全文获取类型
收费全文 | 88548篇 |
免费 | 8385篇 |
国内免费 | 6688篇 |
专业分类
耳鼻咽喉 | 952篇 |
儿科学 | 982篇 |
妇产科学 | 801篇 |
基础医学 | 9834篇 |
口腔科学 | 1512篇 |
临床医学 | 11386篇 |
内科学 | 12403篇 |
皮肤病学 | 821篇 |
神经病学 | 4658篇 |
特种医学 | 3336篇 |
外国民族医学 | 38篇 |
外科学 | 9132篇 |
综合类 | 16647篇 |
现状与发展 | 21篇 |
一般理论 | 2篇 |
预防医学 | 6633篇 |
眼科学 | 2266篇 |
药学 | 9556篇 |
85篇 | |
中国医学 | 5224篇 |
肿瘤学 | 7332篇 |
出版年
2024年 | 332篇 |
2023年 | 1444篇 |
2022年 | 3628篇 |
2021年 | 4622篇 |
2020年 | 3483篇 |
2019年 | 2915篇 |
2018年 | 3006篇 |
2017年 | 2821篇 |
2016年 | 2582篇 |
2015年 | 4156篇 |
2014年 | 5025篇 |
2013年 | 4546篇 |
2012年 | 6850篇 |
2011年 | 7404篇 |
2010年 | 5100篇 |
2009年 | 3789篇 |
2008年 | 4629篇 |
2007年 | 4788篇 |
2006年 | 4502篇 |
2005年 | 4522篇 |
2004年 | 3079篇 |
2003年 | 3059篇 |
2002年 | 2705篇 |
2001年 | 2150篇 |
2000年 | 2052篇 |
1999年 | 2013篇 |
1998年 | 1275篇 |
1997年 | 1197篇 |
1996年 | 918篇 |
1995年 | 851篇 |
1994年 | 795篇 |
1993年 | 448篇 |
1992年 | 541篇 |
1991年 | 492篇 |
1990年 | 415篇 |
1989年 | 350篇 |
1988年 | 265篇 |
1987年 | 257篇 |
1986年 | 200篇 |
1985年 | 133篇 |
1984年 | 70篇 |
1983年 | 64篇 |
1982年 | 48篇 |
1981年 | 34篇 |
1980年 | 17篇 |
1979年 | 25篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
OBJECTIVE: To understand the role of nasal mucous epithelial cells to hypoxia in early stage of nasal polyps(NP) formation. METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured without serum under normal oxygen and hypoxia, and stimulus of inflammatory cytokines. Erythropoietin (EPO) was regarded as hypoxia mark, and expression of vascular endothelial growth factor(VEGF) mRNA and protein derived from epithelial cells were detected respectively by in situ hybridization and ELISA. RESULTS: 1. Under hypoxia, EPO mRNA was expressed intensely in epithelial cells from NP and IT, and there was no significant difference between both of them. This result suggested that EPO might be regarded as a hypoxic mark. 2. The ability of producing VEGF mRNA increased with cytokines stimulation, especially under hypoxia. Protein level of VEGF from epithelial cells of NP and IT increased with cytokines stimulation, especially in hypoxia and was time-dependent. CONCLUSION: Epithelial cells actively produce vast VEGF under hypoxia. The VEGF induced by hypoxia of the mucosa in middle meatus is of importance in the formation of nasal polyps(NP) in early stage, which may be the major cause of NP formation in middle meatus. 相似文献
12.
目的 对胸腰段脊柱脊髓,马尾神经损伤患者的外科治疗及几种内固定方法的疗效进行探讨。方法 对166例患者的治疗进行回顾分析。该组患者中椎体爆裂性骨折37例,椎体压缩骨折超二分之一109例,椎体骨折脱位14例,多节段或跳跃骨折6例,脊髓损伤按Frankel分级,A级59例,B级46例,C级42例,D级19例,治疗采用后路减压复位122例,前路减压复位,髂骨植骨融合44例。结果 术后123例获3-18个月随访,随访患者中随4例RF钉断裂,5例Harrington上钩脱落,6例棍断裂,其余患者内固定稳固,脊髓,马尾神经恢复,除35例仍为A级外,余脊髓神经功能恢复1-3个级别。结论 各种不同内固定可保持或增强脊柱的稳定,胸腰段脊柱脊髓损伤的外科治疗应根据骨折类型,脊髓及马尾神经损伤程度选择手术入路及内固定材料。 相似文献
13.
保留肾单位手术治疗早期小肾癌21例临床分析 总被引:1,自引:0,他引:1
Yao-Jun Xiao Shao-Bin Zheng Wan-Long Tan Tong Chen Huan Qi Zhi-Qiang Shao Yao-Dong Jiang Peng Wu Hui-Jian Zhang 《第一军医大学学报》2005,25(3):357-359
OBJECTIVE: To evaluate the clinical effects of nephron-sparing surgery in patients with early-stage small renal cell carcinoma. METHODS: Nephron-sparing surgery was performed in 21 patients with renal cell carcinoma including 1 with solitary kidney, 3 with unilateral tumor and contralateral renal compromise, and 17 with unilateral tumor and normal contralateral kidney. The diameter of the tumors ranged from 1.5 to 6.0 cm, with a mean of 2.8 cm. The tumor diameter in 17 patients with normal contralateral kidney was less than 4 cm (mean 2.5 cm) and the average diameter in 4 patients with contralateral renal compromise was 4.2 cm. Sixteen cases were in stage T(1), 4 in stage T(2), and 1 in stage T(3). Of the 21 patients, 4 underwent tumor enucleation, 10 polar nephrectomy and 7 wedge resection. RESULTS: All patients were followed up for an average of 40.8 months (7 to 66 months). One patient suffered a right lung and mediastinum metastasis 3 years after the surgery later and 1 with chronic glomerulonephritis required dialysis 27 months after the operation. No surgical complication or local recurrence were found in other patients. CONCLUSION: As a safe and effective therapy for early-stage small renal cell carcinoma, nephron-sparing surgery can be considered as the gold-standard therapy for patients with lesions less than 4 cm in T(1) and T(2) stages of localized unilateral tumor with normal contralateral kidney. 相似文献
14.
目的:分析T1期(肿瘤直径<2cm)原发性乳腺癌女性患者绝经前后在肿瘤大小、病理分类、淋巴结转移率和数目。方法:常规病理检验以及应用免疫组化、HE法分别测定绝经前乳腺癌患者和绝经后乳腺癌患者者的ER、PR。结果:两组患者在肿瘤大小上无明显差异,但绝经前乳腺癌患者浸润导管癌的百分比为 84. 7%,绝经后乳腺癌患者的浸润导管癌百分比为 62. 2%,经χ2 检验,P<0. 01。两组淋巴结转移率分别为 39. 3%和 25. 5%,经χ2 检验,P<0. 01。两组ER和PR阳性伴淋巴结转移的比例经χ2 检验,P<0. 05。结论:绝经前乳腺癌患者和绝经后乳腺癌患者在病理分类、淋巴结转移率及数目、ER、PR阳性伴淋巴结转移上有显著性差异。对于T1原发性乳腺癌患者不论有无淋巴结转移,均应行癌肿切除伴Ⅰ、Ⅱ级淋巴结清扫。 相似文献
15.
16.
Rodica Pop-Busui Jiang Lu Neuza Lopes Teresa L. Z. Jones and the BARI D Investigators 《Journal of the peripheral nervous system : JPNS》2009,14(1):1-13
Abstract We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN. 相似文献
17.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
18.
Yulu Miao Mingxia Zhang Yulin Nie Wan Zhao Bin Huang Zhengming Jiang Shaoxiong Yu Zhibin Huang Hongjin Fu 《中国神经再生研究》2007,2(2):126-128
BACKGROUND: Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE: To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN: A comparative observation. SETTINGS: Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS: All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score (GCS) was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group (GCS ranged 14- 15 points), including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS: (1) The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. (2) The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES: Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS: Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. (1) Changes of T lymphocyte subsets: At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group (t =2.77 - 3.26, P 〈 0.01), and began to recover at 7 days, which were significantly different from those in the control group (t = 2.06 - 2.24, P 〈 0.05), and generally recovered to the normal levels at 14 days (P 〉 0.05). (2) Conditions of pulmonary infections: At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% (22/30), 0, x2=37.29, P 〈 0.01]. CONCLUSION: Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period (within 7 days), and they are easily to be accompanied by pulmonary infections. 相似文献
19.
淋巴瘤样肉芽肿与韦格内肉芽肿临床特点的比较 总被引:2,自引:0,他引:2
目的 总结淋巴瘤样肉芽肿病(lym phom atoid granulom atosis,LG)与韦格内肉芽肿( egener granulo Wm atosis,W G)的临床特点,从临床上加以鉴别。 方法 回顾性总结我院与北京协和医院 1989 年以来收治的 6 例 LG和20 例 W G 患者的临床资料,并进行比较。 结果 发热、咳嗽及呼吸困难在 LG 中较常见,流涕、鼻衄及关节痛以W G 为多,肺受累以 LG 为多,耳鼻喉、眼及肾病变在 W G 中明显增多,皮肤受损两者相似。W G 患者常有 c-ANCA 阳性及尿沉渣异常。 LG X 线胸片为双侧多发结节,边界不清,多无肺门、纵隔淋巴结肿大; G 则为双侧多发边界清晰W的结节, 易形成空洞, 肺门和纵隔淋巴结可肿大。LG 病理改变为血管中心性淋巴增生性病变, 浸润的细胞主要是小淋巴细胞和不同数量大的不典型淋巴细胞; 而在 W G 中可见坏死性血管炎及大量中性白细胞、浆细胞及少量嗜酸细胞浸润形成的肉芽肿, 部分有多核巨细胞。W G 经治疗后, 多数患者病情缓解; 则疗效不佳。 结论 LG 和 W G 在临 LG床表现、实验室检查、 影像及病理诸方面的差异有利于两者的鉴别诊断。 相似文献
20.
目的通过是否进行腭咽肌肉重建的两组腭裂修复术后患者鼻咽内窥镜的比较观察,了解腭咽部肌肉重建术后腭咽闭合状况的改变。方法将41例腭裂术后患者,按照在腭裂修复时是否进行腭咽肌肉重建分为重建组(22例)和非重建组(19例),以鼻咽纤维内窥镜记录静态和发音时腭咽闭合运动状况,对两组患者腭咽闭合运动类型和状况进行比较。结果重建组静态腭咽腔形态较非重建组明显缩小,各壁光滑丰满,未见软腭鼻腔面V型缺损畸形;动态时以环状闭合为主。非重建组静态腭咽腔形态较大,可见软腭鼻腔面V型缺损畸形;动态时以冠状闭合为主。经比较重建组腭咽闭合良好率(90.91%)明显优于非重建组(37.31%)。结论鼻咽内窥镜观察证实腭咽肌肉重建腭裂修复术后腭咽闭合功能恢复明显优于非重建组。腭裂修复术时重建腭咽肌肉有助于缩小腭咽腔和更易于达到良好的腭咽闭合状态。 相似文献