全文获取类型
收费全文 | 63136篇 |
免费 | 3886篇 |
国内免费 | 1720篇 |
专业分类
耳鼻咽喉 | 213篇 |
儿科学 | 1683篇 |
妇产科学 | 572篇 |
基础医学 | 5670篇 |
口腔科学 | 484篇 |
临床医学 | 6835篇 |
内科学 | 7552篇 |
皮肤病学 | 357篇 |
神经病学 | 9493篇 |
特种医学 | 3548篇 |
外国民族医学 | 1篇 |
外科学 | 4712篇 |
综合类 | 9587篇 |
现状与发展 | 7篇 |
预防医学 | 3187篇 |
眼科学 | 452篇 |
药学 | 9244篇 |
32篇 | |
中国医学 | 3580篇 |
肿瘤学 | 1533篇 |
出版年
2024年 | 99篇 |
2023年 | 715篇 |
2022年 | 1396篇 |
2021年 | 2166篇 |
2020年 | 1791篇 |
2019年 | 1515篇 |
2018年 | 1636篇 |
2017年 | 1725篇 |
2016年 | 2017篇 |
2015年 | 2031篇 |
2014年 | 3758篇 |
2013年 | 4381篇 |
2012年 | 3827篇 |
2011年 | 3794篇 |
2010年 | 3211篇 |
2009年 | 3000篇 |
2008年 | 3152篇 |
2007年 | 2977篇 |
2006年 | 2624篇 |
2005年 | 2367篇 |
2004年 | 2029篇 |
2003年 | 1820篇 |
2002年 | 1692篇 |
2001年 | 1488篇 |
2000年 | 1298篇 |
1999年 | 1170篇 |
1998年 | 958篇 |
1997年 | 971篇 |
1996年 | 837篇 |
1995年 | 800篇 |
1994年 | 691篇 |
1993年 | 614篇 |
1992年 | 605篇 |
1991年 | 551篇 |
1990年 | 472篇 |
1989年 | 413篇 |
1988年 | 422篇 |
1987年 | 389篇 |
1986年 | 317篇 |
1985年 | 436篇 |
1984年 | 403篇 |
1983年 | 232篇 |
1982年 | 292篇 |
1981年 | 251篇 |
1980年 | 251篇 |
1979年 | 207篇 |
1978年 | 184篇 |
1977年 | 170篇 |
1976年 | 147篇 |
1975年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
BACKGROUND: Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them.
OBJECTIVE: To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia.
DESIGN: A randomized controlled trial.
SETTING: Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University.
MATERIALS: Twenty healthy little pigs, either male or female, weighing 4.5–5.5 kg, were used. Neurotrend-typed multiparameter monitoring system (Diametrics Company, British); CMA/100 micro-injection pump (Carnegie Company, Sweden).
METHODS: The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups: the normothermia group (control group, n =10) and moderate hypothermia group (n =10). ① Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure (MEP), and the other for analysis of blood gases [including peripheral blood pH value, arterial partial pressure of carbon dioxide (PaCO2), arterial partial pressure of carbon dioxide (PaCO2), HCO3–]. ② Rectal temperature was monitored with mercurial thermometer. ③ Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④ Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure (CPP, CPP=MAP(ICP), brain tissue partial oxygen pressure (PO2), partial pressure of carbon dioxide (PCO2), HCO3– and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34 ℃ using ice bags, and the body temperature was maintained at 33–35 ℃ for 2 hours. The changes of the parameters were observed continuously, and the pigs in the normothermia group were not treated with cooling.
MAIN OUTCOME MEASURES: ① MAP, ICP, rectal temperature, CCP; Indexes of cerebral oxygenation detected with Neurotrend-typed multiparameter monitoring system; ② Results of blood gases analysis in the moderate hypothermia group.
RESULTS: All the 20 pigs were involved in the analysis of results. ① MAP, ICP, rectal temperature, CCP and indexes of cerebral oxygenation: In the moderate hypothermia group, the ICP after cooling was obviously lower than that before cooling [(3.31±1.19), (5.33±0.95) kPa, P < 0.05], CCP was higher, brain tissue PCO2 [(12.03±1.73), (10.59±2.01) kPa, P < 0.05], and brain tissue pH value was higher [(7.03±1.63), (9.40±1.30) kPa, P < 0.05], whereas the brain temperature was decreased as compared with that before cooling [(34.9±0.3), (37.2±0.2) ℃, P < 0.05]. ② Results of blood gases analysis in the moderate hypothermia group: There were no significant differences in the parameters of peripheral arterial blood gases analysis before and after cooling in the moderate hypothermia group (P > 0.05)
CONCLUSION: Moderate hypothermia will not impair the cerebral oxygenation, and it can reduce brain tissue CO2 and decrease brain tissue acidosis. 相似文献
102.
烧伤后机体应激导致代谢紊乱,表现为严重高分解代谢,机体损耗和抵抗力下降,严重影响患者预后。临床上主要采用生理营养指标、实验室诊断指标和能量消耗测定3类检测指标对机体代谢状况进行诊断评估,继而通过药物治疗结合非药物治疗手段加以调理支持,促进烧伤修复。目前,仍有多种诊断治疗方法尚未普及或有待完善。 相似文献
103.
家兔颈后肌受长期应力作用的实验研究 总被引:7,自引:0,他引:7
目的 建立颈后肌受长期应力作用动物模型并进行相关研究.方法 30只家兔随机分为模型组和对照组,每组15只.模型组家兔置于特制低头位框架中,低头角度为45度,每天1次,每次5小时;对照组除不低头外余条件相同.12周后分别进行颈椎X线、颈后部红外热像图、血清肌酸激酶和乳酸脱氢酶含量以及颈后肌超氧化物歧化酶和丙二醛含量观察.结果 模型组颈椎X线改变积分值实验后明显高于实验前和对照组,差异具有显著性;模型组与对照组颈后部红外热像图有明显差异;模型组血清肌酸激酶、乳酸脱氢酶的含量均明显高于对照组;模型组丙二醛含量明显高于对照组而超氧化物歧化酶含量明显低于对照组.结论 家兔颈后肌受长期应力作用后出现颈部的生物力学和生物化学失衡. 相似文献
104.
颅咽管瘤全切除术后钠代谢紊乱及处理 总被引:26,自引:5,他引:21
目的分析颅咽管瘤全切除术后钠代谢紊乱的病理生理、诊断及处理。方法对我科86例巨大颅咽管瘤(直径>3.5cm)全切除患者进行回顾性分析,根据血钠、尿钠、渗透压以及中心静脉压等确定钠代谢紊乱类型,并进行相应处理。结果发生低钠血症29例(33.7%,29/86)、高钠血症13例(15.1%,13/86)、高钠及低钠血症交替9例(10.5%,9/86)。高钠及低钠血症平均开始时间分别为术后(2.3±0.7)d和(4.8±1.6)d。2例死于严重下丘脑反应,其余钠代谢紊乱均纠正良好,平均住院时间26 d。结论钠代谢紊乱是颅咽管瘤全切除术后常见表现之一。高钠血症与尿崩症关系密切,而低钠血症主要有两个原因:脑性盐耗综合征和抗利尿激素不适当分泌综合征,二者要仔细区分,前者着重补液、补盐,而后者应在补盐的基础上要适当限水和利尿。 相似文献
105.
谷胱甘肽、自由基在砷剂诱导卵巢癌细胞凋亡中的作用 总被引:1,自引:0,他引:1
目的 观察谷胱甘肽、自由基在砷剂诱导卵巢癌细胞凋亡中的作用。方法 砷剂孵育卵巢癌细胞 4 8h后 ,琼脂糖凝胶电泳及流式细胞仪检测细胞凋亡 ,分光光度法检测细胞内谷胱甘肽、活性氧及丙二醛含量。结果 砷剂具有诱导卵巢癌细胞凋亡作用 ,砷剂诱导后细胞内谷胱甘肽含量减少 (P <0 .0 1)、活性氧及丙二醛含量增加(P <0 .0 5 )。结论 氧化还原系统的改变是砷剂诱导卵巢癌细胞凋亡的重要途径之一。 相似文献
106.
Conjugated linoleic acid (CLA) is a unique lipid that elicits dramatic reductions in adiposity in several animal models when included at < or = 1% of the diet. Despite a flurry of investigations, the precise mechanisms by which conjugated linoleic acid elicits its dramatic effects in adipose tissue and liver are still largely unknown. In vivo and in vitro analyses of physiological modifications imparted by conjugated linoleic acid on protein and gene expression suggest that conjugated linoleic acid exerts its de-lipidating effects by modulating energy expenditure, apoptosis, fatty acid oxidation, lipolysis, stromal vascular cell differentiation and lipogenesis. The purpose of this review shall be to examine the recent advances and insights into conjugated linoleic acid's effects on obesity and lipid metabolism, specifically focused on changes in gene expression and physiology of liver and adipose tissue. 相似文献
107.
腔隙性脑梗死的MRI与CT的诊断价值 总被引:1,自引:0,他引:1
目的:探讨腔隙性脑梗死的影像学特点及其临床意义,比较MRI和CT的诊断价值。方法:对120例经临床、MRI诊断明确为腔隙性脑梗死患者的病灶形态大小、部位、数量进行统计。结果:①120例行MRI检查患者共发现病灶890个,最多见于豆状核(占40.8%),其次为放射冠、丘脑、内囊、尾状核、桥脑,可为圆形、椭圆形、条索状病灶。②32例既做CT,又做MRI患者中,MRI检出的病灶数为CT的5.1倍,其中绝大多数CT漏检病灶直径≤5mm或位于幕下。结论:①腔隙性脑梗死常为多发,且第一次临床发病时多数患者颅内已存在无症状性腔隙性脑梗死病灶;②腔隙性脑梗死灶易为CT忽略,尤其是幕下病灶或≤5mm的病灶,这是造成既往文献报道腔隙性脑梗死好发部位差异较大的一个主要原因;③尽管腔隙性脑梗死病灶较小(≤10mm),但大部分(60.0%)急性期存在在周边水肿,需要相应的临床治疗。 相似文献
108.
活性氧簇是重要的氧的衍生物,氧化还原反应状态的平衡对维持机体的内环境起着重要的作用.皮肤是氧应激损害的主要靶器官,过多活性氧造成组织损伤,其主要通过影响核因子-κB、NO、蛋白激酶介导的磷酸化和基因异常表达发挥作用.多种炎症性皮肤疾病与活性氧簇相关,活性氧簇在皮炎、湿疹的发病中起着重要作用,抗氧化剂有望成为治疗这类疾病的新途径. 相似文献
109.
Nelleke G. Langerak Robert P. Lamberts A. Graham Fieggen Jonathan C. Peter Warwick J. Peacock Christopher L. Vaughan 《Child's nervous system》2007,23(9):1003-1006
Introduction Given the large number of cerebral palsy patients who have undergone selective dorsal rhizotomy in the past two decades, it
is clearly imperative that the clinical community be provided with objective and compelling evidence of the long-term sequelae
of the procedure.
Materials and methods In the early 1980s, Peacock in Cape Town shifted the site of the rhizotomy from the conus medullaris to the cauda equina,
and in the past 25 years, more than 200 children have been operated on. We have studied the incidence of spinal deformities
after multiple-level laminectomy and recorded a 20% incidence of isthmic spondylolysis or grade-I spondylolisthesis. We have
also conducted a long-term prospective gait analysis study on a cohort of 14 ambulatory patients who were operated on in 1985.
Results Ten years after surgery, our patients had increased ranges of motion that were within normal limits. Step length was significantly
improved, although cadence was unchanged postoperatively and was significantly less than normal age-matched control subjects.
Discussion We have recently tracked down all 14 patients from the original cohort and are currently completing a 20-year prospective
follow-up analysis of their neuromuscular function and gait. Our preliminary data suggest that selective dorsal rhizotomy
is not only an effective method for alleviating spasticity but it also leads to long-term functional benefits. 相似文献
110.
瘢痕疙瘩是烧伤外科研究的重要课题,其形成机制尚未完全明确,本文就其在遗传机制、免疫作用、细胞增殖与胶原代谢、细胞因子等方面的研究进展进行综述。 相似文献