全文获取类型
收费全文 | 788篇 |
免费 | 150篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 57篇 |
妇产科学 | 10篇 |
基础医学 | 103篇 |
口腔科学 | 21篇 |
临床医学 | 106篇 |
内科学 | 227篇 |
皮肤病学 | 19篇 |
神经病学 | 39篇 |
特种医学 | 171篇 |
外科学 | 60篇 |
综合类 | 20篇 |
预防医学 | 37篇 |
眼科学 | 12篇 |
药学 | 51篇 |
肿瘤学 | 37篇 |
出版年
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 12篇 |
2013年 | 18篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 37篇 |
2009年 | 38篇 |
2008年 | 15篇 |
2007年 | 35篇 |
2006年 | 13篇 |
2005年 | 22篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 16篇 |
1998年 | 53篇 |
1997年 | 54篇 |
1996年 | 47篇 |
1995年 | 55篇 |
1994年 | 51篇 |
1993年 | 35篇 |
1992年 | 14篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 33篇 |
1988年 | 38篇 |
1987年 | 29篇 |
1986年 | 22篇 |
1985年 | 21篇 |
1984年 | 17篇 |
1983年 | 16篇 |
1982年 | 20篇 |
1981年 | 14篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 12篇 |
1977年 | 15篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1970年 | 3篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有975条查询结果,搜索用时 15 毫秒
91.
92.
Background
Mental health problems have become more common among young people over the last twenty years, especially in certain countries. The reasons for this have remained unclear. The hypothesis tested in this study is that national trends in young people's mental health are associated with national trends in young people's labour market. 相似文献93.
目的 探讨前列腺癌 (PC)治疗前体外照射诱导的Go淋巴细胞微核量是否与放疗 (xRT)相关疾病的发生有关。方法 对 3 8例PC周围血淋巴细胞 (PBL)以细胞因子阻止的微核法进行前瞻性观察。患者平均年龄 68.7± 1.0岁。临床分期 :T116例 ,T2 16例 ,T36例。治疗前前列腺癌特异性抗原 (PSA)≤ 4ng·ml-1者 5例 ,4~ 10ng·ml-1者 19例 ,>10ng·ml-1者 14例。所有患者均接受标准的骨盆外xRT(41.4~ 5 0 .4Gy) ,追加剂量 (16.4~ 2 6Gy)。平均随访 3 2 .8± 4.6个月。随访末 ,按RTOG标准对胃肠道 (GI)或泌尿生殖道 (GU)xRT相关疾病的发生率进行评定。结果 发生xRT相关疾病 2 4例为高敏 (HS) ,未发生者 14例为正常敏感性 (NS) ,HS患者均有GI(1~ 3级 )或GU(1~ 2级 )xRT相关疾病。体外照射暴露的血标本 ,与照射剂量相关的PBL微核量在HS和NS患者之间有显著差异 ,特别是当剂量≥ 3Gy时。xRT相关疾病的发生与治疗前PBL微核量相关 ,而与病情无关。结论 与xRT前体外照射剂量相关的PBL微核量是骨盆xRT的PC患者GI或GU疾病发生的一个预示因素 相似文献
94.
95.
96.
Little is known of the influence race has on the development of leg ulceration, with most studies being performed in almost exclusively white populations. As part of a wider audit of leg ulcer services, health care professionals were contacted to give details of age, sex and ethnic background of all patients who attended for treatment of leg ulceration over a one year period in an area of west London. West London Health Care Trust provides services to a population of 275000 of whom 53000 have an ethnic background from the Indian subcontinent (South Asian).In all, 280 patients were identified, of whom 264 (94%) had details of age and sex. This gave a crude ascertainment rate of 1.02 per 1000 population. Of the 264 patients, five were classified as South Asians, with one patient classified as Afro-caribbean. The Mantel Haenzsel test demonstrated a significantly higher proportion of whites suffering from leg ulceration than South Asians, giving an odds ratio of 4.43, with 95% confidence intervals between 1.94 and 10.13 (P=0.0004). The expected frequency of South Asian patients should be 23, based on rates from the white population, of which 13 would be women and 10 men. Only five South Asian men were identified, and no Asian women with leg ulceration.Reasons for this low ascertainment are two-fold. Either there is a real difference between the white and South Asian populations, or South Asian patients are not presenting for treatment. Further work must be performed to determine whether this is an effect of low prevalence, or unmet need in the community. 相似文献
97.
98.
99.
Leeksma OC; Meijer-Huizinga F; Stoepman-van Dalen EA; van Ginkel CJ; van Aken WG; van Mourik JA 《Blood》1986,67(5):1460-1467
Concentrations of plasma fibrinopeptide A (FPA) were measured by radioimmunoassay in 50 patients with venous thromboembolism or disseminated intravascular coagulation or both. A consistent discrepancy was observed in values obtained with two anti-FPA antisera. Analysis of extracts from plasma of these patients by high-performance liquid chromatography (HPLC) revealed the presence of a phosphorylated and an unphosphorylated form of the A peptide. Differences in concentrations of FPA measured with the two antisera could be accounted for by their different reactivity with phosphorylated FPA (FPA-P). The differences were abolished by treatment with alkaline phosphatase. A good correlation was observed between the FPA-P content of free A- peptide material and of fibrinogen in plasma as determined by HPLC (r = .88, P less than .001, n = 11). In patients with elevated FPA levels, the mean FPA-P content of fibrinogen was significantly higher (P less than .002, n = 13) than in patients with normal FPA levels (n = 8) and in healthy controls (n = 14). Phosphorus in fibrinogen did not correlate with fibrinogen degradation products or fibrinogen levels and became normal on adequate anticoagulation. Therefore, blood-clotting activation may lead to a high phosphate content of fibrinogen and of free FPA in plasma. 相似文献
100.