全文获取类型
收费全文 | 9323篇 |
免费 | 939篇 |
国内免费 | 676篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 74篇 |
妇产科学 | 90篇 |
基础医学 | 907篇 |
口腔科学 | 145篇 |
临床医学 | 1315篇 |
内科学 | 1357篇 |
皮肤病学 | 36篇 |
神经病学 | 443篇 |
特种医学 | 295篇 |
外国民族医学 | 6篇 |
外科学 | 901篇 |
综合类 | 1868篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 836篇 |
眼科学 | 161篇 |
药学 | 995篇 |
10篇 | |
中国医学 | 621篇 |
肿瘤学 | 785篇 |
出版年
2024年 | 50篇 |
2023年 | 166篇 |
2022年 | 391篇 |
2021年 | 492篇 |
2020年 | 383篇 |
2019年 | 303篇 |
2018年 | 320篇 |
2017年 | 281篇 |
2016年 | 256篇 |
2015年 | 382篇 |
2014年 | 535篇 |
2013年 | 488篇 |
2012年 | 675篇 |
2011年 | 722篇 |
2010年 | 516篇 |
2009年 | 376篇 |
2008年 | 460篇 |
2007年 | 498篇 |
2006年 | 480篇 |
2005年 | 477篇 |
2004年 | 360篇 |
2003年 | 380篇 |
2002年 | 307篇 |
2001年 | 264篇 |
2000年 | 235篇 |
1999年 | 239篇 |
1998年 | 143篇 |
1997年 | 139篇 |
1996年 | 105篇 |
1995年 | 113篇 |
1994年 | 86篇 |
1993年 | 43篇 |
1992年 | 53篇 |
1991年 | 38篇 |
1990年 | 47篇 |
1989年 | 31篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 27篇 |
1985年 | 14篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1973年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
目的 观察新生儿暂时性呼吸困难的肺部超声特点。方法 选取2018年7月至2019年6月扬州大学医学院附属淮安市妇幼保健院收治的60例暂时性呼吸困难患儿作为观察组,选取同期60例胎龄相近的健康新生儿作为对照组。观察组患儿分别在出生后6 h内和72 h后进行肺部超声检查,对照组患儿仅在出生后6 h内进行肺部超声检查,分析其肺部超声特点。结果 超声检查发现,所有患儿均无实变发生。出生后6 h内,观察组患儿胸膜线异常、A-线消失、存在B-线、肺泡间质综合征、双肺点和胸腔积液的发生率高于对照组,差异有统计学意义(P<0.05)。观察组出生后72 h后患儿胸膜线异常、A-线消失、存在B-线、肺泡间质综合征、双肺点和胸腔积液的发生率低于出生后6 h内超声检查结果,差异有统计学意义(P<0.05)。结论 暂时性呼吸困难患儿具有胸膜线异常、A-线消失、存在B-线、肺泡间质综合征、双肺点、无实变发生和胸腔积液等特点,肺部超声对新生儿暂时性呼吸困难的早期诊断和病情监测具有重要价值。 相似文献
42.
目的 探讨胆道发育不良患儿的临床表现、病理特点、诊断、治疗及预后,提高对该病的认识.方法 回顾性分析天津市儿童医院外科2010年6月至2016年11月收治的5例胆道发育不良患儿的发病情况、治疗过程,并通过复习国内外文献对胆道发育不良的疾病特点进行总结.结果 5例胆道发育不良患儿均因生后不久出现皮肤、巩膜黄染,内科治疗病情无改善入外科治疗;肝功能检查见胆红素水平升高,以直接胆红素升高为主,伴肝酶不同程度增高;超声检查示胆囊干瘪未充盈或胆囊腔狭小,胆总管显示不清.5例患儿行手术探查,术中造影显示肝内、外胆道通畅,管腔纤细;病理检查见部分汇管区中小叶间胆管缺失,小叶间胆管/汇管区<0.5,诊断为胆道发育不良,予留置胆囊引流管,术后抗炎、补液、保肝及对症治疗.经2个月~6年门诊随访,5例患儿均存活至今,其中3例黄疸清除,1例皮肤仍黄染并伴有瘙痒,1例未退黄.结论 术前检查提示梗阻性黄疸患儿,术中造影提示胆道纤细,结合病理检查证实小叶间胆管/汇管区比例<0.5,可以明确胆道发育不良的诊断. 相似文献
43.
人胃癌SGC7901细胞膜钾离子通道的特性 总被引:8,自引:0,他引:8
目的 研究人胃癌细胞系 SGC790 1细胞膜钾离子通道特性 .方法 以人胃癌细胞系 SGC790 1为研究对象 ,采用穿孔膜片钳全细胞记录法 .结果 人的胃癌 SGC790 1细胞系的静息膜电位为 (- 32 .2± 2 .2 ) m V,在钳制电压 - 40 m V,阶跃电压在 - 80~ +80 m V,记录到一种跨膜电流 ,该跨膜电流具有电压依赖、外向整流特性 ,该电流在延迟 2 5 ms后最大激活 ,80 0 m s内不失活 ,翻转电位在 - 6 0~ - 40 m V,能被已知的钾通道的阻断剂 4- AP或 TEA阻断 .结论 在人胃癌SGC790 1细胞系细胞膜上存在延迟整流钾离子通道 . 相似文献
44.
造血干细胞移植后并发口腔粘膜炎患者的观察与护理 总被引:1,自引:0,他引:1
目的:通过对25例造血干细胞移植(HSCT)病人口腔粘膜的观察和护理,找出粘膜炎(OM)发生、发展的规律,总结有效的护理方法.方法:对移植前后的病人进行相应的口腔护理,同时观察口腔粘膜的变化情况,并将上述观察结果和护理情况进行记录.结果:25例病人中口腔粘膜炎发生率为72%,发生部位最多见于颊部和舌部,发生时间、持续时间和OM的严重程度有关,发生越早,持续时间越长,OM程度越重.结论:通过及时的观察以及细心的口腔护理,能有效降低OM的发生率,缩短愈合时间,减少病人痛苦,提高干细胞移植成功率. 相似文献
45.
46.
Shang P Shu Z Wang Y Li N Du S Sun F Xia Y Zhan S 《Asia Pacific journal of clinical nutrition》2011,20(3):404-410
The purpose of the present study was to assess the risk of the metabolic syndrome (MS) with vegan, pescovegetarian, lactovegetarian and nonvegetarian diets in Taiwan. The design was a retrospective cohort study using secondary data analysis from a Taiwan longitudinal health check-up database provided by MJ Health Screening Center during 1996-2006. A total of 93209 participants were classified as vegans (n=1116), pescovegetarians (n=2461), lactovegetarians (n=4313) and nonvegetarians (n=85319) by food frequency list of self-administered questionnaire at baseline. The association between MS or MS components and different dietary groups was evaluated using Cox proportional-hazards regression models with adjustment for confounders. During the mean 3.75 years of follow up, a total 8006 MS incident cases occurred and the incidence of MS was 229 (95% CI, 224, 234) per 10000 person year. Compared with vegans, hazard ratios of MS for nonvegetarians, pescovegetarians, lactovegetarians were 0.75 (95% CI, 0.64, 0.88), 0.68 (95% CI, 0.55, 0.83) and 0.81 (95% CI, 0.67, 0.97) after adjusting for sex, age, education status, smoking status, drinking status, physical activity at work and leisure, respectively. As for MS components, nonvegetarians and pescovegetarians had 0.72 (95% CI, 0.62, 0.84), 0.70 (95% CI, 0.57, 0.84) times risk of developing low high density lipoprotein cholesterol (HDL-C), while nonvegetarians had 1.16 (95% CI, 1.02, 1.32) times risk of developing high fasting plasma glucose. Our data suggest that the vegan diets did not decrease the risk of metabolic syndrome compared with pescovegetarian, lactovegetarian and nonvegetarian diets in a Taiwanese cohort. 相似文献
47.
In this study, the effect of the γ-valerolactone (GVL)/H2O pretreatment system on bamboo (Neosinocalamus affinis) for enzymatic hydrolysis and ethanol fermentation was investigated. The performance characterization of the pretreated bamboo substrates, including the chemical composition, the structural characteristics, and the ability to produce bioethanol, were evaluated. The recovered substrates were enzymatically hydrolyzed for 48 h and then fermented to bioethanol. For the cellulose in the raw bamboo material, the highest cellulose-to-glucose conversion yield (CGCY) was achieved at 140 °C for 2 h with GVL : H2O = 8 : 2, which was 73.39%, and the cellulose-to-ethanol conversion yield (CECY) was 67.00%. This indicated that 183.5 kg of bioethanol could be produced per ton of bamboo, which was 9.71-folds higher than that directly converted from the untreated raw bamboo powder. Under these conditions, 50.60% of the active lignin can be recovered and be used as a wood-derived feedstock for further high-valued utilization. Meanwhile, the maximum concentration of fermentation inhibitors formed after pretreatment was about 140.9 mmol L−1, and had weak inhibition to the subsequent reaction. It has been shown that the cellulose could be effectively separated from bamboo and converted into bioethanol through the GVL/H2O pretreatment system.In this study, the potential production of bamboo by the GVL/H2O system for ethanol production was investigated. 相似文献
48.
49.
Background:The SET-CAN/NUP214 fusion gene resulting from chromosomal del(9)(q34.11q34.13) or t(9;9) (q34;q34) has been found in T-cell acute lymphoblastic leukemia (T-ALL), B-cell acute lymphoblastic leukemia (B-ALL), acute myeloid leukemia (AML) and myeloid sarcoma (MS). Furthermore, the SET-CAN/NUP214 fusion gene has been found in the T-ALL cell line LOUCY and the AML line MEGAL. The common features of these cases are insensitivity to chemotherapy and poor prognosis. We reviewed the characteristics and prognostic significance of the SET-CAN/NUP214 fusion gene in hematological malignancies.Methods:This systematic literature search was conducted using the PubMed, Web of Science, Embase, and Cochrane Library databases. With the inclusion and exclusion criteria, we summarized all of the papers and performed a statistical analyses.Results:In general, the SET-CAN/NUP214 fusion gene is very rare in adult acute leukemia, more frequently found in T-ALL than in other types of leukemia, and more often in males. Flow cytometry data indicated that the markers CD34, CD33, CD13, and CD7 were common in SET-CAN/NUP214 positive acute leukemia, including ALL. Fluorescence in situ hybridization and arrays are important methods for detecting the fusion gene in newly diagnosed patients and can detect chromosomal del(9)(q34) will be detected. The chromosomal karyotype may be normal or complex, and, in terms of survival analysis, transplantation results in a better prognosis than chemotherapy alone.Conclusions and implications of key findings:The presence of SET-CAN/NUP214 fusion gene may be a Minimal Residual Disease of early recurrence, and it might be a poor indicator of outcome.Limitations:The mechanism, clinical characteristics, therapy and prognosis of the SET-CAN/NUP214 fusion gene in hematological malignancies require further research. 相似文献
50.
Commercial polyolefin separators exhibit problems including shrinkage under high temperatures and poor electrolyte wettability and uptake, resulting in low ionic conductivity and safety problems. In this work, core–shell silica-polyphosphazene nanoparticles (SiO2@PZS) with different PZS layer thicknesses were synthesized and coated onto both sides of polyethylene (PE) microporous membranes to prepare composite membranes. Compared to pure silica-coated membranes and PE membranes, the PE-SiO2@PZS composite membrane had higher ionic conductivity. With the increase in the SiO2@PZS shell thickness, the electrolyte uptake, ionic conductivity and discharge capacity gradually increased. The discharge capacity of the PE-SiO2@PZS composite membrane at 8 C rate was 129 mAh/g, which was higher than the values of 107 mAh/g for the PE-SiO2 composite membrane and 104 mAh/g for the PE membrane. 相似文献