全文获取类型
收费全文 | 139160篇 |
免费 | 13988篇 |
国内免费 | 9016篇 |
专业分类
耳鼻咽喉 | 1054篇 |
儿科学 | 2190篇 |
妇产科学 | 1479篇 |
基础医学 | 13400篇 |
口腔科学 | 2330篇 |
临床医学 | 19635篇 |
内科学 | 17091篇 |
皮肤病学 | 1352篇 |
神经病学 | 5754篇 |
特种医学 | 4618篇 |
外国民族医学 | 57篇 |
外科学 | 10775篇 |
综合类 | 29315篇 |
现状与发展 | 40篇 |
一般理论 | 5篇 |
预防医学 | 12440篇 |
眼科学 | 3755篇 |
药学 | 16341篇 |
195篇 | |
中国医学 | 10708篇 |
肿瘤学 | 9630篇 |
出版年
2024年 | 608篇 |
2023年 | 2295篇 |
2022年 | 5688篇 |
2021年 | 7259篇 |
2020年 | 5685篇 |
2019年 | 4383篇 |
2018年 | 4546篇 |
2017年 | 4585篇 |
2016年 | 4195篇 |
2015年 | 6451篇 |
2014年 | 8107篇 |
2013年 | 8075篇 |
2012年 | 11640篇 |
2011年 | 12500篇 |
2010年 | 8796篇 |
2009年 | 7449篇 |
2008年 | 8584篇 |
2007年 | 8362篇 |
2006年 | 7795篇 |
2005年 | 6908篇 |
2004年 | 4743篇 |
2003年 | 4276篇 |
2002年 | 3511篇 |
2001年 | 2740篇 |
2000年 | 2478篇 |
1999年 | 2146篇 |
1998年 | 1300篇 |
1997年 | 1231篇 |
1996年 | 981篇 |
1995年 | 875篇 |
1994年 | 782篇 |
1993年 | 470篇 |
1992年 | 498篇 |
1991年 | 416篇 |
1990年 | 384篇 |
1989年 | 320篇 |
1988年 | 292篇 |
1987年 | 224篇 |
1986年 | 178篇 |
1985年 | 137篇 |
1984年 | 64篇 |
1983年 | 47篇 |
1982年 | 27篇 |
1981年 | 34篇 |
1980年 | 20篇 |
1979年 | 19篇 |
1977年 | 8篇 |
1974年 | 6篇 |
1972年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Transitional mucosa adjacent to colorectal cancers is essentially characterized by an excess of sialomucins at the expense of the normally predominant sulphomucins in epithelial cells lining the intestinal crypts which presents the early stage of oncogenic transformation of colorectal epithelium. The presence or absence of sialomucins at the resection margins was studied histochemically using the high iron diamine-alcian blue(HID-AB) stain in 64 rectal cancer patients in Dukes' B stage who underwent curative anterior resection. The correlation was revealed between the presence of sialomucins at the resection margins and subsequent development of local tumour recurrence. Fourteen of 27 patients (51.9%) with sialomucins predominant pattern at either resection margin developed local recurrence compared with 4 of 37 patients (10.8%) with sulphomucins predominant pattern (P less than 0.001). It is suggested that determination of the transitional mucosa around anastomosis in patients treated for the rectal carcinoma by anterior resection appears to identify those with a higher risk of local recurrence. 相似文献
62.
Xiaohua He Edith V Sullivan Roger K Stankovic Clive G Harper Adolf Pfefferbaum 《Neuropsychopharmacology》2007,32(10):2207-2216
The relative roles of alcohol and thiamine deficiency in causing brain damage remain controversial in alcoholics without the Wernicke-Korsakoff syndrome. Experimental control over alcohol consumption and diet are impossible in humans but can be accomplished in animal models. This experiment was designed to differentiate the separate and combined effects on the macro- and ultrastructure of the corpus callosum of thiamine deficiency and voluntary alcohol consumption. Adult male alcohol-preferring (P) rats (9 chronically alcohol-exposed and 9 water controls) received a thiamine-deficient diet for 2 weeks. There were four groups: five rats previously exposed to alcohol were treated with pyrithiamine (a thiamine phosphorylation inhibitor); five rats never exposed to alcohol were treated with pyrithiamine; four alcohol-exposed rats were treated with thiamine; and four rats never exposed to alcohol were treated with thiamine. On day 14, thiamine was restored in all 18 rats; 2 weeks later the 10 pyrithiamine-treated rats received intraperitoneal thiamine. The rats were perfused 61 days post-pyrithiamine treatment at age 598 days. Brains were dissected and weight and volumes were calculated. Sagittal sections were stained to measure white matter structures. The corpus callosum was examined using transmission electron microscopy to determine density of myelinated fibers, fiber diameter, and myelin thickness. The corpus callosum in the alcohol/pyrithiamine group was significantly thinner, had greater fiber density, higher percentage of small fibers, and myelin thinning than in the alcohol/thiamine and water/thiamine groups. Several measures showed a graded effect, where the alcohol/pyrithiamine group had greater pathology than the water/pyrithiamine group, which had greater pathology than the two thiamine-replete groups. Across all 16 rats, thinner myelin sheaths correlated with higher percentage of small fibers. Myelin thickness and axon diameter together accounted for 71% of the variance associated with percentage of small fibers. Significant abnormalities in the alcohol/pyrithiamine group and lack of abnormality in the alcohol-exposed/thiamine-replete group indicate that thiamine deficiency caused white matter damage. The graded abnormalities across the dually to singly treated animals support a compounding effect of alcohol exposure and thiamine depletion, and indicate the potential for interaction between alcohol and thiamine deficiency in human alcohol-related brain damage. 相似文献
63.
长期以来的研究只能用结合试验来证明核基质结合区(MARs)的存在,对其真正的功能了解甚少.直到最近,人们才发现了MARs的一些生物学活性,MARs参与襻环的形成和染色体的高级包装,在真核生物的转录调控和凋亡方面起到了重要作用.对MARs的生物学功能仍在进一步的研究中,本文主要就MARs的结构、在转录调控中的作用及其它一些研究进展作一综述. 相似文献
64.
目的:探讨奎的平、氯氮平对精神分裂症的疗效及副作用。方法:80例患者随机分为两组,分别应用奎的平或氯氮平治疗6周,采用四级临床疗效评定标准、阳性症状与阴性症状量表(PANSS)、副反应量表(TESS)评定疗效及副反应。结果:奎的平组有效率87.5%,氯氮平组有效率82.5%。治疗第一周末,奎的平组PANSS量表总分较治疗前差异有显著性(P<0.05)。奎的平组副反应低于氯氮平组。结论:奎的平与氯氮平疗效相似,但奎的平起效较快,副反应较轻。 相似文献
65.
66.
67.
PURPOSE: The aim of this retrospective study was to analyze the characteristics of delayed panfacial fractures and evaluate treatment results. PATIENTS AND METHODS: Thirty-three patients with delayed panfacial fractures were treated in the Maxillofacial Trauma Center of Peking University, School and Hospital of Stomatology between 1998 and 2004. Each patient was examined by computed tomography (CT) scans before operation. For those who had no severe opening restriction, dental impressions were taken to fabricate dental casts. For those with severely comminuted fractures, 3-dimensional (3D) models of the facial skeleton were used. Re-establishing the continuity of the mandible was the first step and then used as a platform to reconstruct the maxillary fractures via maxillomandibular fixation after Le Fort I osteotomy. The third step was to restore the mid- and upper-facial width and projection by coronal approach to expose the zygomatic complex and frontal bone/sinus and/or naso-orbito-ethmoid (NOE) fractures. RESULTS: There were 3 types of mandibular fractures that affected the treatment plan: 1) type I, mandibular body/symphysis fracture(s) (17/33, 51.52%); 2) type II, mandibular angle and/or condylar fracture(s) (6/33, 18.18%); and 3) type III, both mandibular body/symphysis and angle/condylar fractures (10/33, 30.30%). Fourteen cases were associated with NOE fractures (42.42%) and 3 cases had frontal sinus fractures (9.1%). Twelve cases had enophthalmos (36.36%) and 3 lost 1 eyeball. The order of treatment was dependent on the mandibular fracture type. For type I fractures, reconstructing the mandibular arch was the first step. For type II fractures, repairing the angle, ascending rami, and condylar areas was the first step. For type III fractures, when both mandibular height and arch were disrupted, freeing the malunited angle or condyle was the first step before restoring the mandibular arch form. Reconstruction of the mandibular height and projection was then carried out. For all 3 types, the second step was to restore the mid- and upper facial width and projection by reducing the zygomatic complex and frontal bone/sinus or NOE fractures. Maxillary fixation across the Le Fort I level was the last step. Le Fort I osteotomy was used for all 33 cases. Bone grafts and soft tissue suspension also were used. Twenty-one cases (63.64%) had good results, 7 (21.21%) cases were acceptable, and 5 (15.15%) were not good. There were 7 cases (21.21%) that still had soft tissue problems that needed secondary operations. CONCLUSIONS: Reconstruction of the mandible first with Le Fort I osteotomy is a good way to treat delayed panfacial fractures. Computed tomography and 3D CT, model surgery, and occasionally 3D models are necessary aids for diagnosis and treatment. Soft tissue problems, including lacerations and asymmetries, were often the factors that caused an unfavorable outcome. 相似文献
68.
目的 探讨西藏地区农、牧民生活习俗与包囊虫病的关系。方法 自制问卷对 7个县 2 40个家庭 163 1名成员与包囊虫感染有关的生活习俗进行调查分析。结果 饭前便后洗手的人仅有 16 1%,餐具一般都用天然水洗 ,大部家庭用天然绵羊绒擦洗茶具。大多数人都喝过河溪水 ,池塘水 ,人人都吃半生不熟的肉 ,半数以上的吃生肉和生血肠 ,绝大多数人喝未经消毒的鲜牛、羊奶。 10 0 %家庭养狗 ,所有人员与狗、羊、牛、马接触密切。包囊虫病人占调查人数 0 43 %( 7/ 163 1) ,有典型症状者占 0 67%( 11/ 163 1)。结论 当地居民感染包囊虫与不良生活习俗有关 相似文献
69.
糖皮质激素依赖性皮炎的治疗进展 总被引:8,自引:0,他引:8
糖皮质激素依赖性皮炎临床报道中,中医、中西医结合的治疗方法最多,显示出了其优势所在,其中中药疗效优于西药,且在改善和治愈面部潮红、毛细血管扩张、色素变化、病情反跳等症状方面优势明显,对于面部痤疮样皮疹、痒及不适等症状,中、西药治疗疗效相近。目前糖皮质激素依赖性皮炎最好的治疗方法应该是中西医结合疗法。 相似文献
70.
肺血管扩张在肝肺综合征发病机制中作用的研究进展 总被引:3,自引:0,他引:3
肺血管扩张是肝肺综合征的主要发病机制,然而导致HPS肺血管扩张的机制相当复杂,至今仍不清楚.目前认为肺血管内巨噬细胞聚积和雌激素升高导致的血管活性因子增多和活性增强可能与此有关,近年来这方面的研究很多,本文对此作一综述. 相似文献