bluuebunny/crossref_metadata_2025 huggingface dataset:
REFORMA E RECONTEXTUALIZAÇÃO DAS POLÍTICAS:O PAPEL DOS COORDENADORES PEDAGÓGICOS NAS ESCOLAS MUNICIPAIS DO RIO DE JANEIRO
Authors: Marcondes Maria Inês , Finholdt Angelo Leite Vania , Prado de Oliveira Ana Cristina
Published: May 2018

No Brasil, desde a década de 1990 propostas educacionais têm privilegiado a definição de conteúdos mínimos nacionais, a extensão do tempo de aprendizagem e a aplicação de avaliações externas visando à melhoria da qualidade medida basicamente pelo desempenho dos alunos. No quadro da gestão das escolas de ensino fundamental e médio o coordenador pedagógico tem sido visto como figura central na mediação entre Secretaria de Educação e os professores da escola exercendo funções pedagógicas relacionadas ao desenvolvimento profissional do corpo docente e um trabalho político de implementação dos princípios da reforma. Nesse texto apresentamos dados de uma pesquisa focalizando a atuação de dois coordenadores buscando responder aos seguintes questionamentos: 1) Qual o sentido e o propósito pedagógico e político da atuação do coordenador junto aos professores de duas (2) escolas na busca da qualidade de ensino? 2) Como os coordenadores atuam no trabalho de desenvolvimento profissional dos professores em escolas pautadas por avaliações externas? Quanto ao aspecto metodológico, o estudo baseou-se em observação de reuniões e entrevista com os coordenadores em escolas na cidade do Rio de Janeiro. Como conclusões, nas duas escolas, os coordenadores revelam que há uma recontextualização das políticas havendo uma aceitação parcial delas por parte dos professores. Os professores são críticos em relação a efetiva melhoria da qualidade do ensino. Na escola A as mudanças são atendidas e vistas como políticas temporárias enquanto que na escola B as mudanças são atendidas a medida que não comprometam o projeto pedagógico da escola que envolve leitura e escrita.
Evasão universitária: modelos teóricos internacionais e o panorama das pesquisas no Brasil
Authors: Sisson de Castro Alexandre Kurtz dos Santos , Teixeira Marco Antônio Pereira
Published: May 2018

A evasão no ensino superior é um fenômeno que tem chamado a atenção de gestores e pesquisadores nas últimas décadas. Observa-se na literatura internacional a tentativa de elaboração de diversos modelos teóricos sobre evasão e persistência no ensino superior. Essas pesquisas internacionais, de um modo geral, são elaboradas por pesquisadores que têm como foco o estudo e a avaliação do ensino superior. No Brasil, as pesquisas em evasão são realizadas por pesquisadores dentro de suas próprias áreas. Elas tendem a ser descritivas e exploratórias, focadas no diagnóstico específico de um curso ou instituição. Geralmente, não há um aprofundamento teórico e quando há tende-se a utilizar a teoria de Vincent Tinto como referencial. Contudo, estudos nacionais e internacionais têm sugerido que essa teoria é insuficiente para dar conta do fenômeno. Dado esse quadro, este artigo tem o objetivo de apresentar outros modelos de evasão universitária e discutir os rumos das pesquisas sobre evasão no Brasil. Conclui-se que, para melhorar a qualidade das pesquisas realizadas no Brasil é necessária a elaboração de um modelo de evasão aplicável ao contexto nacional.
A OPINIÃO DE ESTUDANTES DE MEDICINA E ENFERMAGEM SOBRE GRAVIDEZ NA ADOLESCÊNCIA
Authors: Elisa Jager Márcia , Da Costa Souto Danielle , Flores de Lima Raquel , Domingues de Deus Meiridiane , Garcia Dias Ana Cristina
Published: May 2018

Este estudo busca conhecer as opiniões de estudantes de medicina e enfermagem sobre as causas da gravidez durante a adolescência e sobre o atendimento em saúde prestado a essa população. Participaram deste estudo 106 estudantes universitários de ambos os sexos, com idades entre 18 e 27 anos, matriculados nos semestre iniciais dos cursos de Enfermagem e Medicina da Universidade de Passo Fundo. Os principais resultados indicam que os estudantes reconhecem um grau de complexidade envolvido no fenômeno de gravidez adolescente e que seu atendimento necessita ser multidisciplinar, uma vez que envolve tanto aspectos biológicos e sociológicos quanto aspectos culturais e psicológicos. Entretanto, os participantes deste estudo não reconhecem, de fato, a influência do contexto sociocultural sobre a experiência da gestação e maternidade adolescente, apresentando crenças estereotipadas em relação a estas experiências.
ACOMPANHAMENTO TERAPÊUTICO: UM DISPOSITIVO DE DESAFIOS
Authors: Carla Lavarda Concentino Caetano Carla , Cristina Coelho Scisleski Andrea
Published: May 2018

Este texto é parte de um estudo de especialização em Clínica e Saúde. Trazemos questionamentos das Políticas Públicas para infância e juventude, articulando as relações entre saúde e as redes de serviço, bem como práticas da Clínica Ampliada, enfatizando a função do acompanhante terapêutico e evidenciando o Acompanhamento Terapêutico como um dispositivo clínico, capaz de produzir mudanças e atravessamentos na transversalidade do campo da Saúde Coletiva. Para isso, utilizamos uma análise do campo social partindo da história de uma criança que é tomada como problemática por diversas instituições. Também apontamos a função do acompanhante terapêutico como um catalisador entre a criança, as instituições e a cidade, problematizando os modos de relação construídos pelo viés dos saberes e verdades instauradas nesses campos de subjetivação. Com isso, entendemos que as considerações finais ou conclusões não podem ser fechadas e apontamos alguns direcionamentos e mudanças como propulsores de novas práticas em Saúde.
Teacher-researcher: conceptions and practices of master teachers working in primary education
Authors: Buzzi Rausch Rita
Published: May 2018

Although teacher education seeks to form a teacher-research and the research being wellness recognized as a key activity, excellent use and meaning has generated controversy. in this sense, we have investigated: which are the conceptions and practices of research master degree teachers who work in teaching at elementary schools? The objective was to identify the concepts and practices in search of master teachers. This qualitative study that we conducted in semi structured interviews with eight master professors. For the design of the teacher-researcher we have identified three aspects: a) the professional who remains up-to-dated, b) That the professional prioritizes the research over teaching, c) the professional who investigates his/her teaching practice. However, we have not noticed the correct understanding of research as a systematic process, in order to the science related to teaching. Most teachers demonstrated interest in and ability conducting research in the school, however, they have expressed impossibilities due to limiting factors related to the physical structure, lack of time, low salary and poor support from the school managers. They have noticed that the master´s contributed in his/her training as a teacher-researcher. This study allowed us to analyze the educational literature which gives an emphasis on the need to train the teacher-researcher. However, it is not often discussed the history of the teachers´ training, working conditions, career, the financial resources and the infrastructure also necessary for the teacher to be able to conduct research in the schools.
Ten simple rules for writing statistical book reviews
Authors: Lortie Christopher J
Published: May 2018

Statistical books are an opportunity for accessing relatively deeper insights into statistics and software even outside the introductory classroom setting. There are however many resources available to the practitioner in addition to the traditional text model. Book reviews can thus provide a critical mechanism for the learner to assess whether the commitment to a specific book warrants the allocated time and effort. The ten simple rules format, pioneered in computational biology, was applied here to writing effective book reviews for statistics because of the breadth offerings in this domain including topical introductions, computational solutions, and theory. Learning by doing is a popular paradigm in statistics and computation, but there is still a niche for books in the pedagogy of self-taught and instruction-based learning. Primarily, these rules ensure that book reviews function as a form of short syntheses to inform and guide readers in deciding to use a specific book relative to other options for statistical challenges.
Agrichemicals boost the effects of antibiotics on antibiotic resistance evolution
Authors: Kurenbach Brigitta , Hill Amy M , Godsoe William , van Hamelsveld Sophie , Heinemann Jack A
Published: May 2018

Antibiotic resistance is medicine’s climate change: caused by human activity, and resulting in more extreme outcomes. Resistance emerges in microbial populations when antibiotics act on phenotypic variance within the population. This can arise from either genotypic diversity (resulting from a mutation or horizontal gene transfer), or from ‘adaptive’ differences in gene expression due to environmental variation. Adaptive changes can increase fitness allowing bacteria to survive at higher concentrations of the antibiotic. They can also decrease fitness, potentially leading to selection for antibiotic resistance at lower concentrations. There are opportunities for other environmental stressors to promote antibiotic resistance in ways that are hard to predict using conventional assays. Exploiting our observation that commonly used herbicides can increase or decrease the minimum inhibitory concentration (MIC) of different antibiotics, we provide the first comprehensive test of the hypothesis that the rate of antibiotic resistance evolution under specified conditions can increase, regardless of whether a herbicide increases or decreases the antibiotic MIC. Short term evolution experiments were used for various herbicide and antibiotic combinations. We found conditions where acquired resistance arises more frequently regardless of whether the exogenous non-antibiotic agent increased or decreased antibiotic effectiveness. This “damned if you do/damned if you don’t” outcome suggests that the emergence of antibiotic resistance is exacerbated by additional environmental factors that influence competition between bacteria. Our work demonstrates that bacteria may acquire antibiotic resistance in the environment at rates substantially faster than predicted from laboratory conditions.
G9a regulates temporal preimplantation developmental program and lineage segregation in blastocyst
Authors: Zylicz Jan J , Borensztein Maud , Wong Frederick CK , Huang Yun , Lee Caroline , Dietmann Sabine , Surani M Azim
Published: May 2018

Early mouse development is regulated and accompanied by dynamic changes in chromatin modifications, including G9a-mediated histone H3 lysine 9 dimethylation (H3K9me2). Previously, we provided insights into its role in post-implantation development (Zylicz et al., 2015). Here we explore the impact of depleting the maternally inherited G9a in oocytes on development shortly after fertilisation. We show that G9a accumulates typically at 4 to 8 cell stage to promote timely repression of a subset of 4 cell stage-specific genes. Loss of maternal inheritance of G9a disrupts the gene regulatory network resulting in developmental delay and destabilisation of inner cell mass lineages by the late blastocyst stage. Our results indicate a vital role of this maternally inherited epigenetic regulator in creating conducive conditions for developmental progression and on cell fate choices.
Somatic clones heterozygous for recessive disease alleles of BMPR1A exhibit unexpected phenotypes in Drosophila
Authors: Akiyama Takuya , User Sırma D , Gibson Matthew C
Published: May 2018

The majority of mutations studied in animal models are designated as recessive based on the absence of visible phenotypes in germline heterozygotes. Accordingly, genetic studies primarily rely on homozygous loss-of-function to determine gene requirements, and a conceptually-related ‘two-hit model’ remains the central paradigm in cancer genetics. Here we investigate pathogenesis due to somatic mutation in epithelial tissues, a process that predominantly generates heterozygous cell clones. To study somatic mutation in Drosophila, we generated inducible alleles that mimic human Juvenile polyposis-associated BMPR1A mutations. Unexpectedly, four of these mutations had no phenotype in heterozygous carriers but exhibited clear tissue-level effects when present in somatic clones of heterozygous cells. We conclude that these alleles are indeed recessive when present in the germline, but nevertheless deleterious when present in heterozygous clones. This unforeseen effect, deleterious heteromosaicism, suggests a ‘one-hit’ mechanism for disease initiation that may explain some instances of pathogenesis associated with spontaneous mutation.
Structure of a TRPM2 channel in complex with Ca2+ explains unique gating regulation
Authors: Zhang Zhe , Tóth Balázs , Szollosi Andras , Chen Jue , Csanády László
Published: May 2018

Transient receptor potential melastatin 2 (TRPM2) is a Ca2+-permeable cation channel required for immune cell activation, insulin secretion, and body heat control. TRPM2 is activated by cytosolic Ca2+, phosphatidyl-inositol-4,5-bisphosphate and ADP ribose. Here, we present the ~3 Å resolution electron cryo-microscopic structure of TRPM2 from Nematostella vectensis, 63% similar in sequence to human TRPM2, in the Ca2+-bound closed state. Compared to other TRPM channels, TRPM2 exhibits unique structural features that correlate with its function. The pore is larger and more negatively charged, consistent with its high Ca2+ selectivity and larger conductance. The intracellular Ca2+ binding sites are connected to the pore and cytosol, explaining the unusual dependence of TRPM2 activity on intra- and extracellular Ca2+. In addition, the absence of a post-filter motif is likely the cause of the rapid inactivation of human TRPM2. Together, our cryo-EM and electrophysiology studies provide a molecular understanding of the unique gating mechanism of TRPM2.
Neolithic and medieval virus genomes reveal complex evolution of hepatitis B
Authors: Krause-Kyora Ben , Susat Julian , Key Felix M , Kühnert Denise , Bosse Esther , Immel Alexander , Rinne Christoph , Kornell Sabin-Christin , Yepes Diego , Franzenburg Sören , Heyne Henrike O , Meier Thomas , Lösch Sandra , Meller Harald , Friederich Susanne , Nicklisch Nicole , Alt Kurt W , Schreiber Stefan , Tholey Andreas , Herbig Alexander , Nebel Almut , Krause Johannes
Published: May 2018

The hepatitis B virus (HBV) is one of the most widespread human pathogens known today, yet its origin and evolutionary history are still unclear and controversial. Here, we report the analysis of three ancient HBV genomes recovered from human skeletons found at three different archaeological sites in Germany. We reconstructed two Neolithic and one medieval HBV genome by de novo assembly from shotgun DNA sequencing data. Additionally, we observed HBV-specific peptides using paleo-proteomics. Our results demonstrated that HBV has circulated in the European population for at least 7000 years. The Neolithic HBV genomes show a high genomic similarity to each other. In a phylogenetic network, they do not group with any human-associated HBV genome and are most closely related to those infecting African non-human primates. The ancient viruses appear to represent distinct lineages that have no close relatives today and possibly went extinct. Our results reveal the great potential of ancient DNA from human skeletons in order to study the long-time evolution of blood borne viruses.
Downregulation of ribosome biogenesis during early forebrain development
Authors: Chau Kevin F , Shannon Morgan L , Fame Ryann M , Fonseca Erin , Mullan Hillary , Johnson Matthew B , Sendamarai Anoop K , Springel Mark W , Laurent Benoit , Lehtinen Maria K
Published: May 2018

Forebrain precursor cells are dynamic during early brain development, yet the underlying molecular changes remain elusive. We observed major differences in transcriptional signatures of precursor cells from mouse forebrain at embryonic days E8.5 vs. E10.5 (before vs. after neural tube closure). Genes encoding protein biosynthetic machinery were strongly downregulated at E10.5. This was matched by decreases in ribosome biogenesis and protein synthesis, together with age-related changes in proteomic content of the adjacent fluids. Notably, c-MYC expression and mTOR pathway signaling were also decreased at E10.5, providing potential drivers for the effects on ribosome biogenesis and protein synthesis. Interference with c-MYC at E8.5 prematurely decreased ribosome biogenesis, while persistent c-MYC expression in cortical progenitors increased transcription of protein biosynthetic machinery and enhanced ribosome biogenesis, as well as enhanced progenitor proliferation leading to subsequent macrocephaly. These findings indicate large, coordinated changes in molecular machinery of forebrain precursors during early brain development.
A new large-bodied thalattosuchian crocodyliform from the Lower Jurassic (Toarcian) of Hungary, with further evidence of the mosaic acquisition of marine adaptations in Metriorhynchoidea
Authors: Ősi Attila , Young Mark T. , Galácz András , Rabi Márton
Published: May 2018

Based on associated and three-dimensionally preserved cranial and postcranial remains, a new thalattosuchian crocodyliform,Magyarosuchus fitosigen. et sp. nov. from the Lower Jurassic (Upper Toarcian) Kisgerecse Marl Formation, Gerecse Mountains, Hungary is described here. Phylogenetic analyses using three different datasets indicate thatM. fitosiis the sister taxon ofPelagosaurus typusforming together the basal-most sub-clade of Metriorhynchoidea. With an estimated body length of 4.67–4.83 mM. fitosiis the largest known non-metriorhynchid metriorhynchoid. Besides expanding Early Jurassic thalattosuchian diversity, the new specimen is of great importance since, unlike most contemporaneous estuarine, lagoonal or coastal thalattosuchians, it comes from an ‘ammonitico rosso’ type pelagic deposit of the Mediterranean region of the Tethys. A distal caudal vertebra having an unusually elongate and dorsally projected neural spine implies the presence of at least a rudimentary hypocercal tail fin and a slight ventral displacement of the distal caudal vertebral column in this basal metriorhynchoid. The combination of retaining heavy dorsal and ventral armors and having a slight hypocercal tail is unique, further highlighting the mosaic manner of marine adaptations in Metriorhynchoidea.
A Method to Determine Gravity Wave Net Momentum Flux, Propagation Direction, and “Real” Wavelengths: A GPS Radio Occultations Soundings Case Study
Authors: Alexander P. , Schmidt T. , de la Torre A.
Published: May 2018

Atmospheric gravity waves (GW) serve as an essential mechanism in the transport of energy and momentum flux from the low to the upper atmosphere. In the last decades satellite observations have become an important part in the analysis of GW due to their global and frequent coverage. Present procedures often provide GW absolute momentum flux (MF), ambiguous 3‐D propagation direction, and apparent vertical wavelengths. We here introduce a method with close sounding quartets, which allows the calculation for GW of the net MF, the definite propagation direction, and “real” wavelengths. Among the satellite observational techniques, Global Positioning System (GPS) radio occultation (RO) retrievals provide temperature profiles that after adequate processing may yield GW properties like wavelengths, MF, and energy. Our procedure is illustrated by an example under requirements that tend to ensure that four GPS RO soundings are observing the same GW. The future increase of satellite measuring devices due to new missions (including GPS RO) will lead to a higher spatial and temporal density of profiles that may eventually allow the attainment of GW climatologies of net MF, propagation direction, and “real” vertical wavelengths.
Thermo and pH Dual – Actuating Smart Porous Anodic Aluminum for Controllable Drug Release
Authors: Zhao Xiao‐Ping , Wang Shan‐Shan , Younis Muhammad Rizwan , Xia Xing‐Hua , Wang Chen
Published: May 2018

A highly effective dual‐stimuli responsive porous anodic aluminum (PAA) nanomembrane is designed and fabricated for controllable and sustainable drug release. By a two‐step electrochemical anodization process, the nanochannel arrays in PAA membrane are divided into two separated parts. The first part is modified by copolymer‐liposome (colipid), which acts as the thermo and pH dual‐stimuli responsive capping material. The other part is used as the drug loading core. The liposome in capping layer has excellent biocompatibility, and the nanochannels array can provide a high drug loading capacity. Taking dexamethasone as the model drug, the experiment results show that the fabricated nanochannels can be well tuned to open or close state upon pH or temperature stimuli, which allows the controllable and sustainable drug release. The present work is of significant importance for constructing smart and intelligent drug carrier and release systems for clinical applications.
3D CNTs/Graphene‐S‐Al3Ni2 Cathodes for High‐Sulfur‐Loading and Long‐Life Lithium–Sulfur Batteries
Authors: Guo Zeqing , Nie Huagui , Yang Zhi , Hua Wuxing , Ruan Chunping , Chan Dan , Ge Mengzhan , Chen Xi'an , Huang Shaoming
Published: May 2018

Lithium–sulfur batteries suffer from poor cycling stability at high areal sulfur loadings (ASLs) mainly because of the infamous shuttle problem and the increasing diffusion distance for ions to diffuse along the vertical direction of the cathode plane. Here, a carbon nanotube (CNT)/graphene (Gra)‐S‐Al3Ni2 cathode with 3D network structure is designed and prepared. The 3D network configuration and the Al in the Al3Ni2 provide an efficient channel for fast electron and ion transfer in the three dimensions, especially along the vertical direction of the cathode. The introduction of Ni in the Al3Ni2 is able to suppress the shuttle effect via accelerating reaction kinetics of lithium polysulfide species conversion reactions. The CNT/Gra‐S‐Al3Ni2 cathode exhibits ultrahigh cycle‐ability at 1 C over 800 cycles, with a capacity degradation rate of 0.055% per cycle. Additionally, having high ASLs of 3.3 mg cm−2, the electrode delivers a high reversible areal capacity of 2.05 mA h cm−2 (622 mA h g−1) over 200 cycles at a higher current density of 2.76 mA cm−2 with high capacity retention of 85.9%. The outstanding discharge performance indicates that the design offers a promising avenue to develop long‐life cycle and high‐sulfur‐loading Li–S batteries.
Tailored Reaction Route by Micropore Confinement for Li–S Batteries Operating under Lean Electrolyte Conditions
Authors: Wang Hui , Adams Brian D. , Pan Huilin , Zhang Liang , Han Kee Sung , Estevez Luis , Lu Dongping , Jia Haiping , Feng Jun , Guo Jinghua , Zavadil Kevin R. , Shao Yuyan , Zhang Ji‐Guang
Published: May 2018

Lithium‐sulfur (Li–S) batteries are one of the most promising alternative energy storage systems beyond Li‐ion batteries. However, the sluggish kinetics of the nucleation and growth of the solid discharge product of Li2S/Li2S2 in the lower discharge plateau has been recently identified as a critical hurdle for attaining high specific capacity in Li–S batteries with high sulfur loadings under lean electrolyte conditions. Herein, a new strategy of breaking the charge‐transport bottleneck by successful generation of experimentally verified stable Li2S2 and a reservoir of quasi‐solid lithium polysulfides within the micropores of activated carbon fiber cloth as a high‐sulfur‐loading host is proposed. The developed Li–S cell is capable of delivering a highly sustainable areal capacity of 6.0 mAh cm−2 under lower electrolyte to sulfur ratios (<3.0 mLE gS−1). Micropore confinement leads to generation of solid Li2S2 that enables high utilization of the entire electroactive area by its inherent self‐healing capacity. This strategy opens a new avenue for rational material designs for Li–S batteries under lean electrolyte condition.
Click‐to‐Release from trans‐Cyclooctenes: Mechanistic Insights and Expansion of Scope from Established Carbamate to Remarkable Ether Cleavage
Authors: Versteegen Ron M. , ten Hoeve Wolter , Rossin Raffaella , de Geus Mark A. R. , Janssen Henk M. , Robillard Marc S.
Published: May 2018

The bioorthogonal cleavage of allylic carbamates from trans‐cyclooctene (TCO) upon reaction with tetrazine is widely used to release amines. We disclose herein that this reaction can also cleave TCO esters, carbonates, and surprisingly, ethers. Mechanistic studies demonstrated that the elimination is mainly governed by the formation of the rapidly eliminating 1,4‐dihydropyridazine tautomer, and less by the nature of the leaving group. In contrast to the widely used p‐aminobenzyloxy linker, which affords cleavage of aromatic but not of aliphatic ethers, the aromatic, benzylic, and aliphatic TCO ethers were cleaved as efficiently as the carbamate, carbonate, and esters. Bioorthogonal ether release was demonstrated by the rapid uncaging of TCO‐masked tyrosine in serum, followed by oxidation by tyrosinase. Finally, tyrosine uncaging was used to chemically control cell growth in tyrosine‐free medium.
Alternative Strategies with Iodine: Fast Access to Previously Inaccessible Iodine(III) Compounds
Authors: Hokamp Tobias , Mollari Leonardo , Wilkins Lewis C. , Melen Rebecca L. , Wirth Thomas
Published: May 2018

Non‐iodinated arenes can be easily and selectively converted into (diacetoxyiodo)arenes in a single step under mild conditions by using iodine triacetates as reagents. The oxidative step is decoupled from the synthesis of hypervalent iodine(III) reagents, which can now be prepared conveniently in a one‐pot synthesis for subsequent reactions without prior purification. The chemistry of iodine triacetates was also expanded to heteroatom ligand exchanges to form novel inorganic hypervalent iodine compounds.
A novel polycarbonate composite for waveguides
Authors: Wu Xiaolan , Yang Bo , Zhuang Songlin
Published: May 2018

The novel polycarbonate resin compositions comprising polycarbonate (PC) and acrylic resin were prepared by solution blending and analyzed by differential scanning calorimetry, atomic force microscopy, gel permeation chromatography, and gas chromatography‐mass spectrometry. Furthermore, the optical performance and the thermal and mechanical properties were tested, respectively. The results demonstrate that the blended material which was prepared by 100 parts of PC and 0.05 parts of acrylic resin achieves excellent transparency in blue‐light region (280–400 nm). Meanwhile, it retains excellent high‐heat resistance and mechanical performance of PC. Because of its high transparency in the blue‐light region which is caused by a doping of a tiny amount of acrylic resin, this material takes steps towards solving the optical problem that light becomes yellow when leaving the end of waveguides of PC. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46529.
Impact of the starch source on the physicochemical properties and biodegradability of different starch‐based films
Authors: Luchese Cláudia Leites , Benelli Patrícia , Spada Jordana Corralo , Tessaro Isabel Cristina
Published: May 2018

Concern about environmental issues has motivated research into the development of biodegradable packaging from renewable sources. Natural polymers such as starch constitute a good alternative for diminishing the use of nonbiodegradable and nonrenewable components in the packaging industry. However, depending on the botanical source, films with different properties are formed. The aim of this study was to evaluate the film‐forming capacity of different starch sources (cassava, corn, potato, and wheat) by casting with starch contents from 2 to 6%. Principal component analysis methodology was used to evaluate the correlation between the formulations and their physicochemical and mechanical properties. It was not possible to produce continuous films based on potato starch, probably because of its very low amylose content (10%). The corn‐, cassava‐, and wheat‐starch‐based films were characterized by their thicknesses (0.06–0.22 mm), moisture contents (19–26%), water solubilities (13.7–26.5%), water‐vapor permeabilities (WVPs; 0.19–0.48 g mm h−1 m−2 kPa−1), wettabilities (35–106°), biodegradabilities in soil, and thermal and mechanical properties (tensile strength = 1.9–6.7 MPa, elongation = 41–166%, and Young's modulus = 8–127 MPa). The wheat starch films presented higher WVPs and lower mechanical properties. The cassava starch films presented lower wettabilities and good mechanical properties; this suggested that their use in packaging for products, such as fruits and vegetables, with higher water activities could be feasible. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46564.
Cationic starch derivatives as reactive shale inhibitors for water‐based drilling fluids
Authors: Cescon Leonardo dos Santos , Quartarone Priscila , Ribeiro Simone Pereira da Silva , Nascimento Regina Sandra Veiga
Published: May 2018

One of the major problems associated with the use of water‐based drilling fluids is the interaction of water with specific rock formations, such as shales, and the consequent swelling of reactive clays that may be present in that type of rock. Several types of clays reactivity inhibitors have been used by the oil industry, and the most effective ones are the cationic polyelectrolytes, such as the poly(diallyldimethylammonium chloride) (PDADMAC). However, this polyelectrolyte is very toxic. In this work, a series of cationic starch derivatives with different cationic degrees were synthesized with the objective of evaluating their potential as environmentally correct shale reactivity inhibitors. The results showed that the synthesized derivatives presented a good capacity of adsorption on bentonite and an efficient inhibition of the shale reactivity. The derivative with an intermediate cationic degree presented the best performance. In the tests with the formulated fluids this derivative provided an intact cuttings recovery of 84.8% and a total recovery of 92.3%. These values are very close to those found for the PDADMAC additive, therefore indicating that this cationic starch derivative presents a good potential as inhibitor of the shale reactivity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46621.
Trivalent rare‐earth activated hexagonal lanthanum fluoride (LaF3:RE3+, where RE = Tb, Sm, Dy and Tm) nanocrystals: Synthesis and optical properties
Authors: Kasturi Singh , Marikumar R. , Vaidyanathan Sivakumar
Published: May 2018

The LaF3 nanocrystals through a facile hydrothermal route with hexagonal structures have been synthesized via doping of trivalent rare earth (RE3+) ions – RE = Tb, Sm, Dy and Tm – with rod‐like and perforated morphologies using NH4F as fluorine precursor. Hexagonal phase formation was confirmed by powder X‐ray diffraction. The crystalline sizes were calculated by the Scherrer equation where found to have an average crystalline size of 12 to 35 nm. The morphological studies of the nanocrystals were carried out by means of transmission electron microscopy (TEM). The LaF3:Tm3+,Sm3+ ions show the characteristic emission of Tb3+ and Tm3+ respectively. In Sm3+‐doped LaF3, three prominent emission peaks at 561, 597 and 641 nm were found, which belong to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2 (magnetic dipole) and 4G5/2 → 6H9/2 (electric dipole) transitions, respectively. The Dy3+ activated LaF3 shows blue and yellow emission and the corresponding CIE color coordinate show white light emission (CCT value 10650 K).
Effect of viscosity and dielectric constant variation on fractional fluorescence quenching analysis of coumarin dye in binary solvent mixtures
Authors: Bhavya P. , Melavanki Raveendra , Kusanur Raviraj , Sharma Kalpana , Muttannavar V. T. , Naik L. R.
Published: May 2018

Photo physical properties of fluorescent organic compounds give an immense improved knowledge on characteristics of excited state that is beneficial to devise innovate molecules and understand their performance in particular applications. Coumarin derivatives have been extensively investigated in this regard. This article narrates steady state fluorescence quenching measurements of a coumarin derivative namely 3‐hydroxy‐3‐[2‐oxo‐2‐(3‐oxo‐3H‐benzo[f]chromen‐2‐yl)‐ethyl]‐1,3‐dihydro‐indol‐2‐one (3HBCD) in a binary mixture of acetonitrile and 1,4‐dioxane. Aniline is used as quencher. Fluorescence intensity is large in acetonitrile and decreases as the percentage of 1,4‐dioxane in the solvent mixture increases. With modest quencher concentration a deviation towards the x axis is noticed in the Stern–Volmer (S–V) plots. This downward curvature is interpreted as due to the presence of 3HBCD in different conformers in the lowest energy level. Ground state intramolecular hydrogen bonding formation is observed due to the conformational changes in the solute. Figured estimations of various quenching parameters recommend that, while dynamic quenching prompts linearity in S–V plot at lower quencher concentration, increasing quenching efficiency with increasing medium viscosity suggests that reaction is not entirely controlled by material diffusion. Stern–Volmer constant increases with decreasing medium dielectric constant.
Nomograms incorporating genetic variants in BMP/Smad4/Hamp pathway to predict disease outcomes after definitive radiotherapy for non‐small cell lung cancer
Authors: Yang Ju , Xu Ting , Gomez Daniel R. , Yuan Xianglin , Nguyen Quynh‐Nhu , Jeter Melenda , Song Yipeng , Komaki Ritsuko , Hu Ye , Hahn Stephen M. , Liao Zhongxing
Published: May 2018

Hepcidin is crucial in regulating iron metabolism, and increased serum levels were strongly linked with poor outcomes in various malignancies. Thus, we investigated if genetic variants in the BMP/Smad4/Hamp hepcidin‐regulating pathway were associated with outcomes in patients receiving definitive radiotherapy for NSCLC. Subjects were 664 NSCLC patients who received ≥60 Gy radiotherapy for NSCLC retrospectively identified from a single‐institution database. Potentially, functional and tagging single nucleotide polymorphisms (SNPs) of BMP2 (rs170986, rs1979855, rs1980499, rs235768, and rs3178250), BMP4 (rs17563, rs4898820, and rs762642), Smad4 (rs12456284), and Hamp (rs1882694, rs10402233, rs10421768, and rs12971321) were genotyped by TaqMan real‐time polymerase chain reaction. Cox proportional hazard's analyses were used to assess potential influences of SNPs on overall survival (OS), local‐regional progression‐free survival (LRPFS), progression‐free survival (PFS), and distant metastasis‐free survival (DMFS). Nomogram of each endpoint model was developed using R project. The median patient age was 66 years. Most (488 [73.2%]) had stage III NSCLC. Age, disease stage, receipt of concurrent chemotherapy, and gross tumor volume were independent factors of OS. Hamp rs1882694 AC/CC genotypes were associated with poor OS, LRPFS, PFS, and DMFS in multivariate analyses. Besides, BMP2 rs1979855, rs3178250, and rs1980499 associated with PFS; Hamp rs10402233 and BMP2 rs1979855 associated with LRPFS; BMP2 rs3178250 associated with DMFS after adjustment for clinical factors. After adding SNPs to each model, all the likelihood ratios were increased; the nomograms were improved significantly to predict LRPFS (P < 0.001) and PFS (P < 0.001), and marginally to predict OS (P = 0.056) and DM (P = 0.057). Our nomograms incorporating significant SNPs in the BMP/Smad4/Hamp hepcidin‐regulating pathway could improve the prediction of outcomes in patients given definitive radiotherapy for NSCLC. Intensified follow‐ups would be recommended for patients with unfavorable outcomes identified in nomograms. Due to the rapid developments of targeted therapies and immunotherapies for NSCLC, it is necessary to further validate our findings in patients receiving such treatments.
Normal serum protein electrophoresis and mutated IGHV genes detect very slowly evolving chronic lymphocytic leukemia patients
Authors: Chauzeix Jasmine , Laforêt Marie‐Pierre , Deveza Mélanie , Crowther Liam , Marcellaud Elodie , Derouault Paco , Lia Anne‐Sophie , Boyer François , Bargues Nicolas , Olombel Guillaume , Jaccard Arnaud , Feuillard Jean , Gachard Nathalie , Rizzo David
Published: May 2018

More than 35 years after the Binet classification, there is still a need for simple prognostic markers in chronic lymphocytic leukemia (CLL). Here, we studied the treatment‐free survival (TFS) impact of normal serum protein electrophoresis (SPE) at diagnosis. One hundred twelve patients with CLL were analyzed. The main prognostic factors (Binet stage; lymphocytosis; IGHV mutation status; TP53, SF3B1, NOTCH1, and BIRC3 mutations; and cytogenetic abnormalities) were studied. The frequencies of IGHV mutation status, cytogenetic abnormalities, and TP53, SF3B1, NOTCH1, and BIRC3 mutations were not significantly different between normal and abnormal SPE. Normal SPE was associated with Binet stage A, nonprogressive disease for 6 months, lymphocytosis below 30 G/L, and the absence of the IGHV3‐21 gene rearrangement which is associated with poor prognosis. The TFS of patients with normal SPE was significantly longer than that of patients with abnormal SPE (log‐rank test: P = 0.0015, with 51% untreated patients at 5.6 years and a perfect plateau afterward vs. a median TFS at 2.64 years for abnormal SPE with no plateau). Multivariate analysis using two different Cox models and bootstrapping showed that normal SPE was an independent good prognostic marker for either Binet stage, lymphocytosis, or IGHV mutation status. TFS was further increased when both normal SPE and mutated IGHV were present (log‐rank test: P = 0.008, median not reached, plateau at 5.6 years and 66% untreated patients). A comparison with other prognostic markers suggested that normal SPE could reflect slowly advancing CLL disease. Altogether, our results show that a combination of normal SPE and mutated IGHV genes defines a subgroup of patients with CLL who evolve very slowly and who might never need treatment.
Long non‐coding RNA GAS5 is induced by interferons and plays an antitumor role in esophageal squamous cell carcinoma
Authors: Huang Jianbing , Li Yuan , Lu Zhiliang , Che Yun , Sun Shouguo , Mao Shuangshuang , Lei Yuanyuan , Zang Ruochuan , Li Ning , Sun Nan , He Jie
Published: May 2018

The long non‐coding RNA GAS5 has been reported as a tumor suppressor in many cancers. However, its functions and mechanisms remain largely unknown in esophageal squamous cell carcinoma (ESCC). In this study, we found that GAS5 was over‐expressed in ESCC tissue compared with that in normal esophageal tissue in a public database. Functional studies showed that GAS5 could inhibit ESCC cell proliferation, migration and invasion in vitro. Further analysis revealed that GAS5 was regulated by interferon (IFN) responses via the JAK‐STAT pathway. Moreover, as an IFN‐stimulated gene (ISG), GAS5 was a positive regulator of IFN responses. The feedback loop between GAS5 and the IFN signaling pathway plays an important antitumor role in ESCC, thus providing novel potential therapeutic targets.
Sex disparities in acute myocardial infarction care and outcomes
Authors: Gul Burcu , Kozuma Ken , Haimi Ido , Zhao Weiying , Simonton Charles , Ying Shih‐Wa , Buda Alexandra , Mehta Sameer , Baumbach Andreas , Lansky Alexandra
Published: May 2018

Aim

We investigated sex‐based and regional outcomes after contemporary percutaneous coronary intervention (PCI) with the Xience V stent in patients with acute myocardial infarction (AMI).

Methods and Results

This patient level pooled analysis includes three multi‐center, prospective post‐market registries performed in the US, Japan, and China. A total of 1,938 patients treated with Xience V stents in the setting of AMI were enrolled. Compared to men, women had higher major adverse cardiac events (MACE) (14.1% vs. 9.8% P < 0.01, RR 1.4, 95% CI 1.1–1.4) and all‐cause mortality (10% vs. 6.2% P < 0.01, RR 1.61, 95% CI 1.14–2.27) at one year, without any significant difference in device specific outcomes of target vessel failure (TVF). US patients compared to the patients from China and Japan had increased MACE (female: 18% vs. 7.1%, P = 0.0012, male: 15.7% vs. 4.1%, P < 0.0001). Multivariable analysis demonstrated that major bleeding was the strongest predictor of MACE (OR 10.51, 95%CI 4.01–27.50, P < 0.0001), MI (OR 4.26, 95%CI 1.37–13.29, P = 0.012), and all‐cause death (OR 5.3, 95%CI 2.32–12.13, P < 0.0001).

Conclusion

Women with AMI who underwent PCI with XIENCE DES have higher all‐cause mortality at one year in compared to men. Region based outcomes demonstrated increased MACE among US patients compared to the patients from China and Japan. After adjusting for differences in demographics, major bleeding, rather than female sex, predicted the higher observed all‐cause mortality.
Neural network for prediction of 13C NMR chemical shifts of fullerene C60 mono‐adducts
Authors: Kiryanov Ilya I. , Tulyabaev Arthur R. , Mukminov Farit Kh. , Khalilov Leonard M.
Published: May 2018

Real‐valued models based on deep artificial neural networks were proposed to predict 13C NMR chemical shifts of fullerene C60 core carbon atoms for computer‐aided structure elucidation of complex fullerene C60 mono‐adducts. We showed that parametric rectified linear units could be successfully used as activation functions in hidden layers of artificial neural networks for decision of complex physical‐chemical tasks. A total of 400 artificial neural networks were trained and tested in order to reveal the best‐fitted models. The best prediction accuracy of real‐valued models was achieved with MAEP = 1.83 ppm/RMSEP = 2.60 ppm using artificial neural network model which has 110 and 120 hidden units, respectively, with parametric rectified linear unit as activation function.
Optically Active Vibrational Spectroscopy of α‐Aminoisobutyric Acid Foldamers in Organic Solvents and Phospholipid Bilayers
Authors: Lizio Maria Giovanna , Andrushchenko Valery , Pike Sarah J. , Peters Anna D. , Whitehead George F. S. , Vitórica‐Yrezábal Iñigo J. , Mutter Shaun T. , Clayden Jonathan , Bouř Petr , Blanch Ewan W. , Webb Simon J.
Published: May 2018

Helical α‐aminoisobutyric acid (Aib) foldamers show great potential as devices for the communication of conformational information across phospholipid bilayers, but determining their conformation in bilayers remains a challenge. In the present study, Raman, Raman optical activity (ROA), infrared (IR) and vibrational circular dichroism (VCD) spectroscopies have been used to analyze the conformational preferences of Aib foldamers in solution and when interacting with bilayers. A 310‐helix marker band at 1665–1668 cm−1 in Raman spectra was used to show that net helical content increased strongly with oligomer length. ROA and VCD spectra of chiral Aib foldamers provided the chiroptical signature for both left‐ and right‐handed 310‐helices in organic solvents, with VCD establishing that foldamer screw‐sense was preserved when the foldamers became embedded within bilayers. However, the population distribution between different secondary structures was perturbed by the chiral phospholipid. These studies indicate that ROA and VCD spectroscopies are valuable tools for the study of biomimetic structures, such as artificial signal transduction molecules, in phospholipid bilayers.
Chromium (VI) photo‐reduction under visible and sunlight irradiation over bismuth‐ferrites Bi2Fe4O9 photo‐catalyst
Authors: Kebir Mohammed , Boudjemaa Amel , Azoudj Yacine , Sehailia Moussa , Bachari Kaldoun
Published: May 2018

The photo‐catalytic reduction of Cr(VI) in aqueous solution was investigated over spinel ferrites Bi2Fe4O9 photo‐catalyst under both visible and solar light irradiation. The material was prepared by a low‐cost method and characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive x‐ray (EDX), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance spectroscopy (DRS). Electrochemical and photo‐electrochemical studies of the material were also explored. The Bi2Fe3O9 structure had a small band gap (2.05 eV), which allowed the material to absorb more visible light. The photo‐electrochemical characterization in the presence of Na2SO4 indicated that Bi2Fe4O9 is a n‐type semi‐conductor with a flat band of 0.77 V. The influence of the catalyst dose (0.25–1.5 g L−1), the initial concentration of Cr(VI) (25–125 mg L−1), and the irradiation source parameters on the photo‐catalytic performance of Bi2Fe4O9 were studied at pH 2. The results indicated that the reduction rate of Cr(VI) depended on the catalyst's mass and the initial concentration of Cr(VI). By comparing the photo‐reduction activity under visible, ultrasonic, and solar irradiation, it became apparent that the presence of solar light increased the reduction efficiency. The Cr(VI) reduction rate was remarkably different when a combination of sonication and photo‐catalysis was utilized. This work indicated that Bi2Fe4O9 can serve as a promising photo‐catalyst for the photo‐reduction of Cr(VI) under visible light irradiation.
How do anticoagulated atrial fibrillation patients who suffer ischemic stroke or spontaneous intracerebral hemorrhage differ?
Authors: Lehtola Heidi , Hartikainen Juha , Hartikainen Päivi , Kiviniemi Tuomas , Nuotio Ilpo , Palomäki Antti , Ylitalo Antti , Airaksinen K.E. Juhani , Mustonen Pirjo
Published: May 2018

Background

Atrial fibrillation (AF) increases risk of ischemic stroke, and oral anticoagulation (OAC) increases risk of intracerebral hemorrhage (ICH). This study aimed to compare OAC‐treated AF patients with an ischemic stroke/transient ischemic attack (TIA) or spontaneous ICH as their first lifetime cerebrovascular event, especially focusing on patients with therapeutic international normalized ratio (INR).

Hypothesis

We assumed that in AF patients suffering ischemic stroke/TIA or ICH, patient characteristics could be different in patients with therapeutic INR than in patients with warfarin.

Methods

FibStroke is a multicenter, retrospective registry collating details of AF patients with ischemic stroke/TIA or intracranial hemorrhage in 2003–2012. This substudy included AF patients on OAC with first lifetime ischemic stroke/TIA or spontaneous ICH.

Results

A total of 1457 patients with 1290 ischemic strokes/TIAs and 167 ICHs were identified. Of these, 553 (42.9%) strokes/TIAs and 96 (57.5%) ICHs occurred in patients with INR within therapeutic range. During OAC with therapeutic INR, congestive heart failure (odds ratio [OR]: 2.33, 95% confidence interval [CI]: 1.18–4.58) and hypercholesterolemia (OR: 2.52, 95% CI: 1.51–4.19) were more common in patients with ischemic stroke/TIA, whereas a history of bleeding (OR: 0.30, 95% CI: 0.11–0.82) was less common when compared with patients with ICH. In the whole cohort, renal impairment (OR: 1.86, 95% CI: 1.23–2.80) and mechanical valve prosthesis (OR: 4.41, 95% CI: 1.32–14.7) were overrepresented in patients with stroke/TIA, whereas aspirin use (OR: 0.52, 95% CI: 0.30–0.91) and high INR (OR: 0.40, 95% CI: 0.33–0.48) were overrepresented in patients with ICH.

Conclusions

In anticoagulated AF patients with therapeutic INR and first lifetime cerebrovascular event, congestive heart failure and hypercholesterolemia were associated with ischemic stroke/TIA and history of bleeding with ICH.