bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression inEscherichia Coli, Purification, and Functional Reconstitution of Human Steroid 5α-Reductases
Authors: Peng Hwei-Ming , Valentín-Goyco Juan , Im Sang-Choul , Han Bing , Liu Jiayan , Qiao Jie , Auchus Richard J
Published: July 2020

The potent androgen 5α-dihydrotestosterone irreversibly derives from testosterone via the activity of steroid 5α-reductases (5αRs). The major 5αR isoforms in most species, 5αR1 and 5αR2, have not been purified to homogeneity. We report here the heterologous expression of polyhistidine-tagged, codon-optimized human 5αR1 and 5αR2 cDNAs in Escherichia coli. A combination of the nonionic detergents Triton X-100 and Nonidet P-40 enabled solubilization of these extremely hydrophobic integral membrane proteins and facilitated purification with affinity and cation-exchange chromatography methods. For functional reconstitution, we incorporated the purified isoenzymes into Triton X-100-saturated dioleoylphosphatidylcholine liposomes and removed excess detergent with polystyrene beads. Kinetic studies indicated that the 2 isozymes differ in biochemical properties, with 5αR2 having a lower apparent Km for testosterone, androstenedione, progesterone, and 17-hydroxyprogesterone than 5αR1; however, 5αR1 had a greater capacity for steroid conversion, as reflected by a higher Vmax than 5αR2. Both enzymes preferred progesterone as substrate over other steroids, and the catalytic efficiency of purified reconstituted 5αR2 exhibited a sharp pH optimum at pH 5. Intriguingly, we found that the prostate-cancer drug-metabolite 3-keto-∆ 4-abiraterone is metabolized by 5αR1 but not 5αR2, which may serve as a structural basis for isoform selectivity and inhibitor design. The functional characterization results with the purified reconstituted isoenzymes paralleled trends obtained with HEK-293 cell lines stably expressing native 5αR1 and 5αR2. Access to purified human 5αR1 and 5αR2 will advance studies of these important enzymes and might help to clarify their contributions to steroid anabolism and catabolism.
Caudal and Intravenous Anesthesia Without Airway Instrumentation for Laparoscopic Inguinal Hernia Repair in Infants: A Case Series
Authors: Krishnan Prakash , Whyte Simon D. , Baird Robert , Malherbe Stephan
Published: July 2020

We report a series of 20 neonates and infants (18 born preterm) who underwent laparoscopic inguinal hernia repair with caudal anesthesia, oxygen via nasal cannula, and intravenous anesthesia. Surgery was successful in all cases without airway instrumentation or intraoperative complications. Sedation was provided with dexmedetomidine, propofol, and remifentanil. Two patients had apnea in the following 24 hours. There were no unplanned intensive care admissions. Laparoscopy allowed unplanned bilateral repair in 2 cases. Caudal with intravenous anesthesia without airway instrumentation is a viable technique for laparoscopic inguinal hernia repair. Avoiding general endotracheal anesthesia may reduce perioperative complications and influence postoperative disposition.
Facial and Oral Cross-Contamination of a 3-Year-Old Child With High Concentration Capsaicin: A Case Report
Authors: Lassen Christoph L. , Meyer Kai , Bredthauer Andre , Klier Tobias W.
Published: July 2020

High-concentration topical capsaicin is used to treat different neuropathic pain states. We present a case in which a 3-year-old child orally ingested capsaicin after touching her mother’s arm that had been treated with a high-concentration capsaicin patch 3 hours earlier. The child suffered extreme pain and swelling of the lips and tongue. After the use of cleansing gel, external cooling, and drinking milk, the pain lessened over half an hour and subsided after 2 hours. This report aims to raise awareness for this formerly unreported mode of oral contamination.
Caenorhabditis elegans Flamingo FMI-1 controls dendrite self-avoidance through F-actin assembly
Authors: Hsu Hao-Wei , Liao Chien-Po , Chiang Yueh-Chen , Syu Ru-Ting , Pan Chun-Liang
Published: July 2020

Self-avoidance is a conserved mechanism that prevents crossover between sister dendrites from the same neuron, ensuring proper functioning of the neuronal circuits. Several adhesion molecules are known to be important for dendrite self-avoidance, but the underlying molecular mechanisms are incompletely defined. Here, we show that FMI-1/Flamingo, an atypical cadherin, is required autonomously for self-avoidance in the multidendritic PVD neuron of Caenorhabditis elegans. The fmi-1 mutant shows increased crossover between sister PVD dendrites. Our genetic analysis suggests that FMI-1 promotes transient F-actin assembly at the tips of contacting sister dendrites to facilitate their efficient retraction during self-avoidance events, probably by interacting with WSP-1/N-WASP. Mutations of vang-1, which encodes the planar cell polarity protein Vangl2 previously shown to inhibit F-actin assembly, suppress self-avoidance defects of the fmi-1 mutant. FMI-1 downregulates VANG-1 levels probably through forming protein complexes. Our study identifies molecular links between Flamingo and the F-actin cytoskeleton that facilitate efficient dendrite self-avoidance.
Cell type- and stage-specific expression of Otx2 is regulated by multiple transcription factors and cis-regulatory modules in the retina
Authors: Chan Candace S. Y. , Lonfat Nicolas , Zhao Rong , Davis Alexander E. , Li Liang , Wu Man-Ru , Lin Cheng-Hui , Ji Zhe , Cepko Constance L. , Wang Sui
Published: July 2020

Transcription factors (TFs) are often used repeatedly during development and homeostasis to control distinct processes in the same and/or different cellular contexts. Considering the limited number of TFs in the genome and the tremendous number of events that need to be regulated, re-use of TFs is necessary. We analyzed how the expression of the homeobox TF, orthodenticle homeobox 2 (Otx2), is regulated in a cell type- and stage-specific manner during development in the mouse retina. We identified seven Otx2 cis-regulatory modules (CRMs), among which the O5, O7 and O9 CRMs mark three distinct cellular contexts of Otx2 expression. We discovered that Otx2, Crx and Sox2, which are well-known TFs regulating retinal development, bind to and activate the O5, O7 or O9 CRMs, respectively. The chromatin status of these three CRMs was found to be distinct in vivo in different retinal cell types and at different stages. We conclude that retinal cells use a cohort of TFs with different expression patterns and multiple CRMs with different chromatin configurations to regulate the expression of Otx2 precisely.
Electrocommunication in pulse Gymnotiformes: the role of EOD time course in species identification.
Authors: Waddell Joseph C. , Caputi Angel A.
Published: July 2020

Understanding how individuals detect and recognize signals emitted by conspecifics is fundamental to discussions of animal communication. The species pair Gymnotus omarorum and Brachyhypopomus gauderio, found in syntopy in Uruguay, emit species-specific electric organ discharges that can be sensed by both species. The aim of this study was to unveil whether either of these species are able to identify a conspecific electric organ discharge, and to investigate distinctive recognition signal features. We designed a forced-choice experiment using a natural behavior (i.e. tracking electric field lines towards their source) in which each fish had to choose between a conspecific and a heterospecific electric field. We found a clear pattern of preference for a conspecific waveform even when pulses were played within 1 Hz of the same rate. By manipulating the time course of the explored signals, we found that the signal features for preference between conspecific and heterospecific waveforms were embedded in the time course of the signals. This study provides evidence that pulse Gymnotiformes can recognize a conspecific exclusively through species-specific electrosensory signals. It also suggests that the key signal features for species differentiation are probably encoded by burst coder electroreceptors. Given these results, and because receptors are sharply tuned to amplitude spectra and also tuned to phase spectra, we extend the electric color hypothesis used in evaluation of objects to apply to communication signals.
Reductive Functionalization of Carboxamides: A Recent Update
Authors: Ong Derek Yiren , Chen Jia-hua , Chiba Shunsuke
Published: July 2020

Carboxamides including lactams are readily available and bench-stable chemical feedstock, and thus their use in chemical synthesis for production of valuable compounds would be an attractive choice in various synthetic endeavors. This review highlights and discusses recent advances on deoxygenative reductive functionalization of carboxamides for the synthesis of α-branched amines, that is initiated by controlled single hydride delivery to the amide carbonyl group and terminated by downstream functionalization of the iminium intermediates. The protocols are categorized based on the types of the reduction processes including those with aluminum hydrides, the Schwartz's reagent, transition metal-catalyzed/mediated hydrosilylation, and sodium hydride-iodide composite.
Origin, conservation, and loss of alternative splicing events that diversify the proteome in Saccharomycotina budding yeasts
Authors: Hurtig Jennifer E. , Kim Minseon , Orlando-Coronel Luisa J. , Ewan Jellisa , Foreman Michelle , Notice Lee-Ann , Steiger Michelle A. , van Hoof Ambro
Published: July 2020

Many eukaryotes use RNA processing, including alternative splicing, to express multiple gene products from the same gene. The budding yeast Saccharomyces cerevisiae has been successfully used to study the mechanism of splicing and the splicing machinery, but alternative splicing in yeast is relatively rare and has not been extensively studied. Alternative splicing of SKI7/HBS1 is widely conserved, but yeast and a few other eukaryotes have replaced this one alternatively spliced gene with a pair of duplicated, unspliced genes as part of a whole genome doubling (WGD). We show that other examples of alternative splicing known to have functional consequences are widely conserved within Saccharomycotina. A common mechanism by which alternative splicing has disappeared is by replacement of an alternatively spliced gene with duplicate unspliced genes. This loss of alternative splicing does not always take place soon after duplication, but can take place after sufficient time has elapsed for speciation. Saccharomycetaceae that diverged before WGD use alternative splicing more frequently than S. cerevisiae, suggesting that WGD is a major reason for infrequent alternative splicing in yeast. We anticipate that WGDs in other lineages may have had the same effect. Having observed that two functionally distinct splice-isoforms are often replaced by duplicated genes allowed us to reverse the reasoning. We thereby identify several splice isoforms that are likely to produce two functionally distinct proteins because we find them replaced by duplicated genes in related species. We also identify some alternative splicing events that are not conserved in closely related species and unlikely to produce functionally distinct proteins.
Coisa de índio: Educação Escolar Indígena no Catu dos Eleotérios-RN
Authors: Costa Guilherme Luiz Pereira , Silva José Alberto da , Costa Ana Maria Morais
Published: July 2020

Trata-se de uma reflexão sobre conquistas do movimento indígena no Estado do Rio Grande do Norte na busca de uma educação e pelo direito de existir. Pretende-se refletir acerca de uma educação mediada como mecanismo de resistência. Para isso, os dados obtidos foram sistematizados a partir de estudos sobre a relação do Movimento Indígena Brasileiro com a educação diferenciada. No mais, utilizamos relatório de aula de campo à comunidade do Catu dos Eleotérios, a primeira comunidade indígena do referido estado a concretizar uma educação escolar indígena. Aqui, a escola indígena apresenta-se, portanto, como instrumento para a superação da invisibilidade, historicamente construída em diversos processos cumulativos de produção da inferioridade de populações indígenas.
Avaliação da capacidade carcinogênica do extrato aquoso de café, em células somáticas de Drosophila melanogaster
Authors: Oliveira Larissa Sousa , Vieira Thays Cunha , Morais Cássio Resende
Published: July 2020

Objetivo: devido ao consumo rotineiro do café pela população brasileira, o presente trabalho tem como objetivo avaliar o potencial carcinogênico de diferentes concentrações do café (Coffea arabica), por meio do Teste para Detecção de Tumor Epitelial em Drosophila melanogaster. Métodos: para avaliar o efeito carcinogênico do café, larvas de 3° estágio descendentes do cruzamento entre fêmeas virgens wts/TM3, sb¹ e machos mwh/mwh foram tratadas com diferentes concentrações de café comercial (100; 50; 25; 12,5 e 6,26 mg/mL). Após a exposição (48h) e o processo de metamorfose, as moscas adultas foram analisadas quanto à presença de tumor epitelial, e os grupos tratados foram comparados com o controle negativo (água ultrapura). A toxicidade do café foi mensurada por meio da taxa de moscas que sobreviveram a etapa de metamorfose após exposição. Resultados: foi observado diferença estatisticamente significativa na taxa de sobrevivência (p < 0,05) e na frequência de tumor epitelial total (p < 0,05) em moscas tratadas com 100 mg/mL de café, quando comparado ao controle negativo. Conclusões: o café, na concentração de 100 mg/mL, foi tóxico e carcinogênico para D. melanogaster.
Gestão de leitos em um hospital polo da região ampliada de saúde Jequitinhonha: aspectos organizacionais e operacionais do processo de trabalho
Authors: Souza Danielle Mandacaru , Vasconcelos Bruna Fonseca , Viana Danuza Maria Silva , Ribeiro Liliane da Consolação Campos , Lima Antônio Moacir de Jesus
Published: July 2020

Objetivo: descrever os aspectos organizacionais e operacionais do processo de trabalho da gestão de leitos de um hospital polo da Região Ampliada de Saúde Jequitinhonha Métodos: trata-se de um estudo de abordagem qualitativa por meio de entrevista semiestruturada gravada, realizada com 90 funcionários. Os dados foram categorizados e discutidos conforme análise de conteúdo. Resultados: emergiram seis categorias, sendo elas: organização dos processos de entrada e saída dos pacientes, comunicação, direcionamento dos pacientes para a clínica certa; hotelaria hospitalar; organização do serviço hospitalar e organização das cirurgias eletivas. Conclusões: este estudo evidenciou que, no hospital pesquisado, a gestão de leitos proporcionou melhoria nos aspectos organizacionais e operacionais do processo de trabalho, aumentou a rotatividade, a ocupação e diminuiu as taxas de permanência dos leitos, melhorou a comunicação entre os profissionais e garantiu uma melhor assistência aos pacientes internados, sem o aumento do número de leitos hospitalares.
Prevalência de coprescrição clinicamente significativa de psicofármacos inibidores da enzima CYP2D6 em usuários de um centro de atenção psicossocial
Authors: Silva Andreza Gomes da , Fernandes Maurício Avelar , Belfort Ilka Kassandra Pereira , Borges Mirlley Cristina Ferreira , Marinho Suanne Ferreira , Monteiro Sally Cristina Moutinho
Published: July 2020

Objetivo: mensurar a prevalência da coprescrição de psicofármacos inibidores clinicamente significativos da enzima CYP2D6. Métodos: estudo transversal realizado com usuários do Centro de Atenção Psicossocial de um município da Amazônia Legal. Os dados foram coletados de prontuário (medicamentos e diagnóstico clínico) e questionário semiestruturado (sociodemográficos). As informações referentes às medicações (substrato/inibidor da CYP2D6) foram consultadas no Micromedex®, Drug Interaction Checker, Food and Drug Administration e The Pharmacogene Variation Consortium. Os dados foram interpretados utilizando estatística descritiva percentual simples, considerando a média e o desvio-padrão. Para a confecção do banco de dados, utilizou-se o Office Excel®2010. Estudo aprovado pelo Comitê de Ética em Pesquisa sob o Parecer nº 289.937. Resultados: participaram deste estudo 43 pessoas com média de idade de 40,98 (±11,04) anos, sendo 55,81% do sexo masculino, 81,39% solteiros, 88,37% não brancos (pretos/pardos), 58,14% estudaram até o ensino médio e 62,79% tiveram diagnóstico F20 (esquizofrenia e subdivisões). Entre a população estudada, 100% (43/43) faziam uso diário de haloperidol, e 95,34% (41/43) encontravam-se em uso rotineiro de mais de uma droga metabolizada pela enzima CYP2D6. Verificou-se que 93% (40/43) dos participantes continham coprescrição de substratos e inibidores da enzima CYP2D6, sendo a maior prevalência de prescrições envolvendo ácido valproico, clorpromazina, levomepromazina, prometazina e risperidona. Conclusão: o estudo pôde mensurar alta prevalência de coprescrição de psicofármacos inibidores clinicamente significativos da enzima CYP2D6.
Management of competitiveness of products
Authors: Tyulin Andrey , Chursin Aleksandr
Published: July 2020

The textbook contains the basics of the theory and practice of management by competitiveness of products in the current market conditions. It describes new approaches to management of competitiveness of production taking into account features of knowledge-based industries — the main driving forces of the Russian economy. Considers the practical issues of managing competitiveness in order to enhance the competitiveness of the organization in terms of digitalization of the economy.
Meets the requirements of Federal state educational standards of higher education of the last generation.
For students of educational institutions of higher education studying in areas of training 38.04.02 "Management" (master level) and 38.04.01 "Economy" (master level), as well as graduate students and University professors engaged in training in these areas. Can be recommended to managers and specialists of companies, involved in the process of management competitiveness of the organization products.
Stabilizing Weighted Graphs
Authors: Koh Zhuan Khye , Sanità Laura
Published: July 2020

An edge-weighted graph [Formula: see text] is called stable if the value of a maximum-weight matching equals the value of a maximum-weight fractional matching. Stable graphs play an important role in network bargaining games and cooperative matching games, because they characterize instances that admit stable outcomes. We give the first polynomial-time algorithm to find a minimum cardinality subset of vertices whose removal from G yields a stable graph, for any weighted graph G. The algorithm is combinatorial and exploits new structural properties of basic fractional matchings, which are of independent interest. In contrast, we show that the problem of finding a minimum cardinality subset of edges whose removal from a weighted graph G yields a stable graph, does not admit any constant-factor approximation algorithm, unless P = NP. In this setting, we develop an O(Δ)-approximation algorithm for the problem, where Δ is the maximum degree of a node in G.
The psychological impact of returning to work
Authors: McNee Damien
Published: July 2020

Dentist Damien McNee considers the effects of COVID-19 as dentistry opens up to a new normal
Postcards from the chairside
Authors: Bates Natalie
Published: July 2020

Natalie Bates worked in the travel industry for six years. Now, she is sharing her journey from trainee to qualified dental nurse on Instagram. Here, she reveals why she changed her career destination
The reward of my maternity leave
Authors: Birkett Leanne
Published: July 2020

Dental nurse Leanne Birkett reveals how she blossomed as an oral health educator while off work to have her baby
Saving lives
Authors: Jevon Phil
Published: July 2020

Phil Jevon considers the safe use of oxygen in the dental practice

Aim

The aim of this article is to understand the safe use of oxygen in the dental practice.

Objectives

To discuss the recent MHRA alert about the incorrect use of portable oxygen cylinders To describe the routine checking and maintenance of oxygen cylinders To outline the procedure for ensure oxygen flow from a cylinder GDC development outcome C
Royal recognition for dental nurse support
Authors: Edgar Laura
Published: July 2020

Laura Edgar shares her top tips on keeping dental practices safe for patients and staff when they reopen
Developmental dysplasia of the hip
Authors: Zhang Stella , Doudoulakis Konstantinos J , Khurwal Anita , Sarraf Khaled M
Published: July 2020

Developmental dysplasia of the hip encompasses a range of hip abnormalities in which the femoral head and acetabulum fail to develop and articulate anatomically. Developmental dysplasia of the hip is a clinically important condition, with a prevalence of 1–2/1000 in unscreened populations and 5–30/1000 in clinically screened populations. The pathology is incongruence between the femoral head and the acetabulum, which can be caused by an abnormally shaped femoral head, acetabulum, or both. This results in a spectrum of different hip abnormalities.

The precise aetiology behind developmental dysplasia of the hip is unclear, but there are a number of established risk factors. In the UK, universal clinical examination of newborns and 6–8-week-old babies is performed under the national UK newborn screening programme for developmental dysplasia of the hip (part of the Newborn and Infant Physical Examination). The physical examination of the newborn hip involves initial inspection of the infant for any of the clinical features of developmental dysplasia of the hip, followed by hip stability tests (Barlow's and Ortolani's tests). Hip ultrasound is the gold standard diagnostic and monitoring tool for developmental dysplasia of the hip in newborns and infants under 6 months of age, or until ossification of the femoral head.

Some mild cases of developmental dysplasia of the hip (and the immature hip) resolve without requiring intervention; however, there are a number of treatments, both non-operative and operative, that may be used at various stages of this condition.
Business families in Southern Patagonia: from the end of the 19th Century to the first decades of 20th century
Authors: Bandieri Susana , Almaraz Araceli
Published: July 2020

The groups of settlers who arrived in Punta Arenas in Southern Patagonia in the second half of the 19th century, established the trade in hunting products, leather and exotic feathers. They organized the first companies as trading houses between individuals and friends. The capital accumulation of these immigrants promoted take-off and productive control based on external trade routes, an evidence of prior connections abroad. From 1881, the multiplication of some family companies boosted out controlling branches and suppliers of value productive chains through different association to foreign groups encouraged by the offer of land concessions. Partnership by friendship and family also added anonymous societies with a shareholder scheme including family members. The major article’s goal is to analyze first family business in this context, through a genealogy business approach. Theoretical concepts and method used here include debates of economic history and entrepreneurial history focused on family business. The core is social and commercial structures for understanding the family continuity, and also business survival in specific contexts. We elaborate three intertwined commercial and family genealogies that worked first in Punta Arenas before 1908 and later in Argentina. And, we analyze strategies by family members of second and third generations achieved for survival, and configuration of the Braun-Menéndez Behety business family. We relate some findings to the connections between Punta Arenas economy and European capitalism; interregional connections; the family as a socio-cultural dimension in entrepreneurship; management innovations in rural contexts and the pathways followed to establish the firsts mother-firms in Austral Patagonian Area.
The internationalisation of family SMEs in the Valencian region: the growing role played by Latin America, 1980-2018
Authors: Vidal Olivares Javier , Saiz Candelaria , Torró Lluís , Zabalza Juan
Published: July 2020

SME's and family businesses are central elements in Spain's modern economic growth. However, their process of internationalization has been little explored in recent research, particularly when it has been primarily aimed at emerging economies.  The article aims to understand and explain the internationalisation process of SME's in the Valencian region in Latin America. Through a set of cases of companies from different sectors (Metal, Machinery, Chemical, Ceramics, Textile, Furniture) it is showed that since 1990, the different Latin American countries have been increasing their presence in the preferential markets of most of the 22 companies studied. The growing role of the region in the investments of Valencian SME's shows the diversification and expansion of destination markets, including geographically not only the traditional European or Arab countries but also those of Latin America. Different reasons underlie this internationalisation: but the enterprises analysed based on a case studies approach showed different models of expansion. The common denominator being that of strategies specifically developed and adapted to the destination country's local environment: from an incremental and gradual expansion.
Pathways from Deglobalisation: Colombian Business Groups, 1950-1985
Authors: Rodriguez-Satizabal Beatriz Elena
Published: July 2020

What are the characteristics of the Colombian business groups and how did they evolve between 1950 and 1985? How did the characteristics change during a period of deglobalisation? This paper provides a description of the Colombian business groups. It tracks the evolution of 25 groups since their consolidation in the 1950s, during a period of Industrialization by Substitution of Imports (ISI), until 1985, a year before the Colombian government considered for the first time trade liberalisation policies. By concentrating on descriptive variables such as size, ownership and control, foundation year, and diversification, this paper provides an overview of the consolidation, development and restructuring of the groups. The task implied answering the underlying questions of what and who the business groups are by relying extensively on secondary literature for the main concepts and primary sources, valued for their ‘first-handedness’, to illustrate and complement the arguments on their characteristics. Combining the analysis of the track record of 25 groups, this research places the business group as the unit of analysis, and also includes 428 group-affiliated firms. Despite their current importance and presence in the economy since the second half of the twentieth century, a profile of the largest Colombian business groups during this period has not yet been produced. Most of the variables used to characterise the groups are the ones set out by the literature, however, the paper also brings indexes to quantify the historical evolution of the characteristics.
Political risk management practices of Multinational Corporations: their approaches to deal with developing countries under economic sanctions
Authors: Gonzalez-Bravo Yoel Modesto
Published: July 2020

This article explores adjustments to the traditional political risk management practices followed by Multinational Corporations (MNCs) in their international operations to incorporate an increasingly concerning risk arising from the more frequent imposition of economic sanctions on developing countries over the last ten years for political purposes. In order to identify the main determinants of this risk and its consequences, a literature review is conducted, highlighting the models proposed by Tsebelis (1990) and Kakutami (2017) as the main frameworks to understand the dynamics for sanctions impositions, their frequency and the management of this risk by traditional MNCs from developed countries. Kakutami’s model is further enhanced in this article with a game theoretical model to understand the dynamic behavior of MNCs under this context, considering evidences of a growing presence in international markets of MNCs from developing countries, whose motivations for their expansion are explored. Finally, different political risk mitigating strategies are reviewed to explore their suitability to MNCs, with particular emphasis on the use of insurance to cover this risk and its effects on MNCs’ willingness to engage with sanctioned countries. As a general finding, from a reputational point of view, MNCs should take a more active role in their network analysis to identify their direct and indirect exposure to this risk, given the more frequent imposition of sanctions with an extraterritorial reach.
Design of a free-form surface microlens array optical system with high efficiency and uniformity
Authors: Zhu Zhenmin , Yao Peiqi , Zheng Weihua
Published: July 2020

The microlens array has been widely applied in LED lighting source due to its special optical properties, but most of the research lacks the analysis and optimization of the complete mathematical models. Hence, the new design method of a free-form surface microlens array optical system is proposed in this paper. Based on the characteristics of TIR and the law of refraction, a complete mathematical model of the free-form microlens is established. By numerically solving a set of differential equations, the profile of the free-form surface microlens is obtained. Then we rotate the profile to get the free-form surface microlens. Finally, the proposed microlens array is simulated and analyzed in near-field and far-field situations, respectively. We also discuss the influence of microlens array characteristics on illumination performance. The result shows the uniformity and efficiency have been improved, both of which can reach more than 90%.
Multimodal affine registration for ICGA and MCSL fundus images of high myopia
Authors: Luo Gaohui , Chen Xinjian , Shi Fei , Peng Yunzhen , Xiang Dehui , Chen Qiuying , Xu Xun , Zhu Weifang , Fan Ying
Published: July 2020

The registration between indocyanine green angiography (ICGA) and
multi-color scanning laser (MCSL) imaging fundus images is vital for
the joint linear lesion segmentation in ICGA and MCSL and the
evaluation whether MCSL can replace ICGA as a non-invasive diagnosis
for linear lesion. To our best knowledge, there are no studies
focusing on the image registration between these two modalities. In
this paper, we propose a framework based on convolutional neural
networks for the multimodal affine registration between ICGA and MCSL
images, which contains two parts: coarse registration stage and fine
registration stage. In the coarse registration stage, the optic disc
is segmented and its centroid is used as a matching point to perform
coarse registration. The fine registration stage regresses affine
parameters directly using jointly supervised and weakly-supervised
loss function. Experimental results show the effectiveness of the
proposed method, which lays a sound foundation for further evaluation
of non-invasive diagnosis of linear lesion based on MCSL.
Numerical model of an Er3+/Yb3+ co-doped seven-core fiber amplifier for a space division multiplexing system
Authors: Nassiri Ali , Boulezhar Abdelkader , Idrissi Saba H.
Published: July 2020

Space division multiplexing (SDM) erbium-doped seven-core fiber amplifiers (EDFAs) are increasingly attracting interest due to their performances in improving capacity transmission systems. To increase the gain and improve the characteristics of the SDM seven-core fiber amplifier, this paper proposes the use of the erbium/ytterbium (

E
r

3
+

/

Y
b

3
+

) co-doped seven-core fiber amplifier. A theoretical model of the SDM co-doped seven-core fiber amplifier is developed. The presented results show that the proposed model allows us to obtain a peak gain over 60 dB at a wavelength of 1543 nm, a large bandwidth of 64 nm with a gain greater than 20 dB and with a minimum noise which is lower than 6 dB.
Propagation characteristics of Gaussian–Schell model beams through optical systems in Kerr media
Authors: Hu Jing , Wang Huan , Ji Xiaoling , Deng Yu , Chen Lifeng
Published: July 2020

For the beam spreading case, the propagation formulae of Gaussian–Schell model (GSM) beams through general optical systems in Kerr media are derived, and the propagation characteristics of GSM beams through an ideal thin lens in Kerr media are studied in detail. It is shown that the size and position of the beam waist can be controlled by the Kerr effect. Furthermore, the formula of the focal shift of the GSM beams focused by an ideal thin lens in Kerr media is also derived. It is found that in self-focusing media the focal shift decreases as the beam power or the beam coherence degree increases. In addition, there exists a maximum of the focal shift, and the formula of the focal shift maximum is derived. On the other hand, for the beam self-focusing case, the focusing characteristics of GSM beams focused by an ideal thin lens in Kerr media are also investigated.
Tunable radiative cooling based on a stretchable selective optical filter
Authors: Liu Xinhang , Pian Sijie , Zhou Rong , Shen Hao , Liu Xu , Yang Qing , Ma Yaoguang
Published: July 2020

Radiative cooling has the potential to drastically improve a wide range of energy conversion and utilization processes on Earth. However, the lack of tunability may limit its application in practical scenarios such as buildings, vehicles, and textiles. In this paper, we propose a new, to the best of our knowledge, approach to achieve tunable radiative cooling through a stretchable multilayer filter. The cooling power can be continuously modulated by mechanical stretching, which only requires a small amount of energy. This filter can be combined with existing static radiative cooling systems to achieve efficient and continuous regulation of cooling power.
Coupled-mode theory for microresonators with quadratic nonlinearity
Authors: Skryabin Dmitry V.
Published: July 2020

We use Maxwell’s equations to derive several models describing the interaction of the multi-mode fundamental field and its second harmonic in a ring microresonator with quadratic nonlinearity and quasi-phase-matching. We demonstrate how multi-mode three-wave mixing sums entering nonlinear polarization response can be calculated via Fourier transforms of products of the field envelopes. Quasi-phase-matching gratings with arbitrary profiles are incorporated seamlessly into our models. We also introduce several levels of approximations that allow us to account for dispersion of nonlinear coefficients and demonstrate how coupled-mode equations can be reduced to the envelope Lugiato–Lefever-like equations with self-steepening terms. An estimate for the

χ

(
2
)

induced cascaded Kerr nonlinearity, in the regime of imperfect phase-matching, puts it above the intrinsic Kerr effect by several orders of magnitude.
Generation and measurement of isolated attosecond pulses with enhanced flux using a two colour synthesized laser field
Authors: Greening D. , Weaver B. , Pettipher A. J. , Walke D. J. , Larsen E. W. , Marangos J. P. , Tisch J. W. G.
Published: July 2020

We have generated isolated attosecond pulses and performed attosecond streaking measurements using a two-colour synthesized laser field consisting of a strong near-infrared few-cycle pulse and a weaker multi-cycle pulse centred at 400 nm. An actively stabilized interferometer was used to coherently combine the two pulses. Using attosecond streaking we characterised the electric fields of the two pulses and accurately retrieved the spectrum of the multi-cycle pulse. We demonstrated a two-fold increase in the flux of isolated attosecond pulses produced and show that their duration was minimally affected by the presence of the weaker field due to spectral filtering by a multilayer mirror.
Dynamic characterization of polarization property in liquid-crystal-on-silicon spatial light modulator using dual-comb spectroscopic polarimetry
Authors: Koresawa Hidenori , Gouryeb Marc , Shibuya Kyuki , Mizuno Takahiko , Hase Eiji , Tokizane Yu , Oe Ryo , Minamikawa Takeo , Yasui Takeshi
Published: July 2020

Spectroscopic polarimetry (SP) is a powerful tool for characterization of thin film, polarization optics, semiconductor, and others. However, mechanical polarization modulation of broadband light hampers its application for dynamic monitoring of a sample. In this article, we demonstrate the dynamic SP with features of polarization-modulation-free polarimetry and spectrometer-free spectroscopy benefiting from dual-comb spectroscopy (DCS) using a pair of optical frequency combs (OFCs). DCS enables the direct determination of polarization without the need for polarization modulation by using mode-resolved OFC spectra of amplitude and phase for two orthogonally linear-polarized lights while securing rapid, high-precision, broadband spectroscopy without the need for spectrometer. Effectiveness of the proposed system is highlighted by visualizing the hysteresis property of dynamic response in a liquid-crystal-on-silicon spatial light modulator at a sampling rate of 105 Hz.
3D printed optical concentrators for LED arrays
Authors: Hamadani Behrang H. , Seppala Jonathan , Zarobila Clarence
Published: July 2020

Additive manufacturing methods based on photopolymerization offer a promising potential for fabrication of high quality, highly transparent optical components. One use of these technologies involves fabrication of parts for very specific and narrow applications. In this work, we first performed optical raytracing simulations to model an optimized freeform nonimaging concentrator for a custom-built 12-LED array and then fabricated several waveguide concentrators using 3D printing and characterized their optical characteristics. Our results demonstrate that realizing an irradiance of 17 kW/m2 or more with an irradiance nonuniformity of better than 2% over an area approaching 1 cm2 is realistic and that such an approach can rival intensities achieved with powerful lasers over a similar area. We also discuss an application where eight different types of LEDs were coupled into the waveguides to construct a solar simulator.
Versican and Versican-matrikines in Cancer Progression, Inflammation, and Immunity
Authors: Papadas Athanasios , Arauz Garrett , Cicala Alexander , Wiesner Joshua , Asimakopoulos Fotis
Published: July 2020

Versican is an extracellular matrix proteoglycan with key roles in multiple facets of cancer development, ranging from proliferative signaling, evasion of growth-suppressor pathways, regulation of cell death, promotion of neoangiogenesis, and tissue invasion and metastasis. Multiple lines of evidence implicate versican and its bioactive proteolytic fragments (matrikines) in the regulation of cancer inflammation and antitumor immune responses. The understanding of the dynamics of versican deposition/accumulation and its proteolytic turnover holds potential for the development of novel immune biomarkers as well as approaches to reset the immune thermostat of tumors, thus promoting efficacy of modern immunotherapies. This article summarizes work from several laboratories, including ours, on the role of this central matrix proteoglycan in tumor progression as well as tumor-immune cell cross-talk:
Biglycan in the Skeleton
Authors: Kram Vardit , Shainer Reut , Jani Priyam , Meester Josephina A.N. , Loeys Bart , Young Marian F.
Published: July 2020

Small leucine rich proteoglycans (SLRPs), including Biglycan, have key roles in many organ and tissue systems. The goal of this article is to review the function of Biglycan and other related SLRPs in mineralizing tissues of the skeleton. The review is divided into sections that include Biglycan’s role in structural biology, signaling, craniofacial and long bone homeostasis, remodeled skeletal tissues, and in human genetics. While many cell types in the skeleton are now known to be affected by Biglycan, there are still unanswered questions about its mechanism of action(s).
El teatro y la realidad virtual como metodología experimental en humanidades
Authors: Cebral Loureda Manuel
Published: July 2020

Si bien las denominadas Ciencias Exactas cuentan con un laboratorio extensamente contrastado durante siglos en donde se ponen a prueba, cuantitativamente, cualidades objetivas de diversos fenómenos del mundo, no pasa lo mismo con las Humanidades. El carácter relativo de su objeto -los sujetos humanos y sus formas de expresión artística y filosófica, principalmente- así como lo subjetivo de las facultades que ponen en juego -la sensibilidad, los afectos e, incluso, la conciencia histórica- hacen que el método del laboratorio científico moderno no sea suficiente en este área de investigación. Para dar respuesta a este problema, el teatro puede ser una metodología apropiada, tal como lo han propuesto, en los últimos años, filósofos como Gilles Deleuze o Graham Harman. Si bien hay ciertas desavenencias entre estos dos filósofos, el presente artículo pretende mostrar importantes rasgos comunes así como el modo en que ambas concepciones del teatro y la filosofía se pueden ver reforzadas por la aplicación de nuevas tecnologías -realidad virtual y/o aumentada- para dar lugar a laboratorios contemporáneos de Humanidades Digitales basados en la simulación, la inmersión y la interacción.
Estado del cultivo en el binomio ciudad-huerta de Valencia por medio de aplicaciones artísticas interactivas
Authors: Gutiérrez González María José
Published: July 2020

Durante siglos ha perdurado una estrecha relación de dependencia y prosperidad entre la ciudad y la huerta en Valencia. En la actualidad, la interacción en dicho binomio se ha ido debilitando progresivamente, ya que el elemento urbano se ha impuesto con sus ampliaciones descontroladas, sumado a un estilo de vida y una producción de riqueza desvinculados de la tierra y el cultivo. Este paisaje con una elevada carga cultural se encuentra en un estado crítico de conservación y todavía hoy no se vislumbra un claro porvenir. La producción artística, a través de aplicaciones interactivas se convierte en un mecanismo para combatir y visibilizar esta problemática. A través de la contraposición de datos del pasado sobre el paisaje que recorre el trayecto de la histórica acequia de la Rascanya. En consecuencia, utilizamos los escritos del botánico Antonio José Cavanilles que desarrolló a finales del siglo XVIII sobre la ciudad y sus alrededores, relatan la relación en equilibrio que permitía la convivencia y la riqueza en ambos espacios, además de un optimizado aprovechamiento de los recursos naturales.
¿Qué ocurre con la empleabilidad? Reflexiones críticas sobre su orientación y desafíos en tiempos de crisis
Authors: Santamaría López Elsa , Orteu Guiu Xavier
Published: July 2020

Una de las víctimas reiterativas de las crisis es el empleo en tanto marco para la inclusión social. Este artículo revisa las consecuencias que las políticas activas de empleo, bajo la lógica de la empleabilidad, tienen en las posibilidades de inclusión social en el mercado de trabajo. Se observa que la lógica de la empleabilidad, lejos de tener unos resultados claros en la mejora de la participación laboral, contribuye a las desigualdades y a las situaciones de desprotección y de precariedad laboral contemporáneas. Por lo tanto, se reflexiona en la búsqueda de otros enfoques de la empleabilidad que sitúen al trabajo como una forma de participación social y no únicamente como una modalidad de provisión de ingresos. Finalmente, se propone que las políticas activas de empleo necesitan hacer una revisión de su noción de empleabilidad, para que no se limite sólo a una cuestión de mejoría técnica en el acceso a un empleo, y pueda ser encauzada como una herramienta colectiva de recuperación del sentido de pertenencia y de utilidad social.
La realización de reconocimientos médicos para la detección de COVID-19 a los trabajadores
Authors: Marín Malo Mirentxu
Published: July 2020

El presente trabajo analiza la posibilidad de realizar pruebas de carácter obligatorio a los trabajadores para la detección de sintomatología compatible con la Covid-19. El objetivo perseguido con estas pruebas es el de proteger la seguridad y salud de los trabajadores, por una parte; y evitar la propagación del virus, por otra. Para lograr el objetivo perseguido con este trabajo, se analiza, por una parte, la regulación relativa a la realización de reconocimientos médicos en el medio laboral, tanto en su contenido como en sus límites, dirigidos de manera especial a proteger el derecho a la intimidad recogido en el art. 18 CE. Posteriormente, se estudia el contenido del Reglamento General de Protección de Datos, haciendo especial referencia a los principios reguladores del tratamiento y a como limitan el uso de medios de detección de SARS-CoV-2 en las empresas.
El empleo temporal en las administraciones públicas: límites, prevención y sanción a su utilización abusiva
Authors: Arrieta Idiakez Francisco Javier
Published: July 2020

El objetivo principal de este artículo es determinar si en España existen medidas para prevenir y, en su caso, sancionar el uso abusivo del empleo temporal en las Administraciones públicas. Para ello, en primer lugar, se analizarán las distintas modalidades de empleo temporal que existen en las Administraciones públicas, profundizando, en especial, en la figura del contrato indefinido no fijo, debido a las dudas que genera. En segundo lugar, se abordarán los límites al empleo temporal en las Administraciones públicas que se regulan tanto en la Directiva 1999/70 como en el Derecho interno. Finalmente, se centrará la atención en determinar si en España existen medidas adecuadas para prevenir y, en su caso, sancionar los abusos derivados de la utilización de sucesivos contratos de duración determinada. A tal efecto, se analizarán la normativa interna y la jurisprudencia del TJUE.
Reseña de Gutiérrez, D. Sócrates y la práctica de la espiritualidad (2019)
Authors: Iversen Francisco
Published: July 2020

Reseña de Gutiérrez, D. Sócrates y la práctica de la espiritualidad (2019).
A Teoria da Demonstração Científica de Aristóteles em Segundos Analíticos 1.2-9 e 1.13
Authors: Bastos Davi
Published: July 2020

Defendo uma interpretação do livro I dos Segundos Analíticos de Aristóteles que distingue dois projetos em diferentes trechos da obra: (i) explicar em que consiste uma dada ciência e (ii) explicar em que consiste o conhecimento propriamente científico. Exponho a teoria de Aristóteles que responde à questão ii, com especial atenção à definição de conhecimento científico em 71b9-12 e mostrando como isso se desdobra ao longo dos capítulos 1.2-9 e 1.13 em uma consistente Teoria da Demonstração Científica. O principal ponto dessa teoria é que demonstrações precisam capturar explicações relevantes. Alguns requisitos formais (como a estrutura silogística e a coextensão de termos) são desdobramentos do alvo principal, a saber, capturar e expor de forma apropriada relações causais-explanatórias relevantes.