全文获取类型
收费全文 | 157082篇 |
免费 | 13223篇 |
国内免费 | 10087篇 |
专业分类
耳鼻咽喉 | 1328篇 |
儿科学 | 1915篇 |
妇产科学 | 2469篇 |
基础医学 | 17264篇 |
口腔科学 | 2766篇 |
临床医学 | 19651篇 |
内科学 | 23851篇 |
皮肤病学 | 1832篇 |
神经病学 | 8345篇 |
特种医学 | 5934篇 |
外国民族医学 | 80篇 |
外科学 | 16912篇 |
综合类 | 25985篇 |
现状与发展 | 31篇 |
一般理论 | 15篇 |
预防医学 | 10294篇 |
眼科学 | 4058篇 |
药学 | 16202篇 |
148篇 | |
中国医学 | 8344篇 |
肿瘤学 | 12968篇 |
出版年
2024年 | 433篇 |
2023年 | 2133篇 |
2022年 | 5497篇 |
2021年 | 6925篇 |
2020年 | 5148篇 |
2019年 | 4763篇 |
2018年 | 4860篇 |
2017年 | 4518篇 |
2016年 | 4205篇 |
2015年 | 6502篇 |
2014年 | 8195篇 |
2013年 | 8004篇 |
2012年 | 11663篇 |
2011年 | 12759篇 |
2010年 | 8379篇 |
2009年 | 6935篇 |
2008年 | 8830篇 |
2007年 | 8733篇 |
2006年 | 8539篇 |
2005年 | 8204篇 |
2004年 | 5689篇 |
2003年 | 5301篇 |
2002年 | 4449篇 |
2001年 | 3831篇 |
2000年 | 3800篇 |
1999年 | 3782篇 |
1998年 | 2404篇 |
1997年 | 2320篇 |
1996年 | 1686篇 |
1995年 | 1545篇 |
1994年 | 1353篇 |
1993年 | 877篇 |
1992年 | 1270篇 |
1991年 | 1131篇 |
1990年 | 972篇 |
1989年 | 853篇 |
1988年 | 731篇 |
1987年 | 687篇 |
1986年 | 532篇 |
1985年 | 485篇 |
1984年 | 261篇 |
1983年 | 182篇 |
1982年 | 123篇 |
1981年 | 122篇 |
1980年 | 77篇 |
1979年 | 123篇 |
1978年 | 60篇 |
1976年 | 54篇 |
1975年 | 58篇 |
1974年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
S Wu K Rodabaugh O Martinez-Maza J M Watson D S Silberstein C M Boyer W P Peters J B Weinberg J S Berek R C Bast 《American journal of obstetrics and gynecology》1992,166(3):997-1007
OBJECTIVE: We investigated whether monocyte-derived factors could stimulate the growth of ovarian cancer cells. STUDY DESIGN: Human peripheral blood monocytes or human monocyte-like cell lines THP-1 and U-937 were cultured with or without macrophage colony-stimulating factor, lipopolysaccharide, or phorbol myristate acetate. Culture supernatants or recombinant cytokines were assayed for growth stimulation of ovarian cancer cell lines by tritium-thymidine incorporation and direct cell counts followed by statistical analysis with Student t test. RESULTS: Conditioned medium from peripheral blood monocytes or from THP-1 or U-937 cells stimulated ovarian cancer cell growth. Interleukin-1 alpha, tumor necrosis factor-alpha, and interleukin-6 also stimulated ovarian cancer cell growth, whereas macrophage, granulocyte, and granulocyte-macrophage colony-stimulating factor did not. Concentrations of tumor necrosis factor, interleukin-1, and interleukin-6 in conditioned medium could not account for all the growth stimulation, and activity remained after neutralization of tumor necrosis factor, interleukin-1, and interleukin-6 with antibodies. CONCLUSIONS: Interleukin-1, interleukin-6, tumor necrosis factor, and additional monocyte factor(s) could provide paracrine growth stimulation when monocytes are attracted to ovarian cancers that produce macrophage colony-stimulating factor. 相似文献
144.
本文采用多种组化方法结合神经银染技术,对大鼠的食管颈段神经形态观察发现:延髓内双侧疑核的咀侧端及迷走神经背核闩平而附近,分别见散在的多极和梭形标记细胞;颈前、中节、颈胸节和胸交感节(T_2-T_4),结状节,脊神经节(C_2-C_8)内均见标记细胞。 食管壁内的神经束及分支,由粗、细两类神经纤维组成。其中AchE阳性的胆碱能纤维占优势,分别见于外膜丛、肌内丛、粘膜下丛,腺体血管周围和粘膜肌内,粗纤维末梢伸向上皮基部和上皮之间,肌内的神经末梢呈结状膨大。外膜和肌肉见有神经节和散在的神经细胞。而食管壁内肾上腺素能纤维稀少,仅见于神经束和分支内及血管壁周围。 相似文献
145.
Mistakes are inevitable in medicine. To learn how medical mistakes relate to subsequent changes in practice, we surveyed 254 internal medicine house officers. One hundred and fourteen house officers (45%) completed an anonymous questionnaire describing their most significant mistake and their response to it. Mistakes included errors in diagnosis (33%), prescribing (29%), evaluation (21%), and communication (5%) and procedural complications (11%). Patients had serious adverse outcomes in 90% of the cases, including death in 31% of cases. Only 54% of house officers discussed the mistake with their attending physicians, and only 24% told the patients or families. House officers who accepted responsibility for the mistake and discussed it were more likely to report constructive changes in practice. Residents were less likely to make constructive changes if they attributed the mistake to job overload. They were more likely to report defensive changes if they felt the institution was judgmental. Decreasing the work load and closer supervision may help prevent mistakes. To promote learning, faculty should encourage house officers to accept responsibility and to discuss their mistakes. 相似文献
146.
Songlin Wang DDS PhD Zhaoju Zou DDS FICD Qiquang Wu DDS Kaihua Sun DDS 《Journal of oral and maxillofacial surgery》1992,50(12):1332-1333
Most cases with recurrent parotitis in childhood (RPC) can be cured before puberty.1–3 A few of them, however, may continue to adulthood.1–4 To distinguish this condition from other types of chronic parotitis in adults, such as chronic obstructive parotitis,5 we suggest that the diagnosis of recurrent parotitis in adults (RPA) be reserved for the cases derived from RPC.6 The pathophysiology and development of RPA is still not well known. To our knowledge, there are few reports of RPA in the literature, especially concerning its histopathology. This report describes a cases of RPA studied with sialography and light and electron microscopy. 相似文献
147.
人甲胎蛋白时间分辨免疫荧光分析试剂盒的研制 总被引:6,自引:0,他引:6
目的研制人甲胎蛋白(hAFP)时间分辨免疫荧光分析(TRFIA)试剂盒.方法采用双抗体夹心法建立AFP TRFIA 试剂盒,对试剂盒的各项指标进行评价.结果试剂盒的可测范围为l~1 000 U/ml,灵敏度为0.17 U/ml,精密度良好,批内和批间的精密度分别为3.3%~5.9%,3.7%~6.5%.与CEA、CA12-5、CA19-9、CA15-3、白蛋白无交叉反应.稳定性试验表明试剂可以在4℃稳定1年,37℃稳定7 d.426份正常血清标本测试该试剂盒的正常参考值范围是0~12 U/ml.用本试剂盒与国外同类试剂盒同时检测60份血清标本,其相关系数为0.995.结论试剂盒各项指标(灵敏度、精密度、特异性、稳定性、准确度)均达到临床检测要求,可替代国外同类产品试剂盒. 相似文献
148.
缺血再灌流肾组织内皮素—1动态变化的实验研究 总被引:7,自引:1,他引:6
在大鼠肾缺血60分钟再灌注的模型上观察不同时相肾静脉血、肾皮质、外髓和内髓的内皮素1(ET1)浓度变化,肾组织ET1光镜和电镜免疫组织化学变化。结果发现:缺血再灌流肾组织ET1基因表达及分泌明显增强,主要分布在血管内皮细胞及平滑肌细胞、系膜细胞、肾小管上皮细胞。其分布特点与细胞类型和活性有关。本实验结果提示了缺血再灌注肾内ET1的变化规律。 相似文献
149.
Shuu-Jiun Wang Kwong-Kum Liao Hung-Hsiang Liou Shei-Shee Lee Ching-Piao Tsai Kon-Ping Lin Ko-Pei Kao Zin-An Wu 《Muscle & nerve》1994,17(4):411-418
Sympathetic skin response (SSR) and R–R interval variation (RRIV) were studied in 36 chronic, nondiabetic uremics to compare with their nerve conduction studies (NCS) and clinical dysautonomia. Abnormal SSR was noted in 5 (13.9%) patients, abnormal RRIV in 14 (38.9%), and abnormal NCS in 26 (72.2%). The patients were classified into three groups: group (GP) 1: “normal,” n = 21 (58.3%), normal RRIV and SSR; GP 2: “isolated parasympathetic dysfunction,” n = 10 (27.8%), abnormal RRIV and normal SSR; and GP 3: “sympathetic sudomotor dysfunction,” n = 5 (13.9%), abnormal SSR. A significant difference in age was found among the three groups (GP 3 > GP 2 > GP 1; P < 0.0001, ANOVA). After controlling the age factor, we still noted a tendency toward increasing NCS disturbances (distal latency and nerve conduction velocity of peroneal nerve; P < 0.05, multiple regression analysis) and frequencies of clinical autonomic symptoms (postural dizziness and impotence; P < 0.05, Mantel–Hanszel test) from GP 1 to GP 3. Patients with abnormal SSR (GP 3) displayed significantly higher frequencies of postural dizziness and impotence, indicating the relationship between an absence of SSR and clinical dysautonomia. © 1994 John Wiley & Sons, Inc. 相似文献
150.
不同来源HSP70的氨基酸组成分析 总被引:1,自引:0,他引:1
使用DEAE-52离子交换层析和ATP琼脂糖亲和层析方法,从人体肿瘤细胞株,大鼠肝脏和心脏、家兔和小鼠肝脏组织中纯化了主要的热应激蛋白-HSP70,用氨基酸自动分析仪分析它的氨基酸组成。 相似文献