全文获取类型
收费全文 | 826篇 |
免费 | 41篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 9篇 |
妇产科学 | 1篇 |
基础医学 | 64篇 |
口腔科学 | 303篇 |
临床医学 | 52篇 |
内科学 | 25篇 |
皮肤病学 | 8篇 |
神经病学 | 12篇 |
特种医学 | 24篇 |
外科学 | 39篇 |
综合类 | 117篇 |
预防医学 | 70篇 |
眼科学 | 20篇 |
药学 | 118篇 |
中国医学 | 6篇 |
肿瘤学 | 7篇 |
出版年
2023年 | 15篇 |
2022年 | 13篇 |
2021年 | 25篇 |
2020年 | 21篇 |
2019年 | 28篇 |
2018年 | 35篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 29篇 |
2014年 | 53篇 |
2013年 | 71篇 |
2012年 | 44篇 |
2011年 | 65篇 |
2010年 | 37篇 |
2009年 | 39篇 |
2008年 | 36篇 |
2007年 | 40篇 |
2006年 | 38篇 |
2005年 | 25篇 |
2004年 | 21篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 20篇 |
1998年 | 18篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1985年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有877条查询结果,搜索用时 15 毫秒
1.
用玻璃纤维表面处理剂MAC处理玻璃纤维后,再进行臭氧处理,使玻璃纤维的表面产生活性中心,引发苯乙烯、甲基丙烯酸甲酯、及丙烯酸等乙烯基单体在玻璃纤维表面上接枝聚合。接枝纤维的密度减小,对水的浸润性下降,红外光谱及扫描电镜观察证明玻璃纤维表面上接枝聚合物的存在。 相似文献
2.
3.
用玻璃纤维处理BALB/C3T3细胞,使细胞发生转化,从转化细胞中抽提DNA用以转染NIH3T3细胞,结果被转染的细胞亦发生转化。用~(32)P标记的Ha-ras癌基因作探针,通过斑点杂交,征明玻璃纤维诱发的BALB/3T3转化细胞中,Ha—ras的原癌基因被激活。 相似文献
4.
Nafe R Gangnus R Glienke W Burgemeister R Haar B Pries A Schlote W 《Pathology, research and practice》2003,199(6):411-414
The technique of laser microdissection together with laser pressure catapulting (LMPC) is demonstrated in paraffin sections obtained from surgical specimens of brain tumors mounted on glass slides. A sufficient and precise application of microdissection techniques in tissue on glass slides is worthwhile, since it offers the possibility of a retrospective analysis of archived paraffin sections in histopathology. We could demonstrate a precise dissection of areas in tissues of different thicknesses (4 microm and 20 microm). Areas of tissue mounted directly on glass need to be dissected in a scanning mode in order to remove the total region in form of small tissue fragments row by row. This mode provided a precise microdissection of tissue areas of different sizes and shapes. A successful molecular biological analysis of the microdissected regions could be demonstrated. As an example for such an analysis, differential-PCR for detecting an amplification of the gene for the epidermal growth factor receptor (EGFR) was performed. 相似文献
5.
观察缺氧及再给氧对体外培养星形胶质细胞存活能力及谷氨酸摄取功能的影响。方法:取生后1~2d新生昆明小鼠大脑皮层进行星形胶质细胞原代培养,培养 1周左右予以缺氧。缺氧时间分别为 12、24、48 h,并取缺氧24 h后再给氧0、12、24、48 h的细胞观察其形态、死亡细胞数目、乳酸脱氢酶活性及谷氨酸摄取能力的变化。结果:缺氧组及再给氧组星形胶质细胞死亡数较对照组无明显变化,缺氧前、后乳酸脱氢酶活性亦无明显改变,缺氧组谷氨酸摄取功能较对照组下降30%~60%,并随缺氧时间延长而明显下降(与对照组相比,P<0.01),再给氧24 h内谷氨酸摄取能力有所恢复,但未达正常水平。结论:星形胶质细胞与神经元相比,对缺氧培养液较为耐受,缺氧对星形胶质细胞存活能力无明显影响,但细胞摄取谷氨酸能力有所改变。 相似文献
6.
This retrospective review of seven patients with completely obstructing cancers of the left half of the colon, in addition to other reports in the literature, suggests that subtotal colectomy with primary ileal
proctostomy may be the treatment of choice for those lesions that are technically resectable and located high enough to permit an intraperitoneal ileal proctostomy. The morbidity and mortality is less than that seen with the staged approach and the length of hospitalization is shorter. By eliminating a second or third hospitalization and a temporary colostomy, palliation is better in those patients who ultimately die from recurrent cancer. Furthermore, those patients resected for cure may have increased rates of long-term survival. 相似文献
1 Clinical data on seven patients who underwent subtotal colectomy for obstructing carcinoma of the left colon: 1975–1982.
Patient | Age (yr) and Sex | Tumor Location | Hospital Stay | Comments |
1 | 68, F | Decending | 10 days | A and W 40 mo postop1 |
2 | 71, F | Sigmoid | 22 days | A and W 18 mo postop |
3 | 73, F | Sigmoid | … | A and W 5 yr postop |
4 | 66, F | Decending | 8 mo | Dead from complications |
5 | 72, M | Sigmoid | 11 days | Incidental cecal cancer; A and W 3 mo postop |
6 | 66, M | Sigmoid | 28 days | Alive with metastasis 16 mo postop |
7 | 78, M | Left transvers | 34 days | Many other polyps; A and W 9 mo postop |
- 1
- A and W = alive and well.
7.
The shape of the bladder and the optical characteristics of the tissue within the wall can be shown to play an important role in the amount of light actually received at the wall. The use of estimated doses even assuming spherical geometry, cannot therefore be relied upon. This paper describes some experimental work carried out on a glass model that was used to simulate the bladder. A specially constructed dual detector was used which consisted of an isotropic probe and semiconductor detector. This enabled measurements of irradiance and space irradiance (light energy fluence rate) to be made simultaneously. By changing the optical characteristics of the wall a four-fold increase in space irradiance was measured. Contamination of the water contained within the model by blood was also investigated and has shown that with concentrations as low as 0.5% the delivered light dose reaching the wall can be reduced by up to 50% at a wavelength of 510 nm. Some in vivo measurements are also presented together with some comments on the difficulties that have been encountered when transferring measurements from the model to the patient. 相似文献
8.
9.
目的:选择较理想的修复牙齿楔状缺损的材料和方法。方法:门诊选择141例,453颗患牙随机分为3组,分别用GC Fuji II型玻璃离子、Dyract AP复合体和GC Fuji II型玻璃离子水门汀加Charisma光固化复合树脂夹层技术修复深型楔状缺损,于修复后1、2年随访,行临床疗效观察。结果:甲组(GC Fuji II型玻璃离子)1年成功率86.67%,2年成功率75.05%;乙组(Dyract复合体)1年成功率91.61%,2年成功率87.30%;丙组(夹层技术)1年成功率93.57%,2年成功率89.43%。丙组成功率高于乙组,差异无显著性,丙组和乙组成功率均高于甲组,差异有显著性。结论:丙组(夹层技术)、乙组(Dyract AP复合体)用于楔状缺损修复的临床疗效较单纯用GC Fuji II型玻璃离子修复成功率高(P<0.05),是较理想的楔状缺损修复材料或方法。 相似文献
10.
Teena Singla I.K. Pandit Nikhil Srivastava Neeraj Gugnani Monika Gupta 《Saudi Dental Journal》2012,24(1):35-42
AimTo evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth.MethodOne hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope.ResultSignificant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth.ConclusionsGC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage. 相似文献