全文获取类型
收费全文 | 7371篇 |
免费 | 410篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 149篇 |
妇产科学 | 123篇 |
基础医学 | 1463篇 |
口腔科学 | 111篇 |
临床医学 | 617篇 |
内科学 | 1235篇 |
皮肤病学 | 192篇 |
神经病学 | 995篇 |
特种医学 | 411篇 |
外国民族医学 | 1篇 |
外科学 | 840篇 |
综合类 | 46篇 |
预防医学 | 322篇 |
眼科学 | 125篇 |
药学 | 566篇 |
中国医学 | 11篇 |
肿瘤学 | 520篇 |
出版年
2021年 | 65篇 |
2020年 | 56篇 |
2019年 | 107篇 |
2018年 | 119篇 |
2017年 | 93篇 |
2016年 | 162篇 |
2015年 | 180篇 |
2014年 | 200篇 |
2013年 | 258篇 |
2012年 | 398篇 |
2011年 | 416篇 |
2010年 | 281篇 |
2009年 | 243篇 |
2008年 | 389篇 |
2007年 | 402篇 |
2006年 | 399篇 |
2005年 | 383篇 |
2004年 | 346篇 |
2003年 | 376篇 |
2002年 | 384篇 |
2001年 | 91篇 |
2000年 | 111篇 |
1999年 | 123篇 |
1998年 | 123篇 |
1997年 | 86篇 |
1996年 | 68篇 |
1995年 | 62篇 |
1994年 | 57篇 |
1993年 | 62篇 |
1992年 | 68篇 |
1991年 | 54篇 |
1990年 | 66篇 |
1989年 | 56篇 |
1988年 | 60篇 |
1987年 | 44篇 |
1985年 | 52篇 |
1984年 | 31篇 |
1983年 | 43篇 |
1982年 | 39篇 |
1981年 | 40篇 |
1980年 | 35篇 |
1979年 | 52篇 |
1978年 | 39篇 |
1977年 | 38篇 |
1976年 | 42篇 |
1974年 | 33篇 |
1972年 | 29篇 |
1955年 | 44篇 |
1954年 | 36篇 |
1932年 | 41篇 |
排序方式: 共有7802条查询结果,搜索用时 171 毫秒
1.
Noreen M. Walsh Heinz Kutzner Luis Requena Lorenzo Cerroni 《Journal of cutaneous pathology》2019,46(9):698-708
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field. 相似文献
2.
3.
Thomas Asendorf Robin Henderson Heinz Schmidli Tim Friede 《Statistics in medicine》2019,38(9):1503-1528
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis. 相似文献
4.
Victoria Alegría‐Landa Heinz Kutzner Luis Requena 《Journal of cutaneous pathology》2019,46(11):867-871
Carcinosarcomas are biphasic tumors composed of admixed malignant epithelial and mesenchymal components. Numerous terms have been used to name such neoplasms; therefore, terminological confusion is frequent. Most examples of carcinosarcomas are encountered in non‐cutaneous sites, with approximately 100 cases of cutaneous carcinosarcomas reported so far in the English literature. Although different theories have been suggested to explain the occurrence of these peculiar neoplasms, histogenetic mechanisms should be better hypothesized depending on each individual case. Even though prognosis tends to be related to the specific components of the lesion, especially the epithelial one, it seems that cases of cutaneous localization usually have a better outcome. We report an exceedingly rare case of syringocystadenocarcinoma papilliferum which showed an atypical stroma with sarcomatoid appearance, and highlight that the terminology used for this spectrum of lesions is disorganized and confusing. 相似文献
5.
EEG in Creutzfeldt-Jakob disease. 总被引:2,自引:0,他引:2
Electroecenphalography (EEG) is an integral part of the diagnostic process in patients with Creutzfeldt-Jakob disease (CJD). The EEG has therefore been included in the World Health Organisation diagnostic classification criteria of CJD. In sporadic CJD (sCJD), the EEG exhibits characteristic changes depending on the stage of the disease, ranging from nonspecific findings such as diffuse slowing and frontal rhythmic delta activity (FIRDA) in early stages to disease-typical periodic sharp wave complexes (PSWC) in middle and late stages to areactive coma traces or even alpha coma in preterminal EEG recordings. PSWC, either lateralized (in earlier stages) or generalized, occur in about two-thirds of patients with sCJD, with a positive predictive value of 95%. PSWC occur in patients with methionine homozygosity and methionine/valine heterozygosity but only rarely in patients with valine homozygosity at codon 129 of the prion protein gene. PSWC tend to disappear during sleep and may be attenuated by sedative medication and external stimulation. Seizures are an uncommon finding, occurring in less than 15% of patients with sCJD. In patients with iatrogenic CJD, PSWC usually present with more regional EEG findings corresponding to the site of inoculation of the transmissible agent. In genetic CJD, PSWC in its typical form are uncommon, occurring in about 10%. No PSWC occur in EEG recordings of patients with variant CJD. 相似文献
6.
Anne S Hinckers Manfred Laucht Martin H Schmidt Karl F Mann Gunter Schumann Marc A Schuckit Andreas Heinz 《Neuropsychopharmacology》2006,60(3):282-287
BACKGROUND: A low level of response to alcohol has been associated with both the genetic constitution of the regulatory region (SLC6A4) of the human serotonin (5-hydroxytryptamine, 5-HT) transporter (5-HTT) and with future alcohol intake and an increased risk for alcoholism. To date, all studies of relevant polymorphisms have been carried out in populations in the United States. METHODS: Data were extracted from a subset (n = 243) of a cohort of children who have been observed since birth through evaluation of the family history of alcoholism and psychosocial risk influences. At age 16 years, the response to alcohol was assessed with the Self-Rating of the Effects of Alcohol (SRE) questionnaire, and the average amount of alcohol intake per month was assessed during the prior 6 months. Additional variables that were measured included the 5-HTT genotype, externalizing behavior, and sociodemographic variables, such as gender and age. RESULTS: The level of response to alcohol was significantly lower among carriers of two long alleles of the 5-HTT regulatory region compared with carriers of one or two short alleles (Mann-Whitney U = 5225.0, p = .005). In a multiple regression analysis, the level of response to alcohol and externalizing behavior but not psychosocial factors significantly predicted the average amount of alcohol intake per month. CONCLUSIONS: This study demonstrates that, independent of the assessed psychosocial variables, the 5-HTT genotype correlated with the level of response to alcohol and predicted alcohol intake among 16-year-old adolescents. 相似文献
7.
8.
Priv.-Doz. Dr. Rüdiger Dissmann Joachim Schröder MD PhD Prof. Dr. med. Heinz Völler Prof. Dr. med. Steffen Behrens 《Clinical research in cardiology》2006,95(4):241-243
Summary During pacemaker implantation in a patient with permanent atrial fibrillation, it remained impossible to advance a passive
fixation lead with fins through the right atrium. However, a lead with a retractable screw easily passed the right atrium
and was positioned in the right ventricle. Transesophageal echocardiography revealed an extensive net–like perforated Eustachian
valve within the right atrium that had caused entrapment of the anchor fins during lead implantation. Remnants of embryonal
structures within the right atrium should be considered a rare possible barrier during pacemaker implantation. 相似文献
9.
Tick-borne encephalitis (TBE) virus is an important human pathogenic flavivirus that is endemic in Europe and Asia. The disease can be effectively prevented by inactivated vaccines and vaccination breakthroughs (VBTs) are rare. We investigated the characteristics of antibody responses in such VBTs in comparison to those in unvaccinated TBE patients. In contrast to the unvaccinated controls, most of the VBTs displayed a delayed IgM antibody response and had high avidity and strongly neutralizing antibodies already in the first sample taken upon hospitalization. The antibody profile of these patients therefore had the characteristics of an anamnestic immune response. In the VBTs analyzed, immunological priming and memory were apparently not sufficient or fast enough to prevent the disease. 相似文献
10.