bluuebunny/crossref_metadata_2025 huggingface dataset:
Bliss' and Loewe's additive and synergistic effects in Plasmodium falciparum growth inhibition by AMA1-RON2L, RH5, RIPR and CyRPA antibody combinations
Authors: Azasi Yvonne , Gallagher Shannon K. , Diouf Ababacar , Dabbs Rebecca A. , Jin Jing , Mian Syed Yusuf , Narum David L. , Long Carole A. , Gaur Deepak , Draper Simon J. , Fay Michael P. , Miller Louis H. , Miura Kazutoyo
Published: July 2020

Plasmodium invasion of red blood cells involves malaria proteins, such as reticulocyte-binding protein homolog 5 (RH5), RH5 interacting protein (RIPR), cysteine-rich protective antigen (CyRPA), apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2), all of which are blood-stage malaria vaccine candidates. So far, vaccines containing AMA1 alone have been unsuccessful in clinical trials. However, immunization with AMA1 bound with RON2L (AMA1-RON2L) induces better protection against P. falciparum malaria in Aotus monkeys. We therefore sought to determine whether combinations of RH5, RIPR, CyRPA and AMA1-RON2L antibodies improve their biological activities and sought to develop a robust method for determination of synergy or additivity in antibody combinations. Rabbit antibodies against AMA1-RON2L, RH5, RIPR or CyRPA were tested either alone or in combinations in P. falciparum growth inhibition assay to determine Bliss' and Loewe's additivities. The AMA1-RON2L/RH5 combination consistently demonstrated an additive effect while the CyRPA/RIPR combination showed a modest synergistic effect with Hewlett’s $$S=1.07 \left[95\% \mathrm{C}\mathrm{I}: 1.03, 1.19\right].$$

S
=
1.07

95
%
C
I
:
1.03
,
1.19

.

Additionally, we provide a publicly-available, online tool to aid researchers in analyzing and planning their own synergy experiments. This study supports future blood-stage vaccine development by providing a solid methodology to evaluate additive and/or synergistic (or antagonistic) effect of vaccine-induced antibodies.
Effect of undissolved Nb carbides on mechanical properties of hydrogen-precharged tempered martensitic steel
Authors: Seo Hyun Joo , Jo Jang Woong , Kim Jae Nam , Kwon Kitae , Lee Junmo , Choi Sangwoo , Lee Taekyung , Lee Chong Soo
Published: July 2020

Nb carbides have attracted significant attention to enhance the resistance of tempered martensitic (TM) steel to hydrogen embrittlement (HE). However, previous studies have elucidated the role of Nb carbides in HE resistance without categorizing their types (i.e., undissolved and newly precipitated). This study focuses on the effect of “undissolved” Nb carbides on the tensile and fatigue properties of hydrogen-precharged TM steels. It validated the following two factors for the HE resistance of the TM steels containing undissolved Nb carbides: hydrogen-trapping by the carbides and refinement of prior austenite grain. The former factor rarely affected the HE resistance owing to the interfacial incoherency between the undissolved carbides and ferritic matrix. Such results are distinguished from previous studies focusing on the newly precipitated carbides. In contrast, the latter factor contributed significantly to the HE resistance via the decrease in hydrogen contents per unit surface of prior austenite grain boundaries.
Effect of the submandibular push exercise using visual feedback from pressure sensor: an electromyography study
Authors: Park Sungwon , Cho Joo Young , Lee Byung Joo , Hwang Jong-Moon , Lee Myunghwan , Hwang Soo Yeon , Kim KwanMyung , Lee Ki Hoon , Park Donghwi
Published: July 2020

We developed a new exercise method called the submandibular push exercise that can strengthen the suprahyoid muscle by inducing only the motion of the hyoid bone without neck flexion. In this study, we aimed to investigate and compare the muscle activity of the suprahyoid and infrahyoid muscles in the course of performing three different swallowing exercises. Twenty healthy participants and fifteen patients with dysphagia were recruited. Each participant consecutively performed three exercises: Shaker, CTAR, and submandibular push exercises. To investigate muscle activation, surface electromyography was performed on the suprahyoid, infrahyoid, and SCM muscles, during the exercises. Root mean square (RMS) was measured. In healthy participants, the submandibular push exercise showed a significantly higher RMS value in the suprahyoid and infrahyoid muscles than the Shaker and CTAR exercises using repeated ANOVA with Tukey's post hoc test (p < 0.05). In patients with dysphagia, the submandibular push and Shaker exercises showed significantly higher RMS value in the suprahyoid and infrahyoid muscles than the CTAR exercise. However, no significant difference was found between the submandibular push and Shaker exercises. In both healthy and patients with dysphagia, the mean RMS values of the SCM muscles during the submandibular push exercise were significantly lower than those during the Shaker exercise using repeated ANOVA with Tukey's post hoc test (p < 0.05). In conclusion, considering the relatively superior selectiveness in suprahyoid and infrahyoid muscle contraction, the submandibular push exercise using visual feedback from pressure sensor could be an efficient supplementary exercise to the conventional swallowing muscle exercises. However, further studies may be necessary to confirm the improvement in swallowing difficulty.
Chemokine receptor CXCR7 non-cell-autonomously controls pontine neuronal migration and nucleus formation
Authors: Zhu Yan , Hirata Tatsumi , Mackay Fabienne , Murakami Fujio
Published: July 2020

Long distance tangential migration transports neurons from their birth places to distant destinations to be incorporated into neuronal circuits. How neuronal migration is guided during these long journeys is still not fully understood. We address this issue by studying the migration of pontine nucleus (PN) neurons in the mouse hindbrain. PN neurons migrate from the lower rhombic lip first anteriorly and then turn ventrally near the trigeminal ganglion root towards the anterior ventral hindbrain. Previously we showed that in mouse depleted of chemokine receptor CXCR4 or its ligand CXCL12, PN neurons make their anterior-to-ventral turn at posteriorized positions. However, the mechanism that spatiotemporally controls the anterior-to-ventral turning is still unclear. Furthermore, the role of CXCR7, the atypical receptor of CXCL12, in pontine migration has yet to be examined. Here, we find that the PN is elongated in Cxcr7 knockout due to a broadened anterior-to-ventral turning positions. Cxcr7 is not expressed in migrating PN neurons en route to their destinations, but is strongly expressed in the pial meninges. Neuroepithelium-specific knockout of Cxcr7 does not recapitulate the PN phenotype in Cxcr7 knockout, suggesting that CXCR7 acts non-cell-autonomously possibly from the pial meninges. We show further that CXCR7 regulates pontine migration by modulating CXCL12 protein levels.
Publisher Correction: Multi-decadal to centennial hydro-climate variability and linkage to solar forcing in the Western Mediterranean during the last 1000 years
Authors: Brahim Yassine Ait , Wassenburg Jasper A. , Cruz Francisco W. , Sifeddine Abdelfettah , Scholz Denis , Bouchaou Lhoussaine , Dassié Emilie P. , Jochum Klaus P. , Edwards R. Lawrence , Cheng Hai
Published: July 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Machine learning the ropes: principles, applications and directions in synthetic chemistry
Authors: Strieth-Kalthoff Felix , Sandfort Frederik , Segler Marwin H. S. , Glorius Frank
Published: July 2020

Chemists go ML! This tutorial review provides easy access to the fundamentals of machine learning from a synthetic chemist's perspective. Its diverse applications for molecular design, synthesis planning, or reactivity prediction are summarized.
Giant room-temperature barocaloric effect at the electronic phase transition in Ni1−xFexS
Authors: Lin Jianchao , Tong Peng , Zhang Xuekai , Wang Zichen , Zhang Zhao , Li Bing , Zhong Guohua , Chen Jie , Wu Yaoda , Lu Huaile , He Lunhua , Bai Bo , Ling Langsheng , Song Wenhai , Zhang Zhidong , Sun Yuping
Published: July 2020

The electronic entropy enhanced giant barocaloric effect along with high thermal conductivity in hexagonal Ni1−xFexS.
Ratiometric fluorescent probe with aggregation-induced emission features for monitoring HClO in living cells and zebra fish
Authors: Li Yanfei , Li Hui , Di Guilan
Published: July 2020

Herein, we present a ratiometric fluorescent probe, PTZ-HClO, with unique optical performance and aggregation-induced emission features that can simultaneously detect HClO.
Improved magnetic lateral flow assays with optimized nanotags for point-of-use inductive biosensing
Authors: Salvador María , Gallo-Cordova Álvaro , Moyano Amanda , Martínez-García J. Carlos , Blanco-López M. Carmen , Puerto Morales M. , Rivas Montserrat
Published: July 2020

Magnetic nanotags in lateral flow immunoassay for inductive biosensing: clusters of superparamagnetic critical size optimize the reading out.
Addressing regio- and stereo-specificity challenges in the synthesis of nucleoside 2′,3′-cyclic monophosphate analogs – a rapid and facile synthesis of nucleoside-2′,3′-O,O-phosphoro-thioate or -selenoate, and elucidation of the origin of the rare specificity
Authors: Nassir Molhm , Balaom Lara , Fischer Bilha
Published: July 2020

A new facile, rapid, stereo- and regio-selective one-pot synthesis of nucleoside-2′,3′-O,O-phosphorothioate and selenoate analogs has been developed.
Two-step gas adsorption induced by the transmetallation in a two-dimensional metal–organic framework
Authors: Park Hye Jeong , Oh Jongbum , Kim Jiwon , Kim Jaheon
Published: July 2020

Transmetallation of Zn2+ with Cu2+ in a two-dimensional metal–organic framework, Zn3(TCPB)2(H2O)2 (H3TCPB = 1,3,5-tri(4-carboxyphenoxy)benzene), leads to two-step and reversible gas adsorption.
Stereoselective aminosulfonylation of alkynes: an approach to access (Z)-β-amino vinylsulfones
Authors: Ansari Mohd Yeshab , Swarnkar Sumedha , Kumar Atul
Published: July 2020

The stereoselective aminosulfonylation of alkynes in a syn mode is accomplished using sodium sulfinates and azoles, in the presence of I2/base and afforded the (Z)-β-amino vinylsulfones in good yields.
Controlled O2reduction at a mixed-valent (II,I) Cu2S core
Authors: Mangue Jordan , Gondre Clément , Pécaut Jacques , Duboc Carole , Ménage Stéphane , Torelli Stéphane
Published: July 2020

Oxygen reduction reactions catalyzed by a mixed-valent copper complex reveal a tuneable H2O2/H2O selectivity at room temperature together with high stability over several cycles.
Topology versus porosity: what can reticular chemistry tell us about free space in metal–organic frameworks?
Authors: Shevchenko Alexander P. , Alexandrov Eugeny V. , Golov Andrey A. , Blatova Olga A. , Duyunova Alexandra S. , Blatov Vladislav A.
Published: July 2020

We analyse 3D coordination networks in 33 790 coordination polymers and discuss relations between their topological and porosity properties.
Recent advances in three-component difunctionalization ofgem-difluoroalkenes
Authors: Liu Chi , Zeng Hao , Zhu Chuanle , Jiang Huanfeng
Published: July 2020

Three-component difunctionalization ofgem-difluoroalkenesviathe generation and transformation of a α-fluoroalkylated carbanion, a carbon–metal species, a radical, and a carbocation intermediate.
Effect of chain architectures on the domain spacing of block copolymers with equivalent segregation degrees
Authors: Ji Xianwen , Li Weihua
Published: July 2020

Effect of chain architectures on the segregation degree of block copolymers.
Temperature sensitivity of nitrate removal in woodchip bioreactors increases with woodchip age and following drying–rewetting cycles
Authors: Maxwell Bryan M. , Díaz-García Carolina , Martínez-Sánchez Juan José , Birgand François , Álvarez-Rogel José
Published: July 2020

Temperature sensitivity of nitrate removal in woodchip bioreactors changes according to short and long-term changes in carbon quality.
Stable white photoluminescence from Mn-contained organic lead bromide perovskite ring arrays formed from 2D colloidal crystal templates
Authors: Xu Jingkun , Qu Junfeng , Shao Haibao , Xu Shuhong , Wang Chunlei , Cui Yiping
Published: July 2020

C4N2H14PbxMn1−xBr4 perovskite ring arrays with stable white light emission and controllable size for high color quality white light-emitting diodes.
DABA MNPs: a new and efficient magnetic bifunctional nanocatalyst for the green synthesis of biologically active pyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin derivatives
Authors: Karami Shahriar , Dekamin Mohammad G. , Valiey Ehsan , Shakib Peyman
Published: July 2020

A new core–shell magnetic silica functionalized with 3,4-diaminobenzoic acid nanocatalyst (Fe3O4@SiO2@PTS-DABA) was prepared and characterized. The Fe3O4@SiO2@PTS-DABA catalyst was applied for the synthesis of dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives.
High rejection performance ultrafiltration membrane with ultrathin dense layer fabricated by the movement and dissolution of metal–organic frameworks
Authors: Wang Qi , Zhang Shaohu , Ji Xiwei , Ran Fen
Published: July 2020

Ultrafiltration membranes have potential to solve the problems of water pollution and shortage.
Synthesis and characterization of ferrous cysteinate nanoparticles as a promising dietary supplement
Authors: Koshcheeva Olga S. , Skiba Tatyana V. , Stabnikov Pavel A. , Maksimovskiy Eugene A. , Zubareva Anna P. , Korolkov Ilya V. , Koshcheev Sergey V. , Alekseeva Zinaida N. , Reimer Vyacheslav A. , Klemeshova Inna Y.
Published: July 2020

Ferrous cysteinate nanoparticles were obtained and characterized for the first time and tested as a feed additive on chickens.
HSA functionalized Gd2O3:Eu3+ nanoparticles as an MRI contrast agent and a potential luminescent probe for Fe3+, Cr3+, and Cu2+ detection in water
Authors: Vashistha Nidhi , Chandra Abhishek , Singh Man
Published: July 2020

PVP capped Gd2O3:Eu3+ (PVP@Gd2O3:Eu3+) and HSA functionalised PVP@Gd2O3:Eu3+ (HSA@PVP@Gd2O3:Eu3+) NPs as fluorescent detection probe for metal ion detection and MRI contrast agent.
Spring-roll-like Ti3C2 MXene/carbon-coated Fe3O4 composite as a long-life Li-ion storage material
Authors: Li Qiang , Zhou Jian , Li Fan , Sun Zhimei
Published: July 2020

Fe3O4 is a promising anode material for Li-ion batteries because of its high theoretical capacity, low cost, and natural abundance.
A high-output flexible triboelectric nanogenerator based on polydimethylsiloxane/three-dimensional bilayer graphene/carbon cloth composites
Authors: Qian Yongteng , Sohn Minkyun , He Wen , Park Hyunje , Subramanian K. R. V. , Kang Dae Joon
Published: July 2020

A high output flexible triboelectric nanogenerator was successfully fabricated through a facile synthetic route which can achieve a high output power density of 0.65 mW cm−2.
Gradient scaffolds for osteochondral tissue engineering and regeneration
Authors: Zhang Bin , Huang Jie , Narayan Roger J.
Published: July 2020

The tissue engineering approach for repairing osteochondral (OC) defects involves the fabrication of a biological tissue scaffold that mimics the physiological properties of natural OC tissue (e.g., the gradient transition between the cartilage surface and the subchondral bone).
Leucine-activated nanohybrid biofilm for skin regeneration via improving cell affinity and neovascularization capacity
Authors: Lin Xiajie , Li Yamin , Luo Wei , Xiao Lan , Zhang Zeren , Zhao Jinzhong , Liu Changsheng , Li Yulin
Published: July 2020

Nanohybrids containing amino acid are doped into biodegradable nanofibrous membranes, which improves the cell affinity, the migration and growth of fibroblasts, and the neovascularization capacity, comprehensively accelerating a rapid wound healing.
Substrate-independent polymer coating with stimuli-responsive dexamethasone release for on-demand fibrosis inhibition
Authors: Yuan Pingyun , Qiu Xinyu , Liu Tao , Tian Ran , Bai Yongkang , Liu Shiyu , Chen Xin , Jin Yan
Published: July 2020

Tissue fibrosis caused by implantation of tissue engineering scaffolds is an urgent problem in clinical research.
Morphological Supports: Investigating Differences in How Morphological Knowledge Supports Reading Comprehension for Middle School Students With Limited Reading Vocabulary
Authors: Goodwin Amanda P. , Petscher Yaacov , Tock Jamie
Published: July 2020

Purpose

The current study takes a practical and theoretically grounded look at assessment of morphological knowledge and its potential to deepen understanding of how morphological knowledge supports reading comprehension for students with limited reading vocabulary. Specifically, we explore how different morphological skills support reading comprehension for students with typical reading vocabulary development compared to students with limited reading vocabulary.

Method

A sample of 1,140 fifth through eighth graders were assessed via a gamified, computer-adaptive measure of language that contained a morphological knowledge assessment. Links to standardized reading comprehension were explored with a focus on determining differences for the 184 students in the sample who showed limited reading vocabulary knowledge. Specifically, multiple regression analyses were used to test for the relation between morphology skills and standardized reading comprehension, as well as the moderator effect of reading vocabulary on the relation between morphological knowledge and standardized reading comprehension.

Results

Findings indicate that the four instructionally malleable morphological skills identified by the assessment differentially supported reading comprehension. These skills were (a) Morphological Awareness, (b) Syntactic Morphological Knowledge, (c) Semantic Morphological Knowledge, and (d) Phonological/Orthographic Morphological Knowledge. Significant interactions for students with limited reading vocabulary were shown in how the skills of Syntactic Morphological Knowledge, Semantic Morphological Knowledge, and Phonological/Orthographic Morphological Knowledge supported standardized Reading Comprehension.

Conclusions

Given the challenges students with limited reading vocabulary have with semantic information, Syntactic Morphological Knowledge and Phonological/Orthographic Morphological Knowledge were particularly supportive, suggesting the compensatory role of these morphological skills. In contrast, Semantic Morphological Knowledge had a negative relationship with Reading Comprehension for students with limited reading vocabulary. Implications for theory, research, and practice are discussed.
Integrating Morphological Awareness in a Multilinguistic Structured Literacy Approach to Improve Literacy in Adolescents With Reading and/or Language Disorders
Authors: Collins Ginger , Wolter Julie A. , Meaux Ashley Bourque , Alonzo Crystle N.
Published: July 2020

Purpose

Reading and writing are language-based skills, and effective literacy instruction/intervention practices should include an explicit linguistic focus. A multilinguistic structured literacy approach that integrates morphological awareness is proven beneficial to improve reading and writing for students with language literacy deficits. The key components of this approach are explored.

Method

An intensive 2-week clinical summer camp, Camp CHRONICLE, which utilizes a multilinguistic structured literacy intervention model that integrates morphological awareness for adolescents with literacy deficits, is reviewed, and three case examples are included.

Conclusion

Multilinguistic structured literacy intervention with a morphological awareness focus is an ideal approach to improve literacy skills of children and adolescents with language literacy deficits.

Supplemental Material

https://doi.org/10.23641/asha.12291029
Forum: Morphological Awareness as a Key Factor in Language-Literacy Success for Academic Achievement
Authors: Meaux Ashley Bourque , Wolter Julie A. , Collins Ginger G.
Published: July 2020

Purpose

This article introduces the
Language, Speech, and Hearing Services in Schools
Forum: Morphological Awareness as a Key Factor in Language-Literacy Success for Academic Achievement. The goal of this forum is to relate the influence morphological awareness (MA) has on overall language and literacy development with morphology acting as the “binding agent” between orthography, phonology, and semantics (
Perfetti, 2007
) in assessment and intervention for school-aged children.

Method

This introduction provides a foundation for MA development and explores the influence MA has over the course of school-aged language and literacy development. Through summaries of the 11 articles in this forum, school-based speech-language pathologists will be able to convey the importance of MA to promote successful educational outcomes for kindergarten to adolescent students. The forum explores researcher-developed assessments used to help identify MA skill level in first- through eighth-grade students at risk for literacy failure to support instructional needs. The forum also provides school-based speech-language pathologists with details to design and implement MA interventions to support academic success for school-aged students with varying speech-language needs (e.g., dual language emersion, vocabulary development, reading comprehension) using various service delivery models (e.g., small group, classroom-based, intensive summer camps).

Conclusion

MA is effective in facilitating language and literacy development and as such can be an ideally focused on using multilinguistic approaches for assessment and intervention. The articles in this issue highlight the importance in assessment measures and intervention approaches that focus on students' MA to improve overall academic success in children of all ages and abilities.
Iodine-Promoted Synthesis of 4-Aryl-2-(arylsulfonyl)quinolones by Desulfurative C–S Cross-Coupling Reaction of Quinoline-2-thiones with Sodium Sulfinates
Authors: Quan Zheng-Jun , Yang Guo-Chao , Wang Xi-Chun
Published: July 2020

An iodine-induced sulfonylation of quinoline-2-thiones with sodium arenesulfinates as sulfur sources for the synthesis of 4-aryl-2-(arylsulfonyl)quinoline derivatives is described. The 4-aryl-2-(arylsulfonyl)quinoline derivatives can be obtained in a moderate to good yields. This C–S bond cleavage and C–S cross-coupling proceeds in the absence of a metal under inexpensive and nontoxic conditions and it displays a broad substrate scope.
Pilot Randomized Controlled Trial of Diabetes Group Prenatal Care
Authors: Carter Ebony B. , Barbier Kate , Hill Pamela K. , Cahill Alison G. , Colditz Graham A. , Macones George A. , Tuuli Methodius G. , Mazzoni Sara E.
Published: July 2020

Objective This study aimed to determine the feasibility and effectiveness of Diabetes Group Prenatal Care to increase patient engagement in diabetes self-care activities.

Study Design A pilot randomized controlled trial was conducted at two sites. Inclusion criteria were English or Spanish speaking, type 2 or gestational diabetes, 22 to 34 weeks of gestational age at first study visit, ability to attend group care at specified times, and willingness to be randomized. Exclusion criteria included type 1 diabetes, multiple gestation, major fetal anomaly, serious medical comorbidity, and serious psychiatric illness. Women were randomized to Diabetes Group Prenatal Care or individual prenatal care. The primary outcome was completion of diabetes self-care activities, including diet, exercise, blood sugar testing, and medication adherence. Secondary outcomes included antenatal care characteristics, and maternal, neonatal, and diabetes management outcomes. Analysis followed the intention-to-treat principle.

Results Of 159 eligible women, 84 (53%) consented to participate in the study and were randomized to group (n = 42) or individual (n = 42) prenatal care. Demographic characteristics were similar between study arms. Completion of diabetes self-care activities was similar overall, but women in group care ate the recommended amount of fruits and vegetables on more days per week (5.1 days/week ± 2.0 standard deviation [SD] in group care vs. 3.4 days ± 2.6 SD in individual care; p < 0.01) and gained less weight per week during the study period (0.2 lbs/week [interquartile range: 0–0.7] vs. 0.5 lbs/week [interquartile range: 0.2–0.9]; p = 0.03) than women in individual care. Women with gestational diabetes randomized to group care were 3.5 times more likely to have postpartum glucose tolerance testing than those in individual care (70 vs. 21%; relative risk: 3.5; 95% confidence interval: 1.4–8.8). Other maternal, neonatal, and pregnancy outcomes were similar between study arms.

Conclusion Diabetes group care is feasible and shows promise for decreasing gestational weight gain, improving diet, and increasing postpartum diabetes testing among women with pregnancies complicated by diabetes.

Key Points
Facility Management: Der Mehrwert des baubegleitenden FM
Authors: Filthuth Heiko
Published: July 2020

Gebaut wird im Krankenhaus fast immer, ob Anbau oder Ersatzneubau, Sanierung, Modernisierung einer technischen Anlage, Verbesserung des Brandschutzes oder ein Modulbau. Diese Maßnahmen haben eines gemeinsam: Ihre Ausführung kostet nur rund zehn Prozent der späteren Bewirtschaftung. Trotzdem liegt der Fokus oft nur auf den Errichtungskosten.
Average field approximation for almost bosonic anyons in a magnetic field
Authors: Girardot Théotime
Published: July 2020

We study the ground state of a large number N of 2D extended anyons in an external magnetic field. We consider a scaling limit where the statistics parameter α is proportional to N−1 when N → ∞, which allows the statistics to be seen as a “perturbation around the bosonic end.” Our model is that of bosons in a magnetic field interacting through long-range magnetic potential generated by magnetic charges carried by each particle, smeared over discs of radius R. Our method allows us to take R → 0 not too fast at the same time as N → ∞ : R = N−1/4+ɛ. We use the information theoretic version of the de Finetti theorem of Brandão and Harrow to justify the so-called “average field approximation”: the particles behave like independent, identically distributed bosons interacting via a self-consistent magnetic field.
Effect of graphene sheet size on exfoliation process in CO2-expanded organic solvent: A molecular dynamics simulation
Authors: Cai Lu , Li Wenxin , Tan Guangsu , Lei De , Liu Zhitian
Published: July 2020

CO2-expanded organic solvents are considered to be the most promising candidates for the liquid-phase exfoliation (LPE) of graphene. Understanding the effect of the initial graphite size on LPE efficiency is important for the production of higher-quality few-layer graphene. The mechanisms involved in the exfoliation process were studied in three different sizes of expanded graphene flakes (with areas of 1.05, 3.78, and 17.92 nm2) in the CO2-expanded solvent by means of molecular dynamics simulations. The simulation results verified at a molecular level that the graphene sheets obtained from small-size expanded graphene have fewer layers than those obtained from large-size expanded graphene. Faster solvent intercalation during the exfoliation process was observed with smaller-sized expanded graphene. Furthermore, an intact solvent monolayer between the graphene sheets and a larger desorption energy barrier with a small expanded graphene size ultimately leads to the rapid formation of a stable and less defective super-burger-like conformation. This enables exfoliation with a considerable yield of mono- or few-layered graphene sheets. We believe that the results reported in this work provide the guidelines for obtaining a high yield of mono- or few-layered graphene by exfoliation with a large sheet area in the CO2-expanded solvent and provide theoretical clues for controlling the size of the graphene sheets produced by exfoliation.
Tuning the magnetic properties of cobalt tetraphenylporphyrin films with oxygen exposure
Authors: Kim Meeri
Published: July 2020

A single molecular layer of cobalt tetraphenylporphyrin grown on top of an iron substrate is exposed to oxygen to investigate the limits of molecule/substrate magnetic coupling.
Quantifying the evaporation rate of sessile droplets using a quartz crystal microbalance
Authors: Murray Brandon , Fox Matthew J. , Narayanan Shankar
Published: July 2020

This study quantifies the evaporation rate of sessile droplets using a quartz crystal microbalance (QCM). Specifically, we analyze the evaporation of water droplets on a gold-coated flat surface exposed to dry nitrogen at different temperatures. In this approach, we use the QCM as a radius sensor and determine the contact angle by droplet imaging, which allows calculating the instantaneous volume and the evaporation rate. For comparison, we quantify evaporation using computational modeling and an experimental technique based on droplet imaging alone. In general, the QCM-based approach was found to provide higher accuracy and a better agreement with the model predictions compared to the approach using imaging only. With modeling and experiments, we also elucidate the role of droplet self-cooling, vapor advection, and diffusion on the net rate of evaporation of sessile droplets. For all the conditions analyzed in this study, the evaporation rate was found to decrease monotonically. We found this reduction to take place even in the presence of a steadily increasing droplet temperature due to a shrinking evaporation area. Considering the vapor transport mechanisms occurring in the ambient, we find diffusion to be the rate-limiting process controlling the net evaporation rate of the droplet.
Experimental analysis of flashing front propagation in superheated water—Effects of degree of superheat, tube inclination, and secondary nucleation
Authors: Dewangan Kush Kumar , Das Prasanta Kumar
Published: July 2020

A comprehensive experimental investigation on free surface flashing and flashing front (FF) propagation after sudden depressurization of stagnant water is reported. Elaborate high-speed imaging and some limited pressure and temperature recording have been made using two experimental facilities. A new rupture mechanism has been developed, which offers a simple operation where the amount of depressurization can be controlled easily and precisely. For the first time, we have quantified the decrease in delay time with the degree of superheat. Facilities have been designed meticulously to cover a reasonable range of operating parameters and to eliminate spurious nucleations. We recorded the evolution and propagation of the free surface FF over the entire length of the test section (500 mm) and observed the propagation to be linear with a strong dependence on the degree of superheat. For the first time, we also reported the effect of secondary nucleation on the FF with elaborate imaging. Finally, we report our observation of FF dynamics in tubes for the entire range of inclinations for which to date no information is available. Our study reveals many unexplored aspects regarding flashing and more crucially pinpoints some important directions in which meticulous experiments are to be conducted in the future to understand this complex phenomenon better.
Elucidating the effect of the ionic liquid type and alkyl chain length on the stability of ionic liquid–iron porphyrin complexes
Authors: Banerjee Atiya , Shah Jindal K.
Published: July 2020

The present study is motivated by the long-term objective of understanding how ionic liquids are biodegraded by cytochrome P450, which contains iron porphyrin (FeP) serving as the catalytic center. To this end, the current study is designed to elucidate the impact of types and conformations of ionic liquids on the binding energy with FeP, the key interactions that stabilize the ionic liquid–FeP complex, and how the electron uptake ability of FeP is altered in the presence of ionic liquids. Four classes of ionic liquids are considered: 1-alkyl-3-methylimidazolium, 1-alkyl-pyridinium, 1-alkylsulfonium, and N-methyl-N-alkylpyrrolidinium. The influence of linear alkyl chains of ethyl, butyl, hexyl, octyl, and decyl is examined on the favorable binding modes with FeP, considering two widely different conformations: tail up and tail down with respect to FeP. Electronic structure calculations are performed at the M06 level of theory with the 6-31G(d,p) basis set for C, H, and N atoms, while the Lanl2DZ basis set is employed for Fe. Donor–acceptor interactions contributing to the binding of ionic liquids to FeP are unraveled through the natural bond orbital analysis. The results from this study indicate that the binding energies are dependent not only on the class of ionic liquids but also on the conformations presented to FeP. The propensity of FeP to acquire an electron is significantly enhanced in the presence of ionic liquid cations, irrespective of the type and the alkyl chain length.
Experimental investigation of turbulent wake flows in a helically wrapped rod bundle in presence of localized blockages
Authors: Nguyen T. , Vaghetto R. , Hassan Y.
Published: July 2020

In nuclear sodium fast reactors, bundles of rods are tightly packed into a triangular lattice, enclosed in a hexagonal duct, and each pin is spirally wrapped with a thin wire. Flow blockages can potentially impact the local flow characteristics and heat transfer mechanisms in the bundle due to its small subchannel size. The effects of the blockage on the flow structures and heat transfer mechanisms are important aspects that require an accurate investigation. In this study, the flow-field characteristics in the vicinity of a blockage located in the exterior subchannel of rod bundles with helically wrapped wires were experimentally investigated. The velocity fields in the exterior subchannel were acquired by applying matched-index-of-refraction and time-resolved particle image velocimetry (TR-PIV) techniques for Reynolds numbers of Re1 = 4000 and Re2 = 17 000, i.e., equivalent to Rew1 = 19 600 and Rew2 = 83 200, respectively, based on the blockage width. The results from the TR-PIV measurements revealed an arch-shaped vortex with a large flow recirculation and a pair of counter-rotating vortices in the wake region downstream of the blockage, which is commonly observed in the wake flow of bluff bodies. The relative lateral distance and angle between the two vortices decreased when the Reynolds numbers increased. Profiles of maximum turbulence intensity along the shear layers illustrated the transition process including the growth, peak, and decay along the flow direction. From the spectral analysis of the turbulent velocities extracted at points along the shear layer, the Strouhal numbers (St) representing the vortex shedding frequency were found to be St = 0.25 and St = 0.56 for the left and right shear layers, respectively. Characteristics of shear layers generated by the blockage in the exterior subchannel were investigated via the two-point cross correlation of fluctuating velocities. The spatiotemporal cross correlations of turbulent velocities, computed at points in the region where the left shear layer exhibited rolling effects and vortex breakdowns, were considerably wider and longer. The convection velocity Uc was estimated to be ∼0.82Um to 0.93Um. Proper orthogonal decomposition (POD) analysis was applied to the instantaneous velocity fields to extract the statistically dominant flow structures. It was found that POD modes 2–3 and 4–5 formed the pair modes when the corresponding POD temporal coefficients depicted sinusoidal shapes and exhibited nearly circular orbits in the phase space. Spectral analysis of the POD temporal coefficients confirmed the vortex shedding frequencies detected in the analysis of turbulent velocities.
Real-time monitoring of surface passivation of crystalline silicon during growth of amorphous and epitaxial silicon layer
Authors: Nunomura Shota , Sakata Isao , Sakakita Hajime , Koga Kazunori , Shiratani Masaharu
Published: July 2020

Surface passivation of crystalline silicon (c-Si) is experimentally studied during the growth of a hydrogenated amorphous silicon (a-Si:H) and epitaxial silicon (epi-Si) passivation layer at a subnanometer to nanometer scale. The property of surface passivation is monitored in real time via in situ measurement of a photocurrent in c-Si under plasma-enhanced vapor deposition for the passivation layer growth. The measurement results suggest the following. Passivation is improved by the growth of an a-Si:H layer, where a large band offset is formed at the a-Si:H/c-Si interface, and the carrier recombination is suppressed. On the other hand, passivation is deteriorated with the growth of an ultrathin epi-Si layer (d≲2.5±1.0 nm) because the band offset is not formed at the interface, and plasma-induced defects are created in c-Si. However, passivation is improved with a thick epi-Si layer (d≳2.5±1.0 nm), where the band bending is formed near the epi-Si/c-Si interface, which partially suppresses the carrier recombination. The suppression of the plasma-induced defects as well as the formation of the band offset are important for surface passivation.
Implementation of the iterative triples model CC3 for excitation energies using pair natural orbitals and Laplace transformation techniques
Authors: Frank Marius S. , Schmitz Gunnar , Hättig Christof
Published: July 2020

We present a pair natural orbital (PNO)-based implementation of CC3 excitation energies, which extends our previously published state-specific PNO ansatz for the solution of the excited state eigenvalue problem to methods including connected triple excitations. A thorough analysis of the equations for the excited state triples amplitudes is presented from which we derive a suitable state-specific triple natural orbital basis for the excited state triples amplitudes, which performs equally well for local and non-local excitations. The accuracy of the implementation is evaluated using a large and diverse test set. We find that for states with small contributions from double excitations, a T0 approximation to PNO-CC3 yields accurate results with a mean absolute error (MAE) for TPNO = 10−7 in the range of 0.02 eV. However, for states with larger double excitation contributions, the T0 approximation is found to yield significantly less accurate results, while the Laplace-transformed variant of PNO-CC3 shows a uniform accuracy for singly and doubly excited states (MAE and maximum error of 0.01 eV and 0.07 eV for TPNO = 10−7, respectively). Finally, we apply PNO-CC3 to the calculation of the first excited state of berenil at a S1 minimum geometry, which is shown to be close to a conical intersection. This calculation in the aug-cc-pVTZ basis set (more than 1300 basis functions) is the largest calculation ever performed with CC3 on excitation energies.
Theory of coherent averaging in magnetic resonance using effective Hamiltonians
Authors: Garg Rajat , Ramachandran Ramesh
Published: July 2020

A perturbative approach based on multimode Floquet theory is proposed to explain the coherent averaging effects of radio frequency pulses on nuclear spins in magnetic resonance experiments. Employing effective Hamiltonians, a uniform description of the time evolution of spins under arbitrary multiple pulse schemes is presented. The choice of interaction frames and transformation functions desired for faster convergence of the perturbation series is identified based on the experimental conditions. We believe that the methodology outlined would be beneficial in the design and optimization of experiments beyond existing strategies.
A theoretical perspective on the suitability of bimodal Floquet theory in the description of heteronuclear decoupling in solids
Authors: Garg Rajat , Ramachandran Ramesh
Published: July 2020

In this report, the suitability of bimodal Floquet theory in the description of heteronuclear decoupling experiments in solids is clarified under varied experimental conditions. Employing an operator equivalent of perturbation theory, a generalized framework for explicating the effects of multiple pulse schemes on internal spin interactions is described in the Floquet space. In contrast to in silico based methods, the analytic expressions derived from the present formalism yield faster results and offer better insights into the optimal conditions desired for maximizing the decoupling efficiency in experiments. Through appropriate examples, the validity of the approximations employed in the analytic theory is examined methodically through a comparison between analytic and numerical simulations.
A coarse-grained model of dimethyl sulfoxide for molecular dynamics simulations with lipid membranes
Authors: Shobhna  , Kumari Monika , Kashyap Hemant K.
Published: July 2020

Enhanced permeability of biomembranes upon the application of small amphiphiles is of vital importance to biologists and pharmacists, as their physiochemical interactions open new pathways for transdermal drug transportation and administration. Amphiphilic dimethyl sulfoxide (DMSO) is known to alter biomembrane permeability. Atomistic simulation-based studies to explore the impact of amphiphilic molecules on the model lipid membranes are of immense importance. These studies provide molecular details on how the membrane physical properties, such as fluidity and thickness, are modulated by amphiphile–lipid interactions. However, such approaches are usually limited to short simulation time and length scales. To circumvent such limitations, the use of coarse-grained (CG) models is a current computational strategy. In this article, we have presented a new CG force-field for DMSO for molecular dynamics (MD) simulations. The model is designed to reproduce experimental bulk properties of DMSO and its aqueous mixtures, molecular-level structure of liquid DMSO, and the phase transfer energy of a single DMSO molecule from the aqueous phase to the lipid bilayer hydrophobic interior. The current CG DMSO model successfully mimics the structural variation in phospholipid bilayer systems (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine) including alteration in bilayer thickness, lipid tail ordering, lipid lateral packing, and electron density profiles at various DMSO concentrations when compared to those obtained from parallel atomistic simulations.
The translational and rotational motions of a cylindrical particle in a granular shear flow inside a split bottom Couette cell
Authors: Tao Xingtian , Wu Huixuan
Published: July 2020

The motion of a sample particle in a Couette-cell granular flow is measured using the magnetic particle tracking technology. This technology allows simultaneous measurements of translation and rotation of an individual grain in an opaque environment. The anisotropic sample particle is a cylinder with an aspect ratio 1, and the other grains in the flow are spherical balls. The trajectory shows that the particle in the studied Couette cell with a split bottom moves in a layered structure. The orientation distribution shows that the cylindrical particle prefers to align in specific directions, even though the aspect ratio is low and the shear motion should not cause strong alignment. A symbolic-based method is used to examine the jumping between spatial layers and the flipping among preferred directions. The result shows that the duration of particle staying in a preferred state is much longer than the duration of transition. In addition, a jumping particle has a higher chance to flip. In the bulk flow, the translational energy varies significantly along the radial direction. The magnitude of translational kinetic energy is generally much larger than the rotational motion.
Transport coefficients of multi-component mixtures of noble gases based on ab initio potentials: Viscosity and thermal conductivity
Authors: Sharipov Felix , Benites Victor J.
Published: July 2020

The viscosity and thermal conductivity of binary, ternary, and quaternary mixtures of helium, neon, argon, and krypton at low density are computed for wide ranges of temperatures and molar fractions, applying the Chapman–Enskog method. Ab initio interatomic potentials are employed in order to calculate the omega-integrals. The relative numerical errors of the viscosity and thermal conductivity do not exceed 10−6 and 10−5, respectively. The relative uncertainty related to the interatomic potential is about 0.1%. A comparison of the present data with results reported in other papers available in the literature shows a significant improvement of accuracy of the transport coefficients considered here.
Type 1 conventional dendritic cells are systemically dysregulated early in pancreatic carcinogenesis
Authors: Lin Jeffrey H. , Huffman Austin P. , Wattenberg Max M. , Walter David M. , Carpenter Erica L. , Feldser David M. , Beatty Gregory L. , Furth Emma E. , Vonderheide Robert H.
Published: July 2020

Type 1 conventional dendritic cells (cDC1s) are typically thought to be dysregulated secondarily to invasive cancer. Here, we report that cDC1 dysfunction instead develops in the earliest stages of preinvasive pancreatic intraepithelial neoplasia (PanIN) in the KrasLSL-G12D/+ Trp53LSL-R172H/+ Pdx1-Cre–driven (KPC) mouse model of pancreatic cancer. cDC1 dysfunction is systemic and progressive, driven by increased apoptosis, and results in suboptimal up-regulation of T cell–polarizing cytokines during cDC1 maturation. The underlying mechanism is linked to elevated IL-6 concomitant with neoplasia. Neutralization of IL-6 in vivo ameliorates cDC1 apoptosis, rescuing cDC1 abundance in tumor-bearing mice. CD8+ T cell response to vaccination is impaired as a result of cDC1 dysregulation. Yet, combination therapy with CD40 agonist and Flt3 ligand restores cDC1 abundance to normal levels, decreases cDC1 apoptosis, and repairs cDC1 maturation to drive superior control of tumor outgrowth. Our study therefore reveals the unexpectedly early and systemic onset of cDC1 dysregulation during pancreatic carcinogenesis and suggests therapeutically tractable strategies toward cDC1 repair.
Blimp-1 is essential for allergen-induced asthma and Th2 cell development in the lung
Authors: He Kun , Hettinga Angela , Kale Sagar Laxman , Hu Sanmei , Xie Markus M. , Dent Alexander L. , Ray Anuradha , Poholek Amanda C.
Published: July 2020

A Th2 immune response is central to allergic airway inflammation, which afflicts millions worldwide. However, the mechanisms that augment GATA3 expression in an antigen-primed developing Th2 cell are not well understood. Here, we describe an unexpected role for Blimp-1, a transcriptional repressor that constrains autoimmunity, as an upstream promoter of GATA3 expression that is critical for Th2 cell development in the lung to inhaled but not systemically delivered allergens but is dispensable for TFH function and IgE production. Mechanistically, Blimp-1 acts through Bcl6, leading to increased GATA3 expression in lung Th2 cells. Surprisingly, the anti-inflammatory cytokine IL-10, but not the pro-inflammatory cytokines IL-6 or IL-21, is required via STAT3 activation to up-regulate Blimp-1 and promote Th2 cell development. These data reveal a hitherto unappreciated role for an IL-10–STAT3–Blimp-1 circuit as an initiator of an inflammatory Th2 response in the lung to allergens. Thus, Blimp-1 in a context-dependent fashion can drive inflammation by promoting rather than terminating effector T cell responses.