全文获取类型
收费全文 | 2999篇 |
免费 | 109篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 133篇 |
妇产科学 | 81篇 |
基础医学 | 217篇 |
口腔科学 | 135篇 |
临床医学 | 216篇 |
内科学 | 617篇 |
皮肤病学 | 80篇 |
神经病学 | 176篇 |
特种医学 | 236篇 |
外科学 | 544篇 |
综合类 | 165篇 |
预防医学 | 81篇 |
眼科学 | 75篇 |
药学 | 167篇 |
1篇 | |
中国医学 | 63篇 |
肿瘤学 | 89篇 |
出版年
2023年 | 20篇 |
2022年 | 31篇 |
2021年 | 76篇 |
2020年 | 49篇 |
2019年 | 46篇 |
2018年 | 66篇 |
2017年 | 59篇 |
2016年 | 86篇 |
2015年 | 82篇 |
2014年 | 107篇 |
2013年 | 140篇 |
2012年 | 198篇 |
2011年 | 203篇 |
2010年 | 130篇 |
2009年 | 119篇 |
2008年 | 145篇 |
2007年 | 209篇 |
2006年 | 180篇 |
2005年 | 187篇 |
2004年 | 157篇 |
2003年 | 106篇 |
2002年 | 116篇 |
2001年 | 49篇 |
2000年 | 42篇 |
1999年 | 43篇 |
1998年 | 55篇 |
1997年 | 46篇 |
1996年 | 52篇 |
1995年 | 28篇 |
1994年 | 25篇 |
1993年 | 30篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 28篇 |
1988年 | 23篇 |
1987年 | 16篇 |
1986年 | 22篇 |
1985年 | 19篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 17篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 11篇 |
1974年 | 6篇 |
1972年 | 4篇 |
排序方式: 共有3148条查询结果,搜索用时 859 毫秒
31.
目的观察小分割分次立体定向放射治疗(fractionated stereotatic radiation therapy,FSRT)脑转移瘤的近期疗效.方法15例病人单纯全脑外照射(WBRT组),中间平面剂量20~40Gy/10~20次/2~4周.17例病人接受FSRT(FSRT组),每次分次剂量为2.5~3.0Gy.其中11病人行单纯FSRT,中心总剂量为30~60Gy/1 0~20次/2~4周;6例病人先行WBRT,然后行FSRT,中心总剂量为46~60Gy/5~6周.结果KSP评分增加10分以上者,WBRT组为5 3.3%,FSRT组为82.4%.(P<0.05).WBRT组有效率(CR PR)为50.0%;FSRT组有效率(CR PR)为80.0%.中位生存率:WBRT组为3.5月,FSRT组为10.0月.结论FSRT能有效地控制脑转移瘤,减轻神经系统症状,提高生存质量,延长病人生存期,而没有增加副作用,值得临床推广应用. 相似文献
32.
OBJECTIVES: The cystoscopic follow-up of superficial bladder cancer accounts for a considerable workload for urologists and is also an invasive procedure with high costs. There is a potential benefit both to the urologist and the patient if unnecessary cystoscopies can be avoided. METHODS: The recurrence and progression rates of 120 patients with pTa G1 or G2 and small (<4 cm) transitional cell carcinoma were evaluated retrospectively. RESULTS: The recurrence rate was 6.5% (8/120) at 3 months. The recurrence rates at 6 and 9 months were 6.7 (8/119) and 3.6% (4/112), respectively. However, when the third month (first check) was clear, the recurrence rates at 6- and 9-month cystoscopy were 4.3 (5/116) and 2.7% (3/111), respectively. The recurrence rate at 12 months was 8% (8/99). For G1 tumors, the recurrence rates at 3, 6, 9 and 12 months were 6 (5/84), 5 (5/83), 2.5 (2/80) and 7% (5/71), respectively. The same results for G2 tumors were 8 (3/36), 8 (3/36), 6 (2/32) and 10.5% (3/28), respectively. The progression rate for the first year was lower than 1%. The difference between G1 and G2 tumors according to recurrence rate within the first year was not statistically significant (p>0. 05). CONCLUSIONS: This study supports the proposal that for patients with small and welldifferentiated pTa tumors at diagnosis, if the first control cystoscopy is clear, it is appropriate to perform the second check cystoscopy 1 year from initial resection and subsequent controls yearly. One should note that the study group included the most suitable patients for cystoscopic follow-up according to size and multiplicity of the tumor. This change in policy is further supported by the fact that progression occured in less than 1% in this group of patients. 相似文献
33.
Our objective was to compare the relationship between age, basal follicle stimulating hormone (FSH) level and ultrasound-measured mean ovarian volume (MOV) and mean antral follicle counts (MFC) in a group of infertile and fertile women between the ages of 35 and 45 years. Menstrual cycle day 3 serum FSH, MOV and MFC were analyzed in 62 infertile and 53 fertile women. Basal FSH and MFC did not differ between infertile and fertile women, whereas MOV was significantly smaller in infertile women (p < 0.05). In the infertile group, there was a negative correlation between MOV and age (rho = -0.389, p < 0.05), between MOV and basal FSH (rho = 0.495, p < 0.01), and between MFC and age (rho = -0.553, p < 0.01). In the fertile group, there was a strong negative correlation between MOV and basal FSH (rho = -0.631, p < 0.01), and between MFC and basal FSH (rho = -0.710, p < 0.01). Mean basal FSH, MOV and MFC did not differ between subgroups of patients with different causes of infertility. In the infertile group, patients with small ovaries of volume less than 1.8 cm(3) (mean volume -1 SD) had higher mean basal FSH (p < 0.05) and lower MFC (p < 0.01) levels than patients with normal ovarian volume. In conclusion, transvaginal ultrasound (TVU) indices and indirect hormonal parameters of ovarian reserve were similar in infertile and fertile women aged between 35 and 45 years. It is suggested that, in infertile women above 35 years of age, TVU rather than hormonal parameters be preferred, based on our data showing a stronger association between age and TVU indices of ovarian reserve than between age and increase in basal FSH level. Thus, TVU assessment of ovarian volume and antral follicle counts is a practical and cost-effective, if not better, technique for ovarian reserve testing. 相似文献
34.
35.
36.
We compared the tumor-initiating activities toward mouse skin of two
structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic
anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide
(5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5-
methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol
epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is
derived from the non-planar parent compound 5,6- dimethylchrysene, and
reacts to approximately equal extents with dA and dG in DNA, whereas
5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene,
and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33,
100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse,
respectively. It was significantly less tumorigenic than 5-MeCDE which
induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors
induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in
codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had
this mutation at the 33, 100 and 400 nmol doses. No mutations were found in
codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast,
CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by
5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had
mutations at G of codons 12 and 13. The results of this comparative study
support the hypothesis that mutations in the Ha-ras gene in mouse skin
tumors induced by PAH diol epoxides occur as a result of their direct
reaction with the gene. However, pathways other than the commonly observed
Ha- ras codon 61 mutations are clearly important in mouse skin
tumorigenesis by these diol epoxides.
相似文献
37.
Percutaneous nephrolithotomy in older children 总被引:4,自引:0,他引:4
Sahin A Tekgül S Erdem E Ekici S Hasçiçek M Kendi S 《Journal of pediatric surgery》2000,35(9):1336-1338
PURPOSE: The aim of this study was to evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) in pediatric patients, older than 8 years, without any technical and instrumental modifications. METHODS: The authors retrospectively evaluated the data of 16 percutaneously treated kidneys of 14 patients with a mean age of 11 years (range, 8 to 17). The mean stone burden was calculated as 301 mm2 (range, 120-750). Percutaneous accesses were done under fluoroscopic control, and 24F to 30F Amplatz dilators were used depending on patient size. Ultrasonic and laser lithotripsy were performed to fragment calculi. RESULTS: Mean operating time was 111 minutes (range, 60 to 210 min) and no intraoperative or postoperative major complication was observed. Mean hemoglobin drop after the procedure was 1.16 g/dL (range, 0.3 to 2.8). Blood transfusion was required in only 1 patient, and mean postoperative hospitalization was 4.6 days (range, 3 to 10). Stone-free rate was calculated as 69% (11 of 16), but with residual fragments smaller than 4 mm, the success rate becomes 100% at patient's discharge. CONCLUSIONS: PCNL is an effective and safe form of therapy in pediatric stone disease. Especially in older children the use of the same instruments and technique as in adults may achieve equal results without any increased risk of possible morbidity and need of blood transfusion. 相似文献
38.
39.
40.