Effects of the high pressure homogenization on the viability of yeast cell and volatile components in non-pasteurized rice wine

This study investigated the effects of high pressure homogenization (HPH) to replace a thermal pasteurization on the yeast cell inactivation and the volatile components of rice wine (RW). By applying HPH (172 MPa with 5 passes), the yeast count was reduced over 4 log cycles. The inactivation of yeast cells by HPH and a thermal processing, i.e. Holder pasteurization (HP), was quantitatively analyzed. In terms of the inactivation of yeast cells, the HPH at 172 MPa with 5 passes was equivalent to the HP at 65°C for 3 min. In RW, 34 volatile components were identified, including 8 alcohols, 18 esters, 2 acids, 1 carbonyls, 3 hydrocarbons, and 2 miscellaneous. Fruity volatiles were found more in HPH samples while components having fatty and oily characters were more detected in HP treated samples.     

Deciphering the Potential Neuroprotective Effects of Luteolin against Aβ1–42-Induced Alzheimer’s Disease

The current study was undertaken to unveil the protective effects of Luteolin, a natural flavonoid, against amyloid-beta (Aβ₁–₄₂)-induced neuroinflammation, amyloidogenesis, and synaptic dysfunction in mice. For the development of an AD mouse model, amyloid-beta (Aβ₁–₄₂, 5 μL/5 min/mouse) oligomers were injected intracerebroventricularly (i.c.v.) into mice’s brain by using a stereotaxic frame. After that, the mice were treated with Luteolin for two weeks at a dose of 80 mg/kg/day. To monitor the biochemical changes, we conducted western blotting and immunofluorescence analysis. According to our findings, the infusion of amyloid-beta activated c-Jun N-terminal kinases (p-JNK), p38 mitogen-activated protein kinases, glial fibrillary acidic protein (GFAP), and ionized calcium adaptor molecule 1 (Iba-1) in the cortex and hippocampus of the experimental mice; these changes were significantly inhibited in Aβ₁–₄₂ + Luteolin-treated mice. Likewise, we also checked the expression of inflammatory markers, such as p-nuclear factor-kB p65 (p-NF-kB p65 (Ser536), tissue necrosis factor (TNF-α), and Interleukin1-β (IL-1β), in Aβ₁–₄₂-injected mice brain, which was attenuated in Aβ₁–₄₂ + Luteolin-treated mice brains. Further, we investigated the expression of pro- and anti-apoptotic cell death markers such as Bax, Bcl-2, Caspase-3, and Cox-2, which was significantly reduced in Aβ₁–₄₂ + Lut-treated mice brains compared to the brains of the Aβ-injected group. The results also indicated that with the administration of Aβ₁–₄₂, the expression levels of β-site amyloid precursor protein cleaving enzyme (BACE-1) and amyloid-beta (Aβ₁–₄₂) were significantly enhanced, while they were reduced in Aβ₁–₄₂ + Luteolin-treated mice. We also checked the expression of synaptic markers such as PSD-95 and SNAP-25, which was significantly enhanced in Aβ₁–₄₂ + Lut-treated mice. To unveil the underlying factors responsible for the protective effects of Luteolin against AD, we used a specific JNK inhibitor, which suggested that Luteolin reduced Aβ-associated neuroinflammation and neurodegeneration via inhibition of JNK. Collectively, our results indicate that Luteolin could serve as a novel therapeutic agent against AD-like pathological changes in mice.     

Greenhouse gas emission factor development for coal-fired power plants in Korea

Accurate estimation of greenhouse gas emissions is essential for developing an appropriate strategy to mitigate global warming. This study examined the characteristics of greenhouse gas emission from power plants, a major greenhouse gas source in Korea. The power plants examined use bituminous coal, anthracite, and sub-bituminous coal as fuel. The CO₂ concentration from power plants was measured using GC–FID with methanizer. The amount of carbon, hydrogen, and calorific values in the input fuel was measured using an elemental analyzer and calorimeter. For fuel analysis, CO₂ emission factors for anthracite, bituminous coal, and sub-bituminous coal were 108.9, 88.4, and 97.9 Mg/kJ, respectively. The emission factors developed in this study were compared with those for IPCC. The results showed that CO₂ emission was 10.8% higher for anthracite, 5.5% lower for bituminous coal, and 1.9% higher for sub-bituminous coal than the IPCC figures.     

Bacteria sorting by field-flow fractionation. Application to whole-cell Escherichia coil vaccine strains

Sorting and quantification of deactivated bacteria is an important way of quality control for whole-cell bacterial vaccines. In general, surface features of deactivated bacteria used for whole-cell bacterial vaccines affect the immunoresponse to bacteria-associated antigens. Enumeration of bacteria is also an important process development parameter for these vaccines. Field-flow fractionation (FFF) was previously applied to the separation of bacteria. For the first time, FFF is used for sorting bacteria strains of the same species on the basis of differences in bacterial membrane characteristics. Two FFF techniques, gravitational FFF (GrFFF) and asymmetrical flow FFF (AsFIFFF), are shown to be able to fractionate, distinguish, and quantify different deactivated Escherichia coli strains used for vaccines. E. coli can differ in the presence of fimbriae on the bacterial membrane. Fimbriae affect E. coli pathology and thus the use of E. coli for vaccines. GrFFF and AsFIFFF are able to fractionate fimbriated/ nonfimbriated cells in mixtures of different strains. While GrFFF is characterized by low cost and simplicity, As-FIFFF shows a higher performance in size fractionation with a high-speed separation. Coupled, on-line UV/visible turbidimetry yields the relative numbers of fractionated cells and sample recovery. Scanning electron microscopy and quasi-elastic light scattering are employed as uncorrelated techniques for size and morphology analysis of the E. coli strains.     

Morphology and metabolism of Ba-alginate encapsulated hepatocytes with galactosylated poly(allyl amine) and poly(vinyl alcohol) as extracellular matrices

Lactobionic acid, bearing a -galactose group, was coupled with poly(allyl amine) to provide synthetic extracellular matrices together with poly(vinyl alcohol) (PVA). The hepatocytes were encapsulated in Ba-alginate capsules with galactosylated poly(allyl amine) (GA) and PVA as extracellular matrices. From microscopic observation, it was revealed that the microcapsule prepared has a highly porous structure with interconnected pores and pore sizes ranging between 50–150 nm on both the surface and the cross-section. It was found, from the permeability experiment of microcapsules using FITC-dextrans with different molecular weights, that the capsule has a molecular weight cut off (MWCO) of 120 kDa, showing the potential that it can function as an immunoprotecting wall. The hepatocytes, cultured with GA and PVA in the core of the microcapsule, rapidly aggregated within a day, thus resulting in good metabolic functions such as albumin synthesis and ammonia removal.     

Hollow-fiber flow field-flow fractionation for whole bacteria analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

This work proposes for the first time the use of hollow-fiber flow field-flow fractionation (HF FlFFF) for improved matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOFMS) of whole bacteria. HF FlFFF has proved to be able to prepurify or fractionate different species of whole bacteria. Sample preparation by HF FlFFF gives improved spectra quality because noncellular components possibly present in the sample can be separated from the cells. When a mixture of two bacteria (Bacillus subtilis and Escherichia coli) is fractionated through HF FlFFF, MALDI/TOFMS analysis of each separated bacterial species preserves the most characteristic ion signals of the species without the presence of characteristic signals of the other species. The main advantages of HF FlFFF for MALDI/TOFMS analysis of whole bacteria are miniaturization, simplicity, and low cost of the fractionator components. This low cost makes disposable usage of the fractionator possible, thus eliminating the risk of run-to-run contamination of spectra due to sample carryover. The low fractionator volume yields bacterial fractionation on the order of a few minutes, which is comparable to MALDI/TOFMS analysis time. The small fractionation volume makes sample dilution low enough so that additional sample concentration steps are not strictly required to preserve MALDI/TOFMS detection.     

Development of high-sensitivity ion trap ion mobility spectrometry time-of-flight techniques: a high-throughput nano-LC-IMS-TOF separation of peptides arising from a Drosophila protein extract

A linear octopole trap interface for an ion mobility time-of-flight mass spectrometer has been developed for focusing and accumulating continuous beams of ions produced by electrospray ionization. The interface improves experimental efficiencies by factors of approximately 50-200 compared with an analogous configuration that utilizes a three-dimensional Paul geometry trap (Hoaglund-Hyzer, C. S.; Lee, Y. J.; Counterman, A. E.; Clemmer, D. E. Anal. Chem. 2002, 74, 992-1006). With these improvements, it is possible to record nested drift (flight) time distributions for complex mixtures in fractions of a second. We demonstrate the approach for several well-defined peptide mixtures and an assessment of the detection limits is given. Additionally, we demonstrate the utility of the approach in the field of proteomics by an on-line, three-dimensional nano-LC-ion mobility-TOF separation of tryptic peptides from the Drosophila proteome.     

A new life extension method for high cycle fatigue using micro-martensitic transformation in an austenitic stainless steel

Most of the conventional strengthening methods for metals and alloys such as work hardening, precipitation hardening, cause a decrease in ductility and are not very effective for cyclic loading. In this study, a new strengthening method, which is effective for high cycle fatigue, has been developed. The intersections of dislocations in a stainless steel are freezed by very fine martensite particles, which are supposed to suppress dislocation motion at low stress amplitudes. Fatigue life in a high cycle regime increased >60 times, and no decrease in ductility was observed in tensile tests, as compared to a work-hardened stainless steel.