全文获取类型
收费全文 | 13913篇 |
免费 | 1356篇 |
国内免费 | 203篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 1101篇 |
妇产科学 | 948篇 |
基础医学 | 1306篇 |
口腔科学 | 318篇 |
临床医学 | 1197篇 |
内科学 | 1633篇 |
皮肤病学 | 194篇 |
神经病学 | 1195篇 |
特种医学 | 362篇 |
外国民族医学 | 2篇 |
外科学 | 1115篇 |
综合类 | 1652篇 |
一般理论 | 2篇 |
预防医学 | 1957篇 |
眼科学 | 628篇 |
药学 | 756篇 |
12篇 | |
中国医学 | 310篇 |
肿瘤学 | 682篇 |
出版年
2024年 | 17篇 |
2023年 | 195篇 |
2022年 | 272篇 |
2021年 | 583篇 |
2020年 | 553篇 |
2019年 | 559篇 |
2018年 | 491篇 |
2017年 | 580篇 |
2016年 | 581篇 |
2015年 | 499篇 |
2014年 | 873篇 |
2013年 | 1067篇 |
2012年 | 794篇 |
2011年 | 896篇 |
2010年 | 735篇 |
2009年 | 631篇 |
2008年 | 614篇 |
2007年 | 611篇 |
2006年 | 593篇 |
2005年 | 528篇 |
2004年 | 404篇 |
2003年 | 358篇 |
2002年 | 321篇 |
2001年 | 271篇 |
2000年 | 226篇 |
1999年 | 203篇 |
1998年 | 170篇 |
1997年 | 168篇 |
1996年 | 157篇 |
1995年 | 126篇 |
1994年 | 141篇 |
1993年 | 119篇 |
1992年 | 122篇 |
1991年 | 105篇 |
1990年 | 98篇 |
1989年 | 89篇 |
1988年 | 78篇 |
1987年 | 60篇 |
1986年 | 59篇 |
1985年 | 93篇 |
1984年 | 60篇 |
1983年 | 44篇 |
1982年 | 51篇 |
1981年 | 43篇 |
1980年 | 57篇 |
1979年 | 34篇 |
1978年 | 26篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1975年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Complete cross-sections from the femoral midshaft of 180 individuals of known height and weight, aged 21–97 y, from a modern Australian population were examined using automatic video image analysis to quantify total subperiosteal porosity (TSPP). More specifically, the aim was to investigate whether age changes were similar in both sexes in (1) total subperiosteal area (TSPA), cortical area (CA) and medullary area (MA), (2) intracortical porosity (ICP), and (3) the respective contributions to TSPP made by MA and intracortical void area (ICVA). Our findings indicated that both sexes showed a significantly greater height normalised TSPA in the 70s as compared with the 20s. Males had consistently larger bones with a greater height normalised CA. In both sexes CA showed a tendency to increase till the 7th decade and then to decline, more so in females. MA approximately trebled in females and doubled in males over the age range studied. Although ICP also increased, from 4–6% in young adults to over 9% in the elderly, it showed a significant difference between the sexes only in the 3rd decade, being greater in males at this stage. By contrast, TSPP became significantly greater in females (from that recorded in the 3rd decade) by the time they reached the 50s, while in males this did not occur till the 80s. It increased from ∼25% in young adults of both sexes to ∼50% in females and ∼37% in males in their 80s. However, in the elderly there was great variability in both sexes in the appearance of bones from individuals of similar chronological age. Some bones differed little from those in younger subjects, others showed greatly increased ICP, still others displayed reduced cortical widths with low ICP. The femoral midshaft resembles other skeletal sites in that age changes in TSPP are more marked in females than males. 相似文献
103.
目的 评价带锁髓内钉并植骨治疗股骨干陈旧性骨折的临床疗效和优点。方法 对1996年2月~2003年11月收治的47例陈旧性股骨干骨折患者进行回顾性分析。其中植骨组28例,非植骨组19例。采用切开复位,带锁髓内钉扩髓,静力型固定,根据骨折部位生长情况改为动力型固定。结果 术后随访39例,随访lO~25个月,平均随访时间14.2个月。植骨组骨折愈合率为95.6%(22/23),感染率为4.3%(1/23),骨折平均愈合时间为6.3个月,非植骨组则分别为62.5%(10/16),6.25%(1/16)和9.7个月。临近关节功能达正常,无感染、断钉等并发症。结论 带锁髓内钉静力固定能有效控制有害的剪应力,同时对骨折有一定的加压作用,可提供早期坚强的内固定,同时,植骨后骨折愈合快,并发症少,是治疗陈旧性骨折的理想方法。 相似文献
104.
J. R. M. Copeland C. McWilliam M. E. Dewey D. Forshaw R. Shiwach R. T. Abed M. S. Muthu N. Wood 《International journal of geriatric psychiatry》1986,1(1):63-70
A random community sample of 1070 subjects aged over 65 was interviewed by trained non-medical interviewers using the Geriatric Mental State, community version (GMSA). A sub-sample of 126 subjects was selected so as to contain possible early cases of dementia, pseudo-dementia, and normal subjects; and re-interviewed, a mean 1 year and 23 weeks later, by a group of psychiatrists in training. The computer diagnosis AGECAT, based on GMSA applied by non-medical raters, had predicted at initial interview, nine out of twelve cases of dementia at follow-up and five out of nine borderline cases. An Organic/Depression Index may prove useful in predicting which of those cases with early organic levels will eventually develop dementia, depression or recover. 相似文献
105.
北京和重庆市育龄期妇女风疹抗体水平调查 总被引:3,自引:0,他引:3
目的了解北京和重庆市育龄期妇女风疹抗体水平,为控制先天性风疹综合征(CRS)提供科学依据。方法2006年6~8月随机抽取北京和重庆市各1个区作为调查点,对20~39岁育龄期妇女623人(北京市311人,重庆市312人)进行血清流行病学调查。结果北京和重庆市育龄期妇女风疹抗体阳性率分别为85.21%和78.53%,自然感染获得抗体阳性率分别为85.08%和77.89%;风疹抗体分布与年龄、地区有关,随着年龄的增长抗体阳性率和几何平均浓度有下降的趋势。结论制定科学的风疹疫苗使用策略和免疫程序,提高育龄期妇女的免疫力,是减少CRS发病的有效手段。 相似文献
106.
E. Mahe 《Aesthetic plastic surgery》1998,22(1):1-8
The transconjunctival blepharoplasty is an elegant and secure technique especially in young people and helps to avoid the
hazard of a scar. In older patients, it saves them the possible sequelae such as rounding sclero show or possible ectropion
after a classical operation. Because there is no visible scar, the transconjunctival approach respects the integrity of the
functional structure of the orbital septum and the orbicular muscle, the active support of the lower eyelid. 相似文献
107.
儿童陈旧性肱骨髁上骨折手术治疗 总被引:1,自引:0,他引:1
作者对24例儿童陈旧性肱骨髁上骨折畸形愈合、影响肘关节功能恢复的病人经手术治疗,发现影响关节功能活动的主要原因是鹰咀窝及冠状窝部位的骨痂增生及骨折近端前下方移位,妨对肘关节屈伸功能。认为:清除该二部位增生分痂以及使骨折得以满意复位是治疗成功的关键。 相似文献
108.
年龄因素对健康人心率变异性的影响 总被引:1,自引:0,他引:1
目的探讨年龄因素对健康人心率变异性(HRV)的影响。材料与方法将236例健康人分为五个年龄组,使用美国先进医用设备公司5.0版本HRV软件做短时时域及频域HRV分析。结果年龄因素对健康人HRV短时时域和频域分析的多项指标产生显著影响,随着年龄增大,时域指标中的HRSD、SDANN、rMSSD及PNN50均逐渐降低;随着年龄增长,频域指标中各频段下的绝对面积,即:VLF、LF、MF及HF均逐渐降低;而频域指标中各频段下的相对面积,即:VLFP、LFP、MFP、HFP随着年龄增长呈不同的发展趋势。LF/HF随着年龄的增加而逐渐升高。结论HRV随着年龄的增加而下降,尤以迷走神经活性下降为显著。频域指标中各频段的相对面积较绝对面积能更敏感地反映交感、迷走神经张力的消长。 相似文献
109.
男性胆囊结石患者血清性激素和前列腺素改变的探讨 总被引:1,自引:0,他引:1
借助RIA,对28例胆囊结石男性(平均57.5岁)及26名健康中、老年男性(平均63.3岁)进行了血清雌二醇(E_2)、孕酮、睾酮和前列腺素类(PGs)检测,以探索胆石形成机理。结果,1)在胆石男病人中.平均E_2和平均孕酮水平均高,他们的平均睾酮则低下,与健康对照男性相应诸值比较,差异非常显著或显著(P<0.001,0.05,0.05);2)至于平均PGs,胆石男性组者与健康对照男性相比,前者也相当高(23.01pg/ml对16.31pg/ml),只是两组间差异尚无统计学意义。作者等初步设想,胆石男性小,如同胆石女性那般,本症也可能是某种垂体性腺激素分泌紊乱性疾病。 相似文献
110.
J. H. Lin A. N. Chremos K. C. Yeh J. Antonello G. A. Hessey II 《European journal of clinical pharmacology》1988,34(1):41-46
Summary The plasma and urine concentrations of famotidine, a new, potent H2-receptor antagonist, have been measured in 16 healthy young adults, 8 healthy elderly people and 18 patients with varying degrees of renal dysfunction after intravenous administration.Both the plasma elimination and renal excretion of famotidine were decreased in the elderly volunteers and renal patients. The renal clearance of famotidine averaged 4.43 ml/min/kg (310 ml/min) in normal young volunteers, which exceeded the mean creatinine clearance 1.55 ml/min/kg (109 ml/min), suggesting net secretion is a significant mechanism for elimination of famotidine.The ratio of famotidine renal clearance to creatinine clearance decreased as creatinine clearance decreased; these results suggest that the deterioration in the secretion process was much faster than that in glomerular filtration and are incompatible with the intact nephron hypothesis. Nevertheless, both total body clearance and renal clearance were significantly correlated with creatinine clearance.The apparent half-life was also significantly correlated with creatinine clearance. Since famotidine is essentially free of dose-related adverse effects, dose adjustment in patients with mild renal insufficiency and in elderly people is not required; however, either a prolonged dosing interval or a decrease in daily dose during long-term therapy may be adapted for the patients with severe renal insufficiency to avoid accumulation and the potential undesirable effects. 相似文献