JUAN CARLOS STOCKERT^1,2,*, ALFONSO BLÁZQUEZ-CASTRO³

BIOCELL, Vol.46, No.6, pp. 1391-1415, 2022, DOI:10.32604/biocell.2022.019493

Abstract

Melanins represent one of the most ancient and important group of natural macromolecular pigments. They have multiple biological roles in almost all organisms across the Phyla, examples being photoprotection, anti-oxidative action, radical scavenger activity, and heavy metal removal. From the biomedical point of view, melanocytes are involved in the origin of melanoma tumors, and the main therapeutic advances for their treatment have been revised in Part 1 of this review. The chemical structure of eumelanin is a biological concern of great importance, and therefore, exploring theoretical molecular models and synthesis mechanisms will be here described, as well as molecular orbital… More >

Aijia Zhang, Yingju Yang, Jing Liu^*, Junyan Ding

Energy Engineering, Vol.119, No.2, pp. 499-510, 2022, DOI:10.32604/ee.2022.015504

Abstract CuMn₂O₄ spinel has been regarded as a highly efficient sorbent for Hg⁰ capture from flue gas. The regenerability and recyclability of CuMn₂O₄ sorbent are mainly associated with the mercury speciation adsorbed on its surface. However, the effect mechanism of HCl on Hg⁰ transformation over CuMn₂O₄ sorbent is still elusive. Experiments were conducted to understand the effect of HCl on Hg⁰ transformation over CuMn₂O₄ sorbent. The results indicate that CuMn₂O₄ sorbent is a mesoporous material and possesses a good thermal stability. CuMn₂O₄ shows >95% Hg⁰ removal efficiency in a wide temperature window of 50–350°C. The favorable electron-transfer environment caused by the… More >

Lihua Zhu^1,*, Yu Wang¹, Zhiqiang Wu¹, Cheire Cheng²

Intelligent Automation & Soft Computing, Vol.33, No.1, pp. 291-303, 2022, DOI:10.32604/iasc.2022.024252

Abstract The rapid developments of artificial intelligence in the last decade are influencing aerospace engineering to a great extent and research in this context is proliferating. In this paper, the trajectory optimization of a three-stage launch vehicle in the powering phase subject to the sun-synchronous orbit is considered. To solve the optimal control problem, the Gauss pseudo-spectral method (GPM) is used to transform the optimization model to a nonlinear programming (NLP) problem and sequential quadratic programming is applied to find the optimal solution. However, the sensitivity of the initial guess may cost the solver significant time to do the Newton iteration… More >

Ismail Hossain¹, Md Samsuzzaman², Mohd Hafiz Baharuddin^3,*, Norsuzlin Binti Mohd Sahar¹, Mandeep Singh Jit Singh¹, Mohammad Tariqul Islam³

CMC-Computers, Materials & Continua, Vol.71, No.2, pp. 3905-3920, 2022, DOI:10.32604/cmc.2022.022027

Abstract This study presents an Epsilon Mu near-zero (EMNZ) nanostructured metamaterial absorber (NMMA) for visible regime applications. The resonator and dielectric layers are made of tungsten (W) and quartz (fused), where the working band is expanded by changing the resonator layer's design. Due to perfect impedance matching with plasmonic resonance characteristics, the proposed NMMA structure is achieved an excellent absorption of 99.99% at 571 THz, 99.50% at 488.26 THz, and 99.32% at 598 THz frequencies. The absorption mechanism is demonstrated by the theory of impedance, electric field, and power loss density distributions, respectively. The geometric parameters are explored and analyzed to… More >

Jin Yang^1,2, Wen Liang¹, Xingyang He^1,2,*, Ying Su^1,2, Fulong Wang¹, Tie Wang¹, Jianxiang Huang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 15-27, 2022, DOI:10.32604/fdmp.2022.018135

Abstract A solution polymerization method has been used to synthesize a polyacrylic-type superabsorbent polymer (SAP). The influence of various influential factors, such as the temperature, neutralization degree, cross-linking agent, and initiator, on the water absorption capacity of SAP has been investigated. The results show that the absorption can display a non-monotonic behavior depending on the synthesis conditions. The absorption can also change according to the pH, ion types and ion concentration. As the pH value increases, the water absorption capacity decreases significantly. It also decreases if the Na⁺ concentration becomes higher and becomes particularly low in solutions containing Mg²⁺. With the… More >

Ismail Hossain¹, Md Samsuzzaman², Ahasanul Hoque³, Mohd Hafiz Baharuddin³, Norsuzlin Binti Mohd Sahar¹, Mohammad Tariqul Islam^3,*

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 993-1009, 2022, DOI:10.32604/cmc.2022.021435

Abstract Broadband response metamaterial absorber (MMA) remains a challenge among researchers. A nanostructured new zero-indexed metamaterial (ZIM) absorber is presented in this study, constructed with a hexagonal shape resonator for optical region applications. The design consists of a resonator and dielectric layers made with tungsten and quartz (Fused). The proposed absorbent exhibits average absorption of more than 0.8972 (89.72%) within the visible wavelength of 450–600 nm and nearly perfect absorption of 0.99 (99%) at 461.61 nm. Based on computational analysis, the proposed absorber can be characterized as ZIM. The developments of ZIM absorbers have demonstrated plasmonic resonance characteristics and a perfect… More >

KATARINA BARALIć^1,*, KATARINA ŽIVANčEVIć¹, DRAGICA BoŽIĆ¹, DANYEL JENNEN², ALEKSANDRA BUHA DJORDJEVIC¹, EVICA ANTONIJEVIć MILJAKOVIć¹, DANIJELA ĐUKIć-ĆOSIć¹

BIOCELL, Vol.46, No.2, pp. 519-533, 2022, DOI:10.32604/biocell.2022.018271

Abstract This in silico toxicogenomic study aims to explore the relationship between phthalates and bisphenol A (BPA) co-exposure and obesity, as well as its comorbid conditions, in order to construct a possible set of genomic biomarkers. The Comparative Toxicogenomics Database (CTD; http://ctd.mdibl.org) was used as the main data mining tool, along with GeneMania (https://genemania.org), ToppGene Suite (https://toppgene.cchmc.org) and DisGeNET (http://www.disgenet.org). Among the phthalates, bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) were chosen as the most frequently curated phthalates in CTD, which also share similar mechanisms of toxicity. DEHP, DBP and BPA interacted with 84, 90 and 194 obesity-related genes/proteins, involved in… More >

FRANCISCO J. CORPAS^*, SALVADOR GONZÁLEZ-GORDO, MARTA RODRÍGUEZ-RUIZ, MARÍA A. MUÑOZ-VARGAS, JOSÉ M. PALMA

BIOCELL, Vol.46, No.1, pp. 1-5, 2022, DOI:10.32604/biocell.2021.017300

Abstract Nitric oxide (NO) and hydrogen sulfide (H₂S) are two molecules that share signaling properties in plant and animal cells. NO and H₂S originate two families of derived molecules designated reactive nitrogen and sulfur species (RNS and RSS, respectively). These molecules are responsible for certain protein regulatory processes through posttranslational modifications (PTMs), being the most remarkable S-nitrosation and persulfidation, which affect the thiol group of cysteine residues. NO and H₂S can also exert regulatory functions due to their interaction through the iron present in proteins that contain heme groups or iron-sulfur clusters, as reported mainly in animal cells. However, the available… More >

Tamara A. Al-Shurbaji¹, Khalid A. AlKaabneh², Issam Alhadid^3,*, Ra’ed Masa’deh⁴

Intelligent Automation & Soft Computing, Vol.31, No.2, pp. 971-985, 2022, DOI:10.32604/iasc.2022.019654

Abstract Scale-Invariant Feature Transform is an image matching algorithm used to match objects of two images by extracting the feature points of target objects in each image. Scale-Invariant Feature Transform suffers from long processing time due to embedded calculations which reduces the overall speed of the technique. This research aims to enhance SIFT processing time by imbedding Chamfer Distance Algorithm to find the distance between image descriptors instead of using Euclidian Distance Algorithm used in SIFT. Chamfer Distance Algorithm requires less computational time than Euclidian Distance Algorithm because it selects the shortest path between any two points when the distance is… More >

Hongmei Zhang^1,*, Quancheng Zhou²

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1101-1111, 2021, DOI:10.32604/fdmp.2021.017202

Abstract Huge amounts of Xanthoceras sorbifolia husks (XSH) are typically discarded after oil extraction. Since pyrolysis represents a promising solution to harness the bio-energy of XSH, in the present work the pyrolytic and kinetic characteristics of XSH and related crude cellulose extract (CCE) were studied considering different rates of heating (10, 30 and 50°C min⁻¹). The pyrolysis activation energy, pre-exponential factors and mechanism function were computed using different models namely Popescu, FWO (Flynn-Wall-Ozawa) and KAS (Kissinger-Akahira-Sunose). The pyrolysis process was articulated into three stages: dehydration (Stage I), primary devolatilization (Stage II), residual decomposition (Stage III). Marked variations in the average activation… More >