全文获取类型
收费全文 | 14798篇 |
免费 | 785篇 |
国内免费 | 212篇 |
专业分类
耳鼻咽喉 | 114篇 |
儿科学 | 254篇 |
妇产科学 | 204篇 |
基础医学 | 1316篇 |
口腔科学 | 152篇 |
临床医学 | 2070篇 |
内科学 | 1307篇 |
皮肤病学 | 96篇 |
神经病学 | 2803篇 |
特种医学 | 682篇 |
外科学 | 1194篇 |
综合类 | 1723篇 |
一般理论 | 2篇 |
预防医学 | 1186篇 |
眼科学 | 99篇 |
药学 | 1153篇 |
9篇 | |
中国医学 | 230篇 |
肿瘤学 | 1201篇 |
出版年
2024年 | 23篇 |
2023年 | 174篇 |
2022年 | 413篇 |
2021年 | 571篇 |
2020年 | 501篇 |
2019年 | 421篇 |
2018年 | 487篇 |
2017年 | 470篇 |
2016年 | 442篇 |
2015年 | 417篇 |
2014年 | 981篇 |
2013年 | 1096篇 |
2012年 | 727篇 |
2011年 | 924篇 |
2010年 | 683篇 |
2009年 | 774篇 |
2008年 | 783篇 |
2007年 | 698篇 |
2006年 | 672篇 |
2005年 | 499篇 |
2004年 | 453篇 |
2003年 | 398篇 |
2002年 | 274篇 |
2001年 | 295篇 |
2000年 | 231篇 |
1999年 | 242篇 |
1998年 | 193篇 |
1997年 | 201篇 |
1996年 | 196篇 |
1995年 | 163篇 |
1994年 | 148篇 |
1993年 | 115篇 |
1992年 | 115篇 |
1991年 | 101篇 |
1990年 | 96篇 |
1989年 | 71篇 |
1988年 | 88篇 |
1987年 | 65篇 |
1986年 | 54篇 |
1985年 | 84篇 |
1984年 | 75篇 |
1983年 | 52篇 |
1982年 | 67篇 |
1981年 | 42篇 |
1980年 | 41篇 |
1979年 | 38篇 |
1978年 | 24篇 |
1977年 | 31篇 |
1976年 | 24篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Donald E. Addington Emily McKenzie Jean Addington Scott Patten Harvey Smith Carol Adair 《Early intervention in psychiatry》2007,1(2):157-167
Aim: The purpose of this project was to operationalize and apply a previously identified set of performance measures designed to evaluate services for those experiencing a first episode of a schizophrenia spectrum disorder. Methods: Operational definitions were developed for previously identified measures through an iterative process of discussions between clinical experts and health‐care evaluators. Data were collected from existing sources including corporate databases, clinical databases and chart review. Results: Definitions were developed for 44 measures covering seven of eight domains recommended for service level evaluation by the Canadian Institute for Health Information domains. Forty measures could be calculated. Conclusions: The measures represent a comprehensive set of performance measures suitable for the evaluation of services for people with a first‐episode psychosis. The measures could be used by other services in order to establish standards and norms for routine clinical practice. 相似文献
12.
目的 探讨肺炎衣原体(Chlamydia pneumoniae)感染在多发性硬化(MS)发病和进展中的作用和致病机制。方法 选取急性期MS患者31例,缓解期MS患者28例及其他神经系统疾病患者30例,健康对照者30名,应用酶联免疫吸附试验测定患者和对照者血清及脑脊液中肺炎衣原体IgG和IgM抗体水平。结果 急性期MS组、缓解期MS组、其他神经系统疾病组和健康对照组的肺炎衣原体血清IgG分别为48.4%、35.7%、30.0%、23.3%;4组IgM抗体效价分别为12.9%、14.3%、20.0%、10.0%,总体比较差异无统计学意义(P〉0.05);急性期MS组与其他神经系统疾病组的脑脊液IgG和IgM抗体效价分别为0、6.7%和0、0,差异无统计学意义(P〉0.05)。结论 肺炎衣原体的感染或重复感染与MS发病相关不紧密,可能仅为MS的伴随感染。 相似文献
13.
多发性硬化患者血清尿酸水平变化的研究 总被引:2,自引:0,他引:2
目的 探讨多发性硬化 (MS)患者血清尿酸 (UA)水平的变化及其临床意义。方法 采用酶定量分析法对 4 3例MS患者和 4 5名正常对照者的血清UA水平进行检测。结果 MS组血清UA水平明显低于对照组 (P <0 0 1)。MS组中病程越长 (P <0 0 1)、神经伤残程度越重 (DSS评分越高 ) (P <0 0 5 ) ,血清UA水平越低 ;女性患者UA水平明显低于男性患者 (P <0 0 0 1) ;经过糖皮质激素治疗后血清UA水平明显回升 (P <0 0 0 1) ,但治疗前血清UA水平越低则疗效越差 (P <0 0 1、P <0 0 5 )。结论 MS患者血清UA水平降低 ,且与MS的病程、伤残程度、疗效及性别密切相关。UA水平升高可能为激素治疗MS的一个作用机制 相似文献
14.
早期扩髓髓内钉固定治疗合并胸部损伤的股骨干骨折 总被引:2,自引:0,他引:2
目的探讨合并胸部损伤的股骨干骨折早期扩髓及髓内钉固定是否增加并发症及死亡率. 方法采用回顾性对比分析,依据下列标准选择病例(1) 年龄在17~65岁;(2) 必须有胸部损伤[简明损伤定级(AIS)≥2], 且损伤严重度评分(ISS)≥16;(3) 住院时间≥48 h;(4) 病史中无明显影响全身状况的疾病, 如糖尿病, 慢性心、肺、肾功能不全等;(5) 有股骨干骨折, 且进行了扩髓髓内钉固定, 不含钢板、外固定支架或牵引及石膏固定者.并按受伤至手术时间划分为两组, A组为<24 h手术者(早期扩髓组), B组为≥24 h手术者(延期扩髓组),将两组间合并伤情况、ISS、住院时间、ICU时间、并发症、死亡及合并休克情况进行比较. 结果有96例符合上述标准, 其中A组57例, B组39例,经统计学处理, 两组间仅在股骨开放性骨折发生率(A组53%,B组31%,χ2=4.496, P<0.05)、合并休克率(A组51%, B组28%,χ2=4.895, P<0.05 )及住院时间[A组为(17.5±6.5)d, B组为(31.5±9.5)d,t=8.599, P<0.001]上差异有显著性意义和非常显著性意义, 而两组并发症发生率和死亡率等方面比较, 差异无显著性意义(P>0.05). 结论在合并胸部损伤的股骨干骨折中,只要能控制休克,保证生命体征平稳,对股骨干骨折行早期扩髓髓内钉固定不增加患者的并发症发生率及死亡率,并可促进患者早日康复,缩短住院时间. 相似文献
15.
多系统萎缩的临床分型和影像学改变特点分析 总被引:2,自引:0,他引:2
目的探讨多系统萎缩(multiple system atrophy,MSA)的临床表现类型与神经影像学改变新特征(脑桥“十字征”和“壳核裂隙征”)的关系,为临床尽早做出诊断提供依据。方法按照Gilman诊断标准回顾性分析11例MSA患者的临床表现、分型和头颅MRI资料。结果本组诊断为很可能MSA11例,其中橄榄体脑桥小脑萎缩(MSA-C型)8例。2例在发病后3年头颅MRI脑桥“十字征”达Ⅰ期;1例在病后2年达Ⅱ期;3例分别在病后1年、3年、5年达Ⅲ期;另外2例分别在病后2年和7年达Ⅳ期。8例“壳核裂隙征”均为0期。黑质纹状体变性(MSA-P型)2例:1例病后6年脑桥“十字征”0期,“壳核裂隙征”Ⅰ期,另1例发病后9年“壳核裂隙征”Ⅱ期,脑桥“十字征”Ⅳ期。Shy-Drager综合征(MSA-A型)1例:病程5年,MRI检查脑桥“十字征”和“壳核裂隙征”分期均为0期。结论临床表现与头颅MRI检查发现的脑桥“十字征”和“壳核裂隙征”可作为及早识别MSA-C型的神经影像学改变特征,“壳核裂隙征”可作为识别MSA-P型的神经影像学改变特征。 相似文献
16.
17.
P. Cavalla V. Rovei S. Masera M. Vercellino M. Massobrio R. Mutani A. Revelli 《Neurological sciences》2006,27(4):231-239
Abstract The issue of fertility in patients with multiple sclerosis (MS) has not been exhaustively studied. Epidemiological data have
suggested that spontaneous fecundity might be reduced; several endocrine and sexual disturbances potentially interfering with
reproduction have been evidenced in MS patients of both sexes. Moreover, some medical treatments used in MS (e. g., mitoxantrone,
cyclophosphamide) may exert detrimental effects on spermatozoa as well as on oocytes, leading to early impairment of fertility.
This review illustrates the factors potentially interfering with fertility in MS and discusses the therapeutic tools that
may be used to promote fertility in these patients. The safety of hormonal therapies in MS is also examined. The current applications
of assisted reproductive technology (ART) are discussed, including in vitro fertilisation (IVF) techniques. Currently available methods to preserve fertility in patients that undergo cytotoxic treatments
by means of sperm/oocyte cryostorage or by ovarian fragment cryopreservation and autografting are considered. 相似文献
18.
Wallin C.-J. B.; Jacobson S. H.; Leksell L. G. 《Nephrology, dialysis, transplantation》1996,11(11):2269-2275
It has been postulated that patients with chronic renal failure,even in the absence of cardiopulmonary symptoms, accumulateinterstitial pulmonary fluid, which is removed by haemodialysis.To test this hypothesis we used the indocyanine green (ICG)-heavywater double indicator dilution method to measure lung water,cardiac output, and central blood volume in relation to haemodialysis.Ten uraemic patients, without cardiopulmonary symptoms, wereinvestigated at the beginning and end, and 2 h after, a regulardialysis session. A group of 18 surgical patients about to undergoelective abdominal surgery served as controls. Despite normalgas exchange, central blood volume, and cardiac output at thestart of dialysis the mean (SD) lung water was significantlyhigher than in the control group [4.8 (0.9) compared with 3.6(0.7) ml/kg, P<0.001]. There was no correlation between weightgain between sessions of dialysis and the magnitude of lungwater at the start of dialysis. Lung water decreased (P <0.001)to the level of the control group in response to dialysis. Therewas no correlation between weight loss and reduction in lungwater induced by dialysis. In conclusion, we have verified thepresence of subclinical pulmonary oedema which was removed bydialysis in a group of patients with established renal failure.The variations in lung water cannot be explained by hydrostaticmechanisms alone. 相似文献
19.
P. Kiviskk W. Tian S. Fredrikson H. Link M. Sderstrm 《European journal of neurology》1997,4(5):460-467
Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b. 相似文献
20.
G. Van Goethem J.-J. Martin A. Lfgren I. Dehaene P. Tack M. Van Zandycke D. Ververken C. Ceuterick C. Van Broeckhoven 《European journal of neurology》1997,4(5):476-484
We studied 14 patients from three unrelated Belgian pedigrees with a familial mitochondrial disorder and multiple deletions of mitochondrial DNA (mtDNA). In one family with an oculopharyngeal presentation there is a clear autosomal dominant inheritance. Progressive external ophthalmoplegia (PEO), “ragged red fibres” (RRF) and multiple deletions of mtDNA are common to all three families. Therefore a diagnosis of autosomal dominant progressive ophthalmoplegia with multiple deletions of mtDNA (adPEO) was made in one family at least. Our data confirm the previous observations that adPEO is a systemic disorder rather than a pure myopathy. In our pedigrees frequently associated features include axonal peripheral neuropathy, dysphagia, psychiatric illness, and sudden death. Mild ataxia, pes cavus and mitral valve prolapse with associated mitral insufficiency also occur. In some cases onset is atypical with neuropathy, adolescent onset myopathy or psychiatric illness. In such cases the common features of PEO and muscle weakness always complete the clinical phenotype later during the course of the disease. Biochemical studies on mitochondrial fractions prepared from one patient's muscle, revealed no abnormalities of respiratory chain enzyme activities. 相似文献