bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Global Spray Combustion Characteristics and Local Shot-to-Shot Variations in a Reacting N-Heptane Spray
Authors: Reggeti Shawn , Parker Allen , Wanstall C. Taber , Agrawal Ajay , Bittle Joshua
Published: December 2020

In support of efforts to develop improved models of turbulent spray behavior and combustion in diesel engines, experimental data and analysis must be obtained to guide and validate them. For RANS-based CFD modeling approaches it is important to have representative ensemble average experimental results. For models that provide high fidelity local details such as LES-based CFD simulations, it is desirable to have precise individual experiment results. Making comparisons however is a challenge as it is impossible to directly compare local parameters between a given experiment and LES simulation.

An optically accessible constant pressure flow rig (CPFR) is utilized to capture injection and reaction behavior with three optical diagnostic techniques: rainbow schlieren deflectometry (RSD), OH* chemiluminescence (OH*), and two-color pyrometry (2CP). The benefit of these high-speed, simultaneous diagnostics is that local measurements can be made for every stage of a single injection event, observing both how much injections differ one from another, and also how such differences evolve temporally. The CPFR allows a sufficiently large number of repeated injection experiments to be performed for proper statistical analysis and ensemble convergence, while maintaining highly repeatable, nominally constant test conditions. Even given such stable conditions however, variations in local turbulent fuel-air mixing introduce a degree of variability which may manifest as significant differences in OH* and 2CP results. A statistical method is utilized to analyze the extent of this variability, and to identify superlative injections within the data set for discussion and analysis of shot-to-shot variation.

Experimental measurements of characteristic parameters including liquid and vapor jet penetration, lift-off length, soot temperature and concentration, and turbulent flame speed, along with the shot-to-shot variability of each, are presented and discussed. While the results shown here can only postulate about the causation, the framework to characterize shot-to-shot variations could be leveraged to enable direct comparison with high-fidelity simulations without the need for averaging multiple realizations.
Effect of Discharge Energy Distribution on Flame Kernel Development
Authors: Zhu Hua , Yu Xiao , Wang Linyan , Zheng Ming , Li Liguang , Liu Mengzhu
Published: December 2020

The early flame kernel initiation and development are essential to a successful combustion process, especially under lean burn/EGR diluted conditions. Multiple ignition sites strategy has shown promise to secure the flame kernel initiation under extreme engine operating conditions. Two factors are considered to contribute to the enhanced ignition capability, i.e. the higher ignition energy and the multiple initial flame kernels. However, the mechanism why the multiple ignition sites help combustion is less understood. In this work, the impacts of the ignition energy distribution strategy on the flame inception process are investigated in a constant volume combustion chamber. A multi-coil ignition system, along with a sparkplug with three high-voltage electrodes, is used to adjust the discharge energy from 10 mJ to 240 mJ, as well as the energy deposition strategies. Experimental results have shown that the distributed energy strategy with sufficient discharge energy can establish a bigger initial flame kernel, leading to faster flame growth rates, as compared to the concentrated energy strategy.
Study on Automatic Adaptation for a Control-Oriented Model of an Advanced Diesel Engine
Authors: Nishii S. , Yamasaki Y.
Published: December 2020

Although many studies have been carried out using control-oriented engine models for advanced combustion technologies, methods of adapting model parameters for these models have still not been considerably studied. In this paper, we propose a method to adapt model parameters for an ignition model and a combustion model of a physics-based discrete diesel engine model using neural networks. Using experimental data on an engine bench as well, we examined how to perform adapting and training, such as optimization algorithms, how to select training data, appropriate feature values, and algorithms for switching the neural networks according to the operating regions. As a result, this adaptation method was able to improve the prediction accuracy of the heat release rate of pre-combustion better than when adapted using the previous adaptation method and when the model parameters were fixed.
Method for Estimating Compression Ratio and Heat Transfer Multiplier Using GT-Power and Experimental Pressure Traces
Authors: Klingbeil Adam , Lavertu Thomas
Published: December 2020

Crank-angle resolved cylinder pressure data is valuable for characterizing engine performance and various techniques have been developed for post-processing the pressure traces to understand the rate of heat release and its overall impact on engine performance. However, many of these techniques rely on accurate knowledge of the compression ratio, which may not be well-known because of uncertainties in component dimensions for new and rebuilt engines. Additionally, uncertainties in cylinder pressure referencing and top dead center (TDC) offset can lead to variation in the calculation of these parameters.

A method was developed to estimate the compression ratio and heat transfer sensitivity for large bore diesel engines using GT-Power and experimental cylinder pressure traces. An injector cutout method was used on a 228.6mm bore 16-cylinder engine to record motoring cylinder pressure traces for an individual cylinder. The cylinder pressure traces were pegged thermodynamically by matching the slope of a 40-deg window of the compression trace with that of a GT-power simulation of a similar condition. Once the cylinder pressure was properly referenced, it was found that the compression ratio of the cylinder could be estimated by matching the slope of the compression trace over a larger crank angle window. Additionally, it is shown that the location of peak cylinder pressure is dependent on heat transfer and if the location of peak cylinder pressure relative to top dead center is accurately known, then the heat transfer coefficients in GT-Power can be estimated.

For an engine where the exact compression ratio may not be known due to variations in hardware dimensions (for both new and rebuilt engines), this method provides a simple path to estimating compression ratio. Furthermore, by measuring the exact location of TDC and comparing that to the location of peak cylinder pressure, heat transfer can be estimated.
Combustion and Emission Characteristics of a Diesel Engine Working With Diesel/Jojoba Biodiesel/Higher Alcohol Blends
Authors: EL-Seesy Ahmed I. , Nour Mohamed , Xuan Tiemin , He Zhixia , Hassan Hamdy
Published: December 2020

The main concerns of utilizing jojoba biodiesel in CI engines is that it has a high viscosity and high NOx formation. Therefore, this article purposes in endeavoring to improve the combustion and emission parameters of a CI engine working with diesel/jojoba biodiesel blend and higher alcohols under various engine loads. The higher alcohols typically are n-butanol, n-heptanol, and n-octanol, which are combined with 50% diesel, 40% of jojoba biodiesel at a volume portion of 10%, and they are designated as DJB, DJH, and DJO respectively. The jojoba biodiesel is manufactured via a transesterification process with facilitating mechanical dispersion. The findings display that there is a drop in pmax and HRR for DJB, DJH, and DJO blends compared to pure diesel fuel, whereas the combustion duration and ignition delay are extended. The brake specific fuel consumption is enlarged. Concerning engine emissions, the NOx formation is reduced while the CO, UHC, and soot emissions are increased for DJB, DJH, and DJO mixtures. It can be deduced that combining high fractions of jojoba biodiesel with C4, C7, and C8 alcohols have the feasible to accomplish low NOx formation in the interim having high thermal efficiency level.
Assessment of Spark, Corona, and Plasma Ignition Systems for Gasoline Combustion
Authors: Biswas Sayan , Ekoto Isaac , Singleton Dan , Mixell Kristapher , Ford Patrick
Published: December 2020

In the present study, the performance and emissions characteristics of three low-temperature plasma (LTP) ignition systems were compared to a more conventional strategy that utilized a high-energy coil (93 mJ) inductive spark igniter. All experiments were performed in a single-cylinder, optically accessible, research engine. In total, three different ignition systems were evaluated: (1) an Advanced Corona Ignition System (ACIS) that used radiofrequency (RF) discharges (0.5–2.0 ms) to create corona streamer emission into the bulk gas via four-prong electrodes, (2) a Barrier Discharge Igniter (BDI) that used the same RF discharge waveform to produce surface LTP along an electrode encapsulated completely by the insulator, and (3) a Nanosecond Repetitive Pulse Discharge (NRPD) ignition system that used a non-resistor spark plug and positive DC pulses (∼10 nanoseconds width) for a fixed frequency of 100 kHz, with the operating voltage-controlled to avoid LTP transition to breakdown. For the LTP ignition systems, pulse energy and duration (or number) were varied to optimize efficiency. A single 1300 revolutions per minute (rpm), 3.5 bar indicated mean effective pressure (IMEP) homogeneous operating point was evaluated. Equivalence ratio (ϕ) sweeps were performed that started at stoichiometric conditions and progressed toward the lean limit.

Both the ACIS and NRPD ignition systems extended the lean limit (where the variation of IMEP < 3%) limit (ϕ = 0.65) compared to the inductive spark (ϕ = 0.73). The improvement was attributed to two related factors. For the ACIS, less spark retard was required as compared to spark ignition due to larger initial kernel volumes produced by four distinct plasma streamers that emanate into the bulk gas. For the NRPD ignition system, additional pulses were thought to add expansion energy to the initial kernel. As a result, initial flame propagation was accelerated, which accordingly shortens early burn rates.
Accessing social service support: Barriers experienced by Chinese migrants living in Auckland, Aotearoa New Zealand
Authors: Kan King Lok , Connor Helene , Beddoe Liz
Published: December 2020

INTRODUCTION: According to Census 2013, approximately 25% of Auckland’s population is Asian, with the majority of these being Chinese. Given that Aotearoa New Zealand’s population is ageing, it can be expected that there will a significant demand for aged services for Chinese older adults in our local community in the future. Exploring the language barrier encountered by retired and aged (65+) Chinese migrants living in Auckland is needed.METHOD: Two focus groups were interviewed with retired Chinese migrants (group 1) and local social service practitioners (group 2). The focus group topics included the living experience of Chinese migrants in Auckland in Aotearoa New Zealand, while local social service practitioners reported their daily work experience of serving Chinese older adults. A short, warm-up, oral questionnaire stimulated discussion in each group. Data analysis was used to identify themes and draw tentative conclusions about the needs of older migrants and suggest how local aged- services providers could better serve retired Chinese migrants.FINDINGS: Language barriers and transportation problems were commonly agreed to be obstacles that hindered retired Chinese migrants accessing social support and health services. More input was needed to improve their general English language proficiency to facilitate their daily lives and participation in social life in Aotearoa New Zealand.IMPLICATIONS: Findings from the research have the potential to be an important resource for local social service practitioners, giving them a better understanding of older Chinese people.
Voltage-gated potassium channel limbic encephalitis presenting as functional cognitive impairment
Authors: Garrels Eric , Huq Fawziya , McKay Gavin
Published: December 2020

Limbic encephalitis is often reported to present as seizures and impaired cognition with little focus on psychiatric presentations. In this case report, we present a 49-year-old man who initially presented to the Psychiatric Liaison Service with a several month history of confusion with the additional emergence of visual hallucinations and delusions. Due to the inconsistent nature of the symptoms in the context of a major financial stressor, a provisional functional cognitive impairment diagnosis was made. Investigations later revealed a positive titre of voltage-gated potassium channel (VGKC) antibodies, subtype leucine-rich glioma inactivated 1 accounting for his symptoms which dramatically resolved with steroids and immunoglobulins. This case highlighted the need for maintaining broad differential diagnoses in a patient presenting with unusual psychiatric symptoms.
Simulation-based training for increasing health service board members’ effectiveness: a cluster randomised controlled trial
Authors: Faulkner Nicholas , Wright Breanna , Lennox Alyse , Bismark Marie , Boag Jane , Boffa Sophie , Waxman Bruce , Watson-Kruse Janet , Paine Geoff , Bragge Peter
Published: December 2020

Objectives

There is a paucity of research on how to improve the functioning of health service boards, despite their importance in influencing patient care. We examined the impact of simulation-based training on health service board members’ perceptions of their skills in communicating during board meetings and of board meeting processes.

Design

Prospective, cluster randomised controlled trial.

Setting

Health service boards in Victoria, Australia.

Participants

Twelve boards were randomised, and pre- and post-intervention data were collected and analysed from 57 members of these boards.

Interventions

Boards were randomly allocated to either a treatment condition in which they received a 2-hour simulation-based training session or to a wait list control condition.

Primary and secondary outcome measures

Primary outcome variables were board members’ perceptions regarding: (1) their skill and confidence in communicating during board meetings and (2) processes at their board meetings. Measures were collected in the intervention group before and 3 months post-training and compared with a wait list control group.

Results

Skills and confidence in communicating during board meetings was higher after training (control marginal mean=5.11, intervention marginal mean=5.42, mean difference=0.31, 90% CI (−0.03 to 0.66), one-sided p=0.068, d=0.40). Board meeting processes were also improved after training (control marginal mean=4.97, intervention marginal mean=5.37, mean difference=0.40, 90% CI (0.14 to 0.65), one-sided p=0.005, d=0.54).

Conclusions

Simulation-based training appeared to improve board members’ skills and confidence, and perceptions of board meeting processes. A larger scale trial is needed to examine possible impacts on patient outcomes.

Trial registration

Open Science Framework: http://osf.io/jaxt6/; Pre-results.
Introduction to statistical simulations in health research
Authors: Boulesteix Anne-Laure , Groenwold Rolf HH , Abrahamowicz Michal , Binder Harald , Briel Matthias , Hornung Roman , Morris Tim P , Rahnenführer Jörg , Sauerbrei Willi
Published: December 2020

In health research, statistical methods are frequently used to address a wide variety of research questions. For almost every analytical challenge, different methods are available. But how do we choose between different methods and how do we judge whether the chosen method is appropriate for our specific study? Like in any science, in statistics, experiments can be run to find out which methods should be used under which circumstances. The main objective of this paper is to demonstrate that simulation studies, that is, experiments investigating synthetic data with known properties, are an invaluable tool for addressing these questions. We aim to provide a first introduction to simulation studies for data analysts or, more generally, for researchers involved at different levels in the analyses of health data, who (1) may rely on simulation studies published in statistical literature to choose their statistical methods and who, thus, need to understand the criteria of assessing the validity and relevance of simulation results and their interpretation; and/or (2) need to understand the basic principles of designing statistical simulations in order to efficiently collaborate with more experienced colleagues or start learning to conduct their own simulations. We illustrate the implementation of a simulation study and the interpretation of its results through a simple example inspired by recent literature, which is completely reproducible using the R-script available from online supplemental file 1.
Ambulatory oxygen for treatment of exertional hypoxaemia in pulmonary fibrosis (PFOX trial): a randomised controlled trial
Authors: Holland Anne E , Corte Tamera , Chambers Daniel C , Palmer Andrew J , Ekström Magnus Per , Glaspole Ian , Goh Nicole S L , Hepworth Graham , Khor Yet H , Hoffman Mariana , Vlahos Ross , Sköld Magnus , Dowman Leona , Troy Lauren K , Prasad Jyotika D , Walsh James , McDonald Christine F
Published: December 2020

Introduction

Interstitial lung diseases are characterised by scarring of lung tissue that leads to reduced transfer of oxygen into the blood, decreased exercise capacity and premature death. Ambulatory oxygen therapy may be used to treat exertional oxyhaemoglobin desaturation, but there is little evidence to support its efficacy and there is wide variation in clinical practice. This study aims to compare the clinical efficacy and cost-effectiveness of ambulatory oxygen versus ambulatory air in people with fibrotic interstitial lung disease and exertional desaturation.

Methods and analysis

A randomised, controlled trial with blinding of participants, clinicians and researchers will be conducted at trial sites in Australia and Sweden. Eligible participants will be randomised 1:1 into two groups. Intervention participants will receive ambulatory oxygen therapy using a portable oxygen concentrator (POC) during daily activities and control participants will use an identical POC modified to deliver air. Outcomes will be assessed at baseline, 3 months and 6 months. The primary outcome is change in physical activity measured by number of steps per day using a physical activity monitor (StepWatch). Secondary outcomes are functional capacity (6-minute walk distance), health-related quality of life (St George Respiratory Questionnaire, EQ-5D-5L and King’s Brief Interstitial Lung Disease Questionnaire), breathlessness (Dyspnoea-12), fatigue (Fatigue Severity Scale), anxiety and depression (Hospital Anxiety and Depression Scale), physical activity level (GENEActive), oxygen saturation in daily life, POC usage, and plasma markers of skeletal muscle metabolism, systematic inflammation and oxidative stress. A cost-effectiveness evaluation will also be undertaken.

Ethics and dissemination

Ethical approval has been granted in Australia by Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/42) with governance approval at all Australian sites, and in Sweden (Lund Dnr: 2019-02963). The results will be published in peer-reviewed scientific journals, presented at conferences and disseminated to consumers in publications for lay audiences.

Trial registration number

ClinicalTrials.gov Registry (NCT03737409).
Prevalence of multimorbidity in South Africa: a systematic review protocol
Authors: Roomaney Rifqah A , van Wyk Brian , Turawa Eunice Bolanle , Pillay-van Wyk Victoria
Published: December 2020

Introduction

Multimorbidity has increased globally over the past two decades, due to ageing populations and increased burden of non-communicable diseases (NCDs). In a country like South Africa, with a growing burden of NCDs and a high prevalence of HIV, information on multimorbidity can improve planning for healthcare delivery and utilisation, and reduce costs in the context of constrained health resources. This review aims to synthesise prevalence studies on multimorbidity, and identify dominant clusters and trends of multimorbidity in South Africa.

Methods and analysis

We will search electronic bibliographic databases (PubMed, Scopus, JSTOR, POPLINE, PsycINFO, ScienceDirect, Web of Science and CINAHL), and the reference lists of included articles. Two researchers will independently screen title and abstracts, and then full text to identify studies published before and in 2020 that report on prevalence of multimorbidity in South Africa. Risk of bias assessments will be done for each study. Information on the prevalence of multimorbidity and disease clusters will be extracted from each study. Where possible, prevalence of specific clusters of multimorbidity will be pooled using a random effects meta-analysis to account for variability between studies. The I2 statistic will be used to establish the extent of heterogeneity due to variation in prevalence estimates rather than due to chance. The systematic review will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses.

Ethics and dissemination

Only published journal articles will be included in the systematic review. This review received ethics approval as part of a larger project by the University of the Western Cape Biomedical Science Research Ethics Committee (BM20/5/8). The findings from this research will be used to estimate the prevalence of multimorbidity in South Africa and will contribute to the design of future research projects. The findings will be disseminated in a peer-reviewed journal article.

PROSPERO registration number

CRD42020196895.
Challenges and facilitators of implementation of an information communication and technology (ICT)-based human resources management tool in the government health sector in Bangladesh: protocol for an exploratory qualitative research study
Authors: Bhattacharyya Dipika Shankar , Shafique Sohana , Akhter Sadika , Rahman Aminur , Islam Md Zahidul , Rahman Nawsiba , Anwar Iqbal
Published: December 2020

Introduction

To improve human resources for health (HRH) management in Bangladesh, the directorate general of health services (DGHS) introduced a new information and communications technology (ICT) tool, named ‘human resources information system (HRIS)’, to process real-time HRH data of all facilities under the DGHS. However, synchronisation is a major concern since multiple authorities are involved in the implementation of the tool at different tiers of the health system. Introducing ICT tools in healthcare organisations has always proved challenging as evidence from low-income and middle-income countries suggests. The knowledge gap in terms of factors that support or constrain the successful implementation of the HRIS in Bangladesh will be investigated in this exploratory study to identify ways of engaging the key stakeholders in a better way for an effective use of the tool.

Methods and analysis

Desk review and qualitative data collection methods will be used to address the study objectives. Key informant interviews and in-depth interviews will be conducted to explore perspectives of policy-makers, programme managers, service providers and other stakeholders to understand the barriers to implementing HRIS in the context of Bangladesh. We plan to organise stakeholder consultation workshops to validate the qualitative study findings and to seek suggestions for ensuring a successful implementation of the HRIS. Framework analysis will be applied to analyse qualitative data, and an outline with the definitions of a priori codes guided by the policy engagement framework will be prepared. Besides, emerging themes will also be identified. A data display matrix will be prepared to summarise and interpret the findings for policy review.

Ethics and dissemination

The research review committee and the ethical review committee of icddr,b have approved the research protocol. Findings from the study will be communicated through national and international forums, conferences, policy briefs and peer-reviewed journal publications.
Characterization of tomato accessions for morphological, agronomic, fruit quality, and virus resistance traits
Authors: Grozeva Stanislava , Nankar Amol N. , Ganeva Daniela , Tringovska Ivanka , Pasev Gancho , Kostova Dimitrina
Published: December 2020

Characterization of local germplasm is an effective way to identify elite breeding material and develop improved varieties. This study was aimed to assess 52 tomato accessions comprised of local varieties (28), landraces (8), breeding lines (14), and wild relatives (2), and their characterization for 30 morphological/agronomic, four fruit quality, and tomato mosaic virus (ToMV) resistance traits. Morphological, quality, and ToMV traits were evaluated using phenotyping, biochemical assays, and molecular markers, respectively. Fruit shape and size showed appreciable variation, with fruits varying from rounded to heart shaped and small to big size. Significant variation was observed for fruit weight (1.6–564.8 g), fruits per plant (6.0–174.7), productivity (130.5–5146.5 g), soluble solids (4.1%–8.4%), vitamin C (9.5–46.4 mg·100 g−1), antioxidant activity (2.5–9.6 μmol Fe2+·g−1fresh weight), and total polyphenols (23.9–124.2 GAE·100 g−1fresh weight). All accessions were phenotypically screened for the virus resistance in the growth chamber, and CAPS molecular markers were used to identify accessions with ToMV Tm-22resistant alleles, and accessions LYC-13, LYC-15, LYC-17, LYC-26, and LYC-52 were identified as resistant. Multivariate analysis of morphological and quality traits showed that 35 principal components contributed to the total variation and the first two and 12 principal components explained 47.2% and 90% of the variation, respectively. The evaluated tomato collection appears to have breeding potential, and around 20% of the accessions in the collection (LYC-6, LYC-17, LYC-18, LYC-26 to LYC-31, and LYC 33) are promising genetic resources for variety development that are enriched with enhanced fruit quality and high yield.
Conformally flat Lorentzian hypersurfaces in Lorentzian 4-space with special shape operator
Authors: Xie Zhenxiao , Wang Changping , Wang Xiaozhen
Published: December 2020

In the conformal (Möbius) geometry of submanifolds, using algebraic invariants of the shape operator to construct conformal invariants is a frequently used method. But it does not apply to [Formula: see text]-dim Lorentzian hypersurfaces of the last type, the minimal polynomial of whose shape operator has a triple root. In this paper, using the obstruction of some distribution to be integrable, a new method to construct conformal invariants is introduced. Using this method, a complete conformal invariant system is constructed for generic conformally flat Lorentzian hypersurfaces of the last type. We find that such kind of hypersurfaces allows an infinite parameter family of non-equivalent deformations, which implies they are more abundant than the other three types. For non-generic conformally flat Lorentzian hypersurfaces of the last type, the isometric geometry is studied and a fundamental theorem is obtained in this paper.
Electrical impedance investigation of gamma-irradiated TlInS2〈5%C〉 crystals
Authors: Samedov O. A. , Alekperov O. Z. , Orudjova Kh. B. , Mehtiyev N. M. , Nadjafov A. I. , Gabulov I. A. , Huseynov E. M.
Published: December 2020

In this article, the authors carry out a pioneering study of monocrystalline TlInS[Formula: see text] at higher than room-temperatures using impedance spectroscopy. It is shown that in TlInS[Formula: see text] crystals at temperatures higher than 400 K, the nature of conductivity is predominantly ionic. Moreover, characteristics of impedance spectra behavior of TlInS[Formula: see text] monocrystal samples were studied using the measurement frequency range of 25–106 Hz. For the measured frequency range, it is shown that curves of active and reactive impedance components undergo a dispersion characterized by decreasing values of [Formula: see text] and [Formula: see text], as the frequency of the electric field and radiation dose increases.
The investigation of the acousto-photovoltaic effect in single crystals TlIn1−xGaxSe2
Authors: Gojayev E. M. , Mamedova G. N. , Osmanova S. S. , Mehdiyeva Sh. M. , Jabarov S. H.
Published: December 2020

In this work, TlIn[Formula: see text]Ga[Formula: see text]Se2 single crystals were grown by zone recrystallization methods and their X-ray phase analysis was performed. The lattice parameters were determined and it was found that crystals based on the original TlIn[Formula: see text]Ga[Formula: see text]Se2 compound crystallized in the same tetragonal symmetry, the space group [Formula: see text]. It was revealed that with partial substitution of indium atoms by gallium atoms in the TlIn[Formula: see text]Ga[Formula: see text]Se2 lattice, the parameters of unit cells change according to the additivity law. First time it was found that with the simultaneous influence of electromagnetic and sound waves, an electromotive force (e.m.f.) occurs or short circuit current. The studies were carried out in the frequency range of electromagnetic radiation of 50–143 kHz. It was revealed that when the investigated crystals were irradiated with magnetic radiation in the absence of sound waves, there was no e.m.f. on the electrodes as well as memory when exposed only to sound. Based on the existing theoretical information, the nature of the revealed single crystal of the acousto-photovoltaic effect was explained.
Nil 𝒢-cleanness and strongly nil 𝒢-cleanness of rings
Authors: Tang Gaohua , Zhou Yiqiang
Published: December 2020

A unit-picker is a map [Formula: see text] that associates to every ring [Formula: see text] a well-defined set [Formula: see text] of central units in [Formula: see text] which contains [Formula: see text] and is invariant under isomorphisms of rings and closed under taking inverses, and which satisfies certain set containment conditions for quotient rings, corner rings and matrix rings. Let [Formula: see text] be a unit-picker. A ring [Formula: see text] is called (strongly) nil [Formula: see text]-clean if for each [Formula: see text], [Formula: see text] where [Formula: see text], [Formula: see text] and [Formula: see text] is nilpotent (and [Formula: see text]). An extensive study of (strongly) nil [Formula: see text]-clean rings is conducted. When [Formula: see text] is specified, known results of the much-studied (strongly) nil-clean rings and weakly nil-clean rings are re-proved and new results of other nil-clean-like rings are obtained.
Pharmacological Activity of Eriodictyol: The Major Natural Polyphenolic Flavanone
Authors: Deng Zirong , Hassan Sabba , Rafiq Muhammad , Li Hongshui , He Yang , Cai Yi , Kang Xi , Liu Zhaoguo , Yan Tingdong
Published: December 2020

Eriodictyol is a flavonoid that belongs to a subclass of flavanones and is widespread in citrus fruits, vegetables, and medicinally important plants. Eriodictyol has been anticipated to explain the method of its activity via multiple cellular signaling cascades. Eriodictyol is an effective natural drug source to maintain higher health standards due to its excellent therapeutic roles in neuroprotection, cardioprotective activity, hepatoprotective activity, antidiabetes and obesity, and skin protection and having highly analgesic, antioxidant, and anti‐inflammatory effects, antipyretic and antinociceptive actions, antitumor activity, and much more. This review aims to highlight the modes of action of eriodictyol against various diseases via multiple cellular signaling pathways.
Scutellarein Aggravated Carbon Tetrachloride‐Induced Chronic Liver Injury in Gut Microbiota‐Dysbiosis Mice
Authors: Miao Zhimin , Lai Yong , Zhao Yingying , Chen Lingmin , Zhou Jianeng , Li Chunyan , Lan Hai
Published: December 2020

Scutellarein (SCU) is an herbal flavonoid, showing hepatoprotective potentials. The study was aimed to investigate whether the hepatoprotective effect of SCU is dependent on the integrity of gut microbiota. Mice received repeated intraperitoneal injections of CCl4, followed with or without SCU treatment (15, 30, and 60 mg/kg). Gut microbial community of mice was disrupted by administrating a cocktail of antibiotics (ampicillin, neomycin sulfate, metronidazole, and vancomycin) in drinking water. The results showed SCU plus antibiotics aggravated CCl4‐induced chronic liver injury, as demonstrated by liver function analysis, histological analysis, and TUNEL assay. SCU activated CYP2E1 expression and worsened CYP2E1‐mediated lipid peroxidation and oxidative stress as coadministered with antibiotics. Moreover, when gut microbiota was disrupted by antibiotics, SCU activated IκBα/NF‐κB pathway and promoted the release of subsequent proinflammatory cytokines including interleukin‐6 (IL‐6), interleukin‐1β (IL‐1β), and tumor necrosis factor‐α (TNF‐α). Remarkably, the 16 S rRNA sequencing demonstrated that SCU greatly decreased the relative abundance of Bifidobacterium and Lactobacillus and increased the relative abundance of Enterococcus in gut microbiota‐dysbiosis mice. Spearman correlation analysis showed that Lactobacillus was positively correlated with SOD and negatively correlated with AST. Collectively, the hepatoprotective effect of SCU is reversed under antibiotics intervention, which may partly involve the activation of CYP2E1 and IκBα/NF‐κB pathway and diminishment of Lactobacillus.
Accidental Oral Injuries by Electric Toothbrush: A Report of Three Cases
Authors: Yamada Miki , Hino Shunsuke , Nakamura Satoshi , Iijima Yosuke , Kaneko Takahiro , Horie Norio
Published: December 2020

In recent years, electric toothbrushes have become widespread. However, injuries caused by electric toothbrushes have rarely been reported. We describe three cases of oral penetrating injuries caused by electric toothbrushes. Case 1 occurred in a disabled boy while brushing due to unexpected movement. In Case 2, a mother using an electric toothbrush had fallen when bumped by her child. Case 3 involved a man using the toothbrush while taking a bath, who slipped in the bathtub. Cases 1 and 3 were using sonic toothbrushes, and Case 2 was using an oscillating-rotating toothbrush. Electric toothbrushes can cause oral penetrating injuries and infections in the same manner as manual toothbrushes. Prevention of oral trauma requires familiarity with the form and function of electric toothbrushes. Some room for improvement remains in optimizing the form of electric toothbrushes.
Study on the Dynamic Response Characteristics of Cylindrical Coal-Rock Samples under Dynamic Loads
Authors: Zhu Hongqing , Fang Shuhao , Zhang Yilong , Wu Yan
Published: December 2020

To research the dynamic response characteristics of cylindrical coal-rock samples under impact loads, the impact of rigid bars on cylindrical coal-rock samples is simulated under different speed conditions, based on LS-DYNA software, and the dynamic distribution characteristics of the stress, strain, and energy of cylindrical coal-rock samples are analyzed. The results demonstrated the following: (1) the cylindrical coal-rock sample failed at the center first, and the damage developed downward along the axial direction. (2) The critical effective stress and strain have an exponential function relationship with the velocity, and the critical time has a linear relationship with the velocity. (3) The energy change law of the cylindrical coal-rock sample is consistent with the destruction morphology. (4) The axial stress peaks in the severe damage part have a linear relationship with the speed, the axial stress attenuates rapidly after passing the stress yield point, and the axial strain does not increase continuously. (5) The peaks stress and strain on the central axis and the radial line obey the power function distribution, the axial stress produces tensile stress in the axial propagation direction, and the axial stress and strain peaks at the same position are larger than those of the radial stress and strain peaks. This research provides a reference for studying coal and rock dynamic disasters.
Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism
Authors: Bhattarai Shankar , Go Ji-Seong , Kim Hongrae , Oh Hyun-Ung
Published: December 2020

In this present work, a highly damped deployable solar panel module was developed for application in the 3 U CubeSat. The solar panel proposed herein is effective in guaranteeing the structural safety of solar cells under a launch environment owing to the superior damping characteristics achieved using multilayered stiffeners with viscoelastic acrylic tapes. A holding and release action of the solar panel was achieved by a new version of spring-loaded pogo pin-based burn wire triggering mechanism. A demonstration model of high-damping solar panel assembly was fabricated and tested to validate the effectiveness of the design. The holding and release mechanism achieved using a pogo pin was functionally tested through solar panel deployment tests under ambient room temperature and a thermal vacuum environment. The design effectiveness and structural safety of the solar panel module were validated through qualification-level launch and in-orbit environment tests.
On the Exploitation of Blockchain for Distributed File Storage
Authors: Ning Zuoting , Xiao Lijun , Liang Wei , Shi Weiqi , Li Kuan-Ching
Published: December 2020

Distributed file storage aims to support credible access to data on distributed nodes. There are some application scenarios, for example, data centers, peer-to-peer (P2P) storage systems, and storage in wireless networks. Nevertheless, among these applications, data blocks are inevitably replaced and inaccessible when there exists nodes failure. As a result, data integrity and credibility is absent. To overcome such a challenge, blockchain is explored to protect the distributed data. Through analysis and evaluation, we demonstrate that blockchain advocates data integrity and credibility for distributed file storage, as well as the application of blockchain technology for distributed file storage.
Necrotizing Soft Tissue Infection of the Breast during COVID-19 Pandemic
Authors: Kamagate Nadia , DeVito Robert
Published: December 2020

Necrotizing soft tissue infection has been historically recognized as a severe, rapidly spreading soft tissue infection associated with a very high risk of mortality. Cases of primary necrotizing fasciitis of the breast are rarely described but often fatal. We present a case of necrotizing soft tissue infection of the right breast extending to the anterior abdominal wall in a 39-year-old obese female, with a history of tobacco use. The patient presented 10 days after symptom onset due to concerns and anxiety related to COVID-19 exposure. This delay allowed for further extension and smoldering of the breast infection. The treatment of this aggressive disease process begins with early diagnosis, where a high index of suspicion is vital. Once diagnosed, the treatment regimen should be composed of emergent surgical debridement, which can include breast salvage debridement or total mastectomy, in addition to antibiotic therapy.
Identification of Predictive ERBB Mutations by Leveraging Publicly Available Cell Line Databases
Authors: Koivu Marika K.A. , Chakroborty Deepankar , Tamirat Mahlet Z. , Johnson Mark S. , Kurppa Kari J. , Elenius Klaus
Published: December 2020

Although targeted therapies can be effective for a subgroup of patients, identification of individuals who benefit from the treatments is challenging. At the same time, the predictive significance of the majority of the thousands of mutations observed in the cancer tissues remains unknown. Here, we describe the identification of novel predictive biomarkers for ERBB-targeted tyrosine kinase inhibitors (TKIs) by leveraging the genetic and drug screening data available in the public cell line databases: Cancer Cell Line Encyclopedia, Genomics of Drug Sensitivity in Cancer, and Cancer Therapeutics Response Portal. We assessed the potential of 412 ERBB mutations in 296 cell lines to predict responses to 10 different ERBB-targeted TKIs. Seventy-six ERBB mutations were identified that were associated with ERBB TKI sensitivity comparable with non–small cell lung cancer cell lines harboring the well-established predictive EGFR L858R mutation or exon 19 deletions. Fourteen (18.4%) of these mutations were classified as oncogenic by the cBioPortal database, whereas 62 (81.6%) were regarded as novel potentially predictive mutations. Of the nine functionally validated novel mutations, EGFR Y1069C and ERBB2 E936K were transforming in Ba/F3 cells and demonstrated enhanced signaling activity. Mechanistically, the EGFR Y1069C mutation disrupted the binding of the ubiquitin ligase c-CBL to EGFR, whereas the ERBB2 E936K mutation selectively enhanced the activity of ERBB heterodimers. These findings indicate that integrating data from publicly available cell line databases can be used to identify novel, predictive nonhotspot mutations, potentially expanding the patient population benefiting from existing cancer therapies.
Durable Suppression of Acquired MEK Inhibitor Resistance in Cancer by Sequestering MEK from ERK and Promoting Antitumor T-cell Immunity
Authors: Hong Aayoung , Piva Marco , Liu Sixue , Hugo Willy , Lomeli Shirley H. , Zoete Vincent , Randolph Christopher E. , Yang Zhentao , Wang Yan , Lee Jordan J. , Lo Skylar J. , Sun Lu , Vega-Crespo Agustin , Garcia Alejandro J. , Shackelford David B. , Dubinett Steven M. , Scumpia Philip O. , Byrum Stephanie D. , Tackett Alan J. , Donahue Timothy R. , Michielin Olivier , Holmen Sheri L. , Ribas Antoni , Moriceau Gatien , Lo Roger S.
Published: December 2020

MAPK targeting in cancer often fails due to MAPK reactivation. MEK inhibitor (MEKi) monotherapy provides limited clinical benefits but may serve as a foundation for combination therapies. Here, we showed that combining a type II RAF inhibitor (RAFi) with an allosteric MEKi durably prevents and overcomes acquired resistance among cancers with KRAS, NRAS, NF1, BRAFnon-V600, and BRAFV600 mutations. Tumor cell–intrinsically, type II RAFi plus MEKi sequester MEK in RAF complexes, reduce MEK/MEK dimerization, and uncouple MEK from ERK in acquired-resistant tumor subpopulations. Immunologically, this combination expands memory and activated/exhausted CD8+ T cells, and durable tumor regression elicited by this combination requires CD8+ T cells, which can be reinvigorated by anti–PD-L1 therapy. Whereas MEKi reduces dominant intratumoral T-cell clones, type II RAFi cotreatment reverses this effect and promotes T-cell clonotypic expansion. These findings rationalize the clinical development of type II RAFi plus MEKi and their further combination with PD-1/L1-targeted therapy.

Significance:

Type I RAFi + MEKi are indicated only in certain BRAFV600MUT cancers. In contrast, type II RAFi + MEKi are durably active against acquired MEKi resistance across broad cancer indications, which reveals exquisite MAPK addiction. Allosteric modulation of MAPK protein/protein interactions and temporal preservation of intratumoral CD8+ T cells are mechanisms that may be further exploited.

This article is highlighted in the In This Issue feature, p. 521
NeuroAid II (MLC901) in Haemorrhagic Stroke
Authors: Tan Chai-Hoon Nowel , Choy David , Venketasubramanian Narayanaswamy
Published: December 2020

Stroke is a leading cause of death and disability. NeuroAid (MLC601), which originates from Traditional Chinese Medicine, comprises herbal and animal components, and has been shown to improve the functional status of patients after ischaemic stroke. The use of NeuroAid II (MLC901), which comprises only the herbal components of MLC601, in haemorrhagic stroke has not been previously reported. Our patient is a 63-year-old male with a significant stroke risk factor of hypertension. He developed visual field defect, aphasia, unilateral weakness, and hemisensory loss. CT scan showed a left thalamic haemorrhage. In addition to anti-hypertensive therapy and intensive rehabilitation, he was prescribed MLC901. Over a period of 6 months, he had significant improvements in his motor, sensory, and speech function. There were no adverse events, serial brain CT scans showed resolution of the haemorrhage. MLC901 may have a role in post-stroke recovery after intracranial haemorrhage.
The Role of Calcium Signaling in Regulation of Epithelial-Mesenchymal Transition
Authors: Adiga Divya , Radhakrishnan Raghu , Chakrabarty Sanjiban , Kumar Prashant , Kabekkodu Shama Prasada
Published: December 2020

Despite substantial advances in the field of cancer therapeutics, metastasis is a significant challenge for a favorable clinical outcome. Epithelial to mesenchymal transition (EMT) is a process of acquiring increased motility, invasiveness, and therapeutic resistance by cancer cells for their sustained growth and survival. A plethora of intrinsic mechanisms and extrinsic microenvironmental factors drive the process of cancer metastasis. Calcium (Ca2+) signaling plays a critical role in dictating the adaptive metastatic cell behavior comprising of cell migration, invasion, angiogenesis, and intravasation. By modulating EMT, Ca2+ signaling can regulate the complexity and dynamics of events leading to metastasis. This review summarizes the role of Ca2+ signal remodeling in the regulation of EMT and metastasis in cancer.
Medicamentos fitoterápicos: prevalência, vantagens e desvantagens de uso na prática clínica e perfil e avaliação dos usuários
Authors: Esteves Clara Oliveira , Rodrigues Raquel Miguel , Martins Andréia Luísa Duarte , Vieira Rayana de Almeida , Barbosa Juliana Lourenço , Vilela Júlia Barbosa Ferraz
Published: December 2020

Introdução: Este trabalho realizou uma revisão de literatura acerca de aspectos do uso de fitoterápicos, medicamentos compostos a partir da extração de matérias primas vegetais ativas, que passam por um processo de industrialização. Dessa forma, identificaram-se os fitoterápicos mais utilizados, a prevalência de utilização dessa prática, vantagens e desvantagens de seu uso e o perfil e avaliação de usuários do Sistema Único de Saúde. Material e Métodos: Realizou-se um levantamento bibliográfico do período de 2014 a 2018 nas bases de dados SciELO e Lilacs. Foram utilizados os descritores “fitoterapia” e “medicamentos fitoterápicos”, sendo encontrados 353 artigos da base SciELO, sendo somente 21 selecionados para leitura e 13 utilizados para formar o artigo, enquanto na base de dados Lilacs 1490 artigos foram encontrados, 46 selecionados para leitura e 8 utilizados para elaborar o artigo. Os demais foram eliminados pelo título, por repetição ou por não se encaixarem nos critérios de inclusão. Resultados e Discussão: A partir dos 21 artigos selecionados, o conteúdo destes foi agrupado em quatro categorias: fitoterápicos mais utilizados, prevalência do uso da fitoterapia, vantagens e desvantagens da prática e perfil e avaliação dos usuários do Sistema Único de Saúde. Conclusão: Os fitoterápicos mais utilizados são o Guaco (Mikania glomerata), medicamentos à base de Passiflora, chá verde e fitoterápicos a base de Curcuma. A prevalência do uso é apontada como baixa pela maior parte dos estudos. Como desvantagem menciona-se o desconhecimento de profissionais de saúde e a menor oferta de medicamentos fitoterápicos pelo Sistema Único de Saúde, por outro lado, o estreitamento do vínculo médico-paciente é um aspecto positivo do uso dos fitoterápicos. Os usuários que fazem mais uso da fitoterapia são mulheres e indivíduos acima de 50 anos. São necessários mais estudos sobre a fitoterapia, buscando difundir uma produção de cuidado que se aproxime da população dentro de suas particularidades étnico-culturais.