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Background. This retrospective study is aimed at (I) assessment of tooth loss and related parameters after jaw curettage of benign lesions and (II) assessment of the outcome of jaw curettage supported by splint insertion after at least six months of follow-up. Material and Methods. For (I), patients who had jaw curettage surgery in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University (Guangzhou, China) from July 2015 to June 2019 were included. For part (II), consecutive patients who came to the department from July to December 2019 that were additionally treated with dental splinting were involved in this study. Based on the patient records, age, gender, initial tooth mobility, follow-up outcome, and potential tooth loss (intra- or postoperatively) were recorded. Based on available radiographs, alveolar crest bone loss and root surface area supported by bone (RSA) were determined. Results. (I) 128 patients with 305 teeth were included, of which 40 teeth were lost (success rate 86.9%), without statistical difference in gender, age, or tooth type ( P > 0.05 ). Tooth mobility, RSA, and the presence of alveolar crest bone defects were associated to tooth loss ( P < 0.001 ). (II) 17 patients with a medium follow-up period of 11 months (range 9 to 13 months) were enrolled. All lesion-involving teeth supported by splint treatment at risks of loss were preserved, showing an effective tooth retention rate in 17/17 cases (74/74 teeth, success rate: 100%). Conclusions. Tooth mobility and bone loss (lesion-related and/or periodontal) are potential risk predictors for tooth loss in the first year after jaw curettage surgery. Dental splints could be recommendable for teeth involved by jaw benign lesions with little bone support.

Selective laser melting (SLM) Ti-6Al-4V has been used for removable partial dentures, but the impact of SLM Ti-6Al-4V build orientation is not evident.The purpose of this in vitro study was to investigate the microstructure and properties of SLM Ti-6Al-4V clasps with different build orientations compared with cast Ti-6Al-4V clasps.Forty-eight clasps were made from Ti-6Al-4V alloys-by SLM with 3 different build orientations (SLM0, SLM45, and SLM90) and cast (CAST) as a control. The microstructure was investigated by using a metallographic microscope and a confocal laser scanning microscope. The fit and surface roughness of the clasps were measured, and the physical properties were evaluated. In addition, the von Mises stresses in the clasps were calculated by finite element analysis. All specimens were then subjected to insertion and removal tests in artificial saliva to model 5 years of clinical use. After these tests, 3-point bend tests were used to analyze the fracture surface of the clasp arms, which were observed by using a scanning electron microscope. All data were statistically analyzed (α=.05).The microstructure of the Ti-6Al-4V specimens was a comixture of α+β phases. In addition, growth directions of β grains were approximately parallel to the build orientation, with acicular α grains present between β grains. SLM0 and SLM45 had significantly higher roughness than SLM90. Even though the fit was inferior to that of SLM90, SLM0 and SLM45 still performed better than cast specimens (P.05). The finite element analysis showed that the maximum von Mises stress was located on the middle part of the retainer arms and that the values of the 0.50-mm undercut clasps were much lower than the elastic limit. In addition, the decrease of retentive force in SLM90 clasps was less than that of the CAST group (P.05). CAST clasps showed brittle fracture, whereas all SLM clasps showed ductile fracture.The microstructure of SLM Ti-6Al-4V affected the properties of clasps by changing the anisotropy of specimens. Among the tested groups, SLM90 clasps had the best fit, the lowest surface roughness, and the best fatigue resistance. Furthermore, SLM Ti-6Al-4V clasps could be engaged into 0.50-mm undercuts.

Removal of toxic polychlorinated aromatic hydrocarbons (PCAHs) with cheap, efficient, and environmentally friendly catalysts has long been considered a challenging issue. We synthesized novel catalysts which were made from CaCO 3 /Fe 2 O 3 nanorods. These catalysts oxidized PCAHs and were characterized using numerous analytical techniques. The catalytic activity was evaluated using 1,2-dichlorobenzene ( o -DCB), as a model PCAH compound. The results demonstrated that the catalyst (FeCa3) with 2.8 mol% Ca-doping shows superior catalytic activity, with the complete o -DCB oxidization at a lower temperature (350 °C) than other reported CaCO 3 /α-Fe 2 O 3 nanocomposites (450 °C). Also, we demonstrated that the catalytic activity and stability increased in the presence of water vapor which differs from previous studies. We attribute the excellent catalytic activity to the unique surface morphology and interfacial microstructure composed of CaCO 3 and α-Fe 2 O 3 nanorods, which play a crucial role in enhancing catalytic activity and stability in a humid atmosphere. The intermediates (formate, acetate, and maleate) and final products (CO 2 and H 2 O) were monitored by in situ FTIR spectroscopy. In summary, we demonstrated that our CaCO 3 /Fe 2 O 3 nanorod catalysts are promising catalysts for the oxidation of PCAHs.

The influence of different levels of heat exposure on the functions of ovarian and adrenal gland were investigated in pre-puberty female rats. Three-week old female rats were treated with control (26°C) or three higher temperatures (38, 40 and 42°C) for 2hr/day. After 9 days of treatment, blood samples were collected for measurement of luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol-17β, corticosterone, cholesterol and triglyceride. Adrenal glands, ovaries and liver were collected for analyzing gene expressions. Body and liver weight were significantly low in the 42°C heating group. Circulating LH and triglyceride in the 42°C heating group were significantly lower, and estradiol-17β, corticosterone and cholesterol were significantly higher than those of the control group. The gene expression of 3β-HSD and P450c21 in the adrenal gland; 3β-HSD, receptors of LH, FSH and estrogen in the ovary were significantly low in heated rats. The liver gene expressions of caspase 3 and NK-κB were significantly high in 42°C heated rats, suggesting that the ability of liver metabolic function reduced in the 42°C heated rats. These results demonstrated that the high temperature is responsible for suppression of ovarian function by decreasing the expression of steroidogenic enzymes, estrogen and gonadotropin receptors in the ovary. Increase in circulating estradiol-17β in the heated rats may be due to accumulate this hormone in circulation by potential changes in liver metabolism during the heat stress.

The present study was designed to investigate the effect of hydrogen sulfide on cellular senescence of human umbilical vascular endothelial cells (HUVECs CC-2517) and its underlying mechanism. The premature senescence-like phenotype HUVECs (the fourth passage) was induced by treatment with nicotinamide (NAM, an inhibitor of SIRT1, 5 mmol/L, 12 h). Cells were cultured with sodium hydrosulfide (NaHS, 12.5, 25, 50 and 100 μmol/L) for 48 h in premature senescence-like phenotype HUVECs. The fourth passage of HUVECs was considered as young group. Senescence-associated (SA)-β-galactosidase activities were detected to evaluate cell senescence, and the expression of SA heterochromatin foci (SAHF) was visualized by DAPI DNA staining. The mRNA and protein levels of SIRT1 were detected using RT-PCR and western blotting analysis, respectively. The results showed that β-galactosidase positive cells and the formation of SAHF were markedly increased after treatment with NAM (5 mmol/L) for 12 h. We also found that NaHS (12.5 μmol/L) had no effect on the percentage of SA β-gal positive cells and the expression of SAHF, and the hallmarks decreased at the concentration of 25 and 50 μmol/L, reaching the minimum at 50 μmol/L, while the percentage of SA β-gal positive cells and the expression of SAHF increased at the concentration of 100 μmol/L. Furthermore, we found that both on protein and mRNA levels of SIRT1 in the Y+N+S50 group was significantly increased compared with that in Y+N group. In conclusion, NaHS delays senescence of HUVECs induced by NAM via upregulation of SIRT1 expression.

Novel Ca-doped FeOx hollow microspheres were successfully prepared using carbon microspheres as templates. The as-prepared catalysts were characterized by FAAS, XRD, N2 adsorption/desorption, SEM, TEM, H2-TPR and XPS. The catalytic activities of the samples were evaluated by catalytic oxidation of 1,2-dichlorobenzene (o-DCB). The results showed that the molar ratios of Ca/(Ca + Fe) in the hollow microspheres and their morphologies significantly affected their catalytic performances. The low-temperature catalytic activity decreased in the order of FeCa10 > FeCa20 > Fe2O3 > FeCa5, in well agreement with the sequence of their reducibility. The optimal FeCa10 catalyst exhibited not only excellent catalytic activity, water-resistant performance and stability but also lower apparent activation energy (21.6 kJ/mol). In situ FTIR measurements revealed the acetate and formate species were the partial oxidation products, which could be subsequently oxidized to form CO2. It is concluded that the excellent catalytic performance of FeCa10 catalyst might be attributed to the combined effects of several factors such as small crystallite size, high surface active oxygen concentration, good low-temperature reducibility and the synergic effect between CaO and Fe3O4. It is reasonable for us to believe that such Ca-doped FeOx hollow microspheres are promising catalysts for the elimination of chlorinated volatile organic pollutants.

Ti-doped iron oxides with worm-like mesopores were successfully prepared using CTAB as the structure-directing agent. The as-prepared catalysts were characterized by XRD, Raman, H2-TPR, XPS, TEM, and N2 adsorption/desorption. The catalytic properties for oxidation of 1,2-dichlorobenzene (o-DCB) were investigated. The results showed that Fe18Ti2Ox with 10 mol% Ti-doping shows the best catalytic activity, and the total conversion of o-DCB can be obtained at 350 °C. Moreover, Fe18Ti2Ox exhibits higher stability, CO2 selectivity and lower apparent activation energy. The high activity of Fe18Ti2Ox could be ascribed to the combined factors including a smaller crystallite size, excellent low-temperature reducibility, high surface active oxygen concentration and a synergic effect between TiO2 and mixed iron oxide (γ-Fe2O3 and α-Fe2O3). Acetate and formate species as intermediates were detected by in situ FTIR spectroscopy. A two-step redox mechanism of o-DCB decomposition on the surface of Ti-doped iron oxides was proposed. These results demonstrated that Ti-doped iron oxides could be developed as environmentally friendly catalysts for the deep oxidation of chlorinated volatile organic pollutants.