全文获取类型
收费全文 | 4777篇 |
免费 | 457篇 |
国内免费 | 130篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 64篇 |
妇产科学 | 94篇 |
基础医学 | 539篇 |
口腔科学 | 250篇 |
临床医学 | 515篇 |
内科学 | 477篇 |
皮肤病学 | 53篇 |
神经病学 | 228篇 |
特种医学 | 255篇 |
外科学 | 748篇 |
综合类 | 583篇 |
预防医学 | 334篇 |
眼科学 | 148篇 |
药学 | 602篇 |
3篇 | |
中国医学 | 230篇 |
肿瘤学 | 187篇 |
出版年
2024年 | 13篇 |
2023年 | 117篇 |
2022年 | 188篇 |
2021年 | 344篇 |
2020年 | 248篇 |
2019年 | 210篇 |
2018年 | 224篇 |
2017年 | 240篇 |
2016年 | 191篇 |
2015年 | 206篇 |
2014年 | 372篇 |
2013年 | 328篇 |
2012年 | 252篇 |
2011年 | 265篇 |
2010年 | 202篇 |
2009年 | 184篇 |
2008年 | 183篇 |
2007年 | 191篇 |
2006年 | 161篇 |
2005年 | 128篇 |
2004年 | 91篇 |
2003年 | 87篇 |
2002年 | 87篇 |
2001年 | 60篇 |
2000年 | 75篇 |
1999年 | 60篇 |
1998年 | 59篇 |
1997年 | 52篇 |
1996年 | 57篇 |
1995年 | 49篇 |
1994年 | 43篇 |
1993年 | 35篇 |
1992年 | 40篇 |
1991年 | 22篇 |
1990年 | 27篇 |
1989年 | 27篇 |
1988年 | 26篇 |
1987年 | 29篇 |
1986年 | 27篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 8篇 |
1982年 | 21篇 |
1981年 | 23篇 |
1980年 | 12篇 |
1979年 | 19篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1973年 | 5篇 |
排序方式: 共有5364条查询结果,搜索用时 31 毫秒
51.
目的 探究水-醇双提工艺下中药复方粉末影响颗粒流动性的关键物性参数。方法 以水-醇双提工艺下杏贝止咳颗粒(Xingbei Zhike Keli,XZK)、桂枝茯苓胶囊(Guizhi Fuling Jiaonang,GFJ)以及参乌益肾片(Shenwu Yishen Pian,SYP)3个中药复方品种的制粒前粉末与制粒后颗粒为研究对象,采用多元统计分析方法,绘制粉末物理指纹图谱,结合Pearson相关系数评价粉末质量一致性;采用主成分分析(principal component analysis,PCA)结合因子分析评价颗粒流动性;并构建以松装密度(Da)、振实密度(Dc)、休止角(α)、豪斯纳比(IH)、粒径<50μm百分比(Pf)、均匀性(HG)、均齐度(UN)、粒径(D10、D50、D60、D90)、分布宽度(span)、分布范围(width)、比表面积(SSA)、孔隙率(Ie)、卡尔指数(IC)、含水量(HR)、吸湿率(H... 相似文献
52.
目的:探讨脊柱-骨盆矢状位参数及关节突关节角度对退变性腰椎滑脱的影响及相关性研究。方法:以2016年7月至2019年9月确诊的120例L4-L5单节段退变性滑脱患者为观察对象(滑脱组),以性别和年龄相匹配的120例L4-L5节段退变性椎管狭窄患者为对照(对照组)。通过影像学资料测量如下参数:骨盆入射角(pelvic incidence,PI),骨盆倾斜角(pelvic tilt,PT),骶骨倾斜角(sacral slope,SS),腰椎前凸(lumbar lordosis,LL),胸椎后凸(thoracic kyphosis,TK),矢状面平衡(sagittal vertical axis,SVA),L4-L5头侧关节突关节角,尾侧关节突关节角及小关节不对称性。比较两组患者参数的差异并对有意义参数行Logistic回归分析。对退变性腰椎滑脱患者关节突关节方向与脊柱-骨盆参数进行相关性分析。结果:两组患者在PI、PT、LL、SVA、头侧关节突关节角、尾侧关节突关节角差异有统计学意义(P<0.05);Logistic回归分析发现PI、PT及头侧关节突关节角是腰椎滑脱程度的危险因素(P<0.05)。滑脱组头侧关节突关节矢状化与PI、PT呈现显著相关(P<0.05)。结论:高PI、PT及头侧关节突关节矢状化是腰椎滑脱的危险因素,并且关节突关节矢状化程度和大PI、PT密切相关。 相似文献
53.
54.
目的:研究髌骨矢状面截骨术对髌骨倾斜病理应力分布的影响。方法:采用手术方法将七具新鲜人尸体膝关节标本的髌骨外侧支持带紧缩,造成髌骨过度外侧倾斜,然后进行四个不同截骨角的髌骨矢状面截骨术。股四头肌腱加载200N。分别于正常状态、髌骨倾斜、截骨5°、10°、15°、20°六种工况下,应用压敏片测量髌股关节接触压力与面积。摄屈膝45°Merchant髌骨轴位片,测量髌骨倾斜角,了解髌骨倾斜程度。结果与结论:髌骨倾斜后,髌骨内侧接触面积与压力均减少,外例接触面积与压力均增加,屈膝30°时最显著。截骨10°以上,明显改善了髌骨倾斜的应力分布,其中截骨15°改善较为理想。本实验结果为临床上髌骨矢状面截骨术中截骨角的选择提供了可靠依据。 相似文献
55.
Mental Health of Mothers of Children with Juvenile Rheumatoid Arthritis: Appraisal as a Mediator 总被引:1,自引:3,他引:1
Lustig Julie L.; Ireys Henry T.; Sills Edward M.; Walsh Beverly B. 《Journal of pediatric psychology》1996,21(5):719-733
Examined direct and mediated relations between condition parametersand maternal mental health for 53 mothers of 2- to 11-year-oldchildren with juvenile rheumatoid arthritis (JRA). Multivariateanalyses revealed that when considered simultaneously, indicesof both biological severity and functional severity were associatedsignificantly with maternal mental health. Further, mother'sappraisals of the impact of the child's illness on the familypartially mediated the effects of medication type and child'sfunctional status on mother's mental health. Results providesupport for conceptual models that emphasize the cognitive mechanismsby which condition parameters such as biological and functionalseverity might affect maternal mental health. Explicating theprocesses by which a child's JRA might lead to psychologicaladjustment problems in the parent has implications for developingpreventive and treatment interventions. 相似文献
56.
计算机嗓音测试参数的特点及临床意义 总被引:5,自引:0,他引:5
电子计算机嗓音测试及频谱分析已成为嗓音客观检查的重要手段。其测试参数为喉部疾病诊断、疗效评价的主要指标。但嗓音的声学参数是一种多维函数,与声带振动的生物力学密切相关。为了更好的理解和掌握嗓音的声学参数,对嗓音测试的参数进行详细的分析。以便于准确地选用和科学、客观地评价嗓音。 相似文献
57.
Yu. P. Denisov P. V. Sergeev N. P. Saksonov G. V. Shutko 《Bulletin of experimental biology and medicine》1980,89(2):147-150
Parameters of binding of cortisone and estradiol to plasma membranes of rat hepatocytes were studied by the method of liquid scintillation radiometry. The presence of two systems for the binding of these hormones in the membranes was demonstrated. One system is specific (saturable) and binds hormones in physiological concentrations. The capacity and affinity of this system for cortisone are significantly higher than for estradiol. The binding parameters within the temperature range from 4 to 37°C for cortisone and estradiol respectively are: Dissociation constant 2.1–3 and 2.7–4.5 nM, number of binding sites 2–2.4 and 0.14–0.18 nmoles/mg protein. Experiments with p-chloromercuribenzoate demonstrate the role of proteins in the working of this system. The second (unsaturable) system is nonspecific and its function is determined by the lipid component of the membranes. The affinity of corticosteroids for hepatocytes is probably due to the activity of the (saturable) specific system of the plasma membranes of these cells.Department of Molecular Pharmacology and Radiobiology, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 172–174, February, 1980. 相似文献
58.
The membrane properties of the neurons located in the ventral part of the periaqueductal grey (PAG) of the guinea-pig were studied using an in vitro slice preparation. Cells had low values of resting membrane potential (-53.3 +/- 1.3 mV, mean +/- standard error), high input resistance (195. +/- 16.2 M ohm) and moderate values of membrane time constant (12.6 +/- 0.7 ms). The last two parameters changed as recordings were made along the sagittal axis, higher values corresponding to the more rostral cells. Three main neuronal types-fusiform, triangular and stellate-were found in the ventral PAG using intracellular injection of Lucifer yellow. A study of the cell number and cell density was carried out in coronal and sagittal sections of the ventral PAG. This analysis showed a clear gradient of size in this region arising from the gradual disappearance of large (17 to 40 microm) neurons in the caudorostral direction. The neuronal density also increased in this direction. Therefore, some electrotonic and morphological parameters differ along the sagittal axis. These findings suggest a larger neuronal heterogeneity of the caudal part of the PAG, and might contribute to a functional segregation of this region. 相似文献
59.
Summary The study concerns the clinical outcome and later prognosis (regarding permanent insulin treatment) of patients who develop insulin-dependent diabetes mellitus during pregnancy (which is different from gestational diabetes). Sixty-three such patients (27±1 (SEM) years old) were delivered at the Copenhagen Centre for Diabetes and Pregnancy during the years 1966–1980. Obstetric complications such as toxaemia were seen in 9.5% of these study patients and the perinatal mortality was 6.3%, both percentages being higher than in the general population (1.1%,p<10–7 and 1.0%,p<10–3, respectively), but similar to those observed in patients with Type 1 diabetes diagnosed before pregnancy. In contrast, the frequency of malformations was 1.6%, the same as in the general population (1.4%), but lowerthan that seen in patients with long-standing diabetes (8.3%,p<0.05). At follow-up examination 8±1 years after diagnosis all patients were diabetic; 77% were insulin treated, having no or virtually no residual B-cell function, and were clearly Type 1 diabetic patients. After delivery 80% of the patients had a remission period (median 256 days) without insulin treatment. This remission period was absent or shortest in patients with the following characteristics (p0.03): low age, first parity, not overweight, and high blood glucose level at diagnosis. These prognostic parameters should be considered in obligatory, clinical follow-up plans for such patients. 相似文献
60.