Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Foods ; 13(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38890979

RESUMO

The present study aimed to systematically investigate the underlying differences in flesh quality between wild and farmed Monopterus albus. Fifteen healthy M. albus per group with an average body weight of 45 g were sampled to analyze muscle parameters by biochemical indicators, histomorphology, and molecular biology. Compared with the wild fish, the farmed M. albus in flesh had lower crude protein, collagen, lysine, histidine, total amino acids, SFA, n-3 PUFA contents, and n-3/n-6 ratio (p < 0.05), and higher moisture, crude lipid, crude ash, MUFA, n-6PUFA, and total PUFA contents (p < 0.05). The thawing loss, drip loss, steaming loss, and boiling loss in the farmed group were significantly higher, and hardness, springiness, cohesiveness, gumminess, chewiness, and resilience were significantly lower than those in the wild group (p < 0.05). In addition, higher muscle fiber density and lower muscle fiber diameter were observed in wild M. albus (p < 0.05). In muscle transcriptome profiling, differentially expressed genes and enriched pathways are primarily associated with muscle development, protein synthesis, catabolism, lipid metabolism, and immunity. To the best of our knowledge, this is the first investigation that compares the flesh quality between wild and farmed M. albus in terms of biochemistry, histology, and molecular biology levels. Overall, wild M. albus had a higher nutritional value and texture quality than farmed M. albus.

2.
Front Immunol ; 15: 1411544, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38915412

RESUMO

Fish intestinal health under intensive aquaculture mode plays an important role in growth, development, and immune function. The present study was aimed to systematically investigate the differences of intestinal health between wild and cultured Monopterus albus by biochemical parameters, histomorphology, and molecular biology. A total of 15 healthy M. albus per group, with an average body weight of 45 g, were sampled to analyze intestinal health parameters. Compared with wild fish, the cultured M. albus in the foregut had lower trypsin, lipase, SOD, CAT, T-AOC, and GSH-Px activities (P < 0.05) and higher amylase activity and MDA content (P < 0.05). The villus circumference and goblet cells in the cultured group were significantly lower than those in the wild group (P < 0.05). In addition, the cultured fish showed lower relative expression levels of occludin, zo-1, zo-2, claudin-12, claudin-15, mucin5, mucin15, lysozyme, complement 3, il-10, tgf-ß1, tgf-ß2, and tgf-ß3 (P < 0.05) and higher il-1ß, il-6, il-8, tnf-a, and ifnγ mRNA expressions than those of wild fish (P < 0.05). In terms of gut microbiota, the cultured group at the phylum level displayed higher percentages of Chlamydiae and Spirochaetes and lower percentages of Firmicutes, Bacteroidetes, Actinobacteria, Cyanobacteria, and Verrucomicrobia compared to the wild group (P < 0.05). At the genus level, higher abundances of Pseudomonadaceae_Pseudomonas and Spironema and lower abundances of Lactococcus and Cetobacterium were observed in the cultured group than in the wild group (P < 0.05). To our knowledge, this is the first investigation of the intestinal health status between wild and cultured M. albus in terms of biochemistry, histology, and molecular biology levels. Overall, the present study showed significant differences in intestinal health between wild and cultured M. albus and the main manifestations that wild M. albus had higher intestinal digestion, antioxidant capacity, and intestinal barrier functions than cultured M. albus. These results would provide theoretical basis for the subsequent upgrading of healthy aquaculture technology and nutrient regulation of intestinal health of cultured M. albus.


Assuntos
Aquicultura , Microbioma Gastrointestinal , Intestinos , Smegmamorpha , Animais , Intestinos/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/imunologia , Citocinas/metabolismo , Animais Selvagens
3.
BMJ Open ; 13(11): e072279, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37977869

RESUMO

OBJECTIVES: This study was designed to identify the patterns, prevalence and risk factors of intimate partner violence (IPV) against female adolescents and its association with mental health problems. DESIGN: Cross-sectional survey. SETTINGS: Dumuria Upazila (subdistrict) under the Khulna district of Bangladesh. PARTICIPANTS: A total of 304 participants were selected purposively based on some specifications: they must be female adolescents, residents of Dumuria Upazila and married during the COVID-19 pandemic when under 18 years of age. OUTCOME MEASURES: By administering a semi-structured interview schedule, data were collected regarding IPV using 12 five-point Likert scale items; a higher score from the summation reflects frequent violence. RESULTS: The findings suggest that the prevalence of physical, sexual and emotional IPV among the 304 participants, who had an average age of 17.1 years (SD=1.42), was 89.5%, 87.8% and 93.7%, respectively, whereas 12.2% of the participants experienced severe physical IPV, 9.9% experienced severe sexual IPV and 10.5% experienced severe emotional IPV. Stepwise regression models identified age at marriage (p=0.001), number of miscarriages (p=0.005), education of spouse (p=0.001), income of spouse (p=0.016), age gap between spouses (p=0.008), marital adjustment (p<0.001) and subjective happiness (p<0.001) as significant risk factors. Hierarchical regression, however, indicated that age at marriage (p<0.001), age gap between spouses (p<0.001), marital adjustment (p<0.001) and subjective happiness (p<0.001) had negative associations with IPV, while the number of miscarriages (p<0.001) had a positive relationship. Pearson's correlation showed that IPV was significantly associated with depression, anxiety and stress. CONCLUSION: During the COVID-19 pandemic, an increase in IPV and mental health problems among early married adolescents was documented. To reduce physical and mental harm and to assure their well-being, preventive and rehabilitative measures should be devised.


Assuntos
Aborto Espontâneo , COVID-19 , Violência por Parceiro Íntimo , Maus-Tratos Conjugais , Gravidez , Humanos , Adolescente , Feminino , Estudos Transversais , Casamento , Prevalência , Bangladesh/epidemiologia , Aborto Espontâneo/epidemiologia , Pandemias , COVID-19/epidemiologia , Violência por Parceiro Íntimo/psicologia , Fatores de Risco , Nível de Saúde
4.
Biologia (Bratisl) ; 78(3): 873-885, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36573069

RESUMO

Bacillary dysentery is a type of dysentery and a severe form of shigellosis. This dysentery is usually restricted to Shigella infection, but Salmonella enterica and enteroinvasive Escherichia coli strains are also known as this infection's causative agents. The emergence of drug-resistant, bacillary dysentery-causing pathogens is a global burden, especially for developing countries with poor hygienic environments. This study aimed to isolate, identify, and determine the drug-resistant pattern of bacillary dysentery-causing pathogens from the stool samples of the Kushtia region in Bangladesh. Hence, biochemical tests, serotyping, molecular identification, and antibiotic profiling were performed to characterize the pathogens. Among one hundred fifty (150) stool samples, 18 enteric bacterial pathogens were isolated and identified, where 12 were Shigella strains, 5 were S. enterica sub spp. enterica strains and one was the E.coli strain. Among 12 Shigella isolates, 8 were Shigella flexneri 2a serotypes, and 4 were Shigella sonnei Phage-II serotypes. Except for three Salmonella strains, all isolated strains were drug-resistant (83%), whereas 50% were multidrug-resistant (MDR), an alarming issue for public health. In antibiotic-wise analysis, the isolated pathogens showed the highest resistance against nalidixic acid (77.78%), followed by tetracycline (38.89%), kanamycin (38.89%), amoxicillin (27.78%), streptomycin (27.78%), cefepime (22.22%), ceftriaxone (22.22%), ampicillin (16.67%), ciprofloxacin (16.67%), and chloramphenicol (16.67%). The existence of MDR organisms that cause bacillary dysentery in the Kushtia area would warn the public to be more health conscious, and physicians would administer medications cautiously. The gradual growth of MDR pathogenic microorganisms needs immediate attention, and the discovery of effective medications must take precedence. Supplementary information: The online version contains supplementary material available at 10.1007/s11756-022-01299-x.

5.
Autism ; : 13623613221135297, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36373750

RESUMO

LAY ABSTRACT: A nationwide survey was done in Bangladesh to assess autism spectrum disorder prevalence in 16- to 30-month-old children at urban-rural distribution and to determine the association with socioeconomic and demographic conditions. A three-stage cluster sampling method was used where districts from all divisions were selected in the first stage, census enumeration areas as blocks of households were selected in the second stage and households (within the blocks) were selected in the third stage. Thereby, it included 38,440 children from 37,982 households (71% rural, 29% urban) aged 16-30 months from 30 districts of eight divisions of Bangladesh. Screening was done with a 'Red Flag' tool and Modified Checklist for Toddlers and a final diagnosis using Diagnostic and Statistical Manual of Mental Disorders, 5th Edition for autism spectrum disorder. Autism spectrum disorder prevalence was 17 per 10,000 young children - in other words, one in 589 young children. Boys were found at higher risk of autism (one in 423 boys; one in 1026 girls). Prevalence of autism spectrum disorder was higher in urban environments than in rural ones - 25/10,000 and 14/10,000, respectively. More autism spectrum disorder children were found in advanced age groups of parents, especially mothers, and in households with a higher wealth quintile. This survey is significant as it covers both urban and rural areas and specifically targets very young children. The involvement of the Bangladesh Bureau of Statistics, as well as support from the entire healthcare system infrastructure, makes this survey more representative on a national level. Its results will form a database to support the development of an effective early intervention programme in Bangladesh. We hope it will prove useful for researchers, clinicians and frontline healthcare workers, and inform the decisions of policymakers and funders in Bangladesh.

6.
Life (Basel) ; 12(11)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36362971

RESUMO

Potassium (K) improves the stress tolerance of crop plants, which varies on the timing of K application and crop varieties. Soybean is a promising crop that can easily fit with the cropping pattern during kharif I season, when water logging occurs due to sudden rain. Therefore, an experiment was conducted to determine the effect of K management on the productivity and seed quality of soybean under normal and waterlogged conditions. The treatments comprised three factors, namely soybean genotypes (BU Soybean-1 and BU Soybean-2), waterlogging (WL) (control and WL for 4 days at the flowering stage (FS)), and K application (full dose as basal and 50% as basal +50% as top dress after termination of the flooding). The trial was laid out in a randomized complete block design with three replications. Findings revealed that BU Soybean-1 produced a higher number of pods and seeds pod-1 under control conditions with basal application of K. On the other hand, BU Soybean-2 produced taller plants and heavier grain, improving grain and straw yield under WL conditions when K was top dressed. The varieties absorbed a higher amount of nitrogen, phosphorus, and potassium under control conditions compared to WL when K was top dressed. Similarly, the seed protein content of both varieties was higher in the control condition with a top dressing of K. However, a higher percentage of seed germination was obtained from BU Soybean-2 in the control condition with a top dressing of K. Further, more electrical conductivity and more mean germination time were recorded in the case of BU Soybean-2 under WL with the basal application of K. Split application of 50% of recommended K fertilizer after the recession of flood water could be suggested for improved grain yield in flood-affected soybean growing areas.

7.
ACS Omega ; 7(45): 41096-41099, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36406580

RESUMO

It is essential to determine the heat storage efficiency of shape-stabilized phase change materials (ss-PCMs). In two published articles, the formula for heat storage efficiency is presented using two distinct equations. Using the two equations, the calculated values for heat storage efficiency revealed significant discrepancies. The outcomes cannot be compared. The evaluation of heat storage efficiency has a substantial impact on the practical application of PCMs and serves as a performance benchmark for the PCM samples that have been tested. In this paper, the correct equations for calculating the efficiency of heat storage are presented. Furthermore, it is essential to note that the methods used to calculate the supercooling value are not straightforward. Consequently, this paper clarified the correct formula and/or method for determining the supercooling value and heat storage efficiency of ss-PCMs.

8.
J Anim Sci ; 100(10)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35913826

RESUMO

The objective of this study was to investigate the dietary effects of Eucommia ulmoides bark and leaf (EB, EL) supplementation on the growth, lipid metabolism, flesh quality, and transcriptome of grass carp (Ctenopharyngodon idellus). EB and EL were individually added to the basal diet (control) at concentrations of 20 g/kg and 40 g/kg, respectively, and then the three diets were fed to grass carp (59.7 ±â€…0.3 g) for 60 d. The results showed that the weight gain was improved, and the feed conversion ratio was decreased by supplementation with EB and EL (P < 0.05). Compared to the control, the EB and EL groups showed higher flesh hardness; water-holding capacity; and collagen, docosahexaenoic acid (DHA), and n-3 polyunsaturated fatty acids (n-3PUFAs) contents and lower mesenteric lipid and muscle crude lipid contents (P < 0.05). Moreover, dietary EB and EL supplementation increased the activities of superoxide dismutase and glutathione peroxidase and decreased the contents of malondialdehyde and protein carbonyl in flesh (P < 0.05). In muscle transcriptome profiling, a total of 979, 1980 differentially expressed genes (DEGs) were identified, and 29, 199 Gene Ontology (GO) terms and 13, 39 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched in the EB and EL groups, respectively. Some key pathways and genes involved in promoting growth, lipid metabolism and flesh quality were obtained, including mTOR and PPAR signaling pathways, muscle cytoskeleton- and extracellular matrix-related genes (myosin and collagen), etc. Overall, dietary EB and EL supplementation improved the growth, lipid metabolism, and flesh quality of grass carp, and several potential pathways and genes were identified behind the improvement mechanism of EB and EL supplementation.


As a traditional herb, Eucommia ulmoides (E. ulmoides) has been utilized in East Asia for at least 2 000 years. In recent years, E. ulmoides has been applied in the culture of fish for its functions of promoting growth, lipid metabolism, and flesh quality. However, the underlying molecular mechanism of improving growth, lipid metabolism, and flesh quality is not well understood. Our study showed that the improvement of flesh quality is the combined effect of antioxidant capacity, muscle texture, water-holding capacity, and nutritional composition. Additionally, several potential pathways and differentially expressed genes were identified through RNA sequencing to further study the improvement mechanism of dietary E. ulmoides bark and leaf supplementation on growth, lipid metabolism, and flesh quality in fish.


Assuntos
Carpas , Eucommiaceae , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Ácidos Docosa-Hexaenoicos , Eucommiaceae/genética , Eucommiaceae/metabolismo , Glutationa Peroxidase/metabolismo , Metabolismo dos Lipídeos , Malondialdeído , Receptores Ativados por Proliferador de Peroxissomo/genética , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Casca de Planta/metabolismo , Folhas de Planta/metabolismo , Superóxido Dismutase/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Transcriptoma , Água
9.
ACS Omega ; 7(26): 22657-22670, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35811917

RESUMO

Doping the SiO2 support with Co, Ni, Zn, and Sc improves the thermal conductivity of a hybrid PEG/SiO2 form-stable phase change material (PCM). Doping also improves the energy utilization efficiency and speeds up the charging and discharging rates. The thermal, chemical, and hydrothermal stability of the PEG/Zn-SiO2 and PEG/Sc-SiO2 hybrid materials is better than that of the other doped materials. The phase change enthalpy of PEG/Zn-SiO2 is 147.6 J/g lower than that of PEG/Sc-SiO2, while the thermal conductivity is 40% higher. The phase change enthalpy of 155.8 J/g of PEG/Sc-SiO2 PCM is very close to that of the parent PEG. PEG/Sc-SiO2 also demonstrates excellent thermal stability when subjected to 200 consecutive heating-cooling cycles and outstanding hydrothermal stability when examined under a stream at 120 °C for 2 h. The supercooling of the PEG/Sc-SiO2 system is the lowest among the tested materials. In addition, the developed PCM composite has a high energy storage capacity and high thermal energy storage/release rates.

10.
Polymers (Basel) ; 14(9)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35566870

RESUMO

Hydrogen bonding in polyurethane (PU) is imposed by molecular parameters. In this study, the effect of structural isomerism of certain monomers on hydrogen bonding of waterborne polyurethane (WBPU) was studied theoretically and experimentally. Two dihydroxybenzene (DHB)-based structural isomers such as catechol (CC) and hydroquinone (HQ), with different OH positions on the inner benzene core, had been used. Two series of WBPU dispersions were prepared using CC and HQ with defined contents. The binding energies between the catechol (CC)/hydroquinone (HQ) (respective OH group) and urethane/urea were calculated theoretically. By using a density functional theory (DFT) method, it was found that the largest binding energy between the urea and CC was higher than that of urea and HQ. The FT-IR analysis of synthesized polymer was also carried out to compare the results with the theoretical values. The CC-based polymers showed a stronger hydrogen bond both theoretically and experimentally than those for HQ-based polymers. The higher level of hydrogen bond was reflected in their properties of CC-based polymers. The adhesive strength, thermal stability, and hydrophobicity were higher for CC-based materials than those for HQ-based materials. The adhesive strength was increased 25% with the addition of 2.0 wt% CC content. This adhesive strength slightly deviated at a moderately high temperature of 80 °C.

11.
Polymers (Basel) ; 14(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35566966

RESUMO

In this study, a novel hybrid sol-gel coating on AA3003 substrate was developed and the effects of various waste material additives on the reinforcement of the sol-gel coating and the anticorrosion properties in the saline medium were investigated. Egg shell, crumb rubber, activated carbon obtained for pyrolysis of waste rubber tire, waste rubber tire, cement kiln dust, and ST100 additives were tested as reinforcement materials. The AFM characterization results of the coating formulations on AA3003 alloy revealed enhanced roughness values for the modified coatings as compared to the base coating. Similarly, no significant changes were detected in the Fourier transform infrared spectroscopy (FTIR) absorption peaks of the hybrid polymeric material upon loading it with the waste additives, while slight changes in the hydrophobic properties of the final modified coatings were observed as a result of the modification process. Electrochemical impedance spectroscopy (EIS) results revealed that the hybrid sol-gel coating had a promising potential for the protection of the AA3003 substrate against corrosion in the saline medium. However, the loaded additives negatively affected the corrosion resistance properties of the parent hybrid sol-gel coating. For instance, the egg shell additive had the least negative effect on the barrier properties, whereas the cured coating layer of the sample loaded with cement and clay additives showed some disintegration, inhomogeneity, and low barrier properties on the metal surface.

12.
Front Psychiatry ; 13: 1074208, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36683997

RESUMO

Background: Due to unemployment, the prolonged lockdown during the COVID-19 pandemic caused panic and deepened poverty, especially among lower-class and marginal people. The related financial crises led to harmful practices such as the early marriage of adolescent girls, which deteriorated these girl's mental state. Aims: This study attempted to assess the prevalence of mental health problems among early married girls and determine the associated predictors of the growing mental health burden. Methods: This cross-sectional survey was conducted during the third wave of the COVID-19 pandemic in Dumuria Upazila in the Khulna district of Bangladesh. Data were collected purposively from 304 girls who were married off during the COVID-19 pandemic, this was carried out between 22 July and 31 August 2022 by administering a semi-structured interview schedule, with mental health measured by the depression, anxiety, and stress scale 21 (DASS 21). The data were analyzed using IBM SPSS Statistics (version 25), and multiple linear regression was executed in order to predict mental health problems among early married girls. Results: The findings show that the overall prevalence of depression, anxiety, and stress among early married girls during the COVID-19 pandemic in Bangladesh was 60.9% (95% CI: 0.554-0.663), 74.7% (95% CI: 0.698-0.796), and 23.7% (95% CI: 0.189-0.285). The prevalence was relatively higher among girls from the Sanatan (Hindu) religion and younger girls than among Muslim and older girls, respectively. The multiple linear regressions indicate that age, age at marriage, duration of the marriage, spousal occupation, intimate partner violence (IPV), and subjective happiness were the critical predictors of mental health problems among early married girls. Conclusion: Early marriage, along with various adverse outcomes, i.e., IPV, maladjustment, and poor subjective happiness, has resulted in heightened mental health problems for young girls. Policymakers should implement coercive measures to prevent early marriage, especially during social, economic, political, and health crises; in addition, more research is recommended in order to explore the mechanisms that make early married girls psychologically vulnerable and thus formulate protective and preventive programs for addressing such vulnerabilities.

13.
Polymers (Basel) ; 13(23)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883714

RESUMO

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation-the xanthan gum with 3% NaCl solution-recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.

14.
Polymers (Basel) ; 13(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34641048

RESUMO

A series of UV-protected coatings were prepared using cerium-oxide-functionalized oil fly ash (f-OFA-CeO2) in waterborne polyurethane (WBPU) dispersions. Three monomers, namely, poly(tetramethyleneoxide glycol) (PTMG), polydimethylsiloxane-hydroxy terminated (PDMS) and 4,4-dicyclohexylmethane diisocyanate (H12MDI), were used to pre-mix with f-OFA-CeO2 separately, followed by the synthesis of WBPU/f-OFA-CeO2 dispersions. The f-OFA-CeO2 distribution and enrichment into any part (top/bottom/bulk) of the coating was strongly affected by the pre-mixing of f-OFA-CeO2. The f-OFA-CeO2 was densely distributed in the top, bottom and bulk when the f-OFA-CeO2 was pre-mixed with PDMS, H12MDI and PTMG, respectively. Only an f-OFA-CeO2-enriched top surface showed excellent UV protection. The lowest UV-degraded exposed coating was found when the top surface of the coating was f-OFA-CeO2-enriched.

15.
ACS Omega ; 6(35): 22909-22921, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34514262

RESUMO

Nanosheets consisting of two-dimensional (2-D) nanomaterials made up of Ca2+ (Ca), and Y3+ (Y) cations and carbonate [CO3 2-] anions in the interlayer with a uniform thickness and lengths of around 10 µm have been successfully synthesized in a hydrotalcite layer structure, otherwise known as a layered double hydroxide, using a facile hydrothermal method. The resulting CaY-CO3 2- layered double-hydroxide (LDH) materials demonstrate outstanding affinity and selectivity for toxic transition metal ions such as Cr3+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, and Hg2+ as well as metalloid As3+. The adsorption of all of the highly toxic metal ions from the aqueous solution was found to be exceptionally rapid and highly selective, with more than 95% removal achieved within 30 min. For AsO3, a strong adsorption potential of 452 mg/g was observed at pH 7.0, which is better than most values previously reported. The distribution coefficient K d values can exceed ∼106 mL/g for Cr3+, Pb2+, and As3+, which are highly toxic. The fabricated materials have excellent chemical stability: they retain their well-defined lamellar shapes even under mildly acidic conditions.

16.
Nanomaterials (Basel) ; 11(7)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206694

RESUMO

The properties of polyethylene glycol-6000 (PEG)/MgCaCO3, a low-cost shape-selective phase change material (ss-PCM), make it highly suitable for solar thermal applications. Nanosized porous MgO-doped CaCO3 with Mg molar concentrations of 5%, 10%, and 15% were synthesized using a hydrothermal technique. The prepared MgO-CaCO3 matrices were then impregnated with PEG to obtain PEG/MgCaCO3 as an ss-PCM. Samples identified as PEG-5MgCaCO3 (P-5-MCC), PEG-10MgCaCO3 (P-10-MCC), and PEG-15MgCaCO3 (P-15-MCC) were prepared and studied. Interestingly, P-10-MCC has the smallest particle size together with a good porous structure compared to the other two materials. The results of thermogravimetric analyses and differential scanning calorimetry indicate that the small particle size and porous structure facilitate the impregnation of approximately 69% of the PEG into the 10-MCC matrix. The latent heat and energy storage efficiency of PEG in the P-10-MCC sample are 152.5 J/g and 96.48%, respectively, which are significantly higher than those of comparable materials. Furthermore, in addition to the improvement of the thermal conductivity of the P-10-MCC, its supercooling is also reduced to some extent. The combined mesoporous and macro-porous structure of P-10-MCC is critical to retaining a large amount of PEG within the matrix, resulting in a high latent heat in the operating temperature range of 35-57 °C. The P-10MCC sample also demonstrates a high energy storage capacity (98.59%), high thermal energy storage/release rates, and exceptional shape-stabilized PCM properties.

17.
Chem Rec ; 21(7): 1631-1665, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34132038

RESUMO

Nanotechnology has transformed the world with its diverse applications, ranging from industrial developments to impacting our daily lives. It has multiple applications throughout financial sectors and enables the development of facilitating scientific endeavors with extensive commercial potentials. Nanomaterials, especially the ones which have shown biomedical and other health-related properties, have added new dimensions to the field of nanotechnology. Recently, the use of bioresources in nanotechnology has gained significant attention from the scientific community due to its 100 % eco-friendly features, availability, and low costs. In this context, jute offers a considerable potential. Globally, its plant produces the second most common natural cellulose fibers and a large amount of jute sticks as a byproduct. The main chemical compositions of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute as an ideal source of pure nanocellulose, nano-lignin, and nanocarbon preparation. It has also been used as a source in the evolution of nanomaterials used in various applications. In addition, hemicellulose and lignin, which are extractable from jute fibers and sticks, could be utilized as a reductant/stabilizer for preparing other nanomaterials. This review highlights the status and prospects of jute in nanotechnology. Different research areas in which jute can be applied, such as in nanocellulose preparation, as scaffolds for other nanomaterials, catalysis, carbon preparation, life sciences, coatings, polymers, energy storage, drug delivery, fertilizer delivery, electrochemistry, reductant, and stabilizer for synthesizing other nanomaterials, petroleum industry, paper industry, polymeric nanocomposites, sensors, coatings, and electronics, have been summarized in detail. We hope that these prospects will serve as a precursor of jute-based nanotechnology research in the future.


Assuntos
Celulose/química , Corchorus/química , Lignina/química , Nanocompostos/química , Nanotecnologia/tendências , Animais , Catálise , Celulose/isolamento & purificação , Humanos , Lignina/isolamento & purificação , Nanopartículas Metálicas/química , Oxirredução
18.
J Autism Dev Disord ; 51(7): 2392-2401, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32975665

RESUMO

This study explored the physical and clinical phenotype of Bangladeshi children with autism spectrum disorder (ASD). A totally of 283 children who were referred for screening and administered Module 1 of the Autism Diagnostic Observation Schedule (ADOS) were included. Overall, 209 met the ADOS algorithmic cutoff for ASD. A trend for greater weight and head circumference was observed in children with ASD versus non-ASD. Head circumference was significantly (p < 0.03) larger in ASD males compared with non-ASD males. A trend was also observed for symptom severity, higher in females than males (p = 0.068), with further analyses demonstrating that social reciprocity (p < 0.014) and functional play (p < 0.03) were significantly more impaired in ASD females than males. The findings help understand sex differences in ASD.


Assuntos
Transtorno do Espectro Autista/etnologia , Transtorno do Espectro Autista/patologia , Fatores Sexuais , Adolescente , Bangladesh/etnologia , Peso Corporal , Cefalometria , Criança , Pré-Escolar , Feminino , Cabeça/patologia , Humanos , Masculino , Fenótipo , Exame Físico , Índice de Gravidade de Doença , Comportamento Social
19.
Chem Rec ; 20(12): 1568-1595, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33078557

RESUMO

Heavy fuel oil ash (HFOA) is generated as an industrial waste material during the combustion of heavy fuel oil in power/desalination plants. With increasing energy demands, a significant volume of HFOA is generated. It is generally disposed of in landfills, causing environmental pollution, as it contains several toxic elements. Recently, efforts were made towards developing strategies for reusing industrial waste materials and creating value-added products from the waste materials. Despite significant information available in the literature on the utilization of HFOA, there is still a need for a thorough and systematic review on the characterization and utilization of HFOA in various applications. Consequently, this paper aims to present a critical review of the literature on HFOA generation, its chemical composition, physical properties, morphology, and applications. It is encouraging to note that HFOA has been used in several potential applications, such as the preparation of activated carbon and carbon nanotubes, metal recovery, environmental pollutant removal, polymer composites and construction materials, etc. However, the development of several value-added materials utilizing HFOA and its applications in other areas such as coatings, cathodic protection systems, and phase change materialswould emerge as a new topic of research. It is expected that this review will act as a precursor for further research on the use of HFOA in industrial applications. Since the use of HFOA will lead to environmental, economic, and technical benefits, research in the utilization of this industrial waste material is highly recommended.

20.
Polymers (Basel) ; 12(9)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872169

RESUMO

We prepared a series of polyurethane (PU) coatings with defined contents using poly(tetramethylene oxide)glycol (PTMG) with two different molecular weights (i.e., Mn = 2000 and 650), as well as polydimethyl siloxane (PDMS) with a molecular weight of Mn 550. For every coating, maximum adhesive strength and excellent self-healing character (three times) were found using 6.775 mol% mixed with low-molecular-weight-based polyols (PU-11-3-3). Defined 1.0 wt% CeO2 was also used for the PU-11-3-3 coating (i.e., PU-11-3-3-CeO2) to obtain UV shielding properties. Both the in situ polymerization and blending processes were separately applied during the preparation of the PU-11-3-3-CeO2 coating dispersion. The in situ polymerization-based coating (i.e., PU-11-3-3-CeO2-P) showed similar self-healing properties. The PU-11-3-3-CeO2-P coating also showed excellent UV shielding in real outdoor exposure conditions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA