全文获取类型
收费全文 | 296061篇 |
免费 | 17219篇 |
国内免费 | 414篇 |
专业分类
耳鼻咽喉 | 4205篇 |
儿科学 | 10283篇 |
妇产科学 | 10243篇 |
基础医学 | 44945篇 |
口腔科学 | 7496篇 |
临床医学 | 24147篇 |
内科学 | 55749篇 |
皮肤病学 | 6309篇 |
神经病学 | 20992篇 |
特种医学 | 11610篇 |
外国民族医学 | 43篇 |
外科学 | 46650篇 |
综合类 | 7765篇 |
现状与发展 | 1篇 |
一般理论 | 160篇 |
预防医学 | 19893篇 |
眼科学 | 6943篇 |
药学 | 20865篇 |
中国医学 | 787篇 |
肿瘤学 | 14608篇 |
出版年
2018年 | 3611篇 |
2017年 | 2650篇 |
2016年 | 3069篇 |
2015年 | 3486篇 |
2014年 | 4569篇 |
2013年 | 7198篇 |
2012年 | 9051篇 |
2011年 | 9437篇 |
2010年 | 6120篇 |
2009年 | 5542篇 |
2008年 | 8659篇 |
2007年 | 9507篇 |
2006年 | 9348篇 |
2005年 | 8944篇 |
2004年 | 8654篇 |
2003年 | 8157篇 |
2002年 | 7753篇 |
2001年 | 13318篇 |
2000年 | 13646篇 |
1999年 | 11415篇 |
1998年 | 3022篇 |
1997年 | 2788篇 |
1996年 | 2633篇 |
1995年 | 2544篇 |
1994年 | 2342篇 |
1992年 | 8312篇 |
1991年 | 8449篇 |
1990年 | 8259篇 |
1989年 | 8075篇 |
1988年 | 7313篇 |
1987年 | 7071篇 |
1986年 | 6719篇 |
1985年 | 6514篇 |
1984年 | 4760篇 |
1983年 | 4118篇 |
1982年 | 2469篇 |
1979年 | 4427篇 |
1978年 | 3228篇 |
1977年 | 2731篇 |
1976年 | 2503篇 |
1975年 | 2833篇 |
1974年 | 3352篇 |
1973年 | 3362篇 |
1972年 | 3118篇 |
1971年 | 2948篇 |
1970年 | 2838篇 |
1969年 | 2581篇 |
1968年 | 2538篇 |
1967年 | 2373篇 |
1966年 | 2264篇 |
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
71.
N Nelson O Finnstr?m L Larsson 《Scandinavian journal of clinical and laboratory investigation》1987,47(2):111-117
Thirty-one full-term newborn babies were investigated in order to establish reference values for ionized calcium. Only children fulfilling certain optimality criteria (with best possible maternal and infant conditions and uncomplicated pregnancy and delivery) were included. All infants were breast fed. Capillary blood for analysis of ionized calcium was collected by heel puncture on day 1 (6-36 h post partum, p.p.), day 3 (60-84 h p.p.) and day 5 (108-132 h p.p.). Ionized calcium was measured with a semi-automatic electrode system ICA 1 (Radiometer A/S, Copenhagen, Denmark). The reference ranges (mean +/- 2 SD) for days 1, 3 and 5 were 1.05-1.37, 1.10-1.42 and 1.20-1.48 mmol/l, respectively. The mean ionized calcium concentration on day 1 was significantly lower than on days 3 and 5. Reference values are also given for total calcium, magnesium and phosphate. We emphasize that it is impossible to calculate ionized calcium from total calcium or vice versa. 相似文献
72.
73.
74.
Joseph F Malouf Manfredi Ballo Heidi M Connolly David O Hodge Regina M Herges Charles J Mullany Fletcher A Miller 《Journal of the American Society of Echocardiography》2005,18(3):252-256
The purpose of this study was to provide, in a large number of patients, comprehensive Doppler echocardiographic assessment of normal St Jude Medical mitral valve prosthesis function using Doppler-derived hemodynamic variables, including the mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio and prosthesis performance index. The pressure half-time was less than 130 milliseconds in all patients, and all but one patient had either a peak early mitral diastolic velocity of 2 m/s or less or a mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio of less than 2.2. There was a significant (P < .001) negative correlation between the prosthesis performance index and prosthesis size. This negative correlation suggests that there is more efficient use of the in vitro geometric orifice area with smaller prostheses. 相似文献
75.
P M Schulz S C Schulz S C Goldberg P Ettigi R J Resnick R O Friedel 《The Journal of nervous and mental disease》1986,174(8):457-463
Relatives of 22 schizotypal probands were evaluated for lifetime psychiatric diagnoses. Forty-four (N = 44) of the 97 available relatives were interviewed directly using the Diagnostic Interview Schedule. The rates of psychiatric diagnoses were compared with those of sixty-six (N = 66) of 140 relatives of 30 depressed patients. Family history of mental illness was ascertained by the informant method on the remainder of relatives of both proband groups. The rate of depression found in the relatives of schizotypal patients was 52% in those directly interviewed and 25.7% when informants' reports on unavailable relatives are pooled with direct interview data. These rates were not significantly higher than those found for the relatives of depressed probands (34.8% by direct interview and 21% including reports from informants). The high rates of depression in the relatives of schizotypal probands may indicate that schizotypal personality is associated with affective disorder and not only with schizophrenia. However, the high rates may be due to the presence of depressive character traits in relatives, which inflate the rates of dysthymic disorder and other chronic depressive disorders in the relatives of borderline patients. 相似文献
76.
A V Pokrovski? P O Kazanchian G I Kuntsevich V L Buianovski? M A Vikhert 《Vestnik khirurgii imeni I. I. Grekova》1986,137(9):56-64
Results of an examination of 39 patients are described and critically assessed. An analysis of the resolving power of the method of ultrasonic angiography in pathological formations of major vessels of the neck is given. 相似文献
77.
78.
A. Roosaar L. Yin G. Sandborgh-Englund O. Nyrén T. Axéll 《Journal of oral pathology & medicine》2006,35(5):257-261
OBJECTIVES: The aim was to assess the natural course of oral lichen lesions (OLL) among unselected, non-consulting individuals. SUBJECTS AND METHODS: A cohort of 327 subjects with OLL, confirmed in 1973-1974 during a population-based survey in two Swedish municipalities, was followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 80 drawn from the 194 surviving subjects who still resided in the area in 1993-1995 was invited for interview and oral re-examination. RESULTS: At the end of follow-up, one case of oral cancer was detected, while 0.4 were expected. The overall mortality among subjects with OLL was not significantly different from that in the 15,817 OLL-free subjects who participated in the initial population based survey in 1973-1974. The lesion had disappeared in 14 (39%) of 36 re-examined subjects with white OLLs in 1973-1974, and four (11%) had transformed into red types. In the corresponding group of 19 with red forms initially, five (26%) had become lesion free and four (21%) had switched to white types. Although the cohort size does not permit firm conclusions regarding oral cancer risk, the natural course over up to 30 years appears to be benign in the great majority. 相似文献
79.
80.