全文获取类型
收费全文 | 4810篇 |
免费 | 321篇 |
国内免费 | 177篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 148篇 |
妇产科学 | 15篇 |
基础医学 | 499篇 |
口腔科学 | 29篇 |
临床医学 | 433篇 |
内科学 | 740篇 |
皮肤病学 | 69篇 |
神经病学 | 112篇 |
特种医学 | 98篇 |
外科学 | 195篇 |
综合类 | 749篇 |
现状与发展 | 1篇 |
预防医学 | 271篇 |
眼科学 | 138篇 |
药学 | 1197篇 |
6篇 | |
中国医学 | 544篇 |
肿瘤学 | 47篇 |
出版年
2024年 | 14篇 |
2023年 | 45篇 |
2022年 | 104篇 |
2021年 | 137篇 |
2020年 | 134篇 |
2019年 | 118篇 |
2018年 | 122篇 |
2017年 | 106篇 |
2016年 | 162篇 |
2015年 | 145篇 |
2014年 | 256篇 |
2013年 | 319篇 |
2012年 | 273篇 |
2011年 | 257篇 |
2010年 | 230篇 |
2009年 | 198篇 |
2008年 | 217篇 |
2007年 | 256篇 |
2006年 | 246篇 |
2005年 | 233篇 |
2004年 | 185篇 |
2003年 | 179篇 |
2002年 | 163篇 |
2001年 | 143篇 |
2000年 | 140篇 |
1999年 | 123篇 |
1998年 | 86篇 |
1997年 | 91篇 |
1996年 | 55篇 |
1995年 | 64篇 |
1994年 | 33篇 |
1993年 | 52篇 |
1992年 | 50篇 |
1991年 | 40篇 |
1990年 | 46篇 |
1989年 | 33篇 |
1988年 | 28篇 |
1987年 | 29篇 |
1986年 | 18篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 12篇 |
1982年 | 21篇 |
1981年 | 15篇 |
1980年 | 13篇 |
1979年 | 9篇 |
1978年 | 15篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1974年 | 8篇 |
排序方式: 共有5308条查询结果,搜索用时 15 毫秒
41.
Rogers DF 《Inflammopharmacology》1997,5(4):319-329
Neurogenic inflammation results from activation of sensory nerves which, acting in an ‘efferent’ manner, release sensory neuropeptides
to induce a wide variety of physiological and immunological responses. This process is easy to demonstrate experimentally
in the airways of small laboratory animal species but in human airways is equivocal and, at best, minor compared with cholinergic
neural control. Nevertheless, sensory neuropeptides (calcitonin gene-related peptide and the tachykinins, substance P and
neurokinin A) induce airway responses in both laboratory animals and humans which suggest a potential for sensory-efferent
control of human airways. In addition, there is indirect evidence for an increased ‘expression’ of sensory nerves and tachykinin
receptors in asthma and bronchitis, which indicates that neurogenic inflammation contributes to pathophysiology of these airway
conditions. In contrast, clinical trials using different classes of drugs to inhibit sensory nerve responses have failed to
resolve whether neurogenic inflammation is involved in asthma, although there are concerns about the relevance of some of
these studies. In contrast to their involvement in airway neurogenic inflammation, sensory nerves may be important in initiating
protective reflexes, including coughing and sneezing, acting via their afferent pathways. Thus, although flickering, the concept
of neurogenic inflammation in lung disease is not yet burnt out. However, it needs the rekindling of interest which re-evaluation
as a protective process may bring, together with data from more appropriate clinical studies in asthma and chronic bronchitis. 相似文献
42.
It has been suggested that albumin reduces quinidine capillary permeability (PS) in the single-pass perfused heart preparation by reducing paracellular transport of quinidine ions. Using this preparation, we examined the effect of albumin (0.1 per cent) on quinidine PS at perfusate pHs of 7.1 and 7.9 during uptake of quinidine (19 µM) and also during washout of the drug using a randomized design. Quinidine PS was approximately 16 ml/min/g heart at pH 7.9 and was not altered by the presence of albumin in perfusate. At pH 7.1, in the absence of albumin, quinidine PS was also 16 ml/min/g, but in the presence of albumin (0.1 per cent) PS was reduced significantly to approximately 5 ml/min/g (P < 0.001). In the absence of albumin PS was the same at pH 7.1 and 7.9 in spite of a greater degree of ionisation of quinidine at pH 7.1. This suggests that there is significant uptake of ionised quinidine at pH 7.1. The greater effect of albumin on PS at pH 7.1 supports the hypothesis that albumin reduces paracellular transport of quinidine ions. 相似文献
43.
目的用毛细管电泳中的胶束动电法直接测定血清尿酸浓度。方法以SDS作为电泳缓冲液中和胶束相,采用非涂渍毛细管21cm×50μm(i.d.),检测波长235nm,以外标法定量。结果尿酸测定的线性范围为46.5~1500μmol/L,最低检测限为20.31μmol/L:本法的日内和日间变异系数均小于4.5%;平均回收率为101.45%。内生性化合物和临床某些常用药物对此方法无干扰。结论该法线性范围宽,简单、快速,可应用于临床样品检测。 相似文献
44.
sIL—4和细胞间粘附分子及总IgE在呼吸道炎症中的表达 总被引:1,自引:0,他引:1
目的探讨可溶性白细胞介素-4(solubleinterleukin-4,sIL-4)、细胞间粘附分子-1(in-tercellaradhesionmolecule-1,ICAM-1)在过敏性鼻炎(allergicrhinitis,AR)、咳嗽变异性哮喘(coughvariableasthma,CVA)、哮喘和慢性支气管炎发病中的作用。方法采用酶标法测定12例AR、21例CVA、29例哮喘缓解期、27例哮喘发作期、11例慢性支气管炎患者和10例正常健康人血标本。结果(1)sIL-4:CVA、哮喘发作期和慢支组高于正常组(P<0.05)。AR、哮喘缓解期与正常组比较无显著性差异。(2)ICAM-1:各组均高于正常组(P<0.05)。哮喘发作组又高于AR组和哮喘缓解组(P<0.05)。(3)总IgE:除慢支组外其余各组均高于正常组(P<0.05)。结论sIL-4、ICAM-1参与气道炎症的形成过程,且其含量的高低与咳嗽的发生呈平行发展关系。 相似文献
45.
We measured IgG antibody levels against eight different microbes in farmer's lung (FL) patients an average of 14 years after the first diagnosed episode of FL and in matched controls. The study population consisted of 87 FL patients and 81 control farmers, matched by age, sex, and smoking habits. Clinical studies included the measurement of IgG antibody levels against Absidia corymbifera, Aspergillus umbrosus, A. fumigatus, Humicola grisea, Saccharopolyspora rectivirgula, Penicillium brevicompactum, Rhodotorula glutinis, and Thermoactinomyces vulgaris, in addition to spirometry, pulmonary diffusing capacity (DL(CO)), and the evaluation of chronic bronchitis. Median IgG antibody levels were two or more times higher in FL patients than control farmers against Ab. corymbifera, S. rectivirgula, and T. vulgaris (P<0.001). Against A. fumigatus, H. grisea, and R. glutinis, FL patients also had significantly higher antibody levels. FL patients often had positive antibody titers against several microbes, whereas control farmers usually had a positive titer against one or two microbes. A positive association between IgG antibody levels and chronic bronchitis and DL(CO) was observed in FL patients, but not in control farmers. It is suggested that the high antibody levels noted in FL patients were due not only to high exposure but also to individual sensitivity to environmental microbes. 相似文献
46.
血糖监测仪测定微血管全血糖的临床研究 总被引:5,自引:0,他引:5
目的:研究血糖仪测定微血管全血糖与生化法测定静脉血清糖之间的差别以及相关性,验证血糖仪的准确性及稳定性。方法:用ONETOUCHⅡ血糖仪测定微血管全血糖(CBG)337 例(全部为2 型糖尿病患者),同时用葡萄糖氧化酶法测定静脉血清糖(VSG)。结果:VSG 高于CBG10.8% ,VSG 与CBG 之间存在显著相关性,r 为0.95,P< 0.001。结论:轻便血糖监测仪测CBG快速,简便,对操作者技术要求不高,适用于糖尿病人血糖自我监测和糖尿病筛选、普查 相似文献
47.
Summary In a double-blind, placebo-controlled, incomplete cross-over study the bronchodilator, cardiovascular, respiratory and metabolic effects of 3 different oral doses of clenbuterol were studied in 12 patients suffering from partly reversible airways obstruction due to chronic bronchitis. The ventilatory response to oral clenbuterol or placebo was assessed by measurement of specific airway resistance (sRaw) to detect changes in central airways, and of flow at 85% of vital capacity (
85% VC) to detect change in peripheral airways. Clenbuterol 20, 30 and 40 µg produced a significant decrease in sRaw between 15 and 480 min after administration. Its effect on the large airways was not related to the dose. Clenbuterol 30 and 40 µg caused a significant increase in
85% VC between 60 and 480 min after administration. After 20 µg a significant improvement in
85% VC was found between 120 and 240 min. The over-all effect of 30 µg on the small airways was significantly more pronounced than that of 20 µg and was more sustained than that of 40 µg 120 min after administration. No significant changes in heart rate, ECG or blood pressure were noted. Decreases in PaO2 and O2-saturation after clenbuterol were not related to dose. Slight falls in PaO2 and O2-saturation were also observed after placebo. These observations are briefly discussed. There was negligible lipid mobilization after either the placebo or bronchodilator. A slight but insignificant rise in blood glucose was observed after both 30 and 40 µg of clenbuterol. 相似文献
48.
Summary In 20 patients with an acute exacerbation of chronic respiratory tract infection the effectiveness of oral erythromicin succinate 3×500 mg daily has been tested. The duration of treatment was 10 days in all cases. The criteria of success, in addition to the clinical findings, were the results of bacteriological investigations and assessment of the appearance of the sputum. In all patients sputum and serum concentrations or erythromicin were determined. All pathogens isolated from the sputum of the patients were erythromicin-sensitive. One instance of development of resistance was observed. The drug was well tolerated. 相似文献
49.
50.
麻黄中生物碱类有效成分的非水毛细管电泳含量测定 总被引:9,自引:1,他引:9
目的 利用非水毛细管电泳(NACE)法对麻黄中各生物碱类有效成分进行含量测定,并比较不同提取方法中各组份含量差异。方法 采用50mmol/L醋酸铵的甲醇溶液,未加入任何其他添加剂,检测波长为210nm。结果 各组份在8min内达基线分离。伪麻黄碱在9.8~147.0μg/mL,去甲基麻黄碱在6.8~102.0μg/mL,麻黄碱在9.4~141.0μg/mL,去甲基伪麻黄碱在4.8~72.0μg/mL,甲基麻黄碱在6.8~102.0μg/mL分别有良好的线性关系。各麻黄碱类回收率在95.0%~100.4%。结论 为麻黄中各生物碱类有效成分的含量测定提供了一种快速、准确和灵敏的测定方法。 相似文献