bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes of a novel alloplastic technique for external auditory canal repair in tympanomastoidectomy
Authors: LeClair Karissa L. , Bessen Sarah Y. , Rees Christiaan A. , Saunders James E.
Published: August 2020

Objective

To analyze surgical outcomes of a novel alloplastic reconstruction technique for partial external auditory canal (EAC) defects in tympanomastoidectomy.

Methods

Retrospective study of 51 patients with cholesteatoma who underwent repair of partial EAC defects during tympanomastoidectomy at a tertiary referral center over 8 years. Nineteen patients were treated with a novel alloplastic graft technique using hydroxyapatite cement and bone pâté for EAC repair. Thirty‐two patients treated with traditional cartilage repair of the EAC served as a control group. The primary outcomes measured were postoperative cholesteatoma recurrence rates, infection rates, and mean air‐bone gap (ABG).

Results

Twenty of the 51 cases (39.2%) were revision surgeries for cholesteatoma recidivism, with a greater proportion of revision surgeries in the alloplastic group (57.9% vs 28.1%, P = .04). There was no significant difference in postoperative cholesteatoma recurrence (P = 1.00) or infection rates (P = .64) between the two techniques, with the alloplastic group experiencing slightly lower rates of recurrence (36.8%) and infection (5.3%) than cartilage repair (37.5% recurrence, 12.5% infection). Mean postoperative ABGs were comparable between the alloplastic (21.5 dB) and cartilage group (26.0 dB, P = .10).

Conclusions

Composite alloplastic and bone pâté reconstruction is an effective technique to repair partial EAC defects in tympanomastoidectomy, with comparable postoperative hearing outcomes and no increased risk of cholesteatoma recurrence or infection compared to traditional cartilage repair. Recidivism rates were relatively high in both groups, likely due to the high rate of revision surgeries and aggressive nature of cholesteatoma within the cohort.

Level of Evidence

Level 3B.
The role of human capital on the performance of manufacturing firms in Bangladesh
Authors: Shamsuzzoha  , Tanaka Makoto
Published: August 2020

The efficiency determinants of manufacturing firms in developing countries have received increasing attention over the past few decades. This study examines the role of top managers' human capital and other exogenous determinants of the efficiency of manufacturing firms in Bangladesh by using heteroscedastic single‐step stochastic frontier analysis. We find that general human capital represented by educational qualification and specific human capital formed by work specific experience show different ways of impact on firm performance. Specifically, education has both a direct impact on firm outputs and an indirect impact as an efficiency determinant, whereas experience affects only technical efficiency.
Time‐lagged inverse‐distance weighting for air temperature analysis in an equatorial urban area (Guayaquil, Ecuador)
Authors: Quagliolo Carlotta , Pezzoli Alessandro , Ignaccolo Rosaria , Davila José Luis Santos
Published: August 2020

It is well known that sudden variations of air temperature have the potential to cause severe impacts on human health. Therefore, it becomes necessary to provide information capable of quantifying the severity of the problem, considering that the continuous increase of temperature due to global warming and urban development will cause more intense effects in heavily populated areas. Due to its geographical location and local characteristics, Ecuador, a country located on the western coast of South America, is characterized by a high vulnerability to climatic extremes. The present research develops an evaluation of urban climate change effects through the analysis of extreme temperature indices using four meteorological stations situated in the city of Guayaquil (southwest Ecuador). Since the available data are not adequate for extreme temperature indices criteria, it was necessary to employ an infilling method for times series in an innovative way that can be applicable at the small scale. Thus, a cross‐correlation‐enhanced inverse distance weighting (CC‐IDW) method was proposed. The method entails a spatial interpolation based on data of urban stations situated outside of Guayaquil by taking into account cross‐correlation among times series at precise lags that leads to an improvement in the way of estimating the missing values. Subsequently, a homogeneity test, data quality control and the calculation of extreme temperature indices chosen from those proposed by the World Meteorological Organization (WMO) were implemented. The results show that there is a general tendency of warming with quite homogenous temperatures for all considered stations. However, it should be recognized that the climate pattern of this region is strongly modulated by the El Niño Southern Oscillation (ENSO) cycle. Only for two extreme indices: the highest maximum temperature (TXx) and the warm days (TX90p), are the resulting trend co‐efficients statistically significant. The study suggests a deteriorated climatic condition due to heat stress that warrants further study using the available database for the city of Guayaquil.
A novel homozygous variant in MICOS13/QIL1 causes hepato‐encephalopathy with mitochondrial DNA depletion syndrome
Authors: Kishita Yoshihito , Shimura Masaru , Kohda Masakazu , Akita Masumi , Imai‐Okazaki Atsuko , Yatsuka Yukiko , Nakajima Yoko , Ito Tetsuya , Ohtake Akira , Murayama Kei , Okazaki Yasushi
Published: August 2020

Background

Mitochondrial DNA depletion syndrome (MTDPS) is part of a group of mitochondrial diseases characterized by a reduction in mitochondrial DNA copy number. Most MTDPS is caused by mutations in genes that disrupt deoxyribonucleotide metabolism.

Methods

We performed the whole‐exome sequencing of a hepato‐encephalopathy patient with MTDPS and functional analyses to determine the clinical significance of the identified variant.

Results

Here, whole‐exome sequencing of a patient presenting with hepato‐encephalopathy and MTDPS identified a novel homozygous frameshift variant, c.13_29del (p.Trp6Profs*71) in MICOS13. MICOS13 (also known as QIL1, MIC13, or C19orf70) is a component of the MICOS complex, which plays crucial roles in the maintenance of cristae junctions at the mitochondrial inner membrane. We found loss of MICOS13 protein and fewer cristae structures in the mitochondria of fibroblasts derived from the patient. Stable expression of a wild‐type MICOS13 cDNA in the patients fibroblasts using a lentivirus system rescued mitochondrial respiratory chain complex deficiencies.

Conclusion

Our findings suggest that the novel c.13_29del (p.Trp6Profs*71) MICOS13 variant causes hepato‐encephalopathy with MTDPS. We propose that MICOS13 is classified as the cause of MTDPS.
A class of inverse problems for evolution equations with the Riemann‐Liouville derivative in the sectorial case
Authors: Fedorov Vladimir E. , Nagumanova Anna V. , Avilovich Anna S.
Published: August 2020

We investigate the unique solvability of a class of linear inverse problems with a time‐independent unknown coefficient in an evolution equation in Banach space, which is resolved with respect to the fractional Riemann‐Liouville derivative. We assume that the operator in the right‐hand side of the equation generates a family of resolving operators for the corresponding homogeneous equation, which is exponentially bounded and analytic in a sector containing the positive semiaxis. It is shown that the inverse problem is well‐posed with respect to the graph norm of the generating operator only. A well‐posedness criterion is found. The obtained abstract results are applied to the unique solvability study of an inverse problem for a class of time‐fractional partial differential equations. An example, in particular, shows that in the case of an unbounded generating operator, the inverse problem can be ill‐posed with respect to the norm of the whole space.
Time‐resolved coded structured light for 3D measurement
Authors: Ye Jing , Zhou Changhe
Published: August 2020

Corresponding points matching is the fundamental computational task underlying stereo vision, and the key issue in making stereo vision practical is to find the most suitable algorithm to quickly match corresponding points, which leads to 3D reconstruction. In this paper, we proposed a new encoding strategy of dot‐pattern structured light based on temporal modulated vertical cavity surface emitting laser (VCSEL) array, which is especially suitable for the dot projector in miniaturized devices for stereo vision. Although VCSEL has been used in Apple's iPhone X for dot projector, the time dimension information is not used. VCSEL array has the capability of controlling each light source separately, so we can encode the information of time dimension into the structured light, which improves the stereo‐matching accuracy and simplifies the algorithm. In addition, compared to the temporal random speckle structured light method, this time‐resolved coded dot‐pattern structured light method greatly reduces the number of frames of projecting images required, which has great significance for real‐time 3D reconstruction in practical applications. Therefore, the method proposed here could be of high interest for its potentials in 3D measurement in mobile phones and other miniaturized devices. The proof‐of‐principle experiment results verify the computational efficiency and matching accuracy of the method.
Performance of a new star‐bar phantom designed for MTF calculations in x‐ray imaging systems
Authors: González‐López Antonio , Campos‐Morcillo Pedro‐Antonio , Vera‐Sánchez Juan Antonio , Ruiz‐Morales Carmen
Published: August 2020

Purpose

A new phantom, designed and manufactured for modulation transfer function (MTF) calculations is presented in this work. The phantom has a star‐bar pattern and is manufactured in stainless steel. Modulation transfer function determinations are carried out with the new phantom and with an edge phantom to compare their performance and to compare them with previous theoretical predictions.

Methods

The phantoms are imaged in an x‐ray imaging system using different beam qualities and different entrance air KERMA. Methods, previously developed for synthetic images and simulations, are adapted to real measurements, solving practical implementation issues.

Results

In the case of the star‐bar, in order to obtain optimal MTF determinations it is necessary to accurately determine the center of the pattern. Also, to avoid underestimates in MTF calculations, the length in pixels of each of the scanning circumferences must be an integer multiple of the number of cycles in the pattern. Both methods, star‐bar and edge, give similar mean values of the MTF in all cases analyzed. Also, the dependence with frequency of the experimental MTF standard deviation (SD) agrees with the theoretical expressions presented in previous works. In this regard, the precision is better for the star‐bar method than for the edge and differences in precision between both methods are higher for the lowest beam quality.

Conclusions

The star‐bar phantom can be used for MTF determinations with the advantage of having an improved precision. However, precision is reduced when the radiation quality increases. This fact suggests that, for the highest beam qualities, materials with an attenuation coefficient greater than that of steel should be used to manufacture the phantom.
De‐anonymizing Ethereum blockchain smart contracts through code attribution
Authors: Linoy Shlomi , Stakhanova Natalia , Ray Suprio
Published: August 2020

Blockchain users are identified by addresses (public keys), which cannot be easily linked back to them without out‐of‐network information. This provides pseudo‐anonymity, which is amplified when the user generates a new address for each transaction. Since all transaction history is visible to all users in public blockchains, finding affiliation between related addresses undermines pseudo‐anonymity. Such affiliation information can be used to discriminate against addresses linked with undesired activities or can lead to de‐anonymization if out‐of‐network information becomes available.

In this work, we propose an approach to undermine pseudo‐anonymity of blockchain transactions by linking together addresses that were used to deploy smart contracts, which were produced by the same authors. In our approach, we leverage stylometry techniques, widely used in the social science field for attribution of literary texts to their corresponding authors. The assumption underlying authorship attribution is the existence of a distinctive writing style, unique to an author and easily distinguishable from others. Drawing an analogy between literary text and smart contracts' source code, we explore the extent to which unique features of source code and byte code of Ethereum smart contracts can represent the coding style of smart contract developers. We show that even a small number of representative features leads to a sufficiently high accuracy in attributing smart contracts' code to its deployer's address. We further validate our approach on real‐world scammers' data and Ponzi scheme‐related contracts. Additionally, we provide an algorithm to extract distinctly contributing features per an entire dataset or per specific authors. We use this algorithm to extract and explore such features in our dataset and in the Ponzi scheme‐related dataset.
A DEM‐based method for predicting the wear evolution of structural boundary composed of spherical boundary elements
Authors: Fang Z.Q. , Hu L. , Peng S.L. , Yi J.G. , Du J.
Published: August 2020

In the discrete element method (DEM) simulation for wear prediction, structural boundary is now represented extensively by triangular meshes with high resolution, which brings a huge computational cost. A DEM‐based method for predicting the wear evolution of structural boundary has been developed for computational efficiency. The structural boundary subjected to wear is represented by the spherical boundary elements in the DEM simulation in combination with the inside triangles and fitting curved surface in wear prediction. Wear prediction is performed through a series of evolution steps. In each evolution step, the collision energies by particles at structural boundary are collected via the DEM simulation and assigned to the boundary elements. Then, the volume losses of structural boundary are predicted across each relevant boundary element. Finally, the new geometry of structural boundary in response to wear is described by moving the boundary elements along the depths of wear individually. Through converting the contact detection between structural boundary and particles into between spherical boundary elements and particles, our method greatly reduces the computational cost in the DEM simulation. Through two numerical tests, our method has been verified to be an efficient and accurate method for the wear prediction of structural boundaries with different resolutions.
A Haar wavelet collocation approach for solving one and two‐dimensional second‐order linear and nonlinear hyperbolic telegraph equations
Authors: Asif Muhammad , Haider Nadeem , Al‐Mdallal Qasem , Khan Imran
Published: August 2020

We have developed a new numerical method based on Haar wavelet (HW) in this article for the numerical solution (NS) of one‐ and two‐dimensional hyperbolic Telegraph equations (HTEs). The proposed technique is utilized for one‐ and two‐dimensional linear and nonlinear problems, which shows its advantage over other existing numerical methods. In this technique, we approximated both space and temporal derivatives by the truncated Haar series. The algorithm of the method is simple and we can implement easily in any other programming language. The technique is tested on some linear and nonlinear examples from literature. The maximum absolute errors (MAEs), root mean square errors (RMSEs), and computational convergence rate are calculated for different number of collocation points (CPs) and also some 3D graphs are also drawn. The results show that the proposed technique is simply applicable and accurate.
Centring Indigenous knowledge systems to re‐imagine conservation translocations
Authors: Rayne Aisling , Byrnes Greg , Collier‐Robinson Levi , Hollows John , McIntosh Angus , Ramsden Mananui , Rupene Makarini , Tamati‐Elliffe Paulette , Thoms Channell , Steeves Tammy E.
Published: August 2020

Conservation translocations—particularly those that weave diverse ways of knowing and seeing the world—promise to enhance species recovery and build ecosystem resilience. Yet, few studies to date have been led or co‐led by Indigenous peoples; or consider how centring Indigenous knowledge systems can lead to betterconservation translocation outcomes.

In this Perspective, as Indigenous and non‐Indigenous researchers and practitioners working in partnership in Aotearoa New Zealand, we present a novel framework for co‐designing conservation translocations that centre Indigenous peoples and knowledge systems through Two‐Eyed Seeing.

We apply this framework to Aotearoa New Zealand's threatened and underprioritized freshwater biodiversity. In particular, we highlight the co‐development of conservation translocations with Te Kōhaka o Tūhaitara and Te Nohoaka o Tukiauau that are weaving emerging genomic approaches into mātauraka Māori (Māori knowledge systems), including customary practices, processes and language.

We envision the Two‐Eyed Seeing framework presented here will provide a critical point of reference for the co‐development of conservation translocations led or co‐led by Indigenous peoples elsewhere in the world to build more resilient biocultural heritage.

A freePlain Language Summarycan be found within the Supporting Information of this article.
The affiliative role of empathy in everyday interpersonal interactions
Authors: Ringwald Whitney R. , Wright* Aidan G.C.
Published: August 2020

Empathy theoretically serves an affiliative interpersonal function by satisfying motives for intimacy and union with others. Accordingly, empathy is expected to vary depending on the situation. Inconsistent empirical support for empathy’s affiliative role may be because of methodology focused on individual differences in empathy or differences between controlled experimental conditions, which fail to capture its dynamic and interpersonal nature. To address these shortcomings, we used ecological momentary assessment to establish typical patterns of empathy across everyday interactions. Associations among empathy, affect, and interpersonal behaviour of self and interaction partner were examined in a student sample ( N = 330), then replicated in a preregistered community sample ( N = 279). Multilevel structural equation modelling was used to distinguish individual differences in empathy from interaction-level effects. Results show that people are more empathetic during positively valenced interactions with others perceived as warm and when expressing warmth. By confirming the typically affiliative role of empathy, existing research to the contrary can be best understood as exceptions to the norm.
A child in pain: A psychologist’s perspective on changing priorities in scientific understanding and clinical care
Authors: Craig Kenneth D.
Published: August 2020

My research and clinical career followed a trajectory of increasing appreciation for the importance of social factors as determinants of pain experience and expression. The social contexts of children’s lives determine whether infants and children are exposed to pain, how socialization in family and ethnocultural contexts lead to pain as a social experience, comprised of thoughts and feelings as well as sensory input, how others shape pain experience and expression, less so for automatic/reflexive features than purposeful representations, and how other's appraisals of children’s pain reflect the observer's unique background and capacities for intervening in the child’s interests. A greater understanding of the social dimensions of pain, as reflected in the social communication model of pain, would support innovation of psychological and social interventions.
Effects of the functional groups amino and nitro on the reactivity of benzoxazoles and comparison with homologous benzothiazoles
Authors: Silva Ana L.R. , Ribeiro da Silva Maria D.M.C.
Published: August 2020

The energetic study of 2‐aminobenzoxazole (ABO) and 2‐methyl‐6‐nitrobenzoxazole (MNBO) has been developed using experimental and computational tools. The enthalpies of combustion, of fusion, and of sublimation of these compounds were measured by static‐bomb combustion calorimetry, differential scanning calorimetry, and Calvet microcalorimetry drop‐technique and/or the Knudsen‐effusion method. Additionally, we calculated the gas‐phase standard molar enthalpies of formation of these compounds, as well as of 2‐methyl‐6‐nitrobenzothiazole (MNBT), through high level ab initio calculations, at the G3(MP2)//B3LYP level of theory. Furthermore, the energetic effects associated with the presence of the amino and nitro groups on the core of benzoxazole or benzothiazole molecules were also evaluated, as well as stabilizing electronic interactions occurring in the molecules. The latter were investigated through Natural Bonding Orbital (NBO) of the corresponding wave functions. Finally, the thermodynamic stability of the titled compounds was evaluated and a comparison with their sulfur heteroanalogs was achieved. In the gaseous phase, the oxygen derivatives exhibit the lowest tendency to decompose into their constituent elements at standard conditions.
Synthesis of amphiphilic block copolymer using trimethylene carbonate bearing oligo(ethylene glycol) and investigation of thin film including cilostazol
Authors: Nobuoka Hiroaki , Nagasawa Masakazu , Chanthaset Nalinthip , Yoshida Hiroaki , Haramiishi Yoshiaki , Ajiro Hiroharu
Published: August 2020

To prepare a thin film, the block copolymer poly(TMCM‐MOE3OM)‐b‐PTMC was prepared with different segment ratios of hydrophilic moiety. The glass transition temperature of poly(TMCM‐MOE3OM)‐b‐PTMC decreased as the content of TMCM‐MOE3OM increased as expected, and it was confirmed that the graft oligo(ethylene glycol) (OEG) affected intermolecular interaction. The polymers grafted with OEG showed a thermoresponsive property, which can be expected to be applied to materials triggered by temperature. A thin film was prepared by mixing block copolymer and cilostazol as a drug, and the distribution of cilostazol was observed. It was confirmed that cilostazol was uniformly distributed on the thin film and that local sustained release could be avoided at the time of elution. The eluting behavior of the thin film from the substrate was apparently affected on the segment ratio of the block copolymer. When the thin film was immersed in PBS, the eluting rate increased as the segment ratio of TMCM‐MOE3OM in the block copolymer increased. As a result, it is possible to control the eluting rate by changing the ratio of the hydrophilicity and the hydrophobicity of the block copolymer, contributing to the creation of a new coating material containing cilostazol.
Combustion Properties of Composite Propellants Based on Two Kinds of Polyether Binders and Different Oxidizers
Authors: Gong Li , Li Jianmin , Li Yuping , Yang Rongjie
Published: August 2020

Two kinds of solid propellants based on propargyl‐terminated ethylene oxide‐tetrahydrofuran copolyether (PTPET) and ethylene oxide‐tetrahydrofuran copolyether (PET) were prepared with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), ammonium perchlorate (AP) and aluminum (Al), respectively. The order of burning rates for PET+RDX, PTPET+RDX and PET+RDX+Cu−B propellants: PTPET+RDX > PET+RDX > PET+RDX+Cu−B. Their pressure exponents are also similar when the pressure is higher than 7 MPa. The combustion residue of PET+RDX and PET+RDX+Cu−B propellants show a loose structure and there are many bright particles distributed in its flame zone. The combustion residue of PTPET+RDX propellant shows a dense structure and its flame is uniform. The burning rates of PET+AP+Cu−B propellant is between the burning rates of PET+AP and PTPET+AP propellants at the same pressure. Their flame shape is similar. The burning rates of PET+AP+Al+Cu−B propellant is also between the burning rates of PET+AP+Al and PTPET+AP+Al propellants at the same pressure. The combustion flame of PET+AP+Al propellant differs greatly in direction and shape at different time. The combustion flame of PTPET+AP+Al and PET+AP+Al+Cu−B become almost identical in shape and direction at different time. These results show that the curing catalyst Cu−B of PTPET propellant plays a catalytic role in combustion.
FEST – New Procedure for Evaluation of Sensitivity Experiments
Authors: Selesovsky Jakub , Pelikan Vojtech , Schuster Jaroslav , Janovský Břetislav , Matyáš Robert
Published: August 2020

The sensitivity of energetic materials to initiating stimuli is one of the tests with binary response. Usually, there is not a single sharp boundary between energy levels causing initiation and not causing initiation. Instead, there is an interval of energies causing the initiation with certain probability, called the sensitivity curve. In the past, various methods were developed to determine the whole sensitivity curve, or its important points (e. g. Bruceton staircase, Robbins‐Monroe, Langlie, Probit analysis, or Neyer'sD‐optimal test, 3pod). All these methods, despite frequently used, have their limitations. We would like to introduce the new method/algorithm, called FEST (Fast and Efficient Sensitivity Testing), for the determination of a sensitivity curve. The sensitivity curve is represented by the cumulative distribution function for a lognormal distribution. The calculation of the level for the next shot is similar to Neyer's approach in the beginning of the test procedure. Later, after the overlap is reached and therefore unique maximum likelihood estimates for μ and σ exist, the next shot level is calculated from these parameters using two user‐defined constants. These constants can be used to shift the levels of testing into the area of interest of the sensitivity curve. In this article, the algorithm is introduced, its convergence to real values is supported by simple Monte Carlo simulations, and a real life example (determination of sensitivity to electrostatic discharge for a pyrotechnic mixture) is presented.
Flexible bivariate correlated count data regression
Authors: Ma Zichen , Hanson Timothy E. , Ho Yen‐Yi
Published: August 2020

Multivariate count data are common in many disciplines. The variables in such data often exhibit complex positive or negative dependency structures. We propose three Bayesian approaches to modeling bivariate count data by simultaneously considering covariate‐dependent means and correlation. A direct approach utilizes a bivariate negative binomial probability mass function developed in Famoye (2010,Journal of Applied Statistics). The second approach fits bivariate count data indirectly using a bivariate Poisson‐gamma mixture model. The third approach is a bivariate Gaussian copula model. Based on the results from simulation analyses, the indirect and copula approaches perform better overall than the direct approach in terms of model fitting and identifying covariate‐dependent association. The proposed approaches are applied to two RNA‐sequencing data sets for studying breast cancer and melanoma (BRCA‐US and SKCM‐US), respectively, obtained through the International Cancer Genome Consortium.
Mesoporous Magnetite Nanoclusters as Efficient Nanocarriers for Paclitaxel Delivery
Authors: Shima  , Damodaran P.
Published: August 2020

This manuscript report the facile and cost‐effective fabrication of a targeted drug delivery system based on mesoporous magnetite (Fe3O4) nanoclusters. A simple one‐pot solvothermal method was followed for the synthesis of mesoporous Fe3O4 nanoclusters having average cluster size of ∼120 nm. As‐synthesized Fe3O4 nanoclusters exhibited excellent water dispersibility and superparamagnetism in conjunction with fast magnetic responsiveness. The anticancer drug, paclitaxel (PTX) was used as the model drug to investigate the applicability of as‐prepared mesoporous Fe3O4 nanoclusters for drug delivery applications. Successful loading of PTX into Fe3O4 nanoclusters was confirmed by Fourier‐transform infrared (FT‐IR) spectroscopy and drug loading capacity was estimated by thermogravimetric analysis (TGA). An efficient loading capacity of 17 % was achieved for PTX in the present study. The in vitro release of PTX was higher in acidic pH compared to physiological pH. As the extracellular pH of cancer cells is more acidic than that of normal cells, mesoporous Fe3O4 nanocluster‐based drug delivery vehicles can reduce the undesired release of PTX in blood circulation during the delivery process (at physiological pH) and can enhance the drug release inside the tumour cells. The results demonstrate that Fe3O4 nanoclusters developed in the present study are potential drug delivery systems
Synthesis and Application of Siloles: From the Past to Present
Authors: Santra Soumava
Published: August 2020

Heterocyclic compounds in particular siloles in which a carbon atom has been replaced by an isovalent silicon atom, has gained wide attention recently. Due to their unique and interesting electronic and aggregation‐induced emmision properties, they found practical application in many areas. The properties of siloles depend upon the nature of subsituents present on the ring. Therefore, the synthetic methods and strategies continued to evolve since their first synthetic report. The advances in the synthesis of siloles, mechanistic details, substituents effect and applications have been discussed in this review.
Bi(III) Complexes Containing Dithiocarbamate Ligands: Synthesis, Structure Elucidation by X‐ray Diffraction, Solid‐State 13C/15N NMR, and DFT Calculations
Authors: Gowda Vasantha , Sarma Bipul , Larsson Anna‐Carin , Lantto Perttu , Antzutkin Oleg. N.
Published: August 2020

We report on syntheses, characterisation by nuclear magnetic resonance (NMR) spectroscopy, X‐ray diffraction (XRD) measurements, and density functional theory (DFT) calculations of electronic/molecular structure and NMR chemical shifts of complexes of Bi(III), having the molecular formulae: [Bi{S2CN(C2H5)2)}3] (1), [Bi{S2CN(C2H5)2)}2(C12H8N2)NO3)] (2), and [Bi2{S2CN(CH2)5}6
H2O] (3). The powder XRD patterns of complexes (1) and (2) resembled the corresponding calculated powder XRD patterns for previously reported single crystal structures. Single crystal XRD structure of complex (3), reported in this work, adopted an orthorhombic system with a space group Pbca with a=10.9956(3) Å, b=27.7733(8) Å, c=35.1229(10) Å and α=β=γ=90°. The experimental solid‐state 13C/15N NMR data of the complexes (1)‐(3) were in accord with their X‐ray single crystal structures. The unit cell of the complex (3) shows a weak supramolecular Bi
S interaction leading to the formation of a non‐centrosymmetric binuclear molecule [Bi2{S2CN(CH2)5}6
H2O], which displays structural inequivalence in both 13C/15N NMR, and XRD data. Assignments of resonance lines in solid‐state 13C/15N NMR spectra of complexes (1)‐(3) were assisted by chemical shift calculations using periodic DFT methods. The findings of the present multidisciplinary approach will contribute in designing molecular models and further understanding of the structures and properties of (diamagnetic) metal complexes, including heavy metal ones.
Direct Electrochemistry and Sensitive Detection of Guanosine on Nanopolymeric Surfaces Bearing Boronic Acid Groups
Authors: Kuralay Filiz , Gürsoy Taner
Published: August 2020

This paper describes the use of novel boronic acid containing polymeric surfaces for following improved direct electrochemistry and highly sensitive and selective electrochemical detection of guanosine. Effective and robost boronic acid containing electroactive polymeric layers based on poly(3‐aminophenylboronic acid) (PAPBA) in the existence of a convenient nanomaterial (multi‐walled carbon nanotubes, MWCNTs) were fabricated onto graphite surfaces with a simple and reproducible single‐step electro‐fabrication method for the first time. So‐formed electrodes were then utilized for direct electrochemistry of guanosine and determination of guanosine. The electrode presented a linearity to guanosine from 1 μM to 120 μM and the detection limit was calculated as 0.14 μM (n=3). It was feasible to differentiate guanine and guanosine with a good peak separation value of 0.31 V. Furthermore, analytical performance of this novel electrode was compared with the performances of graphene added polymeric layer modified graphite electrode and unmodified graphite electrode.
Comparison of Photo‐Esterification Capability of Bismuth Vanadate with Reduced Graphene Oxide Bismuth Vanadate (RGO/BiVO4) Composite for Biodiesel Production from High Free Fatty Acid Containing Non‐Edible Oil
Authors: Ghani Naila , Iqbal Javed , Sadaf Sana , Nawaz Bhatti Haq , Asgher Muhammad
Published: August 2020

Biodiesel has gained much more attention as an alternative and renewable energy source due to the continuous exhaustion of petroleum reserves and their inauspicious environmental effects. Non‐edible feedstocks are economically viable for the production of biodiesel but the presence of higher amount of free fatty acids (FFAs) in these oils is a main hurdle for getting good quality biodiesel. This issue can be addressed through esterification prior to transesterification of oil. This work was designed to evaluate soapnut oil as a source for biodiesel production. Moreover, the catalytic activity of two sunlight active photocatalysts; BiVO4 and RGO/BiVO4 was also compared for the esterification of higher FFA content present in soapnut oil. BiVO4 and RGO/BiVO4 were characterized through SEM, XRD and FT‐IR. Experimental results revealed that RGO/BiVO4 exhibited higher catalytic activity as compare to BiVO4 for the esterification of FFA under sunlight irradiation. Different process variables were optimized and maximum conversion of FFA (88 %) was obtained at 3 : 1 methanol to oil ratio, 5 % catalyst dose, 300 rpm stirring speed and 3 h of reaction time. Esterified oil was then transesterified by using MgO‐KOH heterogeneous catalyst and maximum yield (94 %) of soapnut methyl esters (SNMEs) was obtained at 9 : 1 methanol to oil ratio, 3 % catalyst dose, 2 h reaction time, 80 °C temperature and at 300 rpm stirring speed. The physic‐chemical analysis of synthesized biodiesel revealed that it meets ASTM standards.
Bioelectrochemical Chain Elongation of Short‐Chain Fatty Acids Creates Steering Opportunities for Selective Formation of n‐Butyrate, n‐Valerate or n‐Caproate
Authors: Raes Sanne M. T. , Jourdin Ludovic , Buisman Cees J. N. , Strik David P. B. T. B.
Published: August 2020

Valorization of organic residual streams that produce short‐chain fatty acids (SCFA) require an energetic electron donor to form more valuable elongated products. By microbial electrosynthesis such electrons donor is supplied by an electrode. Here we show that bioelectrochemical chain elongation (BCE) of SCFA was steered to high selective product formation efficiencies depending on the supplied fatty acid. n‐Butyrate, n‐valerate, n‐caproate were in different experimental conditions formed at respectively 94.1, 95.4 and 83.4% carbon‐based selectivity. The reactor microbiomes adapted to the new feeding conditions within a few days. Remarkably, propionate elongation appeared to be preferred over acetate elongation. Propionate elongation resulted in highly selective formation of the odd‐chain fatty acid n‐valerate; this seems contradictory to ethanol chain elongation studies in which acetate is concurrently formed leading to straight fatty acids as by products.
Preparation of Stable CuO/Boron Nitride Nanocomposite Modified Electrode for Selective Electrochemical Detection of L–Cysteine
Authors: Jerome Rajendran , Keerthivasan Pulia Venkatachalapathy , Murugan Nagaraj , Devi Nagarajan Ramila , Sundramoorthy Ashok K.
Published: August 2020

L‐cysteine (Cys) is one of the main amino acid and its deficiency could cause several diseases and biological disorders in our body. Thus, it is important to accurately detect Cys level in biological samples. Herein, we reported a facile strategy to fabricate novel electrode material consisting of conductive hybrid film made of copper oxide‐boron nitride nanosheets (CuO/BN). Powdered X‐ray diffraction (PXRD) and Fourier transform infrared (FT‐IR) spectroscopy results confirmed the successful formation of CuO/BN hybrid nanocomposite. Next, electrochemical and electro‐catalytic properties of CuO/BN hybrid film is studied by cyclic voltammetry and amperometry. Interestingly, CuO/BN coated glassy carbon electrode (GCE) showed excellent electro‐catalytic activity towards Cys oxidation in phosphate buffer solution (0.1 M PBS). Newly developed CuO/BN film modified electrode is exhibited high oxidation peak current at lower potential of +0.45 V compared to bare GCE. CuO/BN/GCE sensor is also utilized for the detection of Cys from 1 to 10 μM and limit of detection (LOD) was found to be 0.58 μM. The selectivity of the sensor is determined by detecting 5 μM Cys in the presence of different interferent molecules. Furthermore, repeatability, reproducibility and stability of the CuO/BN/GCE sensor are also investigated. Finally, CuO/BN/GCE sensor is successfully applied to detect spiked Cys in human blood serum samples with good recovery.
A DFT Study on Transition States of Inhibition of Oxidation by α‐Tocopherol
Authors: Yamabe Shinichi , Tsuchida Noriko , Yamazaki Shoko
Published: August 2020

DFT calculations were performed for reactions of α‐tocopherol (α‐TocH) with peroxy radicals LOO.s, tert‐Bu‐O2., Me‐HC(‐O2.)‐CH=CH‐CH=CHMe, Cl3C‐O2. and F3CCH(Cl)‐O2., so as to examine the anti‐oxidant activity of vitamin E. 2,2,5,7,8‐Pentamethyl‐6‐chromanol (PMCH) was also used as a parent substrate to investigate the effect of the alkyl side chain, phytyl (CH2CH2CH2CH(CH3))3CH3 group, of α‐TocH on the reactivity. The effect of ethanol which is a standard solvent for vitamin E on its reactivity was carefully examined in a system composed of 2,6‐di‐tert‐butyl‐4‐(4′‐methoxyphenyl)‐phenoxyl radical and α‐TocH. All the reaction paths were found to be not with hydrogen‐atom migration but with proton migration. Two types of transition states of LOO. + α‐TocH → LOOH + α‐Toc. were found. One is the concerted proton‐electron transfer for neutral peroxy radicals. The other is the modified single‐electron transfer followed by the Grotthuss‐type proton transfer with intervention of ethanol molecules for electron‐withdrawing peroxy radicals.
Benzoate Ester Functionalized Phenylenediamine Derivatives: Synthesis, Crystal Structure and Optical Properties
Authors: Zhu Guanxing , Zhang Gang
Published: August 2020

Methyl benzoate functionalized phenylenediamine derivatives with the methoxycarbonyl groups at the ortho‐, meta‐ and para‐positions of amino group were synthesized via palladium‐catalyzed Buchwald‐Hartwig reaction and copper‐catalyzed Ullmann amination. Crystallographic analysis unraveled the presences of intra‐ and intermolecular hydrogen bonds in compounds bearing NH groups. Spectroscopic investigation revealed that compounds with amine protected by phenyl showed varied emissions with relatively stronger intensity in solution and in solid state than those of the unprotected ones. All the compounds demonstrated aggregation induced enhanced emissions in THF/water, some of which exhibited tunable emissions according to the water contents. Theoretical calculations unveiled that compound with intramolecular hydrogen bond possessed twisted structure and could undergo one proton transfer process in the excited state, which were essential to its low fluorescence intensity in solution and enhanced emission in the solid state.
A New Approach to Synthesis of Highly Dispersed Gold Nanoparticles via Glucose Oxidase‐Immobilized Hydrogel and Usage in The Reduction of 4‐Nitrophenol
Authors: Ozay Hava , Tarımeri Nur , Gungor Zeynep , Demirbakan Burçak , Özcan Burcu , Sezgintürk Mustafa Kemal , Ozay Ozgur
Published: August 2020

In this study, for the first time in the literature, synthesis of Au(0) nanoparticles supported by a crosslinked gel structure was performed via enzyme‐mediated reduction of Au(III) ions without using any chemical reductant. In our newly‐developed method, glucose oxidase enzymes immobilized in the crosslinked gelatine structure ensured simultaneous reduction of the Au(III) ions diffused within the gel to Au(0). The Au@Gel obtained was structurally characterised with TEM (Transmission electron microscopy), EDX (Energy dispersive X‐ray analysis) elemental mapping, XPS (X‐Ray photoelectron spectroscopy) and XRD (X‐Ray Diffraction) analyses. The catalytic activity of Au(0) particles with nearly 8 nm size in the Au@Gel was investigated for the reduction of 4‐nitrophenol (4‐NP) as a model compound in the presence of NaBH4 as reducing agent. The activation parameters for the reduction reaction of 4‐nitrophenol in the presence of Au@Gel catalyst were determined as Ea= 30.16 kJmol−, ΔH#= 27.52 kJmol− and ΔS#= −197.45 Jmol−K−. The Au@Gel catalyst system, with good catalytic activity, simultaneously has nearly perfect reusability.
Facile Synthesis of Mesoporous Alumina with Tunable Morphology using Template Free Method
Authors: Kanna Narasimharao , Dama Srikanth , Valavarasu G.
Published: August 2020

Mesoporous alumina (MA) with interesting morphologies of flower or three‐dimensional hierarchical spheres like nanostructures were synthesized in the absence of any template. Hydrothermal synthesis strategy was applied for synthesis of mesoporous γ‐ alumina with tunable properties like BET surface area, pore volume, pore size and superior acidic property. Over all experiments were conducted systematically using aluminum sulfate hydrolysis, precipitation, growth/nucleation. The formation of flower like structures of γ‐Al2O3 were characterized by X‐ray powder diffraction (XRD), N2physisorption, scanning electron microscope (SEM), Temperature programmed ammonia desorption (TPD) for acidity, Nuclear magnetic resonance (NMR) spectroscopy. In order to study the effect of chelating agents like urea and role of complexing agents, a series of contrast experiments were carried out. The novel synthesis methodology yielded MAs with exceptionally high surface areas, pore volumes, uniform pore size distributions and versatile acidic strengths. This present investigation provided a simple and effective approach for preparing mesoporous alumina and the different kinds of morphologies structures of alumina can be controlled precisely by choosing appropriate complexing agents and optimum quantity of precipitating agents. This approach of work not only allows us to investigate the growth mechanism of the final product, but also reduces cost and the environmental pollution effectively than other template methods.
Improving LSM‐trie performance by parallel search
Authors: Cheng Wen , Guo Tao , Zeng Lingfang , Wang Yang , Nagel Lars , Süß Tim , Brinkmann André
Published: August 2020

LSM‐trie‐based key‐value (KV) store is often used to manage an ultralarge dataset in reality by introducing a number of sublevels at each level, its linear growth pattern can fairly reduce the write amplification in store operations. Although this design is effective for the write operation, the last level holds a large proportion of KV items, leading to the extreme imbalance of data distribution. Therefore, to support efficient read, we need to carefully consider this imbalance. On the other hand, to ensure that acquired data is latest, the LSM‐trie needs to search the dataset at different levels one by one, and this search method may take a lot of unnecessary time. When the number of items is ultralarge, the random lookup performance may be poor due to the imbalance data distribution. To address this issue, we improve the read performance of the LSM‐trie by changing its serial search to parallel search, using two threads to simultaneously search at the last level and other levels, respectively. Our experiment results show that the read performance of the LSM‐trie can be improved up to 98.35% and on average 71.55%.
Surface Tension and Density of Cr–Mn–Ni Steels with Transformation Induced Plasticity Effect
Authors: Korobeinikov Iurii , Chikhi Nourdine , Fouquart Pascal , Turquais Benjamin , Delacroix Jules , Seetharaman Seshadri , Volkova Olena
Published: August 2020

Thermophysical properties of liquid metal alloys play a crucial role in the variety of processes. Present work reports experimental investigations of two new transformation induced plasticity (TRIP) steels. A classical maximum bubble pressure technique is successfully used to measure surface tension and density of the liquid TRIP‐steel samples in the temperatures range of 1500–1800 °C. Experiments are performed in two different measurement cells from TU Freiberg and Commissariat a l'Energie Atomique (CEA), Cadarache. Capillaries are made of zirconia partially stabilized with yttrium oxide, and the samples are molten in Al2O3 crucibles. Measurements are conducted under the argon atmosphere. Surface tension of the investigated samples rises up to 1700 °C and further remains the same. Density of the new steels obtained in this study is in good agreement with the previously reported values for Fe–Cr alloys with similar Cr content. Density of the alloy is estimated as 875 488–11 885 × T (±218.85 kg m−3) for a 15%Cr alloy and 796 042–06 897 × T (±199 kg m−3) for a 19%Cr alloy.
Lateral response of ultra‐high performance concrete columns confined with high‐strength spiral stirrups
Authors: Chang Wei , Zheng Wenzhong , Hao Meijing
Published: August 2020

The lateral confinement of stirrups can effectively restrain the unstable lateral expansion of confined concrete and improve the load capacity and the ductility of concrete. The lateral response of stirrups affects the effective confinements on confined concrete and the dilation of core concrete. However, the lateral response of confined concrete has not received enough attention. In this paper, the lateral responses of 24 ultra‐high performance concrete (UHPC) and ultra‐high fiber‐reinforced performance concrete (UHPFRC) columns confined with high strength stirrups were obtained by experiments. The investigated parameters included concrete strength, stirrups volumetric ratio, and steel fibers contents. The axial stress‐lateral strain curves and lateral strain‐axial strain responses of specimens were presented to understand the dilation of concrete. The results showed that high strength concrete and high steel fibers contents decreased the dilation of concrete, when stirrups volumetric ratio increased from 1.0 to 2.0%, the dilation of concrete increased by 1.45~2.09 times. Furthermore, the lateral strain‐axial strain response prediction models were developed by introducing the effects of steel fibers, which were suitable for predicting the lateral strain‐axial strain of confined concrete.
Influence of axial tension on the shear strength of RC beams without stirrups
Authors: Pham Duc Toan , Fouré Bernard , Pinoteau Nicolas , Abouri Salim , Mège Romain
Published: August 2020

This contribution is addressing the investigation on the effect of axial tension on the shear strength of reinforced concrete beam elements without stirrups. The paper presents the results of a test program of 15 beams without stirrups that differed from each other mainly by the intensity of the axial tensile force N. During the tests, cracking was measured by Digital Image Correlation technique to identify the crack evolution mechanisms. After some consideration on the resisting mechanisms, the experimental results are compared with several code formulas to predict the shear strength VRc. Then an empirical formula is proposed for the variation of VRc between its two limits: the values for N = 0 and for VRc = 0 at the ultimate limit state of axial tension. This formula makes it possible to easily design for shear and tension.