bluuebunny/crossref_metadata_2025 huggingface dataset:
Adherenceto treatment and life style of patients with hypertension / Adesão ao tratamento e hábitos de vida de hipertensos
Authors: Turra Luana , Restelatto Márcia Terezinha da Rocha , Dallacosta Fabiana Meneghetti
Published: January 2019

Objetivo: analisar a adesão ao tratamento anti-hipertensivo e hábitos de vida de hipertensos. Métodos: Estudo transversal, realizado com hipertensos da Estratégia Saúde da Família de Lacerdópolis, SC. Utilizou-se entrevista e o Brief Medication Questionnaire. Resultados: participaram 72 hipertensos, 68,1% mulheres, idade média 68,4 anos (±12,1). Quanto à adesão ao tratamento, 6,9% são aderentes, 19,4% tem provável adesão, 70,8% provável baixa adesão e 2,8% baixa adesão. Quem usa múltiplas doses é menos aderente (p=0,00), falharam mais em listar o que usam (p=0,03) e omitiram mais (p=0,02). Houve dificuldades para ler o rótulo, abrir a medicação e lembrar de tomar todos os dias, e 19,4% relataram falha de dias ou doses. Conclusão: houve dificuldade em listar a medicação em uso, ler, abrir e lembrar-se de tomar a medicação, especialmente naqueles acima de 60 anos. A prescrição de múltiplas doses interfere significativamente na adesão ao tratamento e no correto uso da medicação.
Profile of patients submitted to hemodialytic treatment in a Theresin clinic / Perfil dos pacientes submetidos a tratamento hemodialítico em uma clínica em Teresina
Authors: Santana Érica Costa
Published: January 2019

Objetivos: Caracterizar a amostra do estudo de acordo com os dados socioeconômicos; identificar doença de base e tempo de hemodiálise; identificar o tipo de acesso no tratamento hemodialítico. Método: Pesquisa exploratória, descritiva, quantitativa, realizada em uma clínica especializada em hemodiálise. A amostra foi composta de por 129 prontuários. Resultados: Observou-se a predominância do sexo masculino 85 (65,9%), a faixa etária foi 42 anos ou mais 97 (75,2%); cor/raça, parda 85 (65,9%), município de residência Teresina 99 (76,7%), e o estado conjugal casado 95 (73,6%). A doença com maior expressão foi hipertensão arterial sistêmica 53 (41,1%), o tempo de hemodiálise de 3 a 4 anos 43 (33,3%) e o tipo de acesso foi a fístula arteriovenosa de 118 (91,5%).Conclusão: Os resultados permitiram conhecer o perfil para auxílio do planejamento de uma assistência direcionada à prevenção e consequentemente melhora da expectativa de vida dos que são submetidos a terapia de substituição renal.
Authorreferated knowledge and behavior on disposal of domiciliary medicines / Conhecimento e comportamento autorreferidos sobre descarte domiciliar de medicamentos
Authors: Pereira Francisco Gilberto Fernandes , Sá Francisco Harles de Melo , Silva Rávida Da Rocha Lima , Silva Renata Kelly dos Santos e , Formiga Laura Maria Feitosa , Souza Eduardo Carvalho de
Published: January 2019

Objetivo: Analisar o conhecimento e comportamento autorreferidos sobre o descarte domiciliar de medicamentos. Métodos: Estudo transversal tipo survey, com dados coletados por meio de um questionário em maio de 2017, na cidade de Picos – PI, com amostra de 153 residências. Resultados: Sobre o conhecimento autorreferido apesar de 139 (90,8%) afirmar ter ciência sobre o risco ambiental, 144 (94,1%) relatou não ter conhecimento sobre local adequado de realizar o descarte. 104 (68,0%) admite que o modo como descarta os medicamentos no ambiente traz algum risco individual e 118 (77,1%) percebe a existência de risco coletivo. Quanto ao comportamento, 107 (69,9%) afirmaram já ter descartado medicamento devido ao fato do prazo de validade vencido, e a maioria afirmou realizar o descarte dentro da embalagem original e no lixo doméstico, 124 (81,0%). Conclusão: O conhecimento e comportamento autorreferidos demonstram fragilidades que comprometem a saúde pública e ambiental.
The bicycle accident in Brazil: an integrative review / Os acidentes de bicicleta no Brasil: uma revisão integrativa
Authors: Tavares Fábio Lucio , Costa Leite Franciele Marabotti , Lima Eliane de Fatima Almeida , Mendes de Melo Evandro Bernardino , Monteiro da Silva Thiago Augusto Soares , Coelho Maria José
Published: January 2019

Objetivo: analisar a produção científica acerca dos acidentes de bicicleta produzidos no Brasil. Método: revisão integrativa com propósito de responder à questão “Qual o conhecimento científico já produzido no Brasil sobre acidentes de bicicleta?” Os dados foram coletados no período de junho a agosto de 2015 nas bases MEDLINE e LILACS, artigos em português e inglês, utilizando-se os descritores: “ciclismo”, “acidentes de trânsito”, “Brasil”, “saúde pública”, “epidemiologia” e “mortalidade”. Resultados: Foram analisados 15 artigos agrupados em duas categorias: perfil epidemiológico das lesões e perfil epidemiológico dos acidentes. Conclusões: Nota-se ser necessário ampliar os estudos referentes a este tema, nos diferentes estados brasileiros, uma vez que os acidentes de bicicleta passam a ter papel importante no campo da Saúde, em especial para a Enfermagem, que irá planejar e implementar cuidados com as vítimas.
Profile of cytopathologic exams collected in a family health strategy / Perfil de exames citopatológicos coletados em estratégia de saúde da família
Authors: Dias Carolline Fredes , Micheletti Vania Celina Dezoti , Fronza Edegar , Alves Juliana da Silva , Attademo Carolinne Vargas , Strapasson Márcia Rejane
Published: January 2019

Objetivo: Descrever o perfil dos exames citopatológicos coletados em um serviço de Estratégia da Saúde da Família (ESF) na região metropolitana de Porto Alegre-RS. Métodos: Estudo transversal descritivo retrospectivo, realizado em um serviço de ESF na região metropolitana de Porto Alegre-RS. A amostra foi composta de 201 prontuários com laudos de exames de mulheres que realizaram o exame de câncer do colo do útero no período de janeiro de 2014 a dezembro de 2015. Os dados foram analisados no programa SPSS versão 21.0. Os resultados dos exames citopatológicos foram classificados de acordo com o sistema de Bethesda, 2001. Resultados: 3% tiveram resultados dentro dos limites da normalidade e 95% dos laudos registraram células atípicas de significado indeterminado, possivelmente não neoplásicas escamosas (ASC-US) e glandulares (AGUS) e 2% das mulheres apresentaram neoplasia. Conclusão: Sugere-se implantar estratégias para qualificação do processo de coleta e análise laboratorial de material citopatológico, garantindo segurança diagnóstica.
Service of nursing in intracranial pressure monitoring in patients neurocríticos / Assistência de enfermagem na monitorização da pressão intracraniana em pacientes neurocríticos
Authors: Assunção Ribeiro Kaiomakx Renato , Silva Lima Maria Luzia , Alves Ferreira Gonçalves Fernanda , Borges Maria Madalena , Nascimento Guimarães Nilza
Published: January 2019

Objetivo: Identificar por meio da literatura as intervenções de enfermagem na monitorização da pressão intracraniana em pacientes neurocríticos. Método: Revisão integrativa da literatura com busca dos artigos nas bases de dados SciELO, LILACS e PUBMED. Os artigos selecionados foram publicados entre os anos de 2007 e 2017. Resultados: Foram encontrados 94 artigos e excluídos 78 conforme critérios de inclusão. Assim 16 artigos foram usados nesta revisão. Estes apontaram que a monitorização neurológica pode ser realizada de maneira invasiva e não invasiva. Entre os métodos invasivos está a monitorização da pressão intracraniana, sendo o enfermeiro, responsável direto neste cuidado. Assim, cuidados como a elevação da cabeceira, cuidados com aspiração traqueal, cuidados com hipoxemia, coordenação e gerenciamento no cuidados de enfermagem dentre outros devem fazer parte da assistência de enfermagem. Conclusão: Os cuidados de enfermagem são indispensáveis para o paciente neurocrítico. Estes cuidados contribuem tanto para evolução positiva quanto negativa desses pacientes.
Difficulties of the nursing academics regarding the nursing care systematization applicability / Dificuldades dos acadêmicos de enfermagem na aplicabilidade da sistematização da assistência de enfermagem
Authors: Arraes Jardim Mara Julyete , Coelho Meneses Alexandra Ribeiro , Lopes de Andrade Goiabeira Yara Nayá , Menezes Elielza Guerreiro , Santana Lima Alice Bianca , Neto Manoel Luiz
Published: January 2019

Objetivo: Identificar as dificuldades dos acadêmicos de enfermagem na aplicabilidade da Sistematização da Assistência de Enfermagem. Métodos: Estudo do tipo analítico transversal, realizada com discentes do curso de graduação em Enfermagem, no período de agosto a outubro de 2014. Para análise, foi realizado cálculo das frequências e percentuais estatísticos. O estudo foi aprovado pelo CEP da Universidade do Estado do Amazonas sob Nº CAAE 36848914.0.0000.5016. Resultados: Dentre os 66 participantes, 52 (78,8%) afirmam que a SAE é utilizada nos campos de estágio e que possuem dificuldade em desenvolver as etapas do Processo de Enfermagem, principalmente, o Diagnóstico de Enfermagem 31 (47%) e prescrição de enfermagem 21 (31,8%). Além disso, os discentes reconhecem a importância da SAE para o estabelecimento de metas e como ferramenta para o cuidar. Conclusão: os acadêmicos de enfermagem têm encontrado dificuldade na aplicação no processo de enfermagem como instrumento de trabalho.
Nursing diagnoses in elderly people admitted in surgical unit / Diagnósticos de enfermagem em idosos internados em unidade cirúrgica
Authors: Martins Nidia Farias Fernandes , Silva Bárbara Tarouco da , Abreu Daiane Porto Gautério , Rosa Bibiane Moura da , Lima Juliana Piveta de , Bandeira Eliel De Oliveira
Published: January 2019

Objetivo: identificar os diagnósticos de enfermagem em idosos internados em unidade cirúrgica, determinar a prevalência desses diagnósticos, verificar associação entre os diagnósticos mais prevalentes e as características definidoras/fatores de risco. Métodos: Estudo exploratório-descritivo, transversal, quantitativo, realizado com 38 idosos internados em um hospital universitário do Sul do Brasil. A coleta de dados ocorreu por meio da aplicação do histórico de enfermagem. Para análise utilizou-se a Taxonomia II North American Nursing Diagnosis Classification e o software SPSS versão 21.0. Resultados: Os idosos internados na clínica cirúrgica apresentaram uma média de 3,4 (±1,9) diagnósticos de enfermagem e os mais prevalentes foram: Risco de Infecção (44,7%); Conhecimento Deficiente (42,1%); Dor (36,8%) e, Risco de Quedas (26,3%). Conclusão: Os diagnósticos de enfermagem possibilitam subsidiar o planejamento e a implementação das ações de enfermagem, levando em consideração as especificidades da pessoa idosa.
Self-medication in adolescents of the systemeducatinalin the city of Picos/Piauí / Automedicação em adolescentes da rede estadual de ensino na cidade de Picos/Piauí
Authors: Pereira Francisco Gilberto Fernandes , Carvalho Maria Risonete de , Figueiredo Iolanda Gonçalves de Alencar , Nascimento Danelle Da Silva , Benício Claudia Daniella Avelino Vasconcelos , Leal Jessica Denise Vieira
Published: January 2019

Objetivo: Analisar a prática de automedicação por adolescentes da rede estadual de ensino de Picos-PI. Método: Estudo descritivo e transversal, realizado com 209 adolescentes. A coleta de dados ocorreu em encontros semanais por meio de um questionário. Resultados: A faixa etária mais prevalente foi de 17 anos 94 (44,9%), 122 (58,4%) do sexo feminino, moravam com a família 129 (61,7%), na zona urbana 179 (85,7%), e católticos149 (71,2%). 209(100%) praticam a automedicação, sendo a febre o principal sintoma 120 (57,4%), e o comprimido a forma farmacêutica mais consumida 168 (57,4%). A principal motivação para automedicação foi a facilidade de conseguir medicamentos fora dos estabelecimentos de saúde 103 (49,3%), e 141 (67,5%) concordam que propagandas influenciam este comportamento. Conclusão: Os adolescentes praticam automedicação com elevada frequência, o que remete à necessidade de ações estratégicas a nível local com vistas à redução dessa prática.
Medicine dispoasal: a socio-enviromental and health issue / Descarte de medicamentos: uma questão socioambiental e de saúde
Authors: Bandeira Eliel De Oliveira , Abreu Daiane Porto Gautério , De Lima Juliana Piveta , Da Costa Cesar Francisco Silva , Costa Aline Rodrigues , Martins Nidia Farias Fernandes
Published: January 2019

Objetivos: Descrever como é realizado o descarte de medicamentos; avaliar o conhecimento de profissionais que atuam em Unidades de Saúde da Família a respeito do descarte de medicamentos. Métodos: Pesquisa qualitativa, exploratório, descritiva, realizada com 16 profissionais em quatro Unidades de Saúde da Família de um município do sul do Brasil. A coleta ocorreu por meio de entrevistas semi-estruturadas. A análise dos dados foi por meio da análise textual discursiva. Resultados: Os trabalhadores não cumprem os passos do descarte correto, a maioria desconhece a legislação vigente, os profissionais identificaram a contaminação do meio ambiente, uso indevido dos medicamentos descartados incorretamente e resistência bacteriana aos medicamentos como as principais consequências do descarte incorreto. Conclusões: Esta pesquisa pode contribuir na gestão e na assistência fazendo com que, gestores, profissionais e usuários repensem o seu fazer, melhorando a saúde das pessoas e do meio ambiente.
Knowledge of nurses about the clinical management of breastfeeding: knowledge and practices / O conhecimento do enfermeiro acerca do manejo clínico da amamentação: saberes e práticas
Authors: Souza Rosangela de Mattos Pereira de , Alves Valdecyr Herdy , Rodrigues Diego Pereira , Branco Maria Bertilla Lutterbach Riker , Lopes Fernanda de Oliveira , Santos Márcia Vieira dos
Published: January 2019

Objetivo: analisar o conhecimento dos enfermeiros na realização das estratégias para o manejo clínico da amamentação.  Método: estudo descritivo, exploratório, qualitativo, sendo participantes quarenta e sete enfermeiros das maternidades públicas da Região Metropolitana II do Estado do Rio de Janeiro, entrevistados com base em um roteiro de entrevista semiestruturada, sendo os dados coletados submetidos à análise de conteúdo na modalidade temática. Na análise, optou-se pela formulação de categorias temáticas. Resultados: no manejo clínico do aleitamento materno evidencia-se o conhecimento teórico e científico acerca da amamentação pelos enfermeiros, além de serem eles facilitadores da prática da amamentação, intervindo nos agravos resultantes da prática do aleitamento materno inadequado. Conclusão: Percebeu-se que os enfermeiros estão capacitados com competência e habilidades necessárias para favorecer a saúde da mulher e da criança em prol do sucesso da amamentação.
Single‐Step Generation of Flexible, Free‐Standing Arrays of Multimode Cylindrical Waveguides
Authors: Hudson Alexander D. , Bacus Czerysh , Whinton Marlena , Brook Michael A. , Saravanamuttu Kalaichelvi
Published: January 2019

Polymer matrices patterned with 3‐D waveguide circuitry are critical components of flexible photonics but cannot be fabricated through conventional, linear lithographic techniques. By exploiting the spontaneous filamentation and modulation instability (MI) of a uniform optical field in a range of silicone‐acrylate‐based photopolymerizable fluids, the authors report the generation of free‐standing arrays of cylindrical, multimode waveguides with tunable flexibility in a single, room‐temperature step. A broad, incandescent beam becomes unstable and spontaneously divides into a large population (≈10 000 cm−2) of microscopic filaments; each filament becomes entrapped within a self‐induced cylindrical waveguide and propagates through the medium without diverging. By spatially modulating the beam, it is possible to generate cylindrical waveguide arrays with square symmetry. By controlling the extent of cross‐linking and the relative amount of silicone surfactant in the polymerized matrix, it is possible to tune the hardness of the arrays over an order of magnitude (Shore‐OO 9 ± 5 to 94 ± 2). The authors show that flexible waveguide arrays that possess relatively low values of hardness can be reversibly compressed to up to 70% of their original lattice parameter while retaining waveguiding capacity; the arrays exhibit 100% recovery after multiple cycles of compression and decompression.
Research on In‐plane Quasi‐Static Mechanical Properties of Gradient Tetra‐Chiral Hyper‐Structures
Authors: Li Mingxuan , Lu Xiaofeng , Zhu Xiaolei , Su Xiaoping , Wu Taoyu
Published: January 2019

Chiral hyper‐structure is a family of lightweight structure with negative Poisson's ratio, which leads benefit in mechanical properties and designability. In order to further improve some mechanical properties of chiral hyper‐structures, the concept of gradient is introduced into the structure. Five groups of gradient tetra‐chiral hyper‐structure with different gradient factors are fabricated based on waterjet cutting technology, and the in‐plane quasi‐static lateral compression tests are carried out. Finite element models are developed for the in‐plane linear elastic mechanical properties and plastic deformation modes under lateral compression condition. Theoretical prediction models of elastic modulus in gradient direction and Poisson's ratio of the gradient tetra‐chiral hyper‐structure is derived based on geometric assumptions and inhomogeneous deformation mode which are verified by experiments and finite element analysis. Simultaneously, the effects of gradient factors on the deformation characteristics and mechanical behaviors of the tetra‐chiral hyper‐structure are discussed and analyzed.
Thermoresistance of p‐Type 4H–SiC Integrated MEMS Devices for High‐Temperature Sensing
Authors: Dinh Toan , Nguyen Tuan‐Khoa , Phan Hoang‐Phuong , Nguyen Quan , Han Jisheng , Dimitrijev Sima , Nguyen Nam‐Trung , Dao Dzung Viet
Published: January 2019

There is an increasing demand for the development and integration of multifunctional sensing modules into power electronic devices that can operate in high temperature environments. Here, the authors demonstrate the tunable thermoresistance of p‐type 4H–SiC for a wide temperature range from the room temperature to above 800 K with integrated flow sensing functionality into a single power electronic chip. The electrical resistance of p‐type 4H–SiC is found to exponentially decrease with increasing temperature to a threshold temperature of 536 K. The temperature coefficient of resistance (TCR) shows a large and negative value from −2100 to −7600 ppm K−1, corresponding to a thermal index of 625 K. From the threshold temperature of 536–846 K, the electrical resistance shows excellent linearity with a positive TCR value of 900 ppm K−1. The authors successfully demonstrate the integration of p–4H–SiC flow sensing functionality with a high sensitivity of 1.035 μA(m s−1)−0.5 mW−1. These insights in the electrical transport of p–4H–SiC aid to improve the performance of p–4H–SiC integrated temperature and flow sensing systems, as well as the design consideration and integration of thermal sensors into 4H–SiC power electronic systems operating at high temperatures of up to 846 K.
The Effect of High‐Pressure Torsion on Microstructure, Hardness and Corrosion Behavior for Pure Magnesium and Different Magnesium Alloys
Authors: Silva Claudio L. P. , Soares Renata B. , Pereira Pedro Henrique R. , Figueiredo Roberto B. , Lins Vanessa F. C. , Langdon Terence G.
Published: January 2019

Severe plastic deformation by high pressure torsion (HPT) is used to process and refine the grain structure of commercial purity magnesium and AZ31, AZ91, and ZK60 magnesium alloys. Transmission electron microscopy shows that the microstructure of pure magnesium is characterized by a bi‐modal grain size distribution with grains in the range of a few microns and ultrafine grains after HPT, whereas the magnesium alloys display a homogeneous ultrafine grain structure after processing. X ray diffraction analysis reveals that the AZ91 alloy displays the largest lattice microstrain and this alloy also exhibits the highest hardness after processing. The processed AZ31 and the ZK60 alloys show similar microstructures and maximum values of hardness. Contrary to earlier reports of significant improvements in the corrosion resistance of magnesium alloys in biological environments, the present results show that processing by HPT has no significant effect on the corrosion behavior of magnesium alloys in a 3.5% NaCl solution. By contrast, pure magnesium exhibits an increased corrosion resistance after HPT.
High‐Performance Ambipolar Polymers Based on Electron‐Withdrawing Group Substituted Bay‐Annulated Indigo
Authors: Yang Jie , Jiang Yaqian , Tu Zeyi , Zhao Zhiyuan , Chen Jinyang , Yi Zhengran , Li Yifan , Wang Shuai , Yi Yuanping , Guo Yunlong , Liu Yunqi
Published: January 2019

For donor–acceptor conjugated polymers, it is an effective strategy to improve their electron mobilities by introducing electron‐withdrawing groups (EWGs, such as F, Cl, or CF3) into the polymer backbone. However, the introduction of different EWGs always requires a different synthetic approach, leading to additional arduous work. Here, an effective two‐step method is developed to obtain EWG substituted bay‐annulated indigo (BAI) units. This method is effective to introduce various EWGs (F, Cl, or CF3) into BAI at different substituted positions. Based on this method, EWG substituted BAI acceptors, including 2FBAI, 2ClBAI, and 2CF3BAI, are reported for the first time. Furthermore, four polymers of PBAI‐V, P2FBAI‐V, P2ClBAI‐V, and P4OBAI‐V are developed. All the polymers show ambipolar transport properties. Particularly, P2ClBAI‐V exhibits remarkable hole and electron mobilities of 4.04 and 1.46 cm2 V−1 s−1, respectively. These mobilities are among the highest values for BAI‐based polymers.
Inherent Guanidine Nanogels with Durable Antibacterial and Bacterially Antiadhesive Properties
Authors: Han Hua , Zhu Jie , Wu De‐Qun , Li Fa‐Xue , Wang Xue‐Li , Yu Jian‐Yong , Qin Xiao‐Hong
Published: January 2019

Since bacterial infections seriously threaten human's health, considerable attention is devoted to the design of nanoscale antibacterial materials. Among them, metal nanoparticles cannot meet the requirements of durable antibacterial effects and are harmful to biological environments. In this study, environmentally friendly nanogels with durable antibacterial and antiadhesion properties are prepared by copolymerization of styrene, polycaprolactone‐hydroxyethyl methacrylate, and polyhexamethylene guanidine hydrochloride methacrylate. The resultant nanogels possess regular spherical morphologies with the size of about 200 nm. The nanogels exhibit a strong ability to kill bacteria and the mechanism is different from that of conventional antibacterial agent loaded nanoparticles. In addition, anti‐infection experiments explored by a wound model confirm the nanogels have the capability to prevent infection. Furthermore, the nanogels grafted on the surface of cotton fibers display good thermal stability, which is essential for finishing of fabrics. The cotton fabrics finished with nanogels can prevent the adhesion of bacteria by enhancing the hydrophobicity and the bacteriostatic rate. The antibacterial fabrics against Staphylococcus aureus and Escherichia coli are still more than 86% active after 50 times of mechanical washing. The biocompatible nanogels are unleachable from the antibacterial fabrics which demonstrate that they are ideal candidates for durable and environmental‐friendly nanoscaled antimicrobial materials.
Improved Interface and Electrical Properties by Inserting an Ultrathin SiO2 Buffer Layer in the Al2O3/Si Heterojunction
Authors: Kim Doyeon , Choi Jae‐Young , Ryu Sang Wook , Kim Woo‐Byoung
Published: January 2019

An ultrathin SiO2 interfacial buffer layer is formed using the nitric acid oxidation of Si (NAOS) method to improve the interface and electrical properties of Al2O3/Si, and its effect on the leakage current and interfacial states is analyzed. The leakage current density of the Al2O3/Si sample (8.1 × 10−9 A cm−2) due to the formation of low‐density SiOx layer during the atomic layer deposition (ALD) process, decreases by approximately two orders of magnitude when SiO2 buffer layer is inserted using the NAOS method (1.1 × 10−11 A cm−2), and further decreases after post‐metallization annealing (PMA) (1.4 × 10−12 A cm−2). Based on these results, the influence of interfacial defect states is analyzed. The equilibrium density of defect sites (Nd) and fixed charge density (Nf) are both reduced after NAOS and then further decreased by PMA treatment. The interface state density (Dit) at 0.11 eV decreases about one order of magnitude from 2.5 × 1012 to 7.3 × 1011 atoms eV−1 cm−2 after NAOS, and to 3.0 × 1010 atoms eV−1 cm−2 after PMA. Consequently, it is demonstrated that the high defect density of the Al2O3/Si interface is drastically reduced by fabricating ultrathin high density SiO2 buffer layer, and the insulating properties are improved.
Enhancing Efficiency and Stability of Photovoltaic Cells by Using Perovskite/Zr‐MOF Heterojunction Including Bilayer and Hybrid Structures
Authors: Lee Chia‐Chen , Chen Chih‐I , Liao Yu‐Te , Wu Kevin C.‐W. , Chueh Chu‐Chen
Published: January 2019

In this study, the effectiveness of using a perovskite/Zr‐metal–organic frameworks (MOFs) heterojunction in realizing efficient and stable inverted p–i–n perovskite solar cells (PVSCs) is demonstrated. Two types of Zr‐MOFs, UiO‐66 and MOF‐808, are investigated owing to their respectable moisture and chemical stabilities. The MOFs while serving as an interlayer in conjunction with the perovskite film are shown to possess the advantages of UV‐filtering capability and enhancing perovskite crystallinity. Consequently, the UiO‐66/MOF‐808‐modified PVSCs yield enhanced power conversion efficiencies (PCEs) of 17.01% and 16.55%, outperforming the control device (15.79%). While further utilizing a perovskite/Zr‐MOF hybrid heterojunction to fabricate the devices, the hybrid MOFs are found to possibly distribute over the perovskite grain boundary providing a grain‐locking effect to simultaneously passivate the defects and to reinforce the film's robustness against moisture invasion. As a result, the PCEs of the UiO‐66/MOF‐808‐hybrid PVSCs are further enhanced to 18.01% and 17.81%, respectively. Besides, over 70% of the initial PCE is retained after being stored in air (25 °C and relative humidity of 60 ± 5%) for over 2 weeks, in contrast to the quick degradation observed for the control device. This study demonstrates the promising potential of using perovskite/MOF heterojunctions to fabricate efficient and stable PVSCs.
Improved Efficiency and Stability of Pb/Sn Binary Perovskite Solar Cells Fabricated by Galvanic Displacement Reaction
Authors: Zhu Zonglong , Li Nan , Zhao Dongbin , Wang Liduo , Jen Alex K.‐Y.
Published: January 2019

Here, a simple and generally applicable method of fabricating efficient and stable Pb‐Sn binary perovskite solar cells (PVSCs) based on a galvanic displacement reaction (GDR) is demonstrated. Different from the commonly used conventional approaches to form perovskite precursor solutions by mixing metal halides and organic halides such as PbI2, SnI2, MAI, FAI, etc., together, the precursor solutions are formulated by reacting pure Pb‐based perovskite precursor solutions with fine Sn metal powders. After the ratios between Pb and Sn are optimized, high PCEs of 15.85% and 18.21% can be achieved for MAPb0.4Sn0.6I3 and (FAPb0.6Sn0.4I3)0.85(MAPb0.6Sn0.4Br3)0.15 based PVSCs, which are the highest PCEs among all values reported to date for Pb‐Sn binary PVSCs. Moreover, the GDR perovskite‐based PVSCs exhibit significantly improved ambient and thermal stability with encapsulation, which can retain more than 90% of their initial PCEs after being stored in ambient (relative humidity (RH) ≈50%) for 1000 h or being thermal annealed at 80 °C for more than 120 h in ambient conditions. These results demonstrate the advantage of using GDR to prepare tunable bandgap binary perovskites for devices with greatly improved performance and stability.
Single‐Ion Conducting Electrolyte Based on Electrospun Nanofibers for High‐Performance Lithium Batteries
Authors: Li Cuicui , Qin Bingsheng , Zhang Yunfeng , Varzi Alberto , Passerini Stefano , Wang Jiaying , Dong Jiaming , Zeng Danli , Liu Zhihong , Cheng Hansong
Published: January 2019

Herein, a novel electrospun single‐ion conducting polymer electrolyte (SIPE) composed of nanoscale mixed poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) and lithium poly(4,4′‐diaminodiphenylsulfone, bis(4‐carbonyl benzene sulfonyl)imide) (LiPSI) is reported, which simultaneously overcomes the drawbacks of the polyolefin‐based separator (low porosity and poor electrolyte wettability and thermal dimensional stability) and the LiPF6 salt (poor thermal stability and moisture sensitivity). The electrospun nanofiber membrane (es‐PVPSI) has high porosity and appropriate mechanical strength. The fully aromatic polyamide backbone enables high thermal dimensional stability of es‐PVPSI membrane even at 300 °C, while the high polarity and high porosity ensures fast electrolyte wetting. Impregnation of the membrane with the ethylene carbonate (EC)/dimethyl carbonate (DMC) (v:v = 1:1) solvent mixture yields a SIPE offering wide electrochemical stability, good ionic conductivity, and high lithium‐ion transference number. Based on the above‐mentioned merits, Li/LiFePO4 cells using such a SIPE exhibit excellent rate capacity and outstanding electrochemical stability for 1000 cycles at least, indicating that such an electrolyte can replace the conventional liquid electrolyte–polyolefin combination in lithium ion batteries (LIBs). In addition, the long‐term stripping–plating cycling test coupled with scanning electron microscope (SEM) images of lithium foil clearly confirms that the es‐PVPSI membrane is capable of suppressing lithium dendrite growth, which is fundamental for its use in high‐energy Li metal batteries.
Visible‐Light Driven Hydrolysis of Benzyl Halides with Water for Preparation of Benzyl Alcohols
Authors: Xu Jianbin , Liu Na , Zou Lingling , Cheng Feixiang , Shen Xianfu , Liu Teng , Lv Haiping , Khan Ruhima , Fan Baomin
Published: January 2019

Visible‐light‐mediated hydrolysis of benzyl halides has been achieved that is efficiently catalyzed by metal‐free catalyst rhodamine B. Benzyl bromides and chlorides can smoothly react with water to prepare a series of benzyl alcohol compounds in good yields.
Selective C−H Functionalization of Methane and Ethane by a Molecular SbV Complex
Authors: Koppaka Anjaneyulu , Park Sae Hume , Hashiguchi Brian G. , Gunsalus Niles J. , King Clinton R. , Konnick Michael M. , Ess Daniel H. , Periana Roy A.
Published: January 2019

Owing to the strong nonpolar bonds involved, selective C−H functionalization of methane and ethane to esters remains a challenge for molecular homogeneous chemistry. We report that the computationally predicted main‐group p‐block SbV(TFA)5 complex selectively functionalizes the C−H bonds of methane and ethane to the corresponding mono and/or diol trifluoroacetate esters at 110–180 °C with yields for ethane of up to 60 % with over 90 % selectivity. Experimental and computational studies support a unique mechanism that involves SbV‐mediated C−H activation followed by functionalization of a SbV‐alkyl intermediate.
Selektive Funktionalisierung von Graphen an defektaktivierten Bereichen durch Arylazocarbonsäure‐tert‐butylester
Authors: Halbig Christian E. , Lasch Roman , Krüll Jasmin , Pirzer Anna S. , Wang Zhenping , Kirchhof Jan N. , Bolotin Kirill I. , Heinrich Markus R. , Eigler Siegfried
Published: January 2019

Die Entwicklung vielseitiger Funktionalisierungskonzepte für Graphen steht derzeit im Fokus der Forschung. Mittels Oxo‐Funktionalisierung von Graphit wird die gesamte Oberfläche von Graphen für die C‐C‐Bindungsbildung zugänglich, um Addenden einzuführen. Hier stellen wir die Arylierung von Graphen durch Arylazocarbonsäure‐tert‐butylester vor, die nach Aktivierung durch Säuren Arylradikale erzeugen. Überraschenderweise korreliert der Funktionalisierungsgrad mit der Konzentration der Strukturdefekte im Graphengitter. Folglich ist Graphen inert, wenn es frei von Defekten ist. Die Reaktion kann auch auf in Lösemitteln dispergiertes Graphen angewendet werden und führt zu einer bitopen Funktionalisierung. Ist Graphen auf Oberflächen abgeschieden wird eine monotope Funktionalisierung erreicht. Da Arylazocarbonsäure‐tert‐butylester vielfältig an verschiedene Moleküle gebunden werden kann, ebnet das vorgestellte Verfahren den Weg zu funktionellen Graphenderivaten, wobei die Defektdichte im Graphen den Grad der Funktionalisierung bestimmt.
Spectroscopic and Computational Evidence of Intramolecular AuI⋅⋅⋅H+−N Hydrogen Bonding
Authors: Straka Michal , Andris Erik , Vícha Jan , Růžička Aleš , Roithová Jana , Rulíšek Lubomír
Published: January 2019

Despite substantial evidence of short Au⋅⋅⋅H−X contacts derived from a number of X‐ray structures of AuI compounds, the nature of AuI⋅⋅⋅H bonding in these systems has not been clearly understood. Herein, we present the first spectroscopic evidence for an intramolecular AuI⋅⋅⋅H+−N hydrogen bond in a [Cl−Au−L]+ complex, where L is a protonated N‐heterocyclic carbene. The complex was isolated in the gas phase and characterized with helium‐tagging infrared photodissociation (IRPD) spectra, in which H+−N‐mode‐derived bands evidence the intramolecular AuI⋅⋅⋅H+−N bond. Quantum chemical calculations reproduce the experimental IRPD spectra and allow to characterize the intramolecular Au⋅⋅⋅H+−N bonding with a short rAu⋅⋅⋅H distance of 2.17 Å and an interaction energy of approximately −10 kcal mol−1. Various theoretical descriptors of chemical bonding calculated for the Au⋅⋅⋅H+−N interaction provide strong evidence for a hydrogen bond of moderate strength.
Sulfilimine als vielseitige Nitrentransfer‐Reagenzien: Einfacher Zugang zu vielfältigen aza‐Heterocyclen
Authors: Tian Xianhai , Song Lina , Rudolph Matthias , Rominger Frank , Oeser Thomas , Hashmi A. Stephen K.
Published: January 2019

Wir berichten hier über die neue Synthese verschiedener biologisch wichtiger aza‐Heterocyclen mittels Sulfiliminen als Nitrentransfer‐Reagenzien. Diese Klasse von schwefelbasierten aza‐Yliden ist bisher für einen Gold‐Nitren‐Transfer nicht erfolgreich genutzt worden. In dieser Arbeit wird die effiziente Generierung von α‐Imino‐Gold‐Carbenen über eine N‐S‐Bindungsspaltung in Sulfiliminen gezeigt. Die Goldcarbene gehen C‐H‐Insertionen, Cyclopropanierungen und nukleophile Angriffe ein, die zu Indolen (44 Beispiele), 3‐Azabicyclo[3.1.0]hexan‐2‐iminen (24 Beispiele) und Imidazolen (3 Beispiele) führen. Diese Arbeit präsentiert die bisher unbekannte goldkatalysierte Reaktion zwischen Alkinen und Schwefelyliden. Zudem wird das erste Beispiel einer aza‐Heterocyclisierung über intermolekularen Nitrentransfer, gefolgt von der Cyclopropanierung des α‐Imino‐Goldcarbens, gezeigt. Sogar die unerwartete Synthese eines 4‐Acylchinolins (3 Beispiele) aus 2‐Acylphenylsulfiliminen und propargylischen Silyletherderivaten über eine 1,2‐Hydridverschiebung auf das α‐Imino‐Goldcarben und eine nachfolgende Mukaiyama‐Aldol‐Cyclisierung wurde entdeckt.
Structural Snapshots of Cluster Growth from {U6} to {U38} During the Hydrolysis of UCl4
Authors: Chatelain Lucile , Faizova Radmila , Fadaei‐Tirani Farzaneh , Pécaut Jacques , Mazzanti Marinella
Published: January 2019

Herein we report the assembly of large uranium(IV) clusters with novel nuclearities and/or shapes from the controlled hydrolysis of UCl4 in organic solution and in the presence of the benzoate ligands. {U6}, {U13}, {U16}, {U24}, {U38} oxo and oxo/hydroxo clusters were isolated and crystallographically characterized. These structural snapshots indicate that larger clusters are slowly built from the condensation of octahedral {U6} building blocks. The uranium/benzoate ligand ratio, the reaction temperature and the presence of base play an important role in determining the structure of the final assembly. Moreover, the isolation of different size cluster {U6} (few hours), {U16} (3 days), {U24} (21 days) from the same solution in a chosen set of conditions shows that the assembly of uranium oxo clusters in hydrolytic conditions is time dependent.
Umpolung Reactivity of Ynamides: An Unconventional [1,3]‐Sulfonyl and [1,5]‐Sulfinyl Migration Cascade
Authors: Prabagar B. , Mallick Rajendra K. , Prasad Rangu , Gandon Vincent , Sahoo Akhila K.
Published: January 2019

A regioselective sulfonyl/sulfinyl migration cycloisomerization cascade of alkyne‐tethered ynamides is developed in the presence of XPhosgold catalyst. This reaction is the first example of a general [1,3]‐sulfonyl migration from the nitrogen center to the β‐carbon atom of ynamides, followed by umpolung 5‐endo‐dig cyclization of the ynamide α‐carbon atom to the gold‐activated alkyne, and final deaurative [1,5]‐sulfinylation. This process allows the synthesis of peripherally decorated unconventional 4‐sulfinylated pyrroles with broad scope from N‐propargyl‐tethered ynamides. In contrast, N‐homopropargyl‐tethered ynamides undergo intramolecular tetradehydro Diels–Alder reaction to provide 2,3‐dihydro‐benzo[f]indole derivatives. Control experiments and density‐functional theory studies were used to study the reaction pathways.
Chemical Regulation of DNA i‐Motifs for Nanobiotechnology and Therapeutics
Authors: Debnath Manish , Fatma Khushnood , Dash Jyotirmayee
Published: January 2019

DNA sequences rich in cytosine have the propensity, under acidic pH, to fold into four‐stranded intercalated DNA structures called i‐motifs. Recent studies have provided significant breakthroughs that demonstrate how chemists can manipulate these structures for nanobiotechnology and therapeutics. The first section of this Minireview discusses the development of advanced functional nanostructures by synthetic conjugation of i‐motifs with organic scaffolds and metal nanoparticles and their role in therapeutics. The second section highlights the therapeutic targeting of i‐motifs with chemical scaffolds and their significance in biology. For this, first we shed light on the long‐lasting debate regarding the stability of i‐motifs under physiological conditions. Next, we present a comparative analysis of recently reported small molecules for specifically targeting i‐motifs over other abundant DNA structures and modulating their function in cellular systems. These advances provide new insights into i‐motif‐targeted regulation of gene expression, telomere maintenance, and therapeutic applications.
The Bacterial [Fe]‐Hydrogenase Paralog HmdII Uses Tetrahydrofolate Derivatives as Substrates
Authors: Watanabe Tomohiro , Wagner Tristan , Huang Gangfeng , Kahnt Jörg , Ataka Kenichi , Ermler Ulrich , Shima Seigo
Published: January 2019

[Fe]‐hydrogenase (Hmd) catalyzes the reversible hydrogenation of methenyl‐tetrahydromethanopterin (methenyl‐H4MPT+) with H2. H4MPT is a C1‐carrier of methanogenic archaea. One bacterial genus, Desulfurobacterium, contains putative genes for the Hmd paralog, termed HmdII, and the HcgA–G proteins. The latter are required for the biosynthesis of the prosthetic group of Hmd, the iron–guanylylpyridinol (FeGP) cofactor. This finding is intriguing because Hmd and HmdII strictly use H4MPT derivatives that are absent in most bacteria. We identified the presence of the FeGP cofactor in D. thermolithotrophum. The bacterial HmdII reconstituted with the FeGP cofactor catalyzed the hydrogenation of derivatives of tetrahydrofolate, the bacterial C1‐carrier, albeit with low enzymatic activities. The crystal structures show how Hmd recognizes tetrahydrofolate derivatives. These findings have an impact on future biotechnology by identifying a bacterial Hmd paralog.
One‐Dimensional Fe2P Acts as a Fenton Agent in Response to NIR II Light and Ultrasound for Deep Tumor Synergetic Theranostics
Authors: Liu Yang , Zhen Wenyao , Wang Yinghui , Liu Jianhua , Jin Longhai , Zhang Tianqi , Zhang Songtao , Zhao Ying , Song Shuyan , Li Chengyu , Zhu Junjie , Yang Yang , Zhang Hongjie
Published: January 2019

The stringent reaction conditions for an effective Fenton reaction (pH range of 3–4) hinders its application in cancer therapy. Therefore, how to improve the efficiency of the Fenton reaction in a tumor site has been the main obstacle in chemodynamic therapy (CDT). Herein, we report biocompatible one‐dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)‐ and photothermal (PT)‐enhanced Fenton properties and excellent photothermal conversion efficiency (56.6 %) in the NIR II window, showing synergistic therapeutic properties. Additionally, the high photothermal conversion efficiency and excellent traverse relaxivity (277.79 mm−1 s−1) of the FP NRs means they are excellent photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) agents. This is the first report on exploiting the response of metallic phosphides to NIR II laser (1064 nm) and ultrasound to improve the CDT effect with a high therapeutic effect and PA/MR imaging.
Anchoring an Artificial Solid–Electrolyte Interphase Layer on a 3D Current Collector for High‐Performance Lithium Anodes
Authors: Li Panlong , Dong Xiaoli , Li Chao , Liu Jingyuan , Liu Yao , Feng Wuliang , Wang Congxiao , Wang Yonggang , Xia Yongyao
Published: January 2019

The application of Li anodes is hindered by dendrite growth and side reactions between Li and electrolyte, despite its high capacity and low potential. A simple approach for this challenge is now demonstrated. In our strategy, the garnet‐type Li6.4La3Zr1.4Ta0.6O12 (LLZTO)‐based artificial solid–electrolyte interphase (SEI) is anchored on Cu foam by sintering the Cu foam coated with LLZTO particles. The heat treatment leads to the interdiffusion of Cu and Ta2O5 at the Cu/LLZTO interface, through which LLZTO layer is fixed on Cu foam. 3D structure lowers the current density, and meanwhile the SEI reduces the contact of Li and electrolyte. Furthermore, the anchoring construction can endure Li‐deposition‐induced volume change. Therefore, LLZTO‐modified Cu foam shows much improved Li plating/stripping performance, including long lifespan (2400 h), high rate (maximum current density of 20 mA cm−2), high areal capacity (8 mA h cm−2 for 100 cycles), and high efficiency (over 98 %).
Stereoselective Total Synthesis of Eburnane‐Type Alkaloids Enabled by Conformation‐Directed Cyclization and Rearrangement
Authors: Li Guang , Piemontesi Cyril , Wang Qian , Zhu Jieping
Published: January 2019

Controlling the cis C20/C21 relative stereochemistry remains an unsolved issue in the synthesis of eburnane‐type indole alkaloids. Provided herein is a simple solution to this problem by developing a unified and diastereoselective synthesis of four representative members of this class of natural products, namely, eburnamonine, larutensine, terengganensine B, and melokhanine E. The synthesis features the following key steps: a) an α‐iminol rearrangement transforming the 3‐hydroxyindolenine into spiroindolin‐3‐one, b) a highly diastereoselective conformation‐directed cyclization leading to the melokhanine skeleton with the desired C20/C21 cis stereochemistry, and c) either an aza‐pinacol or an unprecedented α‐aminoketone rearrangement converting spiroindolinone back into the indole skeleton.
Asymmetric and Geometry‐Selective α‐Alkenylation of α‐Amino Acids
Authors: Abas Hossay , Mas‐Roselló Josep , Amer Mostafa Mahmoud , Durand Derek J. , Groleau Robin R. , Fey Natalie , Clayden Jonathan
Published: January 2019

Both E‐ and Z‐N′‐alkenyl urea derivatives of imidazolidinones may be formed selectively from enantiopure α‐amino acids. Generation of their enolate derivatives in the presence of K+ and [18]crown‐6 induces intramolecular migration of the alkenyl group from N′ to Cα with retention of double bond geometry. DFT calculations indicate a partially concerted substitution mechanism. Hydrolysis of the enantiopure products under acid conditions reveals quaternary α‐alkenyl amino acids with stereodivergent control of both absolute configuration and double bond geometry.
Constructing Mononuclear Palladium Catalysts by Precoordination/Solvothermal Polymerization: Recyclable Catalyst for Regioselective Oxidative Heck Reactions
Authors: Li Wen‐Hao , Li Cun‐Yao , Xiong Huan‐Yan , Liu Yang , Huang Wen‐Yong , Ji Guang‐Jun , Jiang Zheng , Tang Hai‐Tao , Pan Ying‐Ming , Ding Yun‐Jie
Published: January 2019

Heterogeneous, metal, single‐site catalysts often exhibit higher catalytic performance than other catalysts because of their maximized atom efficiency of 100 %. Reported herein is a precoordination/solvothermal polymerization strategy to fabricate a stable mononuclear Pd‐metalized porous organic polymer catalyst (Pd@POP). Pd@POP was easy to use in regioselective organic reactions because the internal structure of this Pd@POP can be easily modified. The catalyst was used to solve the intractable regioselectivity problems of Heck reactions. Pd@POP‐9 can efficiently activate the ends of olefins, thereby leading to high selectivity for substitution at the external position. To understand the reason underlying the high selectivity and activity of the catalyst, the systemic characterization of Pd@POP‐9 and density‐functional theory calculations were conducted. This Heck reaction is the first to be catalyzed by a recyclable mononuclear metal catalyst with unprecedented catalytic activity and regioselectivity.
Enantioselective Synthesis of 3,3′‐Diaryl‐SPINOLs: Rhodium‐Catalyzed Asymmetric Arylation/BF3‐Promoted Spirocyclization Sequence
Authors: Yin Long , Xing Junhao , Wang Yuhan , Shen Yue , Lu Tao , Hayashi Tamio , Dou Xiaowei
Published: January 2019

The enantioselective synthesis of a series of C2‐symmetric 3,3′‐diarylated 1,1′‐spirobiindane‐7,7′‐diols (3,3′‐diaryl‐SPINOLs) was developed by sequential Rh‐catalyzed twofold asymmetric conjugate arylation/BF3‐promoted diastereoselective spirocyclization (>20:1 d.r. and >99 % ee for all examples). Some phosphoramidite ligands were prepared from the 3,3′‐Ph‐SPINOL and applied to several catalytic asymmetric reactions, and the 3,3′‐diarylated ligands showed higher enantioselectivities than the privileged nonsubstituted ligands.
Isolation, synthesis, and cytotoxicity evaluation of two impurities in nomegestrol acetate
Authors: Xie Bao‐Cheng , Song Shu‐Yong , Xie Xiao‐Yang , Sun Yu‐Tong , Zhang Xiao‐Yuan , Xu Dao‐Hua , Huang Yun‐Sheng
Published: January 2019

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth‐generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6‐methylene to 6‐methyl‐6,7‐unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF‐7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 μM). NOMAc and impurity A showed cytotoxicity to L02, MCF‐7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested.