全文获取类型
收费全文 | 2811篇 |
免费 | 189篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 68篇 |
妇产科学 | 71篇 |
基础医学 | 424篇 |
口腔科学 | 142篇 |
临床医学 | 250篇 |
内科学 | 565篇 |
皮肤病学 | 107篇 |
神经病学 | 340篇 |
特种医学 | 117篇 |
外科学 | 289篇 |
综合类 | 13篇 |
预防医学 | 151篇 |
眼科学 | 32篇 |
药学 | 168篇 |
中国医学 | 8篇 |
肿瘤学 | 240篇 |
出版年
2023年 | 28篇 |
2022年 | 25篇 |
2021年 | 102篇 |
2020年 | 72篇 |
2019年 | 85篇 |
2018年 | 92篇 |
2017年 | 94篇 |
2016年 | 106篇 |
2015年 | 106篇 |
2014年 | 125篇 |
2013年 | 149篇 |
2012年 | 234篇 |
2011年 | 226篇 |
2010年 | 134篇 |
2009年 | 117篇 |
2008年 | 170篇 |
2007年 | 161篇 |
2006年 | 130篇 |
2005年 | 136篇 |
2004年 | 117篇 |
2003年 | 105篇 |
2002年 | 81篇 |
2001年 | 29篇 |
2000年 | 31篇 |
1999年 | 31篇 |
1998年 | 23篇 |
1997年 | 23篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1992年 | 10篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1984年 | 7篇 |
1981年 | 8篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 10篇 |
1971年 | 8篇 |
1970年 | 8篇 |
1968年 | 7篇 |
1967年 | 7篇 |
1966年 | 11篇 |
1965年 | 6篇 |
1957年 | 7篇 |
排序方式: 共有3014条查询结果,搜索用时 187 毫秒
1.
2.
Ronny Redlich Ilona Schneider Nicole Kerkenberg Nils Opel Jonas Bauhaus Verena Enneking Jonathan Repple Elisabeth J. Leehr Dominik Grotegerd Claas Khler Katharina Frster Katharina Dohm Susanne Meinert Tim Hahn Harald Kugel Kathrin Schwarte Christiane Schettler Katharina Domschke Volker Arolt Walter Heindel Bernhard T. Baune Weiqi Zhang Christa Hohoff Udo Dannlowski 《Human brain mapping》2020,41(3):594-604
Epigenetic alterations of the brain‐derived neurotrophic factor (BDNF) gene have been associated with psychiatric disorders in humans and with differences in amygdala BDNF mRNA levels in rodents. This human study aimed to investigate the relationship between the functional BDNF‐Val66Met polymorphism, its surrounding DNA methylation in BDNF exon IX, amygdala reactivity to emotional faces, and personality traits. Healthy controls (HC, n = 189) underwent functional MRI during an emotional face‐matching task. Harm avoidance, novelty seeking and reward dependence were measured using the Tridimensional Personality Questionnaire (TPQ). Individual BDNF methylation profiles were ascertained and associated with several BDNF single nucleotide polymorphisms surrounding the BDNF‐Val66Met, amygdala reactivity, novelty seeking and harm avoidance. Higher BDNF methylation was associated with higher amygdala reactivity (x = 34, y = 0, z = ?26, t(166) = 3.00, TFCE = 42.39, p(FWE) = .045), whereby the BDNF‐Val66Met genotype per se did not show any significant association with brain function. Furthermore, novelty seeking was negatively associated with BDNF methylation (r = ?.19, p = .015) and amygdala reactivity (r = ?.17, p = .028), while harm avoidance showed a trend for a positive association with BDNF methylation (r = .14, p = .066). The study provides first insights into the relationship among BDNF methylation, BDNF genotype, amygdala reactivity and personality traits in humans, highlighting the multidimensional relations among genetics, epigenetics, and neuronal functions. The present study suggests a possible involvement of epigenetic BDNF modifications in psychiatric disorders and related brain functions, whereby high BDNF methylation might reduce BDNF mRNA expression and upregulate amygdala reactivity. 相似文献
3.
4.
Nervensch?digungen als Begleitverletzungen bei Monteggia-Frakturen sind selten und betreffen meistens den N. radialis. üblicherweise
kommt es bei frischen Frakturen zu einer spontanen neurologischen Remission, nachdem der Radiuskopf wieder reponiert wurde.
Im vorliegenden Fall erlitt ein heute 33-j?hriger Mann eine Parese des N. interosseus posterior 27 Jahre nach einer Monteggia-Fraktur,
wobei der Radiuskopf in luxierter Stellung verblieb. Nach einem Bagatelltrauma am Handgelenk beim Federballspielen kam es
zu einer L?hmung der Handgelenk- und Fingerstreckmuskulatur. Eine konservative Behandlung mittels intensiver Physiotherapie
blieb auch nach 4 Monaten erfolglos. Daraufhin wurde der Nerv exploriert. Der Profundusast zeigte sich dabei narbig adh?rent
im Bereich einer beengenden und verdickten Frohse-Arkade. Anschlie?end erfolgte eine Narbenl?sung sowie Spaltung der Arkade,
der Radiuskopf wurde im ursprünglichen verrenkten Zustand belassen. Eine v?llige Erholung des l?dierten Nerven war 9 Monate
postoperativ erreicht. 相似文献
5.
Bernd Huber Ines Hauser Verena Horstmann Gabi Jokeit Sylvia Liem Theodor May Thomas Meinert Enrique Robertson Heide Schorlemmer Wolfgang Wagner Michael Seidel 《Seizure》2007,16(1):35-42
This study was designed to describe the course of epilepsy (in terms of seizure frequency) and to assess the variables (antiepileptic therapy regimens and others) correlated to improvement. Seizure frequency (categories: seizure free, more than one seizure/year, monthly seizures, weekly seizures and daily seizures) and antiepileptic medication were retrospectively compared between 1992 and 2002 in a large cohort of 550 inpatients with chronic epilepsy and different degrees of intellectual disability or multiple handicaps. RESULTS: Seizure frequency decreased significantly (p<0.001). 218 of the 394 patients (55.3%) not seizure free in 1992 improved (changed into a better frequency category). The improvement rate was marginally higher in patients who had undergone a medication change (p=0.08). A high seizure frequency in 1992 (p=0.016) and older age (p=0.006), but not epilepsy syndrome or degree of intellectual disability, were predictors for improvement (stepwise logistic regression analysis). 56.4% of the improved patients were on combinations of two AEDs (17.4%, monotherapy; 20.2%, triple therapy). The most frequent therapy regimens in the improved patients were lamotrigine/valproate (48 patients), carbamazepine/phenobarbital (21) and carbamazepine only (19). Lamotrigine/valproate was effective in all kinds of epileptic syndromes. Most patients on lamotrigine had serum concentrations above 10microg/ml, approximately one half had dosages above 200mg/day. The rate of seizure freedom increased from 28.4 to 37.6%. The 84% of the patients seizure free in 1992 remained seizure free. Predictors for seizure freedom in 2002 were higher age (stepwise logistic regression, p<0.0005) and seizure freedom in 1992 (p<0.0005). CONCLUSIONS: Substantial improvement can be achieved even in intellectually disabled patients with chronic epilepsy. Although the rate of seizure freedom is reduced in comparison with a non-ID population, once seizure freedom has been achieved it is most likely to continue. For a majority of this patient population, monotherapy may not be sufficient. Lamotrigine/valproate appears to be a major therapeutic innovation. 相似文献
6.
Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy. 相似文献
7.
8.
Pneumonia is one of the leading causes of morbidity, hospitalization, and mortality in both industrialized and developing countries. In particular, pulmonary infections acquired in the community, and pneumonias arising in the hospital setting, represent a major medical and economic problem and thus a continuous challenge to health care. For the radiologist, it is important to understand that community-acquired pneumonia (CAP) and nosocomial pneumonia (NP) share a number of characteristics, but should, in many respects be regarded as separate entities. CAP and NP arise in different populations, host different spectra of causative pathogens, and pose different challenges to both the clinician and the radiologist. CAP is generally seen in outpatients, is most frequently caused by Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Chlamydia, and its radiologic diagnosis is relatively straightforward. NP, in contrast, develops in the hospital setting, is commonly caused by gram-negative bacteria, and may generate substantial problems for the radiologist. Overall, both for CAP and NP, imaging is an integral component of the diagnosis, important for classification and differential diagnosis, and helpful for follow-up. 相似文献
9.
Kathrin Scherer Wolfgang Studer Verena Figueiredo Andreas J Bircher 《Annals of allergy, asthma & immunology》2006,96(3):497-500
BACKGROUND: Blue dyes used for lymphatic mapping in sentinel lymph node biopsy cause intraoperative anaphylactic reactions in up to 2.7% of patients. With increasing implementation of this technique, the incidence of anaphylaxis to these dyes can be expected to increase. In the literature, the chemically often unrelated and inconsistently designated dyes have been confused, adding to other inconsistencies in the nomenclature. OBJECTIVE: To demonstrate the nomenclature, chemical and physiologic differences, and allergenicity of the various blue dyes used in a medical context. METHODS: We describe a patient with an intraoperative grade IV anaphylactic reaction to isosulfan blue. Immediate-type hypersensitivity was proved by positive skin test reactions and CD63 expression to isosulfan blue and cross-reactivity to patent blue V. RESULTS: A review of the literature clarified the exact nomenclature of the blue dyes and the possible pitfalls of confusing nomenclature in the context of structurally closely related dyes with different allergenic properties. For the detection of type I hypersensitivity, intracutaneous tests are valuable tools. An IgE-mediated mechanism has been shown recently. In most cases, sensitization exists without known previous exposure in a medical context. This may be due to the widespread use of such dyes in objects of everyday life. Preoperative antiallergic medication use does not prevent anaphylactic reactions but apparently reduces their severity. CONCLUSION: For better comparison and precision, the Chemical Abstracts Service number of the respective dye should always be given. 相似文献
10.