Experimental Study on Subgrade Material of Calcium Silicate Slag

Calcium silicate slag (CSS) is used as a secondary solid waste produced by aluminum extraction technology from high alumina fly ash, and its resource utilization has always been a key issue to be solved. In this study, CSS was used to replace a portion of fly ash (FA) to prepare a new inorganic binder stabilized material for road base. The unconfined compressive strength (UCS), phase composition, microstructure, durability and performance index of the base of the test section of the CSS pavement base material were studied. The results showed that with the increase in CSS content, the UCS of pavement base materials gradually increased. Under standard curing conditions, the UCS increased 6.90~17.24% after 7 days, and 7.90~28.95% after 28 days. The main reason was that as the hydration time increased from 7 d to 28 d, the hydration products C-A-S-H gel and C-S-H gel increased, the [SiO₄] polymerization degree increased, the crystal type changed, and the structure denser, which supported the good development of mechanical strength of CSS pavement base material. In addition, the research has been successfully applied to a pilot test in Hohhot, China. The freeze–thaw resistance, water stability and UCS of the CSS pavement base material were tested to meet the requirements of Chinese road construction standards, indicating that the application of CSS in pavement base is feasible.     

Development of the Korea-Polyenvironmental Risk Score for Psychosis

Objective Comprehensive understanding of polyenvironmental risk factors for the development of psychosis is important. Based on a review of related evidence, we developed the Korea Polyenvironmental Risk Score (K-PERS) for psychosis. We investigated whether the K-PERS can differentiate patients with schizophrenia spectrum disorders (SSDs) from healthy controls (HCs). Methods We reviewed existing tools for measuring polyenvironmental risk factors for psychosis, including the Maudsley Environmental Risk Score (ERS), polyenviromic risk score (PERS), and Psychosis Polyrisk Score (PPS). Using odds ratios and relative risks for Western studies and the “population proportion” (PP) of risk factors for Korean data, we developed the K-PERS, and compared the scores thereon between patients with SSDs and HCs. In addition, correlation was performed between the K-PERS and Positive and Negative Syndrome Scale (PANSS). Results We first constructed the “K-PERS-I,” comprising five factors based on the PPS, and then the “K-PERS-II” comprising six factors based on the ERS. The instruments accurately predicted participants’ status (case vs. control). In addition, the K-PERS-I and -II scores exhibited significant negative correlations with the negative symptom factor score of the PANSS. Conclusion The K-PERS is the first comprehensive tool developed based on PP data obtained from Korean studies that measures polyenvironmental risk factors for psychosis. Using pilot data, the K-PERS predicted patient status (SSD vs. HC). Further research is warranted to examine the relationship of K-PERS scores with clinical outcomes of psychosis and schizophrenia.     

Effects of butylated hydroxyanisole on the development and functions of reproductive system in rats

Butylated hydroxyanisol (BHA) is a widely used antioxidant for long preservation of food products, cosmetics and pharmaceuticals. Although BHA is generally recognized as safe, it is classified as a suspected endocrine-disrupting compound. We investigated the effects of BHA on reproductive function and development by the treatment of mature male and female SD rats (F0) through pre-gestation, gestation and lactation period and of their offspring (F1) until 13 weeks old via gavage with BHA 0 (corn oil, vehicle control), 10, 100 and 500 mg/kg bw/day. Organ weights of liver, adrenal gland and thyroid gland of F0 rats were increased by BHA 500 mg/kg but those of spleen and ventral prostate were decreased without significant difference in terminal body weight. Reduced serum testosterone and thyroxine (T4) were observed with dose-dependent manner in F0 male rats. Mating rate was decreased and cohabitation duration for conception was longer without differences in the number, motility and morphology of sperm by BHA 500 mg/kg. Body weight of F1 offspring was significantly decreased with change of relative weight of liver and brain by BHA 500 mg/kg at PND21. Sexual maturation indicated by vaginal opening and preputial separation was delayed by BHA 500 mg/kg. The weights of liver and adrenal gland were increased while those of spleen, vagina, testes and ventral prostate were decreased in F1 rats exposed to BHA 100 or 500 mg/kg for 13 weeks. Also, BHA 500 mg/kg reduced the velocity of sperm motion and number with smaller-sized sperm head in F1 male rats and slightly shortened estrous cycle length with higher frequency of estrus and lower frequency of diestrus stages in F1 female rats. Lower serum T4 and testosterone contents with higher serum cholesterol levels were also observed by BHA 500 mg/kg. Increased follicular cell height, and exfoliated and vacuolated follicular epithelial cells were observed in thyroids of F1 female and males rats exposed to BHA 500 mg/kg. This study elucidates that high dose of BHA induce weak dysfunction and underdevelopment of reproductive system of male and female rats with the change of T4 and testosterone levels, sex organ weights and sexual maturation and histological lesions of thyroid gland.     

Outcome of Endodontic Micro-resurgery: A Retrospective Study Based on Propensity Score–matched Survival Analysis

Introduction

The purpose of this retrospective study was to evaluate and compare the outcome of endodontic micro-resurgery with that of primary endodontic microsurgery and determine prognostic factors affecting the outcome of micro-resurgery.

严重先天缺牙患者双侧双颧种植可行性的影像学评价

目的:探讨严重先天缺牙患者选择双侧双颧种植的可行性.方法:基于锥形束CT(cone-beamCT,CBCT)对21例严重先天缺牙患者行双侧双颧种植设计,测量虚拟植入的颧种植体在颧骨段影像学水平上的种植体-骨接触值(radiographic bone-to-implant contact,rBIC).采用SPSS 25....     

Prevalence of hyperuricemia and its associated factors in the general Korean population: an analysis of a population-based nationally representative sample

Clinical Rheumatology - Hyperuricemia is not only a risk factor for gout but also an independent determinant of hypertension, diabetes, and chronic kidney diseases. Although the incidence of gout...