Insight into coagulation/flocculation mechanisms on microalgae harvesting by ferric chloride and polyacrylamide in different growth phases.

FeCl3 and polyacrylamide (PAM) had been used to investigate the effect of coagulation, flocculation, and their combination on algae cells and extracellular organic matter (EOM) at different phases. PAM tended to aggregate particle-like substances, while FeCl3 could interact with EOM. The content of EOM kept rising during the algae growth cycle, while OD680 peaked at about 3.0. At stationary phase Ⅰ, the removal efficiencies of UV254, turbidity and OD680 of the suspension conditioned with FeCl3 + PAM reached (88.08 ± 0.89)%, (89.72 ± 0.36)% and (93.99 ± 0.05)%, respectively. Nevertheless, PAM + FeCl3 exhibited the worst efficiency because of the release of EOM caused by the turbulence. The results suggested that algal cells served as a coagulation aid to facilitate floc formation, while excessive EOM deteriorated harvesting performance. The process of FeCl3 + PAM at stationary phase Ⅰ appears to be a promising technology for microalgae harvesting.

Design Method and Teeth Contact Simulation of PEEK Involute Spline Couplings.

In order to design an involute spline made of PEEK (polyetheretherketone)-based material with better performance and improve the design rules of involute splines, initially, an involute splines design theory for PEEK (polyetheretherketone)-based materials is presented, which combines international standards (ISO 4156, 1. 2. 3, 2005), American standards (ANSI B92.2M. 1989), and traditional empirical formulas. Second, using the involute splines calibration method in international standards as a guide, we developed the involute splines calibration method for PEEK-based materials by estimating the impact of energy consumption caused by viscoelasticity on temperature field calibration. Next, the contact characteristics of the designed spline were analyzed using ABAQUS2022 software to confirm the accuracy and reliability of the design and calibration methods. Finally, finite element simulation was used to analyze the influence of different pressure angles, moduli, combined lengths, and other parameters on the contact characteristics of the spline in order to realize the optimal design of PEEK-based material involute splines, to offer a theoretical foundation and improved design methodology for cylindrical straight-tooth involute splines.

Single-Atom Molybdenum-N3 Sites for Selective Hydrogenation of CO2 to CO.

The design of efficient non-noble metal catalysts for CO2 hydrogenation to fuels and chemicals is desired yet remains a challenge. Herein, we report that single Mo atoms with a MoN3 (pyrrolic) moiety enable remarkable CO2 adsorption and hydrogenation to CO, as predicted by density functional theory studies and evidenced by a high and stable conversion of CO2 reaching about 30.4 % with a CO selectivity of almost 100 % at 500 °C and very low H2 partial pressure. Atomically dispersed MoN3 is calculated to facilitate CO2 activation and reduces CO2 to CO* via the direct dissociation path. Furthermore, the highest transition state energy in CO formation is 0.82 eV, which is substantially lower than that of CH4 formation (2.16 eV) and accounts for the dominant yield of CO. The enhanced catalytic performances of Mo/NC originate from facile CO desorption with the help of dispersed Mo on nitrogen-doped carbon (Mo/NC), and in the absence of Mo nanoparticles. The resulting catalyst preserves good stability without degradation of CO2 conversion rate even after 68 hours of continuous reaction. This finding provides a promising route for the construction of highly active, selective, and robust single-atom non-precious metal catalysts for reverse water-gas shift reaction.

PM2.5 mass concentration variation in urban residential buildings during heating season in severe cold region of China: A case study in Harbin.

Recent years, people pay great attention to fine particle matter (PM2.5) in indoor environment due to its negative impacts on health. Household cooking and severe air pollutant aggravate indoor PM2.5 level, especially during heating season in severe cold region of China. To find the variation of actual household PM2.5 influenced by both cooking activities and penetration from outdoor environment, a field measurement of PM2.5 concentrations in living room of residential buildings was conducted in Harbin, China. Firstly, six households in urban residence were selected to monitor the indoor PM2.5 mass concentration sequentially. Simultaneously, outdoor PM2.5 concentrations, temperature and indoor occupants' behavior were collected. Secondly, indoor to outdoor (I/O) ratios of PM2.5 in each household during monitoring campaigns were calculated. Influence of cooking activities and outdoor penetration on indoor PM2.5 concentrations in living room were also analyzed. Thirdly, some discussions were done for explanation of variation of PM2.5 in urban residential buildings. Results showed that the average PM2.5 mass concentrations varied from 11.7 to 48.6 µg/m3 indoor, while average I/O ratio value ranged from 0.33 to 1.23. Cooking in kitchen had significant impact on PM2.5 mass concentrations in living room, especially when frying, which could lead to peak value of 456.8 µg/m3 within 10 min from background level. Penetration led to the indoor PM2.5 level approximately 2 h behind with outdoor PM2.5 concentrations in general residences.

Downregulation of miR­136­5p in hepatocellular carcinoma and its clinicopathological significance.

The clinical significance of microRNA (miR)­136­5p in hepatocellular carcinoma (HCC) has not been verified. Therefore, in the current study, the authors aimed to explore miR­136­5p expression and its clinical significance in HCC, as well as to investigate its potential target genes function. The authors detected the levels of miR­136­5p in 101 pairs of HCC and para­cancer tissues via reverse transcription­quantitative polymerase chain reaction. Gene Expression Omnibus database and the Cancer Genome Atlas (TCGA) database were used to further verify the clinical significance of miR­136­5p expression in HCC. The target genes prediction analysis of miR­136­5p, natural language processing (NLP) analysis of HCC in PubMed and gene functional enrichment analysis were conducted. The miR­136­5p level was markedly downregulated in HCC tissue, compared to para­non­tumor tissue. MiR­136­5p expression decreased in HCC patients with metastasis (P=0.004), advance TNM stage (P<0.001), portal vein tumor embolus (P=0.007) and vaso­invasion (P=0.003), compared with those HCC patients with non­metastasis, early TNM stage, non­portal vein tumor embolus and non­vaso­invasion, respectively. In the TCGA database, downregulated miR­136­5p was also observed in HCC tissue compared to normal liver tissue (P<0.001). There were 178 genes obtained from the overlap between predicted targets and NLP analysis. GO and KEGG pathway analyses revealed some significant pathways related to cancers. Downregulation of miR­136­5p may be responsible for the carcinogenesis and aggressiveness of HCC. miR­136­5p may act as an anti­carcinoma miRNA, which is essential for HCC progression through the regulation of various signaling pathways. Thus, miR­136­5p interaction may provide a novel strategy for HCC treatment.

Overexpression and clinicopathological contribution of DcR3 in bladder urothelial carcinoma tissues.

BACKGROUND: To explore the expression of DcR3 protein and its clinicopathological significance in bladder urothelial carcinomas (BUC). MATERIALS AND METHODS: Immunohistochemistry was performed to detect the expression of DcR3, caspase-3, Bcl-2, VEGF, Ki-67, PCNA and P53 in 166 BUC and 56 normal bladder tissues. Western blotting was used to detect the expression of DcR3 in the supernatants of cultured BUC cells. RESULTS: Overexpression of DcR3 was found in BUC tissues and cell lines, with significant elevation as compared to normal bladder tissues (p<0.0001). Higher DcR3 expression was related to the status of invasion, lymph node metastasis and recurrence. Furthermore, DcR3 expression was negatively correlated with caspase-3 and positively associated with Bcl-2, VEGF, Ki-67 labeling index (LI), PCNA LI and P53 (all p<0.0001), respectively. CONCLUSIONS: DcR3 may play a crucial role as an oncogene in tumorigenesis, deterioration and progress of BUC via influencing related pathways of apoptosis, proliferation and angiogenesis. The detection of DcR3 protein in the formalin- fixed and paraffin-embedded samples could assist to predict in prognosis of BUC patients.