bluuebunny/crossref_metadata_2025 huggingface dataset:
Microhardness Indentation Studies of 2‐4‐6 Trinitrotoluene
Authors: Gallagher Hugh G. , Sherwood John N. , Vrcelj Ranko M.
Published: October 2021

The microhardness of the {001} faces of 2‐4‐6 trinitrotoluene crystals has been investigated using both Vickers and Knoop indentation methods. The Vickers hardness number was found to be 22.5 kg mm−2 independent of crystal orientation and perfection. At ambient temperatures (∼20 °C) the Knoop hardness number varied between 20.5 kg mm−2 and 24.0 kg mm−2 with crystal orientation. At higher temperature (50 °C) the Knoop hardness anisotropy curve retained its shape, although the overall hardness decreased by 10 %. We interpret this change as reflecting a simple temperature dependant loosening of the crystal lattice rather than any change in deformation mechanism. No variation of Knoop hardness was evident with changing load. The hard direction was [010] and the soft [100]. The dominant operative slip system was defined to be {001}[010].
Glycoforms of human prostate‐specific membrane antigen (PSMA) in human cells and prostate tissue
Authors: Yuan Wei , Liu Baoqin , Sanda Miloslav , Wei Renhuizi , Benicky Julius , Novakova Zora , Barinka Cyril , Goldman Radoslav
Published: October 2021

Introduction

N‐glycosylation is a ubiquitous and variable posttranslational modification that regulates physiological functions of secretory and membrane‐associated proteins and the dysregulation of glycosylation pathways is often associated with cancer growth and metastasis. Prostate‐specific membrane antigen (PSMA) is an established biomarker for prostate cancer imaging and therapy.

Methods

Mass spectrometry was used to analyze the distribution of the site‐specific glycoforms of PSMA in insect, human embryonic kidney, and prostate cancer cells, and in prostate tissue upon immunoaffinity enrichment.

Results

While recombinant PSMA expressed in insect cells was decorated mainly by paucimannose and high mannose glycans, complex, hybrid, and high mannose glycans were detected in samples from human cells and tissue. We noted an interesting spatial distribution of the glycoforms on the PSMA surface—high mannose glycans were the dominant glycoforms at the N459, N476, and N638 sequons facing the plasma membrane, while the N121, N195, and N336 sites, located at the exposed apical PSMA domain, carried primarily complex glycans. The presence of high mannose glycoforms at the former sequons likely results from the limited access of enzymes of the glycosynthetic pathway required for the synthesis of the complex structures. In line with the limited accessibility of membrane‐proximal sites, no glycosylation was observed at the N51 site positioned closest to the membrane.

Conclusions

Our study presents initial descriptive analysis of the glycoforms of PSMA observed in cell lines and in prostate tissue. It will hopefully stimulate further research into PSMA glycoforms in the context of tumor staging, noninvasive detection of prostate tumors, and the impact of glycoforms on physicochemical and enzymatic characteristics of PSMA in a tissue‐specific manner.
In vitro investigations into the roles of CYP450 enzymes and drug transporters in the drug interactions of zanubrutinib, a covalent Bruton's tyrosine kinase inhibitor
Authors: Zhang Heather , Ou Ying C. , Su Dan , Wang Fan , Wang Lai , Sahasranaman Srikumar , Tang Zhiyu
Published: October 2021

Zanubrutinib is a highly selective, potent, orally available, targeted covalent inhibitor (TCI) of Bruton's tyrosine kinase (BTK). This work investigated the in vitro drug metabolism and transport of zanubrutinib, and its potential for clinical drug–drug interactions (DDIs). Phenotyping studies indicated cytochrome P450 (CYP) 3A are the major CYP isoform responsible for zanubrutinib metabolism, which was confirmed by a clinical DDI study with itraconazole and rifampin. Zanubrutinib showed mild reversible inhibition with half maximal inhibitory concentration (IC50) of 4.03, 5.69, and 7.80 μM for CYP2C8, CYP2C9, and CYP2C19, respectively. Data in human hepatocytes disclosed induction potential for CYP3A4, CYP2B6, and CYP2C enzymes. Transport assays demonstrated that zanubrutinib is not a substrate of human breast cancer resistance protein (BCRP), organic anion transporting polypeptide (OATP)1B1/1B3, organic cation transporter (OCT)2, or organic anion transporter (OAT)1/3 but is a potential substrate of the efflux transporter P‐glycoprotein (P‐gp). Additionally, zanubrutinib is neither an inhibitor of P‐gp at concentrations up to 10.0 μM nor an inhibitor of BCRP, OATP1B1, OATP1B3, OAT1, and OAT3 at concentrations up to 5.0 μM. The in vitro results with CYPs and transporters were correlated with the available clinical DDIs using basic models and mechanistic static models. Zanubrutinib is not likely to be involved in transporter‐mediated DDIs. CYP3A inhibitors and inducers may impact systemic exposure of zanubrutinib. Dose adjustments may be warranted depending on the potency of CYP3A modulators.
FJU‐C28 inhibits the endotoxin‐induced pro‐inflammatory cytokines expression via suppressing JNK, p38 MAPK and NF‐κB signaling pathways
Authors: Jung Fang , Liu Jung‐Sen , Yang Shih‐Hsing , Tseng Hui‐Yun , Chou Shang‐Shing P. , Lin Jau‐Chen , Jow Guey‐Mei
Published: October 2021

Despite marked improvements in supportive care, the mortality rate of acute respiratory distress syndrome due to the excessive inflammatory response caused by direct or indirect lung injury induced by viral or bacterial infection is still high. In this study, we explored the anti‐inflammatory effect of FJU‐C28, a new 2‐pyridone‐based synthetic compound, on lipopolysaccharide (LPS)‐induced inflammation in vitro and in vivo models. FJU‐C28 suppressed the LPS‐induced mRNA and protein expression of iNOS, COX2 and proinflammatory cytokines. The cytokine protein array results showed that LPS stimulation enhanced the secretion of IL‐10, IL‐6, GCSF, Eotaxin, TNFα, IL‐17, IL‐1β, Leptin, sTNF RII, and RANTES. Conversely, the LPS‐induced secretion of RANTES, TIMP1, IL‐6, and IL‐10 was dramatically suppressed by FJU‐C28. FJU‐C28 suppressed the LPS‐induced expression of RANTES, but its parental compound FJU‐C4 was unable to diminish RANTES in cell culture media or cell lysates. FJU‐C28 blocked the secretion of IL‐6 and RANTES in LPS‐activated macrophages by regulating the activation of JNK, p38 mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB (NF‐κB). FJU‐C28 prevented the LPS‐induced decreases in lung function including vital capacity (VC), lung compliance (C chord), forced expiratory volume at 100 ms (FEV100), and forced vital capacity (FVC) in mice with LPS‐induced systemic inflammatory responses. FJU‐C28 also reduced neutrophil infiltration in the interstitium, lung damage and circulating levels of IL‐6 and RANTES in mice with systemic inflammation. In conclusion, these findings suggest that FJU‐C28 possesses anti‐inflammatory activities to prevent endotoxin‐induced lung function decrease and lung damages by down‐regulating proinflammatory cytokines including IL‐6 and RANTES via suppressing the JNK, p38 MAPK and NF‐κB signaling pathways.
The relationship between vancomycin AUC/MIC and trough concentration, age, dose, renal function in Chinese critically ill pediatric patients
Authors: Chen Jihui , Huang Xiaohui , Bu Shuhong , Chen Xiaoxiao , Zhou Jia , Liu Xinzhu , Guo Xiaowen , Li Lixia , Zhang Jian
Published: October 2021

To assess the pharmacokinetic parameters of vancomycin in Chinese critically ill pediatric patients, children treated with vancomycin, hospitalized in the intensive care unit were included. Samples to determine peak and trough serum concentrations were obtained on the third day of treatment. Half‐life was significantly longer in neonates and showed a decreasing trend in infants and children. In patients aged ≥1 month, AUC24/MIC ≥400 was achieved in 31.8% at the dose of 40 mg/kg/d, and in 48.7% at the dose of 60 mg/kg/d with an assumed MIC of 1 mg/L. Augmented renal clearance (ARC) was present in 27.3% of children, which was associated with higher vancomycin clearance and lower AUC values. A good correlation was observed between trough concentration and AUC24, and the trough concentration that correlated with AUC24 of 400 were varied according to the dosage regimens, 8.42 mg/L for 6‐hintervals, and 6.63 mg/L for 8‐h intervals. To conclude, vancomycin trough concentration that related to the AUC24 of 400 was much lower in critically ill children than that in adults. The dosage of 60 mg/kg/day did not enough for producing AUC24 in the range of 400–600 mg h/L in critically ill children, especially in those with ARC.
Temporary destudentification caused by COVID‐19: Motivations and effects on social relations in a Chilean university city
Authors: Prada‐Trigo José , Aravena‐Solís Natalia , Barra‐Vieira Pablo
Published: October 2021

The arrival of the coronavirus in 2020 brought major changes to education, with the rapid transition to online classes being the most significant. In the case of university students, the pandemic meant returning to their homes, which can be interpreted as a temporary destudentification. This manuscript analyses and interprets the motivations of university students from Temuco (Chile) to change their social relations and place of residence as a consequence of the COVID‐19 pandemic. Through a quantitative methodology that used more than 800 online surveys and a principal component analysis, it was concluded that the psychological well‐being and the security provided by the family were the main causes for changing accommodation; but a total of four main components related to material conditions, economic aspects, family and psychological and physical well‐being were identified. Similarly, although with the pandemic the family was the most reinforced dimension in terms of social relations, there were groups of students who were more connected to friends and colleagues or neighbours. The results point to a partial and temporary destudentification, explainable by the nature of the lease contract and the dependent role of the students with respect to the landlords.
Rutaecarpine alleviates acute pancreatitis in mice and AR42J cells by suppressing the MAPK and NF‐κB signaling pathways via calcitonin gene‐related peptide
Authors: Huang Haosu , Wang Meng , Guo Zimeng , Wu Di , Wang Hanyue , Jia Yan , Liu Honghui , Ding Junjie , Peng Jie
Published: October 2021

Acute pancreatitis (AP) is an acute inflammatory condition of the pancreas. Previous studies have shown that rutaecarpine (RUT), an important alkaloid component of Evodia rutaecarpa, exhibits certain protective effects against AP in rats by upregulating calcitonin gene‐related peptide (CGRP). However, the molecular mechanism of RUT in AP remains unknown. This study aimed to investigate the effects of RUT on cerulein‐induced AP in vivo and in vitro, and to explore the underlying molecular mechanisms. In cerulein/LPS‐treated wild‐type mice, but not CGRP gene knock‐out mice, RUT significantly ameliorated pancreatic inflammation by alleviating histopathological changes, reducing IL‐6 and TNF‐α levels, and increasing in IL‐10 levels. Moreover, RUT improved AP by suppressing the MAPK and NF‐κB signaling pathways. These effects were mostly mediated through CGRP. Cell‐based studies revealed that RUT significantly improved cell viability while suppressing the apoptosis of AR42J cells with cerulein‐induced AP, downregulating IL‐6 and TNF‐α, stimulating IL‐10 release, and inhibiting MAPK, NF‐κB, and STAT3 signaling activation, all in a CGRP‐dependent manner. RUT ameliorated cerulein/LPS‐induced AP inflammatory responses in mice and AR42J cells in a CGRP‐dependent manner and thus may represent a potential therapeutic option for AP patients. Our study provides valuable insights for AP drug development.
Scalable Creation of Deep Silicon‐Vacancy Color Centers in Diamond by Ion Implantation through a 1‐μm Pinhole
Authors: Hunold Lukas , Lagomarsino Stefano , Flatae Assegid M. , Kambalathmana Haritha , Sledz Florian , Sciortino Silvio , Gelli Nicla , Giuntini Lorenzo , Agio Mario
Published: October 2021

The controlled creation of quantum emitters in diamond represents a major research effort in the fabrication of single‐photon devices. Here, the scalable production of silicon‐vacancy (SiV) color centers in single‐crystal diamond by ion implantation up to m depths is presented. The lateral position of the SiV is spatially controlled by a 1‐m pinhole placed in front of the sample, which can be moved nanometer precise using a piezo stage. The initial implantation position is controlled by monitoring the ion beam position with a camera. Hereby, silicon ions are implanted at the desired spots in an area comparable to the diffraction limit. The role of ions scattered by the pinhole and the activation yield of the SiV color centers for the creation of single quantum emitters is also discussed.
An STM Perspective on Hexaborides: Surface States of the Kondo Insulator SmB6
Authors: Wirth Steffen , Schlottmann Pedro
Published: October 2021

Compounds within the hexaboride class of materials exhibit a wide variety of interesting physical phenomena, including polaron formation and quadrupolar order. In particular, SmB6 has recently drawn attention as it is considered a prototypical topological Kondo insulator. Evidence in favor of this concept, however, has proven experimentally difficult and controversial, partly because of the required temperatures and energy resolution. Here, a powerful tool is scanning tunneling microscopy (STM) with its unique ability to give local, microscopic information that directly relates to the one‐particle Green's function. Yet, STM on hexaborides is met with its own set of challenges. This article attempts to review the progress in STM investigations on hexaborides, with emphasis on SmB6 and its intriguing properties.
Hospitalised versus outpatient COVID‐19 patients' background characteristics and comorbidities: A systematic review and meta‐analysis
Authors: Mattey‐Mora Paola P. , Begle Connor A. , Owusu Candice K. , Chen Chen , Parker Maria A.
Published: October 2021

This study aimed to systematically assess COVID‐19 patient background characteristics and pre‐existing comorbidities associated with hospitalisation status. The meta‐analysis included cross‐sectional, cohort, and case‐series studies with information on hospitalisation versus outpatient status for COVID‐19 patients, with background characteristics and pre‐existing comorbidities. A total of 1,002,006 patients from 40 studies were identified. Significantly higher odds of hospitalisation were observed in Black individuals (OR = 1.33, 95% CI: 1.04–1.70), males (OR = 1.59, 95% CI: 1.43–1.76), and persons with current/past smoking (OR = 1.59, 95% CI: 1.34–1.88). Additionally, individuals with pre‐existing comorbidities were more likely to be hospitalised [asthma (OR = 1.22, 95% CI: 1.02–1.45), COPD (OR = 3.68, 95% CI: 2.97–4.55), congestive heart failure (OR = 6.80, 95% CI: 4.97–9.31), coronary heart disease (OR = 4.40, 95% CI: 3.15–6.16), diabetes (OR = 3.90, 95% CI: 3.29–4.63), hypertension (OR = 3.89, 95% CI: 3.34–4.54), obesity (OR = 1.98, 95% CI: 1.59–2.46) and renal chronic disease (OR = 5.84, 95% CI: 4.51–7.56)]. High heterogeneity and low publication bias among all factors were found. Age was not included due to the large variability in the estimates reported. In this systematic review/meta‐analysis for patients with COVID‐19, Black patients, males, persons who smoke, and those with pre‐existing comorbidities were more likely to be hospitalised than their counterparts. Findings provide evidence of populations with higher odds of hospitalisation for COVID‐19.
Spatio‐temporal sampled‐data control for delay reaction‐diffusion systems
Authors: Wang Yun‐Zhu , Wang Zhen , Wu Kai‐Ning , Wang Chen‐Xu
Published: October 2021

This article considers the exponential stabilization and performance for delay reaction‐diffusion systems (DRDSs), with spatial sampled‐data controller (SSDC) and spatio‐temporal sampled‐data controller (STSDC). Firstly, an SSDC is designed to stabilize the DRDSs. Using Lyapunov functional and Wirtinger's inequality technique, we obtain sufficient conditions to ensure the exponential stability of DRDSs. When there exist external disturbances, performance is considered and criteria are provided for the disturbed DRDSs, under the designed SSDC. Then, an STSDC is adopted for DRDSs. Time discrete item brings new difficulties for the analysis of the desired properties. To overcome these difficulties, a novel Lyapunov functional is constructed and Halaney's inequality is used. Moreover, the descriptor method is adopted. Under these techniques, delay‐dependent conditions are obtained to guarantee the exponential stability. The performance is also considered for the disturbed DRDSs under the designed STSDC. A Razumikhin‐type method is introduced together with the Lyapunov‐like functional. Sufficient conditions are presented to achieve performance for DRDSs with STSDC. Our theoretical results show that the spatial sampling interval does affect the desired properties, the shorter the spatial sampling interval, the easier to achieve the desired properties. Moreover, the time delay also influences the exponential stability of DRDSs, and smaller time delay is beneficial to the achievement of the stability. Finally, examples are given to illustrate the validity of results.
An analysis of the spatial evolution and influencing factors of rural settlements along the Shandong section of the Grand Canal of China
Authors: Huo Xiaolong , Xu Xiwei , Tang Yue , Zhang Zhen
Published: October 2021

Since 1980s, the weakening of the transportation function of the Grand Canal and rapid urbanisation have generated significant changes in the spatial pattern of rural settlements along the Grand Canal. Analysing the changing characteristics of this spatial pattern, and exploring the natural, social, and economic factors influencing these changes are key to understanding the regional spatial structure and development law, and grasping the degree of influence of these factors. This study selected approximately 13,000 rural settlements in 27 county‐level units in the Shandong section of the Grand Canal, from 1980 to 2018, as the research object. The Grand Canal's distance buffer zone is divided into canal‐side, near‐canal, far‐canal, and further‐canal settlements. The correlation model with the canal is constructed through the controlled experiment. The distribution, scale, and form of the settlement are analysed quantitatively by applying the change of gravity centre model (CGC), average nearest neighbour analysis (ANN), landscape metrics (LM), and other methods. The quantitative analysis of geographic detectors in spatial pattern differentiation factors shows the relative importance and interaction within them. This study indicates that the spatial distribution shows ‘large dispersion and small concentration’ and ‘small‐scale agglomeration’ characteristics. The larger the scale of the settlement expands, the more the number of settlements decreases. The closer the settlement nears the river, the more complex the shape clusters. The total output value of agriculture, forestry, animal husbandry, fisheries, the total power of agricultural machinery, and the effective irrigation area are the main influencing factors. The grain area and the per capita disposable income of rural residents are the main auxiliary influencing factors.
From site to system: Approaches for producing system‐wide estimates of fish habitat in large rivers
Authors: Robinson H. Eve , Henderson Mark J. , Perry Russell W. , Goodman Damon H. , Som Nicholas A.
Published: October 2021

Worldwide, many productive rivers are dam‐regulated and rely on flow management strategies that must balance support of ecological processes with human water use. One component of evaluating this balance is to understand ecological consequences of alternative flow management strategies, which has often been accomplished by coupling population dynamics models with models that relate streamflow to habitat availability and quality. Numerous methods assign habitat availability to locations within a river basin: These include fine‐scale field‐measured values that are extrapolated to other locations within the basin having similar physical characteristics or equation‐driven values created by functions of model‐predicted values of physical characteristics. The array of options for creating habitat models is evolving rapidly as high‐resolution remote‐sensing data becomes more accessible and computational capacity improves. Our objective was to identify trade‐offs among approaches that assign habitat relationships to large rivers and to create a decision support tool to supplement choices of extent and granularity. Using a selection of case studies that represent a breadth of scales and diverse trade‐offs, we demonstrate the need for a transparent process of data evaluation and assessment to determine the appropriate fit for model scope or context that best supports management needs and recognize sources of uncertainty. The structured approach proposed here aims at improving future model development and refine population dynamics models that inform the management of rivers.
The discrepancy of random rectangular matrices
Authors: Altschuler Dylan J. , Niles‐Weed Jonathan
Published: October 2021

A recent approach to the Beck–Fiala conjecture, a fundamental problem in combinatorics, has been to understand when random integer matrices have constant discrepancy. We give a complete answer to this question for two natural models: matrices with Bernoulli or Poisson entries. For Poisson matrices, we further characterize the discrepancy for any rectangular aspect ratio. These results give sharp answers to questions of Hoberg and Rothvoß (SODA 2019) and Franks and Saks (Random Structures Algorithms2020). Our main tool is a conditional second moment method combined with Stein's method of exchangeable pairs. While previous approaches are limited to dense matrices, our techniques allow us to work with matrices of all densities. This may be of independent interest for other sparse random constraint satisfaction problems.
Measuring shrinkage of undisturbed soil peds
Authors: Shockey Matthew C. , Stewart Ryan D. , Keim Richard F.
Published: October 2021

Methods to measure shrinkage curves typically either disturb natural aggregate structure or include difficult or slow volume measurement techniques. Additionally, most shrinkage curves are obtained by serial measurement of a few samples. We obtained shrinkage curves by collecting rapid, one‐off measurements of volume and moisture content for each of 200 undisturbed peds extracted from a field soil, taking measurements as peds slowly dried in the laboratory. The large sample size increased robustness of the shrinkage curve parameter estimates to noise generated by this rapid measurement technique, but a much smaller sample would have resulted in similar parameter estimates.
Advancing community‐based tourism approaches for the sustainable development of destinations
Authors: Mtapuri Oliver , Camilleri Mark Anthony , Dłużewska Anna
Published: October 2021

This contribution suggests that community‐based tourism (CBT) can create commercial and social value to destinations, local businesses as well as to residents. At the same time, it clarifies that CBT offers rich, immersive cultural experiences that can enhance the tourists' experiences when visiting different communities. It posits that sustainable CBT approaches can improve the local economic development (LED) of communities by reducing economic leakages from the tourism industry. It explains that there is scope for destination managers and tourism businesses to engage in sustainable tourism practices and to utilize local resources, in a strategic manner, in order to maximize linkages in their economy. In conclusion, this paper puts forward a theoretical model that clearly illustrates the business case to implement sustainable CBT strategies. It also implies that these strategies can ultimately result in opportunities for economic growth of tourism businesses and may increase the competitiveness of destinations, while safeguarding the environment and addressing their carrying capacities.
Definition of a new (Doniach‐Sunjic‐Shirley) peak shape for fitting asymmetric signals applied to reduced graphene oxide/graphene oxide XPS spectra
Authors: Moeini Behnam , Linford Matthew R. , Fairley Neal , Barlow Anders , Cumpson Peter , Morgan David , Fernandez Vincent , Baltrusaitis Jonas
Published: October 2021

The existence of asymmetry in X‐ray photoelectron spectroscopy (XPS) photoemission lines is widely accepted, but line shapes designed to accommodate asymmetry are generally lacking in theoretical justification. In this work, we present a new line shape for describing asymmetry in XPS signals that is based on two facts. First, the most widely known line shape for fitting asymmetric XPS signals that has a theoretical basis, referred to as the Doniach‐Sunjic (DS) line shape, suffers from a mathematical inconvenience, which is that for asymmetric shapes the area beneath the curve (above the x‐axis) is infinite. Second, it is common practice in XPS to remove the inelastically scattered background response of a peak in question with the Shirley algorithm. The new line shape described herein attempts to retain the theoretical virtues of the DS line shape, while allowing the use of a Shirley background, with the consequence that the resulting line shape has a finite area. To illustrate the use of this Doniach‐Sunjic‐Shirley (DSS) line shape, a set of spectra obtained from varying amounts of graphene oxide (GO) and reduced GO on a patterned, heterogeneous surface are fit and discussed.
A New Strategy for the Preparation of E Isomers of Hydrazones and Anil‐Like Compounds: Thermally Stimulated Isomerization of Z Isomers of Anions
Authors: Tisovský Pavol , Donovalová Jana , Sokolík Róbert , Horváth Miroslav , Gáplovský Anton
Published: October 2021

A new, simple method for the preparation of E‐isomers of hydrazones and anil‐like compounds from Z‐isomers of these compounds has been developed. In DMF, the Z‐isomers of these compounds in the presence of tetrabutylammonium fluoride (TBAF) or tetrabutylammonium acetate (TBAA) gave the corresponding N anions of the Z‐isomers, which are isomerized to the N anions of the E‐isomers even at room temperature. Upon addition of a protic solvent (H2O, or CH3OH) to this reaction mixture, the N anion of the E‐isomer was immediately quantitatively converted to the E‐isomer of the corresponding nonionic compound, which can be readily isolated by methods commonly used in the synthesis.
Elemental Sulfur‐Promoted Tandem One‐Pot Synthesis of Diverse 4H‐Pyrimido[2,1‐b]benzothiazoles
Authors: Mathavan Sivagami , Yamajala Rajesh B. R. D.
Published: October 2021

An elemental sulfur promoted strategy for the synthesis of a series of diverse 4H‐pyrimido[2,1‐b]benzothiazoles has been developed under metal and solvent‐free conditions. This methodology allows the facile and convenient synthesis of desired products in good to excellent yields. This process achieved broad substrate scope, inexpensive catalyst and mild reaction conditions.
Synthesis of Phthalazinones with Amino or Hydrazide Moiety as Corrosion Inhibitors of Low Carbon Steel in 0.5 M H2SO4
Authors: Abdullah Rokaia Safwat , El Nemr Ahmed , El‐Sakka Sahar S. A. , El‐Hashash Maher A. , Soliman Mohamed H.
Published: October 2021

[4‐(4‐methoxy‐3‐methyl‐5 amino phenyl)‐1(2H)‐phthalazinone (APP), and [4‐(4‐mehoxy‐3‐methyl phenyl)‐1‐oxo‐1H‐phthalaz‐2‐yl]acetic acid hydrazide (PPH) were synthesized as a novel independently corrosion inhibitor for carbon steel in 0.5 M H2SO4. Nuclear magnetic resonance, Fourier transform infrared and mass spectroscopy were used to validate the structure of the two anticorrosion compounds. The corrosion rate was studied by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization) and gravimetric techniques, which clarify that the average corrosion inhibition efficiency of APP and PPH are 86 and 89 %, respectively. Impedance measurements showed that corrosion processes on the surface of LCS are controlled by a charge transfer mechanism. The PPH compound has a greater inhibitory effect on corrosion of low carbon steel. The quantum chemical calculations of APP and PPH were studied using AM1, PM3, and DFT/B3LYP/31G. Moreover, both APP and PPH acted as mixed type corrosion inhibitors. Adsorption of APP and PPH on low carbon steel (LCS) surface was physisorption and best fit to Langmuir isotherm.
Deciphering Mechanism of Assembly of Keratin within Nanofibrous Matrix: Expanding the Horizon of Electrospun Polymer/Protein Composites
Authors: Kadirvelu Kavitha , Fathima Nishter Nishad
Published: October 2021

Keratin is unique due to its high cysteine content. This renders it with exceptional structural stability in native form, whereas in extracted form it makes them highly reactive. Hence keratin possesses higher capacity to assemble without stimulus, thus necessitating the study. The choice of extraction was limited to sulphitolysis and β‐mercaptoethanol (M‐KH) based procedures, as these extracts exist in different structural levels evidenced through Circular Dichroic studies. Thermally induced irreversible structural transition of M‐KH from α‐helix to β‐sheet has resulted in lowering moisture loss peak of β‐mercaptoethanol extract based mat (PVA‐M‐T) to 80.4 °C compared to 120.6 °C of neat PVA fibers and 92 °C of sulphitloysis extract based mat. This signals presence of increased free water content in PVA‐M‐T after crosslinking. This helped PVA‐M‐T retain sufficient elongation at break values (∼31 %) without compromising its strength (∼8.5 MPa). Also PVA‐M‐T with increased β‐sheet content along with cell binding sequences (RGD, LDV and EDS) resulted in better protein‐protein recognition and association thus favouring increased bioactivity.
Synthesis of 3,4,5‐Triarylcyclohexanones from Dienones and 2‐Methylquinolines Based on a [5+1] Annulation
Authors: Chen Jiewen , Wen Kangmei , Wu Yinrong , Deng Jie , Chen Hongyue , Yao Xingang , Tang Xiaodong
Published: October 2021

We reported here a cobalt‐catalyzed [5+1] annulation with 1,5‐diarylpenta‐1,4‐dien‐3‐ones and 2‐methylquinolines. 3,4,5‐Triarylcyclohexanones were furnished in moderate to good yields and excellent diastereoselectivity under simple reaction conditions. Moreover, we preliminarily studied anticancer activities of the obtained products in vitro by MTT {3‐(4,5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide} assay.
Firm partisan positioning, polarization, and risk communication: Examining voluntary disclosures on COVID‐19
Authors: Benton Richard A. , Cobb J. Adam , Werner Timothy
Published: October 2021

Research Summary

The COVID‐19 pandemic will rank among the greatest challenges many executives will have faced and not only due to the operational challenges it posed. Upon entering the U.S. context, the disease was immediately politically polarized, with clear partisan splits forming in risk perceptions of the disease unrelated to science. We exploit this context to examine whether firms' partisan positioning affects whether and how they communicate risk to their investors on a polarized public policy issue. To do so, we examine the covariation between firms' disclosure of COVID‐19 risks and the partisanship of their political giving. Our analysis of earnings call and campaign contribution data for the S&P 500 reveals a positive association between a firm's contributions to Democrats and its disclosure of COVID‐19 risks.

Managerial Summary

From its onset in the United States, attitudes toward and discourse around the COVID‐19 pandemic was heavily politicized and perceptions of the disease's risks were seen as more serious by Democratic‐identifying individuals than Republican identifiers. In this study, we examine whether this pattern also holds for U.S. publicly traded firms, who can also stake out a political position through their corporate political action committee campaign contributions. In analyses of earnings call transcripts from the first quarter of 2020, we show that the more Republican‐leaning (Democrat‐leaning) a firm's campaign contributions are, the less (more) likely it was to voluntarily disclose risks related to COVID‐19. We argue that these findings hold implications for parties interested in interpreting firm's risk disclosures on politically polarized issues.
Starch Capped Atomically Thin CuS Nanocrystals for Efficient Photothermal Therapy
Authors: Zheng Zhiyong , Yu Ping , Cao Huili , Cheng Mengyu , Zhou Thomas , Lee Li E. , Ulstrup Jens , Zhang Jingdong , Engelbrekt Christian , Ma Lixin
Published: October 2021

Photothermal therapy requires efficient plasmonic nanomaterials with small size, good water dispersibility, and biocompatibility. This work reports a one‐pot, 2‐min synthesis strategy for ultrathin CuS nanocrystals (NCs) with precisely tunable size and localized surface plasmon resonance (LSPR), where a single‐starch‐layer coating leads to a high LSPR absorption at the near‐IR wavelength 980 nm. The CuS NC diameter increases from 4.7 (1 nm height along [101]) to 28.6 nm (4.9 nm height along [001]) accompanied by LSPR redshift from 978 to 1200 nm, as the precursor ratio decreases from 1 to 0.125. Photothermal temperature increases by 38.6 °C in 50 mg L−1 CuS NC solution under laser illumination (980 nm, 1.44 W cm−2). Notably, 98.4% of human prostate cancer PC‐3/Luc+ cells are killed by as little as 5 mg L−1 starch‐coated CuS NCs with 3‐min laser treatment, whereas CuS NCs without starch cause insignificant cell death. LSPR modeling discloses that the starch layer enhances the photothermal effect by significantly increasing the free carrier density and blue‐shifting the LSPR toward 980 nm. This study not only presents a new type of photothermally highly efficient ultrathin CuS NCs, but also offers in‐depth LSPR modeling investigations useful for other photothermal nanomaterial designs.
Synergistic Dual‐Atom Molecular Catalyst Derived from Low‐Temperature Pyrolyzed Heterobimetallic Macrocycle‐N4 Corrole Complex for Oxygen Reduction
Authors: Samireddi Satyanarayana , Aishwarya V. , Shown Indrajit , Muthusamy Saravanakumar , Unni Sreekuttan M. , Wong Ken‐Tsung , Chen Kuei‐Hsien , Chen Li‐Chyong
Published: October 2021

A heterobimetallic corrole complex, comprising oxygen reduction reaction (ORR) active non‐precious metals Co and Fe with a corrole‐N4 center (PhFCC), is successfully synthesized and used to prepare a dual‐atom molecular catalyst (DAMC) through subsequent low‐temperature pyrolysis. This low‐temperature pyrolyzed electrocatalyst exhibited impressive ORR performance, with onset potentials of 0.86 and 0.94 V, and half‐wave potentials of 0.75 and 0.85 V, under acidic and basic conditions, respectively. During potential cycling, this DAMC displayed half‐wave potential losses of only 25 and 5 mV under acidic and alkaline conditions after 3000 cycles, respectively, demonstrating its excellent stability. Single‐cell Nafion‐based proton exchange membrane fuel cell performance using this DAMC as the cathode catalyst showed a maximum power density of 225 mW cm−2, almost close to that of most metal–N4 macrocycle‐based catalysts. The present study showed that preservation of the defined CoN4 structure along with the cocatalytic Fe–Cx site synergistically acted as a dual ORR active center to boost overall ORR performance. The development of DAMC from a heterobimetallic CoN4‐macrocyclic system using low‐temperature pyrolysis is also advantageous for practical applications.
3D Printed Scaffolds for Monolithic Aerogel Photocatalysts with Complex Geometries
Authors: Schreck Murielle , Kleger Nicole , Matter Fabian , Kwon Junggou , Tervoort Elena , Masania Kunal , Studart André R. , Niederberger Markus
Published: October 2021

Monolithic aerogels composed of crystalline nanoparticles enable photocatalysis in three dimensions, but they suffer from low mechanical stability and it is difficult to produce them with complex geometries. Here, an approach to control the geometry of the photocatalysts to optimize their photocatalytic performance by introducing carefully designed 3D printed polymeric scaffolds into the aerogel monoliths is reported. This allows to systematically study and improve fundamental parameters in gas phase photocatalysis, such as the gas flow through and the ultraviolet light penetration into the aerogel and to customize its geometric shape to a continuous gas flow reactor. Using photocatalytic methanol reforming as a model reaction, it is shown that the optimization of these parameters leads to an increase of the hydrogen production rate by a factor of three from 400 to 1200 µmol g−1 h−1. The rigid scaffolds also enhance the mechanical stability of the aerogels, lowering the number of rejects during synthesis and facilitating handling during operation. The combination of nanoparticle‐based aerogels with 3D printed polymeric scaffolds opens up new opportunities to tailor the geometry of the photocatalysts for the photocatalytic reaction and for the reactor to maximize overall performance without necessarily changing the material composition.
Topological Photonics on a Small Scale
Authors: Zhirihin Dmitry V. , Kivshar Yuri S.
Published: October 2021

The study of topological phases of light suggests novel opportunities for creating robust optical structures and on‐chip photonic devices which are immune against scattering losses and structural disorder. However, many recent demonstrations of topological effects in optics use structures with relatively large scales. Here, the physics and realization of topological photonics on small scales, with the dimensions often smaller or comparable with the wavelength of light, are discussed. The recent experimental demonstrations of small‐scale topological states based on arrays of resonant nanoparticles are highlighted and a novel photonic platform using higher‐order topological effects for creating subwavelength highly efficient topologically protected optical cavities is discussed. Special attention is paid to the recent progress on topological polaritonic structures and the paper concludes with the vision on the future directions of nanoscale topological photonics and its impact on other fields.
High‐Quality α‐FAPbI3 Film Assisted by Lead Acetate for Efficient Solar Cells
Authors: Xi Jiahao , Wang Hui , Yuan Jifeng , Yan Xiaoqin , Siffalovic Peter , Tian Jianjun
Published: October 2021

The α‐phase formamidinium lead triiodide (α‐FAPbI3)‐based perovskite solar cells (PSCs) exhibit potential high efficiency due to their narrow bandgap, but the fabrication of a stable α‐FAPbI3 film still is challenging. Herein, a strategy is devised to achieve a stable α‐FAPbI3 film, in which lead acetate (PbAc2) is added to the perovskite precursor solution. The Ac− ions are involved in the formation of the lead halide octahedra, which effectively promotes the entry of FA+ into the lead halide octahedra to stabilize the α‐phase of FAPbI3. Furthermore, the Ac− will gradually leave during the annealing process, thus the addition of PbAc2 cannot introduce other components in the FAPbI3. The crystallinity and crystal orientation of the perovskite films are also improved by the PbAc2 additive to obtain low trap density films, leading to an increase in charge carrier collection. The champion solar cell based on the α‐FAPbI3 film presented a power conversion efficiency (PCE) of 21.24% with negligible hysteresis. After 500 h of storage under ambient conditions, the devices still maintained more than 90% of their initial efficiency.
Using Ginkgo's memory accessor for improving the accuracy of memory‐bound low precision BLAS
Authors: Grützmacher Thomas , Anzt Hartwig , Quintana‐Ortí Enrique S.
Published: October 2021

The roofline model not only provides a powerful tool to relate an application's performance with the specific constraints imposed by the target hardware but also offers a graphic representation of the balance between memory access cost and compute throughput. In this work, we present a strategy to break up the tight coupling between the precision format used for arithmetic operations and the storage format employed for memory operations. (At a high level, this idea is equivalent to compressing/decompressing the data in registers before/after invoking store/load memory operations.) In practice, we demonstrate that a “memory accessor” that hides the data compression behind the memory access, can virtually push the bandwidth‐induced roofline, yielding higher performance for memory‐bound applications using high precision arithmetic that can handle the numerical effects associated with lossy compression. We also demonstrate that memory‐bound applications operating on low precision data can increase the accuracy by relying on the memory accessor to perform all arithmetic operations in high precision. In particular, we demonstrate that memory‐bound BLAS operations (including the sparse matrix‐vector product) can be re‐engineered with the memory accessor and that the resulting accessor‐enabled BLAS routines achieve lower rounding errors while delivering the same performance as the fast low precision BLAS.
Evaluating the semantic transparency of Guaraná: A domain‐specific language for enterprise application integration
Authors: Bocanegra Jose , Frantz Rafael Z. , Roos‐Frantz Fabricia , Basso Fabio P.
Published: October 2021

Guaraná domain‐specific language is aimed to design enterprise application integration models. Although the language has been broadly used in the industry and academy, the design of its graphical notation was based in the common sense and social opinion of its developers rather than theoretical principles and empirical evidence. Thus, Guaraná becomes as an option for studying, modifying, and improving its concrete syntax. In this article we conducted an experiment with 85 participants in order to evaluate the semantic transparency of the concrete syntax of Guaraná. The study concludes that the language is not found to be semantically immediate because most of the language constructs used in the graphical notation of Guaraná are not semantically immediate, that is, a novice reader is not able to infer their meaning from their appearance alone.
Fuzzy multicriteria model to support decision making during the selection process of teaching and research staff in higher education
Authors: Tadić Ivana , Marasović Branka , Jerković Ivana
Published: October 2021

Selecting human resources represents complex tasks and ultimately determines an organisation's future stability and development. High‐quality selection procedures serve as the basis for proper employee utilisation and individual career development, which generate organisational success. To be most effective, in addition to applicant competency in the field, decision makers use various selection techniques and tools. These are applied to reveal and distinguish applicants' characteristics, qualifications and competencies, as well as to predict their success and organisational contribution specified for each profession and position. The main aim of this paper is to develop a fuzzy multicriteria model based on the technique for order preference by similarity to ideal solution (TOPSIS) as support for decision making when teaching and research staff are selected for employment within higher education. The model is based on hierarchically structured selection criteria fortified by the different qualitative and quantitative nature of each criterion, as well as the influence of required experts' competencies. We apply this model in the higher education sector for selecting teaching and research staff in Croatia.
Strain Rate Dependence of Hot Tensile Behavior, Microstructure Evolution, and Fracture Mechanism of Lean Duplex Stainless Steel 2101
Authors: Deng Yue , Li Jingyuan , Li Wang , Gu Jinbo , Zhang Xinghai
Published: October 2021

To improve the hot workability of lean duplex stainless steel 2101 (LDX 2101), the effects of strain rate on the hot tensile behavior, microstructure evolution, and fracture mechanism of LDX 2101 are systematically studied. Results indicate that ferrite is softened by continuous dynamic recrystallization (CDRX) and austenite may start through a mechanism analogous to CDRX at the low strain rate of 0.1 s−1. A softening mechanism similar to the discontinuous dynamic recrystallization (DDRX) is observed both in ferrite and in austenite at the strain rate of 5 s−1. The main fracture mechanism is a void accumulation fracture mode. Cracks form and propagate into the ferrite due to the low softening degree of austenite at the strain rate of 0.1 s−1. As the strain rate increases to 5 s−1, the dynamic recrystallization behavior of austenite increases due to the accelerated accumulation of dislocations and the high storage energy. The microhardness and strain distribution difference between ferrite and austenite decreases, and the crack propagation trend weakens, thus improving the thermoplasticity. The findings are of great significance for understanding the thermoplasticity of LDX 2101 and other two‐phase alloys.
Confidence intervals that utilize sparsity
Authors: Kabaila Paul , Farchione David
Published: October 2021

We consider a linear regression model with orthogonal regressors and Gaussian random errors with known variance, in the low‐dimensional setting that the length of the regression parameter vector does not exceed the length of the response vector. We suppose that we have uncertain prior information that sparsity holds, that is, that many of the components of the regression parameter vector are zero. Our aim is to construct confidence intervals for the components of this vector with both the desired coverage probability and attractive expected length properties, particularly when sparsity holds. It is known that for fixed‐width confidence intervals centered on penalized maximum likelihood estimators, such as hard‐thresholding, LASSO and SCAD estimators, the achievement of the desired minimum coverage necessarily results in very unattractive expected length properties. We present confidence intervals, with data‐based widths, which achieve our aim. These confidence intervals dominate the usual confidence intervals with the same coverage probability, whenever the degree of sparsity exceeds a known value.
Model error and reliability of reinforced concrete beams in shear designed according to the Modified Compression Field Theory
Authors: Agarwal Ankit , Foster Stephen J. , Stewart Mark G.
Published: October 2021

Model error (or model uncertainty) were probabilistically characterized for modified compression field theory (MCFT) Simplified and General Method approaches using experimental databases that contained reinforced concrete (RC) beams having shear failures with and without stirrups (168 and 368 specimens, respectively). It was found that when compared to the design shear model currently used in ACI‐318, the General Method produced low model error variability indicating better consistency for the determination of shear strength. Structural reliabilities were then calculated for RC beams in shear designed to MCFT General Method (AASHTO LRFD, CSA A23.3‐14, AS3600‐2018) for a live‐to‐dead load ratio between 0 and 5, and for capacity reduction factor ϕ = 0.70, 0.75, and 0.80. It was concluded that the ϕ‐factor for shear failure for Australian standards can be increased from 0.70 to 0.75 for RC beams with stirrups, providing a 7.1% increase in the design shear capacity and contributing to sustainable design and reduction in greenhouse gas emissions due to more efficient usage of materials.