A performance degradation model of nitrile butadiene rubber (NBR) O-rings for hydrogen permeation effects under high-pressure.

The integration of molecular chain changes on a microscopic scale to achieve macroscopic performance is crucial in degradation processes concerning O-ring seals. Nonetheless, a comprehensive and compelling mathematical model that can describe molecular chains' material properties and macroscopic material properties simultaneously for O-rings under high-pressure conditions is yet to be established. In this paper, we propose a degradation model based on viscoelasticity and molecular chain statistics for hydrogen permeation. The proposed model aims to establish the relationship between the material molecular chains and macroscopic material properties, with a primary focus on accurately recognizing the performance degradation process of rubber sealing rings. We verify the model's reliability through uniaxial tensile strength experiments and high-pressure hydrogen immersion experiments, respectively. Predictions of the model exhibit favorable conformity with the experimental data concerning the above phenomena. Furthermore, we derive the number of molecular chains and maximum strain of the degradation process. Based on the similarity of the degradation process's descent, it is plausible to speculate that NBR properties' degradation can be characterized by the average number of molecular chains.

Oil tanker under ice loadings.

As a result of global warming, the area of the polar pack ice is diminishing, making merchant travel more practical. Even if Arctic ice thickness reduced in the summer, fractured ice is still presenting operational risks to the future navigation. The intricate process of ship-ice interaction includes stochastic ice loading on the vessel hull. In order to properly construct a vessel, the severe bow forces that arise must be accurately anticipated using statistical extrapolation techniques. This study examines the severe bow forces that an oil tanker encounters when sailing in the Arctic Ocean. Two stages are taken in the analysis. Then, using the FEM program ANSYS/LS-DYNA, the oil tanker bow force distribution is estimated. Second, in order to estimate the bow force levels connected with extended return periods, the average conditional exceedance rate approach is used to anticipate severe bow forces. The vessel's itinerary was planned to take advantage of the weaker ice. As a result, the Arctic Ocean passage took a meandering route rather than a linear one. As a result, the ship route data that was investigated was inaccurate with regard to the ice thickness data encountered by a vessel yet skewed with regard to the ice thickness distribution in the region. This research intends to demonstrate the effective application of an exact reliability approach to an oil tanker with severe bow forces on a particular route.

Suppression of hepatocellular carcinoma by Ulva lactuca ulvan via gut microbiota and metabolite interactions.

INTRODUCTION: Ulva lactuca polysaccharide (ULP) is green algae extract with numerous biological activities, including anticoagulant, anti-inflammatory, and antiviral effects. However, the inhibitory ability of ULP in the development of hepatocellular carcinoma warrants further studies. OBJECTIVES: To elucidate the anti-tumor mechanism of ULP action and evaluate its regulatory effect on gut microbiota and metabolism in H22 hepatocellular carcinoma tumor-bearing mice. METHODS: An H22 tumor-bearing mouse model was established by subcutaneously injecting H22 hepatoma cells. The gut microbiota composition in cecal feces was assessed and subjected to untargeted metabolomic sequencing. The antitumor activity of ULP was verified further by western blot, RT-qPCR, and reactive oxygen species (ROS) assays. RESULTS: Administration of ULP alleviated tumor growth by modulating the compositions of the gut microbial communities (Tenericutes, Agathobacter, Ruminiclostridium, Parabacteroides, Lactobacillus, and Holdemania) and metabolites (docosahexaenoic acid, uric acid, N-Oleoyl Dopamine, and L-Kynurenine). Mechanistically, ULP promoted ROS production by inhibiting the protein levels of JNK, c-JUN, PI3K, Akt, and Bcl-6, thereby delaying the growth of HepG2 cells. CONCLUSION: ULP attenuates tumor growth in H22 tumor-bearing mice by modulating gut microbial composition and metabolism. ULP inhibits tumor growth mainly by promoting ROS generation.

Plasmodium infection suppresses colon cancer growth by inhibiting proliferation and promoting apoptosis associated with disrupting mitochondrial biogenesis and mitophagy in mice.

BACKGROUND: Colon cancer is a common gastrointestinal tumor with a poor prognosis, and thus new therapeutic strategies are urgently needed. The antitumor effect of Plasmodium infection has been reported in some murine models, but it is not clear whether it has an anti-colon cancer effect. In this study, we investigated the anti-colon cancer effect of Plasmodium infection and its related mechanisms using a mouse model of colon cancer. METHODS: An experimental model was established by intraperitoneal injection of Plasmodium yoelii 17XNL-infected erythrocytes into mice with colon cancer. The size of tumors was observed dynamically in mice, and the expression of Ki67 detected by immunohistochemistry was used to analyze tumor cell proliferation. Apoptosis was assessed by terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) staining, and the expression of apoptosis-related proteins including Bax, Bcl-2, caspase-9, and cleaved caspase-3 was detected by western blot and immunohistochemistry, respectively. Transmission electron microscopy (TEM) was used to observe the ultrastructural change in colon cancer cells, and the expression of mitochondrial biogenesis correlative central protein, PGC-1α, and mitophagy relevant crucial proteins, PINK1/Parkin, were detected by western blot. RESULTS: We found that Plasmodium infection reduced the weight and size of tumors and decreased the expression of Ki67 in colon cancer-bearing mice. Furthermore, Plasmodium infection promoted mitochondria-mediated apoptosis in colon cancer cells, as evidenced by the increased proportion of TUNEL-positive cells, the upregulated expression of Bax, caspase-9, and cleaved caspase-3 proteins, and the downregulated expression of Bcl-2 protein. In colon cancer cells, we found destroyed cell nuclei, swollen mitochondria, missing cristae, and a decreased number of autolysosomes. In addition, Plasmodium infection disturbed mitochondrial biogenesis and mitophagy through the reduced expression of PGC-1α, PINK1, and Parkin proteins in colon cancer cells. CONCLUSIONS: Plasmodium infection can play an anti-colon cancer role in mice by inhibiting proliferation and promoting mitochondria-mediated apoptosis in colon cancer cells, which may relate to mitochondrial biogenesis and mitophagy.

Self-assembled lanthanide-based helixes: synthetic control of the helical handedness by chirality of the ligand.

The control of the self-assembly of lanthanide helical chain and their helical handedness have been investigated for the first time. Δ- and Λ-form lanthanide chain complexes were obtained by introducing thiazolidine ligands that were synthesised from L- and D-cysteine, respectively, and shared the same formula: [Ln2(L)3(H2O)5]∞·3H2O (Ln: Sm and Eu) (L: 2-(2-hydroxy-3,5-dinitrophenyl)thiazolidine-4-carboxylic acid). The crystallographic, circular dichroism, and luminescence properties of these novel lanthanide chain complexes were studied.

Circulating Cell-Free mtDNA Content as a Non-invasive Prognostic Biomarker in HCC Patients Receiving TACE and Traditional Chinese Medicine.

Hepatocellular carcinoma (HCC) accounts for 70-85% of liver cancer, and about 85% of HCC are hepatitis B virus-related (HBV-HCC) in China. Transarterial chemoembolization (TACE) combined with traditional Chinese medicine (TCM) has been reported as an effective treatment. Potential biomarkers to stratify patients who may benefit from this treatment are needed. In this study, we aimed to evaluate whether circulating cell-free mitochondrial DNA (ccf-mtDNA) content was associated with the outcome of HCC patients, especially of those who received the combination treatment of TACE and TCM. Univariate and multivariate Cox analyses were conducted to evaluate the association between ccf-mtDNA content and the overall survival of HBV-HCC patients. Kaplan-Meier analysis was used to compare the survival differences between patients with low and high ccf-mtDNA content. In a hospital-based cohort with 141 HBV-HCC patients, there was no statistically significant association between the ccf-mtDNA content and the overall survival of HBV-HCC patients in the univariate analysis, but a borderline significant association was found in the multivariate analyses. In a subcohort of 50 HBV-HCC patients who received TACE and TCM treatment, high ccfDNA content conferred an increased death risk with a hazard ratio of 4.01 (95% confidence interval: 1.25-12.84, p = 0.019) in the multivariate analysis. Kaplan-Meier survival analysis also showed that patients with high ccf-mtDNA content had unfavorable survival (log rank p = 0.097). Our findings suggest that ccf-mtDNA content is a potential non-invasive prognostic biomarker in HCC patients receiving TACE and TCM treatment.

Cancer Biomarkers Discovery of Methylation Modification With Direct High-Throughput Nanopore Sequencing.

Cancer is a complex disease, driven by a combination of genetic and epigenetic alterations. DNA and RNA methylation modifications are the most common epigenetic events that play critical roles in cancer development and progression. Bisulfite converted sequencing is a widely used technique to detect base modifications in DNA methylation, but its main drawbacks lie in DNA degradation, lack of specificity, or short reads with low sequence diversity. The nanopore sequencing technology can directly detect base modifications in native DNA as well as RNA without harsh chemical treatment, compared to bisulfite sequencing. Furthermore, CRISPR/Cas9-targeted enrichment nanopore sequencing techniques are straightforward and cost-effective when targeting genomic regions are of interest. In this review, we mainly focus on DNA and RNA methylation modification detection in cancer with the current nanopore sequencing approaches. We also present the respective strengths, weaknesses of nanopore sequencing techniques, and their future translational applications in identification of epigenetic biomarkers for cancer detection and prognosis.

eIF2α of Litopenaeus vannamei involved in shrimp immune response to WSSV infection.

The alpha subunit of Eukaryotic Initiation Factor 2 (eIF2α) is a key translation regulator that plays an important role in cellular stress responses, which including virus infection. To investigate whether WSSV infection can activate the PERK-eIF2α pathway, the eIF2α in shrimp Litopenaeus vannamei, designed as LveIF2α, was analyzed. The LveIF2α, a 332-amino acid polypeptide, shares a high degree of similarity with eIF2α from other species, having two eIF2α protein signatures at the 13-88 aa and 192-243 aa. The WSSV challenge experiment showed that the protein level of the total LveIF2α was decreased after infection, while the phosphorylation of LveIF2α has no significant change, which indicated that the phosphorylation ratio of LveIF2α was increased after infection. Furthermore, inhibitor treatment led to a significant decrease of WSSV loads. Moreover, the Binding immunoglobulin protein (BiP), an endoplasmic reticulum (ER) stress sensor, and PERK were also investigated during virus infection and it was shown that they were both up-regulated. Taken together, these results suggested that WSSV infection can induce ER stress and activated the unfolded protein response (UPR), and the PERK-eIF2α pathway is important for innate immune during WSSV infection in shrimp.