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[Objective] To promote efficient utilization and sustainable development of territorial space, this study identified changes in territorial space functions considering different population shrinking characteristics, aiming to explore territorial space optimization strategies in response to population shrinking challenges. [Methods] By integrating multi-source data from county units in Sichuan Province from 2010 to 2020, this study measured population shrinking and territorial space function changes, and delineated territorial space zones based on population shrinking characteristics using elasticity coefficient. [Results] (1) The relationship between population demand and territorial space supply is the main driver of territorial space function formation and development. Population shrinking affects demand, driving changes in agricultural space management, urban space organization, and ecological space management patterns, thereby reshaping the pattern of territorial space functions. (2) Population shrinking in counties of Sichuan Province exhibited significant spatial differences and agglomeration characteristics, with 69.4% of the counties experiencing population shrinkage. This phenomenon was mainly concentrated in peripheral counties outside the central Chengdu area, as well as in most counties in the southern, northeastern, and southwestern parts of Sichuan. The simultaneous change of population quantity and structure, termed “dual shrinking”, was the main type observed. (3) The overall distribution of territorial space functions in counties of Sichuan showed a high in southeast and low in northwest spatial pattern. From 2010 to 2020, 74.9% of the counties experienced an enhancement in territorial space function. (4) Based on population shrinking characteristics, Sichuan’s county territorial space was divided into growth-oriented, extensive, lagging, intensive, declining, and deteriorating types. Territorial space optimization directions were proposed according to the population challenges and territorial space function changes faced by different types of areas. [Conclusion] Incorporating population aging into the measurement system for population shrinking provides a more comprehensive understanding of regional population shrinking characteristics.Future territorial space optimization at the county level in Sichuan Province should integrate population shrinking characteristics and changes in territorial space functions. This optimization should involve territorial space planning, comprehensive land consolidation, and policy support, optimizing agricultural, urban, and ecological spaces to meet the spatial development needs under varying population shrinking characteristics.

Objective To investigate the protective effect of sevoflurane postconditioning against cerebral ischemia/reperfusion (I/R) injury in rats and its mechanism of action. Methods A total of 80 specific pathogen-free healthy adult male Sprague-Dawley rats were selected and randomly divided into sham-operation group (S group), cerebral I/R group (I/R group), cerebral I/R+sevoflurane postconditioning group (ISP group), and cerebral I/R+sevoflurane postconditioning+nuclear factor ery-throid 2-related factor 2 (Nrf2) inhibitor group (ISPB group), with 20 rats in each group. All rats except those in the S group were used to establish a rat model of cerebral I/R injury using the suture method for occlusion of the middle cerebral artery for 2 h, followed by reperfusion for 24 h, and for the rats in the S group, threading was performed below the middle cerebral artery without ligation. The rats in the ISP group were given inhalation of 3% sevoflurane immediately after reperfusion for 30 min, and those in the ISPB group were given intraperitoneal injection of the Nrf2 inhibitor brusatol (2 mg/kg) at 30 min before ischemia in addition to the treatment in the ISP group. After successful modeling, neurological deficit score was used to eval-uate the degree of neurological impairment. Left ventricular blood samples and pathological sections of brain tissue were obtained, and 2,3,5-triphenyltetrazolium chloride staining was used to determine the percentage of cerebral infarct volume; enzyme-linked immunosorbent assay was used to measure the serum levels of inflammatory factors (interleukin-1β [IL-1β] and tumor necrosis factor-α [TNF-α]) and oxidative stress-related factors (malondialdehyde [MDA] and superoxide dismutase [SOD]); Western blotting was used to mea-sure the expression of apoptosis-related proteins (B-cell lymphoma-2 [Bcl-2], Bcl-2 related x [Bax], and Caspase-3) and Nrf2 signaling pathway-related proteins (Nrf2 and heme oxygenase-1 [HO-1]) in brain tissue; immunofluorescence assay was used to measure the expression of Nrf2 inside and outside the nucleus of brain tissue cells. Results Compared with the I/R group, the ISP group had significant reductions in neurological deficit score, the percentage of cerebral infarct volume, the serum levels of IL-1β, TNF-α, and MDA, and the levels of Bax and Caspase-3 in brain tissue (t=5.76-18.39,P

Objective To investigate the protective effect of remimazolam on cerebral nerves in a rat model of cerebral ischemia/reperfusion injury and its mechanism. Methods A total of 50 male Sprague-Dawley rats were randomly divided into sham-operation group (Sham group), cerebral ischemia/reperfusion group (I/R group), I/R+remimazolam (RE) group, I/R+RE+LY294002 (LY) group, and I/R+LY group. Neurological deficit score was used to evaluate the degree of neurological dysfunction. After arterial blood samples and brain tissue pathological sections were collected from the rats in each group, 2,3,5-trip-henyltetrazolium chloride staining was performed for the brain tissue sections to calculate cerebral infarct volume ratio; ELISA was used to measure the serum levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α); Western blotting was used to measure the relative expression levels of protein kinase B (AKT), phosphorylated AKT (p-AKT), nuclear factor-kappa B p65 (NF-κB p65), and phosphorylated NF-κB p65 (p-NF-κB p65) in brain tissue, and then immunofluorescence assay was used to measure the expression level of p-NF-κB p65 inside and outside the nucleus of cells in brain tissue. Results There were significant differences between these groups in cerebral infarct volume ratio, neurological deficit score, the serum levels of IL-6, IL-1β, and TNF-α, the relative expression levels of p-AKT and p-NF-κB p65, p-AKT/AKT ratio, and p-NF-κB p65/NF-κB p65 ratio (F=72.41-654.90,P

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown once again that coronavirus (CoV) in animals are potential sources for epidemics in humans. Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen of swine with a worldwide distribution. Here, we implemented and described an approach to analyze the epidemiology of PDCoV following its emergence in the pig population. We performed an integrated analysis of full genome sequence data from 21 newly sequenced viruses, along with comprehensive epidemiological surveillance data collected globally over the last 15 years. We found four distinct phylogenetic lineages of PDCoV, which differ in their geographic circulation patterns. Interestingly, we identified more frequent intra- and interlineage recombination and higher virus genetic diversity in the Chinese lineages compared with the USA lineage where pigs are raised in different farming systems and ecological environments. Most recombination breakpoints are located in the ORF1ab gene rather than in genes encoding structural proteins. We also identified five amino acids under positive selection in the spike protein suggesting a role for adaptive evolution. According to structural mapping, three positively selected sites are located in the N-terminal domain of the S1 subunit, which is the most likely involved in binding to a carbohydrate receptor, whereas the other two are located in or near the fusion peptide of the S2 subunit and thus might affect membrane fusion. Finally, our phylogeographic investigations highlighted notable South-North transmission as well as frequent long-distance dispersal events in China that could implicate human-mediated transmission. Our findings provide new insights into the evolution and dispersal of PDCoV that contribute to our understanding of the critical factors involved in CoVs emergence.

Mid‐infrared (MIR) lasers generated by nonlinear optical (NLO) crystals have aroused extensive attention in various military and civilian applications. Among the MIR NLO crystal family, LiInSe2 (LISe) is a promising candidate in the generation of MIR lasers due to its wide transmission range, large bandgap, and high laser‐induced damage threshold. However, the intrinsic defects in LISe induce optical losses, which will induce laser damage and hinder the performance of MIR laser generation. In this work, the mechanism of optical absorption induced by defects is revealed in LISe through transient absorption (TA) spectroscopy. It is verified that the deep‐level defects in LISe give rise to the extra optical absorption, which is owing to the excited state absorption (ESA) and photo‐induced absorption (PIA). Accordingly, for improving the optical properties of LISe crystals, Li2Se vapor‐mediated annealing to reduce defects concentration is rationally designed. The results confirmed that the optical properties of annealed LISe are improved due to the decrease of defects concentration. Ultimately, the performance of MIR laser generation is successfully enhanced by using the annealed LISe crystal. This work provides deep insights into the defect‐induced absorption losses in LISe crystals and promotes the application of LISe crystals in MIR laser generation. [ABSTRACT FROM AUTHOR]