Factors Associated with the Health Literacy on Social Determinants of Health: A Focus on Socioeconomic Position and Work Environment.

Though impressive progress has been made in healthcare worldwide, many people still experience disproportionate health burdens and inequities in healthcare services. For establishing sustainable development goals, health literacy on social determinants of health (HL-SDH) has been recognized as a key to creating better social and physical environments. In particular, low levels of health literacy among industrial workers are considered as a major barrier to benefitting from the progress made in healthcare. This study aimed to describe levels of HL-SDH and to examine the relationships among socioeconomic status, working environment, and HL-SDH among workers in Korea. A total of 660 workers from an online panel participated in Korea from 30 May to 7 June 2018. The Korean version of HL-SDH instrument consisted of 33 items and four dimensions: access, understand, appraise, and apply. Descriptive statistics, a t-test, ANOVA, and multiple regression analysis were conducted. The mean score of HL-SDH was 2.48. Perceived mental health status, annual income, and the number of employees per worksite were found to be statistically significant factors related to HL-SDH (F = 3.64, p = <0.001). The HL-SDH score was considerably higher, indicating that nursing interventions to enhance HL-SDH are required for health promotion, especially among workers in poor social and working environments.

Advanced treatment of gamma irradiation induced livestock manure using bioelectrochemical ion-exchange reactor.

Organic matter and nitrogen in livestock manure was pre-treated by gamma irradiation. The optimal dose ranged 30-50 kGy for solubilization of organic matter and nitrogen. Carbohydrates and proteins increased with the applied dose. Lipids did not show a regular increase pattern. A large amount of organic nitrogen in livestock manure was solubilized after gamma irradiation. The pre-treated livestock manure was treated using a bioelectrochemical ion-exchange reactor. High removal of organic matter and nitrogen was achieved with the applied dose of 50 kGy. The maximum 88.5% of chemical oxygen demand removal was obtained in the bioelectrochemical ion-exchange reactor due to readily biodegradable chemical oxygen demand fraction. Nitrogen removal was significantly affected by ammonia flux of ion-exchange membrane between anaerobic and aerobic chamber. With a high ammonia flux of 4.7513 mg/m2/sec, the maximum ammonia removal was 79.1%.

Removal of organic matter and nitrogen in swine wastewater using an integrated ion exchange and bioelectrochemical system.

Swine wastewater was treated using an integrated ion exchange and bioelectrochemical system. This system contains three chambers separated by a cation exchange membrane (CEM) and an anion exchange membrane (AEM). Each chamber acted as a bioanode chamber, an aerated biocathode chamber, and a denitrification chamber. To accelerate the ammonium transportation through CEM, a bioelectrochemical system was installed between bioanode and aerated biocathode. The current was provided by a programmable DC power supply. The average chemical oxygen demand (COD) removal efficiencies at applied voltages of 0, 1 and 3 V were 65.6%, 75.4% and 80.6%, respectively. Unlike the COD removal, the total nitrogen removal was proportional to the ammonium flux through the CEM. The average total nitrogen removal efficiencies at the applied voltages of 0, 1 and 3 V were 37.0%, 63.1% and 70.5%, respectively.

Characterization of modified PVDF membrane by gamma irradiation for non-potable water reuse.

Poly(vinylidene fluorine) (PVDF) membranes were grafted by gamma-ray irradiation and were sulfonated by sodium sulfite to modify the surface of the membranes. The characteristics of the modified PVDF membranes were evaluated by the data of Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FE-SEM), the contact angle of the membrane surface and the water permeability. From the results of FT-IR, XPS and FE-SEM, it was shown that the modified membranes were successfully grafted by gamma-ray irradiation and were sulfonated. The content of oxygen and sulfur increased with the monomer concentration, while the content of fluorine sharply decreased. The pore size of the modified membranes decreased after gamma-ray irradiation. The contact angle and the water permeability showed that the hydrophilicity of the modified membranes played a role in determining the membrane performance. The feasibility study of the modified PVDF membranes for using non-potable water reuse were carried out using a laboratory-scale microfiltration system. Grey wastewater was used as the influent in the filtration unit, and permeate quality satisfied non-potable water reuse guidelines in the Republic of Korea.

Factors affecting aggression in South Korean middle school students.

PURPOSE: The study was undertaken to assess levels of aggression, and to determine factors affecting aggression among South Korean middle school students. METHODS: A descriptive study was conducted using self-report questionnaires. The participants were 340 girls and boys from two middle schools and 302 questionnaires were used for the final data analysis. Aggression, academic stress, depression, self esteem, decision-making competency, and happiness were measured. Data were analyzed using descriptive statistics including t tests, one-way analysis of variance, Pearson's correlation coefficients and multiple regressions. RESULTS: Aggression had significant correlations with academic stress (r = .21, p < .001), depression (r = .43, p < .001), self esteem (r = -.25, p < .001), decision-making competency (r = -.25, p < .001), and happiness (r = -.21, p < .001). Mean score for aggression was 2.49 out of 5. Significant explanatory variables for aggression were grade (t = 4.39, p < .001), academic stress (t = 2.78, p = .006), and depression (t = 5.03, p < .001). The explanatory power of these factors was 26.9%, and this was statistically significant (F = 16.06, p < .001). CONCLUSION: Findings indicate that depression, academic stress, and grade (second grade) influence aggression. To decrease aggressive behavior, it is necessary to provide systematic and political programs in schools and local communities that can ameliorate negative emotional factors like depression and academic stress. Additionally, development of positive factors such as self esteem, decision-making skills, and happiness in middle school students is important to reduce aggression.

Effects of autogenic training on stress response and heart rate variability in nursing students.

PURPOSE: This study was undertaken to confirm the effects of autogenic training (AT) on stress response and heart rate variability in nursing school students experiencing stress related to clinical training. METHODS: The study was carried out from September 2012 to April 2013 in a quasi-experimental nonequivalent control group using a pretest-posttest design. The participants were 40 nursing students in their third year at either of two nursing colleges. All consented to participate. Nineteen nursing students at one college were assigned to the experimental group and underwent the 8-week AT program, and the other 21 were assigned to the control group and did not undergo any training. Stress response was assessed by questionnaire and HRV was measured three times, that is, before the program, at the end of the program, and 6 months after the end of the AT program. RESULTS: A significant time/group interaction was found for stress response (F = 4.68, p = .012), a subjective indicator. However, no significant interaction was found for the objective indicators of heart rate variability, normalized low frequency (F = 2.59, p = .090), normalized high frequency (F = 2.59, p = .090), or low frequency to high frequency ratio (F = 1.38, p = .257). CONCLUSION: The results suggest that AT provides an acceptable approach to stress reduction in nursing students.

Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics.

Enhancement of struvite purity by re-dissolution of calcium ions in synthetic wastewaters.

Although it is widely known that the presence of Ca ions inhibits the nucleation and growth of struvite, which consists of NH4(+), PO4(3-), and Mg(2+), there is a lack of knowledge on actual Ca contents in struvite co-precipitates at various N and P concentrations and the corresponding effects on the sizes of the precipitates. Therefore, to address this challenge, this study designed synthetic wastewaters including the variety of N and P concentrations, and conducted batch experimental reactions with each wastewater to investigate Ca precipitation and size distributions of the precipitates. The molar ratio of Mg:P:N was confined to 1:1:7, while the initial Ca(2+) concentrations were chosen to be 30-60 mg/L, which are typical Ca concentrations in real wastewaters. The result of the batch experiments confirmed that the presence of Ca caused smaller solids than struvite as indicated in previous studies, and there was competition between Ca-phosphate and Mg-N- PO4 (struvite) reactions, as expected. At the beginning of the experiment (∼1 min), fast Ca-phosphate precipitation was dominant because free Ca and P ions were quickly removed while Mg and N concentrations gradually reduced. However, as the nucleation and crystal growth processes elapsed, dissolved Mg and N concentrations continuously decreased, but dissolved Ca concentrations could rise again at high N and P concentration conditions. The interesting phenomenon is that such increases of Ca concentrations probably results from the thermodynamic energy differences between struvite and Ca-phosphate formations. A high thermodynamic driving force of struvite precipitation could drive the re-dissolution of Ca-ions from the Ca-phosphate compounds with low saturation states. This result is expected to be applied for increasing the struvite purity by the Ca re-dissolution through the thermodynamic spontaneity without additional energy input.

Estimating the fates of organic contaminants in an aquifer using QSAR.

The quantitative structure activity relationship (QSAR) model, BIOWIN, was modified to more accurately estimate the fates of organic contaminants in an aquifer. The predictions from BIOWIN were modified to include oxidation and sorption effects. The predictive model therefore included the effects of sorption, biodegradation, and oxidation. A total of 35 organic compounds were used to validate the predictive model. The majority of the ratios of predicted half-life to measured half-life were within a factor of 2 and no ratio values were greater than a factor of 5. In addition, the accuracy of estimating the persistence of organic compounds in the sub-surface was superior when modified by the relative fraction adsorbed to the solid phase, 1/Rf, to that when modified by the remaining fraction of a given compound adsorbed to a solid, 1 - fs.

Effects of electron beam irradiation and temperature on the treatment of swine wastewater using an ion exchange biological reactor.

Swine wastewater was treated using an ion exchange biological reactor (IEBR). Organic matter and nutrient in swine wastewater were pre-treated by electron beam irradiation. The optimal dose for solubilization of organic matter in swine wastewater ranged from 20 kGy to 75 kGy. The carbohydrates, proteins, and lipids were investigated as proteins and lipids mainly contained the solubilized organic matter. The solubilization of organic matter in swine wastewater was affected by the combination effects of temperature and dose. The maximum chemical oxygen demand (COD) and ammonia removal efficiencies were 74.4% and 76.7% at a dose of 0 kGy under room temperatures (23.0°C). The removal of ammonia was significantly affected by low temperature (15.3°C). On the other hand, the removal of phosphorus was not a function of electron beam irradiation or temperature because struvite is one of the main removal mechanisms under anoxic conditions.

Prediction of the potential fates of future pharmaceutical compounds in indirect potable reuse systems.

The potential fates in indirect potable reuse systems of 2179 pharmaceutical compounds that currently have been used or may be introduced within the next five years were estimated using a modified quantitative structure activity relationship model. Over 90% of the pharmaceutical compounds analyzed were estimated in this study as non-persistent in indirect potable reuse systems where the final removal barrier was sub-surface transport. The removal mechanisms of biodegradation and sorption were considered in assessing their persistence. The percentage of compounds produced by biotechnology was expected to increase from less than 20% to greater than 60% in the near future and this should result in a trend of decreasing persistence for future compounds. The potential rejection in indirect potable reuse systems that use reverse osmosis (RO) as the primary barrier was statistically evaluated. In order to evaluate RO performance, a multiple linear regression analysis was done using SPSS (ver. 17) and the main rejection mechanism for low molecular weight compounds was electrostatic repulsion. Treatment by RO is capable of removing greater than 95% of future compounds and would be expected to perform as efficiently as with currently used compounds.

Estimating the persistence of organic contaminants in indirect potable reuse systems using quantitative structure activity relationship (QSAR).

Predictions from the quantitative structure activity relationship (QSAR) model EPI Suite were modified to estimate the persistence of organic contaminants in indirect potable reuse systems. The modified prediction included the effects of sorption, biodegradation, and oxidation that may occur during sub-surface transport. A retardation factor was used to simulate the mobility of adsorbed compounds during sub-surface transport to a recovery well. A set of compounds with measured persistent properties during sub-surface transport was used to validate the results of the modifications to the predictions of EPI Suite. A comparison of the predicted values and measured values was done and the residual sum of the squares showed the importance of including oxidation and sorption. Sorption was the most important factor to include in predicting the fates of organic chemicals in the sub-surface environment.

Degradation and toxicity assessment of sulfamethoxazole and chlortetracycline using electron beam, ozone and UV.

Recently, the occurrence of antibiotics in sewage treatment plant effluent, as well as drinking water, has raised concern about their potential impacts on the environment and public health. Antibiotics are found in surface and ground waters, which indicate their ineffective removal by conventional wastewater treatment processes. Therefore, advanced oxidation processes (AOPs) have received considerable attention for the removal of antibiotics. This study was conducted to evaluate the degradation and mineralization of antibiotics (sulfamethoxazole and chlortetracycline) using an electron beam, ozone and UV, and the change of toxicity. Also, the electrical energy consumption based on the EE/O parameter (the electrical energy required per order of pollutants removal in 1 m(3) wastewater) was used to quantify the energy cost associated with the different AOPs (electron beam, ozone and UV) for the degradation of antibiotics. The results showed that an electron beam effective for the removals of both sulfamethoxazole and chlortetracycline in aqueous solutions. However, degradation of the target compounds by ozone and UV showed different trends. The oxidation efficiency of each organic compound was very dependent upon the AOP used. Algal toxicity was significantly reduced after each treatment. However, based on the electrical energy, the electron beam was more efficient than ozone and UV. Electron beam treatment could be an effective and safe method for the removal of antibiotic compounds.

[Role transition from clinical nurse to case manager for Medical-aid beneficiaries: taking root in a barren land].

PURPOSE: The purpose of this study was to explain the role transition process to nurse case managers (NCMs) for Medical-aid beneficiaries in Korea. METHODS: Fourteen NCMs were interviewed regarding their experiences of becoming proficient in the new role of case manger. Data were analyzed through the application of grounded theory. RESULTS: 'Taking root in a barren land' was the core category explaining the role transition process of NCMs. They engaged in four stages: launching, trial and error, proficiency, and wait-and-see stages. NCMs showed not only fear but also passion for case management practice. Despite their passion and effort, NCMs went through a period of trial and error. After becoming skilled, NCMs went through a stage of wait-and-see often because of job insecurity related to temporary position or few opportunities for promotion. Factors influencing NCMs' role transition process included their understanding of client characteristics, belief in case management, and support from their colleagues and families. CONCLUSION: NCMs experience many challenges in the process of becoming proficient NCMs. To help with their role transition, there is a need for education programs, preceptorship programs, research on their roles and functions, and regulation for securing NCMs' employment and career stability.

Swine wastewater treatment using a unique sequence of ion exchange membranes and bioelectrochemical system.

An ion exchange biological reactor (IEBR) treated organic matter and nitrogen in swine wastewater at 23 °C. The enhanced IEBR enhanced the ammonium flux by electrochemical attraction. The abiotic ammonium fluxes at the applied voltage of 0, 1, and 3 V were 1.33, 1.79, and 2.73 mg/m(2)/s, respectively. In the meantime, the ammonium fluxes caused by biological nitrification at the applied voltage of 0, 1, and 3 V were 1.54, 2.07, and 3.59 mg/m(2)/s, respectively. Removal of organic matter and nitrogen in swine wastewater was proportional to the applied voltage. The average SCOD removal efficiencies at the applied voltage of 0, 1, and 2V were 59.7%, 60.2%, and 67.0%, respectively. The average total nitrogen removal efficiencies at the applied voltage of 0, 1, and 2V were 39.8%, 49.5%, and 58.7%, respectively.

A kinetic analysis and experimental validation of an integrated system of anaerobic filter and biological aerated filter.

An anaerobic/aerobic filter (AF/BAF) system was developed treating dairy wastewater. The influent was blended with recirculated effluent to allow for pre-denitrification in the AF followed by nitrification in the BAF. The recirculation ratio ranged 100-300%. The average chemical oxygen demand (COD) removal efficiency was 79.8-86.8% in the AF and the average total nitrogen removal efficiency was 50.5-80.8% in the AF/BAF system. Steady-state mass balances on the AF were used to analyze removal kinetics in the AF. The kinetic model values for effluent COD in the AF were overestimated as compared with experimental data. The integrated suspended and attached biomass growth rates in the AF were estimated. The specific growth rate of the integrated biomass at each recirculation ratios was 0.6213, 0.6647, and 1.20831/day, respectively. The increase in specific growth rate corresponded to increases in biomass sloughing as the recirculation ratio increased.

Evaluation of a static granular bed reactor using a chemical oxygen demand balance and mathematical modeling.

In order to evaluate the static granular bed reactor (SGBR), a chemical oxygen demand (COD) balance was used along with a mathematical model. The SGBR was operated with an organic loading rate (OLR) ranging from 0.8 to 5.5 kg/m(3) day at 24°C. The average COD removal efficiency was 87.4%, and the removal efficiencies of COD, carbohydrates, and proteins increased with an OLR, while the lipids removal efficiency was not a function of an OLR. From the results of the COD balance, the yield of biomass increased with an OLR. The SGBR was modeled using the general transport equation considering advection, diffusion, and degradation by microorganisms, and the first-order reaction rate constant was 0.0166/day. The simulation results were in excellent agreement with experimental data. In addition, the SGBR model provided mechanistic insight into why the COD removal efficiency in the SGBR is proportional to an OLR.

A kinetic evaluation of anaerobic treatment of swine wastewater at two temperatures in a temperate climate zone.

A static granular bed reactor (SGBR) was used to treat swine wastewater at 24 and 16°C. At 24°C, the organic loading rate (OLR) was 0.7-5.4 kg COD/m(3)day and the average chemical oxygen demand (COD) removal efficiency was 88.5%, respectively. Meanwhile, at 16°C, the OLR was 1.6-4.0 kg COD/m(3)day and the average COD removal efficiency was 68.0%, respectively. The SGBR acted as a bioreactor as well as a biofilter. After backwashing, the recovery of COD removal was not a function of an OLR but recovery time, while that of TSS removal was not a function of either recovery time or the OLR. The maximum substrate utilization rate (k(max)) ratio was 1.89 between 24 and 16°C, and the half velocity constant (K(s)) ratio was 1.22, and the maximum specific growth rate (µ(max)) ratio was 4.71. In addition, the temperature-activity coefficient in this study was determined to be 1.09.