Search

The fragmented and complex topography of mountainous plateau basins resulted in significant regional differences at the watershed scale in soil physicochemical properties, soil texture and soil types, etc. Due to the large watershed range, high altitude, and high sampling difficulty, there was relatively little research on the background values of soil environment in mountainous plateau areas. The purpose of this study was to determine the environmental background values of soil and explore the main environmental controls for the Bijiang Basin in Southwest China. The environmental background value of soil Pb and Zn in the Bijiang River Basin was 30.73 mg·kg-1 and 64.85 mg·kg-1, respectively. The value was mainly affected by altitude, soil type, pH and organic matter. The research results had certain reference value for the selection of background values for regional pollution assessment on soil or sediment in mountainous areas. [ABSTRACT FROM AUTHOR]

In this paper, a nanosecond laser was used to etch the surface of graphene nanoplatelets reinforced ZK60 (GNPs/ZK60) matrix composites, and the effects of different scanning speeds, pulse repetition frequency and laser power on the etched morphology of the machined surface were investigated. The experimental results show that the etched groove width and heat affected zone width of GNPs/ZK60 composites are significantly increased compared with ZK60 material due to the influence of graphene, and the growth rate of the difference in heat affected zone width between GNPs/ZK60 composites and ZK60 materials is most significantly affected by the pulse repetition frequency. In addition, the dross height increases with the increase of laser power, while the scaly dross structure becomes increasingly clear. [ABSTRACT FROM AUTHOR]

The multi-markers combined detection can make up for the deficiency of single marker detection and significantly increase the positive detection rates of tumors. This study aimed to assess the performance of serum HER-2 extracellular domain (HER-2/neu ECD), carcinoembryonic antigen (CEA), and cancer antigen 15-3 (CA15-3) in early screening and auxiliary diagnosis of breast cancer. The HER-2, CEA, and CA15-3 serum levels were measured in 164 healthy volunteers, 111 patients with benign nodules (BN), 123 with early breast cancer (EBC), and 25 with advanced breast cancer. In distinguishing health and EBC, the sensitivity and specificity of joint detection of HER-2, CEA, and CA15-3 were 96.75% and 96.95%, respectively; the accuracy was up to 96.19%, and the AUC was 0.994. In the cohort for distinguishing BN from EBC, serum HER-2, CEA, and CA15-3 sensitivities were 77.03%, 75.27%, and 48.65%, respectively. Combined with three markers, the sensitivity was increased to 84.46%, the AUC was 0.834. All in all, through the combined detection of serum HER-2, CEA and CA15-3 levels in healthy volunteers, BN and EBC, our study found that this method can significantly improve the diagnosis level of breast cancer, suggesting that the three markers panel can be used as an effective tool to improve the early screening level, early diagnosis, and clinical intervention of breast cancer. [ABSTRACT FROM AUTHOR]

OBJECTIVE: It is difficult to conclude that COVID-19 is associated with a decrease in the suicide attempts rate by comparing only a short-term period. Therefore, it is necessary to examine attempted suicide rates through a trend analysis over a longer period. This study aimed to investigate an estimated long-term trend regarding the prevalence of suicide-related behaviors among adolescents in South Korea from 2005 to 2020, including COVID-19. SUBJECTS AND METHODS: We sourced data from a national representative survey (Korea Youth Risk Behavior Survey) and analyzed one million Korean adolescents aged 13 to 18 years (n=1,057,885) from 2005 to 2020. The 16-year trends regarding the prevalence of sadness or despair and suicidal ideation and attempt and the trend changes before and during COVID-19. RESULTS: Data of 1,057,885 Korean adolescents was analyzed (weighted mean age, 15.03 years; males, 52.5%; females, 47.5%). Although the 16-year trend in the prevalence of sadness or despair and suicide ideation and attempt consistently decreased (prevalence of sadness or despair between 2005-2008, 38.0% with 95% confidence interval [CI], 37.7 to 38.4 vs. prevalence in 2020, 25.0% [24.5 to 25.6]; suicide ideation between 2005-2008, 21.9% [21.6 to 22.1] vs. prevalence in 2020, 10.7% [10.3 to 11.1]; and suicide attempt between 2005-2008, 5.0% [4.9 to 5.2] vs. prevalence in 2020, 1.9% [1.8 to 2.0]), the downward slope decreased during COVID-19 (ßdiff in sadness, 0.215 with 95% CI 0.206 to 0.224; ßdiff in suicidal ideation, 0.245 [0.234 to 0.256]; and ßdiff in suicide attempt, 0.219 [0.201 to 0.237]) compared with pre-pandemic period. CONCLUSIONS: This study found that the observed risk of suicide-related behaviors during the pandemic was higher than expected through long-term trend analysis of the prevalence of sadness/despair and suicidal ideation and attempts among South Korean adolescents. We need a profound epidemiologic study of the change in mental health due to the pandemic's impact and the establishment of prevention strategies for suicide ideation and attempt. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The impact of the coronavirus disease 2019 (COVID-19) pandemic on weight gain in children and adolescents remains unknown. We aimed to identify an estimated 15-year trend in mean body mass index (BMI) changes and prevalence of obesity and overweight among Korean adolescents from 2005 to 2020, including the period of the COVID-19 pandemic. PATIENTS AND METHODS: We analyzed data taken from a nationwide survey (Korea Youth Risk Behavior Survey), between 2005 and 2020. Representative samples of one million Korean adolescents aged 13-18 years (n=1,057,885) were examined. The 15-year trends in mean BMI and proportion of obesity or overweight, and the changes due to the COVID-19 pandemic were analyzed. RESULTS: The data of 1,057,885 Korean adolescents were analyzed (mean age: 14.98 years; females, 48.4%). The estimated weighted mean BMI was 20.5 kg/m² [95% confidence interval (CI), 20.4-20.5] from 2005 to 2008 and 21.5 kg/m² (95% CI, 21.4-21.6) in 2020 (during the COVID-19 pandemic). Although the 15-year trend of mean BMI gradually increased, the change in mean BMI before and during the pandemic significantly lessened (βdiff, -0.027; 95% CI, -0.028 to -0.026). The 15-year (2005-2020) trend changes in the prevalence of obesity and overweight were similar (obesity prevalence from 2005-2008, 3.2%; 95% CI, 3.1-3.3 vs. obesity prevalence in 2020, 8.6%; 95% CI, 8.2-9.0; βdiff, -0.309; 95% CI, -0.330 to -0.288). CONCLUSIONS: The 15-year trend of overall mean BMI and obesity and overweight prevalence demonstrated a significant increase; however, its slope decreased during the pandemic. These landmark results suggest the need for the development of precise strategies to prevent pediatric obesity and overweight during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The optimal remifentanil concentration for improving intubation conditions when intubation is performed without neuromuscular blocking agents (NMBAs) but with ketamine as an induction agent remains unknown. Here, we aimed to identify the effective bolus doses of remifentanil required to achieve acceptable intubation conditions upon anesthesia induction with 1 or 2 mg/kg ketamine without NMBAs PATIENTS AND METHODS: In this prospective, double-blinded, randomized up-down sequential allocation study, we enrolled pediatric patients aged 3-12 years undergoing general anesthesia for inguinal hernia surgery. The patients were randomly allocated to one of two groups to receive either ketamine 1.0 mg/kg (K1 group) or 2.0 mg/kg (K2 group) intravenously until seven success-failure pairs were achieved. The remifentanil dose for each patient was determined using the modified Dixon's up-anddown method with an initial dose of 2.5 µg/kg and a step size of 0.5 µg/kg. RESULTS: In total, 51 patients (22 in the K1 group and 29 in the K2 group) were enrolled. The effective dose (ED)50s of remifentanil for obtaining clinically acceptable intubation conditions under anesthesia induction with ketamine but without NMBAs was 3.2 µg/kg in the K1 group and 1.6 µg/kg in the K2 group. Highdose remifentanil with 1 mg/kg ketamine was associated with more severe chest wall rigidity and lower mean blood pressure and heart rate than was low-dose remifentanil with 2 mg/kg ketamine. CONCLUSIONS: The ED50 of remifentanil required for clinically acceptable intubation conditions with anesthesia induction using 1 mg/kg ketamine without NMBAs in pediatric patients was twice that when using 2 mg/kg ketamine. The combination of 2 mg/kg ketamine and remifentanil was better at preventing chest wall rigidity. [ABSTRACT FROM AUTHOR]