Band structure of Si/Ge core-shell nanowires along [110] direction modulated by external uniaxial strain

Strain modulated electronic properties of Si/Ge core-shell nanowires along [110] direction were reported based on first principles density-functional theory calculations. Particularly, the energy dispersion relationship of the conduction/valence band was explored in detail. At the {\Gamma} point, the energy levels of both bands are significantly altered by applied uniaxial strain, which results in an evident change of band gap. In contrast, for the K vectors far away from {\Gamma}, the variation of the conduction/valence band with strain is much reduced. In addition, with a sufficient tensile strain (~1%), the valence band edge (VBE) shifts away from {\Gamma}, which indicates that the band gap of the Si/Ge core-shell nanowires experiences a transition from direct to indirect. Our studies further showed that effective masses of charge carriers can be also tuned by the external uniaxial strain. The effective mass of the hole increases dramatically with a tensile strain, while strain shows a minimal effect on tuning the effective mass of the electron. Finally, the relation between strain and the conduction/valence band edge is discussed thoroughly in terms of site-projected wave-function characters.Comment: 3 tables, 7 figures, Accepted by J. Phys. Condens. Matte

Um cenário de balanço do carbono para Áreas de Preservação Permanentes em mesorregiões leiteiras usando SIG e dados de sensoriamento remoto.

O objetivo deste trabalho foi mapear algumas categorias de Áreas de Preservação Permanentes (APP), com base no Código Florestal de 1965, destinadas à recuperação por regeneração natural de florestas semidecíduas nas mesorregiões Zona da Mata e Campo das Vertentes, Minas Gerais, e a partir disto estabelecer qual é o impacto do emprego das APP?s sobre as áreas de pastagens e subsequente sequestro de carbono. Assim, o cenário de carbono fixo pelas florestas naturais e seu balanço foi considerado como um importante fator para a manutenção de ecossistemas naturais, que posteriormente poderá ser comparado com cenários para o novo código florestal. A partir das informações altimétricas de modelos digitais de elevação (MDE), foi possível extrair dados morfométricos e morfológicos para estimar a APP. Foram utilizadas imagens MODIS / Terra para a extração de áreas de pastagens com o uso de índices de vegetação NDVI para o cruzamento com as APP?s estimadas. Num cenário linear e determinístico de implantação das APP?s em substituição às áreas de pastagens haveria a retração dessas áreas ou impacto de aproximadamente 12% na produção de leite do Campo das Vertentes e 21,5% na produção de leite da Zona da Mata, com subsequente fixação de 48 milhões de toneladas de carbono até o clímax florestal, quando da implantação de florestas semideciduais, e com balanço positivo de 2 ton/ha/ano de carbono fixo, enquanto a pecuária produz 1 ton/ha/ano, se bem manejadas, revelando-se equilíbrio

Theoretical Modeling of Low-Energy Electronic Absorption Bands in Reduced Cobaloximes

The reduced Co^I states of cobaloximes are powerful nucleophiles that play an important role in the hydrogen-evolving catalytic activity of these species. In this work we analyze the low-energy electronic absorption bands of two cobaloxime systems experimentally and use a variety of density functional theory and molecular orbital ab initio quantum chemical approaches. Overall we find a reasonable qualitative understanding of the electronic excitation spectra of these compounds but show that obtaining quantitative results remains a challenging task

A non-recurrent inferior laryngeal nerve in a man undergoing thyroidectomy: a case report

<p>Abstract</p> <p>Introduction</p> <p>A non-recurrent variant of the inferior laryngeal nerve has been seldom reported. These reports are mostly based on cadaveric dissection studies or large chart review studies in which the emphasis is placed on the determination of the frequency of the variation, and not on the clinical appearance of this variant. We graphically describe the intraoperative identification of a non-recurrent inferior laryngeal nerve.</p> <p>Case Presentation</p> <p>A 44-year old Caucasian man was referred to the Head and Neck Surgery Outpatient Clinic with the diagnosis of a nodular mass in his left thyroid lobe that had been growing for one year. A fine needle aspiration puncture was compatible with thyroid papillary cancer. It was decided that the patient should undergo total thyroidectomy. During surgery, a non-recurrent right inferior laryngeal nerve was noted. This nerve emanated from the right vagus nerve, entering the larynx 3 cm after its origin. The nerve did not show a recurrent course. The nerve on the left side had a normal configuration. The surgery and post-operative period were uneventful, and the patient had no change in his voice.</p> <p>Conclusion</p> <p>This paper allows those interested to become acquainted with the normal intraoperative appearance of a non-recurrent inferior laryngeal nerve. This will undoubtedly be of significance for all of those performing invasive diagnostic and surgical procedures in the neck and upper thoracic regions, in order to minimize the risk of iatrogenic injury to this nerve. This is of extreme importance, since a unilateral lesion of this nerve may result in permanent hoarseness, and a bilateral lesion may lead to aphonia and life-threatening dyspnea.</p

The Somatic Reproductive Tissues of C. elegans Promote Longevity through Steroid Hormone Signaling

Removal of the germ cells of C. elegans extends lifespan in part because signals from the somatic reproductive tissues activate the nuclear hormone receptor DAF-12

Galactose epimerase deficiency: lessons from the GalNet registry.

BACKGROUND Galactose epimerase (GALE) deficiency is a rare hereditary disorder of galactose metabolism with only a few cases described in the literature. This study aims to present the data of patients with GALE deficiency from different countries included through the Galactosemia Network to further expand the existing knowledge and review the current diagnostic strategy, treatment and follow-up of this not well characterized entity. METHODS Observational study collecting medical data from December 2014 to April 2022 of 22 not previously reported patients from 14 centers in 9 countries. Patients were classified as generalized or non-generalized based on their genotype, enzyme activities in different tissues and/or clinical picture and professional judgment of the treating physician. RESULTS In total 6 patients were classified as generalized and 16 as non-generalized. In the generalized group, acute neonatal illness was reported in 3, cognitive and developmental delays were present in 5 and hearing problems were reported in 3. Four generalized patients were homozygous for the genetic variant NM_001008216.2:c.280G > A (p.Val94Met). In the non-generalized group, no clearly related symptoms were found. Ten novel genetic variants were reported in this study population. CONCLUSION The phenotypic spectrum of GALE deficiency ranges from asymptomatic to severe. The generalized patients have a phenotype that is in line with the 9 described cases in the literature and prescribing dietary interventions is the cornerstone for treatment. In the non-generalized group, treatment advice is more difficult. To be able to offer proper counseling, in addition to red blood cell enzyme activity, genetic studies, transferrin glycoform analysis and enzymatic measurements in fibroblasts are recommended. Due to lack of facilities, additional enzymatic testing is not common practice in many centers nor a tailored long-term follow-up is performed