bluuebunny/crossref_metadata_2025 huggingface dataset:
MZB1 enables efficient interferon α secretion in stimulated plasmacytoid dendritic cells
Authors: Kapoor Tanya , Corrado Mauro , Pearce Erika L. , Pearce Edward J. , Grosschedl Rudolf
Published: December 2020

MZB1 is an endoplasmic reticulum (ER)-resident protein that plays an important role in the humoral immune response by enhancing the interaction of the μ immunoglobulin (Ig) heavy chain with the chaperone GRP94 and by augmenting the secretion of IgM. Here, we show that MZB1 is also expressed in plasmacytoid dendritic cells (pDCs). Mzb1−/− pDCs have a defect in the secretion of interferon (IFN) α upon Toll-like receptor (TLR) 9 stimulation and a reduced ability to enhance B cell differentiation towards plasma cells. Mzb1−/− pDCs do not properly expand the ER upon TLR9 stimulation, which may be accounted for by an impaired activation of ATF6, a regulator of the unfolded protein response (UPR). Pharmacological inhibition of ATF6 cleavage in stimulated wild type pDCs mimics the diminished IFNα secretion by Mzb1−/− pDCs. Thus, MZB1 enables pDCs to secrete high amounts of IFNα by mitigating ER stress via the ATF6-mediated UPR.
Minimal system for assembly of SARS-CoV-2 virus like particles
Authors: Swann Heather , Sharma Abhimanyu , Preece Benjamin , Peterson Abby , Eldredge Crystal , Belnap David M. , Vershinin Michael , Saffarian Saveez
Published: December 2020

SARS-CoV-2 virus is the causative agent of COVID-19. Here we demonstrate that non-infectious SARS-CoV-2 virus like particles (VLPs) can be assembled by co-expressing the viral proteins S, M and E in mammalian cells. The assembled SARS-CoV-2 VLPs possess S protein spikes on particle exterior, making them ideal for vaccine development. The particles range in shape from spherical to elongated with a characteristic size of 129 ± 32 nm. We further show that SARS-CoV-2 VLPs dried in ambient conditions can retain their structural integrity upon repeated scans with Atomic Force Microscopy up to a peak force of 1 nN.
Using functional connectivity changes associated with cognitive fatigue to delineate a fatigue network
Authors: Wylie G. R. , Yao B. , Genova H. M. , Chen M. H. , DeLuca J.
Published: December 2020

Cognitive fatigue, or fatigue related to mental work, is a common experience. A growing body of work using functional neuroimaging has identified several regions that appear to be related to cognitive fatigue and that potentially comprise a “fatigue network”. These include the striatum of the basal ganglia, the dorsolateral prefrontal cortex (DLPFC), the dorsal anterior cingulate cortex (dACC), the ventro-medial prefrontal cortex (vmPFC) and the anterior insula. However, no work has been conducted to assess whether the connectivity between these regions changes as a function of cognitive fatigue. We used a task-based functional neuroimaging paradigm to induce fatigue in 39 healthy individuals, regressed the signal associated with the task out of the data, and investigated how the functional connectivity between these regions changed as cognitive fatigue increased. We observed functional connectivity between these regions and other frontal regions largely decreased as cognitive fatigue increased while connectivity between these seeds and more posterior regions increased. Furthermore the striatum, the DLPFC, the insula and the vmPFC appeared to be central ‘nodes’ or hubs of the fatigue network. These findings represent the first demonstration that the functional connectivity between these areas changes as a function of cognitive fatigue.
Yeast cell wall mannan rich fraction modulates bacterial cellular respiration potentiating antibiotic efficacy
Authors: Smith Helen , Grant Sharon , Parker Joanne , Murphy Richard
Published: December 2020

Now more than ever there is a demand to understand the mechanisms surrounding antibiotic resistance and look for alternative ways to impact phenotypic antibiotic outcome. Cellular energetics can be impacted by many bacteriostatic and bactericidal antibiotics, which affect metabolism and energy output, resulting in a reduction of cell growth or induction of cell death respectively. In this study, we provide evidence that a mannan rich fraction (MRF) from the cell wall of Saccharomyces cerevisiae modulates growth of antibiotic susceptible and resistant Escherichia coli and potentiates bactericidal antibiotic efficiency through modulation of bacterial cellular respiration. The role of MRF in modulating bactericidal impact and cellular metabolic state were assessed in E. coli by monitoring microbial growth and by measuring oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using the Seahorse XFe96 Analyser, respectively. This work further illustrates the link between bacterial susceptibility to antibiotics (phenotypic resistance) and resistance through modulation of bacterial metabolism. This is the first example of yeast MRF enabling collateral sensitivity to antibiotics in vitro and supports the search for alternative strategies to promote animal health without contributing to the growing issue of antimicrobial resistance.
Intracellular role of IL-6 in mesenchymal stromal cell immunosuppression and proliferation
Authors: Dorronsoro Akaitz , Lang Valérie , Ferrin Izaskun , Fernández-Rueda Jon , Zabaleta Lorea , Pérez-Ruiz Estibaliz , Sepúlveda Pilar , Trigueros César
Published: December 2020

Interleukin (IL)-6 is a pleiotropic cytokine involved in the regulation of hematological and immune responses. IL-6 is secreted chiefly by stromal cells, but little is known about its precise role in the homeostasis of human mesenchymal stromal cells (hMSCs) and the role it may play in hMSC-mediated immunoregulation. We studied the role of IL-6 in the biology of bone marrow derived hMSC in vitro by silencing its expression using short hairpin RNA targeting. Our results show that IL-6 is involved in immunosuppression triggered by hMSCs. Cells silenced for IL-6 showed a reduced capacity to suppress activated T-cell proliferation. Moreover, silencing of IL-6 significantly blocked the capacity of hMSCs to proliferate. Notably, increasing the intracellular level of IL-6 but not recovering the extracellular level could restore the proliferative impairment observed in IL-6-silenced hMSC. Our data indicate that IL-6 signals in hMSCs by a previously undescribed intracellular mechanism.
Betaine inhibits Toll-like receptor 4 responses and restores intestinal microbiota in acute liver failure mice
Authors: Chen Qian , Wang Yao , Jiao Fangzhou , Shi Chunxia , Pei Maohua , Wang Luwen , Gong Zuojiong
Published: December 2020

Previous research has revealed that the gut microbiome has a marked impact on acute liver failure (ALF). Here, we evaluated the impact of betaine on the gut microbiota composition in an ALF animal model. The potential protective effect of betaine by regulating Toll-like receptor 4 (TLR4) responses was explored as well. Both mouse and cell experiments included normal, model, and betaine groups. The rat small intestinal cell line IEC-18 was used for in vitro experiments. Betaine ameliorated the small intestine tissue and IEC-18 cell damage in the model group by reducing the high expression of TLR4 and MyD88. Furthermore, the intestinal permeability in the model group was improved by enhancing the expression of the (ZO)-1 and occludin tight junction proteins. There were 509 operational taxonomic units (OTUs) that were identified in mouse fecal samples, including 156 core microbiome taxa. Betaine significantly improved the microbial communities, depleted the gut microbiota constituents Coriobacteriaceae, Lachnospiraceae, Enterorhabdus and Coriobacteriales and markedly enriched the taxa Bacteroidaceae, Bacteroides, Parabacteroides and Prevotella in the model group. Betaine effectively improved intestinal injury in ALF by inhibiting the TLR4/MyD88 signaling pathway, improving the intestinal mucosal barrier and maintaining the gut microbiota composition.
Gas hydrate versus seabed morphology offshore Lebu (Chilean margin)
Authors: Vargas-Cordero Iván , Tinivella Umberta , Villar-Muñoz Lucía , Bento Joaquim P. , Cárcamo Carolina , López-Acevedo Diego , Fernandoy Francisco , Rivero Alessandra , Juan Marion San
Published: December 2020

Gas-hydrate occurrences along the Chilean margin have been widely documented, but the processes associated with fluid escapes caused by the dissociation of gas hydrates are still unknown. We report a seabed morphology growth related to fluid migration offshore Lebu associated with mud cones by analysing oxygen and deuterium stable water isotopes in pore water, bathymetric, biological and sedimentological data. A relief was observed at − 127 m water depth with five peaks. Enrichment values of δ18O (0.0–1.8‰) and δD (0.0–5.6‰) evidenced past hydrate melting. The orientation of the relief could be associated with faults and fractures, which constitute pathways for fluid migration. The benthic foraminifera observed can be associated with cold seep areas. We model that the mud cones correspond to mud growing processes related to past gas-hydrate dissociation. The integration of (i) the seismic data analysis performed in the surrounding area, (ii) the orientation of our studied relief, (iii) the infaunal foraminifera observed, (iv) the grain size and (v) the total organic matter and isotope values revealed that this area was formerly characterised by the presence of gas hydrates. Hence, this part of the Chilean margin represents a suitable area for investigating fluid-migration processes.
Samul-tang ameliorates oocyte damage due to cyclophosphamide-induced chronic ovarian dysfunction in mice
Authors: Kim Jihyun , You Sooseong
Published: December 2020

Samul-tang (SM), a traditional herbal medicine, has been used to treat menstrual irregularities and infertility in women. However, the cellular and molecular mechanisms underlying the effects of SM remain elusive. We investigated the potential protective effect of SM against chronic ovarian dysfunction and used bioinformatics analysis to identify its underlying mechanism in a mouse model of cyclophosphamide (CP)-induced diminished ovarian reserve. Female C57BL/6 mice were intraperitoneally injected with CP three times a week, followed by oral administration of distilled water (CP group) or SM (CP + SM group) for 4 weeks. Four weeks later, the effect of SM was assessed by ovarian tissue histological analysis, steroid hormone measurement, oocyte quality, and mRNA and microRNA microarray analysis in the ovaries. Although SM administration did not prevent CP-induced follicle loss in mice, the quality of oocytes was better in CP + SM mice than in CP mice. Gene expression analysis revealed that the expression of fertilisation- and ovarian follicle development-related genes was altered by CP treatment but normalized after SM administration. Further bioinformatics analysis showed possible interactions between differentially expressed mRNAs and microRNAs. Therefore, we demonstrated the protective effects of SM on ovarian function and oocyte maturation against CP-induced damage via multiple epigenetic mechanisms.
A negative binomial regression model for risk estimation of 0–2 axillary lymph node metastases in breast cancer patients
Authors: Zeng De , Lin Hao-Yu , Zhang Yu-Ling , Wu Jun-Dong , Lin Kun , Xu Ya , Chen Chun-Fa
Published: December 2020

Extensive clinical trials indicate that patients with negative sentinel lymph node biopsy do not need axillary lymph node dissection (ALND). However, the ACOSOG Z0011 trial indicates that patients with clinically negative axillary lymph nodes (ALNs) and 1–2 positive sentinel lymph nodes having breast conserving surgery with whole breast radiotherapy do not benefit from ALND. The aim of this study is therefore to identify those patients with 0–2 positive nodes who might avoid ALND. A total of 486 patients were eligible for the study with 212 patients in the modeling group and 274 patients in the validation group, respectively. Clinical lymph node status, histologic grade, estrogen receptor status, and human epidermal growth factor receptor 2 status were found to be significantly associated with ALN metastasis. A negative binomial regression (NBR) model was developed to predict the probability of having 0–2 ALN metastases with the area under the curve of 0.881 (95% confidence interval 0.829–0.921, P < 0.001) in the modeling group and 0.758 (95% confidence interval 0.702–0.807, P < 0.001) in the validation group. Decision curve analysis demonstrated that the model was clinically useful. The NBR model demonstrated adequate discriminative ability and clinical utility for predicting 0–2 ALN metastases.
Hemistepsin A suppresses colorectal cancer growth through inhibiting pyruvate dehydrogenase kinase activity
Authors: Jin Ling , Kim Eun-Yeong , Chung Tae-Wook , Han Chang Woo , Park So Young , Han Jung Ho , Bae Sung-Jin , Lee Jong Rok , Kim Young Woo , Jang Se Bok , Ha Ki-Tae
Published: December 2020

Most cancer cells primarily produce their energy through a high rate of glycolysis followed by lactic acid fermentation even in the presence of abundant oxygen. Pyruvate dehydrogenase kinase (PDK) 1, an enzyme responsible for aerobic glycolysis via phosphorylating and inactivating pyruvate dehydrogenase (PDH) complex, is commonly overexpressed in tumors and recognized as a therapeutic target in colorectal cancer. Hemistepsin A (HsA) is a sesquiterpene lactone isolated from Hemistepta lyrata Bunge (Compositae). Here, we report that HsA is a PDK1 inhibitor can reduce the growth of colorectal cancer and consequent activation of mitochondrial ROS-dependent apoptotic pathway both in vivo and in vitro. Computational simulation and biochemical assays showed that HsA directly binds to the lipoamide-binding site of PDK1, and subsequently inhibits the interaction of PDK1 with the E2 subunit of PDH complex. As a result of PDK1 inhibition, lactate production was decreased, but oxygen consumption was increased. Mitochondrial ROS levels and mitochondrial damage were also increased. Consistent with these observations, the apoptosis of colorectal cancer cells was promoted by HsA with enhanced activation of caspase-3 and -9. These results suggested that HsA might be a potential candidate for developing a novel anti-cancer drug through suppressing cancer metabolism.
Logistic regression analysis of environmental and other variables and incidences of tuberculosis in respiratory patients
Authors: Pathak Ashutosh K. , Sharma Mukesh , Katiyar Subodh K. , Katiyar Sandeep , Nagar Pavan K.
Published: December 2020

The objective of this study was to examine the association of 14 variables with TB in respiratory patients. The variables included: urban/rural, persons in 1200 sqft area, TB in family, crowding, smoking (family member), gender, age, education, smoking, workplace, kitchen location, cooking fuel, ventilation, and kerosene uses. Eight hundred respiratory patients were tested for sputum positive pulmonary TB; 500 had TB and 300 did not. An analysis of the unadjusted odds ratio (UOR) and adjusted OR (AOR) was undertaken using logistic regression to link the probability of TB incidences with the variables. There was an inconsistency in the significance of variables using UOR and AOR. A subset model of 4 variables (kerosene uses, ventilation, workplace, and gender) based on significant AOR was adjudged acceptable for estimating the probability of TB incidences. Uses of kerosene (AOR 2.62 (1.95, 3.54)) consistently related to incidences of TB. It was estimated that 50% reduction in kerosene uses could reduce the probability of TB by 13.29% in respiratory patients. The major recommendation was to replace kerosene uses from households with a supply of clean fuel like liquid petroleum or natural gas and rural electrification.
Functional and computational identification of a rescue mutation near the active site of an mRNA methyltransferase
Authors: Colin Pierre-Yves , Dalby Paul A.
Published: December 2020

RNA-based drugs are an emerging class of therapeutics combining the immense potential of DNA gene-therapy with the absence of genome integration-associated risks. While the synthesis of such molecules is feasible, large scale in vitro production of humanised mRNA remains a biochemical and economical challenge. Human mRNAs possess two post-transcriptional modifications at their 5′ end: an inverted methylated guanosine and a unique 2′O-methylation on the ribose of the penultimate nucleotide. One strategy to precisely methylate the 2′ oxygen is to use viral mRNA methyltransferases that have evolved to escape the host’s cell immunity response following virus infection. However, these enzymes are ill-adapted to industrial processes and suffer from low turnovers. We have investigated the effects of homologous and orthologous active-site mutations on both stability and transferase activity, and identified new functional motifs in the interaction network surrounding the catalytic lysine. Our findings suggest that despite their low catalytic efficiency, the active-sites of viral mRNA methyltransferases have low mutational plasticity, while mutations in a defined third shell around the active site have strong effects on folding, stability and activity in the variant enzymes, mostly via network-mediated effects.
Airfoil leading edge blowing to control bow shock waves
Authors: Lozano Francisco , Paniagua Guillermo
Published: December 2020

This manuscript presents a detailed characterization of active control of bow shock waves via leading edge injection, including subsonic coolant ejection and the appearance of Coanda effects. The flow phenomena occurring at steady and pulsating flow injection regimes were analyzed using steady and unsteady two-dimensional Reynolds-Averaged Navier Stokes, leading to a precise evaluation of the thermal load and drag reductions. Steady supersonic injection yields the largest abatement in thermal load and aerodynamic drag, while subsonic or fluctuating ones can also provide significant improvements at reduced cooling mass flow rates. Furthermore, a Coanda effect, causing a non-symmetric flow topology, was observed and analyzed for reduced injection port size. This Coanda effect is due to the sudden expansion happening from the injection port to the main flow and it causes the flow topology at the leading edge to become non-symmetric despite the complete symmetry of the problem. This is the first time in the literature such a phenomenon is documented for a supersonic airfoil leading edge injection. Furthermore, it enables the design of novel flow control strategies for the leading edge shock topology and flow structures in supersonic flows.
Ocean acidification may be increasing the intensity of lightning over the oceans
Authors: Asfur Mustafa , Silverman Jacob , Price Colin
Published: December 2020

The anthropogenic increase in atmospheric CO2 is not only considered to drive global warming, but also ocean acidification. Previous studies have shown that acidification will affect many aspects of biogenic carbon uptake and release in the surface water of the oceans. In this report we present a potential novel impact of acidification on the flash intensity of lightning discharged into the oceans. Our experimental results show that a decrease in ocean pH corresponding to the predicted increase in atmospheric CO2 according to the IPCC RCP 8.5 worst case emission scenario, may increase the intensity of lightning discharged into seawater by approximately 30 ± 7% by the end of the twenty-first century relative to 2000.
Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores
Authors: Cimoli Emiliano , Lucieer Vanessa , Meiners Klaus M. , Chennu Arjun , Castrisios Katerina , Ryan Ken G. , Lund-Hansen Lars Chresten , Martin Andrew , Kennedy Fraser , Lucieer Arko
Published: December 2020

Ice-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial biomass that is significant, but difficult to quantify. We address this methodological gap by employing a field-deployable hyperspectral scanning and photogrammetric approach to study sea-ice cores. The optical set-up facilitated unsupervised mapping of the vertical and horizontal distribution of phototrophic biomass in sea-ice cores at mm-scale resolution (using chlorophyll a [Chl a] as proxy), and enabled the development of novel spectral indices to be tested against extracted Chl a (R2 ≤ 0.84). The modelled bio-optical relationships were applied to hyperspectral imagery captured both in situ (using an under-ice sliding platform) and ex situ (on the extracted cores) to quantitatively map Chl a in mg m−2 at high-resolution (≤ 2.4 mm). The optical quantification of Chl a on a per-pixel basis represents a step-change in characterising microspatial variation in the distribution of ice-associated algae. This study highlights the need to increase the resolution at which we monitor under-ice biophysical systems, and the emerging capability of hyperspectral imaging technologies to deliver on this research goal.
Protein–Protein Interaction Networks in Human Disease
Authors: Dunn Brandon S. , Awasthi Sharad , Yi S. Stephen , Sahni Nidhi
Published: December 2020

Protein–protein interactions (PPIs) are a foundational life process. Much work over the past few decades has uncovered countless roles that protein–protein interactions play in both health and disease. Most of this work examined the interactions between only two proteins at a time. Recently, however, there has been a surge of research examining entire networks of PPIs in disease conditions. This chapter covers the basic principles of PPI network analysis, methodologies commonly employed to generate PPI networks, and the role that PPI network analysis plays in diverse diseases, including cancer, diabetes, and neurodegenerative diseases, among others.
Discovery and Development of Mcl-1 Inhibitors as Anti-cancer Therapeutics: Hit to Clinical Candidate Optimization
Authors: Kump Karson J. , Nikolovska-Coleska Zaneta
Published: December 2020

Recent advances in drug screening and development strategies have accelerated the discovery of novel anti-cancer modalities. Targeting protein–protein interactions in particular has become a hot area in drug discovery and has enabled the ability to drug prominent therapeutic targets, such as the Bcl-2 family of apoptosis regulators. The Bcl-2 protein family member, Mcl-1, has emerged as a critical target across a vast array of cancers, playing a key role in preventing apoptosis. Many types of cancer rely on Mcl-1 for survival, which promotes de novo and acquired resistance to standard-of-care therapies. Herein, we survey the history and advancement of small molecule Mcl-1 inhibitors, from novel screening approaches and hit optimization to clinical candidates. The drug discovery efforts spanning academia and industry have afforded five different Mcl-1 inhibitors that are currently being evaluated in phase I clinical trials to treat a variety of hematological malignancies. The most forefront and seminal Mcl-1 inhibitor development programs are summarized from their medicinal chemistry efforts and structure activity relationship studies to their biological efficacy demonstrating utility as anti-cancer agents. This chapter serves as a current state of Mcl-1 inhibitor development and contains a wealth of medicinal chemistry knowledge towards drugging protein–protein interactions.
Small-molecule Modulators of Protein–Protein Interactions: Focus on 14-3-3 PPIs
Authors: Iralde-Lorente L. , Botta M. , Ottmann C.
Published: December 2020

Small-molecule modulation of protein–protein interactions (PPIs) is one of the most promising approaches for drug discovery and chemical biology. In this chapter we give a brief overview of some important concepts and examples with a focus on modulators of binding of the adaptor protein 14-3-3 to its multitude of targets, many of which are of high medical relevance.
Development of putrescine anchored nano-crystalsomes bearing doxorubicin and oleanolic acid: deciphering their role in inhibiting metastatic breast cancer
Authors: Shukla Ravi Prakash , Urandur Sandeep , Banala Venkatesh Teja , Marwaha Disha , Gautam Shalini , Rai Nikhil , Singh Neha , Tiwari Pratiksha , Shukla Prashant , Mishra Prabhat Ranjan
Published: December 2020

Angiogenesis driven tumor initiation and progression calls for a targeted therapy.
Is the reaction sequence in phosphine-catalyzed [8+2] cycloaddition controlled by electrophilicity?
Authors: Lin Wen-Xuan , Pei Zhuolin , Gong Cunxi , Mo Huilin , Yang Kai , Qu Ling-Bo , Wei Donghui , Song Jin-Shuai , Li Shi-Jun , Lan Yu
Published: December 2020

The sequence and priority influenced by electrophilicity.
A new 3D luminescent Ba-organic framework with high open metal sites: CO2 fixation, luminescence sensing, and dye sorption
Authors: Wang Meng , Liu Jiao , Jin Jing , Wu Dan , Yang Guoping , Zhang Wen-Yan , Wang Yao-Yu
Published: December 2020

A new synthesized 3D luminescent Ba-organic framework (1) may be used as a recyclable heterogeneous catalyst for fixation of CO2 and has excellent response and sensitivity for pollutant ions. Moreover, 1 exhibits the particular selective sorption towards Congo red (CR) dye.
A theoretical design of photodetectors based on two-dimensional Sb/AlAs type-II heterostructures
Authors: Jia Yifan , Wei Xing , Zhang Zhihui , Liu Jian , Tian Ye , Zhang Yan , Guo Tingting , Fan Jibin , Ni Lei , Luan Lijun , Duan Li
Published: December 2020

Sb/AlAs heterostructures with direct-gap and type-II band alignment can effectively facilitate the spatial separation of photogenerated carriers.
Free energy profile analysis to identify factors activating the aggregation-induced emission of a cyanostilbene derivative
Authors: Yamamoto Norifumi
Published: December 2020

The contributing factors that cause the aggregation-induced emission (AIE) are determined by identifying characteristic differences in the free energy profiles of the AIE processes of the AIE-active E-form of CN-MBE and the inactive Z-form.
Phenomenology of the heating, melting and diffusion processes in Au nanoparticles
Authors: Bertoldi Dalía S. , Millán Emmanuel N. , Fernández Guillermet A.
Published: December 2020

The paper reports the results of a MD study of the heating and melting process of Au nanoparticles. A physico-chemical isomerization-like model of the melting step accounts for structural, thermodynamic and diffusion results, trends and interrelations.
Acidity constant and DFT-based modelling of pH-responsive alendronate loading and releasing on propylamine-modified silica surface
Authors: Ahmed Khalid , Inamdar Shaukatali Najikhan , Rohman Nashiour , Skelton Adam A.
Published: December 2020

A computational methodology that couples the acidity (Ka) and density functional theory (DFT) calculations has been developed to explain the pH-dependent drug loading on and releasing from mesoporous silica nanoparticles.
Dinuclear gold catalysis
Authors: Wang Wenliang , Ji Cheng-Long , Liu Kai , Zhao Chuan-Gang , Li Weipeng , Xie Jin
Published: December 2020

This review summarizes the recent achievements of dinuclear gold-catalyzed redox coupling, asymmetric catalysis and photocatalysis. The dinuclear gold catalysts show a better catalytic performance than the mononuclear gold catalysts in certain cases.
Strong-field induced fragmentation and isomerization of toluene probed by ultrafast femtosecond electron diffraction and mass spectrometry
Authors: Xiong Yanwei , Borne Kurtis , Carrascosa Andrés Moreno , Saha Sajib Kumar , Wilkin Kyle J. , Yang Mengqi , Bhattacharyya Surjendu , Chen Keyu , Du Wenpeng , Ma Lingyu , Marshall Nathan , Nunes J. Pedro F. , Pathak Shashank , Phelps Zane , Xu Xuan , Yong Haiwang , Lopata Kenneth , Weber Peter M. , Rudenko Artem , Rolles Daniel , Centurion Martin
Published: December 2020

We investigate the fragmentation and isomerization of toluene molecules induced by strong-field ionization with a femtosecond near-infrared laser pulse.
Extraction and purification of saponins from Sapindus mukorossi
Authors: Chen Chunyan , Li Ruili , Li Dongsheng , Shen Fangyuan , Xiao Guoqing , Zhou Jian
Published: December 2020

Fermentation was used to further purify saponins extracted from the pericarp of Sapindus; both the purity and foam half-life was greatly increased.
The visible light-driven highly efficient photocatalytic properties of Cu2ZnSnS4 nanoparticles synthesized by a hydrothermal method
Authors: Hou Zhangchen , Li Yufang , Liu Jinsong , Shen Honglie , Huo Xiaomin
Published: December 2020

A flower-like CZTS with high photocatalytic activity was prepared, and its photocatalytic degradation mechanism is proposed.
Optimal quantum dot size for photovoltaics with fusion
Authors: Sherrie Benedicta , Funston Alison M. , Frazer Laszlo
Published: December 2020

Solar cells do not use all the light from the sun. Light fusion can help a solar cell use more of the solar spectrum. We identify the optimal quantum dot size for sensitizing triplet annihilation. We predict increased photocurrent.
Extracellular electron transfer across bio-nano interfaces for CO2 electroreduction
Authors: Li Zhaodong , Xiong Wei , Tremolet de Villers Bertrand J. , Wu Chao , Hao Ji , Blackburn Jeffrey L. , Svedruzic Drazenka
Published: December 2020

Studies of extracellular electron transfer mechanisms across the bacterium/material interface in a model biocathode.
A supramolecular polymer with ultra-stretchable, notch-insensitive, rapid self-healing and adhesive properties
Authors: Zhang Lun , Wang Dong , Xu Liqiang , Zhang Aimin
Published: December 2020

Supramolecular elastomers, possessing excellent mechanical, reusable adhesivity, and rapid self-healing properties, are essential for use in various applications.
Retraction: A self-assembled supramolecular natural product gel from liquidambaric acid in traditional Chinese medicine with inherent anti-inflammatory activity for drug delivery
Authors: Zhi Kangkang , Wang Jiacheng
Published: December 2020

Retraction for ‘A self-assembled supramolecular natural product gel from liquidambaric acid in traditional Chinese medicine with inherent anti-inflammatory activity for drug delivery’ by Kangkang Zhi et al., J. Mater. Chem. B, 2020, 8, 715–726, DOI: 10.1039/C9TB02416F.
High performance gas sensors with dual response based on organic ambipolar transistors
Authors: Zhou Xu , Wang Zi , Song Ruxin , Zhang Yadan , Zhu Lunan , Xue Di , Huang Lizhen , Chi Lifeng
Published: December 2020

A high performance organic ambipolar transistor-based gas sensor was constructed. It demonstrates dual response features and good selectivity.
Multistep optimization of a cell-penetrating peptide towards its antimicrobial activity
Authors: Drexelius Marco , Reinhardt Andre , Grabeck Joshua , Cronenberg Tom , Nitsche Frank , Huesgen Pitter F. , Maier Berenike , Neundorf Ines
Published: December 2020

Multidrug resistant (MDR) bacteria have adapted to most clinical antibiotics and are a growing threat to human health. One promising type of candidates for the everlasting demand of new antibiotic compounds constitute antimicrobial peptides (AMPs). These peptides act against different types of microbes by permeabilizing pathogen cell membranes, whereas being harmless to mammalian cells. Contrarily, another class of membrane-active peptides, namely cell-penetrating peptides (CPPs), is known to translocate in eukaryotic cells without substantially affecting the cell membrane. Since CPPs and AMPs share several physicochemical characteristics, we hypothesized if we can rationally direct the activity of a CPP towards antimicrobial activity. Herein, we describe the screening of a synthetic library, based on the CPP sC18, including structure-based design to identify the active residues within a CPP sequence and to discover novel AMPs with high activity. Peptides with increased hydrophobicity were tested against various bacterial strains, and hits were further optimized leading to four generations of peptides, with the last also comprising fluorinated amino acid building blocks. Interestingly, beside strong antibacterial activities, we also detected activity in cancer cells, while non-cancerous cells remained unharmed. The results highlight our new candidates, particularly those from generation 4, as a valuable and promising source for the development of future therapeutics with antibacterial activity and beyond.
Follow-Up Care for Pediatric Hearing Aid Users at an Audiology Clinic in Malawi
Authors: Brough Helen , Kachaje Tiwaope
Published: December 2020

Purpose

Hearing loss can have a negative impact on a child's development. Hearing aids, if fitted appropriately, maintained well, and used regularly, can offer benefit to children with hearing loss. Regular reviews of hearing aid users can help to monitor a child's progress and provide timely intervention when problems arise or needs change. This study investigates the follow-up care received by children fitted with hearing aids at a clinic in Malawi.

Method

A clinical audit was done of the frequency of face-to-face follow-up appointments, following which all pediatric hearing aid users who had not recently received follow-up care were called to invite them for a review, and then a re-audit was conducted.

Results

Of the 47 children in the audit, 46 had not had a recent face-to-face follow-up appointment. Strenuous efforts were made to call those 46 children to the clinic for review: 20 caregivers agreed to bring their child for review, 10 of whom attended. It was not possible to contact 24 caregivers.

Conclusions

Reasons for low attendance for review at this service are not known, but may be related to the financial circumstances of the patients' families as well as difficulty in maintaining contact with families. It has not yet been possible to establish a system for routine follow-up care for pediatric hearing aid users at this well-established clinic in a low-income country.
Low‐complexity channel estimation for time division duplex massive multi‐user multi‐input multi‐output systems
Authors: Hawej Muamer , Shayan Yousef R.
Published: December 2020

This paper addresses the problem of minimum mean square error channel estimator for time division duplex massive multi‐user multi‐input multi‐output systems. It is noteworthy that, the minimum mean square error has been previously proposed for multi‐cell massive multi‐user multi‐input multi‐output channel estimation. However, the minimum mean square error estimator suffers from high computational complexity due to the large dimension of the covariance matrix inversion. In this study, low‐complexity channel estimator for time division duplex massive multi‐user multi‐input multi‐output networks is designed by using the low‐rank matrix approximation techniques. The proposed estimator is referred to as an approximate minimum mean square error estimator. Furthermore, the computational complexity of the proposed approximate minimum mean square error estimator is analysed and compared to the minimum mean square error and least square estimators. The normalised mean square error and the uplink achievable sum‐rate performance criteria are used to evaluate the performance of the proposed estimator. Finally, the simulation results show the effectiveness of the proposed estimator under two different scenarios: noise‐limited and pilot contamination. These simulation results are compared to the conventional minimum mean square error and least square estimators.
An extended winding function model for induction machine modelling considering saturation effect
Authors: Gholami Mehrdad , Shahryari Om‐Kolsoom , Tarimoradi Hadi
Published: December 2020

Winding function (WF) method is one of the electric machines modelling methods, which is used to simulate electric machines under different conditions. It has less simulation time and memory than other methods and, at the same time, has comparable accuracy over other methods. One of the significant challenges of WF‐based models is how to model saturation. The accuracy of the fault detection method in electric machines depends on the accuracy of the model and the method used for the simulation. A new extended model of the WF is presented for saturation modelling, which considers all parts of the core including teeth, slots, and yokes. In this method, the effect of the iron parts is emulated as a partial value that is added to the length of the actual air gap. The simulation results for normal and faulty conditions are shown in two cases, with and without considering saturation effect. Then the importance of saturation modelling has been demonstrated. Simulation is done in MATLAB software. Moreover, the experimental results are shown to verify the proposed model.
Low‐carbon energy policy analysis based on power energy system modeling
Authors: Han Xiao , Qiu Jing , Sun Lingling , Shen Wei , Ma Yuan , Yuan Dong
Published: December 2020

The effect of carbon policies and mechanisms on the behavior of market participants and market equilibrium has been increasingly recognized, of which tax incidence is one of these important issues. Tax incidence is the market output of both producers and consumers that respond to taxes with market equilibrium, whether the tax is levied on sellers or buyers. This paper aims to study the carbon tax incidence on the transmission level of a power system based on different carbon tax collection methods in electricity market environment. A statistical demand elasticity model, power flow and carbon emission flow models are applied to simulate the electricity market equilibrium to analyze the effects of the tax levied on demand‐side or supply‐side. Furthermore, the Australian 59‐bus system is employed in the case study with four stages and four main cases. The results demonstrate that consumers share more burden of the carbon tax in all carbon tax collection methods. Moreover, the proportion of the tax burden and emission reduction effect are different in each method and degree of renewable energy capacity. The results of this paper contribute to the establishment of emission‐related energy policies toward a low‐carbon economy.
An enhanced full‐feedforward strategy to mitigate output current harmonics in grid‐tied inverters
Authors: Gharani Khajeh Kiarash , Solatialkaran Davood , Zare Firuz , Mithulananthan Nadarajah
Published: December 2020

The grid‐tied inverters are the most vital components in renewable energy‐based power systems. Hence, maintaining the power quality of a grid‐tied inverter output within the standard range is an ongoing challenge in the power system. The appeared individual harmonics at inverter output current caused by grid voltage harmonics depend on the inverter output equivalent admittance. This consists of a combination of admittance seen from the point of common coupling and the phase‐locked loop path. Therefore, the precise calculation of the aforementioned admittance is an inevitable requirement to design a harmonic mitigation strategy. By adding a virtual admittance to the system through modifications in the inverter control loop, the output equivalent admittance can be removed. For this purpose, in this paper, a novel full‐feedforward harmonic suppression scheme is proposed which can effectively eliminate individual harmonics injected from the grid. Consequently, the individual output current harmonics of the inverter will be effectively suppressed. Simulation and experimental results have been carried out for a typical single‐phase grid‐tied inverter to verify the efficiency of the proposed scheme against emitted harmonics from the grid.
Interval power flow calculation algorithm for multi‐terminal dc distribution networks considering distributed generation output uncertainties
Authors: Liu Qi , Wang Shouxiang , Zhao Qianyu , Wang Kai
Published: December 2020

An interval power flow calculation (PFC) algorithm for multi‐terminal DC distribution networks is proposed to handle the uncertainties of distributed generation output powers and loads. Firstly, an equivalent resistance is introduced to represent the effect of droop control in DC distribution networks. The power losses of the equivalent resistance are offset by adding the injection powers to droop nodes, which guarantees the precision of the equivalent resistance model. The Newton–Raphson method is used for deterministic PFC based on the equivalent resistance, and it is applicable to DC distribution networks with different kinds of network topologies and voltage source converter control modes. Secondly, based on the deterministic PFC algorithm and affine arithmetic, an interval PFC algorithm is presented to handle the uncertainties of distributed generation output powers and loads. The affine arithmetic based interval PFC algorithm not only can determine power flow intervals quickly and accurately, but also can analyse the influences of distributed generation outputs to nodal voltages. Finally, a series of test systems are used to validate the proposed algorithms. Simulation results illustrate the accuracy and efficiency of the deterministic PFC algorithm and the interval PFC algorithm for multi‐terminal DC distribution networks.
Failure investigation and asset management of combined measuring instrument transformers
Authors: Tee ShengJi , Liu Qiang , Wang Zhongdong , Hafid Fikri , Tournet Pierre
Published: December 2020

Asset management of instrument transformers (ITs) has gained momentum in recent years due to their large population in the network and the potential adverse impacts of their increasing number of failures. This study investigates the failure cause of a family of combined measuring ITs via temperature profile simulations and consideration of moisture migration behaviour in an oil‐impregnated paper insulation system. The temperature difference experienced by an IT, particularly throughout summer, together with a relative saturation hysteresis phenomenon could have caused a lower dielectric strength that led to failures. The study also offers insights into factors influencing the probability of failures through analysis on the lifetime data from both graphical survival function plots and statistical Cox model. In‐service age, operating voltage level and environment appear to have an influence on failure rate.
Deep multi‐level up‐projection network for single image super‐resolution
Authors: Shen Yan , Zhang Liao , Chen Yun , Xie Yi , Wang Zhongli , Shao Xiaotao
Published: December 2020

Most convolutional neural network‐based single image super‐resolution (SR) methods do not take full account of the hierarchical features of the original low‐resolution (LR) images, including the intra‐channel spatial feature information and the inter‐channel feature information, which decreases the representational capacity of the network. A deep multi‐level upprojection network (DMUN) is proposed to solve this problem. Local feature up‐projection unit is adopted in DMUN to obtain high‐resolution (HR) feature of different levels and then to reconstruct the SR image. Residual up‐projection group in DMUN mines the hierarchical LR feature information and its corresponding HR residual information recursively. A residual recorrection mechanism is further introduced, which adopts HR residual information to re‐correct HR features and enrich the details of the output image. Finally, the original residual block with spatial‐and‐channel attention mechanism is improved, which adaptively recalibrates features by considering the intra‐channel spatial relationships and the inter‐channel pixel‐wise interdependencies simultaneously. Experiments on benchmark datasets show that DMUN achieves favourable performance against state‐of‐the‐art methods.
Mode diagnostics of pipeline systems of the energetics
Authors: Sukharev Mikhail
Published: December 2020

The paper proposes a method for diagnosing gradual failures in pipeline power systems, based on tracking the dynamics of flow regime parameters. The method also makes it possible to promptly adjust the coefficients of a mathematical model of the system objects. Conclusions are made based on the analysis of the entire set of measurements, which are considered random variables due to measurement errors. Conclusions are made based on the analysis of the entire set of measurements, which are considered random variables due to instrumental errors. Examples of a gas pumping unit and a complex looped gas pipeline system are given. Calculations are performed using standard software.
Comparative analysis of the trend in the stability and efficiency of the performance of energy sector of Azerbaijan
Authors: Nasibov Valeh , Alizade Rana
Published: December 2020

Methodological and practical aspects of determining the trends in the stability and efficiency of the energy sector of Azerbaijan for 2013-2018, based on the methodology presented by the World Energy Council (WEC) and the World Economic Forum (WEF) are analyzed in the paper. The basis of the methodology for assessing the stability and efficiency of the energy sector is the developed method of use of energy tetrahedron, where the vertices are economic growth and development, energy security and energy accessibility and environmental sustainability, where a set of indicators with their weight coefficients is used to evaluate each of the subsystems. The number of indicators and, naturally, the weight coefficients are adjusted with time for the most complete taking into account of all the features of the energy sector. Trends in the values of stability and efficiency of the Azerbaijan’s energy sector for the period under consideration are determined taking into account all available indicators; potentials for improvement for each of the subsystems are identified.
Research of the influence of power engineering equipment accident rate on the indicators of adequacy and the value of operating reserve of electrical power system
Authors: Krupenev Dmitry , Boyarkin Denis , Yakubovskii Dmitrii , Severina Yana
Published: December 2020

Reliable source information is necessary for a correct adequacy assessment of electric power systems. Among a wide set of initial information, coefficients of accident rates of power engineering equipment are important. The analysis of methods for determining the coefficients of accident rates of power engineering equipment, which are used in the assessment of the adequacy of electric power systems, is presented in the article, also the features of accounting for coefficients of accident rates are elicited. The experimental part of the article is showed the influence of generating aggregates accident rate on the level of operating reserve on the example ofthe Unified Energy System of Russia.
On reliability characteristics and service time limits of 500 kV overhead lines
Authors: Galiaskarov Irek
Published: December 2020

The results are given of statistical analysis of the values of the failure rate (failure frequency) and its structure for overhead lines (OHL) 500 kV of the European part of the country over a long time period. The age structure of the 500 kV OHL is presented, according to which about 40% of the OHL have developed a normative service time of more than 50 years. It is shown, that an increase in the duration of the OHL operation from about 30 to 60 years leads to a doubling of their accident rate. The maximum possible service time period of 500 kV ОНL was estimated. For this purpose, instrumental surveys of the strength property of reinforced-concrete foundations and the degree of corrosive deterioration rate of 500 kV OHL steel transmission tower in three regions of the country were carried out: Vologda, Moscow and Volgograd regions. It is shown that the most critical element of 500 kV OHL affecting the service time limit is their transmission towers. Moreover, the degree of wear condition of the metal of the transmission towers depends on natural-climatic and man-made factors and decreases from the southern to the northern regions of the country. At the same time, the maximum possible service time limit of 500 OHL, put into operation in the middle of the last century, can be increased from 50 to 70-80 years. After that, the main structural elements of the 500 kV OHL should be completely replaced, which will be a large scientific and technical problem from the standpoint of reliability of the operating modes of the country’s united power system.