bluuebunny/crossref_metadata_2025 huggingface dataset:
Epistatic Effect of Regulators to the Adaptive Growth of Escherichia coli
Authors: Miyake Yukari , Yamamoto Kaneyoshi
Published: February 2020

Bacteria survive in the environment with three steps: a sensing environmental conditions, a responding to sensed signals, and an adaptation for proper survival in the environment. An adapting bacterial cell occurs cell division to increase the number of sister cells, termed adaptive growth. Two-component systems (TCSs), representing the main bacterial signal transduction systems, consist of a pair of one sensor kinase (SK) and one response regulator (RR), and RR genes are abundant in most bacterial genomes as part of the core genome. The OmpR gene family, a group of RR genes, is conserved in 95% of known bacterial genomes. The Escherichia coli genome has an estimated 34 RR genes in total, including 14 genes of OmpR family genes. To reveal the contribution of TCSs for fast growth as an adaptive growth strategy of E. coli, we isolated a set of gene knockout strains by using newly developed genome editing technology, the HoSeI (Homologous Sequence Integration) method, based on CRISPR-Cas9. The statistics of single cell observation show a knockout of an arbitrary pair of phoP, phoB, and ompR genes, stably expressed by positive feedback regulation, dramatically inhibit the optimum adaptive growth of E. coli. These insights suggest that the adaptive growth of bacteria is fulfilled by the optimum high intracellular level of regulators acquired during growth under environmental conditions.
Reconstructing temporal and spatial dynamics from single-cell pseudotime using prior knowledge of real scale cell densities
Authors: Kuritz Karsten , Stöhr Daniela , Maichl Daniela Simone , Pollak Nadine , Rehm Markus , Allgöwer Frank
Published: February 2020

Modern cytometry methods allow collecting complex, multi-dimensional data sets from heterogeneous cell populations at single-cell resolution. While methods exist to describe the progression and order of cellular processes from snapshots of such populations, these descriptions are limited to arbitrary pseudotime scales. Here we describe MAPiT, an universal transformation method that recovers real-time dynamics of cellular processes from pseudotime scales by utilising knowledge of the distributions on the real scales. As use cases, we applied MAPiT to two prominent problems in the flow-cytometric analysis of heterogeneous cell populations: (1) recovering the kinetics of cell cycle progression in unsynchronised and thus unperturbed cell populations, and (2) recovering the spatial arrangement of cells within multi-cellular spheroids prior to spheroid dissociation for cytometric analysis. Since MAPiT provides a theoretic basis for the relation of pseudotime values to real temporal and spatial scales, it can be used broadly in the analysis of cellular processes with snapshot data from heterogeneous cell populations.
Author Correction: Controlling parameters and characteristics of electrochemical biosensors for enhanced detection of 8-hydroxy-2′-deoxyguanosine
Authors: Faria Aline M. , Peixoto Elisa B. M. I. , Adamo Cristina B. , Flacker Alexander , Longo Elson , Mazon Talita
Published: February 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Urethral Instillation of Povidone-Iodine Reduces Post-Cystoscopy Urinary Tract Infection in Males: A Randomized Controlled Trial
Authors: Nayyar Rishi , Dadhwal Rohit , Kapil Arti , Pandey Ravindra Mohan , Dogra PremNath
Published: February 2020

Office cystoscopy may be associated with urinary tract infection (UTI) in up to 10–20% of patients. Current practice of surgical part preparation in males with povidone-iodine excludes distal urethra in males, leaving a possibility for resident intra-urethral flora to cause post-procedural UTI. We designed this randomized study to assess whether additional cleaning of distal urethra with povidone-iodine solution can help reduce post-procedural incidence of UTIs in this setting. Additionally, urethral swab culture was done in the entire cohort to identify the prevalent microflora in the distal male urethra and to evaluate its role in causation of post-procedural UTI. Using a specialized urethral swab culture methodology, 85% males demonstrated some bacteria and 16% showed common uro-pathogens. 28 (14.5%) cases had post-procedure culture positive UTI. The incidence of UTI in control group (22%) was significantly more than the intervention group (7%) (p value <0.007). This result strongly supports inclusion of distal urethral irrigation with povidone-iodine in males before office cystoscopy, even when pre-procedure mid-stream urine culture is sterile.
Endothelin-1 Mediated Decrease in Mitochondrial Gene Expression and Bioenergetics Contribute to Neurodegeneration of Retinal Ganglion Cells
Authors: Chaphalkar Renuka M. , Stankowska Dorota L. , He Shaoqing , Kodati Bindu , Phillips Nicole , Prah Jude , Yang Shaohua , Krishnamoorthy Raghu R.
Published: February 2020

Endothelin-1 (ET-1) is a vasoactive peptide that is elevated in aqueous humor as well as circulation of primary open angle glaucoma (POAG) patients. ET-1 has been shown to promote degeneration of optic nerve axons and apoptosis of retinal ganglion cells (RGCs), however, the precise mechanisms are still largely unknown. In this study, RNA-seq analysis was used to assess changes in ET-1 mediated gene expression in primary RGCs, which revealed that 23 out of 156 differentially expressed genes (DEGs) had known or predicted mitochondrial function, of which oxidative phosphorylation emerged as the top-most enriched pathway. ET-1 treatment significantly decreased protein expression of key mitochondrial genes including cytochrome C oxidase copper chaperone (COX17) and ATP Synthase, H+ transporting, Mitochondrial Fo Complex (ATP5H) in primary RGCs and in vivo following intravitreal ET-1 injection in rats. A Seahorse ATP rate assay revealed a significant decrease in the rate of mitochondrial ATP production following ET-1 treatment. IOP elevation in Brown Norway rats showed a trend towards decreased expression of ATP5H. Our results demonstrate that ET-1 produced a decrease in expression of vital components of mitochondrial electron transport chain, which compromise bioenergetics and suggest a mechanism by which ET-1 promotes neurodegeneration of RGCs in glaucoma.
Pesticide pollution in freshwater paves the way for schistosomiasis transmission
Authors: Becker Jeremias M. , Ganatra Akbar A. , Kandie Faith , Mühlbauer Lina , Ahlheim Jörg , Brack Werner , Torto Baldwyn , Agola Eric L. , McOdimba Francis , Hollert Henner , Fillinger Ulrike , Liess Matthias
Published: February 2020

Schistosomiasis is a severe neglected tropical disease caused by trematodes and transmitted by freshwater snails. Snails are known to be highly tolerant to agricultural pesticides. However, little attention has been paid to the ecological consequences of pesticide pollution in areas endemic for schistosomiasis, where people live in close contact with non-sanitized freshwaters. In complementary laboratory and field studies on Kenyan inland areas along Lake Victoria, we show that pesticide pollution is a major driver in increasing the occurrence of host snails and thus the risk of schistosomiasis transmission. In the laboratory, snails showed higher insecticide tolerance to commonly found pesticides than associated invertebrates, in particular to the neonicotinoid Imidacloprid and the organophosphate Diazinon. In the field, we demonstrated at 48 sites that snails were present exclusively in habitats characterized by pesticide pollution and eutrophication. Our analysis revealed that insensitive snails dominated over their less tolerant competitors. The study shows for the first time that in the field, pesticide concentrations considered “safe” in environmental risk assessment have indirect effects on human health. Thus we conclude there is a need for rethinking the environmental risk of low pesticide concentrations and of integrating agricultural mitigation measures in the control of schistosomiasis.
Lossless immunocytochemistry using photo-polymerized hydrogel thin-films
Authors: Lee Jeong Hyun , Santoso Aline T. , Park Emily S. , Matthews Kerryn , Duffy Simon P. , Ma Hongshen
Published: February 2020

Encapsulating cell samples in porous hydrogel thin-films eliminates cell loss and reduces processing time in standard immunocytochemistry workflows.
π-Conjugated polymeric phthalocyanine for the oxidative coupling of amines
Authors: Wu Haihong , Cao Yanwei , Zhu Gangli , Zeng Dehong , Zhu Xiang , Du Jimin , He Lin
Published: February 2020

A cross-linked π-conjugated polymeric cobalt phthalocyanine material was prepared, showing high activity for the aerobic oxidative coupling of amines and recyclability.
Visualization of the slide-ring effect: a study on movable cross-linking points using mechanochromism
Authors: Lu Yi , Aoki Daisuke , Sawada Jun , Kosuge Takahiro , Sogawa Hiromitsu , Otsuka Hideyuki , Takata Toshikazu
Published: February 2020

To evaluate the ‘slide-ring’ effect in a rotaxane cross-linked network, we incorporated mechanochromophores into static and rotaxane cross-linking points and compared the mechanochromisms exhibited by the obtained polymers.
Hexanuclear [Cp*Dy]6 single-molecule magnet
Authors: Wu Jianfeng , Demeshko Serhiy , Dechert Sebastian , Meyer Franc
Published: February 2020

A hexanuclear cluster containing six {Cp*Dy} units shows a high energy barrier (Ueff= 561 K) for magnetic relaxation and butterfly-shaped hysteresis loops up to 4.5 K.
Novel insights into biomass delignification with acidic deep eutectic solvents: a mechanistic study of β-O-4 ether bond cleavage and the role of the halide counterion in the catalytic performance
Authors: da Costa Lopes André M. , Gomes José R. B. , Coutinho João A. P. , Silvestre Armando J. D.
Published: February 2020

The potentiality of acidic deep eutectic solvents for β-O-4 ether bond cleavage is herein demonstrated from a mechanistic point of view.
A dispersive solid phase extraction-based method for chromium(vi) analysis using a Zn–Al layered double hydroxide intercalated with l-aspartic acid as a dissolvable adsorbent
Authors: Leite Victor dos Santos Azevedo , Constantino Vera Regina Leopoldo , Izumi Celly Mieko Shinohara , Tronto Jairo , Pinto Frederico Garcia
Published: February 2020

An analytical method for extraction and preconcentration of Cr(vi) in water with DSPE using a Zn–Al LDH intercalated with l-aspartic acid as a dissolvable adsorbent.
Enantioconvergent alkylation of ketones with racemic secondary alcohols via hydrogen borrowing catalysis
Authors: Cheang Daniella M. J. , Armstrong Roly J. , Akhtar Wasim M. , Donohoe Timothy J.
Published: February 2020

An enantioconvergent hydrogen borrowing strategy enables the catalytic asymmetric alkylation of ketone enolates with unactivated, racemic secondary alcohols.
A hydrogen borrowing annulation strategy for the stereocontrolled synthesis of saturated aza-heterocycles
Authors: Chamberlain Anna E. R. , Paterson Kieran J. , Armstrong Roly J. , Twin Heather C. , Donohoe Timothy J.
Published: February 2020

A hydrogen borrowing annulation strategy enables the stereocontrolled synthesis of C2, C3 and C4-substituted saturated aza-heterocycles.
Stepwise approach for sterically hindered Csp3–Csp3 bond formation by dehydrogenative O-alkylation and Lewis acid-catalyzed [1,3]-rearrangement towards the arylalkylcyclopentane skeleton of sesquiterpenes
Authors: Fujitani Ban , Hanaya Kengo , Sugai Takeshi , Higashibayashi Shuhei
Published: February 2020

A stepwise dehydrogenative cross-coupling method was developed for the formation of sterically hindered Csp3–Csp3 bonds.
Temperature- and pressure-dependent kinetics of the competing C–O bond fission reactions of dimethoxymethane
Authors: Golka Leonie , Gratzfeld Dennis , Weber Isabelle , Olzmann Matthias
Published: February 2020

Under typical shock tube conditions, dimethoxymethane decomposes mainly to give CH3+ OCH2OCH3.
On the wetting translucency of hexagonal boron nitride
Authors: Wagemann Enrique , Wang Yanbin , Das Siddhartha , Mitra Sushanta K.
Published: February 2020

When a drop sits on an atomically thin coating supported by a hydrophilic material, it is possible that the underlying substrate influences the equilibrium contact angle. Such behavior is known as the wetting translucency effect.
A novel vapor generation method using hydrogen-containing plasma for Se direct solid sampling
Authors: Li Ming , Xing Zhi , Sun Gongwei , Liang Jing , Huang Xiu , Fan Bowen , Wang Qing
Published: February 2020

A new method for chemical vapor generation by hydrogen-containing plasma has been proposed for Se solid sampling.
The role of membrane-shaping BAR domain proteins in caveolar invagination: from mechanistic insights to pathophysiological consequences
Authors: Kessels Michael M. , Qualmann Britta
Published: February 2020

The formation of caveolae, bulb-shaped plasma membrane invaginations, requires the coordinated action of distinct lipid-interacting and -shaping proteins. The interdependence of caveolar structure and function has evoked substantial scientific interest given the association of human diseases with caveolar dysfunction. Model systems deficient of core components of caveolae, caveolins or cavins, did not allow for an explicit attribution of observed functional defects to the requirement of caveolar invagination as they lack both invaginated caveolae and caveolin proteins. Knockdown studies in cultured cells and recent knockout studies in mice identified an additional family of membrane-shaping proteins crucial for caveolar formation, syndapins (PACSINs) — BAR domain superfamily proteins characterized by crescent-shaped membrane binding interfaces recognizing and inducing distinct curved membrane topologies. Importantly, syndapin loss-of-function resulted exclusively in impairment of caveolar invagination without a reduction in caveolin or cavin at the plasma membrane, thereby allowing the specific role of the caveolar invagination to be unveiled. Muscle cells of syndapin III KO mice showed severe reductions of caveolae reminiscent of human caveolinopathies and were more vulnerable to membrane damage upon changes in membrane tensions. Consistent with the lack of syndapin III-dependent invaginated caveolae providing mechanoprotection by releasing membrane reservoirs through caveolar flattening, physical exercise of syndapin III KO mice resulted in pathological defects reminiscent of the clinical symptoms of human myopathies associated with caveolin 3 mutation suggesting that the ability of muscular caveolae to respond to mechanical forces is a key physiological process.
Interleukin-17A induces vascular remodeling of small arteries and blood pressure elevation
Authors: Orejudo Macarena , García-Redondo Ana B. , Rodrigues-Diez Raúl R. , Rodrigues-Díez Raquel , Santos-Sanchez Laura , Tejera-Muñoz Antonio , Egido Jesús , Selgas Rafael , Salaices Mercedes , Briones Ana M. , Ruiz-Ortega Marta
Published: February 2020

An important link exists between hypertension and inflammation. Hypertensive patients present elevated circulating levels of proinflammatory cytokines, including interleukin-17A (IL-17A). This cytokine participates in host defense, autoimmune and chronic inflammatory pathologies, and cardiovascular diseases, mainly through the regulation of proinflammatory factors. Emerging evidence also suggests that IL-17A could play a role in regulating blood pressure and end-organ damage. Here, our preclinical studies in a murine model of systemic IL-17A administration showed that increased levels of circulating IL-17A raised blood pressure induced inward remodeling of small mesenteric arteries (SMAs) and arterial stiffness. In IL-17A-infused mice, treatment with hydralazine and hydrochlorothiazide diminished blood pressure elevation, without modifying mechanical and structural properties of SMA, suggesting a direct vascular effect of IL-17A. The mechanisms of IL-17A seem to involve an induction of vascular smooth muscle cell (VSMC) hypertrophy and phenotype changes, in the absence of extracellular matrix (ECM) proteins accumulation. Accordingly, treatment with an IL-17A neutralizing antibody diminished SMA remodeling in a model of angiotensin II (Ang II) infusion. Moreover, in vitro studies in VSMCs reported here, provide further evidence of the direct effects of IL-17A on cell growth responses. Our experimental data suggest that IL-17A is a key mediator of vascular remodeling of the small arteries, which might contribute, at least in part, to blood pressure elevation.
New four‐dimensional signal constellations construction
Authors: Ugrelidze Nodar , Shavgulidze Sergo , Sordia Mariam
Published: February 2020

In this study, the authors present new four‐dimensional signal constellations constructed based on combinations of binary frequency shift keying and M‐ary phase‐shift keying. Such a system contains two sub‐constellations and phase shift keying modulation is carried out based on two different frequencies. They obtained an analytical expression for calculating of squared Euclidean distance for different signal constellations. The new method of system construction and optimisation is presented with the help of this formula. Having used this method for various signal constellations and modulation indexes, they constructed optimised systems. In tables, they present the parameters for signal constellation sizes 4, 5, …,16 and modulation indexes 0.1, 0.2, …,1. Such signal constellations can be used in MIMO systems and, in particular, in generalised multi‐stream spatial modulation systems.
Cluster splitting and combining in ultra‐dense networks
Authors: Park Jae‐Wan , Kim Eung‐Hyo , Hong Een‐Kee
Published: February 2020

The ultra‐dense network (UDN) has been identified as a promising solution to accommodate a tremendously increasing number of traffic. Clustering for small cell base stations is considered as an efficient frequency resource management scheme. In this study, the authors propose a flexible clustering algorithm to achieve traffic load balancing between clusters as well as reduced inter‐cell interference. They implement a malleable cluster configuration with cluster splitting and recombining. Simulation results demonstrate that the proposed clustering technique is useful and practical, providing high average throughput and lowering outage probability.
Non‐unit travelling wave protection method for dc transmission line using waveform correlation calculation
Authors: Zhang Chenhao , Song Guobing , Yang Liming , Dong Xinzhou
Published: February 2020

High voltage dc (HVDC) transmission, especially voltage source converter (VSC)‐based HVDC transmission requires high‐speed operation for relay protection. However, traditional derivative‐based non‐unit travelling wave‐based protection (TWP) methods are sensitive to the fault impedance, resulting in low protection sensitivity in case of the high‐impedance fault. First, the fault information containing in the fault travelling wavefront is analysed based on the frequency‐dependent parameters of the dc transmission line and the broadband characteristic of the fault‐point initial travelling wave. It can be concluded that the distortion of the fault travelling wavefront depends on the fault distance and the amplitude of the fault travelling wavefront depends on the fault impedance. Then, a principle of non‐unit TWP for dc transmission line based on waveform correlation calculation is proposed. The proposed method is verified in both thyristor‐based HVDC and VSC HVDC PSCAD test systems. The simulation results verify the high‐speed, high fault‐impedance tolerability and correctness of the proposed protection method.
Multi‐variable constrained non‐linear optimal planning and operation problem for isolated microgrids with stochasticity in wind, solar, and load demand data
Authors: Kumar Maneesh , Tyagi Barjeev
Published: February 2020

A microgrid (MG) is a cluster of small‐scale sources known as micro‐sources, the energy storage devices, and the loads. MGs are promising entities that allow a considerable amount of renewable energy penetration into the system. A stochastic optimisation model is presented in this study to find the optimal size of the distributed energy resources (DERs). The uncertainties are considered with the help of multiple scenarios of random variables viz. wind output, solar output, and load demand data. A particular case of Beta distribution is used to create these variations. A cost‐based, multi‐variable constrained non‐linear objective function is formulated. The considered test MG system is more generalized with solar and wind energy penetration. The results show the effect of operational as well as the planning aspects together under various reliability conditions for an isolated MG. The formulated problem is solved to obtain a global optimal solution using a sequential programming approach and a comparative assessment of results with a hybrid particle swarm optimisation (PSO) approach has also been presented. It is found that the results obtained from the sequential programming approach are better compared to the hybrid PSO approach.
Reactive power planning using convex line‐wise power balance equations for radial distribution systems
Authors: Aldik Abdelrahman , Venkatesh Bala
Published: February 2020

Optimal capacitor placement for radial distribution systems (RDSs) considers minimising the total cost of new fixed capacitors, switchable capacitors, and losses, while satisfying power balance equations, limits on bus voltages and capacitor limits. It is a non‐convex mixed‐integer non‐linear programming (MINLP) challenge. In this study, the authors propose a solution method using a line‐wise model (LWM) of power balance equations. First, equations for LWM are presented with their Jacobian for solving the power flow problem using Newton–Raphson method. Then, an optimal non‐convex MINLP capacitor placement formulation with LWM power balance equations is presented. Thereafter, it is transformed into a convex mixed‐integer conic programming formulation using second‐order conic relaxation. Both the non‐convex and convex optimal capacitor placement formulations are used to study 69‐bus and 136‐bus RDS. The results are compared with a formulation that uses the branch flow model (BFM) for power balance equations. Results show that the non‐convex LWM‐based formulation is twice as fast when compared with the BFM‐based formulation. The convex LWM‐based formulation is from 4 to 30 times as fast when compared with the BFM‐based formulation, demonstrating the benefits of the use of the LWM‐based formulation for enhancing the solution space of the optimisation problem.
Long‐distance wireless power transfer system powering multiple loads with constant voltage outputs using S‐SP compensation
Authors: Cheng Chenwen , Zhou Zhe , Li Weiguo , Lu Jianghua , Deng Zhanfeng , Mi Chunting Chris
Published: February 2020

This paper proposes a long‐distance multi‐load wireless power transfer (WPT) system with a constant voltage (CV) output for each load. A repeater unit consisting of two bipolar repeater coils is designed to power the load. Multiple repeater units are placed in a line and the power can be transferred from one unit to the next. Each repeater unit corresponds to one load and multiple loads can be powered simultaneously. The two repeater coils in the same repeater unit are placed perpendicularly to eliminate the magnetic coupling between them. In each repeater unit, a compensation capacitor is placed in series with the transmitting coil while two extra compensation capacitors form a series‐parallel (SP) structure for the receiving coil. When neglecting the coil's parasitic resistance, the CV characteristics can be obtained, which enables the independent and flexible power control of each load. Moreover, the influence of the parasitic resistances on the system performance is analysed. Such a system is especially suitable for powering the gate drivers in a high‐voltage converter where multiple insulated gate bipolar transistors (IGBTs) are connected in series. An experimental setup with six loads is constructed to validate the proposed system. The maximum system efficiency can reach 88.1%.
Das Telenotarztsystem – Potentiale für die präklinische Notfallversorgung im ländlichen Raum
Authors: Süss Rebekka , Dewenter Caterina , Ekinci Aylin , Laslo Timm , Fleßa Steffen
Published: February 2020

Zielsetzung Der Landkreis Vorpommern-Greifswald steht aufgrund seiner ländlichen Prägung vor steigenden Herausforderungen in der präklinischen Notfallversorgung. Der Telenotarzt als Innovation ist in diesem Bereich seit 2017 im Landkreis im Rahmen eines Projektes im Einsatz. Mittels einer Analyse realer Einsatzdaten sollte die avisierte Verbesserung der Notfallversorgung durch das Telenotarztsystem untersucht werden.

Methodik Die Datenbasis stellen die Einsatzdaten aus dem Eigenbetrieb Rettungsdienst Greifswald dar und umfassen Informationen zu den Rettungswagen und Notarzteinsatzfahrzeugen. Diese Daten aus den Jahren 2016 und 2018 wurden bereinigt und gegenübergestellt. Anschließend erfolgte die Verknüpfung mit den Einsatzdaten des Telenotarztes aus dem Jahr 2018. Insbesondere wurden dabei die Einsatzhäufigkeiten und die Bindungsdauern des Personals Notarzt und Telenotarzt analysiert.

Ergebnisse Die Analyse zeigt, dass der Anteil der Notarztbeteiligung an allen Fällen im Jahr 2016 bei 14 458 von 27 302 Fällen beträgt und im Jahr 2018 14 683 von 30 927 Fällen. Es ergibt sich eine Reduktion um 5,5 %. Zusätzlich war in 86,6 % aller Telenotarzt-Einsätze kein konventioneller Notarzt beteiligt. In Bezug auf die Bindungsdauer der Ressource Notarztpersonal und Telenotarzt zeigt sich deutlich, dass ein Notarzt im Mittel mehr als doppelt so lang im Einsatz gebunden ist wie ein Telenotarzt.

Schlussfolgerung Es konnte erfolgreich gezeigt werden, dass die Ressource Notarztpersonal durch die Einführung eines Telenotarztsystems effizienter eingesetzt werden kann. Das große Potential des Telenotarztes, den Notarzt zukünftig zu unterstützten und zu entlasten, stellt insbesondere für den ländlichen Raum eine vielversprechende Lösung in der präklinischen Notfallversorgung dar.
Anti-amoebic Activity of Leaf Extracts and Aporphine Alkaloids Obtained from Annona purpurea
Authors: Díaz-Godínez César , Ontiveros-Rodríguez Julio C. , Ríos-Valencia Diana G. , Herbert-Pucheta José Enrique , Zepeda-Vallejo L. Gerardo , Carrero Julio César
Published: February 2020

Annona purpurea has been traditionally used by indigenous and socioeconomically disadvantaged people to treat infectious and parasitic diseases, including amoebiasis. The goal of this study was to assess the effect of a crude methanolic extract, an alkaloid extract, and aporphine alkaloids from leaves of A. purpurea on the viability of Entamoeba histolytica trophozoite cultures and to identify the mechanism of action. Different concentrations of the extracts and alkaloids purpureine (1), 3-hydroxyglaucine (2), norpurpureine (3) glaziovine (4), and oxopurpureine (5) were added to the cultures, and dead parasites were counted after 24 h using a tetrazolium dye reduction assay and analyzed by flow cytometry. The crude extract did not affect the viability of amoebae, but the alkaloid extract and the derived alkaloid glaziovine (4) had important anti-amoebic activity with an IC50 of 33.5 µM compared to that shown by metronidazole (6.8 µM). The treatments induced significant morphological changes in the trophozoites, and most parasites killed by the alkaloid extract were positive for Annexin V, suggesting that apoptosis was the main mechanism of action. In contrast, glaziovine (4) induced less apoptosis with more amoebic lysis. This study supports the idea that aporphine alkaloids from A. purpurea, mainly (+)-(R)-glaziovine (4), could contribute to the development of new formulations for the treatment of amoebiasis. In addition, X-ray diffraction structural analysis and complete 1H and 13C NMR assignments of (+)-(R)-glaziovine (4) were performed and reported for the first time.
Aspectos clínicos e radiográficos de pacientes com síndrome do impacto femoroacetabular: Há diferença entre quadril sintomático e assintomático?
Authors: Silva Andreza Maroneze , Nakatake Flávia Marques , Neves Maria Cristina Arruda , Alves Vera Lúcia Santos , Polesello Giancarlo Cavalli
Published: February 2020

Objetivos Comparar características clínicas e radiográficas entre quadril sintomático e assintomático em pacientes com síndrome do impacto femoroacetabular unilateral e estabelecer correlações entre os achados.

Métodos Estudo retrospectivo, que consultou prontuários de pacientes com síndrome do impacto femoroacetabular, entre janeiro de 2014 e abril de 2017. Os pacientes foram avaliados clinicamente pelo questionário International Hip Outcome Tool 33 (iHOT33), escala visual analógica de dor, amplitude de rotação de quadril e força muscular de quadril e joelho. A avaliação radiográfica foi composta por mensurações do ângulo alfa, sinal do cruzamento, índice de retroversão acetabular, sinal da espinha isquiática e sinal da parede posterior do acetábulo.

Resultados Foram incluídos no estudo 45 prontuários de pacientes, com tempo médio de sintomas até o diagnóstico de 28,6 meses e pontuação média no iHOT33 de 39,9. O valor médio de rotação medial do quadril sintomático foi de 20,5° e do assintomático 27,2°, com (p < 0,001). A positividade do sinal do cruzamento para quadril sintomático foi de 68,9% e do assintomático 55,6% (p = 0,03). Para índice de retroversão, o valor médio do quadril sintomático foi de 0,15 e do quadril assintomático foi 0,11 (p = 0,02). Encontramos correlação positiva entre o tempo de sintomas e a redução de amplitude de rotação medial de quadril (p = 0,04) e entre o índice de massa corpórea (IMC) e a redução amplitude de rotação medial de quadril (p = 0,02).

Conclusão Ao comparar características clínicas e radiográficas, observamos redução de rotação medial e aumento do índice de retroversão acetabular no quadril sintomático, bem como associação entre o longo tempo de sintoma e o IMC elevado com perda de rotação medial dos quadris.
Heart Failure Dashboard Design and Validation to Improve Care of Veterans
Authors: Foster Marva , Albanese Catherine , Chen Qiang , Sethares Kristen A. , Evans Stewart , Lehmann Lisa Soleymani , Spencer Jacqueline , Joseph Jacob
Published: February 2020

Background Early electronic identification of patients at the highest risk for heart failure (HF) readmission presents a challenge. Data needed to identify HF patients are in a variety of areas in the electronic medical record (EMR) and in different formats.

Objective The purpose of this paper is to describe the development and data validation of a HF dashboard that monitors the overall metrics of outcomes and treatments of the veteran patient population with HF and enhancing the use of guideline-directed pharmacologic therapies.

Methods We constructed a dashboard that included several data points: care assessment need score; ejection fraction (EF); medication concordance; laboratory tests; history of HF; and specified comorbidities based on International Classification of Disease (ICD), ninth and tenth codes. Data validation testing with user test scripts was utilized to ensure output accuracy of the dashboard. Nine providers and key senior management participated in data validation.

Results A total of 43 medical records were reviewed and 66 HF dashboard data discrepancies were identified during development. Discrepancies identified included: generation of multiple EF values on a few patients, missing or incorrect ICD codes, laboratory omission, incorrect medication issue dates, patients incorrectly noted as nonconcordant for medications, and incorrect dates of last cardiology appointments. Continuous integration and builds identified defects—an important process of the verification and validation of biomedical software. Data validation and technical limitations are some challenges that were encountered during dashboard development. Evaluations by testers and their focused feedback contributed to the lessons learned from the challenges.

Conclusion Continuous refinement with input from multiple levels of stakeholders is crucial to development of clinically useful dashboards. Extraction of all relevant information from EMRs, including the use of natural language processing, is crucial to development of dashboards that will help improve care of individual patients and populations.
Delayed-Interval Delivery in Dichorionic Twin Pregnancies: A Case Report of 154 Latency Days
Authors: de Frias Catarina Alexandra Soares , Queirós Alexandra Sofia Puga Alvarez de Faria , Simões Helena Teresinha Fernandes
Published: February 2020

Premature delivery often complicates multifetal pregnancies, placing neonates at risk of serious morbidity and mortality. In select cases, preterm birth of one sibling may not require delivery of the remaining fetus(es), which may remain in utero for a delayed-interval delivery, consequently improving neonatal morbidity and mortality. Currently, there is no consensus on the best protocol for the optimal management of these cases. We report one case of delayed-interval delivery of a dichorionic pregnancy assisted in our center. In this case, prophylactic cerclage, tocolytic therapy and administration of broad-spectrum prophylactic antibiotics enabled delivery at 37 weeks, corresponding to 154 days of latency, which is, to our knowledge, the longest interval described in the literature. The attempt to defer the delivery of the second fetus in peri-viability is an option that should be offered to parents after counseling, providing that the clinical criteria of eligibility are fulfilled. The correct selection of candidates, combined with the correct performance of procedures, as well as fetal and maternal monitoring and early identification of complications increase the probability of success of this type of delivery.
The Etiology of Neonatal Intensive Care Unit Death in Extremely Low Birth Weight Infants: A Multicenter Survey in China
Authors: Zhou Jianguo , Ba Yin , Du Yang , Lin Sam Bill , Chen Chao ,   on behalf of the Chinese Collaborative Study Group for Etiologies of NICU Deaths
Published: February 2020

Objective The aim of this study is to identify causes of neonatal intensive care unit (NICU) death in extremely low birth weight (ELBW) infants less than 1,000 g admitted in Chinese tertiary NICUs.

Study design We retrospectively collected data on 607 ELBW infants from 39 level III NICUs from July 2016 to June 2019. The primary causes of death were compared among different gestation age, postnatal age groups, and areas with variable economic status.

Results Among all 607 ELBW NICU deaths, 47.1% were multiple gestation with high rate of in vitro fertilization (IVF) (43.3%); 53.4 and 34.1% received any or full course of antenatal corticosteroid (ACS). The most common causes of ELBW NICU death were respiratory distress syndrome-related neonatal respiratory failure (RDS-NRF, 43.5%), severe infection (19.1%), necrotizing enterocolitis or bowel perforation (9.4%), severe central nervous system injury (8.4%), and bronchopulmonary dysplasia-related respiratory failure (BPD-NRF, 7.7%). Causes of ELBW NICU death varied across postnatal age groups. RDS-NRF was the leading cause of early neonatal death, while severe infection in late neonatal death and BPD in postneonatal EBLW NICU death. RDS-NRF, severe brain injury, and asphyxia were most likely to die at early neonatal age (median age [interquartile range], 2 [0–5], 6 [3–9], and 3 [1–6] days, respectively) while severe infection and necrotizing enterocolitis (NEC) at late neonatal age, BPD-NRF at postneonatal age.

Conclusion In Chinese tertiary NICUs, the major causes of death in extremely low birth weight infants were RDS, infection, NEC, brain injury and BPD, and they varied with postnatal age. Developing specific prevention strategies for identified causes of death in ELBW NICU may potentially improve ELBW survival.
Laser intensity scaling of the magnetic field from a laser-driven coil target
Authors: Williams G. J. , Patankar S. , Mariscal D. A. , Tikhonchuk V. T. , Bude J. D. , Carr C. W. , Goyon C. , Norton M. A. , Pollock B. B. , Rubenchik A. M. , Swadling G. F. , Tubman E. R. , Moody J. D.
Published: February 2020

We report on the first direct voltage and current measurements from a laser-generated magnetic field coil target. The magnetic field was observed to scale with the laser intensity as B∝Ilaser0.66±0.13. This scaling relation can be derived from the measured voltage approximated by the laser-heated plasma electron temperature Te. The experiments used a 1053 nm laser with pulse lengths ranging from 0.5 to 20 ns and intensities ranging from 109 to 1014W/cm2 to generate an electric potential that drives current through the coil. We show that the behavior of the coil can be described with a lumped-element circuit model.
Tunable photoelectronic properties of hydrogenated-silicene/halogenated-silicene superlattices for water splitting
Authors: Chen Hao , Yan Pinglan , Li Jin , He Chaoyu , Ouyang Tao , Zhang Chunxiao , Tang Chao , Zhong Jianxin
Published: February 2020

We propose a novel two-dimensional (2D) lateral superlattice based on silicene alternately saturated by hydrogen and halogen atoms, named as hydrogenated-silicene/halogenated-silicene superlattices (SHSXSLs, X = F, Cl, Br, and I). Employing ab initio electronic calculations, we systematically investigate the structural, electronic, and optical properties of SHSXSLs. Our results show that these superlattices are much stable than silicene as saturating the dangling bonds and the bandgap and carrier effective mass of superlattices can be modulated by the width of components due to the confinement and interfacial effects. By calculating the band alignment, it is found that all superlattices exhibit the type I alignment. Specifically, SHSCl,BrSLs have very small valence band offset and large conduction band offset, which can separate electrons and holes in these systems. Furthermore, the band edge positions of SHSCl,BrSLs satisfy the redox potential of the water splitting and SHSCl,BrSLs exhibit strong absorption in the visible region, suggesting that these superlattices are promising materials for photovoltaics and photocatalytics. This new type of superlattice structure can be applied to other 2D materials with strong activity to enhance the stability and modulate the properties effectively.
Point defects in BaSi2 thin films for photovoltaic applications studied by positron annihilation spectroscopy
Authors: Montes A. , Eijt S. W. H. , Tian Y. , Gram R. , Schut H. , Suemasu T. , Usami N. , Zeman M. , Serra J. , Isabella O.
Published: February 2020

Barium di-silicide (BaSi2) is a very promising absorber material for high-efficiency thin-film solar cells, due to its suitable bandgap, high light absorption coefficient, and long minority-carrier lifetime. In this study, we compare the nanostructure, layer composition, and point defects of BaSi2 thin films deposited by Radio Frequency (RF) sputtering, Thermal Evaporation (TE), and Molecular Beam Epitaxy (MBE), using Doppler Broadening Positron Annihilation Spectroscopy (DB-PAS) depth profiling, Raman spectroscopy, and x-ray diffraction. Our DB-PAS study on thermally annealed RF-sputter deposited and on TE-deposited BaSi2 layers, in a comparison with high quality BaSi2 films produced by MBE, points to the presence of vacancy-oxygen complexes and Si or Ba mono-vacancies, respectively, in the (poly)crystalline BaSi2 films. The degree of near-surface oxidation increases, going from MBE and TE to the industrially applicable RF-sputtered deposition synthesis. The use of a-Si capping layers on the thermally annealed RF-sputtered BaSi2 films leads to a clear reduction in sub-surface oxidation and improves the quality of the BaSi2 films, as judged from DB-PAS.
Kinetic model of an inverted sheath in a bounded plasma system
Authors: Gyergyek T. , Kovačič J. , Gomez I. , Gunn J. P. , Costea S. , Mozetič M.
Published: February 2020

A one-dimensional, kinetic model of inverted sheath formation in a plasma system bounded by two infinitely large planar electrodes (the source and the collector) has been developed for the first time. It is assumed that ions and electrons are injected into the system from the source with half-Maxwellian distributions, and emitted electrons are also injected from the collector with a half-Maxwellian distribution. It is assumed that the potential increases monotonically from the source to the collector. Consequently, the distribution functions of ions, electrons, and emitted electrons anywhere in the system can be written as functions of the potential. Zero and first moments of the distribution functions give particle densities and fluxes. From these, the floating condition for the collector is derived and the Poisson equation is written. The first integrals of the Poisson equation give the conditions for the electric field at the source and at the collector. The model consists of five basic equations: (1) collector floating condition, (2) neutrality condition at the inflection point of the potential, (3) source electric field condition, (4) collector electric field condition, and (5) Poisson equation. The model contains nine parameters. Five of them are plasma parameters: (1) ion mass μ, (2) ion temperature τ, (3) ion source strength α, (4) temperature of emitted electrons σ, and (5) emission coefficient ε. Then there are two potentials, (1) floating potential of the collector ΨC and potential at the inflection point ΨP and (2) electric fields, (1) electric field at the collector ηC and (2) electric field at the source ηS. If five of them are selected, the other four can be found from the system of equations (1)–(4). Numerical solutions of the Poisson equation give axial profiles of the potential, electric field, and space charge density. The model can be used for parametric analysis of the inverted sheath formation. Usually μ, τ, α, ε, and σ are selected and then ΨC, ΨP, ηC, and ηS are found from the system of equations (1)–(4). This means that the particle densities are selected independently, but the potentials and electric fields are then calculated in a self-consistent way with the selected parameters.
Effect of added surfactant on convective assembly of monosized microspheres
Authors: Joshi Kedar , Gilchrist James F.
Published: February 2020

Convective deposition has become one of the common techniques for obtaining a colloidal assembly with a desired number of layers/thickness. Many applications in photonics and semiconductor industries demand only a single layer of colloids placed in a reproducible manner. In the convective deposition, a deposition velocity is typically inversely correlated with a number of layers. Obtaining a uniform monolayer reproducibly thus requires maintaining precise conditions such as the pH, volume fraction, ionic strength of the suspension, temperature, and humidity. Maintaining ideal conditions is one of the limiting factors for the scale-up of convective deposition. Likewise, the surface chemistry must also be reproducible. In the following study, we have demonstrated the effect of the sodium dodecyl sulfate (SDS) surfactant on convective deposition. We show that added SDS alters the flow patterns inside the thin film through Marangoni-driven surface stress, which then alters the time for the assembly. The added surfactant can permit more reliable conditions for monolayer coatings. This study using controlled amounts of the surfactant may give a broader understanding of variability of results found in the literature.
GaSb diode lasers tunable around 2.6
μ
m using silicon photonics resonators or external diffractive gratings
Authors: Ojanen S.-P. , Viheriälä J. , Cherchi M. , Zia N. , Koivusalo E. , Karioja P. , Guina M.
Published: February 2020

We report two tunable diode laser configurations emitting around 2.6 μm, where the gain is provided by a high-gain GaSb-based reflective semiconductor optical amplifier. The lasers are driven in pulsed mode at 20 °C, with a pulse width of 1 μs and 10% duty cycle to minimize heating effects. To demonstrate the broad tuning and high output power capability of the gain chip, an external cavity diode laser configuration based on using a ruled diffraction grating in a Littrow configuration is demonstrated. The laser shows a wide tuning range of 154 nm and a maximum average output power on the order of 10 mW at 2.63 μm, corresponding to a peak power of 100 mW. For a more compact and robust integrated configuration, we consider an extended-cavity laser design where the feedback is provided by a silicon photonics chip acting as a reflector. In particular, the integrated tuning mechanism is based on utilizing the Vernier effect between two thermally tunable micro-ring resonators. In this case, a tuning range of around 70 nm is demonstrated in a compact architecture, with an average power of 1 mW, corresponding to a peak power of 10 mW.
Transforming pool boiling into self-sustained flow boiling through bubble squeezing mechanism in tapered microgaps
Authors: Chauhan A. , Kandlikar S. G.
Published: February 2020

We demonstrate a mechanism to transform a pool boiling system into a self-sustained flow boiling system through bubble-induced two-phase flow in a tapered microgap over the heater surface. The nucleating bubbles in the gap are squeezed and expand preferentially in the increasing taper direction. The expanding flow cross section decelerates the two-phase flow and converts the momentum loss into pressure buildup. The bubble squeezing and the pressure recovery effects overcome the frictional and acceleration pressure drops to provide a net pumping head. We hypothesize that the resulting self-sustained flow eliminates the need for an external pump and transforms a pool boiling system into a pumpless flow boiling system with significantly higher heat transfer potential. Experiments were carried out with water in 10° and 15° tapered gaps over a 10 mm square heater surface with an inlet gap height of 1.27 mm. The plain heater surface with a 15° tapered gap reached a critical heat flux of 288 W/cm2 with a heat transfer coefficient of 119 kW/m2 °C as compared to 127 W/cm2 and 52.5 kW/m2 °C with only a plain surface. High-speed imaging revealed that the bubbles nucleating at the entrance in the gap are squeezed and expand in the increasing cross section direction. A homogeneous flow model was used for pressure drop analysis in the expanding gap. The results indicate that the pressure recovery mechanism alone cannot sustain the flow and the bubble squeezing action plays a critical role in establishing the self-sustained flow.
Enhancing the spin Seebeck effect by controlling interface condition in Pt/polycrystalline nickel ferrite slabs
Authors: Kim Minyoung , Park Sang J. , Jin Hyungyu
Published: February 2020

The spin Seebeck effect (SSE) is an emergent thermoelectric phenomenon, which enables a thermal-to-electrical energy conversion via the thermal injection of spin currents from a ferromagnet (FM) into an attached paramagnetic metal (PM). Recent studies have revealed that the SSE is very sensitive to the PM/FM interface condition, suggesting a potential way to enhance the SSE by controlling the interface condition. However, most of the previous studies are limited to conventional Pt/bulk single-crystal or thin-film YIG systems, lacking consideration for mesoscale surface defects such as pores and grain grooves, which frequently exist in more prevalent bulk polycrystalline magnets. Here, we investigate the effect of interface condition on the longitudinal SSE (LSSE) in a Pt/polycrystalline NiFe2O4 (NFO) slab system. Different interface conditions are induced by treating the surface of NFO slabs with varying combinations of polishing force (Fp) and post-annealing temperature (Ta) before the Pt deposition. The resultant LSSE signals show strong correlations with different interface parameters. In particular, we find that mesoscale surface defects (cracks, pores, and grain grooves) and the surface roughness play a crucial role in determining the magnitude of LSSE signals and demonstrate that those parameters can be deliberately controlled by properly choosing Fp and Ta. We report one sample with a spin Seebeck coefficient of 0.58 μV/K, which is significantly larger than that of bulk polycrystalline magnets reported thus far.