全文获取类型
收费全文 | 249篇 |
免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 4篇 |
妇产科学 | 32篇 |
基础医学 | 70篇 |
临床医学 | 20篇 |
内科学 | 34篇 |
神经病学 | 25篇 |
特种医学 | 1篇 |
外科学 | 17篇 |
综合类 | 7篇 |
预防医学 | 11篇 |
眼科学 | 1篇 |
药学 | 23篇 |
中国医学 | 1篇 |
肿瘤学 | 4篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 12篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 4篇 |
2002年 | 12篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1994年 | 2篇 |
1991年 | 3篇 |
1985年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1967年 | 2篇 |
1966年 | 4篇 |
1962年 | 2篇 |
1960年 | 2篇 |
1955年 | 2篇 |
1944年 | 2篇 |
1942年 | 4篇 |
1941年 | 2篇 |
1939年 | 4篇 |
1937年 | 2篇 |
1936年 | 2篇 |
1933年 | 4篇 |
1932年 | 2篇 |
1930年 | 2篇 |
1929年 | 5篇 |
1927年 | 5篇 |
1926年 | 5篇 |
1925年 | 6篇 |
1924年 | 2篇 |
1923年 | 9篇 |
1922年 | 7篇 |
排序方式: 共有251条查询结果,搜索用时 15 毫秒
101.
B. Koletzko H. Demmelmair V. Grote C. Hellmuth F. Kirchberg O. Uhl M. Weber C. Prell 《Monatsschrift für Kinderheilkunde》2016,164(2):114-121
The early nutrition from conception to early childhood has imprinting or programming effects on later health and disease risks. Rapid weight gain in fetal life and early childhood increases the risk of later obesity, diabetes and other non-communicable diseases (NCD). In observational cohort studies rapid weight gain from birth to 2 years old was associated with an increased risk of obesity up to adulthood. Breastfeeding is associated with less rapid weight gain in infancy than conventional infant formula nutrition. Several meta-analyses of observational studies found that breastfeeding was associated with an approximately 12–24?% reduction in the risk of obesity in later life. We investigated the early protein hypothesis, which proposes that a high protein intake in infancy leads to increased concentrations of insulinogenic amino acids, the growth factors insulin and insulin-like growth factor-1 (IGF-1) as well as greater weight gain and later obesity. The hypothesis was tested in a double blind randomized clinical trial involving 1678 term infants who received conventional infant and follow-on formulae with higher protein content or with reduced protein content during the first year of life. The reduced protein diet led to significantly reduced body weight, weight-for-length and body mass index (BMI) up to the age of 2 years and to a 2.4–2.9-fold reduction of obesity at 6 years old compared to conventional bottle feeding formulae. We concluded that infant feeding has powerful long-term programming effects, with very large effect sizes on obesity in early school age. Breastfeeding should be actively promoted, protected and supported. Infants not exclusively breastfed should receive infant formulae with reduced protein content. Unmodified cows’ milk contains three times as much protein as human milk and should be avoided as a drink in infancy. 相似文献
102.
Klaus-Martin Krönke Karsten Mueller Angela D. Friederici Hellmuth Obrig 《Cortex; a journal devoted to the study of the nervous system and behavior》2013
Meaningful gestures enhance speech comprehensibility. However, their role during novel-word acquisition remains elusive. Here we investigate how meaningful versus meaningless gestures impact on novel-word learning and contrast these conditions to a purely verbal training. After training, neuronal processing of the novel words was assessed by blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI), disclosing that networks affording retrieval differ depending on the training condition. Over 3 days participants learned pseudowords for common objects (e.g., /klira/ -cap). For training they repeated the novel word while performing (i) an iconic, (ii) a grooming or (iii) no gesture. For the two conditions involving gestures, these were either actively repeated or passively observed during training. Behaviorally no substantial differences between the five different training conditions were found while fMRI disclosed differential networks affording implicit retrieval of the learned pseudowords depending on the training procedure. Most notably training with actively performed iconic gestures yielded larger activation in a semantic network comprising left inferior frontal (BA47) and inferior temporal gyri. Additionally hippocampal activation was stronger for all trained compared to unknown pseudowords of identical structure. The behavioral results challenge the generality of an ‘enactment-effect’ for single word learning. Imaging results, however, suggest that actively performed meaningful gestures lead to a deeper semantic encoding of novel words. The findings are discussed regarding their implications for theoretical accounts and for empirical approaches of gesture-based strategies in language (re)learning. 相似文献
103.
Elena Winheim Tabea Eser Flora Deák Mohamed I. M. Ahmed Olga Baranov Linus Rinke Katharina Eisenächer Antonio Santos-Peral Hadi Karimzadeh Michael Pritsch Clemens Scherer Maximilian Muenchhoff Johannes C. Hellmuth Michael von Bergwelt-Baildon Laura Olbrich Michael Hoelscher Andreas Wieser Inge Kroidl Simon Rothenfusser Christof Geldmacher Anne B. Krug 《European journal of immunology》2023,53(3):2250090
Dysregulation of the myeloid cell compartment is a feature of severe disease in hospitalized COVID-19 patients. Here, we investigated the response of circulating dendritic cell (DC) and monocyte subpopulations in SARS-CoV-2 infected outpatients with mild disease and compared it to the response of healthy individuals to yellow fever vaccine virus YF17D as a model of a well-coordinated response to viral infection. In SARS-CoV-2-infected outpatients circulating DCs were persistently reduced for several weeks whereas after YF17D vaccination DC numbers were decreased temporarily and rapidly replenished by increased proliferation until 14 days after vaccination. The majority of COVID-19 outpatients showed high expression of CD86 and PD-L1 in monocytes and DCs early on, resembling the dynamic after YF17D vaccination. In a subgroup of patients, low CD86 and high PD-L1 expression were detected in monocytes and DCs coinciding with symptoms, higher age, and lower lymphocyte counts. This phenotype was similar to that observed in severely ill COVID-19 patients, but less pronounced. Thus, prolonged reduction and dysregulated activation of blood DCs and monocytes were seen in a subgroup of symptomatic non-hospitalized COVID-19 patients while a transient coordinated activation was characteristic for the majority of patients with mild COVID-19 and the response to YF17D vaccination. 相似文献
104.
Peter Nielsen Bernd Dresow Roland Fischer Hellmuth C. Heinrich 《Archives of toxicology》1990,64(5):420-422
After oral administration of 500 mg KFe[Fe(CN)6] labelled with59Fe either in the ferric or ferrous position and with14C in the cyanide group only 0.22% of the FeII and <0.04% of the FeIII were absorbed in three male volunteers. Only 2 mg non-complex bound relabelled cyanide (0.03 mg CN-/kg body wt) were absorbed from 500 mg [14C]KFeHCF, which is about a factor of 20–100 below the lethal dose in humans (0.5–3.5 mg CN-/kg body wt). Therefore, iron(III) hexacyanoferrates(II) can be considered as safe antidotes, i.e. for inhibiting the intestinal absorption of radiocaesium or for accelerating the excretion of already absorbed134/137Cs in the case of a severe nuclear accident. 相似文献
105.
106.
107.
Semantic memory retrieval: cortical couplings in object recognition in the N400 window 总被引:1,自引:0,他引:1
Supp GG Schlögl A Fiebach CJ Gunter TC Vigliocco G Pfurtscheller G Petsche H 《The European journal of neuroscience》2005,21(4):1139-1143
To characterize the regional changes in neuronal couplings and information transfer related to semantic aspects of object recognition in humans we used partial-directed EEG-coherence analysis (PDC). We examined the differences of processing recognizable and unrecognizable pictures as reflected by changes in cortical networks within the time-window of a determined event-related potential (ERP) component, namely the N400. Fourteen participants performed an image recognition task, while sequentially confronted with pictures of recognizable and unrecognizable objects. The time-window of N400 as indicative of object semantics was defined from the ERP. Differences of PDC in the beta-band between these tasks were represented topographically as patterns of electrical couplings, possibly indicating changing degrees of functional cooperation between brain areas. Successful memory retrieval of picture meaning appears to be supported by networks comprising left temporal and parietal regions and bilateral frontal brain areas. 相似文献
108.
Dr. med. Karl Hellmuth 《Archives of gynecology and obstetrics》1926,127(2-3):293-361
Die Arbeit berichtet über Untersuchungen, die die Verteilung des Lipoidkomplexes und seiner wichtigsten Komponenten (Gesamtcholesterin, d. h. freien und Esteranteil, Gesamtfettsäuren und Lipoidphosphor bzw. Lecithin) im mütterlichen und fetalen Blut unter normalen und pathologischen Verhältnissen (Schwangerschaftsnierenerkrankungen und Eklampsien) betreffen, und sie enthält einen Anhang über Lipaseuntersuchungen in diesen beiden Kreisläufen), 相似文献
109.
Two sets of polymer blends have been prepared by mixing solutions or melts of polystyrene with polybutene-1(poly(1-ethylethylene)), cellulose acetate, poly(methyl methacrylate), polyisobutylene, atactic polypropylene, poly(vinyl chloride), high pressure polyethylene, and of poly(vinyl chloride) with high pressure polyethylene, ABS, poly(vinylidene chloride), poly(vinyl acetate), vinyl chloride/vinyl acetate copolymer. The phase structure of these blends was analysed by microscopic and differential calorimetric measurements and by determination of the turbidity of the films. Phase diagrams were prepared from the glass transition temperatures and melting points taken from DSC curves. In this analysis all systems show a distinct phase separation ensuing from incompatibility. The only exception is the blend: poly(vinyl chloride) + vinyl chloride/vinyl acetate copolymer. 相似文献
110.
Hellmuth Lilienthal Hermann H. Dieter Jürgen Hölzer Michael Wilhelm 《International journal of hygiene and environmental health》2017,220(4):766-775
The detection of perfluoroalkyl substances (PFAS) in surface and drinking water from various countries raised the attention to the presence of these chemicals in environmental probes and led to several regulatory actions to limit exposure in human beings. There was particular concern about perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), due to their former wide-spread use. Recently, several institutions published revisions of former regulatory or recommended maximum concentrations in drinking water and food, which are markedly lower than the former values. The present short overview describes the current regulations for PFAS and compares them with the outcome of several experimental studies in laboratory animals at low-level exposure to PFOA and PFOS. In addition, regulations for short-chain PFAS are presented which, due to lack of toxicological information, are evaluated according to the concepts of Threshold of Toxicological Concern (TTC) or the Health-related Indication Values (HRIV). 相似文献