In this article, 9, 9‐bis (4‐aminophenyl)‐2, 7‐dihydroxy‐fluorene (BADHF) was synthesized using methylsulfonic acid as catalyzer by direct condensation. Two kinds of novel multifunctional benzoxazine ...monomers containing fluorenyl groups and hydroxyl groups (MB‐FH) were obtained from the chemical reaction of BADHF, salicylaldehyde, paraformaldehyde, and ethanolamine (or diethyleneglycolamine) through the adoption of o‐hydroxy‐benzylamine method and one‐step Mannich condensation reaction method. In the traditional three‐step synthesis method, the double bond reduction process took 8–12 h, but in this article, it only took 15 min. The structures of MB‐FH monomers and their intermediates were characterized by Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR). The curing behaviors, curing kinetics, and thermal properties of MB‐FH monomers were tested by using a dynamic rheometer, differential scanning calorimeter (DSC), FTIR, dynamic mechanical analysis (DMA), and thermogravimetric analyzer (TGA). The curing induction time can be apparently shortened by the introduction of hydroxyl groups into benzoxazine monomers, and it can catalyze the ring‐opening polymerization of oxazine rings at lower temperatures, and improve the interaction of hydrogen bonds in the structure of polybenzoxazine.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In the current study, 1 wt%, NaOH treated pine cone (ATPC) particles composites with bisphenol‐A aniline based benzoxazine (BA‐a) matrix were prepared by isothermal compression method. Ultimate ...impacts of ATPC reinforcement on the thermomechanical, tensile, flexural, and impact properties of the composites were studied by using a dynamic mechanical analyzer (DMA), a Universal testing machine, and a Tinius‐Olsen impact device, respectively. The thermal stability of ATPC particles was remarkably increased, TGA confirmed that particles will not be degraded during the curing. The DMA results of 30 wt% ATPC reinforced composites confirmed that the glass transition temperature, storage modulus, and loss modulus were 22°C, 2510, and 250 MPa higher than the neat matrix, respectively. In addition, the impact strength of the 30 wt% ATPC reinforced composites was nearly 3 times higher than the neat matrix, which confirmed that the matrix's brittleness is reduced, similar observation was confirmed by the Brostow and coworkers empirical model. Moreover, a gradual rise in the tensile and flexural properties was also recorded. We can easily conclude from the studied parameters that the ATPC particles can be used as a sustainable agro‐waste in polymeric composites.
Biobased polymeric composites have wide applications in interior application. However, the reinforcement of feed stock materials in composites raised serious concerns due to the increasing population. Research is increasing on the use of waste bio mass as reinforcing materials. The use of alkali treated pine cone powder as reinforcing material in polybenzoxazine also showed that the composites thermomechanical and mechanical enhanced.
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This study investigated the effects of xylooligosaccharide (XOS) supplementation on growth, intestinal enzyme, antioxidant and immune‐related genes in common carp Cyprinus carpio fed a high‐fat diet ...(HFD). One hundred and ninety two fish with an initial weight of 19.61 ± 0.96 g were allocated into 24 tanks (eight fish per tank in four replicate) and were fed the control diet, HFD, HFD with 0.5%, 1%, 2% and 3% XOS supplementation. From the result, fish offered HFD with 1% XOS supplementation significantly obtained a higher body mass index and feed efficiency ratio, whereas condition factor was higher in fish fed HFD supplemented with 2% XOS but no difference was attributed to other supplemented group compared to control group. Also, fish fed HFD supplemented with 1%–2% XOS significantly improved protease, lipase, creatine kinase and sodium/potassium ATPase activities compared to other groups. Fish offered HFD were significantly lower in superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX), myeloperoxidase, acid phosphatase, lysozyme activities and immunoglobulin content, but the opposite result was found for aspartate transaminase, alanine transaminase activities, malondialdehyde, protein carbonyl and cortisol content as compared with the control. However, this effect was reversed with HFD supplemented with XOS. Also, interleukin 1β, interleukin 8, tumour necrosis factors, interferons, caspase‐3 and caspase‐9 in the intestine were all up‐regulated in the HFD group, while the reverse pattern was found in SOD, GPX, lysozyme‐C, complement 3 and mucin 5b (muc5b), than the control group. These effects were all enhanced by feeding the XOS diet, especially those fed 1%–3% supplementation. In conclusion, XOS inclusion can improve the growth, digestive enzymes, antioxidants and immune response of common carp fed HFD.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Coronavirus can cross the species barrier and infect humans with a severe respiratory syndrome. SARS-CoV-2 with potential origin of bat is still circulating in China. In this study, a prediction ...model is proposed to evaluate the infection risk of non-human-origin coronavirus for early warning.
The spike protein sequences of 2666 coronaviruses were collected from 2019 Novel Coronavirus Resource (2019nCoVR) Database of China National Genomics Data Center on Jan 29, 2020. A total of 507 human-origin viruses were regarded as positive samples, whereas 2159 non-human-origin viruses were regarded as negative. To capture the key information of the spike protein, three feature encoding algorithms (amino acid composition, AAC; parallel correlation-based pseudo-amino-acid composition, PC-PseAAC and G-gap dipeptide composition, GGAP) were used to train 41 random forest models. The optimal feature with the best performance was identified by the multidimensional scaling method, which was used to explore the pattern of human coronavirus.
The 10-fold cross-validation results showed that well performance was achieved with the use of the GGAP (g = 3) feature. The predictive model achieved the maximum ACC of 98.18% coupled with the Matthews correlation coefficient (MCC) of 0.9638. Seven clusters for human coronaviruses (229E, NL63, OC43, HKU1, MERS-CoV, SARS-CoV, and SARS-CoV-2) were found. The cluster for SARS-CoV-2 was very close to that for SARS-CoV, which suggests that both of viruses have the same human receptor (angiotensin converting enzyme II). The big gap in the distance curve suggests that the origin of SARS-CoV-2 is not clear and further surveillance in the field should be made continuously. The smooth distance curve for SARS-CoV suggests that its close relatives still exist in nature and public health is challenged as usual.
The optimal feature (GGAP, g = 3) performed well in terms of predicting infection risk and could be used to explore the evolutionary dynamic in a simple, fast and large-scale manner. The study may be beneficial for the surveillance of the genome mutation of coronavirus in the field.
In this work, hazelnut shell (HS) particles were added to the bisphenol‐A aniline‐based benzoxazine (BA‐a) matrix and micro‐sized HS particles of varying weight percent (5%, 10%, 15%, 20%, 25%) were ...successfully blended with BA‐a resin. The effects of reinforcing HS particles to the neat matrix were studied. The curing behavior, mechanical properties, and thermal degradation of the composites were performed using differential scanning calorimetry, tensile and impact tests, and thermogravimetric analysis. Glass transition temperature (Tg) was lowered to 16°C which is 4% less than the neat matrix, increase in char yield (Yc) was recorded in composites. Tensile and impact strength of the prepared composites was improved significantly. There was 82.6% increase in Young's modulus and 74.1% increase in the tensile stress for the BA‐a/HS composite containing 25 wt% HS particles. Meanwhile, the impact strength of the composites was elevated, and a maximum of 207% increase in impact strength was observed without sacrificing other properties of the matrix. Additionally, finite element analysis was carried out on a cantilever beam designed in CATIA V5 with the properties of neat BA‐a and HS filled composites. The stress analysis was observed on different HS filled composites, showing better results for HS filled composites as compared to neat polymer.
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This study was conducted to investigate the effects of fructooligosaccharide (FOS) and Bacillus licheniformis (B. licheniformis) and their interaction on innate immunity, antioxidant capability and ...disease resistance of triangular bream Megalobrama terminalis (average initial weight 30.5 ± 0.5 g). Nine experimental diets were formulated to contain three FOS levels (0, 0.3% and 0.6%) and three B. licheniformis levels (0, 1 × 10(7), 5 × 10(7) CFU g(-1)) according to a 3 × 3 factorial design. At the end of the 8-week feeding trial, fish were challenged by Aeromonas hydrophila (A. hydrophila) and survival rate was recorded for the next 7 days. The results showed that leucocyte counts, alternative complement activity as well as total serum protein and globulin contents all increased significantly (P < 0.05) as dietary B. licheniformis levels increased from 0 to 1 × 10(7) CFU g(-1), while little difference (P > 0.05) was observed in these parameters in terms of dietary FOS levels. Both plasma alkaline phosphatase and phenoloxidase activities were significantly (P < 0.05) affected only by dietary FOS levels with the highest values observed in fish fed 0.6 and 0.3% FOS, respectively. Both immunoglobulin M content and liver superoxide dismutase (SOD) activity were significantly affected (P > 0.05) by both FOS and B. licheniformis. Liver catalase, glutathione peroxidase as well as plasma SOD activities of fish fed 1 × 10(7) CFU g(-1)B. licheniformis were all significantly (P < 0.05) higher than that of the other groups, whereas the opposite was true for malondialdehyde content. After A. hydrophila challenge, survival rate was not affected (P > 0.05) by either FOS levels or B. licheniformis contents, whereas a significant (P < 0.05) interaction between these two substances was observed with the highest value observed in fish fed 0.3% FOS and 1 × 10(7) CFU g(-1)B. licheniformis. The results of this study indicated that dietary FOS and B. licheniformis could significantly enhance the innate immunity and antioxidant capability of triangular bream, as well as improve its disease resistance. The best combination of these two prebiotics and/or probiotics was 0.3% FOS and 1 × 10(7) CFU g(-1)B. licheniformis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In the current study, an isothermal compression molding process was used to develop enhanced green composites made from alkali‐treated pine nut shell particles (TPS) reinforced in fully bio‐driven ...benzoxazine (VB) and epoxy (EP) copolymer. Reinforcement with varying weight percent (wt%) of bio‐filler enhanced the properties of composites. Composites showed a rise of 75.9 MPa, 5.8 GPa, and 5.1 kJ/m2 in flexural strength, modulus, and impact strength, respectively. Thermal stability shows that composites can endure higher temperatures and hence be classified as flame‐retardant materials. The dynamic mechanical analysis (DMA) confirms that composites exhibit higher storage modulus, which was elevated to 77.6% compared to the unfilled copolymer. FTIR spectroscopy analyzed the structure of copolymerized composites. Further, finite element analysis (FEA) was observed for the prepared composites. A transversely isotropic composite material model was created with the properties of composites, and stress analysis was observed. FEA outcomes are in good agreement with experimental findings.
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A 12‐week nutritional research was conducted to evaluate the influences of benfotiamine on the growth performance, oxidative stress, inflammation and apoptosis in Megalobrama amblycephala ...(45.25 ± 0.34 g) fed high‐carbohydrate (HC) diets. Six diets were prepared, containing the control diet (30% carbohydrate, C), the HC diet (43% carbohydrate) and the HC diet supplemented with four benfotiamine levels (0.7125 (HCB1), 1.425 (HCB2), 2.85 (HCB3) and 5.7 (HCB4) mg/kg). HC diet remarkably decreased DGC, GRMBW, liver T‐AOC, SOD and CAT activities, SIRT1 protein expression as well as the mRNA levels of SIRT1, Nrf2, CAT, Mn‐SOD and IL10 in liver compared with the C group, but the opposite trend was found in plasma activities of AST and ALT, and contents of IL1β and IL6, liver contents of MDA and mRNA levels of Keap1, NF‐κB, TNF α, IL1β, IL6, Bax, caspase 3, caspase 9 and P53. As for benfotiamine supplementation, HCB2 diet remarkably increased DGC, GRMBW, liver T‐AOC, SOD and CAT activities, SIRT1 protein expression as well as liver mRNA levels of SIRT1, Nrf2, CAT, Mn‐SOD, IL10 and Bcl2, while the opposite was true for plasma AST and ALT activities, and IL1β and IL6 contents, liver MDA contents as well as mRNA levels of Keap1, NF‐κB, TNF α, IL1β, IL6, Bax, caspase 3, caspase 9 and P53. In summary, benfotiamine (1.425 mg/kg) promoted the growth, and alleviated the oxidative stress, inflammation and apoptosis of M. amblycephala fed HC diets through the SIRT1‐mediated signaling pathway.
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A novel boron‐containing hyperbranched benzoxazine (HB‐B) was synthesized from the reaction of triethanolamine borate (BAE), bisphenol‐A, and paraformaldehyde via Mannich condensation. The chemical ...structures of BAE and HB‐B were characterized by Fourier transform infrared (FT‐IR) and hydrogen nuclear magnetic resonance (1H NMR). Afterward, the boron‐containing hyperbranched benzoxazine/epoxy resin copolymers (E51/HB‐B) were prepared. The curing behavior of ‐B and E51/HB‐B was studied by FT‐IR and differential scanning calorimeter (DSC). The thermal stability and flame retardancy properties of the cured HB‐B and E51/HB‐B were evaluated by thermogravimetric analyzer (TGA), limited oxygen index (LOI), UL94 rating test, and microscale combustibility calorimeter experiments (MCC). The initial thermal decomposition temperature and glass transition temperature steadily dropped with increasing HB‐B content, while the char yield kept rising. The LOI value of the E51/HB‐B‐12 wt% was 31.8%, meeting the UL94 V‐0 specification. The result of heat release capacity (HRC) decreased by 20.4%. Moreover, the mechanical properties were also improved, and the tensile strength of E51/HB‐B copolymer was increased by 88.5%. Finally, the fracture morphology of E51/HB‐B was characterized by SEM.
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