Physiological and transcriptomic analysis dissects the molecular mechanism governing meat quality during postmortem aging in Hu sheep (Ovis aries).

Introduction: Hu sheep, known for its high quality and productivity, lack fundamental scientific research in China. Methods: This study focused on the effects of 24 h postmortem aging on the meat physiological and transcriptomic alteration in Hu sheep. Results: The results showed that the 24 h aging process exerts a substantial influence on the mutton color, texture, and water content as compared to untreated group. Transcriptomic analysis identified 1,668 differentially expressed genes. Functional enrichment analysis highlighted the importance of glycolysis metabolism, protein processing in endoplasmic reticulum, and the FcγR-mediated phagocytosis pathway in mediating meat quality modification following postmortem aging. Furthermore, protein-protein interaction analysis uncovered complex regulatory networks involving glycolysis, the MAPK signaling pathway, protein metabolism, and the immune response. Discussion: Collectively, these findings offer valuable insights into the molecular mechanisms underlying meat quality changes during postmortem aging in Hu sheep, emphasizing the potential for improving quality control strategies in mutton production.

Experimental Study on Thermal Conductivity and Hardness of Cu and Ni Nanoparticle Packed Bed for Thermoelectric Application.

The hot-wire method is applied in this paper to probe the thermal conductivity (TC) of Cu and Ni nanoparticle packed beds (NPBs). A different decrease tendency of TC versus porosity than that currently known is discovered. The relationship between the porosity and nanostructure is investigated to explain this unusual phenomenon. It is found that the porosity dominates the TC of the NPB in large porosities, while the TC depends on the contact area between nanoparticles in small porosities. Meanwhile, the Vickers hardness (HV) of NPBs is also measured. It turns out that the enlarged contact area between nanoparticles is responsible for the rapid increase of HV in large porosity, and the saturated nanoparticle deformation is responsible for the small increase of HV in low porosity. With both TC and HV considered, it can be pointed out that a structure of NPB with a porosity of 0.25 is preferable as a thermoelectric material because of the low TC and the higher hardness. Although Cu and Ni are not good thermoelectric materials, this study is supposed to provide an effective way to optimize thermoelectric figure of merit (ZT) and HV of nanoporous materials prepared by the cold-pressing method.

Influence of Nanopore Shapes on Thermal Conductivity of Two-Dimensional Nanoporous Material.

The influence of nanopore shapes on the electronic thermal conductivity (ETC) was studied in this paper. It turns out that with same porosity, the ETC will be quite different for different nanopore shapes, caused by the different channel width for different nanopore shapes. With same channel width, the influence of different nanopore shapes can be approximately omitted if the nanopore is small enough (smaller than 0.5 times EMFP in this paper). The ETC anisotropy was discovered for triangle nanopores at a large porosity with a large nanopore size, while there is a similar ETC for small pore size. It confirmed that the structure difference for small pore size may not be seen by electrons in their moving.

[Effects of scorpion venom heat-resistant protein on kainic acid induced-damage of cultured primitive rat hippocampal neuropeptide Y-nergic neurons].

AIM: To investigate the effects of scorpion venom heat-resistant protein (SVHRP) on kainic acid induced-damage of cultured primitive rat hippocampal neuropeptide Y-nergic neurons. METHODS: We observed morphological changes, celluar vigor, NPY-immunoreactivity and NPY mRNA expression by means of Thionine staining, MTT assay, immunocytochemistry and RT-PCR, respectively, on the primitively cultured Sprague-Dawley rat hippocampal neuron treated with KA and SVHRP for 24 h. RESULTS: MTT assay and morphologic analysis showed that SVHRP markedly increased neuron survival-rate, and protected them from kA-induced damage. The expression of NPY-immunoreactivity and NPY mRNA in SVHRP group increased obviously compared with other groups. CONCLUSION: SVHRP protected the primitively cultured hippocampal neurons from KA-induced neuroexcitotoxicity and promoted the expression of NPY.

[The protective effect of nicotine on dopaminergic neuron of Parkinson's disease mice].

AIM: To investigate the protective effect of nicotine on dopaminergic neurons and its mechanisms in mice with Parkinson's disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). METHODS: C57BL/6J mice were injected with MPTP for 8 days to establish PD model. Nicotine was given for 10 days in the pretreatment group. Animals were examined behaviorally with the pole test and traction test. Tyrosine hydroxylase (TH) and gamma-aminobutyric acid (GABA) were investigated by the immunocytochemistry (ICC) method. The ultrastructural changes of caudate nucleus(CN) were observed by electron microscope. RESULTS: The results showed that pretreatment nicotine could improve the dyskinesia of PD mice markedly. Simultaneously, TH (P < 0.01) neurons and GABA (P < 0.05) neurons were much more in the pretreatment group when compared with those in the model group. The ultrastructural injury of the pretreatment group was also ameliorated. CONCLUSION: Nicotine has a protective effect on the dopaminergic neurons in the MPTP-treated mice.