Design and preparation of Ti-xFe antibacterial titanium alloys based on micro-area potential difference.

Fe was selected as an alloying element for the first time to prepare a new antibacterial titanium alloy based on micro-area potential difference (MAPD) antibacterial mechanism. The microstructure, the corrosion resistance, the mechanical properties, the antibacterial properties and the cell biocompatibility have been investigated in detail by optical microscopy, scanning electron microscopy, electrochemical testing, mechanical property test, plate count method and cell toxicity measurement. It was demonstrated that heat treatment had a significant on the compressive mechanical properties and the antibacterial properties. Ti-xFe (x = 3,5 and 9) alloys after 850 °C/3 h + 550 °C/62 h heat treatment exhibited strong antimicrobial properties with an antibacterial rate of more than 90% due to the MAPD caused by the redistribution of Fe element during the aging process. In addition, the Fe content and the heat treatment process had a significant influence on the mechanical properties of Ti-xFe alloy but had nearly no effect on the corrosion resistance. All Ti-xFe alloys showed non-toxicity to the MC3T3 cell line in comparison with cp-Ti, indicating that the microzone potential difference had no adverse effect on the corrosion resistance, cell proliferation, adhesion, and spreading. Strong antibacterial properties, good cell compatibility and good corrosion resistance demonstrated that Ti-xFe alloy might be a candidate titanium alloy for medical applications.

Cytotoxicity and toxicoproteomic analyses of human lung epithelial cells exposed to extracts of atmospheric particulate matters on PTFE filters using acetone and water.

Differences of cytotoxicity associated with exposure to different extracts of atmospheric particulate matters (PMs) are still not well characterized by in vitro toxicoproteomics. In this study, in vitro cytotoxicity assays and toxicoproteomic analyses were carried out to investigate toxic effects of PM collected using polytetrafluoroethylene (PTFE) filters extracted with acetone for PM2.1 and water for PM2.1 and PM10 on A549 human lung epithelial cells. The cytotoxicity assays based on cell viability, cell apoptosis and reactive oxygen species generation indicated that PM2.1 extracted with acetone had the highest toxicity. iTRAQ labeling and LC-MS/MS analyses indicated that the number of differentially expressed proteins in A549 cells affected by PM2.1 extracted with acetone was noticeably higher than that of the other two groups. Hierarchical cluster analyses showed that the influences of the extracts of PM2.1 and PM10 using water on the proteome of A549 cells were similar, whereas significantly different from the effect of PM2.1 extracted with acetone. Pathways analyses indicated that PM2.1 extracted with acetone influenced the expression of proteins involved in 14 pathways including glycolysis/gluconeogenesis, pentose phosphate pathway, proteasome, etc. PM2.1 extracted with water affected the expression of proteins involved in 3 pathways including non-homologous end-joining, ribosome and endocytosis. However, PM10 extracted with water affected the expression of proteins involved in only spliceosome pathway. The extracts of PM using different extractants to detach PM from PTFE filters influenced the cytotoxic effects of PM and the proteome of A549 cells. Therefore, extractants should be assessed carefully before the investigations on cytotoxicity to improve the compatibility of experimental results among research teams.

Quantitative comparison of the delignification performance of lignocellulosic biomass pretreatment technologies for enzymatic saccharification.

Pretreatments for delignification are required for the enzymatic saccharification of lignocellulosic biomasses. However, in the current literature, various pretreatment approaches have been applied for the same kinds of biomass. To find the optimum pretreatments for biomaterials containing various lignin contents, in this study, a quantitative comparison was carried out on the delignification performance of 15 categories of pretreatments. In total, 1729 sets of biomass, cellulose, hemicellulose, and lignin recovery data were collected from 214 relevant studies. Box plots and Cate-Nelson-like graphs were applied for analyses. The results showed that alkali, oxidation, organic solvent, and multistep pretreatments generally were better at removing lignin and recovering cellulose. Moreover, among these four categories, alkali pretreatments had the best performance, increasing the saccharification efficiency by approximately five-fold. Considering both delignification performance and saccharification improvement, alkali pretreatments are currently considered to be the optimum pretreatment methods for enzymatic saccharification.

Comparison of dental pulp periodontal therapy and conventional simple periodontal therapy as treatment modalities for severe periodontitis.

BACKGROUND: Severe periodontitis is a major oral health concern today as it can lead to loss of teeth. Conventional periodontal therapy has numerous pitfalls as it does not address the pulp-periodontal complex in its entirety. AIM: To investigate the effect of dental pulp periodontal therapy on the levels of interleukin-1ß (IL-1ß) and IL-10 in gingival crevicular fluid (GCF) in patients with severe periodontitis. METHODS: Eighty-six patients with severe periodontitis were randomly divided into a research group (n = 43) and a control group (n = 43). The control group was treated with simple periodontal therapy, and the research group was treated with dental pulp periodontal therapy. The total effective rates of the treatments; periodontal status before and after treatment through the measurement of the periodontal pocket probing depth (PPD), gingival sulcus bleeding index (SBI), mobility (MD), and plaque index (PLI); the levels of inflammatory factors IL-1ß and IL-10 in the GCF; and the incidence of complications were calculated for both groups and compared using the Student's t test and the χ 2 test. RESULTS: The total effective rate of treatment in the study group (93.02%) was higher than that in the control group (76.74%; P < 0.05). While before treatment, there was no significant difference in the PLI, MD, SBI, or PPD between the two groups, the post-treatment values of PLI, MD, SBI, and PPD (4.71 ± 0.16 mm, 0.61 ± 0.09 mm, 0.96 ± 0.17 mm, and 0.76 ± 0.26 mm, respectively) were significantly lower (P < 0.05) in the research group than in the control group (5.35 ± 0.24 mm, 0.93 ± 0.15 mm, 1.35 ± 0.30 mm, and 1.04 ± 0.41 mm, respectively). There was no significant difference in the level of IL-1ß or IL-10 in the GCF before treatment between the two groups; after treatment, the IL-1ß level in the research group (139.04 ± 15.54 pg/mL) was significantly lower than that in the control group (156.35 ± 18.10 pg/mL), and the level of IL-10 in the research group (7.98 ± 1.01 ug/L) was higher than that in the control group (5.56 ± 0.96 ug/L) (P < 0.05). The incidence of complications in the study group (4.65%) was significantly lower than that of the control group (18.60%; P < 0.05). CONCLUSION: Endodontic therapy and periodontal treatment for patients with severe periodontitis can effectively reduce the levels of inflammatory factors in the GCF and the inflammatory reaction. In addition, it can improve the periodontal condition and the overall treatment effect, reduce the risk of complications, and ensure the safety of treatment.

Estimation of soil microplastic input derived from plastic gauze using a simplified model.

Plastic gauzes have been widely used in the BTH region against haze events and for agricultural practices. The breakage of plastic gauzes would lead to the release of microplastics into soils, but it is difficult to estimate the inputs due to their wide implementation. In this study, we have conducted an estimation model based on the remote sensing technology for plastic gauze identification and the data from field experiments and literature. This model first managed to interpret the distribution of plastic gauzes from the Landsat8 images with the average overall accuracy at 0.92 and the average kappa at 0.77. By deeming the implementation duration of plastic gauzes from their distribution and using the breakage rates of plastic materials in soils reported in the literature, the model estimated that on average 1629.68 tons of microplastics have been released to soils from plastic gauze annually in the BTH region. Comparing with the microplastics released from other sources (e.g., personal care products, household dusts, laundry, and tire wear), plastic gauze could be a considerable contributor to soil microplastics.

An overview of alginates as flame-retardant materials: Pyrolysis behaviors, flame retardancy, and applications.

Alginates, a kind of naturally occurring polysaccharides, have been exploited for functional materials owing to their versatility, sustainability, nontoxicity, and relatively low cost. Inherent flame retardancy is one of the most attractive features of alginates, as it enables the high-value-added utilization of alginates for eco-friendly flame-retardant materials. Now, the influence of metal ions on the flame retardancy and pyrolysis behaviors of alginates has been systematically studied; besides, the applications of alginates for flame-retardant materials have been greatly developed, such as for preparing flame-retardant fibers, fabrics, aerogel composites, and foams, as well as serving as a component or modifier of functional coatings, hybrids, and additives. This review will give an overview of the recent progress and the prospects of using alginates in flame-retardant fields, which can guide the design of bio-based flame retardants and benefit the further development of more diverse applications of alginates.

[Radiographic study of the age for crown and root length completion stages of permanent teeth in male and female children].

PURPOSE: To determine the age medians for crown and root length completion stages of permanent teeth (except for the third molars) and to study gender differences in crown and root length completion stages by radiographic examinations. METHODS: The development of permanent teeth (except for the third molars) was evaluated from 3304 panoramic radiographs of children aged between 3 and 18 years by Haavikko's method. Statistical analysis was performed using SPSS 25.0 software package. Age medians for crown and root length completion stages of permanent teeth were calculated. Gender differences were analyzed by Mann-Whitney U test. RESULTS: There were no significant gender differences in crown completion stages of central incisor and first molar, of which P values were 0.143 (for maxillary central incisor), 0.122 (for maxillary first molar), 0.191 (for mandibular central incisor) and 0.558 (for mandibular first molar), while girls were found to be ahead of boys for crown completion stages of other teeth. In maxilla, girls were found to be ahead of boys for root length completion stages except for lateral incisor, second premolar and second molar, of which P values were 0.057, 0.130 and 0.294; in mandible, except for second premolar and second molar, girls were observed to be ahead of boys for root length completion stages, of which P values were 0.428 and 0.057. CONCLUSIONS: It is concluded that girls are advanced than boys for crown and root length completion stages in most teeth. There is a similarity in gender differences for crown and root length completion stages between maxilla and mandible.

Ultravilolet-radiation-induced graft polymerization of acrylamide onto the melt-blown polypropylene filter element by dynamic method.

By dynamic method under UV irradiation, commercial melt-blown polypropylene (PPMB) filter element was modified with acrylamide (AAm) using benzophenone (BP) as initiator. Attenuated total reflection-Fourier transform infrared spectroscopy and scanning electron microscope verified that polyacrylamide chain was grafted on the fiber surface of PPMB filter element. Elemental content analysis with energy dispersive X-ray of fibers revealed that the polymerization content in the inner part of filter element was relatively higher than that in the outer. Degree of grafting changed with initiator concentration, monomer concentration, reaction temperature and reached 2.6% at the reaction condition: CBP=0.06 mol/L, CAAm=2.0 mol/L, irradiation time: 80 min, temperature: 600 degrees C. Relative water flux altered with the hydrophilicity and pore size of filter element. In the antifouling test, the modified filter gave greater flux recovery (approximately 70%) after filtration of the water extract of Liuweidihuang, suggesting that the fouling layer was more easily reversible due to the hydrophilic nature of the modified filter.