In this paper, the interacting characteristics of febuxostat (FBST), an inhibitor of xanthine oxidase for treating gout patients with hyperuricemia with calf thymus DNA (ctDNA) was investigated through multi-spectroscopic methodologies combined with theoretical calculation for understanding the interacting mode on ctDNA, affinity with ctDNA, interacting forces, as well as the alteration in the conformation of ctDNA after interacting FBST The experimental results demonstrated that interacting FBST with ctDNA formed 1:1 complex, the association constant was 913 M-1 at 298 K, suggesting the affinity of FBST on ctDNA was very weak, the interacting mode of FBST on ctDNA was groove binding, and it inserted into the minor groove with rich A-T region of ctDNA. Based on the results of the thermodynamic analysis and theoretical calculation, it can be inferred that the dominated interacting forces between FBST and ctDNA were van der Waals forces and hydrogen bond. And, interacting FBST with ctDNA was a spontaneous, enthalpy-driven, and exothermic process because of ΔG0 < 0, ΔH0 < 0, and |ΔH0| > T|ΔS0|. The results of the circular dichroism (CD) measurements indicated the conformation of ctDNA was weakly disturbed after interacting with FBST but still maintained B-conform. The studied results offer significant insight into further clarifying whether it has genotoxicity.
Tendon derived stem cells (TDSCs) are the endogenous cell source for tenocyte turnover and tendon functional maintenance. They are also the important cell source for tendon engineering and regeneration. In addition, TDSCs also play an important role in tendinopathy via their non-tenogenic lineage differentiation. It has been well demonstrated that cell shape could determine mesenchymal stem cell (MSC) lineage differentiation. In this study, a parallel microgrooved polydimethylsiloxane (PDMS) membrane (10 µm groove width and 3 µm depth) was employed to investigate the role of cell elongation via this particular topographic surface in directing murine TDSC (mTDSC) lineage differentiation. The results showed that elongated mTDSCs exhibited significantly enhanced the gene expression of tenogenic markers when compared to the spread cells that grew on smooth PDMS membrane including tenomodulin, scleraxis, collagens I, III, and VI, decorin and tenascin (p < 0.05). Meanwhile, stemness related genes such as Nanog, Sox2 and Oct4 were significantly inhibited for their expression in elongated mTDSCs (p < 0.05). When under tri-lineage induced differentiation, cell elongation significantly inhibited mTDSC differentiation towards chondrogenic and adipogenic lineages (p < 0.05). Furthermore, cell elongation could significantly inhibit mTDSC osteogenic lineage differentiation (p < 0.05) induced by BMP-2, a tendinopathy mimicking stimulant. In conclusion, simulation of native tendon structure via using parallel microgrooved topography can promote mTDSC differentiation specifically towards tenogenic lineage and prevent non-tenogenic lineage differentiation, providing an insight into the design of tendon regenerative materials.
Background: Recent studies have identified that transglutaminases (TGMs) are involved in a widespread epigenetic modification in tumorigenesis. However, it remains unclear how transglutaminase 3 (TGM3) affects in pan-cancer. The present study aimed to explore the clinical and prognostic function of TGM3 in pan-cancer as well as to explore the relationship of TGM3 expression with clinical stage, survival rate, prognosis condition, immune infiltration and mutation indicators. Methods: The relevant data of tumors were obtained from The Cancer Genome Atlas (TCGA), TARGET, Cancer Cell Line Encyclopedia (CCLE) and Genotype-Tissue Expression (GTEx) databases. According to the Human Protein Atlas (HPA) and TIMER databases, we evaluated the protein expression levels of TGM3 in different organs and tissues as well as their association with immune cell infiltration and immunotherapeutic response in pan-cancers. Expression differences between normal and tumor tissues as well as survival and prognosis situation, clinical data characteristics, tumor mutational burden (TMB), microsatellite instability (MSI), and RNA methylation were also assessed. Oncogenic analyses were also evaluated by GSEA. Results: Compared to normal tissues, some tumor tissues had a lower expression level of TGM3, while other tumor tissues had a high expression level of TGM3. Further studies showed that high TGM3 expression had a certain risk impact on pan-cancer as high TGM3 expression levels were detrimental to the survival of several cancers, except for pancreatic cancer (PAAD). High expression level of TGM3 was also related to higher clinical stages in most cancers. The expression level of TGM3 was significantly negatively correlated with the expression of immune infiltration-related cells, including B cells, CD8+ T cells, CD4+ T cells, neutrophils, macrophages and dendritic cells (DCs). Furthermore, in most cancer types, TGM3 was inversely correlated with TMB, MSI, and methylation, suggesting that TGM3 expression can be used to assess potential therapeutic response, especially immune-related targeted therapy. GSEA analysis elucidated the biological and molecular function of TGM3 in various cancer types. Taken together, these bioinformatic analyses identified TGM3 as an important biomarker for clinical tumor prognosis and evaluation of treatment efficacy. Conclusion: We comprehensively analyzed the clinical characteristics, tumor stages, immune infiltration, methylation level, gene mutation, functional enrichment analysis and immunotherapeutic value of TGM3 in pan-cancer, providing implications for the function of TGM3 and its role in clinical treatment.
Hexavalent chromium is one of the main heavy metal pollutants. As the environmental legislation becomes increasingly strict, seeking new technology to treat wastewater containing hexavalent chromium is becoming more and more important. In this research, a novel modified ultrafiltration membrane that could be applied to adsorb and purify water containing hexavalent chromium, was prepared by polyvinylidene fluoride (PVDF) blending with 2-aminobenzothiazole via phase inversion. The membrane performance was characterized by evaluation of the instrument of membrane performance, infrared spectroscopy (FTIR), scanning electron microscope (SEM), and water contact angle measurements. The results showed that the pure water flux of the PVDF/2-aminobenzothiazole modified ultrafiltration membrane was 231.27 L/m²·h, the contact angle was 76.1°, and the adsorption capacity of chromium ion was 157.75 µg/cm². The PVDF/2-aminobenzothiazole modified ultrafiltration membrane presented better adsorption abilities for chromium ion than that of the traditional PVDF membrane.
Black carbon (BC) aerosol imposes adverse effects on atmospheric visibility, climate, and health. The particle density and morphology are often needed to investigate the mixing state and aging process of BC particles. A method, combining an aerodynamic aerosol classifier (AAC), a differential mobility analyzer (DMA), a single-particle soot photometer (SP2) and a single particle aerosol mass spectrometer (SPAMS), was developed to determine the density and dynamic shape factor (χ) of ambient BC particles with three different aerodynamic diameters (Da, 200 nm, 350 nm, and 500 nm) in Shanghai, China, a typical urban area. The BC particles were either classified as "BC-dominated particle" which is mainly made of black carbon or "BC-mixed particle" which is a mixture of both BC and non-BC substances. The results show that BC-dominated particles whose BC core mass (~2.2 fg) was almost equal to particle mass (~2.3 fg) were observed in particles with 200 nm Da. The morphology of these BC-dominated particles was near-spherical (χ ≈ 1.02), indicating that they had undergone rapid morphology modification from the initial highly irregular morphology to near-spherical shape. Most BC particles with 350 nm or 500 nm Da were BC-mixed particles. Combining the effective densities (1.62~1.77 g cm-3) and average single particle mass spectra of particle, the ammonium sulfate and ammonium nitrate were found to be the main secondary substances of these BC-mixed particles, indicating that condensation of inorganic species such as nitrates and sulfates could play a significant role in the aging process of fresh BC in Shanghai. Generally, the morphology and density information of single BC particle is crucial to identify the mixing state and aging process of BC aerosols.
In order to investigate the corrosion behavior of N80 steel in production wellbores of oxygen-reduced air drive, the main corrosion control factors are analyzed based on gray relational analysis. Taking reservoir simulation results as indoor simulation parameters, the corrosion behavior in different production periods is studied by the dynamic weight loss method combined with metallographic microscopy, XRD, 3D morphology, and other related characterizations. The results show that oxygen content is most sensitive to the corrosion of production wellbores. The corrosion rate increases significantly under oxygen-containing conditions, and the corrosion rate at an oxygen content of 3% (0.3 MPa) is about 5 times higher than that without oxygen. At the initial stage of oil displacement, the corrosion is CO2-dominated localized corrosion, and the corrosion products are mainly compact FeCO3. With the prolongation of gas injection time, the wellbore is in a CO2/O2 balanced environment, the corrosion changes into a combined action of the two, and the corrosion products are FeCO3 and loose porous Fe2O3. After continuous gas injection for 3 years, the production wellbore is in a high O2 and low CO2 environment, the dense FeCO3 is destroyed, the corrosion pit develops horizontally, and the corrosion changes to O2-dominated comprehensive corrosion.
Abstract. Dust is a major source of atmospheric aerosols. Its chemical composition is often assumed to be similar to the parent soil. However, this assumption has not been rigorously verified. Here, we generated dust aerosols from soils to determine if there is particle size-dependent selectivity of heavy metals in the dust generation. Mn, Cd, Pb and other heavy metals were found to be highly enriched in fine (PM2.5) dust aerosols, which can be up to ~6.5-fold. To calculate the contributions of dust to atmospheric heavy metals, regional air quality models usually use the dust chemical profiles from the US EPA’s SPECIATE database, which does not capture the correct size-dependent selectivity of heavy metals in dust aerosols. Our air quality modeling for China demonstrates that the calculated contribution of fine dust aerosols to atmospheric heavy metals, as well as their cancer risks, could have significant errors without using proper dust profiles.