bluuebunny/crossref_metadata_2025 huggingface dataset:
5-Year Survival after Endobronchial Coil Implantation: Secondary Analysis of the First Randomised Controlled Trial, RESET
Authors: Garner Justin L. , Kemp Samuel V. , Srikanthan Karthi , Caneja Cielito , Zoumot Zaid , Roberts Cara , Banya Winston , Chaudhuri Rekha , Bicknell Stephen , Ross Ewen , LaPrad Adam S. , Shah Pallav L.
Published: January 2020

Background: Lung volume reduction surgery is a proven treatment for emphysematous patients with hyperinflation, but the precarious health of candidates has prompted development of less invasive approaches. Bronchoscopic implanted endobronchial coils, shape-memory nitinol filaments, shrink emphysematous lung tissue to restore elastic recoil and to tether airways to maintain patency. Studies have demonstrated an acceptable safety profile and improvements in lung function, exercise capacity, and quality of life out to 3 years. Volume reduction is key. However, data for longer-term survival are limited. Objective: The aim of this study was to establish the 5-year overall and transplant-free survivals of subjects whose procedure in the first randomized controlled trial, RESET, achieved clinically meaningful reduction in residual volume (RV). Methods: Patients and their primary care doctors were contacted to confirm vital status and history of additional interventions. Death certificates were acquired via the General Registry Office. Survival time was calculated for responders achieving a reduction of ≥10% in RV compared to non-responders. Results: 39 patients completed the planned bilateral sequential treatments. Six patients received unilateral implants. At 5 years, 22 patients had died. The overall survivals at 1, 2, 3, 4 and 5 years were 88.9, 88.9, 77.8, 64.4 and 50.6%, respectively. Two patients underwent lung transplantation at 52 and 59 months and were alive at 5 years. The transplant-free (TF) survivals at 1, 2, 3, 4 and 5 years were 88.9, 88.9, 77.8, 64.4 and 46.7%, respectively. Volume reduction responders (n = 18) at 3 months had a 5-year TF survival of 66.7% compared to 36.4% for non-responders (n = 22; p = 0.07). Higher baseline inspiratory capacity (HR 0.13, 95% CI 0.02–0.73; p = 0.02) and partial pressure of oxygen (pO2) (HR 0.57, 95% CI 0.38–0.86; p < 0.01) values were predictive of survival for the entire cohort and were not influenced by age. Conclusions: Endobronchial coil implantation appears to confer a 5-year survival advantage for those who achieved a 10% reduction in RV at 3 months. Ongoing trials are designed to clarify the mechanisms of action of coils and to refine patient selection.
Thioredoxin1 Inactivation Mediates the Impairment of Ischemia-Induced Angiogenesis and Further Injury in Diabetic Myocardium
Authors: Hou Rongrong , Shen Mingzhi , Wang Rutao , Liu Haitao , Gao Chao , Xu Jing , Tao Ling , Yin Zhiyong , Yin Tao
Published: January 2020

Diabetes mellitus (DM)-induced impairment of collateral formation has been demonstrated in subjects with coronary artery disease, which contributes to unfavorable prognosis among diabetic individuals. In our previous studies, thioredoxin1 (Trx1) activity was shown to be decreased in diabetic cardiac tissues, but the reason of Trx1 inactivation and whether it mediates the impaired angiogenesis in ischemic myocardium is still to be identified. As thioredoxin-interacting protein (TXNIP), an endogenous inhibitor of Trx, is overexpressed in DM due to carbohydrate response element within its promoter, we hypothesized that inhibition of Trx1 by enhanced TXNIP expression in endothelial cells may play a role in hyperglycemia-induced impairment of angiogenesis. In the present study, we found that high glucose-mediated increase of TXNIP expression and TXNIP-Trx1 interaction induced the impairment in endothelial cell function and survival, since these detrimental effects are rescued by silencing TXNIP with small interfering RNA. In diabetic mice, TXNIP knockdown or recombinant human Trx1 treatment counteracted the impairment of angiogenesis, alleviated myocardial ischemic injury, and improved survival rate. All these data implicate that TXNIP upregulation and subsequently the increased formation of TXNIP-Trx1 complex is a novel pathologic pathway by which DM induces insufficient angiogenesis and thereby exacerbates myocardial ischemia injury.
Peroral Endoscopic Myotomy in a Patient with Achalasia Cardia with Prior Heller’s Myotomy
Authors: Miftahussurur Muhammad , Tandan Manu , Makmun Dadang , Nabi Zaheer
Published: January 2020

Achalasia cardia is an esophageal myenteric plexus disorder characterized by absence of or incomplete lower esophageal sphincter relaxation and esophageal aperistalsis; Heller’s myotomy is the main treatment of choice due to a lower failure rate. Recently, peroral endoscopic myotomy (POEM) has been reported as an alternative treatment for achalasia due to persistent symptoms after Heller’s myotomy. An Indian male, aged 18 years, was admitted to the hospital due to dysphagia which had started more than 3 years ago. He also complained of occasional regurgitation and retrosternal pain with Eckardt score 6. Heller’s myotomy was performed 2 years ago. Barium swallow showed achalasia cardia and upper gastrointestinal endoscopy found liquid residue and resistance at the gastroesophageal junction. Esophageal manometry is concluded as achalasia cardia type II with a median integrated relaxation pressure (IRP) of 25.6 mm Hg. He underwent POEM; with the help of a submucosal tunnel, an extension of up to 1 cm beyond the gastroesophageal junction could be achieved with a posterior orientation of myotomy. There were no adverse events after the POEM procedure. He was treated with a soft diet for 10 days and other supportive treatments. Following POEM, barium swallow showed a significant improvement and esophageal manometry exhibited that the basal lower esophageal sphincter pressure was normal with complete relaxation on swallowing and normal median IRP. The post-procedure Eckardt score was 0. We reported an achalasia patient who received POEM after unsuccessful Heller’s myotomy and showed clinical improvement.
Multicenter Study on Differential Human Neutrophil Antigen 2 Expression and Underlying Molecular Mechanisms
Authors: Flesch Brigitte K. , Reil Angelika , Nogués Núria , Canals Carme , Bugert Peter , Schulze Torsten J. , Huiskes Elly , Porcelijn Leendert , Höglund Petter , Ratcliffe Paul , Schönbacher Marlies , Kerchrom Hans , Kellershohn Josina , Bayat Behnaz
Published: January 2020

Background: The human neutrophil antigen 2 (HNA-2), which is expressed on CD177, is undetectable in 3–5% of the normal population. Exposure of these HNA-2null individuals to HNA-2-positive cells can cause immunization and pro­duction of HNA-2 antibodies, which can induce immune neutropenia and transfusion-related acute lung injury. In HNA-2-positive individuals, neutrophils are divided into a CD177pos. and a CD177neg. subpopulation. The molecular background of HNA-2 deficiency and the bimodal expression pattern, however, are not completely decoded. Study Design: An international collaboration was conducted on the genetic analysis of HNA-2-phenotyped blood samples, including HNA-2-deficient individuals, mothers, and the respective children with neonatal immune neutropenia and regular blood donors. Results: From a total of 54 HNA-2null individuals, 43 were homozygous for the CD177*787A>T substitution. Six carried the CD177*c.1291G>A single nucleotide polymorphism. All HNA-2-positive samples with >40% CD177pos. neutrophils carried the *787A wild-type allele, whereas a lower rate of CD177pos. neutrophils was preferentially associated with *c.787AT heterozygosity. Interestingly, only the *c.787A allele sequence was detected in complementary DNA (cDNA) sequence analysis carried out on all *c.787AT heterozygous individuals. However, cDNA analysis after sorting of CD177pos. and CD177neg. neutrophil subsets from HNA-2-positive individuals showed identical sequences, which makes regulatory elements within the promoter unlikely to affect CD177 gene transcription in different CD177 neutrophil subsets. Conclusion: This comprehensive study clearly demonstrates the impact of single nucleotide polymorphisms on the expression of HNA-2 on the neutrophil surface but challenges the hypothesis of regulatory epigenetic effects being implicated in the bimodal CD177 expression pattern.
Evaluation von Stressprävention und Stressbewältigung mittels epigenetischer Marker
Authors: Stoffel Martin , Gardini Elena , Ehrenthal Johannes C. , Abbruzzese Elvira , Ditzen Beate
Published: January 2020

Chronischer oder traumatischer Stress kann psychische Störungen und körperliche Erkrankungen begünstigen oder sogar verursachen. Ergebnisse aus der Grundlagenforschung zeigen, dass Stress zu einer Dysregulation wichtiger körperlicher Stresssysteme führen kann, welche diese Prozesse vermutlich vermitteln. Hierauf aufbauend wurden Interventionen zur Prävention oder zum Umgang mit Stress entwickelt, deren Wirkung mittels verschiedener Indikatoren dieser Stresssysteme evaluiert werden kann. In den letzten Jahren zeigten Ergebnisse aus Tier- und Humanstudien, dass sich Stress auch auf epigenetische Signaturen auswirken kann. Die funktionellen Konsequenzen dieser Veränderungen, darunter eine veränderte Expression der betroffenen Gene, wurden zudem als Modulatoren der psycho­biologischen Stressantwort beschrieben. Eine Reihe erster Pionierstudien zeigt nun, dass stressassoziierte epigenetische Prozesse durch psychologische Interventionen, darunter Stressprävention und Stressbewältigung, verhindert oder sogar umgekehrt werden können. In der vorliegenden Übersichtsarbeit werden (1) relevante epigenetische Mechanismen beschrieben, (2) eine Übersicht zum Zusammenhang von Epigenetik und Stress dargestellt und (3) erläutert, wie epigenetische Prozesse durch psychologische Interventionen beeinflusst werden könnten.
Intraocular Lens Dislocation into the Anterior Chamber because of Repeated Eye-Poking in a Patient with Leber’s Congenital Amaurosis
Authors: Al-Owaid Abdullah A. , Alarfaj Motazz A.  , Alarfaj Faris A. , Awad Abdulaziz
Published: January 2020

The dislocation of a posterior chamber intraocular lens (PC IOL) because of constant eye rubbing is unusual and has never been reported in a child with Leber’s congenital amaurosis (LCA). A 4-year-old full-term girl with an ocular history of LCA presented to the emergency room with a single-piece PC IOL dislocated into the anterior chamber (AC) of the left eye. There was no history of trauma or any other surgical intervention. A specific behavior known as Franceschetti’s oculo-digital sign is a characteristic feature of LCA; this sign consists of repeated pressing, poking, and rubbing of the eyes with knuckles and fingers to stimulate the photoreceptors. This behavior caused the dislocation of the PC IOL into the AC. The dislocated IOL was explanted, and the patient was provided with aphakic glasses.
Effect of L-Carnitine on Amino Acid Metabolism in Elderly Patients Undergoing Regular Hemodialysis
Authors: Kido Jun , Inoue Hironobu , Shimotsu Hiroshi , Yoshida Yutaka , Suzuki Yosuke , Nakamura Kimitoshi , Endo Fumio , Matsumoto Shirou
Published: January 2020

Introduction: Among patients regularly undergoing hemodialysis, hypocarnitinaemia often develops as a consequence of inadequate dietary intake, reduced synthesis in the body, and considerable losses during hemodialysis. Objectives: To evaluate the effects of L-carnitine supplementation on patients with end-stage kidney disease (ESKD) who underwent hemodialysis. Methods: Thirty-one patients with ESKD, comprising 18 men and 13 women, with a median age of 72 (range 58–89) years, who underwent regular hemodialysis received treatment with L-carnitine for 1 year. The total and free carnitine, acylcarnitine, and amino acids (AA) levels before and after L-carnitine treatment were analyzed, and the blood biochemistry results and clinical profiles of the subjects were compared before and after treatment. Results: The median (interquartile range [IQR]) serum total and free carnitine and acylcarnitine levels significantly increased from 34.5 (28.2–44.3), 20.9 (15.8–27.6), and 14.1 (11.2–17.6) µmol/L, respectively to 407.4 (371.6–493.5), 270.2 (228.3–316.0), and 155.0 (136.1–168.5) µmol/L, respectively, after treatment (all p < 0.001). The median (IQR) blood valine, tyrosine, phenylalanine, and citrulline levels increased from 0.94 (0.80–1.09), 0.45 (0.39–0.55), 0.61 (0.56–0.79), and 1.04 (0.79–1.26) mg/dL, respectively to 1.24 (1.13–1.54), 0.76 (0.62–0.85), 0.90 (0.70–1.04), and 1.22 (0.92–1.39) mg/dL, respectively, following L-carnitine treatment (p < 0.001, p < 0.001, p = 0.002, and p = 0.030, respectively); however, the median (IQR) blood arginine level decreased from 0.20 (0.13–0.24) to 0.09 (0.06–0.14) mg/dL after treatment (p < 0.001). The median (IQR) percentage fractional shortening (41.5 vs. 41.9%; p = 0.012) and left ventricular ejection fraction (65.2 vs. 67.3%; p = 0.036) increased significantly following treatment. Conclusions: L-Carnitine increased the blood acylcarnitine levels, enhanced fatty acid metabolism, and affected AAs metabolism; this may be beneficial for energy production within the cardiac and skeletal muscles.
O uso do BIM para avaliação do desempenho dos edifícios
Authors: Leitner Drielle Sanchez , Scheer Sergio , Santos Adriana De Paula Lacerda
Published: January 2020

O objetivo do presente estudo é estabelecer uma conexão entre o BIM e o desempenho das edificações, sua busca e sua avaliação, por meio de uma Revisão Sistemática da Literatura (RSL). Foram utilizadas duas bases de dados eletrônicas (Science Direct e Scopus), e foram incluídos artigos de periódicos e congressos escritos em inglês. A RSL resultou na inclusão de 79 artigos, publicados de 2006 a 2017, usados na construção do panorama BIM – desempenho. De acordo com a análise bibliométrica, o assunto em discussão vem crescendo desde 2014. Por meio da leitura dos artigos percebeu-se que existem quatro abordagens principais em que o BIM foi usado na análise de características do desempenho das edificações: um grupo de publicações utilizou as ferramentas BIM em conjunto com as ferramentas de simulações de desempenho; outros artigos discutiram sobre a interoperabilidade de ferramentas BIM e ferramentas de simulação; um terceiro grupo buscou integrar o BIM com dados de sensores; e o último grupo identificado discutiu a integração de ferramentas BIM com sistemas de classificação de construção sustentável. As quatro abordagens foram discutidas o que mostrou que o BIM está sendo usado na busca por um melhor desempenho das edificações e também na investigação do desempenho real das edificações. A primeira abordagem contou com mais da metade das publicações identificadas. Não foi possível identificar uma ferramenta de simulação predominante, seja globalmente seja por tipo de simulação de desempenho. Por outro lado, a ferramenta BIM mais utilizada, independentemente da proposta da publicação, foi a Autodesk Revit.
Estudo da relação arquiteto-cliente em projetos de baixa complexidade
Authors: Bunder Jeferson , Ono Rosaria
Published: January 2020

A maioria dos arquitetos brasileiros atua nas áreas de concepção de projetos, serviços relacionados à execução de obras e arquitetura de interiores. Em geral, esses profissionais se comprometem, por meio de suas relações com seus clientes, com o fornecimento de serviços dentro de prazos, escopos e custos pré-estabelecidos. Esta pesquisa tem o objetivo de investigar e compreender a relação entre o arquiteto e o cliente, focado na comunicação, considerando os caminhos que levam aos acertos, ou aos desvios, e que resultarão no sucesso do serviço prestado. O método utilizado, aliado a revisão bibliográfica, é de estudos de caso múltiplos, constituído de um caso-piloto e nove estudos de caso. A delimitação da pesquisa está no trabalho do profissional de arquitetura, que atua com projetos e obras de baixa complexidade, em pequenos escritórios e que possui relação direta com o seu cliente. Como resultado verificou-se que o sucesso da gestão desses serviços não depende apenas de um rígido controle de parâmetros racionais do seu processo projetual e executivo, como acertos ou desvios de prazos, escopo e custos pré-estabelecidos, mas também do cumprimento de parâmetros subjetivos idealizados pelo arquiteto e pelo cliente.
Documentação digital do patrimônio arquitetônico
Authors: Rodrigues Rosemary Lopes , Agostinho Carlos Jacinto
Published: January 2020

Este artigo investiga o processo de preservação arquitetônica a partir da aplicação de técnicas fotogramétricas para a documentação digital. Adotou-se, como objeto empírico, a Igreja Nossa Senhora Mãe dos Homens, localizada em Coqueiro Seco, no estado de Alagoas, Brasil. Datada de 1790, consiste em um dos exemplares da arquitetura religiosa mais antigo do estado, protegida pela União por meio do tombamento desde 2011 e com previsão de uma obra de restauro em suas estruturas. O objetivo deste artigo é documentar o estado anterior à intervenção na igreja, descrevendo o processo de documentação patrimonial e utilizando como recurso técnicas fotogramétricas mistas. Metodologicamente, foram realizadas pesquisas bibliográficas e documentais; levantamentos fotográficos da Igreja, seguindo os princípios da restituição fotogramétrica interativa e do Dense Stereo Matching (DSM); construção de modelos geométricos por meio do software PhotoModeler Scanner e vetorização das fachadas utilizando-se uma ferramenta CAD. Como resultados, registraram-se as fachadas principais do bem com a fotogrametria e disponibilizou-se a documentação produzida. Além disso, o artigo traz uma reflexão acerca das limitações das técnicas utilizadas, enfatizando a relevância do uso híbrido das tecnologias disponíveis para o registro e democratização do acesso à documentação da arquitetura de interesse cultural.
Desenvolvimento e avaliação de réplicas em resinas de bens do patrimônio cultural com uso de digitalização 3D e fabricação digital
Authors: Bonfada Carolina De Freitas , Kauffmann Aline Reis , Silva Fabio Pinto da
Published: January 2020

O uso das novas tecnologias digitais viabiliza estratégias essenciais para a documentação e preservação do patrimônio cultural. A utilização da digitalização 3D permite o registro digital de obras do patrimônio, ao passo que esses registros possibilitam o desenvolvimento de análises e estudos. As digitalizações podem ainda ser utilizadas para a produção de réplicas fidedignas de obras danificadas ou furtadas. Este trabalho tem por objetivo a análise dimensional de réplicas produzidas em resinas a partir do uso da digitalização 3D em conjunto com técnicas de fabricação digital. Nesse sentido, foi adotada uma metodologia de pesquisa experimental, a partir de um estudo de caso. Para tanto, as placas em bronze do monumento a Bento Gonçalves (Porto Alegre, RS) foram digitalizadas em 3D e um trecho de uma delas foi selecionado para a realização de ensaios de fabricação digital. Foram produzidas duas peças, uma pelo processo de usinagem por comando numérico computadorizado (CNC) e outra por impressão 3D por filamento fundido (FFF). A peça usinada foi selecionada para a construção de um molde em silicone para posterior produção das réplicas em resina. Todas as etapas do processo de produção das réplicas foram digitalizadas para a realização de análise dimensional. Os resultados demonstraram que a usinagem CNC é o processo mais preciso dimensionalmente para a produção das réplicas das placas. Entre os materiais ensaiados, a resina de poliéster cristal é a mais apropriada para produção de uma eventual peça de reposição.
Early Initiation of Direct Oral Anticoagulants After Onset of Stroke and Short- and Long-Term Outcomes of Patients With Nonvalvular Atrial Fibrillation
Authors: Mizoguchi Tadataka , Tanaka Kanta , Toyoda Kazunori , Yoshimura Sohei , Itabashi Ryo , Takagi Masahito , Todo Kenichi , Shiozawa Masayuki , Yagita Yoshiki , Yoshimoto Takeshi , Terasaki Tadashi , Yamagami Hiroshi , Takizawa Shunya , Inoue Manabu , Kamiyama Kenji , Ihara Masafumi , Okada Yasushi , Kitazono Takanari , Koga Masatoshi ,   on behalf of the SAMURAI Study Investigators
Published: January 2020

Background and Purpose—

We aimed to compare outcomes of ischemic stroke patients with nonvalvular atrial fibrillation between earlier and later initiation of direct oral anticoagulants (DOACs) after stroke onset.

Methods—

From data for 1192 nonvalvular atrial fibrillation patients with acute ischemic stroke or transient ischemic attack in a prospective, multicenter, observational study, patients who started DOACs during acute hospitalization were included and divided into 2 groups according to a median day of DOAC initiation after onset. Outcomes included stroke or systemic embolism, major bleeding, and death at 3 months, as well as those at 2 years.

Results—

DOACs were initiated during acute hospitalization in 499 patients in median 4 (interquartile range, 2–7) days after onset. Thus, 223 patients (median age, 74 [interquartile range, 68–81] years; 78 women) were assigned to the early group (≤3 days) and 276 patients (median age, 75 [interquartile range, 69–82] years; 101 women) to the late (≥4 days) group. The early group had lower baseline National Institutes of Health Stroke Scale score and smaller infarcts than the late group. The rate at which DOAC administration persisted at 2 years was 85.2% overall, excluding patients who died or were lost to follow-up. Multivariable Cox shared frailty models showed comparable hazards between the groups at 2 years for stroke or systemic embolism (hazard ratio, 0.86 [95% CI, 0.47–1.57]), major bleeding (hazard ratio, 1.39 [95% CI, 0.42–4.60]), and death (hazard ratio, 0.61 [95% CI, 0.28–1.33]). Outcome risks at 3 months also did not significantly differ between the groups.

Conclusions—

Risks for events including stroke or systemic embolism, major bleeding, and death were comparable whether DOACs were started within 3 days or from 4 days or more after the onset of nonvalvular atrial fibrillation–associated ischemic stroke or transient ischemic attack.

Registration—

URL:
https://www.clinicaltrials.gov
. Unique identifier: NCT01581502.
Peucedanum huangshanense (Apiaceae), a new species from Anhui, China

Authors: CHU SHAN-SHAN , WANG DE-QUN , PENG HUA-SHENG , HUANG LU-QI
Published: January 2020

Peucedanum huangshanense, a new species discovered in Anhui, China, is illustrated and described. Detailed morphological comparisons have showed that it is similar to P. praeruptorum but differs from the latter by having larger compound umbels (5–14 cm across), rays up to 25, and long-ovoid mericarps with lateral ribs narrowly winged. To explore the phylogenetic position of this species, nuclear ribosomal DNA internal transcribed spacer (ITS) region was sequenced for P. huangshanense and P. praeruptorum collected in different places. The morphological and molecular evidences support the hypothesis that P. huangshanense is a new distinct species.
A catalog of Rhagionidae (Diptera: Brachycera) from Chile
Authors: GONZÁLEZ CHRISTIAN R , ELGUETA MARIO , SANTOS CHARLES MORPHY D.
Published: January 2020

The genera and species of Chilean rhagionids (Diptera: Rhagionidae) are listed, with annotated references to nomenclature, synonymies and generic combinations, type localities, the primary type depositories, distribution, and citations for the most recent revisions. The genus Atherimorpha White is the richest genus in Chile, with 15 described species. Only Leptis basalis Philippi, 1865 is kept as incertae sedis in the family.
Strepsiptera from Colombia: First record of the genus Strichotrema Hofeneder (Myrmecolacidae) and a new host-parasitoid association with
Megalomyrmex cyendyra (Hymenoptera: Formicidae)
Authors: TOCORA MARÍA CAMILA , FIORENTINO GIANPIERO , FERNÁNDEZ FERNANDO
Published: January 2020

An overview of the order Strepsiptera in Colombia is provided. The family Halictophagidae is recorded for the first time based on a female parasitizing a treehopper Ceresini (Membracidae). Strichotrema beckeri is a new record for the country. The ant genus Megalomyrmex is documented as a new host for Caenocholax fenyesi. A short review of the ants parasitized by Strepsiptera in the Neotropics is presented. Currently, the order in Colombia is known for the families Halictophagidae, Myrmecolacidae and Stylopidae.
A Facile Chemical Solution Route to Synthesize ZnO/Graphene Composite and the Improved Photocatalytic Property
Authors: Hu Lingwei , Xing Xiuwei , Zhang Weina , Hu Chunhong , Li Jitao
Published: January 2020

ZnO/graphene composite was synthesized through a facile and economical chemical solution method at moderate temperature of 90 °C. The as-synthesized composite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD)
and Raman spectrum. Results indicated that in the growth process graphene oxide was reduced to graphene, in which ZnO was embedded in the form of nanoparticles. As an application, the photocatalytic performance of the composite was investigated using the methylene blue (MB) in aqueous solution
under ultraviolet (UV) light irradiation. The photocatalytic experiment showed that the as-synthesized ZnO/graphene composite exhibited improved photocatalytic property in comparison with that of the pure ZnO powder.
Characterization of Surface-Modified Halloysite Nanotubes by Thermal Treatment Under Reducing Atmosphere
Authors: Park Kihyun , Lee Jongseong , Chang Jeong Ho , Hwang Kyu Hong , Lee Younki
Published: January 2020

In recent years, the halloysite (Al2Si2O5(OH)4 · 2H2O) has been highlighted owing to its naturally occurring one-dimensionalmicrostructure that enables versatile applications. Due to the demand for enhancing surface interaction,
several types of research such as acid/base treatments have been conducted on the halloysite nanotubes. The objective of this study is to investigate the structural and surface properties of thermally treated halloysites under reducing atmosphere. The heat treatment is carried out in a gas-flow
furnace at 400–800 °C under various atmosphere, e.g., ambient air, 4% H2-balanced Ar, and 99.99% H2. The thermal treatment of halloysites under reducing atmosphere show a similar phase transition around 500 °C as the heating under air. However, the halloysite
reduced in pure hydrogen shows a significant increase of the zeta-potential, −36.7 mV for a 600 °C-treated sample, compared to the other samples. The mechanisms of the zeta-potential increase for the halloysite was also explored.
Development of Highly Expandable Wrinkled Nanofiber Mat Using Metal Bundle Collector
Authors: Lee Jun Hee , Yoon Deockhee , Park Jeesoo , Hwang Tae In , Park Chan Hee , Kim Cheol Sang
Published: January 2020

Nanofibers are used to improve performance in various fields such as biosensors and medical scaffolds. However, when it is used closely with a biological tissue, it is difficult to properly implement the original function due to the deformation caused by the constant movement of tissue.
In this study, we developed a wrinkled nanofiber mats with excellent expandability using a novel metal bundle collector. The wrinkled nanofiber mats are composed of aligned nanofiber and random nanofiber repeated at regular intervals, and can move appropriately in response to the strain as
the wrinkles formed in the aligned region can be wrinkled and spread.
Preparation of 1-D Nanostructured Tungsten Oxide Thin Film on Wire Mesh by Flame Vapor Deposition Process
Authors: Yoon Sang-Hyeok , Kim Kyo-Seon
Published: January 2020

Flame vapor deposition (FVD) process can be used to prepare the tungsten oxide thin film which has photocatalytic activity at visible light. The FVD process is fast and economical to prepare thin film on substrate comparing to other processes. Various nanostructured thin films could
be easily prepared by controlling several process parameters in FVD. One-dimensional (1-D) nanostructures with high surface area also can be prepared reproducibly. The tungsten wire precursor was oxidized and vaporized in flame to be deposited onto the substrate. The nanostructure shapes can
be adjusted by controlling nucleation and growth rates of tungsten oxide vapor on substrate. In this study, nanostructured tungsten oxide thin film was fabricated on stainless steel mesh by FVD process changing the process variables of FVD. We found that proper selection of suitable process
conditions in FVD was quite important for the 1-D nanostructure growth on stainless steel wire mesh with high surface area, which is quite important for photocatalytic application.
Fracture Surface of 3D Printed Honeycomb Structures at Low Temperature Environments
Authors: Choi Ju-Hwan , Leeghim Henzeh , Ahn Ju-Hun , Choi Dae-San , Lee Chang-Yull
Published: January 2020

In this paper, surface characteristics of 3D printed structures fractured at low temperature environments are analyzed. The samples are fabricated by using ABS (acrylonitrile butadiene styrene copolymer) material, and the structures are constructed by the well-known honeycomb models
using a FDM-Type 3D printer. To analyze the fracture surface of the samples constructed uniquely by using the 3D printer, the bending loads are applied to the samples at 30, −10 and −50 °C, respectively. The characteristics of the fracture surfaces of the 3D samples are also
observed by the FE-SEM (field emission scanning electron microscope) equipment. From this experiment, it is evaluated that the fractured surface of the 3D sample is very rough at 30 °C, while it is smooth at a relatively low temperature. Also, several unique features of the fracture surface
of a 3D printed sample structured by honeycomb models are also examined.
Synthesis of Ceramic/Polymer Nanocomposite Electrolytes for All-Solid-State Batteries
Authors: Lee Kyoung-Jin , Yi Eun-Jeong , Kim Gangsanin , Hwang Haejin
Published: January 2020

Lithium-ion conducting nanocomposite solid electrolytes were synthesized from polyethylene oxide (PEO), poly(methyl methacrylate) (PMMA), LiClO4, and Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramic particles. The synthesized nanocomposite electrolyte
consisted of LATP particles and an amorphous polymer. LATP particles were homogeneously distributed in the polymer matrix. The nanocomposite electrolytes were flexible and self-standing. The lithium-ion conductivity of the nanocomposite electrolyte was almost an order of magnitude higher than
that of the PEO/PMMA solid polymer electrolyte.
Effects of Seed Layer Coating and Oxygen Plasma Treatment on the Growth of ZnO Nanorods for UV Photodetector Applications
Authors: Kim Hyun-Jung , Chung Young-Hyuk , Hwang In-Tae , Jang Kyu-Won , Kim Hyun-Seok
Published: January 2020

Dark current in optical sensors has been one of their issues. The performance of these sensors can be improved by reducing their dark current. In this study, we investigated UV sensors based on ZnO nanorods (ZNRs), in particular, their current–voltage characteristics, response
and recovery times, on–off current ratio, and responsivity as a function of the device process conditions. The number of seed layer coatings was changed and an oxygen (O2) plasma treatment was applied to ZNRs. A microwave-assisted growth (MAG) method was used to grow ZNRs.
The MAG method is one way to shorten device manufacturing time. The small number of seed layer coating processes played a role in reducing the dark current of the sensor. The O2 plasma treatment further reduced the dark current. The crystal quality of ZNRs was affected by changes
in the sensor fabrication process. Although the O2 plasma treated device had an increased on–off current ratio, the response time was increased.
CO Sensing Properties of Chemiresistive In2O3/SnO2 Composite Nanoparticle Sensors
Authors: Nam Bumhee , Ko Tae-Kyung , Hyun Soong-Keun , Lee Chongmu
Published: January 2020

In2O3/SnO2 composite nanoparticles (NPs) were synthesized by a hydrothermal method. Fringes and spotty patterns were observed in high-resolution TEM images and corresponding selected area electron diffraction pattern, respectively, suggesting the nanoparticles
were single crystals. X-ray diffraction results revealed that the In2O3/SnO2 composite NP sensor consisted of three phases: In2O3, SnO2 and In2Sn2O7−x (indium tin oxide: ITO). Energy-dispersive
X-ray spectrum of the 9:1 In2O3/SnO2 composite NPs showed the atomic ratio of In2O3 to SnO2 was close to 9:1. The response of the chemiresistive sensor to CO was 9.2, which is within the highest 15% among the response values
reported for the past 10 years. The ITO NP-based gas sensor is selective toward CO against other reducing gases such as toluene, acetone and benzene. The enhanced response of the 9:1 In2O3/SnO2 composite NP sensor to CO compared to the pure In2O3
NP sensor can be explained mainly by the stronger resistance modulation at the In2O3/SnO2 junctions.
Boron Nitride as a Passivation Capping Layer for AlGaN/GaN High Electron Mobility Transistors
Authors: Lee Gun Hee , Park Ah Hyun , Lim Jin Hong , Lee Chil-Hyoung , Jeon Dae-Woo , Kim Young-Baek , Lee Jongho , Yang Jeon Wook , Suh Eun-Kyung , Seo Tae Hoon
Published: January 2020

We report on the electrical characteristics of AlGaN/GaN high-electron mobility transistors (HEMTs) with hexagonal boron nitride (h-BN) as a passivation capping layer. The HEMTs with h-BN layers showed an increase in current drainage and 103-times reduction in the gate-leakage current
compared with those of conventional unpassivated HEMTs. Moreover, the extrinsic transconductance and the pulse responses were improved due to the reduced charge-trapping effect at the surface of HEMTs. From our observations, the h-BN can be used as a passivation capping layer for high-power
electronic devices.
Resistance Characteristics and Particle Arrangement of Smart Paint for Surface Temperature Sensor
Authors: Ahn Ju-Hun , Leeghim Henzeh , Lee Chang-Yull
Published: January 2020

There are limitations on the shape of models that can be measured with commonly used temperature sensors. These disadvantages are difficult to measure temperatures of the curved surface. To overcome the shortcomings, a smart paint for temperature measurement is proposed in this work.
A polymer solution was prepared for viscosity of the paint and dispersion of materials. The BaTiO3 and Ag nanopaste are used for PTC characteristics and conductivity of the paint, respectively. Smart paint were analyzed the arrangement and shape of particles according to the processes
and production methods. Also, the change of resistance was measured while increasing the temperature. The results show that resistance increased as the temperature increased. The performance of the manufactured smart paint was confirmed as a surface temperature sensor.
Multi-Functional Cr–Al–Ti–Si–N Nanocomposite Films Deposited on WC-Co Substrate for Cutting Tools
Authors: Kim Wang Ryeol , Heo Sungbo , Kim Jun-Ho , Park In-Wook , Chung Wonsub
Published: January 2020

Multi-functional quinary Cr–Al–Ti–Si–N thin films were deposited onto WC-Co substrates using a cathodic arc evaporation system. In this study, the influence of silicon contents on the microstructure, mechanical, tribological, and oxidation properties of Cr–Al–Ti–Si–N
thin films were systematically investigated and correlated for application of cutting tools. Based on results from various analyses, the Cr–Al–Ti–Si–N films showed excellent properties including mechanical, tribological, oxidation and adhesion values compared with those
of the Cr–Al–Ti–N film. The Cr–Al–Ti–Si–N films with a Si content of around 4.21 at.% exhibited the highest hardness of 45 GPa, very low friction coefficient of 0.38 at room temperature against an Inconel alloy ball and superior adhesion property (105
N). The Cr–Al–Ti–Si–N films also showed excellent oxidation resistance after annealing in the ambient air at 1000 °C. Therefore, the Cr–Al–Ti–Si(4.21 at.%)–N films could be help to improve the performance of machining and cutting tools with
application of the films.
Effect of Vanadium Addition on the High-Temperature Friction Behavior in Nanostructured Al–Cr–V–N Films Prepared by UBMS
Authors: Kim Hyundong , Heo Sungbo , Kim Wang Ryeol , Kim Jun-Ho , Park In-Wook , Kim Kwang Ho
Published: January 2020

In recent year, vanadium-doped tribological films have become available as possible candidates for self-lubrication at high temperatures. In this work, quaternary Al–Cr–V–N films were deposited onto silicon wafer and WC-Co substrates by an unbalanced magnetron sputtering
using high purity (99.99%) CrAl2 and V targets with argon-nitrogen reactive gases. EPMA results revealed that vanadium atoms can incorporated from 0 to 13 at.% into the films. The maximum hardness value was ~32 GPa at vanadium content of 7.1 at.% in the Al–Cr–V–N
films. The high-temperature tribometer was used to analysis the friction characteristics of the films with elevated temperature. As a result of the high temperature friction test after heating up to 700 °C, the average friction coefficient decreased from 0.62 to 0.35 with increasing of
vanadium contents in the Al–Cr–V–N films. It is concluded that the reduction of the friction coefficient is attributed to the formation of V2O5, which is a Magnéli phase that acts as a lubrication at high temperature.
Puffed Rice Inspired Porous Carbon Co-MOFs Derived Composite Electrode for Lithium Ion Batteries
Authors: Zheng Guoxu , Yin Jinghua , Chen Minghua , Tian Shiyi , Li Botao , Gao Qingming
Published: January 2020

Carbon matrix metal organic frameworks (MOFs) hybrid is often used as electrode materials for lithium ion batteries (LIBs). Herein, we report three dimensional (3D) puffed rice inspired porous carbon (3DPRC) supported Co-MOFs derived composite by facile method. Co/C nanoparticles are
uniformly dispersed on porous carbon sheets surface, forming unique 3D structures. As anode of LIBs, the prepared Co/C-3DPRC electrode shows excellent electrochemical properties when compared with the pristine Co/C electrode. With capacity of 430 mAh g−1 at 1C and 300 mAh
g−1 at 10C is obtained in the composite electrode, respectively. The excellent properties can attribute to the Co/C-3DPRC interconnected porous framework with a high electrical conductivity and large surface area. Our developed design strategies can be extended for fabrication
of other heteroatom doped carbon matrix hybrid for environmental energy fields.
Impact of Synthesis Technique on Lanthanum Doped Copper Oxide Nanocrystals, an Alternative Counter Electrode for Pt-Free Dye-Sensitized Solar Cells
Authors: Rodney John. D. , Deepapriya S. , Annie Vinosha P. , Cyril Robinson M. , Krishnan S. , Martin Britto Dhas S. A. , Jerome Das S.
Published: January 2020

The ascendancy of a counter electrode (C.E) in a dye-sensitized solar cell (DSSC) has an unrivaled impact on the performance of the dye-sensitized solar cell, where the Pt-based C.E has set up a phenomenal benchmark against its counterparts. Due to the high cost of such noble metals,
an operative and a much cost effective replacement were greatly in demand to gratify this need. To address this issue, monoclinic lanthanum doped copper oxide (CuO) nanoparticles were prepared by solution combustion and co-precipitation techniques respectively as they possess highly superior
optoelectronic, catalytic and charge transfer properties. The effect of incorporating lanthanum (La) ions and the variation of synthesis technique on their structural, optical, photo-thermal and morphological properties are empirically investigated by XRD, FTIR, TEM, UV-Vis, Raman and Photoacoustic
Spectroscopy (PAS). The X-ray diffraction pattern revealed the formation of La-doped CuO nanoparticles. The finger-print vibrational modes of the as-synthesized samples are confirmed by the FTIR spectra. The required optical properties of the as-synthesized nanocrystals were confirmed using
UV-Vis absorption spectra, from which the bandgap was determined by Kubelka-Munk plot. The Raman modes were determined using Raman spectra, further a multi-phonon band was revealed, which was formed due to the plasmon-phonon coupling. The photothermal phenomenon was revealed using the photoacoustic
spectra. The morphological investigation by TEM found the change in the morphology of the material as the synthesis route is varied. The power conversion efficiency results unveiled that the combustion-derived C.E posted a promising efficiency (η) of 0.20% and the co-precipitation
derived C.E posted an efficiency of 0.02%. Overall results suggest that the combustion derived La doped CuO nanostructures exhibited substantive properties with deeper implication and also stood out to be a viable, cost-effective and self-exemplifying replacement for Pt as C.E in DSSC’s.
Effects of Recess Depth Under the Gate Area on the Vth-Shift for Fabricating Normally-Off Field Effect Transistors on AlGaN/GaN Heterostructures
Authors: Kim Zin-Sig , Lee Hyung Seok , Bae Sung-Bum , Nam Eun Soo , Lim Jong-Won
Published: January 2020

Fabrication of normally-off field effect transistors (FETs) possessed uniform turn-on threshold voltage (Vth) is of special interests. In this work, they were fabricated using dry etching recess techniques under the gate region, with dry etching conditions of extremely
low rate. We report how the recess depth under the gate area induced the Vth shift of normally-off FETs on AlGaN/GaN heterostructure, which were fabricated with a 1.5 nm/min etching rate. Chlorine-based inductively coupled plasma (ICP) was applied to perform the etching process
for the AlGaN/GaN heterostructure. Devices were fabricated with different recess depths under the gate area, and examined to determine their performances, particularly the dependence of recess time and recess depth on Vth shift. The applied dry etching conditions resulted
in a low-damaged and not-rough morphology on the etched surfaces of AlGaN/GaN. Fine controlled and well defined recess depth of the AlGaN/GaN heterostructure under the gate region was achieved with no etch-stop layers. Conventional fabrication processes were applied with the dry etching conditions
of extremely low rate to fabricate normally-off MOSFETs of Al2O3/AlGaN/GaN. The achieved Vth of +5.64 V was high positive and the leakage current of off-state was measured as ~10−6 A/mm.
High-Sensitivity Hydrogen Sensor Based on AlGaN/GaN Heterojunction Field-Effect Transistor
Authors: Choi June-Heang , Vuong Tuan Anh , Kim Hyungtak , Cha Ho-Young
Published: January 2020

We have developed a Pd-functionalized hydrogen gas sensor based on a recessed AlGaN/GaN heterostructure field-effect transistor. The AlGaN barrier layer under the Pd catalyst was partially etched to enhance its sensitivity. Both low-power consumption and high sensitivity were achieved
by employing a recessed structure. Sensor characterization was carried out at the temperature range from room temperature to 250 °C, among which the best sensing characteristics were observed at 200 °C. A sensitivity of 380% with a response time of 0.25 s was achieved at a bias voltage
of 0.3 V at 200 °C under a hydrogen exposure concentration of 4%. The standby power consumption was only 2 μW for the sensing area of 100×28 μm2 due to the low standby current, which was caused by the recessed AlGaN barrier layer.
Notched Anchor Design for Low Voltage Operation of Nanoelectromechanical (NEM) Memory Switches
Authors: Kang Min-Hee , Jo Hyun-Chan , Choi Woo Young
Published: January 2020

Because nanoelectromechanical (NEM) memory switches generally have higher pull-in voltage (VPI) and lower reliability than CMOS devices, reducing VPI and maximum stress (σMAX) of NEM memory switches have been critical issues
for the implementation of monolithic-3D (M3D) CMOS-NEM hybrid reconfigurable logic (RL) circuits. In this paper, a novel notched anchor design is proposed to reduce the VPI and σMAX of NEM memory switches. Moreover, the novel design has an advantage
in terms of chip density over the conventional design under the same VPI condition. In the case of our proposed NEM memory switches, their anchors are placed in the vias of metal interconnection layers. Thus, even if notched patterns are formed on the anchors, it will be
helpful to effectively increase beam length, which eventually lowers VPI and σMAX. In this manuscript, the proposed notched anchor design has been confirmed by finite-element-method (FEM) simulation. According to the simulation results, the proposed
notched anchor design lowers VPI by ~23% and σMAX by ~24%.
Effect of Word-Line Bias on Linearity of Multi-Level Conductance Steps for Multi-Layer Neural Networks Based on NAND Flash Cells
Authors: Lee Sung-Tae , Lim Suhwan , Choi Nagyong , Bae Jong-Ho , Kwon Dongseok , Kim Hyeong-Su , Park Byung-Gook , Lee Jong-Ho
Published: January 2020

NAND flash memory which is mature technology has great advantage in high density and great storage capacity per chip because cells are connected in series between a bit-line and a source-line. Therefore, NAND flash cell can be used as a synaptic device which is very useful for a high-density
synaptic array. In this paper, the effect of the word-line bias on the linearity of multi-level conductance steps of the NAND flash cell is investigated. A 3-layer perceptron network (784×200×10) is trained by a suitable weight update method for NAND flash memory using MNIST data
set. The linearity of multi-level conductance steps is improved as the word line bias increases from Vth −0.5 to Vth +1 at a fixed bit-line bias of 0.2 V. As a result, the learning accuracy is improved as the word-line bias increases from Vth
−0.5 to Vth+1.
Wide Angle X-ray Scattering as a Technique of Choice to Probe Asphaltene Hierarchical Structures
Authors: Calandra Pietro , Liveri Vincenzo Turco , Caputo Paolino , Teltayev Bagdat , Rossi Cesare Oliviero
Published: January 2020

Bitumens are composite systems extensively used in road pavements. Due to their complex nature, a rational understanding of the relationships between composition, structure and performances of these materials is still far from being achieved, so research attempting to shed more light
in this field is required. Here, we exploit Wide Angle X-ray Scattering (WAXS) as a technique of choice to shed light on the bitumen structure at different length scales. Diagnostic fingerprints, characterizing the WAXS profile, are correlated to specific Bragg distances which can be reasonably
attributed to the molecular and supramolecular aggregation taking place at various levels of complexity leading to the formation of hierarchical structures. Due to the inherent instability of these materials some indications are given to obtain reliable structural data.
Carbon Nanotube-Based Stretchable Hybrid Material Film for Electronic Devices and Applications
Authors: Fazi Laura , Gattia Daniele Mirabile , Pavone Luigi , Prioriello Anna , Scacco Valerio , Morales Piero , Mastroiacovo Federica , Gaglione Anderson , Moyanova Slavianka , Senesi Roberto
Published: January 2020

To meet the increasing demand, for stretchable conductive materials in a wide range of applications, innovative conductors based on single wall carbon nanotubes (SWCNT) self-grafted on different polymer films, are assembled. Aiming at a simple technology for flexible and stretchable
electronic devices, and contrary to what commonly reported for carbon nanotubes (CNT), no chemical functionalization of SWCNT is necessary for stable grafting onto several polymeric surfaces. The novelty and functionality of our composite materials stand in the synergy among the intrinsic
biocompatibility of CNT, a fully inert material, their electrical conductivity, and the stretchable-viscoelastic properties of the polymer-nanotube bundles composites. Electrical characterization of both unstretched and strongly stretched planar film conductors is provided, demonstrating the
use of this new composite material for technological application. Also, an insight into the mechanisms of strong adhesion to the polymer is obtained by scanning electron microscopy (SEM) of the surface composite. As an example of technological application of such stretchable circuitry, the
electrical functionality of a carbon nanotube-based six-sensor (electrode) grid is used to record subdural electrocorticograms in freely-moving laboratory rats over approximately three months.