全文获取类型
收费全文 | 43661篇 |
免费 | 4310篇 |
国内免费 | 2044篇 |
专业分类
耳鼻咽喉 | 820篇 |
儿科学 | 1045篇 |
妇产科学 | 196篇 |
基础医学 | 5559篇 |
口腔科学 | 8045篇 |
临床医学 | 3770篇 |
内科学 | 4094篇 |
皮肤病学 | 209篇 |
神经病学 | 929篇 |
特种医学 | 2121篇 |
外国民族医学 | 20篇 |
外科学 | 9531篇 |
综合类 | 6437篇 |
现状与发展 | 6篇 |
预防医学 | 1387篇 |
眼科学 | 161篇 |
药学 | 2033篇 |
23篇 | |
中国医学 | 1322篇 |
肿瘤学 | 2307篇 |
出版年
2024年 | 96篇 |
2023年 | 693篇 |
2022年 | 1382篇 |
2021年 | 1837篇 |
2020年 | 1722篇 |
2019年 | 1548篇 |
2018年 | 1420篇 |
2017年 | 1534篇 |
2016年 | 1484篇 |
2015年 | 1703篇 |
2014年 | 2765篇 |
2013年 | 3844篇 |
2012年 | 2262篇 |
2011年 | 2666篇 |
2010年 | 2354篇 |
2009年 | 2181篇 |
2008年 | 2067篇 |
2007年 | 2105篇 |
2006年 | 1887篇 |
2005年 | 1828篇 |
2004年 | 1634篇 |
2003年 | 1435篇 |
2002年 | 1214篇 |
2001年 | 1076篇 |
2000年 | 873篇 |
1999年 | 781篇 |
1998年 | 645篇 |
1997年 | 636篇 |
1996年 | 603篇 |
1995年 | 421篇 |
1994年 | 441篇 |
1993年 | 311篇 |
1992年 | 324篇 |
1991年 | 263篇 |
1990年 | 215篇 |
1989年 | 215篇 |
1988年 | 171篇 |
1987年 | 138篇 |
1986年 | 135篇 |
1985年 | 163篇 |
1984年 | 114篇 |
1983年 | 116篇 |
1982年 | 128篇 |
1981年 | 93篇 |
1980年 | 88篇 |
1979年 | 92篇 |
1978年 | 95篇 |
1977年 | 63篇 |
1976年 | 62篇 |
1975年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
应用可吸收钉棒治疗关节内骨折 总被引:5,自引:0,他引:5
目的探讨可吸收钉、棒治疗关节内骨折的效果。方法1998年6月~2004年8月,应用自身增强一聚乙酯(self-reinforced polyglycolic acid,SR—PGA)、自身增强一聚丙酯(self—reinforced poly—L—Lacticacid,SR—PLLA)可吸收螺钉、棒,手术治疗关节内骨折35例,其中男30例,女5例。年龄4~62岁。均为关节内或关节周围松质骨骨折。手术时间为伤后3h~29d。应用SR—PGA全螺纹钉9枚,SR—PLLA拉力螺钉26枚,SR—PLLA固定棒15枚。术后行骨牵引或石膏外固定。结果患者术后获随访3~60个月,平均28个月,伤口均Ⅰ期愈合;骨折于1~3个月内达临床愈合,无再移位、感染及局部积液。患者关节功能恢复满意。根据美国骨科协会(AASO)关节功能评价:优26例,良7例,可1例,差1例,优良率94.3%。结论可吸收内固定钉、棒治疗关节内及关节周围骨折,免除了患者二次手术取出内固定物的痛苦,是一种有效和较为理想的方法。 相似文献
42.
腕舟状骨疲劳骨折3例 总被引:3,自引:1,他引:2
疲劳骨折亦称行军骨折,多发生在下肢骨骼,发生在第2、3跖骨、胫骨、股骨颈等部位的疲劳骨折已不少见,但是发生在上肢的疲劳骨折尚不多见。自2002年以来,发现3例腕舟骨疲劳骨折,现报告如下。 相似文献
43.
BARI NUHOLU ALI AYYILDIZ VECIHI FIDAN ÖZDEN CEBECI UUR KOAR CANKON GERMIYANOLU 《International journal of urology》2006,13(2):109-110
OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation. 相似文献
44.
Maria A. Giovino Robert J. Hawley Matt W. Dickerson Roseann Glaser Deborah H. Meshulam Robert Ardtsini Margaret D. Rosa Rod L. Monroy 《Xenotransplantation》1997,4(2):112-119
Abstract: Establishment of mixed bone marrow chimerism in pig-to-primate transplantation, as a means of inducing specific immune tolerance, will require that both immune and nonimmune barriers be overcome. As a preliminary step in evaluating nonimmune barriers in this system, we have developed an in vitro model of engraftment in which long-term culture of porcine bone marrow-derived hematopoietic cells is supported on preformed primate bone marrow stromal layers. In the absence of cytokine supplementation, primate stromal cells were unable to support long-term porcine hematopoiesis in these cultures. Supplementation with porcine Steel Factor was required for long-term maintenance of hematopoietic progenitor cell content and total hematopoietic activity. Addition of porcine IL-3, in combination with porcine Steel Factor, increased long-term progenitor cell content and hematopoietic activity on primate stroma to levels comparable to that obtained in cultures on porcine stroma. The combination of porcine GM-CSF and Steel Factor increased progenitor cell content and hematopoietic activity early in the cultures, but had little effect in long-term cultures. The Steel Factor and IL-3 combination was species-specific in its action in these cultures, as the corresponding human cytokines were unable to effectively support long-term porcine hematopoiesis. Likewise, the combination of porcine cytokines had only minimal effects on long-term bone marrow culture of primate CD34+ cells I on primate stroma. 相似文献
45.
海脉冲营养素对小鼠造血功能的影响 总被引:3,自引:3,他引:0
通过与复方阿胶浆,施普端螺旋藻胶囊抗贫血功效的比较,研究了海脉冲营养素对小鼠造血功能的影响。结果表明,小鼠口服HMC500mg/(kg.d),对失血性贫血小鼠有提高,RBC的作用,对苯肼引起的溶血性贫血小鼠有升高Hb,RBC,WBC的作用,能促进由环磷酰胺所致骨髓抑制小鼠的骨髓有核细胞的增殖,增加脾脏重量,升高外周血中网织红细胞和WBC数量。 相似文献
46.
目的:研究健血升白冲剂对小鼠血液系统的影响。方法:以骨髓细胞计数,白细胞计数和血象为指标,观察健血升白冲剂对正常小鼠和化学及放射损伤小鼠的影响。结果:健血升白冲剂明显增加正常小鼠白细胞计数(P<001),显著改善环磷酰胺诱导小鼠白细胞和骨髓细胞的减少作用(分别为P<005,P<001),并能显著增加60Co放射损伤小鼠骨髓细胞(P<001)和白细胞(P<001)。结论:健血升白冲剂对化学及放射损伤小鼠血液系统有明显的保护及改善作用。是一个有开发价值的药物。 相似文献
47.
Monolayer cultures of normal human bone cells contain multiple subpopulations of alkaline phosphatase positive cells 总被引:5,自引:0,他引:5
Toshikatsu Matsuyama K. -H. William Lau Jon E. Wergedal 《Calcified tissue international》1990,47(5):276-283
Summary Cytochemical staining of normal human bone cells in monolayer cultures for alkaline phosphatase (ALP) indicated that the cultures
contained mixed-cell populations. Time course evaluations of the cytochemical staining revealed, in addition to the ALP-negative
cell population, at least two subpopulations of ALP-positive human bone cells with different levels of ALP. A cytochemical
method has been developed which separates the ALP-positive cells into high and intermediate ALP subpopulations. In this method,
human bone cells were stained for ALP using an azo-dye method and incubating at 4°C for 10 and 30 minutes, respectively. We
defined the cell population that stained positively for ALP at 10 minutes as strong ALP-positive cells, and both strong and
intermediate cells were stained at 30 minutes. The intermediate cells were determined from the difference between the values
at the two time points. The intra- and interassay variations of the assay, with the same investigator in blinded investigations,
were both less than 10% and the interobserver variation was approximately 25%. Analysis of the distribution of ALP levels
in cells with a laser densitometer confirmed the presence of at least three cell subpopulations. 1,25(OH)2D3 treatment increased the proportions of both ALP-positive cell populations, whereas TGF-beta treatment increased only the
intermediate ALP-positive cell population. On the contrary, fluoride increased the proportion of the strong ALP cells, and
IGF-1 had no effect on the proportions of either ALP-positive subpopulation. When the ALP-specific activity was compared with
the percentage of each ALP-positive subpopulations for the cells treated with effectors, the ALP-specific activity correlated
with the total ALP-positive and with the strong ALP-positive populations but not with the intermediate ALP-positive subpopulation.
In summary, this study represents the first evidence that normal human bone cells in monolayer cultures contained at least
two subpopulations of ALP-positive cells, and that bone cell effectors could have differential effects on each cell population. 相似文献
48.
Fumihiko Iwaku 《Journal of bone and mineral metabolism》1989,7(1):7-11
The three dimensional vascular microarchitecture of mercox resin on the lateral surface of parietal bone in Wistar strain
adult male rats (b. w. 260–350 g.) was studied in relation to bone formation by SEM observation of corrosion casts.
The microarchitecture was a single layer of network composed of precapillary artery, capillary and postcapillary vein, which
were serpigious, sometimes joined with the vein from the vascular foramen of bone. The meshes of this network, which were
irregular and varied in size, existed apart from the bone surface.
According to the report of Iwaku and Ozawa (1986), it was reported that the vascular microarchitecture of the bone surface
was very changable during the process of bone remodeling and this network, which was shown on the flat bone surface in this
study, was very similar to one in the resting phase and/or the period in which the bone formation further advanced.
From these facts and the morphological features of the bone surface observed here by SEM, it is suggested that this vascular
network was closely related with the resting stage and/or the period in which bone formation further advanced in bone remodeling. 相似文献
49.
目的 :研究老年人不同疾病时骨密度 (BMD)的分布情况。方法 :用DXADAS 6 0 0EX型骨密度仪对183例老年患者进行左侧远程桡骨加尺骨BMD检测。结果 :内分泌疾病组、消化道疾病组和其它疾病组的患病率分别为 72 7% ,2 0 6 %和 31 4 %。T值比较 :三组差异明显 (P <0 0 0 1)。累积骨丢失率 (ABLR)比较 :前一组明显高于后两组病人 (P <0 0 1)。BMD比较中 ,内分泌和其它疾病组明显低于消化道疾病组 (P <0 0 0 1)。相关分析显示 ,内分泌和消化道疾病组的年龄变化与BMD呈正相关 (r =0 5 19P <0 0 0 1和r =0 5 89P <0 0 0 1) ,内分泌疾病组和其它疾病组的体重变化与BMD呈正相关 (r=0 918P <0 0 0 1和r =0 338P <0 0 0 1)。结论 :老年人骨质疏松 (OP)患病率以内分泌疾病组最高 ,消化道疾病组较低 ;随年龄和体重增加 ,BMD降低加重。 相似文献
50.
目的:了解温州地区人群不同年龄组骨质疏松患病率及同年龄组男女骨质疏松患病的差异,强调早期预防治疗老年人及绝经期妇女骨质疏松的重要性,方法:应用单能量X线(SXA)骨密度仪测量246例正常人的右跟骨骨密度,结果:男性大于60岁组较小于60岁组骨密度(BMD)降低明显(P<0.05);女性50岁以上组与小于50岁组相比,BMD下降差异有极显性(P<0.01);各年龄组男女相比,男性BMD明显高于女性(P<0.05)。结论:女性骨质疏松症的发病大多以绝经后为主,雌激素在维持骨量方面具有重要的作用。SXA检测的跟骨含95%小梁骨,能较好地确定骨质疏松的风险水平,且其具有价廉、简便,快捷,较准确等特点,故不失为一种较好的临床筛查手段。 相似文献