全文获取类型
收费全文 | 79216篇 |
免费 | 6414篇 |
国内免费 | 4121篇 |
专业分类
耳鼻咽喉 | 699篇 |
儿科学 | 1396篇 |
妇产科学 | 1477篇 |
基础医学 | 10174篇 |
口腔科学 | 1336篇 |
临床医学 | 9941篇 |
内科学 | 13857篇 |
皮肤病学 | 1226篇 |
神经病学 | 5490篇 |
特种医学 | 2665篇 |
外国民族医学 | 52篇 |
外科学 | 7569篇 |
综合类 | 8169篇 |
现状与发展 | 19篇 |
一般理论 | 11篇 |
预防医学 | 5987篇 |
眼科学 | 1973篇 |
药学 | 7636篇 |
62篇 | |
中国医学 | 3062篇 |
肿瘤学 | 6950篇 |
出版年
2024年 | 184篇 |
2023年 | 1093篇 |
2022年 | 2691篇 |
2021年 | 3634篇 |
2020年 | 2561篇 |
2019年 | 2624篇 |
2018年 | 2863篇 |
2017年 | 2272篇 |
2016年 | 2355篇 |
2015年 | 3227篇 |
2014年 | 4082篇 |
2013年 | 3791篇 |
2012年 | 5959篇 |
2011年 | 6466篇 |
2010年 | 3763篇 |
2009年 | 3029篇 |
2008年 | 4394篇 |
2007年 | 4414篇 |
2006年 | 4372篇 |
2005年 | 4340篇 |
2004年 | 3177篇 |
2003年 | 3072篇 |
2002年 | 2697篇 |
2001年 | 1339篇 |
2000年 | 1399篇 |
1999年 | 1545篇 |
1998年 | 1093篇 |
1997年 | 1024篇 |
1996年 | 813篇 |
1995年 | 724篇 |
1994年 | 587篇 |
1993年 | 422篇 |
1992年 | 480篇 |
1991年 | 408篇 |
1990年 | 369篇 |
1989年 | 325篇 |
1988年 | 320篇 |
1987年 | 262篇 |
1986年 | 267篇 |
1985年 | 216篇 |
1984年 | 158篇 |
1983年 | 127篇 |
1982年 | 84篇 |
1981年 | 85篇 |
1980年 | 74篇 |
1979年 | 114篇 |
1978年 | 56篇 |
1975年 | 51篇 |
1974年 | 63篇 |
1973年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
手术结及打结方法的规范与进展 总被引:6,自引:0,他引:6
打结是手术的最基本技术之一,主要包括结扎打结(结扎血管、胆管、淋巴管等)、固定打结(固定引流管、引流条等)及缝合打结。手术不论大小都不能不做许多重复的打结动作,学习手术技术正是从学打结、练打结开始的。由于打结的操作太习以为常,许多手术医生对打结不够重视,对各种手术结并没有一个全面的了解和认识,甚至每日都在重复着不规范的打结操作。手术打结操作是否正确、熟练程度如何等不仅体现了手术医生的基本素质,而且直接关系到手术的效果,甚至关系到病人的安危。 相似文献
72.
Ana C Mendes M Madalena Caldeira Claudia Silva Shawn C Burgess Matthew E Merritt Filipe Gomes Cristina Barosa Teresa C Delgado Fatima Franco Pedro Monteiro Luis Providencia John G Jones 《Magnetic resonance in medicine》2006,56(5):1121-1125
Menthol glucuronide was isolated from the urine of a healthy 70-kg female subject following ingestion of 400 mg of peppermint oil and 6 g of 99% [U-(13)C]glucose. Glucuronide (13)C-excess enrichment levels were 4-6% and thus provided high signal-to-noise ratios (SNRs) for confident assignment of (13)C-(13)C spin-coupled multiplet components within each (13)C resonance by (13)C NMR. The [U-(13)C]glucuronide isotopomer derived via direct pathway conversion of [U-(13)C]glucose to [U-(13)C]UDP-glucose was resolved from [1,2,3-(13)C(3)]- and [1,2-(13)C(2)]glucuronide isotopomers derived via Cori cycle or indirect pathway metabolism of [U-(13)C]glucose. In a second study, a group of four overnight-fasted patients (63 +/- 10 kg) with severe heart failure were given peppermint oil and infused with [U-(13)C]glucose for 4 hr (14 mg/kg prime, 0.12 mg/kg/min constant infusion) resulting in a steady-state plasma [U-(13)C]glucose enrichment of 4.6% +/- 0.6%. Menthol glucuronide was harvested and glucuronide (13)C-isotopomers were analyzed by (13)C NMR. [U-(13)C]glucuronide enrichment was 0.6% +/- 0.1%, and the sum of [1,2,3-(13)C(3)] and [1,2-(13)C(2)]glucuronide enrichments was 0.9% +/- 0.2%. From these data, flux of plasma glucose to hepatic UDPG was estimated to be 15% +/- 4% that of endogenous glucose production (EGP), and the Cori cycle accounted for at least 32% +/- 10% of GP. 相似文献
73.
Sergio Navarro-Gutiérrez Félix González-Martínez Maria Teresa Fernández-Pérez Maria Teresa García-Moreno Maria Rosa Ballester-Vidal Francisco J Pulido-Morillo 《European journal of emergency medicine》2003,10(4):331-333
Alterations in blood glucose levels are known to be involved in electrocardiogram changes. Various types of arrhythmias have been reported. We present here the case of an 81-year-old woman presenting with transient atrial fibrillation while being treated for hypoglycaemia with dextrose infusion, and finally developing a sinus rhythm. The presence of alterations in glucose blood levels should always be considered as a potential cause of transient atrial fibrillation. 相似文献
74.
Poly-L-Lysine玻片在寡核苷酸芯片制备中的改进 总被引:1,自引:0,他引:1
目的 为了制得适合固定未修饰寡核苷酸的芯片,提高检测灵敏性,对Patrick Brown实验室的多聚左旋赖氨酸包被玻片的方法进行改进。方法 玻片经清洗后用缩水甘油-丙氧基三甲氧基硅烷进行硅烷化,然后应用Poly-L-Lysine在玻片表面形成聚合物涂层,经次亚苯基二异硫氰酸盐表面活化后可使寡核苷酸共价连接在芯片表面。设计了各种实验考察方法改进前后芯片表面的性能,并将改进后的玻片初步应用于SARS冠状病毒寡核苷酸芯片检测中。结果 方法改进后芯片表面性能优良:固定效率高、点的同一性好、杂交效率和热稳定性好、寡核苷酸结合牢固、芯片可以重复利用。结论 利用共价连接,方法改进后的芯片表面适合固定未修饰的寡核苷酸,解决了寡核苷酸与玻片之间物理结合不稳定、易剥离的缺陷,提高了芯片检测的灵敏性。 相似文献
75.
Chun-Hsiung Huang Fang-Yuan Ho Hon-Ming Ma Chan-Tsung Yang Jiann-Jong Liau Hung-Chan Kao Tai-Horng Young Cheng-Kung Cheng 《Journal of orthopaedic research》2002,20(5):1038-1041
Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G). 相似文献
76.
目的:分析左主干起源于右冠状动脉窦的临床特征,提高对左主干起源于右冠状动脉窦的认识和诊断.方法:回顾分析2例左主干起源于右冠状动脉窦的临床病例并对文献进行回顾分析.结果:左主干起源于右冠状动脉窦是一种罕见的先天性冠脉畸形,这种畸形可分为良性或恶性,主要根据异常左冠状动脉与主动脉和肺动脉之间的关系.对于可能引起猝死或严重心肌缺血患者,应进行冠状动脉旁路移植术.2例患者左主干起源于右冠状动脉窦,其中1例左主干走行于主动脉与肺动脉之间,1例走行于主动脉前方,这2例未进行预防性外科手术,目前预后良好.结论:左主干起源于右冠状动脉窦是罕见的冠脉畸形,应注意鉴别是良性或是恶性,确定下一步治疗方案. 相似文献
77.
78.
Scott W. Powers Kelly C. Byars Monica J. Mitchell Susana R. Patton Teresa Schindler Margaret H. Zeller 《Children's Health Care》2003,32(4):297-311
This pilot study examined a behavioral treatment to increase calorie intake in toddlers with cystic fibrosis. Eight toddlers were randomly assigned to behavioral plus nutrition (BEH) or nutrition intervention (NTR) conditions. Calorie intake and weight were measured at pre- and posttreatment. The BEH group showed a trend for changes in calorie intake pre- to posttreatment (p = .07; 40% increase). Results for the BEH and NTR groups did not differ significantly. Most participants achieved weight gains consistent with normal growth. Seventy-five percent had not shown this pattern during the year prior to intervention. These results support the feasibility and potential for behavioral interventions in this age group. 相似文献
79.
Intestinal permeability is increased in several disorders such as Crohn's disease or rheumatoid arthritis. Since aging leads to alteration of many biological functions, the effect of aging on intestinal permeability was studied by measuring the intestinal permeability in aging rats gavaged with different size permeability probes--mannitol, polyethylene glycol (PEG) 400, and inulin. In rats fed with control diet, there was a significant increase in intestinal permeability to medium size probes PEG 400 (14.8 +/- 0.4 and 21.0 +/- 1.1% at 3 and 28 months respectively, p less than .01) and mannitol (3.41 +/- 0.4 and 5.3 +/- 0.5% at 3 and 28 months, respectively, p less than .01). Intestinal permeability of the large macromolecule inulin did not change (0.42 +/- 0.03 and 0.38 +/- 0.02% at 3 and 28 months, respectively) with aging. There was no correlation between weight of the rats and their intestinal permeability. Because dietary caloric restriction has been found to prolong the life span, retard deterioration of several biological functions, and affect intestinal absorptive functions, we examined the effect of lifelong calorie restriction on intestinal permeability changes. Lifelong calorie-restricted diet did not affect age-related change in intestinal permeability. We conclude that intestinal permeability of medium size probes increases with aging and that lifelong caloric restriction does not prevent this change. We speculate that age-associated deterioration in intestinal barrier functions could permit increased systemic absorption of lumenal antigens and could perhaps contribute to the genesis of antigen-related age-associated diseases. 相似文献
80.
Clinical observation of Qi deficiency syndrome in 72 patients with chronic obstructive pulmonary disease treated with Yiqi Mianyi Granule 下载免费PDF全文
Seventy-two patients of chronic obstructive pulmonary disease (COPD) of Qi deficiency syndrome with abnormal immune indices were treated with Yiqi Mianyi Granule (YQMYG) and the efficacy was compared with that of 30 cases treated with Zhenqi fuzheng Granule (ZQFZG) for control. Results showed that the markedly effective rate of symptomatic improvement of Qi deficiency in YQMYG group was 65.3%, the total effective rate 93.1%. 88.6% of the immune indices lower than normal were corrected and 43. 7% of them were normalized, while for indices that were higher than normal the rate were 78.2% and 52.9% respectively. These results suggested that YQMYG could improve symptom of Qi Deficiency markedly, strengthen cellular immunity and regulate immune dysfunction. Its therapeutic efficacy was obviously superior to ZQFZG (P<0.Q5). 相似文献