Pressure effects on the structural and superconducting transitions in La₃Co₄Sn₁₃

La3Co4Sn13 is a superconducting material with transition temperature at Tc = 2.70 K, which presents a superlattice structural transition at T ∗ ≃ 150 K, a common feature for this class of compounds. However, for this material, it is not clear that at T ∗ the lattice distortions arise from a charge density wave (CDW) or from a distinct microscopic origin. Interestingly, it has been suggested in isostructural non-magnetic intermetallic compounds that T ∗ can be suppressed to zero temperature, by combining chemical and external pressure, and a quantum critical point is argued to be observed near these critical doping/pressure. Our study shows that application of pressure on single-crystalline La3Co4Sn13 enhances Tc and decreases T ∗ . We observe thermal hysteresis loops for cooling/heating cycles around T ∗ for P & 0.6 GPa, in electrical resistivity measurements, which are not seen in x-ray diffraction data. The hysteresis in electrical measurements may be due to the pinning of the CDW phase to impurities/defects, while the superlattice structural transition maintains its ambient pressure second-order transition nature under pressure. From our experiments we estimate that T ∗ vanishes at around 5.5 GPa, though no quantum critical behavior is observed up to 2.53 GPa

Antimalarial Exposure Delays Plasmodium falciparum Intra-Erythrocytic Cycle and Drives Drug Transporter Genes Expression

BACKGROUND: Multi-drug resistant Plasmodium falciparum is a major obstacle to malaria control and is emerging as a complex phenomenon. Mechanisms of drug evasion based on the intracellular extrusion of the drug and/or modification of target proteins have been described. However, cellular mechanisms related with metabolic activity have also been seen in eukaryotic systems, e.g. cancer cells. Recent observations suggest that such mechanism may occur in P. falciparum. METHODOLOGY/PRINCIPAL FINDINGS: We therefore investigated the effect of mefloquine exposure on the cell cycle of three P. falciparum clones (3D7, FCB, W2) with different drug susceptibilities, while investigating in parallel the expression of four genes coding for confirmed and putative drug transporters (pfcrt, pfmdr1, pfmrp1 and pfmrp2). Mefloquine induced a previously not described dose and clone dependent delay in the intra-erythrocytic cycle of the parasite. Drug impact on cell cycle progression and gene expression was then merged using a non-linear regression model to determine specific drug driven expression. This revealed a mild, but significant, mefloquine driven gene induction up to 1.5 fold. CONCLUSIONS/SIGNIFICANCE: Both cell cycle delay and induced gene expression represent potentially important mechanisms for parasites to escape the effect of the antimalarial drug

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The percentages of dispersal modes per plot are included as Supporting Information (Table S7, based on 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests in Amazonia). The dispersal modes assigned to these 5433 species and morphospecies are also included as Supporting Information (Table S8).Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.Colombian institution Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIASFaculty of Sciences, Universidad de los Ande

Prevalência de TDAH em quatro escolas públicas brasileiras ADHD prevalence in four brazilian plublic schools

OBJETIVO: Determinar a prevalência de transtorno de déficit de atenção/hiperatividade (TDAH) em crianças de quatro escolas públicas brasileiras. MÉTODO: Estudo de prevalência. A população consistiu em todos os alunos de 1ª à 4ª séries do ensino fundamental com idades entre 6 e 12 anos de quatro escolas públicas (CIEPs). Na primeira etapa do estudo, os professores efetuaram triagem para TDAH utilizando os critérios diagnósticos do Manual Diagnóstico e Estatístico de Transtornos Mentais - IV Edição (DSM-IV). A triagem resultou em dois grupos de crianças: suspeitos e não suspeitos. Na segunda etapa, os pais das crianças suspeitas foram convidados a comparecerem à escola para entrevista com os pesquisadores e preenchimento dos critérios diagnósticos de TDAH, anamnese e exame físico pediátrico e neurológico. Ao final desta etapa, as crianças foram classificadas em "casos" de TDAH e crianças "indeterminadas" (crianças que preenchiam parcialmente os critérios diagnósticos). RESULTADOS: De uma população de 602 alunos, 461 fizeram parte do estudo. A prevalência de TDAH considerando o conjunto das 4 escolas foi 13%. A proporção masculino: feminino foi 2:1. O subtipo de TDAH mais freqüente foi o misto com 61,7% dos casos. CONCLUSÃO: A prevalência de TDAH nestes escolares brasileiros (13%) é mais elevada que a prevalência tradicionalmente mencionada (3-5%). O sexo masculino foi mais acometido que o feminino e o subtipo de TDAH mais prevalente foi o misto, ambos de acordo com estudos anteriores.<br>OBJECTIVE: To define the prevalence of attention-deficit/hyperactivity disorder (ADHD) in children from four Brazilian public elementary schools. METHOD: Study population consisted of all students from the first through fourth grades, age range 6-12 years, who attended four public elementary schools (CIEPs). This prevalence study comprised two steps. During the first step, school teachers screened their own pupils for ADHD using diagnostic criteria from the Diagnostic and Statistic Manual of Mental Disorders - Fourth Edition (DSM-IV). Screening resulted in two groups of children: suspects and non-suspects. In the second step, parents of suspect children were invited for an interview with the researchers, during which they filled ADHD symptoms questionnaire, and in addition a complete history, pediatric physical exam, and neurological exam were performed. At the end of this step, students were classified as "cases" or "undetermined", i.e., those who partially met ADHD diagnostic criteria. RESULTS: From a population of 602 students, 461 were recruited. Considering all four elementary schools, ADHD prevalence was 13%. Male to female ratio was 2:1. The most frequent ADHD subtype was the combined one, accounting for 61.7% of all cases. CONCLUSION: ADHD prevalence in a sample of school-aged children (13%) was higher than the rate that traditionally has been mentioned (3-5%). Boys were more frequently affected than girls and the most prevalent ADHD subtype was the combined subtype, and the latter two findings are concordant with previous studies

Nurses' understanding of standard precautions at a public hospital in Goiania - GO, Brazil Comprensión sobre precauciones modelo por los enfermeros de un hospital público de Goiania - GO, Brasil Compreensão sobre precauções padrão pelos enfermeiros de um hospital público de Goiânia - GO

Standard Precautions (SP) are effective strategies to prevent and control nosocomial infections. This study aimed to verify nurses' understanding about standard precaution measures. Data were collected through interviews, followed by content analysis in accordance with Bardin. Eighty-two nurses took part in this study, 75.6% of whom understand SP as protective measures: for professionals (11.0%); for both professionals and patients (52.4%); for patient care independently of the diagnosis (7.3%); for patients with diagnosed infection (9.8%). Other nurses indicated SP as human care (4.9%) and only as Individual Protection Equipment (IPE) (11.0%). Most participants' understanding points to favorable cognitive adaptation to the daily implementation of SP. However, reductionist and even mistaken perceptions about their range persist, which makes the social function of these measures vulnerable.<br>Las precauciones modelo constituyen estrategias efectivas para la preservación y el control de las infecciones en los servicios de atención a la salud. La finalidad de esta investigación fue constatar la comprensión de los enfermeros respecto a las medidas de precaución modelo. Los datos fueron obtenidos a través de entrevista, seguida de un análisis de contenido de acuerdo con Bardin. Participaron de este estudio 82 enfermeros y el 75,6% de estos comprende las precauciones modelo como medidas de protección: para el profesional (11,0%), para el profesional y para el paciente (52,4%); en la atención al paciente independiente del diagnóstico (7,3%); en la atención a pacientes que se sabe que están infectados (9,8%). Otros enfermos se refirieron a las precauciones modelo como cuidado humano (4,9%) y apenas como la utilización de un equipo de protección individual (EPI) (11,0%). La comprensión emitida por la mayoría de los sujetos presenta adecuación de conocimiento favorable a la implementación de las precauciones modelo diariamente. Mientras tanto, fueron comprobadas percepciones de reducción y hasta distorsionadas del alcance de estas, lo que deja vulnerable la función social de estas medidas.<br>As precauções padrão (PP) constituem estratégias efetivas para a prevenção e controle das infecções, em Serviços de Assistência à Saúde. O objetivo desta investigação foi verificar a compreensão dos enfermeiros sobre as medidas de PP. Os dados foram obtidos por meio de entrevistas com posterior Análise de Conteúdo conforme Bardin. Participaram do estudo 82 enfermeiros e 75,6% compreenderam as PP como medidas de proteção: para o profissional (11,0%); para o profissional e o paciente (52,4%); no atendimento ao paciente independente do diagnóstico (7,3%); e a pacientes sabidamente infectados (9,8%). Outros enfermeiros relataram as PP como cuidado humano (4,9%) e apenas como o uso de EPI (11,0%). A compreensão emitida pela maioria dos sujeitos aponta adequação cognitiva favorável à implementação das PP no cotidiano. Entretanto, foram verificadas percepções reducionistas e até distorcidas da sua abrangência, o que coloca vulnerável a função social de tais medidas