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1.
Nanotechnology ; 34(26)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-36758234

RESUMO

The fabrication and characterization of steep slope transistor devices based on low-dimensional materials requires precise electrostatic doping profiles with steep spatial gradients in order to maintain maximum control over the channel. In this proof-of-concept study we present a versatile graphene heterostructure platform with three buried individually addressable gate electrodes. The platform is based on a vertical stack of embedded titanium and graphene separated by an intermediate oxide to provide an almost planar surface. We demonstrate the functionality and advantages of the platform by exploring transfer and output characteristics at different temperatures of carbon nanotube field-effect transistors with different electrostatic doping configurations. Furthermore, we back up the concept with finite element simulations to investigate the surface potential. The presented heterostructure is an ideal platform for analysis of electrostatic doping of low-dimensional materials for novel low-power transistor devices.

2.
Plant Phenomics ; 2020: 4635153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33313557

RESUMO

Drought is a recurring phenomenon that puts crop yields at risk and threatens the livelihoods of many people around the globe. Stay-green is a drought adaption phenotype found in sorghum and other cereals. Plants expressing this phenotype show less drought-induced senescence and maintain functional green leaves for longer when water limitation occurs during grain fill, conferring benefits in both yield per se and harvestability. The physiological causes of the phenotype are postulated to be water saving through mechanisms such as reduced canopy size or access to extra water through mechanisms such as deeper roots. In sorghum breeding programs, stay-green has traditionally been assessed by comparing visual scores of leaf senescence either by identifying final leaf senescence or by estimating rate of leaf senescence. In this study, we compared measurements of canopy dynamics obtained from remote sensing on two sorghum breeding trials to stay-green values (breeding values) obtained from visual leaf senescence ratings in multienvironment breeding trials to determine which components of canopy development were most closely linked to the stay-green phenotype. Surprisingly, canopy size as estimated using preflowering canopy parameters was weakly correlated with stay-green values for leaf senescence while postflowering canopy parameters showed a much stronger association with leaf senescence. Our study suggests that factors other than canopy size have an important role in the expression of a stay-green phenotype in grain sorghum and further that the use of UAVs with multispectral sensors provides an excellent way of measuring canopy traits of hundreds of plots grown in large field trials.

3.
Allergy ; 73(5): 1101-1109, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29159975

RESUMO

BACKGROUND: The Global Allergy and Asthma European Network (GA2 LEN) Taskforce has requested more data on correlations between various patient-reported outcomes (PROs) in clinical trials on allergy. We compared three tools-the Rhinitis Control Assessment Test (RCAT), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and Rhinitis Total Symptom Score (RTSS)-to determine whether the RCAT alone is a sufficient primary outcome parameter in clinical trials on allergic rhinoconjunctivitis. METHODS: In two double-blind, placebo-controlled immunotherapy studies, 33 patients allergic to grass pollen and 94 to birch pollen completed two questionnaires (RCAT and RQLQ) and kept their own symptom diary from which the RTSS was calculated. RESULTS: Upon comparing RCAT and RQLQ results, we found strong correlations of r = -0.871 for grass pollen-allergic patients and r = -0.795 for birch pollen-allergic patients. The comparison between RCAT and RTSS results showed a strong correlation of r = -0.811 (grass pollen-allergic patients) and a moderate correlation of r = -0.539 (birch pollen-allergic patients). In the RCAT, 69.7% of grass pollen-allergic patients and 45.7% of birch pollen-allergic patients receiving guideline-concordant therapy were regarded as having insufficiently controlled symptoms. CONCLUSION: The strong correlations suggest that the RCAT alone is equivalent to the RQLQ with respect to patients' symptom control and quality of life. Patients with uncontrolled symptoms can be identified using the RCAT. Hence, the physician can decide whether symptomatic therapy can be intensified or allergy immunotherapy should be administered.


Assuntos
Conjuntivite Alérgica/prevenção & controle , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Rinite Alérgica Sazonal/prevenção & controle , Rinite Alérgica/prevenção & controle , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imunoterapia Sublingual , Inquéritos e Questionários
4.
Anim Cogn ; 20(6): 1093-1106, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28831579

RESUMO

There is a long-standing debate as to whether social or physical environmental aspects drive the evolution and development of cognitive abilities. Surprisingly few studies make use of developmental plasticity to compare the effects of these two domains during development on behaviour later in life. Here, we present rearing effects on the development of learning abilities and social behaviour in the jumping spider Marpissa muscosa. These spiders are ideally suited for this purpose because they possess the ability to learn and can be reared in groups but also in isolation without added stress. This is a critical but rarely met requirement for experimentally varying the social environment to test its impact on cognition. We split broods of spiders and reared them either in a physically or in a socially enriched environment. A third group kept under completely deprived conditions served as a 'no-enrichment' control. We tested the spiders' learning abilities by using a modified T-maze. Social behaviour was investigated by confronting spiders with their own mirror image. Results show that spiders reared in groups outperform their conspecifics from the control, i.e. 'no-enrichment', group in both tasks. Physical enrichment did not lead to such an increased performance. We therefore tentatively suggest that growing up in contact with conspecifics induces the development of cognitive abilities in this species.


Assuntos
Comportamento Animal , Aprendizagem , Comportamento Social , Aranhas/fisiologia , Agressão , Animais , Aprendizagem por Associação , Cognição , Feminino , Masculino , Reversão de Aprendizagem , Meio Social
5.
Vet Microbiol ; 160(1-2): 251-5, 2012 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-22673319

RESUMO

Minimal inhibitory concentrations (MIC) and growth behaviour in ZnO supplemented media were determined by the broth micro dilution method against 75 reference strains. No clear clustering according to bacterial group was observed, but 10 of 11 Lactobacillaceae strains showed high zinc resistance (≥520 µg mL(-1)). Enterobacterial strains showed high (6/11) to medium resistance (5/11). The Clostridia and Bacteroidaceae strains exhibited a diverse range of MIC. The results of this study show that zinc resistance of commensal intestinal bacteria cannot be grouped according to their taxonomic origin and therefore, the antibacterial activity of ZnO in the intestine of farm animals cannot be generalized.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Intestinos/microbiologia , Óxido de Zinco/farmacologia , Animais , Bactérias/efeitos dos fármacos , Bacteroidaceae/efeitos dos fármacos , Clostridium/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Lactobacillaceae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Suínos
7.
Postgrad Med ; 59(5): 179-88, 1976 May.
Artigo em Inglês | MEDLINE | ID: mdl-4783

RESUMO

The physician who understands the pathophysiology of angina pectoris can apply rational therapeutic measures based on an appreciation of the determinants of myocardial oxygen supply and demand. Most patients with angina secondary to coronary atherosclerosis can be treated conservatively using a systematic approach that includes correction or removal of underlying causes or precipitating factors and the judicious use of sublingual nitroglycerin. In patients with more resistant angina, use of oral or topical nitroglycerin or sublingual isosorbide dinitrite as well as propranolol can be advised. Aortocoronary bypass surgery can offer significant improvement in carefully selected patients with frequent angina poorly controlled by medical therapy. The most important consideration in the treatment of angina is protection of coronary blood flow reserve by primary prevention of the atherosclerotic process itself. All individuals from families prone to coronary artery disease should be evaluated for alterable risk factors, the most important being cigarette smoking, hypertension, and hypercholesterolemia. Considering the high risk of unheralded sudden death in previously asymptomatic patients with coronary atherosclerosis, angina can, in a sense, be considered a fortunate harbinger of coronary stenosis, identifying candidates for secondary preventive measures aimed at retarding the progression of vascular disease. More importantly, angina serves as an index for detecting families at high risk of coronary artery disease, in whom early application of primary prevention may afford a more promising outlook.


Assuntos
Angina Pectoris/terapia , Antagonistas Adrenérgicos beta/uso terapêutico , Angina Pectoris/diagnóstico , Angina Pectoris/etiologia , Doença das Coronárias/complicações , Diagnóstico Diferencial , Glicosídeos Digitálicos/uso terapêutico , Etanol/uso terapêutico , Terapia por Exercício , Humanos , Miocárdio/metabolismo , Nitroglicerina/uso terapêutico , Consumo de Oxigênio , Dor/diagnóstico
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