bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Influence of Silica Fume (SF) on the Rheology, Fluidity, Stability, Time-Varying Characteristics, and Mechanism of Cement Paste
Authors: Liu Hengrui , Sun Xiao , Wang Yao , Lu Xueying , Du Hui , Tian Zhenghong
Published: December 2021

In this study, the rheology, fluidity, stability, and time-varying properties of cement paste with different substitute contents of silica fume (SF) were investigated. The result showed that the effects of SF on macro-fluidity and micro-rheological properties were different under different water–cement ratios. The addition of SF increased the yield stress and plastic viscosity in the range of 2.61–18.44% and 6.66–24.66%, respectively, and reduced the flow expansion in the range of 4.15–18.91%. The effect of SF on cement paste gradually lost its regularity as the w/c ratio increased. The SF can effectively improve the stability of cement paste, and the reduction range of bleeding rate was 0.25–4.3% under different water–cement ratios. The mathematical models of rheological parameters, flow expansion, and time followed the following equations: τ(t) = τ0 + k0t, η(t) = η0eat, and L(t) = L0 − k1t, L(t) = L0 − k1t − a1t2. The SF slowly increased the rheological parameters in the initial time period and reduced the degree of fluidity attenuation, but the effect was significantly enhanced after entering the accelerated hydration period. The mechanism of the above results was that SF mainly affected the fluidity and rheology of the paste through the effect of water film thickness. The small density of SF particles resulted in a low sedimentation rate in the initial suspended paste, which effectively alleviated the internal particle agglomeration effect and enhanced stability. The SF had a dilution effect and nucleation effect during hydration acceleration, and the increase of hydration products effectively increased the plastic viscosity.
Atomistic Simulation of Microstructural Evolution of Ni50.8Ti Wires during Torsion Deformation
Authors: Liu Shan , Lin Yao , Wu Tao , Wang Guangchun
Published: December 2021

To explore the microstructural evolution of Ni50.8Ti wires during torsion deformation, single and polycrystalline models with various grain sizes (d = 9 nm, 5.6 nm, and 3.4 nm) were established on an atomic scale to explore their grain morphology evolution, stress-induced martensitic transformation, and dislocation movement. The results indicated that the grains were rotated and elongated to form long strips of grains during the torsion simulation. With the increase in torsion deformation, the elongated grains were further split, forming smaller grains. Stress-induced martensitic transformation took place and the martensite preferentially nucleated near the grain boundary, resulting in the formation of 30% austenites and 50% martensites. Additionally, a certain number of dislocations were generated during the torsion simulation. Under a low degree of torsion deformation, the main mechanism of plastic deformation was dislocation movement, while with a large degree of torsion deformation, the main mechanism of plastic deformation was grain rotation.
Characterization of Porous Scaffolds Fabricated by Joining Stacking Based Laser Micro-Spot Welding (JS-LMSW) for Tissue Engineering Applications
Authors: Cedeño-Viveros Luis D. , Rodriguez Ciro A. , Segura-Ibarra Victor , Vázquez Elisa , García-López Erika
Published: December 2021

A novel manufacturing approach was used to fabricate metallic scaffolds. A calibration of the laser cutting process was performed using the kerf width compensation in the calculations of the tool trajectory. Welding defects were studied through X-ray microtomography. Penetration depth and width resulted in relative errors of 9.4%, 1.0%, respectively. Microhardness was also measured, and the microstructure was studied in the base material. The microhardness values obtained were 400 HV, 237 HV, and 215 HV for the base material, HAZ, and fusion zone, respectively. No significant difference was found between the microhardness measurement along with different height positions of the scaffold. The scaffolds’ dimensions and porosity were measured, their internal architecture was observed with micro-computed tomography. The results indicated that geometries with dimensions under 500 µm with different shapes resulted in relative errors of ~2.7%. The fabricated scaffolds presented an average compressive modulus ~13.15 GPa, which is close to cortical bone properties. The proposed methodology showed a promising future in bone tissue engineering applications.
Dynamic Response of Polyindole Coated Zinc Ferrite Particle Suspension under an Electric Field
Authors: Kang Su Hyung , Choi Hyoung Jin
Published: December 2021

ZnFe2O4 particles initially synthesized through a simple solvothermal method were coated using polyindole (PIn) to prepare an actively controllable core-shell typed hybrid material under both electric and magnetic fields. An advantage of this process is not needing to add the stabilizers or surfactants commonly used for uniform coating when synthesizing core or shell-structured particles. The synthesized ZnFe2O4/PIn particles have a lower density than conventional magnetic particles and have suitable properties as electrorheological (ER) particles. The expected spherical shape of the particles was proven using both scanning electron microscopy and transmission electron microscopy. The chemical characterization was performed using Fourier-transform infrared spectroscopy and X-ray diffraction analysis. To analyze the rheological properties, a ZnFe2O4/PIn based suspension was prepared, and dynamic rheological measurements were performed for different electric field strengths using a rotary rheometer. Both dynamic and elastic yield stresses of the ER fluid had a slope of 1.5, corresponding to the conductivity model. Excellent ER effect was confirmed through rheological analysis, and the prepared ER fluid had a reversible and immediate response to repeated electric fields.
Chemical Properties of Human Dentin Blocks and Vertical Augmentation by Ultrasonically Demineralized Dentin Matrix Blocks on Scratched Skull without Periosteum of Adult-Aged Rats
Authors: Zhu Bowen , Yokozeki Kenji , Kabir Md. Arafat , Todoh Masahiro , Akazawa Toshiyuki , Murata Masaru
Published: December 2021

Vertical augmentation is one of the most challenging techniques in bone engineering. Several parameters, such mechano-chemical characteristics, are important to optimize vertical bone regeneration using biomaterials. The aims of this study were to chemically characterize human dentin blocks (calcified demineralized dentin matrix: CDM, partially demineralized dentin matrix: PDDM and completely demineralized dentin matrix: CDDM) (2 × 2 × 1 mm3) chemically and evaluate the behavior of PDDM blocks on non-scratched or scratched skulls without periosteum of adult rats (10–12 months old, female) as a vertical augmentation model. The dissolved efficiency of CDM showed 32.3% after ultrasonic demineralization in 1.0 L of 2% HNO3 for 30 min. The 30 min-demineralized dentin was named PDDM. The SEM images of PDDM showed the opening of dentinal tubes, nano-microcracks and the smooth surface. In the collagenase digestion test, the weight-decreasing rates of CDM, PDDM and CDDM were 9.2%, 25.5% and 78.3% at 12 weeks, respectively. CDM inhibited the collagenase digestion, compared with PDDM and CDDM. In the PDDM onlay graft on an ultrasonically scratched skull, the bone marrow-space opening from original bone was found in the bony bridge formation between the human PDDM block and dense skull of adult senior rats at 4 and 8 weeks. On the other hand, in the cases of the marrow-space closing in both non-scratched skulls and scratched skulls, the bony bridge was not formed. The results indicated that the ultrasonic scratching into the compact parietal bone might contribute greatly to the marrow-space opening from skull and the supply of marrow cells, and then bony bridge formation could occur in the vertical augmentation model without a periosteum.
The Effect of Grain Orientation of β-Sn on Copper Pillar Solder Joints during Electromigration
Authors: Xu Kexin , Fu Xing , Wang Xinjie , Fu Zhiwei , Yang Xiaofeng , Chen Si , Shi Yijun , Huang Yun , Chen Hongtao
Published: December 2021

The grain orientation of Sn-based solder joints on copper pillars under the combined action of electron wind force and temperature gradient greatly affects their electromigration damage. The copper pillars with Sn-1.8Ag lead-free solder on the top was subjected to a current density of 1.5 × 104 A/cm2 at 125 °C to study the electromigration behaviors. The grain orientation was characterized by scanning electron microscopy (SEM) equipped with electron backscattered diffraction (EBSD) detector. Metal dissolution and voids formation in the cathode as well as massive intermetallic compounds(IMC) accumulation in the anode were observed after electromigration. Closer examination of solder joints revealed that the Sn grain whose c-axis perpendicular to electric current may have retarded Cu diffusion to anode and IMC accumulation. In addition, the newly formed Cu6Sn5 exhibited preferred orientation related to the electric current direction.
Nb/Sn Liquid-Solid Reactive Diffusion Couples and Their Application to Determination of Phase Equilibria and Interdiffusion Coefficients of Nb-Sn Binary System
Authors: Zhang Jiali , Zhong Jing , Li Qin , Zhang Lijun
Published: December 2021

Nb3Sn plays an irreplaceable role in superconducting parts due to its stable performance under high field conditions. Accurate phase equilibria and interdiffusion coefficients are of great significance for designing novel Nb3Sn superconductors. However, the related experimental information is still in a state of scarcity because of the difficulty in fabrication of Nb-Sn alloys caused by the large difference in melting points of Nb and Sn. In this paper, a simple but pragmatic approach was first proposed to prepare the Nb/Sn liquid-solid reactive diffusion couples (LSDCs) at 1100 °C and 1200 °C, of which the phase identification of the formed layer and the measurement of composition-distance profiles were conducted. The formed layer in Nb/Sn LSDCs was confirmed to be Nb3Sn compound. While the measured composition profiles were employed to determine the phase equilibria according to the local equilibrium hypothesis and the interdiffusion coefficients with an aid of the latest version of HitDIC software. The determined phase equilibria of Nb3Sn, (Nb) and liquid show good agreement with the assessed phase diagram. While the calculated interdiffusion coefficients and activation energy for diffusion in Nb3Sn are consistent with both experimental and theoretical data in the literature. Moreover, the growth of the formed Nb3Sn layer in Nb/Sn LSDCs was also found to be diffusion controlled. All the obtained phase equilibria and interdiffusion coefficients are of great value for further thermodynamic and kinetic modeling of the Nb-Sn system. Furthermore, it is anticipated that the presently proposed approach of fabricating liquid-solid reactive diffusion couple should serve as a general one for various alloy systems with large differences in melting points.
Fabrication of PDMS@Fe3O4/MS Composite Materials and Its Application for Oil-Water Separation
Authors: Wang Jiaqi , Fan Zhenzhong , Liu Qingwang , Tong Qilei , Wang Biao
Published: December 2021

The discharge of oily wastewater and oil spills at sea are the current difficulties in water pollution control. This problem often leads to terrible disasters. Therefore, the effective realization of oil-water separation is a very challenging problem. Superhydrophobic sponge is a promising oil-absorbing material. In this article, we reported a superhydrophobic sponge with nano-Fe3O4 for oil-water separation. The addition of nano-Fe3O4 allows the sponge to be recycled under the action of magnetic force. The sponge has the advantages of low cost, simple preparation and efficient oil-water separation. This kind of sponge is very worthy of promotion for the treatment of oily wastewater and marine oil spill accidents.
Identification of Grain Oriented SiFe Steels Based on Imaging the Instantaneous Dynamics of Magnetic Barkhausen Noise Using Short-Time Fourier Transform and Deep Convolutional Neural Network
Authors: Maciusowicz Michal , Psuj Grzegorz , Kochmański Paweł
Published: December 2021

This paper presents a new approach to the extraction and analysis of information contained in magnetic Barkhausen noise (MBN) for evaluation of grain oriented (GO) electrical steels. The proposed methodology for MBN analysis is based on the combination of the Short-Time Fourier Transform for the observation of the instantaneous dynamics of the phenomenon and deep convolutional neural networks (DCNN) for the extraction of hidden information and building the knowledge. The use of DCNN makes it possible to find even complex and convoluted rules of the Barkhausen phenomenon course, difficult to determine based solely on the selected features of MBN signals. During the tests, several samples made of conventional and high permeability GO steels were tested at different angles between the rolling and transverse directions. The influences of the angular resolution and the proposed additional prediction update algorithm on the DCNN accuracy were investigated, obtaining the highest gain for the angle of 3.6°, for which the overall accuracy exceeded 80%. The obtained results indicate that the proposed new solution combining time–frequency analysis and DCNN for the quantification of information from MBN having stochastic nature may be a very effective tool in the characterization of the magnetic materials.
Stiffener Design to Maintain Line Heating Efficiency during the Lifting Process Considering Phase Transformation
Authors: Noh Hong-Jun , Lim Hun-Bong , Yoon Hee-Chan , Han Young-Hwan , Yang Hyun-Ik
Published: December 2021

In the shipbuilding industry, welding is the main technique used to join steel structures. There is a lifting process, post-welding, that can eliminate the correction effect of line heating. Line heating is reperformed after the lifting process. This can significantly delay the ship assembly process. Herein, we present a design method for installing a permanent stiffener to avoid the disappearance of the line heating effect during the lifting process. The change in physical properties due to heating and cooling of the line heating is calculated. The limiting stress, at which the effect of the line heating completely disappears, based on the inherent strain theory, is obtained. The phase fraction by the cooling rate is calculated using the continuous cooling transformation diagram and the Kiustinen–Marburgerm equation. Physical properties affected by the phase transformation are calculated, considering the physical properties and fraction of each phase. The square plate theory and superposition principle are used to construct a local model, with a stiffener, of the ship block. The stress caused by the shape of the stiffener and the distance between the stiffeners were calculated for the local model. The calculated stress and the limiting stress were compared to determine, for the expected line heating efficiency, the most acceptable stiffener design. Finally, to confirm the elimination of the problem, the designed stiffener is analyzed using the finite element method.
Preparation of Stable Phase Change Material Emulsions for Thermal Energy Storage and Thermal Management Applications: A Review
Authors: Liu Liu , Niu Jianlei , Wu Jian-Yong
Published: December 2021

Thermal energy storage (TES) is an important means for the conservation and efficient utilization of excessive and renewable energy. With a much higher thermal storage capacity, latent heat storage (LHS) may be more efficient than sensible heat storage. Phase change materials (PCMs) are the essential storage media for LHS. PCM emulsions have been developed for LHS in flow systems, which act as both heat transfer and thermal storage media with enhanced heat transfer, low pumping power, and high thermal storage capacity. However, two major barriers to the application of PCM emulsions are their instability and high degree of supercooling. To overcome these, various strategies have been attempted, such as the reduction of emulsion droplet size, addition of nucleating agents, and optimization of the formulation. To the best of our knowledge, however, there is still a lack of review articles on fabrication methods for PCM emulsions or their latest applications. This review was to provide an up-to-date and comprehensive summary on the effective strategies and the underlying mechanisms for the preparation of stable PCM emulsions and reduction of supercooling, especially with the organic PCMs of paraffin. It was also to share our insightful perspectives on further development and potential applications of PCM emulsions for efficient energy storage.
Study on the Evolution of Graphene Defects and the Mechanical and Thermal Properties of GNPs/Cu during CVD Repair Process
Authors: Xiu Ziyang , Ju Boyu , Duan Cungao , Fu Sen , Zhang Ningbo , Mei Yong , Liu Jinming , Feng Yuhan , Yang Wenshu , Kang Pengchao
Published: December 2021

Graphene has extremely high theoretical strength and electrothermal properties, and its application to Cu-based composites is expected to achieve a breakthrough in the performance of existing composites. As a nano-reinforced body, graphene often needs a long time of ball milling to make it uniformly dispersed, but the ball milling process inevitably brings damage to the graphene, causing the performance of the composite to deviate from expectations. Therefore, this paper uses CH4 as a carbon source to repair graphene through a CVD process to prepare low-damage graphene/Cu composites. The process of graphene defect generation was studied through the ball milling process. The effects of defect content and temperature on the graphene repair process were studied separately. The study found that the graphene defect repair process, the decomposition process of oxygen-containing functional groups, and the deposition process of active C atoms existed simultaneously in the CVD process. When the repair temperature was low, the C atom deposition process and the oxygen-containing functional group decomposition process dominated. In addition, when the repair temperature is high, the graphene defect repair process dominated. 3 wt% graphene/Cu composites were prepared by pressure infiltration, and it was found that the bending strength was increased by 48%, the plasticity was also slightly increased, and the thermal conductivity was increased by 10–40%. This research will help reduce graphene defects, improve the intrinsic properties of graphene, and provide theoretical guidance for the regulation of C defects in composites.
Search Graph Magnification in Rapid Mixing of Markov Chains Associated with the Local Search-Based Metaheuristics
Authors: Shenoy Ajitha K. B. , Pai Smitha N.
Published: December 2021

The structural property of the search graph plays an important role in the success of local search-based metaheuristic algorithms. Magnification is one of the structural properties of the search graph. This study builds the relationship between the magnification of a search graph and the mixing time of Markov Chain (MC) induced by the local search-based metaheuristics on that search space. The result shows that the ergodic reversible Markov chain induced by the local search-based metaheuristics is inversely proportional to magnification. This result indicates that it is desirable to use a search space with large magnification for the optimization problem in hand rather than using any search spaces. The performance of local search-based metaheuristics may be good on such search spaces since the mixing time of the underlying Markov chain is inversely proportional to the magnification of search space. Using these relations, this work shows that MC induced by the Metropolis Algorithm (MA) mixes rapidly if the search graph has a large magnification. This indicates that for any combinatorial optimization problem, the Markov chains associated with the MA mix rapidly i.e., in polynomial time if the underlying search graph has large magnification. The usefulness of the obtained results is illustrated using the 0/1-Knapsack Problem, which is a well-studied combinatorial optimization problem in the literature and is NP-Complete. Using the theoretical results obtained, this work shows that Markov Chains (MCs) associated with the local search-based metaheuristics like random walk and MA for 0/1-Knapsack Problem mixes rapidly.
Mussel Shells, a Valuable Calcium Resource for the Pharmaceutical Industry
Authors: Mititelu Magdalena , Stanciu Gabriela , Drăgănescu Doina , Ioniță Ana Corina , Neacșu Sorinel Marius , Dinu Mihaela , Stefan-van Staden Raluca-Ioana , Moroșan Elena
Published: December 2021

(1) Background: The mussel (Mytilus edulis, Mytilus galloprovincialis) is the most widespread lamellibranch mollusk, being fished on all coasts of the European seas. Mussels are also widely grown in Japan, China, and Spain, especially for food purposes. This paper shows an original technique for mussel shell processing for preparation of calcium salts, such as calcium levulinate. This process involves synthesis of calcium levulinate by treatment of Mytilus galloprovincialis shells with levulinic acid. The advantage of mussel shell utilization results in more straightforward qualitative composition. Thus, the weight of the mineral component lies with calcium carbonate, which can be used for extraction of pharmaceutical preparations. (2) Methods: Shell powder was first deproteinized by calcination, then the mineral part was treated with levulinic acid. The problem of shells generally resulting from the industrialization of marine molluscs creates enough shortcomings, if one only mentions storage and handling. One of the solutions proposed by us is the capitalization of calcium from shells in the pharmaceutical industry. (3) Results: The toxicity of calcium levulinate synthesized from the mussel shells was evaluated by the method known in the scientific literature as the Constantinescu phytobiological method (using wheat kernels, Triticum vulgare Mill). Acute toxicity of calcium levulinate was evaluated; the experiments showed the low toxicity of calcium levulinate. (4) Conclusion: The experimental results highlighted calcium as the predominant element in the composition of mussel shells, which strengthens the argument of capitalizing the shells as an important natural source of calcium.
Semi-Synthesis, Cytotoxic Evaluation, and Structure—Activity Relationships of Brefeldin A Derivatives with Antileukemia Activity
Authors: Lu Xu-Xiu , Jiang Yao-Yao , Wu Yan-Wei , Chen Guang-Ying , Shao Chang-Lun , Gu Yu-Cheng , Liu Ming , Wei Mei-Yan
Published: December 2021

Brefeldin A (1), a potent cytotoxic natural macrolactone, was produced by the marine fungus Penicillium sp. (HS-N-29) from the medicinal mangrove Acanthus ilicifolius. Series of its ester derivatives 2–16 were designed and semi-synthesized, and their structures were characterized by spectroscopic methods. Their cytotoxic activities were evaluated against human chronic myelogenous leukemia K562 cell line in vitro, and the preliminary structure–activity relationships revealed that the hydroxy group played an important role. Moreover, the monoester derivatives exhibited stronger cytotoxic activity than the diester derivatives. Among them, brefeldin A 7-O-2-chloro-4,5-difluorobenzoate (7) exhibited the strongest inhibitory effect on the proliferation of K562 cells with an IC50 value of 0.84 µM. Further evaluations indicated that 7 induced cell cycle arrest, stimulated cell apoptosis, inhibited phosphorylation of BCR-ABL, and thereby inactivated its downstream AKT signaling pathway. The expression of downstream signaling molecules in the AKT pathway, including mTOR and p70S6K, was also attenuated after 7-treatment in a dose-dependent manner. Furthermore, molecular modeling of 7 docked into 1 binding site of an ARF1–GDP-GEF complex represented well-tolerance. Taken together, 7 had the potential to be served as an effective antileukemia agent or lead compound for further exploration.
Predictors of Epicardial Fat Volume Decrease after Dapagliflozin Treatment in Patients with Type 2 Diabetes
Authors: Braha Adina , Albai Alin , Timar Bogdan , Cipu Daniela , Vasiluță Lucian , Potre Ovidiu , Timar Romulus
Published: December 2021

Background and Objectives: Dapagliflozin treatment proved to reduce the epicardial fat volume (EFV) in patients with type 2 diabetes (T2D). Despite the reduction in EFV being associated with improved diastolic function in patients with T2D, EVF is not routinely evaluated in T2D because it is costly and involves radiation exposure. This study aims to identify biomarkers that predict EFV reduction after dapagliflozin treatment in patients with T2D. Materials and Methods: In a prospective, observational, consecutive-case enrollment scenario, 52 patients with T2D were initiated on dapagliflozin 10 mg q.d. as part of the standard of care. At enrollment and after six months of dapagliflozin treatment, patients were evaluated using cardiac ultrasonography, native computer tomography, transient liver elastography, and metabolic lab tests. In addition, the atherogenic index of plasma (AIP), atherogenic coefficient (AC), triglyceride glucose index (TyG), cardiac risk ratio (CRR), and visceral abdominal index (VAI) were calculated. Results: Higher AIP (r = 0.28; p = 0.04), CRR (r = 0.28; p = 0.04), and TyG (r = 0.32; p = 0.01) are associated with more important reductions in the EFV. A lower conicity index (β = −0.29; p = 0.03), visceral fat volume at the 4th vertebrae (L4VFV) (β = −0.32; p = 0.02), left atrium volume (β = −3.08; p = 0.003), and right ventricle diameter (β = −2.13; p = 0.04) are associated with higher reductions in the EFV after six months of dapagliflozin treatment. A valid performance for predicting clinically relevant decreases in EFV after dapagliflozin treatment was observed for AIP (AUROC = 0.903; Youden = 0.732; p < 0.001), CRR (AUROC = 0.772; Youden = 0.595; p = 0.004), TyG (AUROC = 0.957; Youden = 0.904; p < 0.001), and VAI (AUROC = 0.898; Youden = 0.712; p < 0.001). Conclusion: Higher initial EFV values are associated with more important reductions in EFV in patients with T2D treated for six months with dapagliflozin. TyG values have the best prediction performances for EFV reduction, having the highest sum of sensitivity and specificity at the 0.904 threshold level. AIP, CRR, VAI, conicity index, L4VF, left atrium volume, and right ventricle volume are valid biomarkers for a decrease in EFV after dapagliflozin treatment in diabetes patients.
Is Long-Term Survival in Metastases from Neuroendocrine Neoplasms Improved by Liver Resection?
Authors: Kraft Alin , Croitoru Adina , Moldovan Cosmin , Lupescu Ioana , Tomescu Dana , Purnichescu-Purtan Raluca , Herlea Vlad , Popescu Irinel , Botea Florin
Published: December 2021

Background and Objectives: Although many of the neuroendocrine neoplasms (NEN) have a typically prolonged natural history compared with other gastrointestinal tract cancers, at least 40% of patients develop liver metastases. This study aims to identify whether liver resection improves the overall survival of patients with liver metastases from NEN. Materials and Methods: We conducted a retrospective study at “Fundeni” Clinical Institute over a time period of 15 years; we thereby identified a series of 93 patients treated for NEN with liver metastases, which we further divided into 2 groups as follows: A (45 patients) had been subjected to liver resection complemented by systemic therapies, and B (48 patients) underwent systemic therapy alone. To reduce the patient selection bias we performed at first a propensity score matching. This was followed by a bootstrapping selection with Jackknife error correction, with the purpose of getting a statistically illustrative sample. Results: The overall survival of the matched virtual cohort under study was 41 months (95% CI 37–45). Group A virtual matched patients showed a higher survival rate (52 mo., 95% CI: 45–59) than B (31 mo., 95% CI: 27–35), (p < 0.001, Log-Rank test). Upon multivariate analysis, seven independent factors were identified to have an influence on survival: location (midgut) and primary tumor grading (G3), absence of concomitant LM, number (2–4), location (unilobar), grading (G3) of LM, and 25–50% hepatic involvement at the time of the metastatic disease diagnosis. Conclusions: Hepatic resection is nowadays the main treatment providing potential cure and prolonged survival, for patients with NEN when integrated in a multimodal strategy based on systemic therapy.
Three-Dimensional Transesophageal Echocardiography in the Diagnosis and Treatment of Mitral Prosthetic Valve Endocarditis—A Narrative Review
Authors: Carević Vedran , Mladenović Zorica , Perković-Avelini Ružica , Bečić Tina , Radić Mislav , Fabijanić Damir
Published: December 2021

Despite advances in diagnosis, imaging methods, and medical and surgical interventions, prosthetic valve endocarditis (PVE) remains an extremely serious and potentially fatal complication of heart valve surgery. Characteristic changes of PVE are more difficult to detect by transthoracic echocardiography (TTE) than those involving the native valve. We reviewed advances in transesophageal echocardiography (TEE) in the diagnosis of PVE. Three-dimensional (3D) TEE is becoming an increasingly available imaging method combined with two-dimensional TEE. It contributes to faster and more accurate diagnosis of PVE, assessment of PVE-related complications, monitoring effectiveness of antibiotic treatment, and determining optimal time for surgery, sometimes even before or without previous TTE. In this article, we present advances in the treatment of patients with mitral PVE due to 3D TEE application.
Bibliometric Study of Scientific Productivity on the Impacts on Mental Health in Times of Pandemic
Authors: Caballero-Apaza Luz Marina , Vidal-Espinoza Rubén , Curaca-Arroyo Silvia , Gomez-Campos Rossana , Callata-Gallegos Zaida , Fuentes-López José , Cossio-Bolaños Marco
Published: December 2021

Background and Objectives: The presence of the new SARS-CoV-2 virus is causing enormous threats to people’s health and lives, so quantifying the scientific productivity on mental health in times of pandemic is an urgent need, especially to expand the degree of knowledge on mental health problems in regions of low scientific productivity. The aim was to characterize the bibliometric indicators of scientific productivity on mental health during the pandemic in the PubMed Identifier database of the National Library of Medicine in the United States. Materials and Methods: A documentary study (bibliometric) of the scientific productivity on mental health in times of pandemic from January 2020 to June 2021 was carried out. The PubMed database was used to abstract the information from the original scientific articles. The data abstracted were: authors, year of publication, journal name, country, and language of publication. Results: We identified 47 original articles worldwide, which were published in 29 journals and in three languages (English, Spanish, and German). We observed three groups of countries that published on mental health topics. The first group comprised the largest number of publications, which were multicenter studies (six studies), followed by India (five studies), and Italy (four studies). A second group comprised Bangladesh, China, USA, and Spain, with 3 studies each; and a third group comprised 13 countries (Albania, Saudi Arabia, Argentina, Brazil, South Korea, Denmark, Ecuador, Egypt, Greece, Japan, Jordan, Kuwait, and New Zealand) with one study each. Conclusions: Bibliometric indicators of scientific productivity on mental health during the COVID-19 pandemic have ostensibly increased. We verified 47 studies in PubMed, which could serve to improve the understanding and management of COVID-19, as well as serve as a thought-provoking means for other countries and researchers to publish on the state of mental health during and post pandemic.
Hydroethanolic Extract of Defatted Buchholzia coriacea Seeds Alleviates Tamoxifen-Induced Hepatic Triglyceride Accumulation, Inflammation and Oxidative Distress in Rat
Authors: Ore Ayokanmi , Adeogun Abideen Idowu , Akinloye Oluseyi Adeboye
Published: December 2021

Background: Tamoxifen (TMX) has proven to be effective in the prevention and treatment of breast cancer. However, long-term use of TMX is associated with hepatic steatosis, oxidative liver injury and hepatocarcinoma. Buchholzia coriacea seeds (BCS) have been widely applied in traditional medicine due to their nutritional and therapeutic potentials. This study investigates the protective effect of hydroethanolic extract of (defatted) B. coriacea seeds (HEBCS) against TMX–induced hepatotoxicity in rats. Methods: Thirty-six (36) male albino rats were divided into six groups (n = 6/group). Group I served as control. Group II received 50 mg/kg/day TMX orally (p.o.) (TMX) for 21 days, group III received TMX plus 125 mg/kg/d HEBCS p.o. (HEBCS 125) for 21 days, group IV received TMX plus 250 mg/kg/d HEBCS p.o. (HEBCS 250) for 21 days and rats in group V and VI received HEBCS 125 and HEBCS 250 respectively for 21 days. Results: Compared with the control, TMX caused a significant increase (p < 0.05) in serum hepatic function biomarkers: alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase by 57%, 60% and 68% respectively. TMX also caused a significant increase in hepatic triglycerides level by 166% when compared with control and a significant decrease in serum HDL-cholesterol level by 37%. Compared with control, hepatic marker of inflammation, tumour necrosis factor alpha (TNF-α) increased significantly by 220%, coupled with significant increase in expression of interleukin 6 and cyclooxygenase 2. There was also significant increase in levels of Biomarkers of oxidative stress, nitric oxide, malondialdehyde and protein carbonyls in the TMX group by 89%, 175% and 114% respectively when compared with the control. Hepatic antioxidants, reduced glutathione (GSH) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GSH-Px) decreased significantly in the TMX group by 35%, 67%, 41%, 59% and 53% respectively when compared with the control. However, HEBCS at 250 mg/kg significantly protected against TMX–induced hepatotoxicity by decreasing hepatic triglyceride content, serum hepatic function biomarkers, hepatic inflammation and oxidative stress with significant improvement in hepatic antioxidant system. Histopathological findings show that HEBCS alleviate TMX–induced hepatocyte ballooning. Conclusions: Current data suggest that HEBCS protected against TMX–induced hepatotoxicity in rats. HEBCS may be useful in managing TMX–induced toxicities in breast cancer patients. It may also be helpful against other forms of liver injury involving steatosis, inflammation, free radicals, and oxidative damage.
Nitric Oxide: The Missing Factor in COVID-19 Severity?
Authors: Nikolaidis Alexandros , Kramer Ron , Ostojic Sergej
Published: December 2021

Coronavirus disease 2019 (COVID-19) is a contagious respiratory and vascular disease that continues to spread among people around the world, mutating into new strains with increased transmission rates, such as the delta variant. The scientific community is struggling to discover the link between negative COVID-19 outcomes in patients with preexisting conditions, as well as identify the cause of the negative clinical patient outcomes (patients who need medical attention, including hospitalization) in what seems like a widespread range of COVID-19 symptoms that manifest atypically to any preexisting respiratory tract infectious diseases known so far. Having successfully developed a nutritional formulation intervention based on nitrate, a nitric oxide precursor, the authors hypothesis is that both the comorbidities associated with negative clinical patient outcomes and symptoms associated with COVID-19 sickness are linked to the depletion of a simple molecule: nitric oxide.
Thermodynamic Limitations and Exergy Analysis of Brackish Water Reverse Osmosis Desalination Process
Authors: Alsarayreh Alanood , Al-Obaidi Mudhar , Ruiz-García Alejandro , Patel Raj , Mujtaba Iqbal
Published: December 2021

The reverse osmosis (RO) process is one of the most popular membrane technologies for the generation of freshwater from seawater and brackish water resources. An industrial scale RO desalination consumes a considerable amount of energy due to the exergy destruction in several units of the process. To mitigate these limitations, several colleagues focused on delivering feasible options to resolve these issues. Most importantly, the intention was to specify the most units responsible for dissipating energy. However, in the literature, no research has been done on the analysis of exergy losses and thermodynamic limitations of the RO system of the Arab Potash Company (APC). Specifically, the RO system of the APC is designed as a medium-sized, multistage, multi pass spiral wound brackish water RO desalination plant with a capacity of 1200 m3/day. Therefore, this paper intends to fill this gap and critically investigate the distribution of exergy destruction by incorporating both physical and chemical exergies of several units and compartments of the RO system. To carry out this study, a sub-model of exergy analysis was collected from the open literature and embedded into the original RO model developed by the authors of this study. The simulation results explored the most sections that cause the highest energy destruction. Specifically, it is confirmed that the major exergy destruction happens in the product stream with 95.8% of the total exergy input. However, the lowest exergy destruction happens in the mixing location of permeate of the first pass of RO desalination system with 62.28% of the total exergy input.
Novel Mixed Matrix Membranes Based on Polymer of Intrinsic Microporosity PIM-1 Modified with Metal-Organic Frameworks for Removal of Heavy Metal Ions and Food Dyes by Nanofiltration
Authors: Kuzminova Anna , Dmitrenko Mariia , Zolotarev Andrey , Korniak Aleksandra , Poloneeva Daria , Selyutin Artem , Emeline Alexei , Yushkin Alexey , Foster Andrew , Budd Peter , Ermakov Sergey
Published: December 2021

Nowadays, nanofiltration is widely used for water treatment due to its advantages, such as energy-saving, sustainability, high efficiency, and compact equipment. In the present work, novel nanofiltration membranes based on the polymer of intrinsic microporosity PIM-1 modified by metal-organic frameworks (MOFs)—MIL-140A and MIL-125—were developed to increase nanofiltration efficiency for the removal of heavy metal ions and dyes. The structural and physicochemical properties of the developed PIM-1 and PIM-1/MOFs membranes were studied by the spectroscopic technique (FTIR), microscopic methods (SEM and AFM), and contact angle measurement. Transport properties of the developed PIM-1 and PIM-1/MOFs membranes were evaluated in the nanofiltration of the model and real mixtures containing food dyes and heavy metal ions. It was found that the introduction of MOFs (MIL-140A and MIL-125) led to an increase in membrane permeability. It was demonstrated that the membranes could be used to remove and concentrate the food dyes and heavy metal ions from model and real mixtures.
Coupling Bulk Phase Separation of Disordered Proteins to Membrane Domain Formation in Molecular Simulations on a Bespoke Compute Fabric
Authors: Shillcock Julian C. , Thomas David B. , Beaumont Jonathan R. , Bragg Graeme M. , Vousden Mark L. , Brown Andrew D.
Published: December 2021

Phospholipid membranes surround the cell and its internal organelles, and their multicomponent nature allows the formation of domains that are important in cellular signalling, the immune system, and bacterial infection. Cytoplasmic compartments are also created by the phase separation of intrinsically disordered proteins into biomolecular condensates. The ubiquity of lipid membranes and protein condensates raises the question of how three-dimensional droplets might interact with two-dimensional domains, and whether this coupling has physiological or pathological importance. Here, we explore the equilibrium morphologies of a dilute phase of a model disordered protein interacting with an ideal-mixing, two-component lipid membrane using coarse-grained molecular simulations. We find that the proteins can wet the membrane with and without domain formation, and form phase separated droplets bound to membrane domains. Results from much larger simulations performed on a novel non-von-Neumann compute architecture called POETS, which greatly accelerates their execution compared to conventional hardware, confirm the observations. Reducing the wall clock time for such simulations requires new architectures and computational techniques. We demonstrate here an inter-disciplinary approach that uses real-world biophysical questions to drive the development of new computing hardware and simulation algorithms.
Incorporation of Lipids into Wheat Bran Cellulose/Wheat Gluten Composite Film Improves Its Water Resistance Properties
Authors: Shen Guanghui , Yu Guoxian , Wu Hejun , Li Shanshan , Hou Xiaoyan , Li Meiliang , Li Qingye , Liu Xingyan , Zhou Man , Chen Anjun , Zhang Zhiqing
Published: December 2021

This work evaluated the improvement effects of lipids incorporation on water resistance of composite biodegradable film prepared with wheat bran cellulose/wheat gluten (WBC/WG) using an alkaline–ethanol film forming system. Four types of lipids, paraffin wax (PW), beeswax (BW), paraffin oil (PO), and oleic acid (OA), were tested. We found that PW, BW, and PO incorporation at 5–20% improved water vapor permeability (WVP) and surface hydrophobicity of prepared films. Particularly, incorporation of 15% BW could best improve the water resistance properties of the film, with the lowest WVP of 0.76 × 10−12 g/cm·s·Pa and largest water contact angle (WCA) of 86.18°. Incorporation of OA led to the decline in moisture barrier properties. SEM images revealed that different lipids incorporation changed the morphology and of the composite film, and cross-sectional morphology indicated BW-incorporated film obtained more uniform and compact structures compared to other films. Moreover, Fourier transform infrared spectra indicated that the incorporation of PW or BW enhanced the molecular interactions between the film components, confirmed by the chemical shift of characteristic peaks at 3277 and 1026 cm−1. Differential scanning calorimetry results revealed that incorporation of PW, BW, and PO increased films’ melting point, decomposition temperatures, and enthalpy values. Furthermore, the presence of most lipids decreased tensile strength and elongation at the break of the film. Overall, the composite film containing 15% BW obtained the most promising water resistance performance and acceptable mechanical properties, and it thus most suitable as a hydrophobic biodegradable material for food packaging.
Solid-State Welding of the Nanostructured Ferritic Alloy 14YWT Using a Capacitive Discharge Resistance Welding Technique
Authors: Lear Calvin Robert , Gigax Jonathan Gregory , Schneider Matthew M. , Steckley Todd Edward , Lienert Thomas J. , Maloy Stuart Andrew , Eftink Benjamin Paul
Published: December 2021

Joining nanostructured ferritic alloys (NFAs) has proved challenging, as the nano-oxides that provide superior strength, creep resistance, and radiation tolerance at high temperatures tend to agglomerate, redistribute, and coarsen during conventional fusion welding. In this study, capacitive discharge resistance welding (CDRW)—a solid-state variant of resistance welding—was used to join end caps and thin-walled cladding tubes of the NFA 14YWT. The resulting solid-state joints were found to be hermetically sealed and were characterized across the weld region using electron microscopy (macroscopic, microscopic, and nanometer scales) and nanoindentation. Microstructural evolution near the weld line was limited to narrow (~50–200 μm) thermo-mechanically affected zones (TMAZs) and to a reduction in pre-existing component textures. Dispersoid populations (i.e., nano-oxides and larger oxide particles) appeared unchanged by all but the highest energy and power CDRW condition, with this extreme producing only minor nano-oxide coarsening (~2 nm → ~5 nm Ø). Despite a minimal microstructural change, the TMAZs were found to be ~10% softer than the surrounding base material. These findings are considered in terms of past solid-state welding (SSW) efforts—cladding applications and NFA-like materials in particular—and in terms of strengthening mechanisms in NFAs and the potential impacts of localized temperature–strain conditions during SSW.
Laser Shock Peening of Ti6Al4V Alloy with Combined Nanosecond and Femtosecond Laser Pulses
Authors: Sun Rujian , He Guangzhi , Bai Hailin , Yan Jianfeng , Guo Wei
Published: December 2021

Laser shock peening (LSP) with nanosecond or femtosecond laser pulses is applied to improve the mechanical properties of metallic materials. Thus, it is necessary to compare the effects of different processing methods on microstructure changes and property improvement. In this study, nanosecond LSP (NLSP), femtosecond LSP (FLSP), and LSP with combined nanosecond and femtosecond laser pulses (F-NLSP) are conducted on Ti6Al4V alloys to compare the surface morphologies, in-depth microstructures, and nanohardness changes. In FLSP, the peened surface is smooth, and the affected depth is limited near the peened surface. NLSPed and F-NLSPed samples present rough surfaces due to the severe ablation process. Small equiaxed grains with no preferred grain orientation are denser in F-NLSPed samples than that in NLSPed samples. Compared with NLSPed samples, the affected depth and amplitude of in-depth nanohardness are larger in F-NLSPed samples. This is attributed to the increased laser absorption of incident laser on the treated surface by femtosecond laser pulses. The results in this study show the effects of different LSP methods and provide chances in engineering potentials for material property improvements.
Transcriptome Analysis of Arbuscular Mycorrhizal Casuarina glauca in Damage Mitigation of Roots on NaCl Stress
Authors: Wang Yihan , Dong Fengxin , Tang Ming
Published: December 2021

Casuarina glauca grows in coastal areas suffering long-term damage due to high salt stress. Arbuscular mycorrhizal fungi (AMF) can colonize their roots to alleviate the effects of salt stress. However, the specific molecular mechanism still needs to be further explored. Our physiological and biochemical analysis showed that Rhizophagus irregularis inoculation played an important role in promoting plant growth, regulating ion balance, and changing the activity of antioxidant enzymes. Transcriptome analysis of roots revealed that 1827 differentially expressed genes (DEGs) were affected by both R. irregularis inoculation and NaCl stress. The enrichment of GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) showed that most of these DEGs were significantly enriched in ion transport, antioxidant enzyme activity, carbohydrate metabolism, and cell wall. HAK5, KAT3, SKOR, PIP1-2, PER64, CPER, GLP10, MYB46, NAC43, WRKY1, and WRKY19 were speculated to play the important roles in the salt tolerance of C. glauca induced by R. irregularis. Our research systematically revealed the effect of R. irregularis on the gene expression of C. glauca roots under salt stress, laying a theoretical foundation for the future use of AMF to enhance plant tolerance to salt stress.