全文获取类型
收费全文 | 10486篇 |
免费 | 634篇 |
国内免费 | 292篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 236篇 |
妇产科学 | 181篇 |
基础医学 | 851篇 |
口腔科学 | 68篇 |
临床医学 | 1041篇 |
内科学 | 1571篇 |
皮肤病学 | 102篇 |
神经病学 | 442篇 |
特种医学 | 174篇 |
外科学 | 645篇 |
综合类 | 2407篇 |
预防医学 | 1256篇 |
眼科学 | 32篇 |
药学 | 1394篇 |
5篇 | |
中国医学 | 497篇 |
肿瘤学 | 459篇 |
出版年
2023年 | 104篇 |
2022年 | 252篇 |
2021年 | 368篇 |
2020年 | 361篇 |
2019年 | 237篇 |
2018年 | 254篇 |
2017年 | 292篇 |
2016年 | 337篇 |
2015年 | 357篇 |
2014年 | 801篇 |
2013年 | 693篇 |
2012年 | 692篇 |
2011年 | 759篇 |
2010年 | 606篇 |
2009年 | 495篇 |
2008年 | 498篇 |
2007年 | 481篇 |
2006年 | 440篇 |
2005年 | 374篇 |
2004年 | 331篇 |
2003年 | 284篇 |
2002年 | 221篇 |
2001年 | 204篇 |
2000年 | 190篇 |
1999年 | 158篇 |
1998年 | 133篇 |
1997年 | 122篇 |
1996年 | 96篇 |
1995年 | 110篇 |
1994年 | 93篇 |
1993年 | 84篇 |
1992年 | 76篇 |
1991年 | 64篇 |
1990年 | 74篇 |
1989年 | 58篇 |
1988年 | 76篇 |
1987年 | 56篇 |
1986年 | 54篇 |
1985年 | 56篇 |
1984年 | 68篇 |
1983年 | 39篇 |
1982年 | 48篇 |
1981年 | 39篇 |
1980年 | 35篇 |
1979年 | 28篇 |
1978年 | 30篇 |
1977年 | 22篇 |
1976年 | 28篇 |
1974年 | 19篇 |
1973年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
急性有机磷中毒患者的血钾变化及临床意义的探讨 总被引:1,自引:0,他引:1
目的:探讨急性有机磷中毒患的血清钾变化及其临床意义。方法:对68例发病6小时内的急性有机磷中毒的患入院后测定血清钾,并根据不同的中毒程度、中毒方式、发病时间分组在比较,并设正常对照组对照。结果:中毒各组均有明显的低钾血症,与对照组比较均有显性意义(P<0.01),且重度中毒组与中、轻度组比较亦有显性意义(P>0.05),但两种不同的中毒途径与不同的中毒时间的组间血清钾的比较无显性意义(P>0.05)。结论:急性有机磷中毒可致明显的低钾血症,中毒越重,低钾血症越明显。在发病早期应注意监测血清钾的变化,及时纠正低血钾,预防或减轻中毒后严重合并症的产生。 相似文献
62.
常见阴离子对血清氯离子选择性电极法测定的影响 总被引:1,自引:0,他引:1
目的:研究离子选择性电极在测定血清氯时的影响因素。方法:用E-555电解质分析仪测定氟化钠、溴化钠、碳酸氢钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠以及叠氮钠溶液,并将溴化钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠分别加入Cl~-均值为100mmol/L的混合血清中观察其具体的干扰情况。结果:所测8种物质中氟化钠、碳酸氢钠的影响较小,而溴化钠、铁氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠的影响较大。结论:溴离子、碘离子、硫离子、氢氰根离子、叠氮钠对离子选择性电极法影响性较大,我们在工作中应加以重视。 相似文献
63.
Special Pharmacokinetic Considerations in Children 总被引:4,自引:2,他引:2
W. Edwin Dodson 《Epilepsia》1987,28(S1):S56-S69
Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection. 相似文献
64.
The pathogenesis of diabetic neuropathy is incompletely understood. The possibility that humoral neurotoxic factors contribute as a cause of diabetic neuropathy was tested by application of serum from patients with Type 1 and Type 2 diabetes to mouse neuroblastoma cells, which have the characteristics of adrenergic neurons in culture. Serum from patients with Type 1 diabetes and somatic neuropathy significantly inhibited both proliferation and differentiation of neuroblastoma cells, while serum from patients with Type 1 diabetes but no symptoms of neuropathy and patients with Type 2 diabetes and neuropathy had no effect on proliferation, and serum from Type 2 patients only marginally inhibited differentiation. The effects of Type 1 diabetic serum could be reversed by pre-absorption of the serum to neuroblastoma cells, and were independent of glucose levels. Immunoglobulins precipitated from the sera mimicked the effects of whole sera. These results suggest that Type 1 diabetes mellitus causes a change in serum composition, possibly related to autoimmunity, that is capable of contributing to adrenergic autonomic neuropathy in diabetic patients. 相似文献
65.
Katrina D. Ramsell Bai-Ge Zhao Daniel Baker Peter Cobbett 《Brain research bulletin》1996,39(2):109-114
The effects of serum on the morphological plasticity exhibited by pituicytes in explant cultures of the neurohypophysis of adult rats have been examined. Cultured pituicytes are normally nonstellate, protoplasmic, amorphous cells (< 25% are stellate with a distinct cell body and phase bright processes). After incubation (90 min) of pituicyte cultures in a HEPES buffered salt solution (HBSS) supplemented with isoproterenol or forskolin, the fraction of stellate pituicytes significantly increased. The increase in the fraction of stellate cells induced by isoproterenol was not reversed by subsequent incubation in isoproterenol-free HBSS for 90 min. In contrast, after stellation was induced in cultures by exposure to forskolin (90 min), the fraction of stellate cells was significantly reduced if these cultures were incubated in forskolin-free, serum (0.5%) supplemented HBSS for the same duration. Serum also blocked the increase in the fraction of stellate pituicytes induced by forskolin. These experiments suggest that serum components may have a significant role in controlling the plasticity of neuroglial relations in the neurohypophysis priviously demonstrated in vivo. 相似文献
66.
冠心病中血糖与血清微量元素间的关系分析 总被引:1,自引:0,他引:1
对75例冠心病患者依血糖水平分两组,进行12种血清微量元素测定,旨在探讨微量元素与冠心病及糖尿病间的相互关系。结果发现锌、铬、锰、硒、钴元素高血糖组较对照组血清水平为低,呈非常显著差异(P<0.0l);铜、镍元素增高,差异显著(P<0.05);而锶、铁、砷、铅、铝元素两组间无显著差异(P>0.1)。表明部分微量元素与冠心病及血糖间存在着密切联系。 相似文献
67.
目的:探讨血小板活化因子(PAF)、癌胚抗原(CEA)、糖类抗原724(CA-724)在结直肠癌(CRC)患者术前血清中的阳性表达率及与临床病理特征的关系、发病的独立危险因素。方法:选取2019年12月至2021年10月于包头医学院第一附属医院就诊的CRC患者75例为CRC组,另选取同时期在本院体检的健康志愿者75例为对照组。采用酶联免疫吸附(ELISA)法分别检测CRC患者术前及对照组的晨空腹外周静脉血PAF含量;回顾性分析上述入组患者术前血清CEA、CA-724含量,进行统计分析。结果:(1)CRC组PAF、CEA、CA-724单独检测和联合检测的阳性率分别为25.33%、42.67%、30.67%、74.67%,均高于对照组,且联合检测的阳性率均高于单独检测指标的阳性率,组间差异均具有统计学意义(P<0.05);(2)单因素方差分析结果显示,血清CEA表达水平的影响因素为患者的淋巴结转移(P<0.05);血清CA-724表达水平的影响因素为患者的年龄(P<0.05);(3)二元Logistic回归分析结果显示,PAF表达在临床病理特征之间的差异无统计学意义(P&... 相似文献
68.
探讨香萱解郁方含药血清对血清剥夺致小鼠海马神经元HT22细胞损伤模型的影响。方法 采用血清剥夺培养HT22细胞建立神经损伤体外模型,实验分为对照组、模型组和中药组[中药组A(含药血清15%浓度)、中药组B(含药血清20%浓度)],各组血清剥夺12 h后,通过CCK8法检测各组细胞活力,确定15%浓度含药血清干预后细胞的存活率最高,设定为后续实验中药组的药物浓度。免疫荧光染色法检测神经元特异性微管蛋白(β-Tubulin Ⅲ)在各组中的表达,蛋白质免疫印迹法及qPCR法检测脑源性神经营养因子(BDNF)蛋白及其mRNA在各组中的表达。结果 在加药后培养12 h,中药组的细胞活力明显高于对照组与模型组(P<0.001)。培养24 h,模型组细胞活力较对照组明显下降(P<0.001),中药组较模型组明显提高(P<0.001)。培养36 h,模型组细胞活力较对照组显著下降(P<0.001),中药组较模型组明显提高(P<0.001)。模型组BDNF蛋白含量及 BDNF mRNA表达量较对照组显著降低(P<0.05,P<0.001),模型组少数神经元长出突起;中药组BDNF蛋白含量及BDNF mRNA表达量较模型组显著增加(P<0.05),中药组HT22细胞轴突突起长度和分支增加,β-Tubulin Ⅲ阳性表达明显增多。结论 香萱解郁方含药血清对血清剥夺诱导小鼠海马神经元HT22细胞损伤具有神经保护作用,可能与促进BDNF蛋白表达有关 相似文献
69.
<正>多项研究表明,非酒精性脂肪性肝病患者(NAFLD)发生2型糖尿病(type 2 diabetes mellitus,T2DM)的风险是正常人的5倍[1-3]。在T2DM患者中,NAFLD的患病率可高达70%[4]。肝脏瞬时弹性成像技术(tran-sient elastography,TE)是近年来新兴的超声无创检查方法,主要基于超声信号在肝组织中传播受肝细胞中脂滴的影响而出现显著衰减的原理来评估肝脏脂肪性病变, 相似文献
70.
The series comprises 70 women with climacteric symptoms; 14 of them were oophorectomized. The first group of patients received 4 mg of oestriol succinate per day or a placebo in a double-blind experiment. In the second part of the study oophorectomized women were given 8 mg of oestriol succinate per day or 16 mg/day divided into two doses. Serum total cholesterol, HDL-cholesterol and serum triglycerides were estimated before drug treatment and after drug administration for three and six months. Administration of 4–16 mg/day of oestriol succinate was without effect on serum total cholesterol. A significant increase of 25–30% in HDL-cholesterol was observed following administration of oestriol succinate (8 mg or 16 mg divided into two doses) with a rising tendency in total triglyceride value. 相似文献