Effects of ZnCl2/H2O/C2H5OH Treatment on the Filter Paper Performance

Bleached softwood kraft pulp (BSKP) fibers were pretreated in a 5 mol/L NaOH aqueous solution at 35℃ for 90 min. The ZnCl₂/H₂O/C₂H₅OH was used to treat the pretreated BSKP fibers, filter papers were then prepared. In the course of processing, the effects of various molar ratios of ZnCl₂/H₂O/C₂H₅OH on the filter paper performance were evaluated. SEM-EDX was conducted to analyze the physical configuration of the filter papers. Moreover, FT-IR and XPS were performed to further characterize the BSKP, the pretreated BSKP and the filter paper fibers. The results indicated that the fibers treated by ZnCl₂/H₂O/C₂H₅OH were swollen and exhibited slight fibrillation, leading to a looser fiber structure and therefore, enhanced filter paper performance. Air permeability increased from 161.7 L/(m²·s) to 1450.4 L/(m²·s) for the filter papers when the molar ratio of ZnCl₂/H₂O/C₂H₅OH was 1:14:1. The optimum molar ratio of ZnCl₂/H₂O/C₂H₅OH was found to be 1:14:1, and no significant effect of ZnCl₂/H₂O/C₂H₅OH on fibers’ functional groups was detected. These results showed that filtration performance of filter papers was improved when treated with the ZnCl₂/H₂O/C₂H₅OH solution.     

Protective effect of whey protein hydrolysates on H2O2-induced PC12 cells oxidative stress via a mitochondria-mediated pathway

Whey protein hydrolysates (WPHs) were prepared with pepsin and trypsin. A PC12 cell model was built to observe the protective effect of WPHs against H₂O₂-induced oxidative stress. The results indicated that WPHs reduced apoptosis by 14% and increased antioxidant enzyme activities. Flow cytometry was used to assess the accumulation of reactive oxygen species (ROS), Ca²⁺ levels and the mitochondrial membrane potential (MMP). The results showed that WPHs suppressed ROS elevation and Ca²⁺ levels and stabilised MMP by 16%. The anti-apoptosis/pro-apoptosis proteins Bcl-2/Bax and poly (ADP-ribose) polymerase (PARP) were investigated by Western-blot analysis, which indicated that WPHs increased the expression of Bcl-2 while inhibiting the expression of Bax and the degradation of PARP. WPHs also blocked Caspase-3 activation by 62%. The results demonstrate that WPHs can significantly protect PC12 cells against oxidative stress via a mitochondria-mediated pathway. These findings indicate the potential benefits of WPHs as valuable food antioxidative additives.     

Use of low dose e-beam irradiation to reduce E. coli O157:H7, non-O157 (VTEC) E. coli and Salmonella viability on meat surfaces

This study determined the extent that irradiation of fresh beef surfaces with an absorbed dose of 1 kGy electron (e-) beam irradiation might reduce the viability of mixtures of O157 and non-O157 verotoxigenic Escherichia coli (VTEC) and Salmonella. These were grouped together based on similar resistances to irradiation and inoculated on beef surfaces (outside flat and inside round, top and bottom muscle cuts), and then e-beam irradiated. Salmonella serovars were most resistant to 1 kGy treatment, showing a reduction of ≤ 1.9 log CFU/g. This treatment reduced the viability of two groups of non-O157 E. coli mixtures by ≤ 4.5 and ≤ 3.9 log CFU/g. Log reductions of ≤ 4.0 log CFU/g were observed for E. coli O157:H7 cocktails. Since under normal processing conditions the levels of these pathogens on beef carcasses would be lower than the lethality caused by the treatment used, irradiation at 1 kGy would be expected to eliminate the hazard represented by VTEC E. coli.     

Essential rosemary oil protects testicular cells against DNA-damaging effects of H2O2 and DMNQ

Rosemary oil (RO) is popular in the Mediterranean region as a culinary additive which has the ability to protect delicate organs such as liver, brain and heart. We examined the effect of RO consumption on resistance of rat testicular cells (TCs) against DNA-damaging effects of the oxidative agents H₂O₂ and DMNQ and on the activity of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). DNA lesions were detected by conventional and modified comet assay and the activities of GSH-Px and SOD were measured spectrophotometrically. Since TCs represent a mixture of haploid, diploid and tetraploid cells, we used flow cytometry for their differentiation and calculation of DNA-damaging effects of H₂O₂ and DMNQ in cells of different ploidy. The results showed that the oxidative DNA lesions were significantly reduced in TCs from rats administered RO; however, the activity of antioxidant enzymes did not differ in TCs from control and RO-supplemented rats.     

响应面法优化O3/H2O2组合工艺处理制浆中段废水的研究

本研究为提高臭氧（O₃）氧化处理制浆中段废水的COD去除率,以广西某造纸厂制浆中段废水为研究对象,采用O₃/H₂O₂组合工艺对其进行高级氧化处理。分别探究了废水初始pH值、O₃用量、H₂O₂用量、反应时间和搅拌速度等影响因素对废水色度和COD去除效果的影响。为提高最优工艺参数的精确度,对O₃/H₂O₂组合工艺参数进行响应面优化法分析。结果表明,在废水初始pH值=8、H₂O₂用量为1.0 mL/L、O₃用量为480 mg/L的工艺条件下,废水色度为85.7倍,色度去除率为99.3%;COD_Cr达208.2 mg/L,COD_Cr去除率为84.5%。     

Characterisation of monoclonal antibody against aflatoxin B1 produced in hybridoma 2C12 and its single-chain variable fragment expressed in recombinant Escherichia coli

An anti-aflatoxin B₁ monoclonal antibody (anti-AFB₁ mAb) from the hybridoma 2C12 was established and its inhibition concentration fifty (IC₅₀) for AFB₁ and relative cross-reactivities (CRs) to other mycotoxins were estimated to be 8 ng/mL and less than 4% compared with AFB₁ by a competitive direct enzyme-linked immunosorbent assay. For production of anti-AFB₁ single-chain variable fragment (anti-AFB₁ scFv) in recombinant Escherichia coli, its scFv-coding genes were cloned from the hybridoma 2C12. The anti-AFB₁ scFv formed inclusion bodies in the cytoplasm of E. coli required in vitro refolding process and hence recovered to retain binding activity successfully. Surface plasmon resonance analysis resulted that anti-AFB₁ scFv possessed 1.16 × 10⁻⁷ M of equilibrium dissociation constant (K_D), which was about 17 times higher than the parental anti-AFB₁ mAb of 6.95 × 10⁻⁹ M.     

Free radical scavenging activity and comparative proteomic analysis of antioxidative protein against H2O2-induced oxidative stress in neuronal cells

Artemisia annua was enzymatically hydrolyzed by five proteases and seven carbohydrases. All enzymatic extracts scavenged DPPH, hydroxyl and alkyl radicals. Especially, the Protamex among the various proteases and Maltogenase among the various carbohydrases extracts exhibited the highest scavenging activity on hydroxyl radical. The extracts of A. annua clearly reduced neuronal cell death from H₂O₂-induced damage. In addition, a proteomic analysis, two-dimensional electrophoresis (2-DE) and matrix assisted laser desorption ionisation-time of flight/time of flight (MALDI-TOF/TOF) was used to identify the proteins of the neuronal cells whose expressions were or were not altered by the treatment of the Maltogenase extracts which showed the highest hydroxyl radical scavenging activity among all enzymatic extracts for 24 h. The protein characterisation revealed that translation elongation factor Tu (EF-Tu), Immunoglobulin E (IgE) and voltage-dependent anion channel 1 (VDAC-1) were involved in the cell survival effects against H₂O₂-induced apoptosis. These results suggest that EF-Tu, IgE and VDAC-1 have an important role in the reduction of neuronal apoptosis by oxidative stress, and the enzymatic extracts of A. annua shows potent antioxidative activities by regulating EF-Tu, IgE and VDAC-1.     

Prolonged storage of ‘Aledo’ table grapes in a slightly CO2 enriched atmosphere in combination with generators of SO2

The quality of late-harvested (early December) ‘Aledo’ table grapes, during storage at 2±1 °C followed by a period of 4 days at 20 °C in a slightly CO₂ enriched atmosphere in combination with generators of SO₂ in cardboard boxes, was evaluated. The changes in different biochemical parameters indicative of grape quality, such as weight, texture, colour, sugars, organic acids and fungal attacks, was determined. The best quality maintenance was achieved by combining the use of generators of SO₂ with a slightly CO₂ enriched atmosphere. The rates of weight, texture and colour losses were slowed, and both fungal attack and the rachis drying were delayed. During storage at 2 °C, the levels of glucose, fructose and sucrose remained unchanged under all the tested conditions, while levels of tartaric and citric acids showed a sharp increase. However, a slightly CO₂ enriched atmosphere, SO₂ microgenerators and their combination extended the storage period of late-harvested ‘Aledo’ table grapes without relatively affecting their organoleptic characteristics.     

Salmonella, Escherichia coli O157:H7 and E. coli biotype 1 in a pilot survey of imported and New Zealand pig meats

A pilot survey for the pathogens Salmonella and Escherichia coli O157:H7, and E. coli biotype 1 was conducted on 100 New Zealand-produced (domestic) pig carcasses and 110 imported pig meat samples over an 8-month period to assess the likelihood of introduction of novel pathogen strains into New Zealand (NZ), and as a guide for development of a domestic pork National Microbiological Database programme. Salmonella was not isolated from domestic pig carcasses or from pig meat imported from Canada and the USA. The prevalence of Salmonella in imported pig meat was 3.6% (95% CI 1.0–9.0) with positive samples detected from Australian pig meat. The prevalence of E. coli O157:H7 on domestic pig carcasses was 1% (95% CI 0.03–5.4) while the overall prevalence of E. coli O157:H7 in imported pig meat was 1.8% (95% CI 0.2–6.4), detected mainly from Australian but not from Canadian or US pork. All except three samples have an E. coli biotype 1 count of <100 CFU cm⁻² or g⁻¹, indicating good hygiene quality of domestic and imported pig meat. The results demonstrated that importation of uncooked pig meat is a potential route for the introduction of new clones of Salmonella and E. coli O157:H7 into New Zealand.     

Triglycerides constituted of short and medium chain fatty acids and dicarboxylic acids in Momordica charantia, as well as capric acid,inhibit PGE2 production in RAW264.7 macrophages

This study was aimed to identify compounds in bitter gourd (Momordica charantia) ethyl acetate extract (EAE), which inhibit lipopolysaccharide-induced prostaglandin E₂ (PGE₂) production in RAW264.7 cells. Bitter gourd EAE was partitioned between n-hexane and methanol/H₂O (90/10). The hexane fraction was further separated by repeated silica gel chromatographies, and a reverse phase (RP) C18 chromatography. Fraction RP-10 showed the highest inhibition effect on PGE₂ production (Max inhibition = 96%, IC₅₀ = 2.3 μg/ml) and was identified to be triglycerides constituted of short and medium chain fatty acids by ¹H NMR, IR and H–HCOSY, and dicarboxylic acids by GC/MS. Fatty acids with 3–20 carbons were tested for the inhibitory activity, and capric acid exhibited the highest effect (Max inhibition = 99%, IC₅₀ = 6.5 μM). In conclusion, triglycerides composed of short and medium chain fatty acids and dicarboxylic acids in bitter gourd inhibit PGE₂ production, and capric acid is the most potent inhibitor among the fatty acids.     

Ultraviolet irradiation: The generator of Vitamin D2 in edible mushrooms

Fresh Shiitake mushrooms (Lentinula edodes), Oyster mushrooms (Pleurotus ostreatus), Button mushrooms (Agaricus bisporus), and Abalone mushrooms (Pleurotus cystidus) were irradiated with Ultraviolet-A (UV-A; wavelength 315–400 nm), Ultraviolet-B (UV-B; wavelength 290–315 nm), and Ultraviolet-C (UV-C; wavelength 190–290 nm). Irradiation of each side of the mushrooms for 1 h, was found to be the optimum period of irradiation in this conversion. The conversions of ergosterol to vitamin D₂ under UV-A, UV-B, and UV-C were shown to be significantly different (p < 0.01). The highest vitamin D₂ content (184 ± 5.71 μg/g DM) was observed in Oyster mushrooms irradiated with UV-B at 35 °C and around 80% moisture. On the other hand, under the same conditions of irradiation, the lowest vitamin D₂ content (22.9 ± 2.68 μg/g DM) was observed in Button mushrooms.     

Supercritical CO2 extraction of trans-lycopene from Portuguese tomato industrial waste

Supercritical CO₂ extraction of trans-lycopene from Portuguese tomato industrial wastes (skins and seeds) was carried out in a flow apparatus. The effects of moisture content, feed initial composition, particle size, solvent flow-rate, pressure and temperature on the extraction yield and recovery were evaluated.     

Effect of suboptimal temperatures and sublethal CO2 levels on multiplication of Tribolium castaneum (Coleoptera: Tenebrionidae), alone or competing with Cryptolestes ferrugineus (Coleoptera: Cucujidae)

Groups of adults of Tribolium castaneum alone, or in combination with adults of Cryptolestes ferrugineus, were exposed to suboptimal temperatures (15°C, 20°C, and 25°C) and sublethal CO₂ levels (2%, 5%, and 10%) in dry (12%, wet mass basis) and damp (15%, wet mass basis) stored wheat in the laboratory, to investigate effects on population size. The mean adult numbers in single- and mixed-species tests were positively correlated with higher temperature and moisture content and negatively correlated with higher CO₂ levels. Adult numbers in single- and mixed-species tests were lower at sublethal CO₂ levels compared to ambient CO₂ levels at all the test temperatures and decreased in dry grain compared to damp grain. Although, a specific trend was not observed in population inhibition between mixed-species and single-species tests, overall the adult populations of T. castaneum were reduced in the presence of C. ferrugineus. A mathematical model was derived to predict the size of adult populations of T. castaneum alone, or in the presence of C. ferrugineus considering all the variables in this study. The model had an R² value of 0.72 but needs to be validated and refined with field data.     

Conversion of Bioethanol to Olefins over ZrO2 Catalyst

Ethylene and 1,3-butadiene are important organic chemical raw materials. Petroleum hydrocarbon cracking is the most widely used method for ethylene fabrication worldwide. In this study, the use of a ZrO₂ catalyst, which can be easily synthesized, for the efficient conversion of bioethanol to ethylene and 1,3-butadiene was analyzed. X-ray diffraction, transmission electron microscopy, temperature-programmed desorption, and Fourier-transform infrared spectroscopy analyses were used to evaluate the surface properties of ZrO₂. The selectivity of ZrO₂ toward ethylene and 1,3-butadiene was as high as 98.2%. Catalyst selectivity toward dehydration or dehydrogenation products depends on the nature of the weak acid-base catalytic sites, whereas high-strength base and intermediate-strength acid catalytic sites selectively yield ethylene.     

Supercritical CO2 cell breaking extraction of Lycium barbarum seed oil and determination of its chemical composition by HPLC/APCI/MS and antioxidant activity

The extraction parameters for oil extraction from Lycium barbarum seed including extraction pressure, temperature and time were optimized using an orthogonal test design. The optimum conditions for supercritical CO₂ extraction were as follows: extraction pressure, 30 MPa; extraction temperature, 45 °C; dynamic extraction time, 60 min; CO₂ flow, 25 kg/h. The oil yield under the conditions proposed was 19.28 g/100 g. The effect of cell wall breakage pretreatment was investigated by supercritical CO₂ rapid depressurization, and results indicated this pretreatment could result in a rapid and efficient extraction. A sensitive fluorescent reagent 2-(11H-benzo[a]carbazol-11-yl) ethyl 4-methylbenzenesulfonate (BCETS) was utilized as pre-column labeling regent to determine fatty acids (FA) from Lycium barbarum seed oils obtained by different extraction methods. The main FA were: C18:2, C18:1, C16, C20:6, C18:3, and C20. The oil from L. barbarum seed exhibited excellent antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl（DPPH）radical scavenging assay and β-carotene bleaching test, and its antioxidant activity compared well with the references ascorbic acid and α- tocopherol.     

Effects of supplementary folic acid and vitamin B12 on hepatic metabolism of dairy cows according to methionine supply

The present experiment was undertaken to study the interactions between dietary supplements of rumen-protected methionine (RPM) and intramuscular injections of folic acid and vitamin B₁₂, given from 3 wk before calving to 16 wk of lactation, on hepatic metabolism of lactating dairy cows. Sixty multiparous Holstein cows were assigned to 10 blocks of 6 cows each according to their previous milk production. Within each block, 3 cows were fed a diet calculated to supply Met as 1.83% of metabolizable protein, whereas the 3 other cows were fed the same diet supplemented with 18 g of RPM calculated to provide Met as 2.23% of metabolizable protein. Within each level of Met, the cows received no vitamin supplement or weekly intramuscular injections of 160 mg of folic acid alone or combined with 10 mg of vitamin B₁₂. Liver biopsies were taken at 2, 4, 8, and 16 wk of lactation. Liver concentrations of folates and vitamin B₁₂ were increased by their respective supplements but this response to vitamin supplements was altered by methionine supply. Concentrations of total lipids and triglycerides increased in livers of cows fed RPM, whereas concentrations of cholesterol ester, cholesterol, diglycerides, phosphatidylethanolamine, and phosphatidylcholine were not affected. Folic acid, alone or combined with vitamin B₁₂, tended to increase the ratio of phosphatidylcholine to phosphatidylethanolamine. Gene expression of 5,10-methylene-tetrahydrofolate reductase, microsomal transfer protein, and phosphatidylethanolamine methyltransferase were higher in liver of cows fed RPM supplements. The relative mRNA abundance of 5,10-methylene-tetrahydrofolate reductase and methylmalonyl-CoA mutase were increased by the combined injections of folic acid and vitamin B₁₂, whereas those of methionine synthase and methionine synthase reductase were not affected by treatments. These results suggest that increasing supply of methyl groups, as preformed labile methyl groups or through methylneogenesis, affected the methylation cycle but had a limited effect on dairy cow performance. The observed effects of the combined supplement of folic acid and vitamin B₁₂ on lactational performance of dairy cows probably result from an improvement of energy metabolism during early lactation.     

Influence of methionine supply on the response of lactational performance of dairy cows to supplementary folic acid and vitamin B12

The present experiment was undertaken to determine if the effects of supplementary folic acid on lactational performance were caused by improved methylneogenesis and if the supply in vitamin B₁₂ could affect this metabolic pathway. In this eventuality, supplementary Met, a major source of preformed methyl groups, should reduce the requirements for these vitamins. Sixty multiparous Holstein cows were assigned to 10 blocks of 6 cows each according to their previous milk production. Within each block, 3 cows were fed a diet estimated to supply Met as 1.83% metabolizable protein and 3 cows were fed the same diet supplemented with 18 g of rumen-protected methionine (RPM) to supply Met as 2.23% of metabolizable protein. Within each level of Met, cows received no vitamin supplement or weekly intramuscular injections of 160 mg of folic acid alone or combined with 10 mg of vitamin B₁₂ from 3 wk before to 16 wk after calving. There was no treatment effect on dry matter intake during pre- and postcalving periods: 13.4 ± 0.4 and 21.8 ± 0.4 kg/d, respectively. Milk production was not affected by RPM supplementation. Folic acid and vitamin B₁₂ given together tended to increase milk production during the 16 wk of lactation. This effect was more pronounced during the first 4 wk of lactation: 37.5, 37.7, and 40.3 ± 0.9 kg/d for cows receiving no vitamin supplement, folic acid alone, or folic acid combined with vitamin B₁₂, respectively. Milk fat yield was not affected by treatments. Lactose, crude protein, and total solid yields were greater, in early lactation, in cows injected with folic acid and vitamin B₁₂ together but this effect diminished as lactation progressed. Intramuscular injections of folic acid alone or combined with vitamin B₁₂ tended to decrease plasma concentrations of homocysteine from 5.51 μM with no vitamin supplement to 4.54 and 4.77 ± 0.37 μM, respectively. Results of the present experiment suggest that the effects of the combined supplement of folic acid and vitamin B₁₂ on lactational performance of dairy cows were not due to an improvement in methyl groups supply, because RPM supplement, a source of preformed methyl groups, did not alter the cow responsiveness to vitamin supplements.     

Protective effects of triterpenoids from Ganoderma resinaceum on H2O2-induced toxicity in HepG2 cells

Ganoderma resinaceum Boud. (Polyporeseae) has long been used for antioxidant, immunoregulation and liver protection. From the fruiting bodies of G. resinaceum, eight new lanostanoids, lucidones D–G (1–4), 7-oxo-ganoderic acid Z₂ (5), 7-oxo-ganoderic acid Z₃ (6), ganoderesin A (7), and ganoderesin B (8), together with six known lanostanoids (9–14) were isolated. The structures of new compounds were elucidated through extensive spectroscopic analysis. In an in vitro model, ganoderesin B (8), ganoderol B (10) and lucidone A (11) showed inhibitory effects against the increase of ALT and AST levels in HepG2 cells induced by H₂O₂ compared to a control group in the range of their maximum non-toxic concentration (MNTC). However, compounds 8, 10 and 11 displayed no anti-oxidant activities by DPPH assay. Meanwhile, activation for PXR (Pregnane X Receptor) of ganoderesin B (8), ganoderol B (10) and lucidone A (11) was evaluated; ganoderol (10) exhibited a vital activation for PXR-induced CYP3A4 expression. These results suggested that GTs (Ganoderma triterpenoids) exhibited hepatoprotective activities by lowering ALT and AST levels.     

可用于纸基材料书写印刷的SiO2光子晶体自组装性能

本研究采用双基片垂直自组装法和旋涂法制备硅基光子晶体,研究了粒径分布及高温热处理对光子晶体结构色的影响,表征了双尺寸和夹心结构光子晶体的微观形貌和光学特性等性能。结果表明,高温热处理有助于增强光子晶体结构色的鲜艳度,且光子晶体在载玻片上的附着强度增加。随着SiO₂微球粒径的增大,光子禁带的中心波长位置逐渐向长波段移动。对于单分散SiO₂微球,粒径越均一,自组装的光子晶体结构色越鲜艳。与双尺寸晶体相比,均一粒径晶体的自组装有序性更好;L-S-L结构比S-L-S结构的光子晶体排列更加平整有序。高浓度的SiO₂微球乙醇分散液书写在黑色纸基材料上,可以呈现出色彩鲜明和饱和度较高的颜色。     

Optimization of the enzymatic modification of egg yolk by phospholipase A2 to improve its functionality for mayonnaise production

Egg yolk (EY) was enzymatically modified by phospholipase A₂ to improve its functional properties for mayonnaise production. The optimum reaction conditions predicted by response surface methodology were enzyme concentration of 7432 LEU for 74 min in the presence of 11.5% (w/w) salt. The predicted values were in good agreement with the experimental values. The mayonnaise prepared with 6% (w/w) of the enzymatically modified EY (EM-EY) had no significant differences in overall acceptability or in the perceived intensities of umami, nutty flavor, sourness, oiliness, and rancid flavor as compared to the mayonnaise prepared with 8% (w/w) fresh EY. The stability of the mayonnaise prepared with 6% (w/w) EM-EY was greater than that of the mayonnaise prepared with 10% (w/w) fresh EY. Based on the results, EM-EY, when produced at optimum conditions, has great potential to replace fresh EY.