全文获取类型
收费全文 | 52312篇 |
免费 | 4278篇 |
国内免费 | 1584篇 |
专业分类
耳鼻咽喉 | 618篇 |
儿科学 | 634篇 |
妇产科学 | 1090篇 |
基础医学 | 8162篇 |
口腔科学 | 1414篇 |
临床医学 | 4355篇 |
内科学 | 10029篇 |
皮肤病学 | 1000篇 |
神经病学 | 3758篇 |
特种医学 | 1693篇 |
外国民族医学 | 6篇 |
外科学 | 7305篇 |
综合类 | 3969篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 2957篇 |
眼科学 | 1375篇 |
药学 | 4716篇 |
中国医学 | 755篇 |
肿瘤学 | 4332篇 |
出版年
2023年 | 196篇 |
2022年 | 317篇 |
2021年 | 546篇 |
2020年 | 348篇 |
2019年 | 621篇 |
2018年 | 1124篇 |
2017年 | 870篇 |
2016年 | 862篇 |
2015年 | 967篇 |
2014年 | 1284篇 |
2013年 | 1580篇 |
2012年 | 2144篇 |
2011年 | 2080篇 |
2010年 | 1253篇 |
2009年 | 1234篇 |
2008年 | 1842篇 |
2007年 | 1951篇 |
2006年 | 1817篇 |
2005年 | 1491篇 |
2004年 | 1358篇 |
2003年 | 1326篇 |
2002年 | 1258篇 |
2001年 | 4633篇 |
2000年 | 4545篇 |
1999年 | 3907篇 |
1998年 | 1373篇 |
1997年 | 998篇 |
1996年 | 607篇 |
1995年 | 499篇 |
1994年 | 449篇 |
1993年 | 412篇 |
1992年 | 1931篇 |
1991年 | 1675篇 |
1990年 | 1528篇 |
1989年 | 1491篇 |
1988年 | 1296篇 |
1987年 | 1190篇 |
1986年 | 1063篇 |
1985年 | 899篇 |
1984年 | 588篇 |
1983年 | 467篇 |
1982年 | 250篇 |
1981年 | 180篇 |
1980年 | 141篇 |
1979年 | 281篇 |
1978年 | 79篇 |
1976年 | 67篇 |
1974年 | 77篇 |
1973年 | 96篇 |
1972年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Xie S Gong GL Xiao JX Ye JT Liu HH Gan XL Jiang ZT Jiang XX 《American journal of ophthalmology》2007,143(4):642-646
PURPOSE: To detect the abnormalities of the optic radiation (OR) in children with amblyopia by diffusion tensor imaging (DTI) and tractography. DESIGN: Prospective, nonrandomized clinical trial. METHODS: Fourteen children with amblyopia and 14 normally sighted children underwent DTI scanning. After the ORs were reconstructed by using tractography algorithm, voxels through which the anterior parts of ORs passed were determined for their values of fractional anisotropy (FA). The paired t test was applied to compare their mean FA values of right OR and left OR in the control group. For the amblyopia group, analysis of variance was conducted to determine the effect of laterality and vision status on the FA values. In addition, the voxel numbers of anterior and posterior parts of both ORs were calculated. The Student t test was used to compare the average FA of bilateral ORs and voxel numbers between the two groups. RESULTS: Comparison demonstrated left-higher-than-right asymmetry in both amblyopic children and normal children. We found no significant difference of average FA between the amblyopic group (0.4832 +/- 0.0225) and control group (0.4770 +/- 0.0273). Voxel numbers of the anterior parts of both ORs were not significantly different between the two groups, whereas voxel numbers of their posterior parts in the controls were more than that of amblyopic children. CONCLUSION: Tractography showed more voxels in the posterior ORs of normal children than in the amblyopic children, indicating that normal children have better development of the ORs. The underdevelopment of the ORs might reflect the dysfunction of visual cortex in children with amblyopia. 相似文献
992.
From November 1986 to February 1989, 18 patients with traumatic carotid-cavernous fistulas were treated by means of detachable balloon, which was made by ourselves. Successful embolization was achieved in 15 patients. Draining features of the fistulas and methods of embolization were introduced. The method was compared with other methods. Selection of treatments and problems in embolization are discussed.
相似文献
993.
994.
L S Xiao F R Niu G J Xing Y W Fu L S Zhao Z Y Liu X P Znang 《Hinyokika kiyo. Acta urologica Japonica》1988,34(5):814-818
Clinical and statistical investigations were performed on 157 patients with prostate carcinoma in the Third Teaching Hospital, Normal Bethune University experienced between January, 1950 and June, 1986. The number of patients with prostate carcinoma among other hospitalized patients showed a recent gradual increase. The patient's age at the time the disease was first diagnosed was most frequently between 60 and 69 years old with an average age of 63.3 years. Dysuria was the most prominent symptom, followed by frequency, retention and macroscopic hematuria. Duration between initial symptom and diagnosis was one to two years in most patients. The prostatic abnormality could be detected by rectal examination in all patients. Elevation of serum acid phosphatase was found in 24.4%. Such elevation was evident in 52.2% of the patients with metastatic lesions, compared to 14.4% of those without metastasis. Fourteen patients had metastasis to bone (8.9%), 13 to lymph nodes, 2 to lung and one to liver. According to the staging diagnosis, 19 patients (12.1%) had stage A, 78 patients (49.7%) had stage B, 20 patients (12.7%) had stage C and 40 patients (25.5%) had stage D carcinoma. Histological findings in 57 patients indicated adenocarcinomas; 39 cases (68.4%) were poorly differentiated, 12 cases (21.2%) were moderately differentiated and 6 cases (10.5%) were well differentiated. Modality of treatment was total prostatectomy in 2 cases (1.3%), antiandrogen therapy (orchiectomy and/or Stilbestrol) in 122 cases (77.7%), subcapsular prostatectomy in 7 cases (4.5%), symptomatic treatment in 5 cases and no treatment in 23 cases (14.6%). 相似文献
995.
The epidemiology of childhood burns in Jiamusi, China 总被引:5,自引:0,他引:5
Z X Zhu H Yang F Z Meng 《Burns : journal of the International Society for Burn Injuries》1988,14(5):394-396
The causes and severities of burning injury were analysed in 1006 children admitted to our department over a 11-year period. A substantial number of patients were less than 5 years old. Proportionally more boys and less girls were injured. More of the accidents occurred in summer and winter and less during the spring and autumn; more occurred in the rural and mountain areas than in the cities. In the younger children 88 per cent of the injuries occurred at home while eating and drinking, only a few burns happening in kindergarten and school. This report suggests which methods of prevention should be stressed. 相似文献
996.
C Deville X Roques G Fernandez N Laborde E Baudet F Fontan 《European journal of cardio-thoracic surgery》1988,2(3):185-191
Our experience (January 1982-May 1987) concerns 41 patients, operated upon for aortic dissection (30 patients) or aneurysm (11 patients) using circulatory arrest with deep hypothermia. There were 24 male and 17 female patients (mean age: 55 years 9 months, range 32-73 years). The mean circulatory arrest time in minutes was 41 +/- 3 (mean rectal temperature before circulatory arrest was 18.4 degrees C +/- 0.3 degrees C). Total (24 patients) or partial (16 patients) replacement of the aortic arch was performed. One patient with a sacciform aneurysm had the aortic wall defect closed. Hospital mortality was 22% +/- 7% (9 patients): 8 of 30 patients with aortic dissection (26.6%) and 1 of 11 patients with aortic aneurysm (9%). Neurological complications occurred in 3 patients. These data lead us to prefer circulatory arrest with deep hypothermia as the method of choice for aortic arch surgery. However, when a short circulatory arrest time (less than 30 min) for the repair is foreseeable, mild hypothermia (20 degrees C-24 degrees C) may be preferred. In patients who will not tolerate excessive cardiopulmonary bypass times, expected difficulties with the repair should suggest mild hypothermia and short circulatory arrest in easier cases or moderate hypothermia with brachiocephalic perfusion in the others. 相似文献
997.
Pharmacokinetics and protein binding of bupivacaine were studied after caudal injection of 2.5 mg/kg in 13 ASA PS 1 infants (1-6 months of age) scheduled for elective hernia repair. Blood was sampled at frequent intervals from 5 min to 600 min in all but one patients. Additional samples were taken at 720 and 840 min in five patients. Bupivacaine concentration was measured using gas chromatography. Protein binding was measured using ultrafiltration. Peak serum concentrations ranged between 0.55 and 1.93 micrograms/ml. The time to reach the peak ranged from 10 to 60 min. Terminal half-life (T1/2 beta) was 7.7 +/- 2.4h (mean +/- SD), the volume of distribution (Vss) was 3.9 +/- 2.01.kg, and the total body clearance (CL) was 7.1 +/- 3.2 ml.min.kg-1. The free fraction was markedly increased (0.16 +/- 0.07) when compared with published adult values, and showed a highly significant negative correlation with age. Alpha 1 acid glycoprotein measured in the same infants correlated significantly with age. In conclusion, pharmacokinetics of caudal bupivacaine in infants are characterized by Cmax of total drug similar to those observed in adults after epidural injection. The free fraction is increased at least until 6 months of life. This suggests caution in the use of bupivacaine in infants until we understand the clinical significance of this increased free fraction. 相似文献
998.
The skeletal effects of flurbiprofen (Fb), a nonsteroidal antiinflammatory drug, was studied by histomorphometry in 9-month-old retired female breeder, Sprague-Dawley rats. Flurbiprofen was given subcutaneously at 0, 0.2, 0.1, 0.5, 2.5, or 5 mg/kg/d for 21 days. Flurbiprofen had no effect on longitudinal growth, but stimulated radial growth (+200%) over controls. In the tibial shaft, Fb stimulated the mineral apposition rate (+25%), mineral bone formation rate (+100%), and periosteal labeling length (+64%) at the 2.5 and 5.0 mg Fb/kg dose levels, and had no effect on marrow cavity size compared to controls. However, these changes were insufficient to increase cortical bone mass. In the proximal tibial metaphysis, Fb suppressed osteoclasts/mm2 of metaphyseal tissue (-47%), osteoclasts/mm of bone surface (-46%), and the osteoclast/osteoblast ratio (-50%), increased the calcified cartilage core population (+100%), and had no effect on osteoblast numbers at all dose levels. There was an insignificant increase in metaphyseal cancellous bone mass. The current study leads to the conclusion that flurbiprofen-stimulated periosteal bone growth was due to direct stimulation of osteoblast recruitment and activity independent of longitudinal bone growth. Further, it confirms early findings in young rats that flurbiprofen induced depressed bone resorption without lowering bone formation. However, because of insufficient treatment time, the older rat did not accumulate bone as the young rats did. 相似文献
999.
Following experimental investigations on animals, small coral grafts have been utilized on patients since 1985 to fill in burr holes (42 patients). This first clinical experimental step has been satisfactory. Therefore, blocks of corals have since then been used as bone graft substitutes for anterior skull basis reconstruction (12 patients). Cheap and easily sterilized, coral implants have the advantage of being inert (99% of calcium carbonate), biodegradable and well reossified. They shorten surgical procedures by avoiding the use of iliac and/or costal grafts. No infectious complications have been noted. 相似文献
1000.
The aim of this study was to assess the feasibility, validity, reliability and sensitivity to change of a Spanish version of the Dermatology Life Quality Index (DLQI) in patients with mild to moderate eczema and psoriasis who were treated with topical corticosteroids. The final study sample comprised 237 patients (48% eczema). Discriminant validity was tested by comparing patients' scores with those of a random sample of the general population (n = 100), and convergent validity by analysing correlations between DLQI scores, measures of clinical severity, and domain scores on the Nottingham Health Profile (NHP). Internal consistency and test-retest reliability were tested in clinically stable patients (n = 94), and responsiveness in a clinically unstable group (n = 143) initiating treatment with topical corticosteroids. Patient scores were significantly higher than general population scores (4.3 vs. 0. 27, P < 0.001). Correlations with NHP domains ranged from 0.12 to 0. 32, and there was significant correlation with clinical measures (r = 0.26, P < 0.001). Reliability was good (Cronbach's alpha = 0.83; intraclass correlation coefficient = 0.88), and the instrument proved responsive to change (effect size for the total group of de novo patients = 0.70), though the great majority of changes occurred in items 1 and 2. The NHP Emotional Reactions and Mobility domains were more responsive than some DLQI domains. In clinical trials of treatments for mild to moderate eczema and psoriasis, it is likely that only items 1 and 2 of the DLQI will be needed, and it is probably advisable to include generic instruments alongside the DLQI. 相似文献