bluuebunny/crossref_metadata_2025 huggingface dataset:
Heck reaction prediction using a transformer model based on a transfer learning strategy
Authors: Wang Ling , Zhang Chengyun , Bai Renren , Li Jianjun , Duan Hongliang
Published: July 2020

A proof-of-concept methodology for addressing small amounts of chemical data using transfer learning is presented.
Surprisingly big linker-dependence of activity and selectivity in CO2 reduction by an iridium(i) pincer complex
Authors: Hu Gongfang , Jiang Jianbing “Jimmy” , Kelly H. Ray , Matula Adam J. , Wu Yueshen , Romano Neyen , Mercado Brandon Q. , Wang Hailiang , Batista Victor S. , Crabtree Robert H. , Brudvig Gary W.
Published: July 2020

Here, we report the quantitative electroreduction of CO2 to CO by a PNP-pincer iridium(i) complex bearing amino linkers in DMF/water. The activity and selectivity of the reduction greatly depend on the choice of linker within the ligand.
Alchemy of donor–acceptor–donor multi-photofunctional organic materials: from construction of electron-deficient azaaromatics to exploration of functions
Authors: Takeda Youhei , Data Przemyslaw , Minakata Satoshi
Published: July 2020

This Feature Article overviews the recent development of multi-photofunctional organic materials based on a twisted donor-acceptor-donor scaffold, which is driven by novel synthetic methods for exotic azaromatic compounds.
Memory devices based on novel alkyl viologen halobismuthate(iii) complexes
Authors: Dashitsyrenova Dolgor D. , Adonin Sergey A. , Gorokh Igor D. , Kraevaya Olga A. , Pavlova Alina V. , Abramov Pavel A. , Frolova Lyubov A. , Sokolov Maxim N. , Fedin Vladimir P. , Troshin Pavel A.
Published: July 2020

Four novel halobismuthate(iii) complexes with alkyl viologen cations: (R2Viol)2[Bi2X10] (R = n-butyl, n-pentyl, X = Cl, Br) have been synthesized.
Large decanuclear calcium and strontium hydride clusters
Authors: Martin Johannes , Eyselein Jonathan , Langer Jens , Elsen Holger , Harder Sjoerd
Published: July 2020

The largest, most hydride-rich, Ca10H16 cluster is formed by condensation of two smaller Ca6H9 octahedrons (the isostructural Sr hydride cluster is also reported).
The optimization effect of titanium on the phase change properties of SnSb4 thin films for phase change memory applications
Authors: Zhao Zihan , Hua Sicong , Su Xiao , Shen Bo , Song Sannian , Song Zhitang , Wu Weihua , Zhai Jiwei
Published: July 2020

Titanium-doped SnSb4 phase-change thin film has been experimentally investigated for phase-change random access memory (PCRAM) use.
Operando potassium K-edge X-ray absorption spectroscopy: investigating potassium catalysts during soot oxidation
Authors: Davies Catherine J. , Mayer Alexander , Gabb Jess , Walls Jake M. , Degirmenci Volkan , Thompson Paul B. J. , Cibin Giannantonio , Golunski Stan , Kondrat Simon A.
Published: July 2020

Operando X-ray absorption spectroscopy of potassium catalysts during soot oxidation.
Non-covalent interactions and their impact on the complexation thermodynamics of noble gases with methanol
Authors: Vieira Lúcio Renan , de Brito Sandro Francisco , Barbosa Mateus Rodrigues , Lopes Thiago Oliveira , Machado Daniel Francisco Scalabrini , de Oliveira Heibbe Cristhian B.
Published: July 2020

Accurate ab initio calculations provide the reliable information needed to study the potential energy surfaces that control the non-covalent interactions (NCIs) responsible for the formation of weak van der Waals complexes.
Spin-symmetrised structures and vibrational frequencies of iron–sulfur clusters
Authors: Cappelluti Francesco , Bencivenni Luigi , Guidoni Leonardo
Published: July 2020

The recently developed Extended Broken Symmetry technique is employed for studying a bi- and tetra-nuclear iron–sulfur cluster with respect to magnetic, structural and, most importantly, vibrational properties.
Selective cyclohexene oxidation with O2, H2O2 and tert-butyl hydroperoxide over spray-flame synthesized LaCo1−xFexO3 nanoparticles
Authors: Büker Julia , Alkan Baris , Fu Qi , Xia Wei , Schulwitz Jonas , Waffel Daniel , Falk Tobias , Schulz Christof , Wiggers Hartmut , Muhler Martin , Peng Baoxiang
Published: July 2020

A series of spray-flame made LaCo1−xFexO3 nanoparticles showed promising activity for liquid-phase cyclohexene oxidation. Various oxidizing agents, i.e., O2, H2O2 and tert-butyl hydroperoxide, led to different product selectivities.
Green oxidation of alkylaromatics using molecular oxygen over mesoporous manganese silicate catalysts
Authors: Selvaraj Manickam , Bhaumik Asim , Assiri Mohammed A. , Subrahmanyam Ch. , Ha Chang-Sik
Published: July 2020

Highly active green mesoporous MnSBA-15(4) has unprecedented catalytic activity in solvent-free benzylic oxidation of alkylaromatics with molecular oxygen, among other Mn-containing mesoporous silica catalysts.
The structure and switchable dielectric properties of a dabco complex with chromium chloride
Authors: Cizman A. , Kowalska D. , Trzebiatowska M. , Medycki W. , Krupiński M. , Staniorowski P. , Poprawski R.
Published: July 2020

We report a metal–organic material of the following formula [DabcoH22+]·CrCl3(H2O)3·2(Cl−) (DabcoH22+ = C6H14N22+, diprotonated 1,4-diazabicyclo[2.2.2]octanium).
One water to bind a chloride-chloride ion pair: isolation of discrete [Cl2(H2O)]2− in the solid state
Authors: Curnow Owen J. , Senthooran Rathiga
Published: July 2020

Calculations suggest that at least two waters are required to form a chloride–chloride ion pair. In fact, only one is required.
(−)-Epicatechin protects thoracic aortic perivascular adipose tissue from whitening in high-fat fed mice
Authors: Hid Ezequiel J. , Fischerman Laura , Piotrkowski Barbara , Litterio María C. , Fraga Cesar G. , Galleano Monica
Published: July 2020

Dietary (−)-epicatechin supplementation leads to the attenuation of the expansion and whitening of thoracic aorta perivascular adipose tissue, affording a crucial strategy to maintain a healthy vasculature.
Ecklonia radiata extract containing eckol protects neuronal cells against Aβ1–42 evoked toxicity and reduces aggregate density
Authors: Shrestha Srijan , Zhang Wei , Begbie Alexander J. , Pukala Tara L. , Smid Scott D.
Published: July 2020

Ecklonia radiata extract and phlorotannin fraction containing predominantly eckol-type phlorotannins inhibited the cytotoxicity of Aβ1–42 in neuronal PC-12 cells and evoked a reduction in the density of Aβ1–42 aggregates.
Synthesis, self-assembly, and air-stable radical anions of unconventional 6,7-bis-nitrated N-annulated perylene diimides
Authors: Cann Jonathan , Gelfand Benjamin Sidney , Welch Gregory C.
Published: July 2020

Unusual 6,7-bis-nitrated N-annulated perylene diimides are reported which have stabilized frontier molecular orbitals. The highly stabilized LUMO enables the generation of air-stable radical anions.
Novel electrocatalysts for borohydride fuel cells: enhanced power generation by optimizing anodic core–shell nanoparticles on reduced graphene oxide
Authors: Mahmoodi Raana , Chalani Mina , Hosseini Mir Ghasem , Darbandi Masih
Published: July 2020

CNi–SPdexhibits an excellent performance and rGO is a superior support compared with Vulcan and MWCNTs.
Investigation of high-performance adsorption for benzene and toluene vapors by calix[4]arene based organosilica (CBOS)
Authors: Temel Farabi , Kutluay Sinan
Published: July 2020

Calix[4]arene based organosilica (CBOS) was successfully prepared, characterized, and used for the adsorption of benzene and toluene vapors for the first time. The benzene and toluene vapor uptake of CBOS was determined to be 606 and 672 mg g−1, respectively.
An autocatalytic route of CuO/Co3O4@SiO2 nanocapsules as excellent performance supercapacitor materials
Authors: Chen Yu , Ma Qinghai , Li Zhenhui , Cui Fang , Xu Linxu , Zhang Jiajia , Chai Zhiyi , Ma Wenlu , Cui Tieyu
Published: July 2020

Nanocapsules prepared with silica as a carrier and coated with Co3O4 and CuO nanoparticles are used for high-performance supercapacitors.
Two anthracene chromophore based metal–organic frameworks for gas adsorption and promising nitro aromatic sensing
Authors: Hu Xiao-Li , Wang Kang , Li Xiao , Pan Qing-Qing , Su Zhong-Min
Published: July 2020

Two novel metal–organic frameworks (MOFs) have been synthesized under solvothermal conditions. Studies on luminescence sensing show 1 and 2 are highly selective and recyclable in the detection of nitroaromatic explosives, especially for TNP.
Correction: Synthesis, structural characterization, electrochemical behavior and anticancer activity of gold(iii) complexes of meso-1,2-di(1-naphthyl)-1,2-diaminoethane and tetraphenylporphyrin
Authors: Altaf Muhammad , Ahmad Saeed , Kawde Abdel-Nasser , Baig Nadeem , Alawad Abdullah , Altuwaijri Saleh , Stoeckli-Evans Helen , Isab Anvarhusein A.
Published: July 2020

Correction for ‘Synthesis, structural characterization, electrochemical behavior and anticancer activity of gold(iii) complexes of meso-1,2-di(1-naphthyl)-1,2-diaminoethane and tetraphenylporphyrin’ by Muhammad Altaf et al., New J. Chem., 2016, 40, 8288–8295, DOI: 10.1039/C6NJ00692B.
On the development of a nucleophilic methylthiolation methodology
Authors: Carvalho Bernardo Basbaum Portinho de Puga , Amaral Adriane Antonia Pereira , de Castro Pedro Pôssa , Ferreira Fernanda Cerqueira Moreira , Horta Bruno Araújo Cautiero , Amarante Giovanni Wilson
Published: July 2020

A novel nucleophilic methylthiolation method is described. This process allows a diversity of either conjugate additions or substitutions reactions in order to incorporate CH3S– group into activated carbons.
The curious yellow colouring matter of the Iceland poppy
Authors: Devlin Rory , Sperry Jonathan
Published: July 2020

This account provides an chronological overview of the fascinating history of the pigment responsible for the yellow colour of the Iceland poppy (Papaver nudicaule).
Controlling the reactions of 1-bromogalactose acetate in methanol using ionic liquids as co-solvents
Authors: Gilbert Alyssa , Haines Ronald S. , Harper Jason B.
Published: July 2020

Using an ionic liquid in the solvent mixture for the reaction of a galactose substrate leads to changes in both the rate constant and the products as the solvent composition changes.
Polymer compositions on kinetic resolution of secondary alcohols using polymer-supported silyl chlorides
Authors: Zhang Tian , Dickerson Shelby D. , Zhu Tianyu , Tang Chuanbing , Wiskur Sheryl L.
Published: July 2020

Modulating the polarity of the polymer backbone affects the selectivity of asymmetric silylation.
Fabrication of high performance TFN membrane containing NH2-SWCNTs via interfacial regulation
Authors: Kong Qing , Xu Hang , Liu ChenWei , Yang Guang , Ding Mingmei , Yang Wen , Lin Tao , Chen Wei , Gray Stephen , Xie Zongli
Published: July 2020

The surface properties and structures of the polyamide (PA) active layer were suitably tailored by introducing different amounts of NH2-SWCNTs into the PA layer.
Synthesis of bioactive polyaniline-b-polyacrylic acid copolymer nanofibrils as an effective antibacterial and anticancer agent in cancer therapy, especially for HT29 treatment
Authors: Bagheri Nazanin , Mansour Lakouraj Moslem , Nabavi Seyed Reza , Tashakkorian Hamed , Mohseni Mojtaba
Published: July 2020

In this work, a new highly water-soluble copolymer of polyacrylic acid with polyaniline is introduced.
Controlling crystal growth of MIL-100(Fe) on Ag nanowire surface for optimizing catalytic performance
Authors: Chen Xi , Zhang Yanshuang , Kong Xiangyun , Guo Zanru , Xu Wenyuan , Fang Zhili , Wang Shaohui , Liu Lingzhi , Liu Yongxin , Zhang Jiali
Published: July 2020

Ag/MIL-100(Fe) core/sheath nanowire with controlled crystal growth of MIL-100(Fe) on the Ag nanowire surface was prepared for optimizing catalytic performance.
New nanosized Gd–Ho–Sm doped M-type strontium hexaferrite for water treatment application: experimental and theoretical investigations
Authors: Elansary M. , Belaiche M. , Ahmani Ferdi C. , Iffer E. , Bsoul I.
Published: July 2020

Development of the new nanohexaferrite SrHo0.01Gd0.01Sm0.01Fe11.97O19 for important applications in industry, which could be very beneficial for applications in magnetic water treatment.
High pressure structural behaviour of 5,5′-bitetrazole-1,1′-diolate based energetic materials: a comparative study from first principles calculations
Authors: Moses Abraham B.
Published: July 2020

We report the high pressure structural and vibrational properties of 5,5′-bitetrazole-1,1′-diolate based energetic ionic saltsviadispersion-corrected density functional theory calculations.
A concise method for fully automated radiosyntheses of [18F]JNJ-46356479 and [18F]FITM via Cu-mediated 18F-fluorination of organoboranes
Authors: Yuan Gengyang , Shoup Timothy M. , Moon Sung-Hyun , Brownell Anna-Liisa
Published: July 2020

A modified alcohol-enhanced 18F-fluorodeboronation has been developed for the radiosyntheses of [18F]JNJ-46356479 and [18F]FITM.
Comment on “Increasing chemistry students’ knowledge, confidence, and conceptual understanding of pH using a collaborative computer pH simulation” by S. W. Watson, A. V. Dubrovskiy and M. L. Peters, Chem. Educ. Res. Pract., 2020, 21, 528
Authors: Taber Keith S.
Published: July 2020

This comment discusses some issues about the use and reporting of experimental studies in education, illustrated by a recently published study that claimed (i) that an educational innovation was effective despite outcomes not reaching statistical significance, and (ii) that this refuted the findings of an earlier study. The two key issues raised concern how the research community should understand the concept of refutation when comparing across studies, and whether the adoption of inferential statistics in a study should bind researchers to accept the inferences such tests suggest.
Observation of intensity dependent phase-separation in photoreactive monomer–nanoparticle formulations under non-uniform visible light irradiation
Authors: Pathreeker Shreyas , Chen Fu-Hao , Biria Saeid , Hosein Ian D.
Published: July 2020

Under irradiation with microscale light beams, polymer–nanoparticle formulations undergo intensity-dependent evolution into either phase separated (core–shell) or homogenous (embedded) morphologies.
Interface modulation of Mo2C@foam nickel via MoS2 quantum dots for the electrochemical oxygen evolution reaction
Authors: Lei Lei , Huang Danlian , Lai Cui , Zhang Chen , Deng Rui , Chen Yashi , Chen Sha , Wang Wenjun
Published: July 2020

The MoS2 QDs confined in Mo2C established a significant link between the electronic manipulation and activities of Mo2C.
Chain-like uranyl-coordination polymer as a bright green light emitter for sensing and sunlight driven photocatalysis
Authors: Gomez G. E. , Onna D. , D'vries R. F. , Barja B. C. , Ellena J. , Narda G. E. , Soler-Illia G. J. A. A.
Published: July 2020

Synopsis: A new mixed uranyl-coordination polymer (UCP) was obtained and applied as a strong potential green solid-state light emitter for chemical sensing and as a photocatalyst platform.
The Effectiveness of Hybrid Telepractice and In-Person Fluency Treatment for a School-Aged Child: A Case Study
Authors: Ryer Jacqueline E. , Poll Gerard H.
Published: July 2020

Purpose

This case study assessed the effects of hybrid telepractice and in-person delivery of the Smooth Speech Treatment (Craig, 2010) for a school-aged child who stutters.

Method

The participant was an 8-year-old child who stuttered. Telepractice or in-person delivery were randomly assigned to treatment sessions in a single-subject AB design. The primary outcome measures were the percentage of syllables stuttered in conversation and reading probes taken at the beginning and end of each treatment session. Communication attitudes were measured before treatment began and at a posttreatment maintenance session. The pattern of treatment gains by delivery platform was also evaluated.

Results

Visual inspection of trends for outcome measures supported an association between the overall treatment package and a reduction in syllables stuttered. Pre- to post- treatment measures indicated an improvement in the child's attitudes toward stuttering. Within-session gains for telepractice sessions were more variable than in-person sessions.

Conclusions

These results indicate that fluency treatment delivered using a blend of telepractice and in-person delivery can be effective for a school-aged child who stutters. The findings align with prior studies showing the effectiveness of telepractice-delivered treatment for preschool children and adolescents. Replications of these results are needed with additional school-aged participants. Additional research is also warranted on factors that contribute to the variability of telepractice treatment effects for school-aged children.
Impacts of three‐phase power converter operating modes on harmonic emissions in distribution networks: harmonics emission within 2–9 kHz
Authors: Yaghoobi Jalil , Zare Firuz
Published: July 2020

The increasing penetration level of power electronic converters in distribution networks has raised concerns about the impact of these converters on the power quality of the grid. Pulse‐width modulated (PWM) voltage generated by these converters creates higher frequency current distortion around both its switching frequency and multiples, which could be circulated through the grid. Consequently, it is essential to understand and analyse the frequencies and amplitudes of these harmonics in terms of load parameters. Thus, this study proposes an analytical method to find the inverter current harmonics generated by PWM signal in terms of the load parameters, including its power factor. The impact of the load power factor on the inverter current harmonics has been found to be significant using the derived equations. Simulation and practical results have confirmed the accuracy of the obtained equations to calculate the inverter current harmonics. The mathematical modelling is important for harmonic analysis of converter within 2–9 kHz range as a new standard has been developed by IEC SC77A, WG1 committee.
Novel distortionless dimming in high power LED lighting using isolated SEPIC converter
Authors: Pal Somnath , Singh Bhim , Shrivastava Ashish
Published: July 2020

A new low‐cost energy‐saving concept in the modern light‐emitting diode (LED) illumination system is developed and implemented using an isolated single‐ended primary inductance converter (SEPIC). The dimming scheme presented in this study is a single‐step with negligible distortion in the AC mains current as compared to the traditional low‐cost triode for alternating current (TRIAC) dimming system, which distorts the AC mains current wave‐shape beyond sinusoidal nature due to the phase‐cut techniques. This dimming concept is completely retrofitted, no additional arrangement is required to initiate the dimming as compared to a TRIAC dimmer or other controllers. The isolated SEPIC converter is modelled and analysed in detail using the state‐space average technique. The stability of the designed converter and overall closed‐loop control are verified using Bode‐plot analysis. The full load converter efficiency is found around 93%, which is much higher than the conventional flyback topology‐based LED driver. The concept presented in this study is tested with the help of a laboratory prototype with an LED load of 60 W.
Grid cell field reconstruction based on rat hippocampal cognitive mechanism and hebbian plasticity
Authors: Yu Naigong , Zhai Yujia
Published: July 2020

The grid cells have obvious spatial firing characteristics and can form a hexagonal grid firing structure. It uses its own motion information to encode space, and forms a stable grid structure by integrating paths. Grid cells are an important part of spatial expression. Through spatial expression, mammals can find their way. Given a starting and ending point, many animals are able to navigate autonomously without training, finding a target point, and showing that the hippocampus plays a role. In the process of exploring the environment of rats, footprints will spread all over the environment, and grid cell field will be generated. However, due to errors in velocity estimation and inherent noise in neural calculation, the continuous accumulation of errors will lead to the instability of grid cell field. The authors use the plasticity of Hebbian to reconstruct the grid field, enhance the stability of the grid cell field, so that mammals can locate and navigate more accurately in complex or dynamic environments.
Method of social network analysis and visualisation based on reviews
Authors: Xu Xiaowei , Liu Wei , Tao Ye , Wang Xiaodong , Wu Jilong
Published: July 2020

With the development of e‐commerce platforms, the huge amount of transaction volume produces a lot of commentary information. To study the relationship between users and user comments and corresponding products, a social network analysis method based on user comments is proposed. The authors regard the network connection between goods and user comments as a problem on the network and use the spectral clustering algorithm to maintain the structural characteristics of the network. This method can visualise the network structure features such as user clustering and distribution, which can help to understand the network from a macro perspective and be directly applied to the visualisation of other comment‐based networks. It is significant for analysing the relationship between users and user comments and corresponding products. The comparative visualisation experiments are also discussed, to validate the effectiveness of the proposed method.
NH3 (1,1) hyperfine intensity anomalies in the Orion A molecular cloud
Authors: Zhou Dong-dong , Wu Gang , Esimbek Jarken , Henkel Christian , Zhou Jian-jun , Li Da-lei , Ji Wei-guang , Zheng Xing-wu
Published: July 2020

Ammonia (NH3) inversion lines, with their numerous hyperfine components, are a common tracer used in studies of molecular clouds (MCs). In local thermodynamical equilibrium, the two inner satellite lines (ISLs) and the two outer satellite lines (OSLs) of the NH3(J, K) = (1,1) transition are each predicted to have equal intensities. However, hyperfine intensity anomalies (HIAs) are observed to be omnipresent in star formation regions, a characteristic which is still not fully understood. In addressing this issue, we find that the computation method of the HIA by the ratio of the peak intensities may have defects, especially when used to process the spectra with low-velocity dispersions. Therefore, we defined the integrated HIAs of the ISLs (HIAIS) and OSLs (HIAOS) by the ratio of their redshifted to blueshifted integrated intensities (unity implies no anomaly) and developed a procedure to calculate them. Based on this procedure, we present a systematic study of the integrated HIAs in the northern part of the Orion A MC. We find that integrated HIAIS and HIAOS are commonly present in the Orion A MC and no clear distinction is found at different locations of the MC. The medians of the integrated HIAIS and HIAOS are 0.921 ± 0.003 and 1.422 ± 0.009, respectively, which is consistent with the HIA core model and inconsistent with the collapse or expansion (CE) model. In the selection of those 170 positions, where both integrated HIAs deviate by more than 3σ from unity, most (166) are characterized by HIAIS < 1 and HIAOS > 1, which suggests that the HIA core model plays a more significant role than the CE model. The remaining four positions are consistent with the CE model. We compare the integrated HIAs with the para-NH3 column density (N(para-NH3)), kinetic temperature (TK), total velocity dispersion (σv), non-thermal velocity dispersion (σNT), and the total opacity of the NH3(J, K) = (1,1) line (τ0). The integrated HIAIS and HIAOS are almost independent of N(para-NH3). The integrated HIAIS decreases slightly from unity (no anomaly) to about 0.7 with increasing TK, σv, and σNT. The integrated HIAOS is independent of TK and reaches values close to unity with increasing σv and σNT. The integrated HIAIS is almost independent of τ0, while the integrated HIAOS rises with τ0, thus showing higher anomalies. These correlations cannot be fully explained by either the HIA core nor the CE model.
Idiopathische inflammatorische Myopathien
Authors: Tomaras Stylianos , Kekow Jörn , Feist Eugen
Published: July 2020

Myositis is a rare and an extremely heterogeneous autoimmune disease, that causes muscle weakness. Currently, “idiopathic inflammatory myopathies (IIM)“ is the preferred umbrella-term used to describe the disease complexity within individuals. IIM include dermatomyositis, polymyositis, inclusion body myositis, autoimmune necrotizing myopathy, overlap myositis and antisynthetase syndrome. Research activity concerning myositis was very intense over the past ten years and led to new diagnostic approach as well as to novel therapeutic strategies. Correct classification is the key for successful management. One single treatment regime for every possible organ involvement in all different forms of IIM is still not existing.
Evaluating the Effect of Pravastatin in Early-Onset Fetal Growth Restriction: A Nonrandomized and Historically Controlled Pilot Study
Authors: Carreras Elena , Alijotas-Reig Jaume , Mendoza Manel , Ferrer-Oliveras Raquel , Bonacina Erika , Garcia-Manau Pablo , Rodo Carlota
Published: July 2020

Objective This study aimed to analyze the effect of pravastatin on angiogenic factors, feto–maternal Doppler findings and pregnancy outcomes in women with early-onset fetal growth restriction (FGR) treated with pravastatin compared with nontreated controls.

Study Design This was a pilot study conducted between March 2016 and September 2017. Women with single pregnancies and FGR diagnosed at ≤ 28 weeks of gestation were offered 40 mg of pravastatin daily. Doppler progression, soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) values, and pregnancy outcomes were assessed and compared with consecutive historical controls. Controls were matched to treated women for gestational age, maternal characteristics, maternal and obstetric history, Doppler severity classification, and angiogenic factors at diagnosis. The sFlt-1/PlGF was measured in maternal serum at two different times: before pravastatin was started (ratio M0) and during pravastatin treatment (ratio M1). Doppler severity was classified into four categories: normal, mild, moderate, and severe.

Results A total of 38 women were enrolled in this study. No differences were observed in baseline characteristics between groups. However, when compared with the ratio M0, M1 was increased by a median (interquartile range) of 67.0 (−34.8 to 197.3) in the control group but decreased by a median (interquartile range) of −10.1 (−53.1 to −0.07) in the pravastatin treated group (p < 0.001). No significant differences were observed in Doppler progression throughout pregnancy. Median interval from diagnosis to delivery was extended by 16.5 days, the median newborn birthweight was increased from 1,040 to 1,300 g, and the number of women with preeclampsia decreased from 9 (47.4%) to 6 (31.6%) in treated women; however, these trends were not statistically significant.

Conclusion In women with early-onset FGR, treatment with pravastatin 40 mg daily was associated with significant improvement in the angiogenic profile. Additionally, median pregnancy duration and median birthweight increased and the incidence of PE was reduced in treated women. Nevertheless, since this pilot study was underpowered, none of these differences were statistically significant.

Key Points
Detection of COVID-19 in a Vulvar Lesion
Authors: Sansone Stephanie A. , Rubin Elizabeth S. , Hirshberg Adi , Clement Elizabeth G. , Srinivas Sindhu K.
Published: July 2020

As new information about coronavirus disease 2019 (COVID-19) is rapidly discovered, clinicians are better equipped to make informed decisions for their patients. While current research suggests COVID-19 viral antigen is not found in vaginal secretions, its detectability in the female lower genital tract may have clinical implications for obstetric and gynecologic care for women. We present a case of a woman at 31 weeks' gestation with simultaneous upper respiratory symptoms and vulvovaginitis. She was found to have a vulvar lesion positive for severe acute respiratory syndrome-COVID by viral swab. This case shows that COVID-19 is detectable in the vulva. This may have implications for health care workers' exposure and personal protective equipment needs. While vertical transmission has largely not been reported, the presence of detectable virus in the female lower genital tract makes this a continued possibility and area of study.

Key Points
Cost-Utility of Sildenafil for Persistent Pulmonary Hypertension of the Newborn
Authors: Evers Patrick D. , Critser Paul J. , Cash Michelle , Magness Melissa , Hoelle Susan , Hirsch Russel
Published: July 2020

Objective While advanced therapies for severe persistent pulmonary hypertension of the newborn (PPHN) such as inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO) are standard treatments in high-income countries, these therapies are often unavailable in resource-limited settings such as middle-income countries. However, there are small clinical trials illustrating the efficacy of sildenafil at reducing mortality in PPHN. This analysis sought to determine the cost-utility of enteral sildenafil for the treatment of severe PPHN.

Study Design A Markov-state transition model was constructed for the two clinical approaches to compare costs, clinical outcomes, and quality of life: (1) “conventional,” (2) “sildenafil.” The impact of sildenafil was modeled as a relative risk modifier of the conventional strategy's mortality risk. Transitional probabilities, costs, and utility metrics were extracted from the literature. Sensitivity analyses for each model input as well as 100-patient Monte Carlo simulations were used to test the durability of the model conclusion.

Results The sildenafil strategy was cost-effective for upper but not lower middle-income countries with an incremental cost-effectiveness ratio of $2,339 per quality-adjusted life year. This conclusion was durable across a wide-range of model assumptions; the sildenafil strategy only failed to meet criteria for cost-effectiveness when sildenafil therapy had a mortality relative risk efficacy of >0.89, if life expectancy in that country is <40 years, or if the lifetime forecasted costs of a survivor's life was quite high.

Conclusion Enteral sildenafil is a cost-effective intervention for severe PPHN for upper middle-income countries where ECMO and iNO are not available.

Key Points
Entropy dimension of shift spaces on monoids
Authors: Ban Jung-Chao , Chang Chih-Hung , Huang Nai-Zhu
Published: July 2020

We consider the entropy dimension of G-shifts of finite type for the case where G is a non-Abelian monoid. Entropy dimension tells us whether a shift space has zero topological entropy. Suppose the Cayley graph CG of G has a finite representation (that is, {CgG : g ∈ G} is a finite set up to graph isomorphism), and relations among generators of G are determined by a matrix A. We reveal an association between the characteristic polynomial of A and the finite representation of the Cayley graph. After introducing an algorithm for the computation of the entropy dimension, the set of entropy dimensions is related to a collection of matrices in which the sum of each row of every matrix is bounded by the number of leaves of the graph. Furthermore, the algorithm extends to G having finitely many free-followers.
Introduction of multi-particle Büttiker probes—Bridging the gap between drift diffusion and quantum transport
Authors: Wang Kuang-Chung , Grassi Roberto , Chu Yuanchen , Hari Sureshbabu Shree , Geng Junzhe , Sarangapani Prasad , Guo Xinchen , Townsend Mark , Kubis Tillmann
Published: July 2020

State-of-the-art industrial semiconductor device modeling is based on highly efficient Drift-Diffusion (DD) models that include some quantum corrections for nanodevices. In contrast, latest academic quantum transport models are based on the non-equilibrium Green’s function (NEGF) method that covers all coherent and incoherent quantum effects consistently. Carrier recombination and generation in optoelectronic nanodevices represent an immense numerical challenge when solved within NEGF. In this work, the numerically efficient Büttiker-probe model is expanded to include electron–hole recombination and generation in the NEGF framework. Benchmarks of the new multiple-particle Büttiker probe method against state-of-the-art quantum-corrected DD models show quantitative agreements except in cases of pronounced tunneling and interference effects.
Design and development of portable handheld multimodal spectroscopic probe system for skin tissue analysis
Authors: Babu Shinto , Vengalathunadakal K. Shinoj , Nair Saritha K.
Published: July 2020

The potential of optical spectroscopic techniques such as diffused reflectance and fluorescence as non-invasive, in vivo diagnostic tools is being explored and validated recently. In this paper, we present the design and development of a handheld, portable, multimodal fiber optic based probe scheme to sequentially measure diffuse reflectance and fluorescence. The proposed prototype is designed to sequentially acquire diffused reflectance in the broad wavelength range of 400 nm–1600 nm and fluorescence using custom-chosen spectrophotometers, monochromatic and broadband light sources, fibers to accommodate a wide wavelength range, custom-built probe distal end, and a real-time spectral stitching and display unit. The prototype is characterized using in-house fabricated phantom tissue samples with tunable optical properties such as scattering and absorption. The depth profile study is carried out using phantom tissue layers of known optical parameters followed by the sequential measurement of diffused reflectance and fluorescence from the tissue mimicking sample.
Performance optimization of test facility for coaxial transmission line components based on traveling wave resonator
Authors: Jha Akhil , Harikrishna J. V. S. , Palliwar Ajesh , Patel Manoj , Anand Rohit , Dalicha Hrushikesh , Vasava Paresh , Rajnish Kumar , Trivedi Rajesh , Mukherjee Aparajita
Published: July 2020

As part of development program for a high power co-axial transmission line component test facility, an existing traveling wave resonator based test stand is modified to improve power gain and ring return loss. The 10 dB directional coupler in the earlier test stand is replaced with a 14 dB directional coupler to couple radio frequency power with the ring. To achieve an improved isolation and return loss, the 14 dB directional coupler design is equipped with two broadside strip-lines with a tunable gap between them. Detailed design and optimization of the 14 dB directional coupler with and without the traveling wave resonator setup is performed using a high frequency simulator Computer Simulation Technology Microwave Studio. The low power test of the fabricated directional coupler is performed at several tuning positions to achieve an optimum operating frequency for the traveling wave resonator. Furthermore, after optimization, the maximum power gain of around 18 dB and minimum return loss of about −22 dB inside the ring are obtained. Finally, a preliminary study of the future 3 MW test facility is discussed.
Optimization of discharge antenna turn and modulation of EEPFs and plasma parameters in dual-frequency cylindrical ICP source at different gas pressures
Authors: Hua Yue , Hao Zeyu , Ren Chunsheng , Song Jian
Published: July 2020

This paper deals with the optimization of the number of discharge antenna turns N, mainly including the effect of N on the plasma parameters [plasma density ne, effective electron temperature Teff, plasma potential Vp, power transfer efficiency η, and electron energy probability function (EEPF)] in cylindrical inductively coupled plasma (ICP) source, and compares axial and radial distribution of ne with different antenna arrangement topologies, mainly referring to the non-interleaved and interleaved antenna arrangement in cylindrical dual-frequency (DF) ICPs. It is found that the cylindrical DF-ICPs with interleaved antenna arrangement can produce a higher ne due to the superposition effect of the high-frequency (HF) and low-frequency (LF) discharge region. Furthermore, based on the above optimized parameters, an optimized cylindrical DF-ICP with an interleaved antenna arrangement is employed, and the modulations of EEPFs and plasma parameters (ne, Teff, and Vp) in the case of (1) fixed HF power and varying additional LF power and (2) fixed LF power and varying additional HF power correspondingly are investigated and compared at different gas pressures of 1, 15, and 60 mTorr systematically. With the wide gas pressure range from 1 to 60 mTorr considered in a combination with two discharge frequencies of 2 and 13.56 MHz, the DF discharge covers discharge maintenance under different conditions with respect to electron heating mechanisms, e.g., collision-less and collision heating. This is a relatively comprehensive work about cylindrical DF-ICPs, which will provide some insights into the design and plasma parameters modulation of cylindrical DF-ICPs.
Accurate calculation of multipole polarizabilities for one-electron atom in Debye plasmas
Authors: Zhu Lin , He Yu Ying , Jiao Li Guang , Wang Yuan Cheng , Ho Yew Kam
Published: July 2020

The electric multipole polarizabilities of one-electron atoms embedded in weakly coupled Debye plasmas are calculated in the non-relativistic framework. The static dipole, quadrupole, octopole, and hexadecapole polarizabilities for hydrogen atoms in both ground and excited states at a variety of Debye screening parameters are calculated in high precision based on the sum-over-states method, where the system bound and continuum states are produced by employing the generalized pseudospectral method. It is shown that the contribution of bound states to the polarizability decreases with increasing the plasma screening strength, whereas the contribution of continuum states is enhanced. At very small screening parameters where the plasma environment starts to take effect, it is found that the 2l-pole polarizability for s-wave states with principle quantum number n≥l+1 has an abrupt change from its non-screening value to infinity. We attribute such a phenomenon to the sudden non-degeneracy of different angular momentum states in the n shell. With continuously increasing the screening strength, the polarizabilities for n≥l+1 states decrease to certain values and, eventually, they approach to infinity at the critical screening parameter. For states with n≤l, the 2l-pole polarizabilities show regular enhancement from the non-screening value to infinity. The present results are compared with other theoretical calculations available in the literature and it is shown that our work has established by now the most accurate predictions of multipole oscillator strengths and polarizabilities for one-electron atoms in Debye plasmas.
Behavior of particle swarms at low and moderate Reynolds numbers using computational fluid dynamics—Discrete element model
Authors: Ayeni Oladapo , Tiwari Shashank S. , Wu Chunliang , Joshi Jyeshtharaj B. , Nandakumar Krishnaswamy
Published: July 2020

In the present study, the sedimentation of a swarm of mono-sized particles is investigated using the Computational Fluid Dynamics–Discrete Element Model (CFD-DEM) approach. The computational approach employed was able to accurately predict the breakup pattern of the swarm of particles into secondary clusters. The rate of leakage of the particles from the cluster (in the creeping flow regime) was found to linearly increase with an increase in the initial number of particles present in the sedimenting cluster. The breakup pattern of the cluster of particles was found to be highly sensitive to the shape of the outer domain. At Rec = 5, the sedimentation of the cluster in a cylindrical outer domain was observed to break up into six secondary blobs (k = 6), whereas for a square and a rectangular outer domain, the breakup resulted in four (k = 4) and two (k = 2) secondary blobs, respectively. Besides, the CFD-DEM approach was found to be in excellent agreement with the experimental data as opposed to the Oseenlet point particle approach, which could not accurately predict the settling velocities for a sedimenting cluster at a finite Rec and high solid fraction (Rec = 14, ϕs ≈ 0.5).
Effective component extraction for hydraulic pump pressure signal based on fast empirical mode decomposition and relative entropy
Authors: Wang Yangding , Zhu Yong , Wang Quanlin , Yuan Shouqi , Tang Shengnan , Zheng Zhijian
Published: July 2020

As the core power source of the hydraulic transmission system, hydraulic pump has been widely used in various industrial machinery and national defense equipment. It is of great significance to explore the monitoring of the health status of the hydraulic pump. It is also necessary to extract the effective components in condition monitoring of the hydraulic pump. In this work, based on fast empirical mode decomposition (FEMD) and relative entropy, a novel method is proposed for extracting the effective components of the signal. The original signal can be automatically separated by FEMD, and the useful components of the signal can be obtained via the measurement of relative entropy. Through the validation of the numerical experiment and measured data, the results indicate that the method presents good ability in the useful component extraction for signals with multi-frequency vibration. It provides an effective solution for the reduction of the interference of useless signals, including the direct current component and noise. The desired useful signals are also accurately reconstructed.
Host–parasite coevolution: Role of selection, mutation, and asexual reproduction on evolvability
Authors: Priya Madhu , Jaiswal Prabhat K. , Shrimali Manish Dev
Published: July 2020

The key to the survival of a species lies in understanding its evolution in an ever-changing environment. We report a theoretical model that integrates frequency-dependent selection, mutation, and asexual reproduction for understanding the biological evolution of a host species in the presence of parasites. We study the host–parasite coevolution in a one-dimensional genotypic space by considering a dynamic and heterogeneous environment modeled using a fitness landscape. It is observed that the presence of parasites facilitates a faster evolution of the host population toward its fitness maximum. We also find that the time required to reach the maximum fitness (optimization time) decreases with increased infection from the parasites. However, the overall fitness of the host population declines due to the parasitic infection. In the limit where parasites are considered to evolve much faster than the hosts, the optimization time reduces even further. Our findings indicate that parasites can play a crucial role in the survival of its host in a rapidly changing environment.
Interaction of hydrogen with actinide dioxide (011) surfaces
Authors: Pegg James T. , Shields Ashley E. , Storr Mark T. , Scanlon David O. , de Leeuw Nora H.
Published: July 2020

The corrosion and oxidation of actinide metals, leading to the formation of metal-oxide surface layers with the catalytic evolution of hydrogen, impacts the management of nuclear materials. Here, the interaction of hydrogen with actinide dioxide (AnO2, An = U, Np, or Pu) (011) surfaces by Hubbard corrected density functional theory (PBEsol+U) has been studied, including spin–orbit interactions and non-collinear 3k anti-ferromagnetic behavior. The actinide dioxides crystalize in the fluorite-type structure, and although the (111) surface dominates the crystal morphology, the (011) surface energetics may lead to more significant interaction with hydrogen. The dissociative adsorption of hydrogen on the UO2 (0.44 eV), NpO2 (−0.47 eV), and PuO2 (−1.71 eV) (011) surfaces has been calculated. It is found that hydrogen dissociates on the PuO2 (011) surface; however, UO2 (011) and NpO2 (011) surfaces are relatively inert. Recombination of hydrogen ions is likely to occur on the UO2 (011) and NpO2 (011) surfaces, whereas hydroxide formation is shown to occur on the PuO2 (011) surface, which distorts the surface structure.
Two-equation and multi-fluid turbulence models for Richtmyer–Meshkov mixing
Authors: Kokkinakis Ioannis W. , Drikakis Dimitris , Youngs David L.
Published: July 2020

This paper concerns an investigation of two different approaches in modeling the turbulent mixing induced by the Richtmyer–Meshkov instability (RMI): A two-equation K-L multi-component Reynolds-averaged Navier–Stokes model and a two-fluid model. We have improved the accuracy of the K-L model by implementing new modifications, including a realizability condition for the Reynolds stress tensor and a threshold in the production of the turbulence kinetic energy. We examine the models in the one-dimensional (1D) form in the (re)-shocked mixing of a double-planar air and sulfur-hexafluoride (SF6) interface of the Atwood number |At| ≃ 0.6853. Furthermore, we investigated the models’ accuracy to RMI-induced mixing of a (re)-shocked planar-inverse chevron air–SF6 interface. Relevant integral quantities in time, as well as instantaneous profiles and contour plots, are used to assess the models’ accuracy against high-resolution implicit large eddy simulations. The proposed modifications improve the efficiency of the K-L model. The model is designed as a simple model capable of capturing the self-similar growth of Rayleigh–Taylor and Richtmyer–Meshkov flows. The two-fluid model remains more accurate but is also computationally more expensive.
Influence of glow discharge on evolution of disturbance in a hypersonic boundary layer: The effect of second mode
Authors: Zhang Yunchi , Li Chi , Lee Cunbiao
Published: July 2020

This is the companion volume on the effects of artificial disturbance on the transition process of a boundary layer over a flat plate. The artificial disturbance with the frequency in the range of second-mode instability is introduced into the boundary layer by glowing discharge on the surface of the plate. Experiments are performed using Rayleigh-scattering visualization, wall pressure pulsations measurement, and high-frequency schlieren visualization in the Φ300 mm hypersonic quiet wind tunnel at Peking University. It is found that the second-mode instability waves are stimulated remarkably by the artificial disturbance, and the boundary layer transition is triggered effectively. The second-mode instability interacts with the first mode via a phase-lock mechanism, which leads to the rapid amplification of the first mode and the moving forward of transition location.
A cryogenic magneto-optical device for long wavelength radiation
Authors: Rezvani S. J. , Di Gioacchino D. , Tofani S. , D’Arco A. , Ligi C. , Lupi S. , Gatti C. , Cestelli Guidi M. , Marcelli A.
Published: July 2020

We present here a small-scale liquid helium immersion cryostat with an innovative optical setup suitable to work in long wavelength radiation ranges and under an applied magnetic field. The cryostat is a multi-stage device with several shielding in addition to several optical stages. The system has been designed with an external liquid nitrogen boiler to reduce liquid bubbling. The optical and mechanical properties of the optical elements were calculated and optimized for the designed configuration, while the optical layout has been simulated and optimized among different configurations based on the geometry of the device. The final design has been optimized for low-noise radiation measurements of proximity junction arrays under an applied magnetic field in the wavelength range λ = 250 μm–2500 μm.