bluuebunny/crossref_metadata_2025 huggingface dataset:
Eco-Friendly NiO/Polydopamine Nanocomposite for Efficient Removal of Dyes from Wastewater
Authors: El-Ghobashy Marwa , Hashim Hisham , Darwish Moustafa , Khandaker Mayeen , Sulieman Abdelmoneim , Tamam Nissren , Trukhanov Sergei , Trukhanov Alex , Salem Mohamed
Published: March 2022

The rapid development of industries discharges huge amounts of wastewater that contain surface water. For this reason, we used NiO/polydopamine (NiO/PDA) nanocomposite as an efficient material for the removal of Methyl violet 2B from water. It was synthesized and then characterized by Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) analysis, Transmission Electron Microscopy (TEM), and Brunauer–Emmett–Teller (BET). The EDX analysis confirmed the presence of O, Ni, N, and C. The composite has an average particle size of 18 nm. Its surface area is 110.591 m2/g. It was found that the efficiency of dye removal by adsorption on NiO/PDA exceeded that of bare NiO. The adsorption capacity of NiO and NiO/PDA are 126 and 284 mg/g, respectively. The effects of adsorbent dose, dye concentration, and pH on the removal efficiency were examined. The efficiency increased with increasing the adsorbent dose and pH, but dropped from 85 to 73% within 30 min as the initial dye concentration was increased from 0.984 to 4.92 mg/L. Such a drop in the removal efficiency is due to the blocking of the surface-active sites of NiO/PDA, with the high population of dye molecules derived from the continuous increase in dye concentration. The adsorption results of the dye fitted well with the pseudo-second-order kinetics and Langmuir isotherm. The reusability data showed that NiO/PDA was stable across three adsorption–regeneration cycles, thus it can be considered a good recyclable and efficient adsorbent. Because of these results, it can be considered that this method can be applied for the treatment of wastewater.
Children Receiving a Nutrition and High-Quality Early Childhood Education Intervention Are Associated with Greater Math and Fluid Intelligence Scores: The Guatemala City Municipal Nurseries
Authors: Palacios Ana M. , Villanueva Lisa M. , Flynn Matthew B. , Parker Erik , Dickinson Stephanie , Bland Helen W. , Reinhart Greg A.
Published: March 2022

Background: About 47% of children < 5 years of age are stunted in Guatemala. In this study, the investigators aimed to compare growth and cognitive outcomes between children in second grade that attended five Guatemala City Municipal Nurseries (GCMN) vs. same sex, grade, and age-matched children. Methods: A cross-sectional design nested in a retrospective cohort was implemented between 2015 and 2019. Children that attended the GCMN and matched controls completed a math test and validated receptive language and fluid intelligence tests. The primary caregivers completed a sociodemographic survey. General and generalized linear mixed effect models were used to compare children that attended the GCMN vs. controls. The models were adjusted by maternal education, sex, asset score, and other relevant covariates. Results: Children that attended the GCMN exhibited greater math and fluid intelligence scores relative to the controls in the adjusted models (ß = 6.48; 95% CI (2.35–10.61)) and (ß = 1.20; 95% CI (0.12–2.29)), respectively. Lower odds of stunting were significant for children who went to any early childcare institution (AOR = 0.28; 95% CI (0.09–0.89)). Conclusions: The importance of integrating nutrition and high-quality early childhood education interventions in cognitive and growth outcomes is highlighted in this study. The GCMN model may be a scalable model in similar low-resource settings.
Fitness, Food, and Biomarkers: Characterizing Body Composition in 19,634 Early Adolescents
Authors: Rodriguez Alina , Korzeniowska Katarzyna , Szarejko Kamila , Borowski Hubert , Brzeziński Michał , Myśliwiec Małgorzata , Czupryniak Leszek , Berggren Per-Olof , Radziwiłł Marcin , Soszyński Piotr
Published: March 2022

Adolescent obesity persists as a major concern, especially in Central and Eastern Europe, yet evidence gaps exist regarding the pivotal early adolescent years. Our objective was to provide a comprehensive picture using a holistic approach of measured anthropometry in early adolescence, including body composition, cardiorespiratory fitness (CRF), and reported lifestyle characteristics. We aimed to elucidate potential sex/gender differences throughout and associations to biomarkers of disease risk for obese adolescents. Methods: Trained nurses measured 19,634 early adolescents (12–14-year-olds), we collected parental reports, and, for obese adolescents, fasting blood samples in four major Polish cities using a cross-sectional developmental design. Results: 24.7% boys and 18.6% girls were overweight/obese, and 2886 had BMI ≥ 90th percentile. With increasing age, there was greater risk of obesity among boys (p for trend = 0.001) and a decreasing risk of thinness for girls (p for trend = 0.01). Contrary to debate, we found BMI (continuous) was a useful indicator of measured fat mass (FM). There were 38.6% with CRF in the range of poor/very poor and was accounted for primarily by FM in boys, rather than BMI, and systolic blood pressure in girls. Boys, in comparison to girls, engaged more in sports (t = 127.26, p < 0.0001) and consumed more fast food (t = 188.57, p < 0.0001) and sugar-sweetened beverages (167.46, p < 0.0001). Uric acid, a potential marker for prediabetes, was strongly related to BMI in the obese subsample for both boys and girls. Obese girls showed signs of undernutrition. Conclusion: these findings show that overweight/obesity is by far a larger public health problem than thinness in early adolescence and is characterized differentially by sex/gender. Moreover, poor CRF in this age, which may contribute to life course obesity and disease, highlights the need for integrated and personalized intervention strategies taking sex/gender into account.
Health Benefits, Pharmacological Effects, Molecular Mechanisms, and Therapeutic Potential of α-Bisabolol
Authors: Eddin Lujain Bader , Jha Niraj Kumar , Goyal Sameer N. , Agrawal Yogeeta O. , Subramanya Sandeep B. , Bastaki Salim M. A. , Ojha Shreesh
Published: March 2022

α-Bisabolol is one of the important monocyclic sesquiterpenes, derived naturally from essential oils of many edible and ornamental plants. It was first obtained from Matricaria chamomilla, commonly known as chamomile or German chamomile. The available literature indicates that this plant along with other α-Bisabolol containing plants is popularly used in traditional medicine for potential health benefits and general wellbeing. Nutritional studies are indicative of the health benefits of α-Bisabolol. Numerous experimental studies demonstrated pharmacological properties of α-Bisabolol including anticancer, antinociceptive, neuroprotective, cardioprotective, and antimicrobial. This review aims to collectively present different pharmacological activities based on both in vitro and in vivo studies. In the present review using synoptic tables and figures, we comprehensively present that α-Bisabolol possesses therapeutic and protective activities, therefore, it can be used for potential health benefits based on pharmacological effects, underlying molecular mechanism, and favorable pharmaceutical properties. Based on the studies mostly performed on cell lines or animal models, it is evident that α-Bisabolol may be a promising nutraceutical and phytomedicine to target aberrant biological mechanisms which result in altered physiological processes and various ailments. Given the polypharmacological effects and pleiotropic properties, along with favorable pharmacokinetics, and dietary availability and safety, α-Bisabolol can be used as a dietary agent, nutraceutical or phytopharmaceutical agent or as an adjuvant with currently available modern medicines. The regulatory approval of this molecule for use as food additives, and in cosmetics and fragrance industry is also supportive of its human usage. Moreover, further studies are necessary to address pharmaceutical, pharmacological, and toxicological aspects before clinical or nutritional usage in humans. The biological actions and health benefits open opportunities for pharmaceutical development with pharmacological basis of its use in future therapeutics.
Diet, Fecal Microbiome, and Trimethylamine N-Oxide in a Cohort of Metabolically Healthy United States Adults
Authors: James Kristen L. , Gertz Erik R. , Cervantes Eduardo , Bonnel Ellen L. , Stephensen Charles B. , Kable Mary E. , Bennett Brian J.
Published: March 2022

TMAO is elevated in individuals with cardiometabolic diseases, but it is unknown whether the metabolite is a biomarker of concern in healthy individuals. We conducted a cross-sectional study in metabolically healthy adults aged 18–66 years with BMI 18–44 kg/m2 and assessed the relationship between TMAO and diet, the fecal microbiome, and cardiometabolic risk factors. TMAO was measured in fasted plasma samples by liquid chromatography mass spectrometry. The fecal microbiome was assessed by 16S ribosomal RNA sequencing and recent food intake was captured by multiple ASA24 dietary recalls. Endothelial function was assessed via EndoPAT. Descriptive statistics were computed by fasting plasma TMAO tertiles and evaluated by ANOVA and Tukey’s post-hoc test. Multiple linear regression was used to assess the relationship between plasma TMAO and dietary food intake and metabolic health parameters. TMAO concentrations were not associated with average intake of animal protein foods, fruits, vegetables, dairy, or grains. TMAO was related to the fecal microbiome and the genera Butyribrio, Roseburia, Coprobaciullus, and Catenibacterium were enriched in individuals in the lowest versus the highest TMAO tertile. TMAO was positively associated with α-diversity and compositional differences were identified between groups. TMAO was not associated with classic cardiovascular risk factors in the healthy cohort. Similarly, endothelial function was not related to fasting TMAO, whereas the inflammatory marker TNF-α was significantly associated. Fasting plasma TMAO may not be a metabolite of concern in generally healthy adults unmedicated for chronic disease. Prospective studies in healthy individuals are necessary.
Fluid and Salt Balance and the Role of Nutrition in Heart Failure
Authors: Chrysohoou Christina , Mantzouranis Emmanouil , Dimitroglou Yannis , Mavroudis Andreas , Tsioufis Kostas
Published: March 2022

The main challenges in heart failure (HF) treatment are to manage patients with refractory acute decompensated HF and to stabilize the clinical status of a patient with chronic heart failure. Beyond the use of medications targeted in the inhibition of the neurohormonal system, the balance of salt and fluid plays an important role in the maintenance of clinical compensation in respect of renal function. In the case of heart failure, a debate of opinion exists on salt restriction. Restricted dietary sodium might lead to worse outcomes in heart failure patients due to the activation of the neurohormonal system and malnutrition. On the contrary, positive sodium balance is the primary driver of water retention and, ultimately, volume overload in acute HF. Some recent studies reported associations of decreased salt consumption with higher readmission rates and increased mortality. Thus, the usefulness of salt restriction in heart failure management remains debated. The use of individualized nutritional support, compared with standard hospital food, was effective in reducing these risks, particularly in the group of patients at high nutritional risk.
Obesity and Leptin Resistance in the Regulation of the Type I Interferon Early Response and the Increased Risk for Severe COVID-19
Authors: Muskiet Frits , Carrera-Bastos Pedro , Pruimboom Leo , Lucia Alejandro , Furman David
Published: March 2022

Obesity, and obesity-associated conditions such as hypertension, chronic kidney disease, type 2 diabetes, and cardiovascular disease, are important risk factors for severe Coronavirus disease-2019 (COVID-19). The common denominator is metaflammation, a portmanteau of metabolism and inflammation, which is characterized by chronically elevated levels of leptin and pro-inflammatory cytokines. These induce the “Suppressor Of Cytokine Signaling 1 and 3” (SOCS1/3), which deactivates the leptin receptor and also other SOCS1/3 sensitive cytokine receptors in immune cells, impairing the type I and III interferon early responses. By also upregulating SOCS1/3, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 adds a significant boost to this. The ensuing consequence is a delayed but over-reactive immune response, characterized by high-grade inflammation (e.g., cytokine storm), endothelial damage, and hypercoagulation, thus leading to severe COVID-19. Superimposing an acute disturbance, such as a SARS-CoV-2 infection, on metaflammation severely tests resilience. In the long run, metaflammation causes the “typical western” conditions associated with metabolic syndrome. Severe COVID-19 and other serious infectious diseases can be added to the list of its short-term consequences. Therefore, preventive measures should include not only vaccination and the well-established actions intended to avoid infection, but also dietary and lifestyle interventions aimed at improving body composition and preventing or reversing metaflammation.
Non-Pharmacological Treatments for Insulin Resistance: Effective Intervention of Plant-Based Diets—A Critical Review
Authors: Banaszak Michalina , Górna Ilona , Przysławski Juliusz
Published: March 2022

Plant-based diets are becoming increasingly popular. Vegetarian diets are better for the environment and exhibit health benefits. A correctly balanced plant-based diet is appropriate at every stage of life. Compared to omnivores, vegetarians consume more fruits and vegetables, more fibre, vitamins C and E, magnesium and less saturated fats. In general, they have better nutrition knowledge, and they are slimmer, healthier and live longer than omnivores. It also seems that following a plant-based diet prevents the onset of chronic diseases such as cardiovascular diseases, hypertension, type 2 diabetes, obesity and some cancers. Food intake has a key influence on insulin resistance. Consumption of calorie-rich and highly processed foods, meats and sweetened beverages is a characteristic element of Western diets. They promote and elevate insulin resistance and type 2 diabetes. In contrast, intake of pulses and exclusion of meats as well as animal products bring significant benefits to vegetarian diets. According to studies, vegetarians and vegans have better blood parameters, including better glucose, insulin, total cholesterol, and LDL cholesterol levels. Their homeostatic model assessment for insulin resistance (HOMA-IR) test results are also better. More plant-based foods and fewer animal foods in a diet result in lower insulin resistance and a lower risk of prediabetes and type 2 diabetes. The aim of the study was to investigate the effect of plant-based diets on insulin resistance. In this review, we focused on presenting the positive effects of vegetarian and vegan diets on insulin resistance while showing possible clinical applications of plant-based diets in the treatment and prevention of modern-age diseases. Current and reliable publications meeting the requirements of Evidence-Based Medicine (EBM) were taken into account in this review.
History of Slimming Diets up to the Late 1950s
Authors: Zarzo Inmaculada , Boselli Pietro Marco , Soriano Jose M.
Published: March 2022

Nowadays, obesity is a pandemic, and some people seek slimming diets to guarantee their health and quality of life. However, the cult of the healthy body has been an ongoing concern since the beginning of time. Irrespective of the century to which they belong, these cults reflect no empirical knowledge about physiology, nutrients or kilocalories, with some of them being quantitative diets in contrast to qualitative diets, or even simple food recommendations. On the other hand, some of these treatments might have led to the death of a patient, meaning that it is important for people seeking to lose weight to be followed by a nutrition professional until the individual reaches a desirable body weight. In this article, we highlight that each century and each decade have devised different treatments with the aim of improving health, but it will be science and history that will judge whether the results of these treatments have been adequate.
5-Aryl-1,3,4-oxadiazol-2-amines Decorated with Long Alkyl and Their Analogues: Synthesis, Acetyl- and Butyrylcholinesterase Inhibition and Docking Study
Authors: Pflégr Václav , Štěpánková Šárka , Svrčková Katarína , Švarcová Markéta , Vinšová Jarmila , Krátký Martin
Published: March 2022

2,5-Disubstituted 1,3,4-oxadiazoles are privileged versatile scaffolds in medicinal chemistry that have exhibited diverse biological activities. Acetyl- (AChE) and butyrylcholinesterase (BChE) inhibitors are used, e.g., to treat dementias and myasthenia gravis. 5-Aryl-1,3,4-oxadiazoles decorated with dodecyl linked via nitrogen, sulfur or directly to this heterocycle have been designed as potential inhibitors of AChE and BChE. They were prepared from commercially available or in-house prepared hydrazides by reaction with dodecyl isocyanate to form hydrazine-1-carboxamides 2 (yields 67–98%) followed by cyclization using p-toluenesulfonyl chloride and triethylamine in 41–100% yields. Thiadiazole isostere was also synthesized. The derivatives were screened for inhibition of AChE and BChE using Ellman’s spectrophotometric method. The compounds showed a moderate dual inhibition with IC50 values of 12.8–99.2 for AChE and from 53.1 µM for BChE. All the heterocycles were more efficient inhibitors of AChE. The most potent inhibitor, N-dodecyl-5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine 3t, was subjected to advanced reversibility and type of inhibition evaluation. Structure–activity relationships were identified. Many oxadiazoles showed lower IC50 values against AChE than established drug rivastigmine. According to molecular docking, the compounds interact non-covalently with AChE and BChE and block entry into enzyme gorge and catalytic site, respectively.
Allogenic Amniotic Tissue for Treatment of Knee and Hip Osteoarthritis
Authors: Gupta Ashim
Published: March 2022

Osteoarthritis (OA) impacts millions of people and places a high burden on healthcare systems in the United States. Current treatment modalities have limitations and do not address underlying pathology. Lately, there has been an immense growth in the use of biologics, including perinatal allogenic tissues for orthopedic regenerative medicine applications. Amniotic tissue is an exciting new alternative for such applications. Despite several published studies that reported its use for treatment of ophthalmic conditions and complex wounds, there are limited clinical studies evaluating its safety and efficacy in treating patients suffering with knee or hip OA. In this manuscript, I focused on three prospective clinical studies which evaluated the safety and efficacy of amniotic tissue in patients suffering with moderate knee or hip OA. The results from these studies presented the scientific community with much needed, well-executed, and prospective clinical trials. Though these trials demonstrated that administration of amniotic tissue in knee or hip joint is safe and potentially effective, more multi-center, prospective, double-blinded, randomized controlled trials are warranted to further establish the efficacy of amniotic tissue to mitigate symptoms of knee and hip OA to ultimately justify its clinical use.
The Effects of Various Food Products on Bisphosphonate’s Availability
Authors: Zielińska Monika , Garbacz Grzegorz , Sczodrok Jaroslaw , Voelkel Adam
Published: March 2022

The bioavailability of orally administered bisphosphonates is very low (<1%) due to their short absorption window in the proximal duodenum and high affinity for food. Food ingredients are able to bind the drug, but the presence of food extends the residence time of bisphosphonates in the absorption window. Therefore, the main goal of this study is to select a group of food products that are characterized by low binding affinity to bisphosphonates and thus will not reduce their availability upon concomitant administration. For this purpose, a combination of three methods was applied: (1) evaluation of sorption capacity for rows of digested food samples in a simulated intestinal environment; (2) evaluation of drug availability in simulated chyme; and (3) evaluation of drug availability using a simulating needle device. The results indicate that food products such as egg white and white bread are most suitable for consumption during oral bisphosphonate intake.
Backpropagation of Spirit: Hegelian Recollection and Human-A.I. Abductive Communities
Authors: Gangle Rocco
Published: March 2022

This article examines types of abductive inference in Hegelian philosophy and machine learning from a formal comparative perspective and argues that Robert Brandom’s recent reconstruction of the logic of recollection in Hegel’s Phenomenology of Spirit may be fruitful for anticipating modes of collaborative abductive inference in human/A.I. interactions. Firstly, the argument consists of showing how Brandom’s reading of Hegelian recollection may be understood as a specific type of abductive inference, one in which the past interpretive failures and errors of a community are explained hypothetically by way of the construction of a narrative that rehabilitates those very errors as means for the ongoing successful development of the community, as in Brandom’s privileged jurisprudential example of Anglo-American case law. Next, this Hegelian abductive dynamic is contrasted with the error-reducing backpropagation algorithms characterizing many current versions of machine learning, which can be understood to perform abductions in a certain sense for various problems but not (yet) in the full self-constituting communitarian mode of creative recollection canvassed by Brandom. Finally, it is shown how the two modes of “error correction” may possibly coordinate successfully on certain types of abductive inference problems that are neither fully recollective in the Hegelian sense nor algorithmically optimizable.
Analysis and Simulation of the Optical Properties of a Quantum Dot on a Graphene Nanoribbon System
Authors: Armaghani Sahar , Rostami Ali , Mirtaheri Peyman
Published: March 2022

In this work, we theoretically study the optical properties of a graphene nanoribbon with a quantum dot (QD) on it. The system consists of a graphene nanoribbon with dimensions of 400 × 3100 (nm2) and a quantum dot with a nanoscale radius. The quantum dot is symmetrically located at the center of the graphene nanoribbon to simplify the mathematical model. To calculate the optical properties (susceptibility) of the system, a broadband electromagnetic wave (0.5–2.5 μm) is applied to the structure to model dipole-dipole interaction. Considering the input field and calculating the total induced polarization, the optical susceptibility of the system is calculated. The applied electromagnetic field excites the surface plasmon on the graphene nanoribbon and the excitons of QDs. The induced dipoles in the graphene nanoribbon and the QD will interact with each other. We show that the parameters of both materials strongly influence dipole-dipole interaction. In particular, the effect of QDs (location on graphene and radius) on the optical properties of the considered system was studied. The obtained results can be used to introduce periodic optical structures in nanoscale by inserting QDs in a periodic array on graphene nanoribbon. Additionally, applications such as reflectors, couplers, and wavelength filters can be designed. Considering the presented theoretical framework, we can describe all the optoelectronic and optomechanical applications of complex nanoscale graphene and QD systems.
Improved Thermal and Electromagnetic Shielding of PEEK Composites by Hydroxylating PEK-C Grafted MWCNTs
Authors: Wen Fengyu , Li Shu , Chen Rui , He Yashu , Li Lei , Cheng Lin , Ma Jierun , Mu Jianxin
Published: March 2022

With the rapid rise of new technologies such as 5G and artificial intelligence, electronic products are becoming smaller and higher power, and there is an increasing demand for electromagnetic interference shielding and thermal conductivity of electronic devices. In this work, hydroxyphenolphthalein type polyetherketone grafted carboxy carbon nanotube (PEK-C-OH-g-MWCNTs-COOH) composites were prepared by esterification reaction. The composites exhibited good thermal conductivity, and compared with (MWCNTs-COOH/PEEK) with randomly distributed fillers, (PEK-C-OH-g-MWCNTs-COOH) composites showed a significant advantage, with the same carbon nanotube content, the thermal conductivity of PEK-C-OH-g-MWCNTs-COOH/PEEK (30 wt%) was 0. 71 W/(m-K), which was 206% higher than that of PEEK and 0.52 W/(m-K) higher than that of MWCNTs-COOH/PEEK (26.1 wt%). In addition, the PEK-C-OH-g-MWCNTs-COOH) composite exhibited excellent electrical conductivity and electromagnetic shielding (SE). The SE of 30 wt% PEK-C-OH-g-MWCNTs-COOH/PEEK is higher than the commercially used standard whose value is 22.9 dB (8.2 GHz). Thus, this work provides ideas for the development of thermally conductive functionalized composites.
Surface Response Analysis for the Optimization of Mechanical and Thermal Properties of Polypropylene Composite Drawn Fibers with Talc and Carbon Nanotubes
Authors: Leontiadis Konstantinos , Tsioptsias Costas , Messaritakis Stavros , Terzaki Aikaterini , Xidas Panagiotis , Mystikos Kyriakos , Tzimpilis Evangelos , Tsivintzelis Ioannis
Published: March 2022

A large portion of the produced Polypropylene (PP) is used in the form of fibers. In this industrially oriented study, the development of composite PP drawn fibers was investigated. Two types of fillers were used (ultra-fine talc and single-wall carbon nanotubes). Optimization of the thermal and mechanical properties of the produced composite drawn fibers was performed, based on the Box-Behnken design of experiments method (surface response analysis). The effect of additives, other than the filler, but typical in industrial applications, such as an antioxidant and a common compatibilizer, was investigated. The drawing ratio, the filler, and the compatibilizer or the antioxidant content were selected as design variables, whereas the tensile strength and the onset decomposition temperature were set as response variables. Fibers with very high tensile strength (up to 806 MPa) were obtained. The results revealed that the maximization of both the tensile strength and the thermal stability was not feasible for composites with talc due to multiple interactions among the used additives (antioxidant, compatibilizer, and filler). Additionally, it was found that the addition of talc in the studied particle size improved the mechanical strength of fibers only if low drawing ratios were used. On the other hand, the optimization targeting maximization of both tensile strength and thermal stability was feasible in the case of SWCNT composite fibers. It was found that the addition of carbon nanotubes improved the tensile strength; however, such improvement was rather small compared with the tremendous increase of tensile strength due to drawing.
Facile Preparation of Chitosan-Based Composite Film with Good Mechanical Strength and Flame Retardancy
Authors: Chen Jirui , Huang Wentao , Chen Yifan , Zhou Zenan , Liu Huan , Zhang Wenbiao , Huang Jingda
Published: March 2022

To improve on the poor strength and flame retardancy of a chitosan (CS)-based functional film, cellulose nanofiber (CNF) was taken as the reinforced material and both ammonium polyphosphate (APP) and branched polyethyleneimine (BPEI) as the flame-retardant additives in the CS matrix to prepare the CS/CNF/APP/BPEI composite film by simple drying. The resulting composite film showed good mechanical strength, with a tensile strength reaching 71.84 Mpa due to the high flexibility of CNF and the combination of CS, CNF and BPEI through strong hydrogen bonding interactions. The flame retardant-performance of the composite film greatly enhanced the limit oxygen index (LOI), up to 32.7% from 27.6% for the pure film, and the PHRR intensity decreased to 28.87 W/g from 39.38% in the micro-scale combustion calorimetry (MCC) test due to the ability of BPEI to stimulate the decomposition of APP, releasing non-flammable gases such as CO2, N2, NH3, etc., and forming a protective phosphating layer to block the entry of O2. Based on the good flame retardancy, mechanical strength and transparency, the CS/CNF/APP/BPEI composite film has a great potential for future applications.
Enhanced Toughness and Sound Absorption Performance of Bio-Aerogel via Incorporation of Elastomer
Authors: Shen Junshi , Hu Ruofei , Jiang Xueliang , You Feng , Yao Chu , Yang Huan , Yu Peng
Published: March 2022

In this study, Arabic gum/ carboxylic butadiene-acrylonitrite latex aerogels (AG/XNBRL) hybrid aerogel was successfully prepared by a green method, i.e., the combination of latex compounding and vacuum freeze-drying process. After that, the obtained composites were subjected to a high temperature treatment to crosslink the rubber phase. It was found that the AG in the AG/XNBRL hybrid aerogel could act as a framework to improve the dimensional stability of the aerogel, while the XNBRL phase could significantly improve the mechanical flexibility of the ensuing composite. Compared to the AG aerogel which is highly brittle in nature, the AG/XNBRL hybrid aerogel not only exhibits significantly enhanced toughness, but also shows improved thermal stability and sound absorption performances; for instance, the half weight loss (50%) temperature and average sound adsorption coefficient for aerogel containing 30 wt% XNBRL is 344 °C and 0.585, respectively, which are superior to those of neat AG aerogel. Overall, this work provides novel inspiration to prepare the mechanical robust bio-based aerogel for the sound absorption application.
Direct Bragg Grating Inscription in Single Mode Step-Index TOPAS/ZEONEX Polymer Optical Fiber Using 520 nm Femtosecond Pulses
Authors: Hu Xuehao , Chen Yuhang , Gao Shixin , Min Rui , Woyessa Getinet , Bang Ole , Qu Hang , Wang Heng , Caucheteur Christophe
Published: March 2022

We experimentally report fiber Bragg gratings (FBGs) in a single mode step-index polymer optical fiber (POF) with a core made of TOPAS and cladding made of ZEONEX using 520 nm femtosecond pulses and a point-by-point (PbP) inscription method. With different pulse energies between 9.7 nJ and 11.2 nJ, 12 FBGs are distributed along the cores of two pieces of POFs with negative averaged effective index change up to ~6 × 10−4 in the TOPAS. For POF 1 with FBGs 1–6, the highest reflectivity 45.1% is obtained with a pulse energy of 10.6 nJ. After inscription, good grating stability is reported. Thanks to the post-annealing at 125 °C for 24 h, after cooling the grating reflectivity increases by ~10%. For POF 2 with FBGs 7–12, similar FBG data are obtained showing good reproducibility. Then, the FBGs are annealed at 125 °C for 78 h, and the average reflectivity of the FBGs during the annealing process increases by ~50% compared to that before the annealing, which could be potentially applied to humidity insensitive high temperature measurement.
Effects of Mechanical Deformation on the Opto-Electronic Responses, Reactivity, and Performance of Conjugated Polymers: A DFT Study
Authors: Cachaneski-Lopes João P. , Batagin-Neto Augusto
Published: March 2022

The development of polymers for optoelectronic applications is an important research area; however, a deeper understanding of the effects induced by mechanical deformations on their intrinsic properties is needed to expand their applicability and improve their durability. Despite the number of recent studies on the mechanochemistry of organic materials, the basic knowledge and applicability of such concepts in these materials are far from those for their inorganic counterparts. To bring light to this, here we employ molecular modeling techniques to evaluate the effects of mechanical deformations on the structural, optoelectronic, and reactivity properties of traditional semiconducting polymers, such as polyaniline (PANI), polythiophene (PT), poly (p-phenylene vinylene) (PPV), and polypyrrole (PPy). For this purpose, density functional theory (DFT)-based calculations were conducted for the distinct systems at varied stretching levels in order to identify the influence of structural deformations on the electronic structure of the systems. In general, it is noticed that the elongation process leads to an increase in electronic gaps, hypsochromic effects in the optical absorption spectrum, and small changes in local reactivities. Such changes can influence the performance of polymer-based devices, allowing us to establish significant structure deformation response relationships.
Evaluating Non-Conventional Chitosan Sources for Controlled Release of Risperidone
Authors: Garcinuño Sara , Aranaz Inmaculada , Civera Concepción , Arias Concepción , Acosta Niuris
Published: March 2022

In this work, two chitosan samples from cuttlebone and squid pen are produced and characterized. We studied the formation of thermoresponsive hydrogels with β-glycerol phosphate and found proper formulations that form the hydrogels at 37 °C. Gel formation depended on the chitosan source being possible to produce the thermoresponsive hydrogels at chitosan concentration of 1% with cuttlebone chitosan but 1.5% was needed for squid pen. For the first time, these non-commercial chitosan sources have been used in combination with β-glycerol phosphate to prepare risperidone formulations for controlled drug delivery. Three types of formulations for risperidone-controlled release have been developed, in-situ gelling formulations, hydrogels and xerogels. The release profiles show that in-situ gelling formulations and particularly hydrogels allow an extended control release of risperidone while xerogels are not appropriate formulations for this end since risperidone was completely released in 48 h.
Successful Manufacturing Protocols of N-Rich Carbon Electrodes Ensuring High ORR Activity: A Review
Authors: Skorupska Malgorzata , Ilnicka Anna , Lukaszewicz Jerzy P.
Published: March 2022

The exploration and development of different carbon nanomaterials happening over the past years have established carbon electrodes as an important electrocatalyst for oxygen reduction reaction. Metal-free catalysts are especially promising potential alternatives for replacing Pt-based catalysts. This article describes recent advances and challenges in the three main synthesis manners (i.e., pyrolysis, hydrothermal method, and chemical vapor deposition) as effective methods for the production of metal-free carbon-based catalysts. To improve the catalytic activity, heteroatom doping the structure of graphene, carbon nanotubes, porous carbons, and carbon nanofibers is important and makes them a prospective candidate for commercial applications. Special attention is paid to providing an overview on the recent major works about nitrogen-doped carbon electrodes with various concentrations and chemical environments of the heteroatom active sites. A detailed discussion and summary of catalytic properties in aqueous electrolytes is given for graphene and porous carbon-based catalysts in particular, including recent studies performed in the authors’ research group. Finally, we discuss pathways and development opportunities approaching the practical use of mainly graphene-based catalysts for metal–air batteries and fuel cells.
Advances on the Antioxidant Activity of a Phytocomplex Product Containing Berry Extracts from Romanian Spontaneous Flora
Authors: Moroșan Elena , Secăreanu Ana Andreea , Musuc Adina Magdalena , Mititelu Magdalena , Ioniță Ana Corina , Ozon Emma Adriana , Dărăban Adriana Maria , Karampelas Oana
Published: March 2022

The present study aimed to evaluate the antioxidant properties of a phytocomplex product obtained using 10% hydroalcoholic extractive solutions, in equal proportions, from Ribes nigrum, Rubus idaeus, Rubus fruticosus and Fragaria moschata fresh fruits harvested from the spontaneous flora of Romania. These plant products were recognized for their rich antioxidant content. The phytochemical profile was assessed using HPLC chromatography and UV-Vis spectrometry. The obtained results highlighted the presence of complex bioactive compounds with antioxidant actions, namely anthocyanins, proanthocyanins and vitamin C. The antioxidant actions of the hydroalcoholic extractive solutions and the phytocomplex product were evaluated using chemiluminescence, electrochemical and superoxide dismutase (SOD) methods. The experimental results showed evident antioxidant activity in both the hydroalcoholic extracts and the phytocomplex product.
Islamophobia in the West: A Critical Discourse Analysis of Imran Khan’s UNGA Speech
Authors: Javaid Meesam , Khan Mohsin Hassan , Kaur Surinderpal , Qazalbash Farwa
Published: March 2022

The tragic and horrendous attack on the World Trade Center also served to construct an unmistakable shape to Islamophobia in the West. It worked as fuel for the already-lit fire of Islamophobia and aggravated the situation with numerous indiscriminate attacks on Muslims. The situation worsened with George Bush’s unequivocal statement: “either you are with us or against us”. This was the call for a cultural war between the West and Muslims framed by the Us versus Them schemata. This research has analyzed the speech of Imran Khan which he delivered at the 74th session of the United Nations General Assembly, employing van Dijk’s Ideological Square Model with a specific focus on NVivo 12 Plus to inspect the magnitude of the impact of linguistic memorandums from authoritative institutes. The researchers have investigated the lexicalization of Khan’s speech to explore how he uses language to sketch the picture of the West as “them” parallel to “us”. His rhetoric is critically examined through the micro and macro-strategies of the Ideological Square Model. The findings reveal that instead of challenging and interrogating the Us versus Them schema that permeates Islamophobia, Khan himself uses the very same schema to show ideological differences between the West and Muslims.
Aga Khan IV and Contemporary Isma‘ili Identity: Pluralist Vision and Rooted Cosmopolitanism
Authors: Dewji Sahir
Published: March 2022

Cosmopolitan engagement and pluralism are consistent themes that run through the Isma‘ili community’s history and continue to be an integral characteristic of the community’s identity. The present Isma‘ili Imam, Karim Aga Khan IV, has been lauded as a champion of pluralism and recognized for his commitment to cosmopolitan ethics which feature prominently in his discourses to both Isma‘ili adherents and other communities. Although the Isma‘ilis have faced vilification and massacres in the course of history, this Muslim minority community has come to be recognized for its endeavors in the area of pluralism and bridge-building under the leadership of Aga Khan IV. The Imam offers religious and worldly guidance from his residence in France, where he has established a Secretariat that includes a number of departments that steer the various communal (jama‘ati) institutions as well as his non-denominational Aga Khan Development Network (AKDN). This non-denominational organization established by Aga Khan IV has emerged as a world leading non-governmental organization providing a number of programs toward improving the quality of life of Muslims and others across the globe. Through his institutions, Aga Khan IV stresses the need for a healthy pluralism that is supported by dialogue and engagement with diversity. One such institution is the Global Centre for Pluralism based in Ottawa, Canada—an international research institution whose activities are underpinned by the Imam’s ethico-religious interpretation of the Islamic faith and commitment to civil society. Aga Khan IV’s discourse of pluralism and cosmopolitan ethics has placed his community at the forefront of engagement with an increasingly diverse world.
Visual Object Tracking for Unmanned Aerial Vehicles Based on the Template-Driven Siamese Network
Authors: Sun Lifan , Yang Zhe , Zhang Jinjin , Fu Zhumu , He Zishu
Published: March 2022

Visual object tracking for unmanned aerial vehicles (UAV) is widely used in many fields such as military reconnaissance, search and rescue work, film shooting, and so on. However, the performance of existing methods is still not very satisfactory due to some complex factors including viewpoint changing, background clutters and occlusion. The Siamese trackers, which offer a convenient way of formulating the visual tracking problem as a template matching process, have achieved success in recent visual tracking datasets. Unfortunately, these template match-based trackers cannot adapt well to frequent appearance change in UAV video datasets. To deal with this problem, this paper proposes a template-driven Siamese network (TDSiam), which consists of feature extraction subnetwork, feature fusion subnetwork and bounding box estimation subnetwork. Especially, a template library branch is proposed for the feature extraction subnetwork to adapt to the changeable appearance of the target. In addition, a feature aligned (FA) module is proposed as the core of feature fusion subnetwork, which can fuse information in the form of center alignment. More importantly, a method for occlusion detection is proposed to reduce the noise caused by occlusion. Experiments were conducted on two challenging benchmarks UAV123 and UAV20L, the results verified the more competitive performance of our proposed method compared to the existing algorithms.
Integrity Monitoring of PPP-RTK Positioning; Part II: LEO Augmentation
Authors: Wang Kan , El-Mowafy Ahmed , Wang Wei , Yang Long , Yang Xuhai
Published: March 2022

Low Earth orbit (LEO) satellites benefit future ground-based positioning with their high number, strong signal strength and high speed. The rapid geometry change with the LEO augmentation offers acceleration of the convergence of the precision point positioning (PPP) solution. This contribution discusses the influences of the LEO augmentation on the precise point positioning—real-time kinematic (PPP-RTK) positioning and its integrity monitoring. Using 1 Hz simulated data around Beijing for global positioning system (GPS)/Galileo/Beidou navigation satellite system (BDS)-3 and the tested LEO constellation with 150 satellites on L1/L5, it was found that the convergence of the formal horizontal precision can be significantly shortened in the ambiguity-float case, especially for the single-constellation scenarios with low precision of the interpolated ionospheric delays. The LEO augmentation also improves the efficiency of the user ambiguity resolution and the formal horizontal precision with the ambiguities fixed. Using the integrity monitoring (IM) procedure introduced in the first part of this series of papers, the ambiguity-float horizontal protection levels (HPLs) are sharply reduced in various tested scenarios, with an improvement of more than 60% from 5 to 30 min after the processing start. The ambiguity-fixed HPLs can generally be improved by 10% to 60% with the LEO augmentation, depending on the global navigation satellite system (GNSS) constellations used and the precision of the ionospheric interpolation.
Nowcasting System Based on Sky Camera Images to Predict the Solar Flux on the Receiver of a Concentrated Solar Plant
Authors: Alonso-Montesinos Joaquín , Monterreal Rafael , Fernandez-Reche Jesus , Ballestrín Jesús , López Gabriel , Polo Jesús , Barbero Francisco Javier , Marzo Aitor , Portillo Carlos , Batlles Francisco Javier
Published: March 2022

As part of the research for techniques to control the final energy reaching the receivers of central solar power plants, this work combines two contrasting methods in a novel way as a first step towards integrating such systems in solar plants. To determine the effective power reaching the receiver, the direct normal irradiance was predicted at ground level using a total sky camera, TSI-880 model. Subsequently, these DNI values were used as the inputs for a heliostat model (Fiat-Lux) to trace the sunlight’s path according to the mirror features. The predicted valuex of flux, obtained from these simulations, differ of less than 20% from the real values. This represents a significant advance in integrating different technologies to quantify the losses produced in the path from the heliostats to the central receiver, which are normally caused by the presence of atmospheric attenuation factors.
Modulation Mode Recognition Method of Non-Cooperative Underwater Acoustic Communication Signal Based on Spectral Peak Feature Extraction and Random Forest
Authors: Fang Tao , Wang Qian , Zhang Lanyue , Liu Songzuo
Published: March 2022

The modulation mode recognition of non-cooperative underwater acoustic (UWA) communication signal faces great challenges due to the influence of the UWA channel and the demand for efficient recognition. This work proposes a recognition method for UWA orthogonal frequency division multiplexing (OFDM), binary frequency shift keying (2FSK), four-frequency shift keying (4FSK), and eight-frequency shift keying (8FSK) by using spectral peak feature extraction combined with random forest (RF). First, a new spectral peak feature extraction method is proposed. In this method, pre-processing, waveform optimization, and feature extraction are used to ensure that the extracted feature maintains high robustness in the UWA channel. Then, we designed an RF classifier that can meet the demand for high-efficiency recognition and good performance. Finally, simulation and experimental results verified the feasibility of the recognition method.
Spaceborne GNSS Reflectometry
Authors: Yu Kegen , Han Shuai , Bu Jinwei , An Yuhang , Zhou Zhewen , Wang Changyang , Tabibi Sajad , Cheong Joon Wayn
Published: March 2022

This article presents a review on spaceborne Global Navigation Satellite System Reflectometry (GNSS-R), which is an important part of GNSS-R technology and has attracted great attention from academia, industry and government agencies in recent years. Compared with ground-based and airborne GNSS-R approaches, spaceborne GNSS-R has a number of advantages, including wide coverage and the ability to sense medium- and large-scale phenomena such as ocean eddies, hurricanes and tsunamis. Since 2014, about seven satellite missions have been successfully conducted and a large number of spaceborne data were recorded. Accordingly, the data have been widely used to carry out a variety of studies for a range of useful applications, and significant research outcomes have been generated. This article provides an overview of these studies with a focus on the basic methods and techniques in the retrieval of a number of geophysical parameters and the detection of several objects. The challenges and future prospects of spaceborne GNSS-R are also addressed.