Self-sustained and Insulated Radiative/Evaporative Cooler for Daytime Subambient Passive Cooling.

Passive cooling technologies are one of the promising solutions to the global energy crisis due to no consumption of fossil fuels during operation. However, the existing radiative and evaporative coolers still have problems achieving daytime subambient cooling while maintaining evaporation over the long term. Here, we propose a self-sustained and insulated radiative/evaporative cooler (SIREC), which consists of a porous polyethylene film (P-PE) at the top, an air layer in the middle, and poly(vinyl alcohol) hydrogel with lithium bromide (PLH) at the bottom. In particular, the P-PE shows high solar reflectance (R̅solar = 0.91) and long-wave infrared transmittance (τ̅LWIR = 0.92), which reflects sunlight while enhancing the direct radiative heat transfer between outer space and PLH (ε̅LWIR = 0.96) for sky radiative cooling. In addition, the desirable vapor permeability (579 s m-1) of the P-PE also results in good compatibility with PLH for evaporative cooling (EC). Moreover, the PLH's ability to harvest atmospheric water at night provides self-sustainment for daytime EC. The air layer between P-PE and PLH further enhances the subambient cooling performance of the SIREC. These findings indicate promising prospects for the integration of passive cooling technologies.

Untargeted Profiling and Differentiation of Volatiles in Varieties of Meat Using GC Orbitrap MS.

Volatile compounds play vital roles in food sensory attributes and food quality. An analysis of volatile compounds could illustrate the sensory attributes at the microscale level. Here, untargeted profiling approaches for volatiles in five most-consumed meat species were established using headspace SPME-GC/high resolution Orbitrap MS. An extended high-resolution database of meat volatile compounds was established to enhance the qualification accuracy. Using sulfur-containing compounds, aldehydes, and ketones as the research model, the parameters including fiber coating types, extraction temperature, extraction time, and desorbing time were optimized. Principle component analysis, volcano analysis and partial least squares discriminant analysis were applied to run the classification and the selection of discriminant markers between meat varieties, respectively. Different varieties could be largely distinguished according to the volatiles' profiles. 1-Octen-3-ol, 1-octen-3-one, 2-pentyl furan and some other furans degraded from n-6 fatty acids would contribute to distinguishing duck meat from other categories, while methyl esters mainly from oleic acid as well as dimethyl sulfoxide and carbon disulfide possibly produced from the sulfur-containing amino acids contributed to the discrimination of beef. Therefore, volatiles' profiling not only could interpret the aroma style in meat but also could be another promising method for meat differentiation and authentication.

Integrated Lipidomic and Metabolomics Analysis Revealing the Effects of Frozen Storage Duration on Pork Lipids.

Frozen storage is an important strategy to maintain meat quality for long-term storage and transportation. Lipid oxidation is one of the predominant causes of the deterioration of meat quality during frozen storage. Untargeted lipidomic and targeted metabolomics were employed to comprehensively evaluate the effect of frozen duration on pork lipid profiles and lipid oxidative products including free fatty acids and fatty aldehydes. A total of 688 lipids, 40 fatty acids and 14 aldehydes were successfully screened in a pork sample. We found that ether-linked glycerophospholipids, the predominant type of lipids, gradually decreased during frozen storage. Of these ether-linked glycerophospholipids, ether-linked phosphatidylethanolamine and phosphatidylcholine containing more than one unsaturated bond were greatly influenced by frozen storage, resulting in an increase in free polyunsaturated fatty acids and fatty aldehydes. Among these lipid oxidative products, decanal, cis-11,14-eicosenoic acid and cis-5,8,11,14,17-dicosapentaenoic acid can be considered as potential indicators to calculate the freezing time of unknown frozen pork samples. Moreover, over the three-month frozen storage, the first month was a rapid oxidation stage while the other two months were a slow oxidation stage.

Lipid metabolism is a novel and practical source of potential targets for antiviral discovery against porcine parvovirus.

How parvovirus manipulates host lipid metabolism to facilitate its propagation, pathogenicity and consequences for disease, is poorly characterized. Here, we addressed this question using porcine parvovirus (PPV) to understand the complex interactions of parvovirus with lipid metabolism networks contributing to the identification of novel and practical antiviral candidates. PPV significantly alters host lipid composition, characteristic of subclasses of phospholipids and sphingolipids, and induces lipid droplets (LDs) formation via regulating calcium-independent PLA2ß (iPLA2ß), phospholipase Cγ2 (PLCγ2), diacylglycerol kinase α (DKGα), phosphoinositide 3-kinase (PI3K), lysophosphatidic acid acyltransferase θ (LPAATθ), and sphingosine kinases (SphK1 and SphK2). PPV utilizes and exploits these enzymes as well as their metabolites and host factors including MAPKs (p38 and ERK1/2), protein kinase C (PKC) and Ca2+ to induce S phase arrest, apoptosis and incomplete autophagy, all benefit to PPV propagation. PPV also suppresses prostaglandin E2 (PGE2) synthesis via downregulating cyclooxygenase-1 (COX-1), indicating PPV hijacks COX-1-PGE2 axis to evade immune surveillance. Our data support a model where PPV to establishes an optimal environment for its propagation and pathogenicity via co-opting host lipid metabolism, being positioned as a source of potential targets.

Metabolic Profile, Bioavailability and Toxicokinetics of Zearalenone-14-Glucoside in Rats after Oral and Intravenous Administration by Liquid Chromatography High-Resolution Mass Spectrometry and Tandem Mass Spectrometry.

Zearalenone-14-glucoside (ZEN-14G), a key modified mycotoxin, has attracted a great deal of attention due to the possible conversion to its free form of zearalenone (ZEN) exerting toxicity. In this study, the toxicokinetics of ZEN-14G were investigated in rats after oral and intravenous administration. The plasma concentrations of ZEN-14G and its major five metabolites were quantified using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The data were analyzed via non-compartmental analysis using software WinNonlin 6.3. The results indicated that ZEN-14G was rapidly hydrolyzed into ZEN in vivo. In addition, the major parameters of ZEN-14G following intravenous administration were: area under the plasma concentration-time curve (AUC), 1.80 h·ng/mL; the apparent volume of distribution (VZ), 7.25 L/kg; and total body clearance (CL), 5.02 mL/h/kg, respectively. After oral administration, the typical parameters were: AUC, 0.16 h·ng/mL; VZ, 6.24 mL/kg; and CL, 4.50 mL/h/kg, respectively. The absolute oral bioavailability of ZEN-14G in rats was about 9%, since low levels of ZEN-14G were detected in plasma, which might be attributed to its extensive metabolism. Therefore, liquid chromatography high-resolution mass spectrometry (LC-HRMS) was adopted to clarify the metabolic profile of ZEN-14G in rats' plasma. As a result, eight metabolites were identified in which ZEN-14-glucuronic acid (ZEN-14GlcA) had a large yield from the first time-point and continued accumulating after oral administration, indicating that ZEN-14-glucuronic acid could serve a potential biomarker of ZEN-14G. The obtained outcomes would prompt the accurate safety evaluation of ZEN-14G.

Application of enzymatic probe sonication for selenium speciation in animal feeds.

Enzymatic probe sonication (EPS) was investigated as a novel and alternative technology for the extraction of five Se species SeCys2, MeSeCys, Se (IV), SeMet and Se (VI) from animal feeds. The critical parameters of EPS such as enzyme types, ultrasonic power, sample/enzyme ratio, extraction time and temperature were carefully optimized. Under current conditions, one sample can be extracted in 60s, in contrast to several hours required by the conventional enzymatic methods Moreover, the extraction is performed in pure water, no further temperature control or pH adjustment is needed, and therefore the risk of species interconvertion is drastically reduced or inhibited. The Se species were separated and quantitatively determined by high-performance liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS), which allows the separation of organic and inorganic Se species in a single chromatographic run. The newly developed method was successfully applied to the determination of Se species in 18 feed samples collected from markets and local farms. Concerning the feed samples studied, the results of this work suggest that stricter measures should be taken to control the Se-enriched feed supplements in terms of Se species.

Development of a subcritical water extraction approach for trace analysis of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in poultry tissues.

Subcritical water extraction was investigated as a novel and alternative technology for the separation of trace amounts of chloramphenicol, thiamphenicol, florfenicol and its major metabolite florfenicol amine from poultry tissues and its results were compared with those of conventional shaking extraction, ultrasonic extraction, and pressurized liquid extraction. Decreasing the polarity of water by successively increasing the extraction temperature from 50°C to 200°C at the moderate pressure enabled selective, highly effective extractions to be performed. Rapid quantification of the target compounds was carried out by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). The critical parameters of subcritical water extraction such as solvent modifier, temperature, pressure, extraction time, and static cycles were varied with control. The optimized extraction procedures using subcritical water as extraction solvent, were carried out on a pressurized liquid extractor operated at 150°C and 100bar, applying two static cycles for 3min. Average recoveries of the four analytes from fortified samples ranged between 86.8% and 101.5%, with relative standard deviations (RSDs) lower than 7.7%. The limits of detection (LODs) and quantification (LOQs) for the target compounds were in the ranges of 0.03-0.5µgkg(-1) and 0.1-2.0µgkg(-1), respectively. The proposed method is fast, sensitive, water-based thus more environmental acceptable, making it a suitable replacement for conventional organic solvent extraction in veterinary drug residue analysis.

Investigations of femtosecond-nanosecond dual-beam laser ablation of dielectrics.

We have conducted experimental investigations for the micromachining of dielectrics (fused silica) using an integrated femtosecond (fs) and nanosecond (ns) dual-beam laser system at different time delays between the fs and ns pulses. We found that the maximum ablation enhancement occurs when the fs pulse is shot near the peak of the ns pulse envelope. Enhancements up to 13.4 times in ablation depth and 50.7 times in the amount of material removal were obtained, as compared to fs laser ablation alone. The fs pulse increases the free electron density and changes the optical properties of fused silica to have metallic characteristics, which increases the absorption of the ns laser energy. This study provides an opportunity for efficient micromachining of dielectrics.

Expression of Bacillus subtilis MA139 beta-mannanase in Pichia pastoris and the enzyme characterization.

The 1014 nucleotides long gene-encoding beta-mannanase from Bacillus subtilis strain MA139 was cloned using PCR. To obtain high expression levels in Pichia pastoris, the beta-mannanase gene was optimized according to the codon usage bias of P. pastoris and fused downstream of GAP promoter. The reconstituted plasmid pGAP-mann was transformed into P. pastoris X-33 strain to constitutively express beta-mannanase. When cultured at 28 degrees Celsius for 3 days protein yields up to 2.7 mg/mL was obtained with the enzyme activity of up to 230 U/mL. In comparison, wild-type gene product yielded 1.9 mg/mL and 170 U/mL, respectively indicating that the protein yield and enzyme activity were significantly improved by codon modification. After purification, the enzyme properties were characterized. The optimal activity was at pH 6.0 and 50 degrees Celsius. In the pH range of 3.0 to 9.0, beta-mannanase showed above 60% of its peak activity. Among the numerous ions tested copper significantly inhibited the enzyme activity. These results suggested that codon-optimized beta-mannanase expressed in P. pastoris could potentially be used as an additive in the feed for monogastric animals.