HPV)6型和11型的感染情况及PCR方法对尖锐湿疣诊断与分型的临床意义。方法 采用PCR方法测定160例尖锐湿疣患病题组织或分泌物中HPV6/11型及HPVl6/18型的感染率。结果 HPV6/11型感染率为95%(152/160),HPVl6/18型感染率为5%(8/160),HPV6/11型 HPVl6/18型混合感染率为1.3%(2/160)。结论 外阴尖锐湿疣患以HPV6型和11型感染为主。PCR方法是一种比较适合临床HPV检测与分型的极为敏感和特异的诊断方法。 相似文献
100.
SOICHIRO YOSHIDA KAZUAKI NAKAGOMI SHUICHI GOTO MASAMI FUTATSUBASHI TATSUO TORIZUKA 《International journal of urology》2006,13(6):829-831
Little work has been done with positive emission tomography (PET) in bladder tumors because high urinary excretion of (18)F-FDG makes visualization of the bladder tumor difficult. (11)C-choline has recently been reported as a new tracer which lacks urinary radioactivity. We report the result of (11)C-choline PET in four patients with invasive bladder tumors. In one case, (11)C-choline PET could detect bladder tumor effectively without urinary activity and bone metastasis despite negative bone scintigraphy. On the other hand, an intense accumulation of the tracer in the bladder hampered the interpretation on PET scanning in three patients. The mechanisms of the (11)C-choline accumulation in the bladder were reported to be due to inflammatory and proliferative changes in the mucosa of the bladder from previous catheterization or other factors. Further study is necessary to prove the value of (11)C-choline PET for detecting primary bladder cancer and bone metastasis. 相似文献