全文获取类型
收费全文 | 315158篇 |
免费 | 18876篇 |
国内免费 | 436篇 |
专业分类
耳鼻咽喉 | 4305篇 |
儿科学 | 10864篇 |
妇产科学 | 10781篇 |
基础医学 | 47721篇 |
口腔科学 | 7775篇 |
临床医学 | 26638篇 |
内科学 | 59413篇 |
皮肤病学 | 6737篇 |
神经病学 | 22852篇 |
特种医学 | 12323篇 |
外国民族医学 | 43篇 |
外科学 | 49077篇 |
综合类 | 8258篇 |
现状与发展 | 1篇 |
一般理论 | 175篇 |
预防医学 | 21510篇 |
眼科学 | 7201篇 |
药学 | 22123篇 |
中国医学 | 801篇 |
肿瘤学 | 15872篇 |
出版年
2021年 | 2505篇 |
2019年 | 2552篇 |
2018年 | 3969篇 |
2017年 | 2943篇 |
2016年 | 3336篇 |
2015年 | 3775篇 |
2014年 | 4991篇 |
2013年 | 7824篇 |
2012年 | 9950篇 |
2011年 | 10307篇 |
2010年 | 6610篇 |
2009年 | 6017篇 |
2008年 | 9497篇 |
2007年 | 10362篇 |
2006年 | 10211篇 |
2005年 | 9732篇 |
2004年 | 9463篇 |
2003年 | 8929篇 |
2002年 | 8413篇 |
2001年 | 13973篇 |
2000年 | 14336篇 |
1999年 | 12016篇 |
1998年 | 3238篇 |
1997年 | 2963篇 |
1996年 | 2823篇 |
1995年 | 2724篇 |
1994年 | 2510篇 |
1992年 | 8765篇 |
1991年 | 8886篇 |
1990年 | 8660篇 |
1989年 | 8430篇 |
1988年 | 7646篇 |
1987年 | 7455篇 |
1986年 | 7072篇 |
1985年 | 6868篇 |
1984年 | 5045篇 |
1983年 | 4362篇 |
1982年 | 2623篇 |
1979年 | 4662篇 |
1978年 | 3421篇 |
1977年 | 2860篇 |
1976年 | 2597篇 |
1975年 | 2945篇 |
1974年 | 3514篇 |
1973年 | 3519篇 |
1972年 | 3269篇 |
1971年 | 3078篇 |
1970年 | 2946篇 |
1969年 | 2688篇 |
1968年 | 2619篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
71.
Pyogenic liver abscess: an improvement in prognosis 总被引:3,自引:0,他引:3
Forty-six patients with pyogenic liver abscess have been treated at Paul Brousse Hospital between 1966 and 1986. The overall mortality was 24 per cent, all 11 deaths occurring in 24 patients seen prior to 1978 when there was often a considerable delay in the diagnosis of liver abscess (mean 90 +/- 71 days). In seven patients the diagnosis was not made until post-mortem examination. The mainstay of treatment was surgical drainage. Since 1978 high resolution imaging techniques for the liver, and in particular ultrasound, have been available. The diagnostic delay has been significantly reduced (mean 28 +/- 20 days, P less than 0.01). Patients are receiving definitive treatment at an earlier stage in the evolution of the disease process, with fewer established complications prior to treatment (P less than 0.05). Percutaneous drainage under ultrasound control is the preferred initial drainage procedure in high-risk patients. There have been no deaths in 22 patients treated for pyogenic liver abscess since 1978 (P less than 0.001). 相似文献
72.
Chromogenic ionophore-based methods for spectrophotometric assay of sodium and potassium in serum and plasma 总被引:1,自引:0,他引:1
A Kumar E Chapoteau B P Czech C R Gebauer M Z Chimenti O Raimondo 《Clinical chemistry》1988,34(9):1709-1712
We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high sensitivity and selectivity (negligible responses to sodium at 80 to 200 mmol/L in the potassium assay and to potassium at 0 to 10 mmol/L in the sodium assay). The within-run imprecisions are comparable with those for ion-selective electrodes (for K, 1.0% at 4.5 mmol/L; for Na, 1.1% at 136 mmol/L); the analytical range is 2-10 mmol/L for potassium, 80-170 mmol/L for sodium. The results for greater than 100 patients' samples correlated well with results obtained with ion-selective electrodes (r = 0.99 for K, 0.97 for Na). The ready-to-use aqueous reagents will be available under the trade name of ChromoLyte for use with Technicon's RA family of clinical analyzers. 相似文献
73.
74.
An increase in the number of cases of tuberculosis, especially in children, has been observed recently. Post-vaccination conversion rate in babies immunised with BCG was assessed. Sensitization was detected as early as 4 weeks after BCG inoculation. Although 84.2% had physical evidence of BCG inoculation only 69.8% had developed detectable sensitization to the tubercle bacilli as shown by the Mantoux test. 相似文献
75.
In 1985 an outbreak of ornithosis affected 13 of 80 (16%) workers in a duck-processing plant. New employees were three times more likely to become cases than established employees. The highest attack rate was in those on the production line. Following the outbreak, an occupational health scheme was set up to monitor the health of new recruits to the company. Serological evidence of recent infection was demonstrated in 18 of 37 (49%) new employees tested in the first 3 months of employment. Five (14%) also had clinical evidence of ornithosis. Veterinary investigation of the ducks demonstrated a high proportion with asymptomatic chlamydial infection. It is suggested that ornithosis may be more common in duck processors than is currently supposed. Strategies to reduce occupational risks are discussed. 相似文献
76.
Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT 总被引:3,自引:1,他引:2
M. Messinezy L. M. MacDonald T. O. Nunan N. B. Westwood S. Chinn & T. C. Pearson 《British journal of haematology》1997,98(1):103-107
Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation.
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
77.
78.
79.
The degree of metabolic acidosis at birth has been calculated in cord artery and vein samples from 21 term fetuses with cord artery pH less than 7.20. The aim of the study was to compare base deficit values calculated from either Siggaard-Andersen alignment nomogram (BD blood) or the Acid-Base chart (BD extra cellular fluid, BDecf). BDblood was found to be consistently higher in the cord artery as compared with BDecf, 13.2 +/- 3.5 and 9.9 +/- 2.9 mmol/l (Mean +/- SD), respectively. A significant correlation was found between cord artery PCO2 and BDblood whereas BDecf appeared unaffected by PCO2. In cases with cord entanglement BDecf a-v differences were increased to 3.4 +/- 2.3 mmol/l as compared with the small a-v difference noted in acidotic cases without cord entanglement, 1.1 +/- 1.25 mmol/l. It is speculated that with acutely emerging, intermittent asphyxia due to cord compression, a cord artery and vein difference in metabolic acidosis may exist and where the vein captures the basal level and the artery the acute changes. It is concluded that BDecf in both cord artery and vein add valuable information on the mechanisms behind metabolic acidosis. 相似文献
80.
Most authors consider the principal advantage of FG anastomoses (compared to microsurgical anastomoses) to be shorter operating time, reduced surgical trauma to oviduct stumps, and absence of tissue ischemia. These features promote reparative regeneration and decrease adhesion formation, resulting in complete recanalization of fallopian tubes. To date, the majority of work on FG is confined to the experimental development of surgical techniques. Investigations in reconstructive gynecological surgery are quite uncommon. The physical properties of FG and the positive results of available experimental studies suggest that further development of surgical techniques using FG in obstetrics and gynecology is worthwhile. 相似文献