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The Tibetan Plateau (TP) has undergone significant warming and humidification in recent years, resulting in rapid permafrost degradation and spatiotemporal variations in hydrological processes, such as subsurface water transport, hydrothermal conversion, and runoff generation. Understanding the mechanisms of hydrological processes in permafrost areas under changing climate is crucial for accurately evaluating hydrological responses on the TP. This study comprehensively discusses the permafrost hydrological processes of the TP under changing climate. Topics include climate conditions and permafrost states, subsurface water transport under freeze–thaw conditions, development of thermokarst lakes and hydrothermal processes, and runoff response during permafrost degradation. This study offers a comprehensive understanding of permafrost changes and their hydrological responses, contributing significantly to water security and sustainable development on the TP.

Abstract Background A cost-effective Escherichia coli expression system has gained popularity for producing virus-like particle (VLP) vaccines. However, the challenge lies in balancing the endotoxin residue and removal costs, as residual endotoxins can cause inflammatory reactions in the body. Results In this study, porcine parvovirus virus-like particles (PPV-VLPs) were successfully assembled from Decreased Endotoxic BL21 (BL21-DeE), and the effect of structural changes in the lipid A of BL21 on endotoxin activity, immunogenicity, and safety was investigated. The lipopolysaccharide purified from BL21-DeE produced lower IL-6 and TNF-α than that from wild-type BL21 (BL21-W) in both RAW264.7 cells and BALB/c mice. Additionally, mice immunized with PPV-VLP derived form BL21-DeE (BL21-DeE-VLP) showed significantly lower production of inflammatory factors and a smaller increase in body temperature within 3 h than those immunized with VLP from BL21-W (BL21-W-VLP) and endotoxin-removed VLP (ReE-VLP). Moreover, mice in the BL21-DeE-VLP immunized group had similar levels of serum antibodies as those in the BL21-W-VLP group but significantly higher levels than those in the ReE-VLP group. Furthermore, the liver, lungs, and kidneys showed no pathological damage compared with the BL21-W-VLP group. Conclusion Overall, this study proposes a method for producing VLP with high immunogenicity and minimal endotoxin activity without chemical or physical endotoxin removal methods. This method could address the issue of endotoxin residues in the VLP and provide production benefits.

In China, porcine reproductive and respiratory syndrome virus (PRRSV) vaccines are widely used. These vaccines, which contain inactivated and live attenuated vaccines (LAVs), are produced by MARC-145 cells derived from the monkey kidney cell line. However, some PRRSV strains in MARC-145 cells have a low yield. Here, we used two type 2 PRRSV strains (CH-1R and HuN4) to identify the genes responsible for virus yield in MARC-145 cells. Our findings indicate that the two viruses have different spread patterns, which ultimately determine their yield. By replacing the viral envelope genes with a reverse genetics system, we discovered that the minor envelope proteins, from GP2a to GP4, play a crucial role in determining the spread pattern and yield of type 2 PRRSV in MARC-145 cells. The cell-free transmission pattern of type 2 PRRSV appears to be more efficient than the cell-to-cell transmission pattern. Overall, these findings suggest that GP2a to GP4 contributes to the spread pattern and yield of type 2 PRRSV.

Objective To detect the expression level of circular RNA (circRNA) hsa_circ_005230 in the plasma of primary hepatocellular carcinoma (HCC), and to explore its clinical value in the diagnosis and prognosis of HCC. Methods The non-coding RNA high-throughput sequencing data in the GEO database was used to screen the circRNA expression in HCC (cancer tissue/paracancerous tissue). RT-qPCR was used to detect hsa_circ_005230 in the plasma of 60 HCC patients, 30 hepatitis B patients and 30 healthy people. Expression levels and their relationship with clinicopathological characteristics of HCC patients were evaluated. The receiver operating characteristic(ROC) curve to evaluate the clinical value of hsa_circ_005230 in the diagnosis of HCC. Survival analysis was performed by Kaplan-Meier method, and multivariate prognostic analysis was performed by Cox regression. Results The most significant up-regulated expression was found in hsa_circ_005230 from the GEO database. The expression level of hsa_circ_005230 in plasma of HCC patients was significantly higher than that of hepatitis B group and healthy control group (P＜0.01); The increase of hsa_circ_005230 expression was related to tumor size (P＜0.05) and to the stage of tumor lymph node metastasis(P＜0.01); ROC analysis showed that the area under the ROC curve (AUC) of plasma hsa_circ_005230 in differentiating HCC from healthy people was 0.69, the sensitivity was 70%,and the specificity was 82 %.The overall survival rate of patients with high hsa_circ_005230 level was significantly lower than that of patients with low hsa_circ_005230 level. Univariate analysis showed that alpa-fetoprotein(AFP)(P＜0.01) and hsa_circ_005230 (P＜0.01) were related factors affecting the prognosis of HCC. Cox multivariate analysis revealed that hsa_circ_005230 was an independent prognostic indicator in HCC patients. Conclusions The hsa_circ_005230 may be used as a new biological marker for the diagnosis and prognostic evaluation of HCC.

Recombination is a pervasive phenomenon in RNA viruses and an important strategy for accelerating the evolution of RNA virus populations. Recombination in the porcine reproductive and respiratory syndrome virus (PRRSV) was first reported in 1999, and many case reports have been published in recent years. In this review, all the existing reports on PRRSV recombination events were collected, and the genotypes, parental strains, and locations of the recombination breakpoints have been summarized and analyzed. The results showed that the recombination pattern constantly changes; whether inter- or intra-lineage recombination, the recombination hotspots vary in different recombination patterns. The virulence of recombinant PRRSVs was higher than that of the parental strains, and the emergence of virulence reversion was caused by recombination after using MLV vaccines. This could be attributed to the enhanced adaptability of recombinant PRRSV for entry and replication, facilitating their rapid propagation. The aim of this paper was to identify common features of recombinant PRRSV strains, reduce the recombination risk, and provide a foundation for future research into the mechanism of PRRSV recombination.

Based on the gas kinetic scheme (GKS), numerical simulation research on the thermal protection system with the spike was carried out from the independent flow field and the fluid-structure interaction. The reliability of the algorithm in independent flow field was first verified by using the standard cylindrical model, and then the effectiveness and mechanism of the heat reduction of spike were analyzed by comparing the aerothermal characteristics and the corresponding flow field characteristics of the cylindrical model without/with the spike. After verification by applying GKS to the coupled simulation of flow field/structure temperature field, the heat reduction performance of spike under the fluid-structure interaction was further analyzed. The results show that the heat reduction performance of spike increases with the advancement of the fluid-structure interaction time, which is beneficial to the long-term cruise flight of the hypersonic vehicle.

Due to the copper (Cu) active sites, its complexes with oxidase-like activity have superior catalytic properties, which can catalyze a series of specific substrates like 3,3′,5,5′-tetramethylbenzidine (TMB), producing colorimetric reactions for the detection of different reducing small-molecule compounds. Attribute to the competitive coordination effects between water molecules and central Cu ions, most of the Cu complexes can hardly be used in the pure aqueous reaction system. In this study, a Cu-based material (Cu-imidazole-2-carboxaldehyde, Cu-ICA) was prepared using copper ions and ICA through a one-step process in the water solution. After the morphology of the material being characterized, the mimetic enzyme behavior of the Cu-ICA was demonstrated through the TMB oxidation. Compared to the other reported oxidase-like mimics, Cu-ICA has better aqueous stability and oxidase-like activity, and shows a higher vmax. Furthermore, basing on the oxidase-like activity of Cu-ICA, a colorimetric method was developed for the ascorbic acid and glutathione detections with linear ranges of 0.5–5 μM and 0.5–4 μM, and limit of detection of 0.1304 μM and 0.097 μM, respectively. Owing to its excellent aqueous stability and oxidase-like activity, Cu-ICA has bright application prospects in the analysis of reducing small-molecule compounds.