全文获取类型
收费全文 | 32866篇 |
免费 | 3027篇 |
国内免费 | 1429篇 |
专业分类
耳鼻咽喉 | 343篇 |
儿科学 | 541篇 |
妇产科学 | 572篇 |
基础医学 | 3402篇 |
口腔科学 | 663篇 |
临床医学 | 4113篇 |
内科学 | 5010篇 |
皮肤病学 | 489篇 |
神经病学 | 1698篇 |
特种医学 | 1020篇 |
外国民族医学 | 9篇 |
外科学 | 2844篇 |
综合类 | 4829篇 |
现状与发展 | 11篇 |
一般理论 | 2篇 |
预防医学 | 2842篇 |
眼科学 | 858篇 |
药学 | 3806篇 |
18篇 | |
中国医学 | 1854篇 |
肿瘤学 | 2398篇 |
出版年
2024年 | 91篇 |
2023年 | 476篇 |
2022年 | 1195篇 |
2021年 | 1556篇 |
2020年 | 1148篇 |
2019年 | 1015篇 |
2018年 | 1057篇 |
2017年 | 1016篇 |
2016年 | 961篇 |
2015年 | 1360篇 |
2014年 | 1699篇 |
2013年 | 1839篇 |
2012年 | 2579篇 |
2011年 | 2668篇 |
2010年 | 1858篇 |
2009年 | 1605篇 |
2008年 | 2033篇 |
2007年 | 1935篇 |
2006年 | 1835篇 |
2005年 | 1674篇 |
2004年 | 1239篇 |
2003年 | 1124篇 |
2002年 | 1020篇 |
2001年 | 753篇 |
2000年 | 649篇 |
1999年 | 524篇 |
1998年 | 277篇 |
1997年 | 290篇 |
1996年 | 211篇 |
1995年 | 189篇 |
1994年 | 149篇 |
1993年 | 107篇 |
1992年 | 180篇 |
1991年 | 167篇 |
1990年 | 144篇 |
1989年 | 113篇 |
1988年 | 98篇 |
1987年 | 87篇 |
1986年 | 79篇 |
1985年 | 54篇 |
1984年 | 41篇 |
1983年 | 20篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1979年 | 14篇 |
1978年 | 15篇 |
1974年 | 11篇 |
1973年 | 13篇 |
1972年 | 17篇 |
1970年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
功能性矫治器是正畸临床中常用的一种矫治器,作者从口腔正畸学理论基础出发,探讨了功能性矫治器在正畸矫治作用中存在的伦理道德问题,主要有(1)不能正确的诊断、制定周密的矫治计划。(2)操作不规范、不细致、缺乏敬业精神。(3)态度简单,粗曝,缺乏与患者良好的交流。并提出解决方法(1)刻苦学习专业知识,不断提高诊疗水平及个人修养。(2)建立高度的道德责任感,以严谨的作风,规范的操作为病人服务。(3)尊重、善待青少年,建立良好的医患关系。 相似文献
62.
目的建立大鼠脑多梗死性痴呆(MID)模型及观察指标,评价药物对该模型的作用。方法采用从颈外动脉逆行注入微血栓颗粒的方法,制备MID模型,通过对术后大鼠的苏醒时间测定、倾斜板实验、神经症状评分3个方面评价动物的一般状态;采用大鼠穿梭箱实验、水迷宫实验检测各组大鼠学习记忆能力;并测定脑中丙二醛(MDA)的含量及超氧化物歧化酶(SOD)的活性,考察MID大鼠的行为学异常以及其作用机制。结果MID大鼠与正常组、假手术组比较,苏醒时间明显延长,在倾斜板上停留的时间显著变短,神经症状评分有显著差异;穿梭箱实验中电击时间明显延长,水迷宫实验学习记忆潜伏期延长;同时脑组织中MDA含量明显升高,SOD活力显著降低。给予药物氢化麦角碱(商品名:喜得镇)治疗后症状有所改善。结论该造模方法能显著造成大鼠脑多梗死性痴呆的多项体征,符合临床病理过程,为进一步判定一些药物是否具有治疗MID的前景打下基础。 相似文献
63.
Joung-Liang Lan Show-Jan Chou Der-Yuan Chen Yi-Hsing Chen Tsu-Yi Hsieh Mariano Young 《台湾医志》2004,103(8):618-623
BACKGROUND AND PURPOSE: Etanercept (Enbrel), a recombinant tumor necrosis factor receptor fusion protein, has been shown to be effective in the treatment of patients with rheumatoid arthritis (RA). The purpose of this study was to compare the efficacy and safety of etanercept in combination with methotrexate (MTX) and MTX alone in Taiwanese patients with active RA. METHODS: In this double-blind study, 58 patients with active RA who were maintained on MTX therapy at a stable dose of 12.5 to 20 mg per week for 4 weeks were randomized to receive either etanercept 25 mg (n = 29) or placebo (n = 29) by subcutaneous injection twice weekly over a period of 12 weeks. The primary endpoint was the reduction of tender and swollen joint counts by 20% (ACR 20), 50% (ACR 50), and 70% (ACR 70) as determined by the American College of Rheumatology criteria at the 12th week. RESULTS: The addition of etanercept to MTX resulted in a greater reduction in the number of tender (7.00 vs 2.45, p = 0.012) and swollen joints (8.55 vs 3.86, p = 0.017), and in serum levels of C-reactive protein (1.26 mg/dL vs 0.45 mg/dL, p = 0.014) compared to MTX alone after 12 weeks of therapy. In addition, the global assessment of disease activity by both physicians and patients, duration of morning stiffness, pain visual analog scale score, and Health Assessment Questionnaire were all improved by etanercept plus MTX therapy. Results for the overall improvement in disease activity assessed by ACR 20 (90% vs 34%), ACR 50 (66% vs 10%) and ACR 70 (24% vs 0%) all favored the etanercept plus MTX group. However, the adverse events were comparable between the 2 treatment groups. CONCLUSION: Etanercept in combination with MTX was well tolerated and provided significantly more clinical benefit than MTX alone in Taiwanese patients with active RA. 相似文献
64.
全身麻醉插管术后院内获得性肺部感染探讨 总被引:17,自引:3,他引:14
全身麻醉气管插管术后下呼吸道感染具有较高发生率。分析526例手术时间超过4小时普外科病例,经u检验发现全身麻醉气管插管术后患者肺部感染率明显高于持续性硬膜外麻醉术后患者,影响因素主要与全麻插管用具及麻醉机消毒情况有关,也与术前存在慢性阻塞性肺部疾患和术后保留气管插管有关。降低全麻术后肺部感染应重视无菌操作,尽可能对麻醉机管道进行常规消毒。 相似文献
65.
Summary Using acetylcholinesterase histochemical and choline acetyltransferase immunocytochemical localization methods, this study has provided conclusive evidence for the existence of cholinergic neurons in the external cuneate nucleus of gerbils. By light microscopy, both acetylcholinesterase and choline acetyltransferase labelling was confined to the rostral portion of the external cuneate nucleus. Ultrastructurally, acetylcholinesterase reaction products were found in the nuclear envelope, cisternae of rough endoplasmic reticulum and Golgi saccules of some somata and large dendrites as well as in the membranes of small dendrites, myelinated axons and axon terminals. These neuronal elements were also stained for choline acetyltransferase; immunoreactivity was associated with nuclear pores, nuclear envelope, perikaryal membrane and all the membranous structures within the cytoplasm. Of the total choline acetyltransferase-labelled neuronal profiles analysed, 79% were myelinated axons, 15% dendrites, 4% somata and 2% axon terminals. The immunostained axon terminals consisted of two types containing either round (Rd type; 62.5%) or pleomorphic (Pd type; 37.5%) vesicles. Both were associated directly with choline acetyltransferase-positive dendrites. In contrast to the paucity of choline acetyltransferase-labelled axon terminals, numerous choline acetyltransferase-positive myelinated axons were present. It may thus be hypothesized that most, if not all, of the external cuneate nucleus cholinergic neurons are projection cells; such cells may give rise to axonal collaterals which synapse onto their own dendrites for possible feedback control. Choline acetyltransferase-positive dendrites were contacted by numerous unlabelled presynaptic boutons, 60% of which contained round or spherical synaptic vesicles (Rd boutons) and 40% flattened vesicles (Fd boutons), suggesting that these neurons are under strong inhibitory control. The preferential concentration of cholinergic components in the rostral external cuneate nucleus may be significant in the light of the highly organized somatotopy in the external cuneate nucleus and its extensive efferent projections to medullary autonomic-related nuclei. Our results suggest that the cholinergic neurons may be involved in somatoautonomic integration. 相似文献
66.
Feng-Chun Tsai Daniel Marelli Jessica Bresson David Gjertson Reza Kermani Abbas Ardehali Fardad Esmailian Michele Hamilton Gregg C Fonarow Jaime Moriguchi Mark Plunkett Antoine Hage Julie Tran Jon A Kobashigawa Hillel Laks 《American journal of transplantation》2002,2(6):539-545
Older age, prior transplantation, pulmonary hypertension, and mechanical support are commonly seen in current potential cardiac transplant recipients. Transplants in 436 consecutive adult patients from 1994 to 1999 were reviewed. There were 251 using standard donors in 243 patients (age range 18-69 years). To emphasize recipient risk, 185 patients who received a nonstandard donor were excluded from analysis. The indications for transplant were ischemic heart disease (n = 123, 47%), dilated cardiomyopathy (n = 82, 32%), and others (n=56, 21%). One hundred and forty-nine (57%) recipients were listed as status I; 5 and 6% were supported with an intra-aortic balloon and an assist device, respectively. The 30-d survival and survival to discharge were 94.7 and 92.7%, respectively; 1-year survival was 89.1%. Causes of early death were graft failure (n = 6), infection (n = 4), stroke (n = 4), multiorgan failure (n = 3) and rejection (n = 2). Predictors were balloon pump use alone (OR= 11.4, p =0.002), pulmonary vascular resistance > 4 Wood units (OR = 5.7, p = 0.007), pretransplant creatinine > 2.0 mg/dL (OR = 6.9, p = 0.004) and female donor (OR = 8.3, p = 0.002). Recipient age and previous surgery did not affect short-term survival. Heart transplantation in the current era consistently offers excellent early and 1-year survival for well-selected recipients receiving standard donors. Early mortality tends to reflect graft failure while hospital mortality may be more indicative of recipient selection. 相似文献
67.
Hideto Kitano Jennifer M Young Jian Cheng Lan Wang Patricia D Hurn Stephanie J Murphy 《Journal of cerebral blood flow and metabolism》2007,27(7):1377-1386
Inhalation anesthetics are effective chemical preconditioning agents in experimental cerebral ischemia. However, previous work has been performed exclusively in male animals. We determined if there is a gender difference in ischemic outcome after isoflurane preconditioning (IsoPC), and if this sex-specific response is linked to differences in Akt phosphorylation or expression of neuronal inducible cell-death putative kinase (NIPK), a negative modulator of Akt activation. Young and middle-aged male and female mice were preconditioned for 4 h with air (sham PC) or 1.0% IsoPC and recovered for 24 h. Cortices were subdissected from preconditioned young male and female mice for measurement of Akt phosphorylation (Western blot) and NIPK mRNA (quantitative polymerase chain reaction). Additional cohorts underwent 2 h of reversible middle cerebral artery occlusion. Lastly, male and female Akt1(+/+) and Akt1(-/-) mice were studied to determine if gender differences in ischemic outcome after IsoPC is Akt1-dependent. Infarction volume was determined at 22 h reperfusion (2,3,5-triphenyltetrazolium chloride). As expected, IsoPC decreased ischemic damage as compared with sham PC in young and middle-aged male mice. In contrast, IsoPC markedly increased infarction in young female mice and had no effect in middle-aged female mice. Cortical phospho-Akt was increased by IsoPC versus sham PC only in male mice. No increase was observed in IsoPC female mice. NIPK mRNA was higher in female mice than in male mice regardless of preconditioning status. Male IsoPC neuroprotection was lost in Akt1-deficient male mice. We conclude that IsoPC is beneficial only in ischemic male brain and that sex differences in IsoPC are mediated through Akt activation and basal NIPK expression. 相似文献
68.
Luc G.T. Morris MD Theresa N. Tran MD Mark D. DeLacure MD 《Otolaryngology--head and neck surgery》2007,137(6):947-949
BACKGROUND: Minimally invasive esophagectomy (MIE) via thoracoscopy and laparoscopy have reduced the morbidity and mortality of total esophagectomy at experienced centers. MIE has not been evaluated in combination with major head and neck surgery, or in the otolaryngology literature. METHODS: Case series of 11 consecutive patients undergoing either open or MIE with an ablative neck procedure. RESULTS: Comparing 4 MIEs and 7 open operations, similar operative time, blood loss, and ICU and hospital length of stay were observed. There was one mortality in the open group. A 100% rate of major complications was observed in the MIE group. CONCLUSION: Our multidisciplinary team was unable to achieve improved outcomes in a series of head and neck surgical patients undergoing MIE. This result may represent an early stage of the learning curve for MIE, but may also be attributed to the escalated surgical requirements of head and neck patients. 相似文献
69.
爱母分娩工程初探——产程系列服务模式 总被引:1,自引:0,他引:1
爱母分娩工程的核心是产时分娩的管理,除医疗技术水平为重要因素外,改善产科系列服务模式,加强孕妇夫妇有关培训与健康教育,加强保健与临床的结合,对爱母分娩工程的作用亦是举足轻重的。广东省妇幼保健院试运行产时分娩管理新模式、产科系列服务新模式,提高了产科质量和社会效益及经济效益。 相似文献
70.
左旋多巴对弱视眼视诱发电位影响的研究 总被引:6,自引:0,他引:6
目的:探讨左旋多巴治疗弱视的效果。方法:正常眼和弱视眼服用单次剂量左旋多巴前后进行图形视诱发电位(pattem visual evoked poten-tial,PVEP)检测。结果:正常眼服药后中空间频率PVEP的N_1P_1振幅和高空间频率PVEP的P_1N_2振幅增大,弱视眼服药后低空间频率PVEP的N_1波潜伏期和中空间频率PVEP的P_1波潜伏期缩短。结论:左旋多巴可改善弱视眼的视功能,可作为弱视的一种新的治疗方法。眼科学报1997;13:182—185。 相似文献