Weyl spin-momentum locking in a chiral topological semimetal.

Spin-orbit coupling in noncentrosymmetric crystals leads to spin-momentum locking - a directional relationship between an electron's spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin-momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin-momentum locking has remained elusive in experiments. Theory predicts that Weyl spin-momentum locking can only be realized in structurally chiral cubic crystals in the vicinity of Kramers-Weyl or multifold fermions. Here, we use spin- and angle-resolved photoemission spectroscopy to evidence Weyl spin-momentum locking of multifold fermions in the chiral topological semimetal PtGa. We find that the electron spin of the Fermi arc surface states is orthogonal to their Fermi surface contour for momenta close to the projection of the bulk multifold fermion at the Γ point, which is consistent with Weyl spin-momentum locking of the latter. The direct measurement of the bulk spin texture of the multifold fermion at the R point also displays Weyl spin-momentum locking. The discovery of Weyl spin-momentum locking may lead to energy-efficient memory devices and Josephson diodes based on chiral topological semimetals.

Charge Transfer and Orbital Reconstruction at an Organic-Oxide Interface.

The two-dimensional electron system (2DES) located at the surface of strontium titanate (STO) and at several other STO-based interfaces has been an established platform for the study of novel physical phenomena since its discovery. Here we report how the interfacing of STO and tetracyanoquinodimethane (TCNQ) results in a charge transfer that depletes the number of free carriers at the STO surface, with a strong impact on its electronic structure. Our study paves the way for efficient tuning of the electronic properties, which promises novel applications in the framework of oxide/organic-based electronics.

Universal Structural Influence on the 2D Electron Gas at SrTiO3 Surfaces.

The 2-dimensional electron gas (2DEG) found at the surface of SrTiO3 and related interfaces has attracted significant attention as a promising basis for oxide electronics. In order to utilize its full potential, the response of this 2DEG to structural changes and surface modification must be understood in detail. Here, a study of the detailed electronic structure evolution of the 2DEG as a function of sample temperature and surface step density is presented. By comparing the experimental results with ab initio calculations, it is shown that local structure relaxations cause a metal-insulator transition of the system around 135 K. This study presents a new and simple way of tuning the 2DEG via surface vicinality and identifies how the operation of prospective devices will respond to changes in temperature.

Proximity-Induced Novel Ferromagnetism Accompanied with Resolute Metallicity in NdNiO3 Heterostructure.

Employing X-ray magnetic circular dichroism (XMCD), angle-resolved photoemission spectroscopy (ARPES), and momentum-resolved density fluctuation (MRDF) theory, the magnetic and electronic properties of ultrathin NdNiO3 (NNO) film in proximity to ferromagnetic (FM) La0.67 Sr0.33 MnO3 (LSMO) layer are investigated. The experimental data shows the direct magnetic coupling between the nickelate film and the manganite layer which causes an unusual ferromagnetic (FM) phase in NNO. Moreover, it is shown the metal-insulator transition in the NNO layer, identified by an abrupt suppression of ARPES spectral weight near the Fermi level (EF ), is absent. This observation suggests that the insulating AFM ground state is quenched in proximity to the FM layer. Combining the experimental data (XMCD and AREPS) with the momentum-resolved density fluctuation calculation (MRDF) reveals a direct link between the MIT and the magnetic orders in NNO systems. This work demonstrates that the proximity layer order can be broadly used to modify physical properties and enrich the phase diagram of RENiO3 (RE = rare-earth element).

AVALIAÇÃO DO CONHECIMENTO DE ESTUDANTES DE ODONTOLOGIA SOBRE MARKETING DIGITAL / ASSESSMENT OF DENTISTRY STUDENTS KNOWLEDGE ABOUT DIGITAL MARKETING

Os meios de comunicação digitais tornaram-se uma ferramenta amplamente utilizada para fins pessoais e profissionais por grande parte da população. Diante dessa realidade contemporânea, o marketing digital vem trazendo facilidades e vantagens para o cotidiano, sendo considerado uma excelente proposta de divulgaçãopor parte dos cirurgiões-dentistas em busca de melhores resultados na odontologia.Com base nessa perspectiva, o presente estudo avaliou o conhecimento de estudantes de odontologia sobre a importância do marketing digital para o sucesso e bom desenvolvimento na prática odontológica. A coleta de dados foi realizada no Centro Universitário Serra dos Órgãos ­ UNIFESO, localizado no município de Teresópolis-RJ. Participaram do estudo, 151 estudantes devidamente matriculados no 1º ao 5º ano do curso de graduação em odontologia, que responderam um questionário, pré testado, contendo 10 perguntas do tipo objetivas diretas. Com base nos resultados, observou-se respostas consideravelmente proporcionais quando comparadas por diferentes anos da graduação, não demonstrando crescente avanço no conteúdo com o decorrer do curso de graduação, portanto, cabe ressaltar que o assunto precisa ser melhor abordado, devendo ser considerada e analisada essa possibilidade pelas diversas instituições por todo o país.

The digital media became a widely used tool for personal and professional purposes by much of the population. Before this contemporary reality, digital marketing has brought daily facilities and advantages, being considered an excellent proposal of disclosure by dentists in search of better results in dentistry. Based on this perspective, this study evaluated dentistry students knowledge of the importance of digital marketing for success and good development in dental practice. The data collection was performed at the Serra dos Orgãos University Center - UNIFESO, located in the municipality of Teresópolis-RJ. The study included 151 students properly enrolled in the 1st to 5th year of the undergraduate course in dentistry, who answered a pre-testedquestionnairecontaining 10 direct objective questions. Based on the results, it was observed considerably proportional responses when compared for different years of graduation, not demonstrating increasing progress in content over the course of the undergraduate, therefore, it may to stand out that the topic needs to be better approached, this possibility should be considered and analyzed by the various institutions throughout the country.

Triple-Point Fermions in Ferroelectric GeTe.

Ferroelectric α-GeTe is unveiled to exhibit an intriguing multiple nontrivial topology of the electronic band structure due to the existence of triple-point and type-II Weyl fermions, which goes well beyond the giant Rashba spin splitting controlled by external fields as previously reported. Using spin- and angle-resolved photoemission spectroscopy combined with ab initio density functional theory, the unique spin texture around the triple point caused by the crossing of one spin-degenerate and two spin-split bands along the ferroelectric crystal axis is derived. This consistently reveals spin winding numbers that are coupled with time-reversal symmetry and Lorentz invariance, which are found to be equal for both triple-point pairs in the Brillouin zone. The rich manifold of effects opens up promising perspectives for studying nontrivial phenomena and multicomponent fermions in condensed matter systems.

Validation of a scale to evaluate the abusive use of technologies (Computer, cell phone, tablet, among others)

BACKGROUND INFORMATION: Daily, prolonged interactivity of individuals with technologies (computer, cell phone, tablet, among others) impacts life and significantly changes habits, behaviors, personal and social relationships. Technologies lead to a multitude of advantages, but attention is required concerning possible damages. OBJECTIVE: Validation of a scale to evaluate the abuse use of technologies (TAUS). METHOD: TAUS validation was carried out in 5 phases: (1) initial scale construction with 20 questions, (2) expert evaluation, (3) application to 200 volunteers, (4) statistical analysis and results, (5) preparation of the final version of the validated TAUS. We used the R statistical program and the "dplyr" package version 3.4.2 to present descriptive statistics, to test hypotheses of means differences and for factorial analysis. Factor analysis was used for the orthogonal model. The method used was Principal Components based on Spearman's correlation matrix. RESULTS: The results provided a final, validated version of a TAUS suitable for clinical and research contexts. The last step of the study was to calculate Cronbach's alpha, in order to measure the internal consistency of the scale. The value found was 0.910, which is considered good. CONCLUSIONS: This Technology Abuse Scale may contribute to future studies, to the conscious use of technologies, to a reduction of physical and emotional damage and to an improvement of the subjects' quality of life.

Validation of a scale to evaluate Digital Dependence of Employees

BACKGROUND: The evolution of technologies and mobility, new digital resources have emerged transforming human behavior. These include the abusive use of digital devices, leading to various dependences regarding the way people use technology. Collective environments also begin to exhibit symptoms of such dependences. OBJECTIVE: Validate a Digital Dependence of Employees Scale (DDES), applied to personnel not holding leadership positions in organizations. METHOD: Data were collected via Internet. The sample totaled 301 volunteers from a state-owned company, of which 294 were statistically validated. Participants were asked to answer 20 questions prepared by experts. After the collection procedure, a database was created for statistical analysis. RESULTS: Statistical analysis procedure including factorial analysis was conducted, which confirmed data adequacy. Three statistical criteria were used: Bartlett Sphericity test, Kaiser-Meyer-Olkin Criterion and Factorial analysis, including Screeplot; the latter determined adequate commonalities, indicating the cancellation of only 1 out of the 20 original scale questions. The internal consistency of the scale measured through the Cronbach Alpha Coefficient showed a positive result of 0.764. Thus, scale validation objectives were achieved. CONCLUSION: The DDES scale was considered validated to be applied to employees in organizational environments. The limitations found to apply the scale did not compromise its results.

Validation of a scale to assess Facebook dependence

BACKGROUND INFORMATION: Facebook is a social network that has become part of the everyday life of contemporary humanity and is notably the most accessed digital tool, worldwide; through it, one can simultaneously relate to millions of people, as a source of information, communication or entertainment. OBJECTIVE: To produce and validate a scale to evaluate Facebook dependence (FDS). METHOD: Validation was performed in 5 phases: 1- initial scale construction with 20 questions, 2- expert evaluation, 3- application in 200 volunteers, 4- statistical analysis and results, and 5- elaboration of the final 18-question validated version of FDS. RESULTS: We obtained a descriptive statistical analysis, a clear-cut separation of dependents vs. non-dependents and a successful factorial analysis. These results provided a validated version of FDS. CONCLUSIONS: We were able to construct the validated final version of FDS with 18 questions appropriate to the clinical contexts and to be used in conducting research on Facebook dependence. This scale will contribute to future research related to this specific digital dependence, hopefully reducing harmful effects and improving quality of life.

Validation of the scale to evaluate physical damages related to the Abusive Use of Technology in daily life (PDAUTS)

BACKGROUND INFORMATION: New computer technologies, namely smart cellphones and tablets, among others, interacting along the daily life of individuals may contribute toward the rise of problems: depression, stress and physical damage (undue postures, upper and lower extremity disorders, vision problems, obesity), all of them related to excessive time spent on technological equipment; together with inadequate furniture, quality of life can be seriously affected. OBJECTIVE: To validate a scale to evaluate physical damage related to the Abusive Use of Technology (PDAUTS) in daily life. METHODS: Validation of the PDAUTS was performed through 5 phases: (1) initial scale construction with 20 questions; (2) expert evaluation of questions; (3) application to 200 volunteers; (4) statistical analysis of the results; (5) preparation of the final validated version, retaining the 20 questions. RESULTS: We used the R statistical program, version 3.4.2 and the "dplyr" package to present the descriptive statistics, the hypothesis tests of mean differences and the factor analysis. The results provided a validated final version for PDAUTS. The last step of the study was to calculate Cronbach's alpha parameter, in order to measure the internal consistency of the scale. The value found was 0.897, which in is considered very good. CONCLUSION: The validated PDAUTS allowed us to evaluate physical damage in each subject and design adequate training and treatment programs, reducing overall impairments and contributing to the improvement in quality of life.

Validation of the Cell Phone Dependence Scale

BACKGROUND INFORMATION: The boundary between cellphone use and abuse is quite tenuous. Research is required to evaluate the use of this device interacting in the everyday life of users, whether to speak or to perform tasks. OBJECTIVE: To construct a novel and specific scale to evaluate cellphone dependence checking its psychometric properties for clarity, accuracy and reliability. METHODS: Validation of a Cellphone Dependence Scale (CPDS) was performed in 5 phases: 1- initial scale construction with 20 questions, 2- expert evaluation, 3- application to 200 volunteers, 4- statistical analysis and results, and 5- elaboration of the final version of the CPDS. RESULTS: We used the R statistical program Version 3.4.2 and the "dplyr" package to present the descriptive statistics, the hypotheses tests of differences of means and the factorial analysis. The results provided a validated and accepted final version for CPDS. The last step of the study was to calculate Cronbach's alpha, in order to measure the internal consistency of the questionnaire. The value found was 0.897, which is considered very good. CONCLUSIONS: This project resulted in the construction of the final CPDS version suitable for the clinical context and to be used in the conduct of research on cellphone dependence. CPDS may contribute to future studies, conscious use of cellphones, harm reduction, and improved quality of life vis-à-vis the cellphone.

Validation of the scale for assessing depression and its relation to technology dependence

ABSTRACT BACKGROUND: The daily coexistence with the technologies (computer, mobile phone, tablet, among others), begins to produce significant changes in human behavior. We have observed that there is an association between dependence on technologies and major depressive disorder, as well as with other mental disorders. OBJECTIVE: To validate a scale for assessing depression and its relation to dependence on everyday technologies. METHODS: Validation of a Technology Dependent Depression Scale (TDDS) was performed in 5 phases: (1) initial scale construction with 20 questions; (2) expert evaluation; (3) application to 100 volunteers, (4) statistical analysis and results, (5) preparation of the final version of the validated TDDS. RESULTS: We used the R statistical program, version 3.4.2 and the "dplyr" package to present descriptive statistics, hypotheses tests of mean differences and factorial analysis. The results provided a validated and approved final version for TDDS. CONCLUSIONS: We constructed the final version of the validated TDDS, which is adequate for clinical contexts and to be used in future research. All the psychometric properties were checked for accuracy, reliability, presentation, clarity, pertinence and comprehension of the instrument conferring validity to the end-product.

Scale to Assess Leaders' Perceptions about their Workers' Digital Addiction.

BACKGROUND: With the evolution of technologies and the mobility factor, new digital devices have emerged, influencing human behavior and provoking diverse dependencies due to their abusive use. Collective environments begin to exhibit the symptoms of such dependencies, compromising people's quality of life (QOL). The objective of the present study was to validate the scale to evaluate the perception of leaders on digital employee addiction (EPLDDE) initially with 17 questions. METHODS: The scale was constructed with real situations of digital addiction and through the evaluation of the semantic comprehension and consistency of the items by judges until final formatting of the instrument. Data collection was done via the internet. The sample consisted of 312 volunteers from a federal state-owned company. After data collection, a database was created for statistical analysis. Statistical program R was used. FINDINGS: Bartlett's and Kaiser-Meyer-Olkin (KMO) tests confirmed adequacy for factorial analysis. Three statistical criteria were used, and scree plot presented adequate commonalities indicating 5 factors and the withdrawal of 3 questions from the scale. In the second AF, results ratified 14 questions. Cronbach's alpha showed a positive result of 0.8131717. CONCLUSION: The 14-item EPLDDE scale was validated for the evaluation of the perception of leaders regarding digital dependence of employees in organizations. This scale can contribute to studies on organizational QOL. The limitations found did not compromise the results.

Cateterismo de artéria mesentérica para tratamento de trombose de veia porta / Catheterization of the mesenteric artery to treat portal vein thrombosis

A trombose de veia porta é uma causa rara de abdome agudo vascular e está diretamente relacionada a trombofilias hereditárias ou adquiridas. O caso de um paciente de 60 anos, sexo masculino, com quadro clínico de isquemia mesentérica confirmada por exame de imagem é apresentado. Foi submetido a enterectomia e enteroanastomose e, após esplenoportografia que detectou trombose de veia porta, indicou-se tratamento medicamentoso com infusão contínua de ativador tecidual do plasminogênio recombinante (Alteplase) através de cateterismo seletivo da artéria mesentérica superior. Trata-se de um tratamento inovador. Obteve-se sucesso na recanalização do sistema porta. O paciente evoluiu com quadro de sepse abdominal, necessitando de assistência em terapia intensiva por 25 dias. Evoluiu bem e recebeu alta hospitalar com o uso de anticoagulante. O artigo apresenta uma breve revisão de literatura e discussão do caso clínico

Portal vein thrombosis is a rare vascular cause of acute abdomen and it is directly related to hereditary or acquired thrombophilias. This article presents the case of a 60-year-old male patient, with clinical signs of mesenteric ischemia that was confirmed by imaging examination. He underwent enterectomy and enteroanastomosis and, after detection of portal vein thrombosis by splenoportography, he was prescribed drug-based treatment with continuous infusion of recombinant tissue plasminogen activator (Alteplase) via selective catheterization of the superior mesenteric artery. This is a treatment innovation. The portal system was successfully recanalized. However, the patient developed abdominal sepsis and required intensive care for 25 days. His clinical status improved and he was discharged with a prescription for oral anticoagulant. This article presents a brief review of the literature and a discussion of portal vein thrombosis

Internet Addiction and Excessive Social Networks Use: What About Facebook?

Facebook is notably the most widely known and used social network worldwide. It has been described as a valuable tool for leisure and communication between people all over the world. However, healthy and conscience Facebook use is contrasted by excessive use and lack of control, creating an addiction with severely impacts the everyday life of many users, mainly youths. If Facebook use seems to be related to the need to belong, affiliate with others and for self-presentation, the beginning of excessive Facebook use and addiction could be associated to reward and gratification mechanisms as well as some personality traits. Studies from several countries indicate different Facebook addiction prevalence rates, mainly due to the use of a wide-range of evaluation instruments and to the lack of a clear and valid definition of this construct. Further investigations are needed to establish if excessive Facebook use can be considered as a specific online addiction disorder or an Internet addiction subtype.

Chemical Analysis of Pottery Demonstrates Prehistoric Origin for High-Altitude Alpine Dairying.

The European high Alps are internationally renowned for their dairy produce, which are of huge cultural and economic significance to the region. Although the recent history of alpine dairying has been well studied, virtually nothing is known regarding the origins of this practice. This is due to poor preservation of high altitude archaeological sites and the ephemeral nature of transhumance economic practices. Archaeologists have suggested that stone structures that appear around 3,000 years ago are associated with more intense seasonal occupation of the high Alps and perhaps the establishment of new economic strategies. Here, we report on organic residue analysis of small fragments of pottery sherds that are occasionally preserved both at these sites and earlier prehistoric rock-shelters. Based mainly on isotopic criteria, dairy lipids could only be identified on ceramics from the stone structures, which date to the Iron Age (ca. 3,000-2,500 BP), providing the earliest evidence of this practice in the high Alps. Dairy production in such a marginal environment implies a high degree of risk even by today's standards. We postulate that this practice was driven by population increase and climate deterioration that put pressure on lowland agropastoral systems and the establishment of more extensive trade networks, leading to greater demand for highly nutritious and transportable dairy products.

Social networking, a new online addiction: a review of Facebook and other addiction disorders / Rede social ou novo vício on-line: uma revisão sobre o transtorno de dependência de Facebook

INTRODUCTION: Facebook is the world's most widely accessed social network, where millions of people intercommunicate. Behavioral and psychological changes relate to abusive and uncontrolled use creating severe impacts on users' life. METHOD: A critical revision was performed through MedLine, Lilacs, SciELO and Cochrane databases using the terms: "Facebook Addiction," "Social Network Sites," "Facebook Abuse." The search covered the past 5 years up to January 2015. Articles that examine dependence on Facebook in the general population were included; we analyzed how this concept evolved over the last five years, and hope to contribute to the better understanding of the issue and its impacts. RESULTS: Although controversial, published reports correlate Facebook addiction to mechanisms of reward and gratification. Some users developed an abusive relationship stimulated by the false feeling of satisfaction or as a way to feel better or more self-assured (increased level of excitement or escape). Studies from several countries indicate different prevalence, probably due to lack of consensus, and the use of different denominations, giving rise to the adoption of different diagnostic criteria. CONCLUSION: Social Networks are modern communication tools; however, not only benefits, but also subsequent damage caused by its abusive use must be monitored. Many users with abusive usage and dependence recognize significant losses in their personal, professional, academic, social and family lives. Further investigation is needed to determine if abusive Facebook usage is a new psychiatric classification or merely the substrate of other disorders.

INTRODUÇÃO: O Facebook é a rede social mais amplamente acessada do mundo, onde milhões de pessoas se comunicam entre si. As alterações comportamentais e psicológicos relacionadas com seu uso abusivo e excessivo estão criando sérios impactos sobre a vida dos usuários. MÉTODO: Uma revisão sistemática foi feita através das bases de dados Medline, Lilacs, SciELO e Cochrane usando os termos: "Facebook Addiction," "Social Network Sites," "Facebook Abuse.". A pesquisa abrangeu os últimos 5 anos até janeiro de 2015. Os artigos que examinam a dependência do Facebook na população em geral foram incluídos; analisamos como esse conceito evoluiu ao longo dos últimos cinco anos, e espera-se contribuir para o melhor entendimento da questão e seus impactos. RESULTADOS: Apesar de controversos, relatórios publicados correlacionam a dependência de Facebook a mecanismos de recompensa e gratificação. Alguns usuários desenvolveram um relacionamento abusivo estimulados pela falsa sensação de satisfação ou como uma maneira de se sentir melhor ou mais auto-confiante (aumento do nível de excitação ou fuga). Estudos de vários países indicam prevalência diferente, provavelmente devido à falta de consenso e ao uso de diferentes denominações, dando origem à adopção de critérios de diagnóstico diferentes. CONCLUSÃO: As redes sociais são ferramentas de comunicação modernas; existem inúmeros benefícios, mas também deve ser monitorado os danos subseqüentes causados por seu uso abusivo. Muitos usuários com o uso abusivo ou dependente declaram perdas significativas em suas vidas pessoais, profissionais, acadêmicos, sociais e familiares. É necessária uma investigação mais profunda para determinar se o uso abusivo do Facebook é uma nova classificação psiquiátrica ou meramente o substrato de outros transtornos.

Effect of GaAIAs laser on reactional dentinogenesis induction in human teeth.

OBJECTIVE: This study investigated the biomodulatory effect of the gallium- aluminum-arsenate laser (GaAlAs) in pulp cells on reactional dentinogenesis, and on the expression of collagen type III (Col III), tenascin (TN), and fibronectin (FN) in irradiated dental tissues and controls (not irradiated). BACKGROUND DATA: Several studies suggest a biomodulatory influence of low-intensity laser radiation in the inflammatory and reparative processes of biological tissues. METHODS: Sixteen human premolar teeth were selected (after extraction due to orthodontal reasons) and divided into irradiated and control groups. Black class V cavity preparations were accomplished in both groups. For the irradiated group, GaAlAs laser (670 nm, 50 mW) with an energy density of 4 J/cm2 was used. Soon after, the cavities were restored with a glass ionomer and the extractions made after 14 and 42 days. RESULTS: Histological changes were observed by light microscopy; less intense inflammatory reaction in the irradiated group was found when compared to the controls. Only the irradiated group of 42 days exhibited an area associated with reactional dentinogenesis. After immunohistochemical analysis by the streptoavidin-biotin complex (SABC) method, the expression of Col III, TN, and FN was greater in the irradiated groups. CONCLUSION: Our results suggest that a GaAlAs laser with energy density of 4 J/cm2 and wavelength of 670 nm caused biomodulation in pulp cells and expression of collagen, but not collagen of the extracellular matrix, after preparation of a cavity.