bluuebunny/crossref_metadata_2025 huggingface dataset:
Alternative Aqueous Phase Synthesis of a PtRu/C Electrocatalyst for Direct Methanol Fuel Cells
Authors: Wang Qijun , Zhou Ya-Wei , Jin Zhao , Chen Chunguang , Li Hong , Cai Wen-Bin
Published: July 2021

Carbon-supported PtRu nanoalloy (PtRu/C) is widely used as the anode catalyst for direct methanol fuel cells (DMFC), and an aqueous phase synthesis of PtRu/C is in high demand due to for energy-saving and environmentally-benign considerations, however, it is very challenging to attain stoichiometric reduction, good dispersion and a high alloying degree. Herein, we report a facile aqueous phase approach with dimethylamine borane (DMAB) as the reducing agent to synthesize a PtRu/C(DMAB). TEM, XRD, XPS and ICP-AES characterizations indicate that the structural parameters in the PtRu/C(DMAB) are improved significantly as compared to those obtained in a PtRu/C(NaBH4) and a commercial PtRu/C, contributing to an enhanced electrocatalytic performance. It turns out that the PtRu/C(DMAB) exhibits the highest methanol electro-oxidation (MOR) performance among all of the tested samples, with the peak current up to 1.8 times as much as that of the state-of-the-art commercial PtRu/C, corroborating the highest output power density in comparative DMFC tests. In-situ attenuated total reflection infrared (ATR-IR) spectroscopy correlates the higher methanol electro-oxidation performance of the PtRu/C(DMAB) with its enhanced CO resistance and CO2 generation. This simple aqueous synthetic approach may provide an alternative route for developing efficient anode electrocatalysts of DMFCs.
The Amino Acids Motif -32GSSYN36- in the Catalytic Domain of E. coli Flavorubredoxin NO Reductase Is Essential for Its Activity
Authors: Martins Maria C. , Fernandes Susana F. , Salgueiro Bruno A. , Soares Jéssica C. , Romão Célia V. , Soares Cláudio M. , Lousa Diana , Folgosa Filipe , Teixeira Miguel
Published: July 2021

Flavodiiron proteins (FDPs) are a family of modular and soluble enzymes endowed with nitric oxide and/or oxygen reductase activities, producing N2O or H2O, respectively. The FDP from Escherichia coli, which, apart from the two core domains, possesses a rubredoxin-like domain at the C-terminus (therefore named flavorubredoxin (FlRd)), is a bona fide NO reductase, exhibiting O2 reducing activity that is approximately ten times lower than that for NO. Among the flavorubredoxins, there is a strictly conserved amino acids motif, -G[S,T]SYN-, close to the catalytic diiron center. To assess its role in FlRd’s activity, we designed several site-directed mutants, replacing the conserved residues with hydrophobic or anionic ones. The mutants, which maintained the general characteristics of the wild type enzyme, including cofactor content and integrity of the diiron center, revealed a decrease of their oxygen reductase activity, while the NO reductase activity—specifically, its physiological function—was almost completely abolished in some of the mutants. Molecular modeling of the mutant proteins pointed to subtle changes in the predicted structures that resulted in the reduction of the hydration of the regions around the conserved residues, as well as in the elimination of hydrogen bonds, which may affect proton transfer and/or product release.
Photocatalytic Degradation of Thiacloprid Using Tri-Doped TiO2 Photocatalysts: A Preliminary Comparative Study
Authors: Mancuso Antonietta , Navarra Wanda , Sacco Olga , Pragliola Stefania , Vaiano Vincenzo , Venditto Vincenzo
Published: July 2021

Different tri-doped TiO2 photocatalysts (Fe-N-P/TiO2, Fe-N-S/TiO2, Fe-Pr-N/TiO2, Pr-N-S/TiO2, and P-N-S/TiO2) were successfully prepared and tested in the photocatalytic removal of thiacloprid (THI) under UV-A, visible, and direct solar light irradiation. The physical-chemical properties of the prepared catalysts were analyzed by different characterization techniques, revealing that dopants are effectively incorporated into the anatase TiO2 lattice, resulting in a decrease of the energy band gap. The reduction of photoluminescence intensity indicates a lower combination rate and longer lifespan of photogenerated carriers of all doped samples in comparison with the un-doped TiO2. The doped photocatalysts not only significantly promote the photodegradation under UV-A light irradiation but also extend the optical response of TiO2 to visible light region, and consequently improve the visible light degradation of THI. Fe-N-P tri-doped TiO2 sample exhibits the highest THI photodegradation degree (64% under UV-A light, 29% under visible light and 73% under solar light).
Cascading Old Yellow Enzyme, Alcohol Dehydrogenase and Glucose Dehydrogenase for Selective Reduction of (E/Z)-Citral to (S)-Citronellol
Authors: Jia Yunpeng , Wang Qizhou , Qiao Jingjing , Feng Binbin , Zhou Xueting , Jin Lijun , Feng Yingting , Yang Duxia , Lu Chenze , Ying Xiangxian
Published: July 2021

Citronellol is a kind of unsaturated alcohol with rose-like smell and its (S)-enantiomer serves as an important intermediate for organic synthesis of (-)-cis-rose oxide. Chemical methods are commonly used for the synthesis of citronellol and its (S)-enantiomer, which suffers from severe reaction conditions and poor selectivity. Here, the first one-pot double reduction of (E/Z)-citral to (S)-citronellol was achieved in a multi-enzymatic cascade system: N-ethylmaleimide reductase from Providencia stuartii (NemR-PS) was selected to catalyze the selective reduction of (E/Z)-citral to (S)-citronellal, alcohol dehydrogenase from Yokenella sp. WZY002 (YsADH) performed the further reduction of (S)-citronellal to (S)-citronellol, meanwhile a variant of glucose dehydrogenase from Bacillus megaterium (BmGDHM6), together with glucose, drove efficient NADPH regeneration. The Escherichia coli strain co-expressing NemR-PS, YsADH, and BmGDHM6 was successfully constructed and used as the whole-cell catalyst. Various factors were investigated for achieving high conversion and reducing the accumulation of the intermediate (S)-citronellal and by-products. 0.4 mM NADP+ was essential for maintaining high catalytic activity, while the feeding of the cells expressing BmGDHM6 effectively eliminated the intermediate and by-products and shortened the reaction time. Under optimized conditions, the bio-transformation of 400 mM citral caused nearly complete conversion (>99.5%) to enantio-pure (S)-citronellol within 36 h, demonstrating promise for industrial application.
Chemo-Enzymatic Cascade for the Generation of Fragrance Aldehydes
Authors: Schwendenwein Daniel , Ressmann Anna K. , Entner Marcello , Savic Viktor , Winkler Margit , Rudroff Florian
Published: July 2021

In this study, we present the synthesis of chiral fragrance aldehydes, which was tackled by a combination of chemo-catalysis and a multi-enzymatic in vivo cascade reaction and the development of a highly versatile high-throughput assay for the enzymatic reduction of carboxylic acids. We investigated a biocompatible metal-catalyzed synthesis for the preparation of α or β substituted cinnamic acid derivatives which were fed directly into the biocatalytic system. Subsequently, the target molecules were synthesized by an enzymatic cascade consisting of a carboxylate reduction, followed by the selective C-C double bond reduction catalyzed by appropriate enoate reductases. We investigated a biocompatible oxidative Heck protocol and combined it with cells expressing a carboxylic acid reductase from Neurospora crassa (NcCAR) and an ene reductase from Saccharomyces pastorianus for the production fragrance aldehydes.
ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline
Authors: Cheng Yong , Wang Xiuxiu , Mei Yu , Wang Dan , Ji Changchun
Published: July 2021

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ⋅O2 radical was the active species in the reaction.
Tight Interplay between Replication Stress and Competence Induction in Streptococcus pneumoniae
Authors: Khemici Vanessa , Prudhomme Marc , Polard Patrice
Published: July 2021

Cells respond to genome damage by inducing restorative programs, typified by the SOS response of Escherichia coli. Streptococcus pneumoniae (the pneumococcus), with no equivalent to the SOS system, induces the genetic program of competence in response to many types of stress, including genotoxic drugs. The pneumococcal competence regulon is controlled by the origin-proximal, auto-inducible comCDE operon. It was previously proposed that replication stress induces competence through continued initiation of replication in cells with arrested forks, thereby increasing the relative comCDE gene dosage and expression and accelerating the onset of competence. We have further investigated competence induction by genome stress. We find that absence of RecA recombinase stimulates competence induction, in contrast to SOS response, and that double-strand break repair (RexB) and gap repair (RecO, RecR) initiation effectors confer a similar effect, implying that recombinational repair removes competence induction signals. Failure of replication forks provoked by titrating PolC polymerase with the base analogue HPUra, over-supplying DnaA initiator, or under-supplying DnaE polymerase or DnaC helicase stimulated competence induction. This induction was not correlated with concurrent changes in origin-proximal gene dosage. Our results point to arrested and unrepaired replication forks, rather than increased comCDE dosage, as a basic trigger of pneumococcal competence.
Circular RNA as An Epigenetic Regulator in Chronic Liver Diseases
Authors: Zeng Xianhui , Yuan Xianglei , Cai Qiuyu , Tang Chengwei , Gao Jinhang
Published: July 2021

Circular RNA (circRNA) is a type of non-coding RNA characterized by a covalently closed continuous loop. CircRNA is generated by pre-mRNA through back-splicing and is probably cleared up by extracellular vesicles. CircRNAs play a pivotal role in the epigenetic regulation of gene expression at transcriptional and post-transcriptional levels. Recently, circRNAs have been demonstrated to be involved in the regulation of liver homeostasis and diseases. However, the epigenetic role and underlying mechanisms of circRNAs in chronic liver diseases remain unclear. This review discussed the role of circRNAs in non-neoplastic chronic liver diseases, including alcoholic liver disease (ALD), metabolic-associated fatty liver disease (MAFLD), viral hepatitis, liver injury and regeneration, liver cirrhosis, and autoimmune liver disease. The review also highlighted that further efforts are urgently needed to develop circRNAs as novel diagnostics and therapeutics for chronic liver diseases.
What the EdTech Experience in Refugee Camps Can Teach Us in Times of School Closure. Blended Learning, Modular and Mobile Programs Are Key to Keeping Disadvantaged Learners in Education
Authors: Tobin Eilis , Hieker Carola
Published: July 2021

COVID-19 is reshaping education. UNESCO estimates that at the peak in April 2020 COVID-19 disrupted the education of 1.5 billion enrolled learners in schools and universities in 190 countries. This period of unparalleled educational interruption has prompted a rapid reaction, a move to explore online distance learning solutions. Simultaneously, it has exposed the challenges and complexity of distance learning utilising Educational Technology (EdTech). Despite the many technological innovations, these challenges are not new to refugee learners, their educators and remote learning technology providers. In this article, the authors sought to explore frontline practitioners’ ‘lived experience’ of providing education utilising EdTech when education is disrupted by forced displacement. A small scale, explorative, qualitative study was conducted with educators in refugee camps and urban settings, in Greece, Jordan, Kenya and Rwanda, prior to the pandemic. Expert interviews revealed that EdTech programmes cannot be a stand-alone solution. Blended learning programmes that are context-specific, modular, optimised for mobile technology and delivered by trained and supported teachers are the most effective. The article ends with a reflection on how these findings can be applied globally when learning is disrupted by whatever means and lead to an equitable and sustainable recovery for all.
Parental Stress and Scalp Hair Cortisol in Excessively Crying Infants: A Case Control Study
Authors: de Kruijff Ineke , Tromp Ellen , Lambregtse-van den Berg Mijke P. , Vlieger Arine M. , Benninga Marc A. , de Rijke Yolanda B. , van den Akker Erica LT.
Published: July 2021

Background: Caring for an excessively crying infant (ECI) can be stressful for mothers and fathers and is associated with mental and bonding problems. Hair cortisol offers a unique measure for the biological reaction of the body to stress over time. Methods: In this case-control study, scalp hair cortisol concentrations (HCC) were measured using liquid chromatography-tandem mass spectrometry (LC-MS) in 35 mothers and 23 fathers and their ECIs. The control group consisted of 64 mothers and 63 fathers of non-ECIs of similar age. Parental stress, depression, anxiety and bonding were assessed using validated questionnaires. Results: Mean HCC were significantly lower in mothers and fathers of ECIs (2.3 pg/mg, 95% CI 1.8–2.9 and 1.6 pg/mg, 95% CI 1.3–2.0) than that in control mothers and fathers (3.2 pg/mg, 95% CI 3.0–3.7 and 2.9 pg/mg, 95% CI 2.5–3.5). In the total group of parents and within the parents of ECIs, HCC were not associated with negative feelings. In the control group, HCC showed a positive association with stress and depression (r = 0.207, p = 0.020 and r = 0.221, p = 0.013). In infants, no differences were found in mean HCC between the ECI group and the control group. No associations were found between maternal and infant HCC, paternal and infant HCC and maternal and paternal HCC. Conclusion: Parents of ECIs showed significantly lower HCC than control parents, reflecting a diminished response of the hypothalamic-pituitary-adrenal (HPA) axis. More research is needed to examine whether this decrease in response is pre-existing or caused by excessive infant crying.
Effect of Bias Voltage on Microstructure and Properties of Tantalum Nitride Coatings Deposited by RF Magnetron Sputtering
Authors: Dai Wei , Shi Yunzhan
Published: July 2021

TaNx coatings were deposited by RF magnetron sputtering with different bias voltages. The growth morphology, crystalline structure, chemical bond structure, hardness and elastic modulus, adhesion strength and tribological performance of the coatings were studied as a function of the bias voltage. The results showed that an increasing bias voltage refines the coating grains and facilitates structure densification. Simultaneously, the structure of the TaNx coatings transfers from a composite structure consisting of TaN and Ta2N crystals, through a single composite mainly composed of the Ta2N crystal, to an amorphous structure as the bias voltage increases from low to high, indicating that the phase composition of the TaNx coatings can be varied by the bias voltage. The coating composed of Ta2N crystal showed a good overall performance including enhanced hardness, enhanced adhesive strength, and good tribological performance with enhanced wear resistance and a low friction coefficient of 0.18.
A Past, Present, and Prospective Review on Microwave Nondestructive Evaluation of Composite Coatings
Authors: Siang Teng Wei , Firdaus Akbar Muhammad , Nihad Jawad Ghassan , Yee Tan Shin , Mohd Sazali Mohd Ilyas Sobirin
Published: July 2021

Recent years have witnessed an increase in the use of composite coatings for numerous applications, including aerospace, aircraft, and maritime vessels. These materials owe this popularity surge to the superior strength, weight, stiffness, and electrical insulation they exhibit over conventional substances, such as metals. The growing demand for such materials is accompanied by the inevitable need for fast, accurate, and affordable nondestructive testing techniques to reveal any possible defects within the coatings or any defects under coating. However, typical nondestructive testing (NDT) techniques such as ultrasonic testing (UT), infrared thermography (IRT), eddy current testing (ECT), and laser shearography (LS) have failed to provide successful results when inspecting composite coatings. Consequently, microwave NDT techniques have emerged to compensate for the shortcomings of traditional NDT approaches. Numerous microwave NDT methods have been reported for composite coatings inspection. Although existing microwave NDT methods have shown successful inspection of composite coatings, they often face several challenges, such as low spatial image quality and extensive data interpretation. Nevertheless, many of these limitations can be addressed by utilizing microwave NDT techniques with modern technologies such as soft computing. Artificially intelligent techniques have greatly enhanced the reliability and accuracy of microwave NDT techniques. This paper reviews various traditional NDT techniques and their limitations in inspecting composite coatings. In addition, the article includes a detailed review of several microwave NDT techniques and their benefits in evaluating composite coatings. The paper also highlights the advantages of using the recently reported microwave NDT approaches employing artificial intelligence approaches. This review demonstrates that microwave NDT techniques in conjunction with artificial intelligence approaches have excellent prospects for further enhancing composite coatings inspection and assessment efficiency. The review aimed to provide the reader with a comprehensive overview of most NDT techniques used for composite materials alongside their most salient features.
Antibacterial and Freshness-Preserving Mechanisms of Chitosan-Nano-TiO2-Nano-Ag Composite Materials
Authors: Dong Zihao , Li Ran , Gong Yan
Published: July 2021

With chitosan, nano-TiO2 and nano-Ag as raw materials, nano-TiO2 and nano-TiO2-Ag were modified by a surface modifier-sodium laurate. Chitosan (CTS), chitosan-nano-TiO2 (CTS-TiO2), and chitosan-nano-TiO2-nano-Ag (CTS-TiO2-Ag) composite materials and corresponding films were prepared by a solution co-blending method. Then, the antibacterial performances of the above three types of materials against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis were compared. Moreover, potato and strawberry weight loss rates, peroxidase activity, and vitamin C contents after different film coating treatments were measured. Compared with CTS films, the CTS-TiO2-Ag and CTS-TiO2 composite films both showed better physical properties, and both demonstrated higher antibacterial effects, especially for E. coli. Measurement of physiological indices in fruits and vegetables showed that the freshness-preserving effect of CTS-TiO2-Ag coating films was the most significant. In all, the CTS-TiO2-Ag coating films can actively contribute to the storage of fruits and vegetables at room temperature, and better ensure product quality. Thus, such films are meaningful for research and development of new fruit freshness-keeping techniques and materials.
A Multistate Adsorption Model for the Adsorption of C14EO4 and C14EO8 at the Solution/Air Interface
Authors: Fainerman Valentin B. , Kovalchuk Volodymyr I. , Aksenenko Eugene V. , Ravera Francesca , Liggieri Libero , Loglio Giuseppe , Makievski Alexander V. , Mishchuk Natalia O. , Schneck Emanuel , Miller Reinhard
Published: July 2021

The dynamic and equilibrium properties of adsorption layers of poly (oxyethylene) alkyl ether (CnEOm) can be well described by the reorientation model. In its classical version, it assumes two adsorption states; however, there are obviously surfactants that can adsorb in more than two possible conformations. The experimental data for C14EO4 and C14EO8 (dynamic and equilibrium surface tensions and surface dilational visco-elasticity as measured by bubble profile analysis tensiometry) are used to verify if a reorientation model with more than two possible adsorption states can better describe the complete set data of CnEOm adsorption layers at the water/air interface. The proposed refined theoretical model allows s different states of the adsorbing molecules at the interface. The comparison between the model and experiment demonstrates that, for C14EO4, the assumption of s = 5 adsorption states provides a much better agreement than for s = 2, while for C14EO8, a number of s = 10 adsorption states allows an optimum data description.
Response of Viscoelastic Turbulent Pipeflow Past Square Bar Roughness: The Effect on Mean Flow
Authors: Goswami Shubham , Hemmati Arman
Published: July 2021

The influence of viscoelastic polymer additives on response and recovery of turbulent pipeflow over square bar roughness elements was examined using Direct Numerical Simulations at a Reynolds number of 5×103. Two different bar heights for the square bar roughness elements were examined, h/D=0.05 and 0.1. A Finitely Extensible Non-linear Elastic-Peterlin (FENE-P) rheological model was employed for modeling viscoelastic fluid features. The rheological parameters for the simulation corresponded to a high concentration polymer of 160 ppm. Recirculation regions formed behind the bar elements by the viscoelastic fluid were shorter than those associated with Newtonian fluid, which was attributed to mixed effects of viscous and elastic forces due to the added polymers. The recovery of the mean viscoelastic flow was faster. The pressure losses on the surface of the roughness were larger compared to the Newtonian fluid, and the overall contribution to local drag was reduced due to viscoelastic effects.
Synthesis and Structures of TiIII and TiIV Complexes Supported by a Bulky Guanidinate Ligand
Authors: Noor Awal
Published: July 2021

In this work, titanium complexes of the bidentate bulky guanidine ligand [{(Dip)N}2CNR2]H (where Dip = C6H3iPr2-2,6 and R = CH(CH3)2) (LH) were prepared. Reaction of LH with one equivalent of [(CH3)2NTiCl3] underwent amine elimination to afford the monomeric complex [LTiCl3] (1) in high yield. Attempts to reduce 1 with potassium graphite (KC8) in tetrahydrofuran (THF) were unsuccessful. However, reacting 1 with 3.3 equivalents of KC8 in hexane led to the first example of structurally characterized mono-guanidinate ligand stabilized dimeric TiIII complex [LTiCl(μ–Cl)]2 (2). The synthesized complexes were characterized by NMR spectroscopy and the structures were further confirmed by X-ray crystallography.
Reinforcement of Recycled Aggregate by Microbial-Induced Mineralization and Deposition of Calcium Carbonate—Influencing Factors, Mechanism and Effect of Reinforcement
Authors: Feng Chunhua , Cui Buwen , Ge Haidong , Huang Yihong , Zhang Wenyan , Zhu Jianping
Published: July 2021

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.
Mitigating Corrosion Effects of Ti-48Al-2Cr-2Nb Alloy Fabricated via Electron Beam Melting (EBM) Technique by Regulating the Immersion Conditions
Authors: Abdo Hany S. , Abdus Samad Ubair , Mohammed Jabair Ali , Ragab Sameh A. , Seikh Asiful H.
Published: July 2021

The corrosion behavior of newly fabricated γ-TiAl alloy was studied using electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization (CPP) techniques. The γ-TiAl alloy was produced from powder with compositions of Ti-48Al-2Cr-2Nb processed using electron beam melting (EBM) technique. The corrosion behavior of the bulk alloy was investigated in 1 M HCl solution for different immersion times and temperatures. The experimental results suggest that the fabricated alloy exhibits good resistance to corrosion in acid solution at room temperature. The results also indicate that with an increase in immersion time and solution temperature, the corrosion potential (Ecorr) shifts to a higher positive value, resulting in an increase in corrosion current (jcorr) and consequently a decrease in the corrosion resistance (Rp) of the alloy.
Relationship between Provider Communication Behaviors and the Quality of Life for Patients with Advanced Cancer in Saudi Arabia
Authors: Alhofaian Aisha , Zhang Amy , Gary Faye A.
Published: July 2021

Context: Patients with advanced cancer from Saudi Arabia are often not well informed about diagnoses, prognoses, and treatment options. Poor communication can lead to health-care decisions that insufficiently meet patients’ preferences, concerns, and needs and that subsequently affect patients’ quality of life. Objectives: The purpose of this study is to examine the relationship between provider communication behaviors and the quality of life of patients with advanced cancer. Method: A cross-sectional, correlation design was used in the present study, in which 159 patients with confirmed diagnoses of stage III or IV solid cancer were surveyed. Results: The mean summary score of the patients’ quality of life was 57.31. We found a significant relationship between provider communication behaviors and patient quality of life (β = 0.18, b = 0.35, SE = 0.15, p = 0.021). In addition, R2 shows that only 3.4% of variance in patient quality of life is predicated on provider communication behaviors. Conclusions: The relationship between provider communication behaviors and patient quality of life was low (r = 0.18). A possible reason for this is that provider communication behaviors are not the only factor that affects patient quality of life; other variables, such as the patient’s age, cancer type, and level of awareness, can also have an effect. Another possible explanation is that communication behaviors between patients and providers may vary depending on the level of cultural contact.
Correction: Rijnsdorp et al. Impact of the Noise Penalty Factor on Quantification in Bayesian Penalized Likelihood (Q.Clear) Reconstructions of 68Ga-PSMA PET/CT Scans. Diagnostics 2021, 11, 847
Authors: Rijnsdorp Sjoerd , Roef Mark J. , Arends Albert J.
Published: July 2021

In the original article [...]
Is Neuropathic Pain a Good Marker of Peripheral Neuropathy in Hospice Patients with Advanced Cancer? The Single Center Pilot Study
Authors: Drat-Gzubicka Joanna , Pyszora Anna , Budzyński Jacek , Currow David , Krajnik Małgorzata
Published: July 2021

Neuropathic pain (NP) affects approximately 30% of patients with advanced cancer. The prevalence of neuropathic pain related to peripheral neuropathy (NP-RPN) in these patients is not known. The aim of the study was to evaluate NP-RPN prevalence in hospice patients and to find out whether the absence of this pain is sufficient to rule out peripheral neuropathy. The study included a total of 76 patients with advanced cancer who were cared for at inpatient hospices. All patients were asked about shooting or burning pain (of the feet and hands), were examined systematically for sensory deficits and had a nerve conduction study performed. NP-RPN was found in 29% of the patients. Electrophysiologically-diagnosed peripheral neuropathy was found in 79% of patients, and the diagnostic electrophysiological criteria for neuropathy were met by one half of the patients without NP-RPN. The severity of NP-RPN was correlated with the clinically assessed severity of sensory neuropathy and the Karnofsky score, but was not correlated with the intensity of the clinical signs of motor neuropathy. The presence of NP-RPN did not reflect greater prevalence of motor and sensory abnormalities in neurological and electrophysiological examinations. The absence of NP-RPN did not rule out polyneuropathy in hospice patients.
46,XX DSD: Developmental, Clinical and Genetic Aspects
Authors: Alkhzouz Camelia , Bucerzan Simona , Miclaus Maria , Mirea Andreea-Manuela , Miclea Diana
Published: July 2021

Differences in sex development (DSD) in patients with 46,XX karyotype occur by foetal or postnatal exposure to an increased amount of androgens. These disorders are usually diagnosed at birth, in newborns with abnormal genitalia, or later, due to postnatal virilization, usually at puberty. Proper diagnosis and therapy are mostly based on the knowledge of normal development and molecular etiopathogenesis of the gonadal and adrenal structures. This review aims to describe the most relevant data that are correlated with the normal and abnormal development of adrenal and gonadal structures in direct correlation with their utility in clinical practice, mainly in patients with 46,XX karyotype. We described the prenatal development of structures together with the main molecules and pathways that are involved in sex development. The second part of the review described the physical, imaging, hormonal and genetic evaluation in a patient with a disorder of sex development, insisting more on patients with 46,XX karyotype. Further, 95% of the etiology in 46,XX patients with disorders of sex development is due to congenital adrenal hyperplasia, by enzyme deficiencies that are involved in the hormonal synthesis pathway. The other cases are explained by genetic abnormalities that are involved in the development of the genital system. The phenotypic variability is very important in 46,XX disorders of sex development and the knowledge of each sign, even the most discreet, which could reveal such disorders, mainly in the neonatal period, could influence the evolution, prognosis and life quality long term.
Exploration and Exploitation Zones in a Minimalist Swarm Optimiser
Authors: al-Rifaie Mohammad Majid
Published: July 2021

The trade off between exploration and exploitation is one of the key challenges in evolutionary and swarm optimisers which are led by guided and stochastic search. This work investigates the exploration and exploitation balance in a minimalist swarm optimiser in order to offer insights into the population’s behaviour. The minimalist and vector-stripped nature of the algorithm—dispersive flies optimisation or DFO—reduces the challenges of understanding particles’ oscillation around constantly changing centres, their influence on one another, and their trajectory. The aim is to examine the population’s dimensional behaviour in each iteration and each defined exploration-exploitation zone, and to subsequently offer improvements to the working of the optimiser. The derived variants, titled unified DFO or uDFO, are successfully applied to an extensive set of test functions, as well as high-dimensional tomographic reconstruction, which is an important inverse problem in medical and industrial imaging.
Viscosity and Rheological Properties of Graphene Nanopowders Nanofluids
Authors: Bakak Abderrahim , Lotfi Mohamed , Heyd Rodolphe , Ammar Amine , Koumina Abdelaziz
Published: July 2021

The dynamic viscosity and rheological properties of two different non-aqueous graphene nano-plates-based nanofluids are experimentally investigated in this paper, focusing on the effects of solid volume fraction and shear rate. For each nanofluid, four solid volume fractions have been considered ranging from 0.1% to 1%. The rheological characterization of the suspensions was performed at 20 ∘C, with shear rates ranging from 10−1s−1 to 103s−1, using a cone-plate rheometer. The Carreau–Yasuda model has been successfully applied to fit most of the rheological measurements. Although it is very common to observe an increase of the viscosity with the solid volume fraction, we still found here that the addition of nanoparticles produces lubrication effects in some cases. Such a result could be very helpful in the domain of heat extraction applications. The dependence of dynamic viscosity with graphene volume fraction was analyzed using the model of Vallejo et al.
News Video Summarization Combining SURF and Color Histogram Features
Authors: Liang Buyun , Li Na , He Zheng , Wang Zhongyuan , Fu Youming , Lu Tao
Published: July 2021

Because the data volume of news videos is increasing exponentially, a way to quickly browse a sketch of the video is important in various applications, such as news media, archives and publicity. This paper proposes a news video summarization method based on SURF features and an improved clustering algorithm, to overcome the defects in existing algorithms that fail to account for changes in shot complexity. Firstly, we extracted SURF features from the video sequences and matched the features between adjacent frames, and then detected the abrupt and gradual boundaries of the shot by calculating similarity scores between adjacent frames with the help of double thresholds. Secondly, we used an improved clustering algorithm to cluster the color histogram of the video frames within the shot, which merged the smaller clusters and then selected the frame closest to the cluster center as the key frame. The experimental results on both the public and self-built datasets show the superiority of our method over the alternatives in terms of accuracy and speed. Additionally, the extracted key frames demonstrate low redundancy and can credibly represent a sketch of news videos.
Source Symbol Purging-Based Distributed Conditional Arithmetic Coding
Authors: Li Jingjian , Wang Wei , Mo Hong , Zhao Mengting , Chen Jianhua
Published: July 2021

A distributed arithmetic coding algorithm based on source symbol purging and using the context model is proposed to solve the asymmetric Slepian–Wolf problem. The proposed scheme is to make better use of both the correlation between adjacent symbols in the source sequence and the correlation between the corresponding symbols of the source and the side information sequences to improve the coding performance of the source. Since the encoder purges a part of symbols from the source sequence, a shorter codeword length can be obtained. Those purged symbols are still used as the context of the subsequent symbols to be encoded. An improved calculation method for the posterior probability is also proposed based on the purging feature, such that the decoder can utilize the correlation within the source sequence to improve the decoding performance. In addition, this scheme achieves better error performance at the decoder by adding a forbidden symbol in the encoding process. The simulation results show that the encoding complexity and the minimum code rate required for lossless decoding are lower than that of the traditional distributed arithmetic coding. When the internal correlation strength of the source is strong, compared with other DSC schemes, the proposed scheme exhibits a better decoding performance under the same code rate.
EEG-Based Emotion Recognition by Exploiting Fused Network Entropy Measures of Complex Networks across Subjects
Authors: Yao Longxin , Wang Mingjiang , Lu Yun , Li Heng , Zhang Xue
Published: July 2021

It is well known that there may be significant individual differences in physiological signal patterns for emotional responses. Emotion recognition based on electroencephalogram (EEG) signals is still a challenging task in the context of developing an individual-independent recognition method. In our paper, from the perspective of spatial topology and temporal information of brain emotional patterns in an EEG, we exploit complex networks to characterize EEG signals to effectively extract EEG information for emotion recognition. First, we exploit visibility graphs to construct complex networks from EEG signals. Then, two kinds of network entropy measures (nodal degree entropy and clustering coefficient entropy) are calculated. By applying the AUC method, the effective features are input into the SVM classifier to perform emotion recognition across subjects. The experiment results showed that, for the EEG signals of 62 channels, the features of 18 channels selected by AUC were significant (p < 0.005). For the classification of positive and negative emotions, the average recognition rate was 87.26%; for the classification of positive, negative, and neutral emotions, the average recognition rate was 68.44%. Our method improves mean accuracy by an average of 2.28% compared with other existing methods. Our results fully demonstrate that a more accurate recognition of emotional EEG signals can be achieved relative to the available relevant studies, indicating that our method can provide more generalizability in practical use.
Granger-Causality Inference of the Existence of Unobserved Important Components in Network Analysis
Authors: Elsegai Heba
Published: July 2021

Detecting causal interrelationships in multivariate systems, in terms of the Granger-causality concept, is of major interest for applications in many fields. Analyzing all the relevant components of a system is almost impossible, which contrasts with the concept of Granger causality. Not observing some components might, in turn, lead to misleading results, particularly if the missing components are the most influential and important in the system under investigation. In networks, the importance of a node depends on the number of nodes connected to this node. The degree of centrality is the most commonly used measure to identify important nodes in networks. There are two kinds of degree centrality, which are in-degree and out-degree. This manuscrpt is concerned with finding the highest out-degree among nodes to identify the most influential nodes. Inferring the existence of unobserved important components is critical in many multivariate interacting systems. The implications of such a situation are discussed in the Granger-causality framework. To this end, two of the most recent Granger-causality techniques, renormalized partial directed coherence and directed partial correlation, were employed. They were then compared in terms of their performance according to the extent to which they can infer the existence of unobserved important components. Sub-network analysis was conducted to aid these two techniques in inferring the existence of unobserved important components, which is evidenced in the results. By comparing the results of the two conducted techniques, it can be asserted that renormalized partial coherence outperforms directed partial correlation in the inference of existing unobserved important components that have not been included in the analysis. This measure of Granger causality and sub-network analysis emphasizes their ubiquitous successful applicability in such cases of the existence of hidden unobserved important components.
A Sustainable Energy Distribution Configuration for Microgrids Integrated to the National Grid Using Back-to-Back Converters in a Renewable Power System
Authors: Alayi Reza , Zishan Farhad , Mohkam Mahdi , Hoseinzadeh Siamak , Memon Saim , Garcia Davide Astiaso
Published: July 2021

A desire to produce power in microgrids has grown as the demand for electricity has expanded and the cost of installing modern transmission lines over long distances has become infeasible. As such, microgrids pose DC/AC harmonic distortion losses to the voltage supply that eventually fluctuate the output voltage. The key takeaways that this study presents are: (a) a configuration for microgrids integrated to the national grid using back-to-back converters in a renewable power system is achieved; (b) different scenarios of various schemes of sustainability of the power management in microgrids are analyzed; and (c) the reliable and stable network output power distribution is achieved. In this, the proposed control configuration provides space for construction and stability of the power system with sustainability of the power management. The results show that this current configuration works and stabilizes the network in the shortest time possible, and that the DC connection voltage is regulated and maintains reliable network output despite declining slope controllers, DC power and voltage, and power electronic back-to-back converters. Overall, the simulation results show that the proposed system shows acceptable performance under different scenarios. The accuracy of the results is validated with mathematical formulation simulation using MATLAB software. This system can be utilized in distant regions where there is no power grid or in areas where, despite having a power infrastructure, renewable energies are used to supply the output load for the majority of the day and night.
An Improved Droop Control Strategy for Grid-Connected Inverter Applied in Grid Voltage Inter-Harmonics and Fundamental Frequency Fluctuation
Authors: Xu Wanwan , Wang Bin , Liu Jiang , Li Da
Published: July 2021

This paper presents a current suppression method based on a droop control strategy under distorted grid voltage with inter-harmonics and fundamental frequency fluctuation. In this proposed strategy, the current incomplete derivation controller is employed to decrease the negative impact caused by harmonic and inter-harmonic grid voltage. This method provides a good dynamic response and has low complexity against the inter-harmonics with unfixed fundamental frequency. Based on a mathematical model of the grid-connected inverter, we designed novel instantaneous frequency detection and feed-forward methods to suppress the grid fundamental frequency fluctuation impacts. Then the main parameters were analyzed. The simulation and experimental results verified the feasibility and effectiveness of the proposed method.
Gate All around with Back Gate NAND Flash Structure for Excellent Reliability Characteristics in Program Operation
Authors: Sim Jae-Min , Kim Bong-Seok , Nam In-Ho , Song Yun-Heub
Published: July 2021

A gate all around with back-gate (GAAB) structure was proposed for 3D NAND Flash memory technology. We demonstrated the excellent characteristics of the GAAB NAND structure, especially in the self-boosting operation. Channel potential of GAAB shows a gradual slope compared with a conventional GAA NAND structure, which leads to excellent reliability characteristics in program disturbance, pass disturbance and oxide break down issue. As a result, the GAAB structure is expected to be appropriate for a high stacking structure of future memory structure.
Towards High-Resolution Copy-Evident Ceramic Tiles: A Deep Learning Framework for Halftoning and Watermarking
Authors: Lu Jianfeng , Wang Zhiwen , Li Li , Chang Ching-Chun , Luo Ting , Gu Wei
Published: July 2021

Ceramic art is essential in interior design and decoration, and making exquisite ceramic tiles imposes strict requirements for inkjet printing technology. High-resolution ceramic tiles are often produced through inkjet printing, in which the input images are converted into a halftone format. However, traditional binary halftoning techniques cannot produce high-resolution images for the ensuing printing process. Given that the processes of inkjet printing and high-temperature firing of ceramic tiles are a highly complex nonlinear system, and existing halftoning methods pose intractable problems, including inconsistent textures and color deviations. Based on a modified U-Net model and a modified error diffusion algorithm, we propose a multilevel halftoning method, which is capable of converting color-separation images of ceramic tiles into high-resolution halftone images. To deter copyright infringement, we further apply an ad hoc invisible watermarking method for halftone images. In this paper, we propose a four-stage framework: (1) A self-built dataset is used to solve non-convergence and overfitting problems caused by the unbalanced samples and non-uniqueness of halftone images. (2) A modified U-Net model is trained on the self-built dataset and applied to the ceramic-tile images. (3) An improved error diffusion algorithm is used to calibrate and convert the predicted continuous-tone transition images into multilevel halftone images for inkjet printing. (4) A invisible and robust watermark is embedding algorithm towards halftone images is proposed for copyright protection. Experimental results show that our methodology is effective for performing the color-to-halftone transformation and identifying the copyright.
Selective Code Duplication for Soft Error Protection on VLIW Architectures
Authors: Ko Yohan , Kim Soohwan , Kim Hyunchoong , Lee Kyoungwoo
Published: July 2021

Very Long Instruction Word, or VLIW, architectures have received much attention in specific-purpose applications such as scientific computation, digital signal processing, and even safety-critical systems. Several compilation techniques for VLIW architectures have been proposed in order to improve the performance, but there is a lack of research to improve reliability against soft errors. Instruction duplication techniques have been proposed by exploiting unused instruction slots (i.e., NOPs) in VLIW architectures. All the instructions cannot be replicated without additional code lines. Additional code lines are required to increase the number of duplicated instructions in VLIW architectures. Our experimental results show that 52% performance overhead as compared to unprotected source code when we duplicate all the instructions. This considerable performance overhead can be inapplicable for resource-constrained embedded systems so that we can limit the number of additional NOP instructions for selective protection. However, the previous static scheme duplicates instructions just in sequential order. In this work, we propose packing-oriented duplication to maximize the number of duplicated instructions within the same peroformance overhead bounds. Our packing-oriented approach can duplicate up to 18% more instructions within the same performance overheads compared to the previous static duplication techniques.