Synergistic effects of ε-poly-l-lysine and lysozyme against Pseudomonas aeruginosa and Listeria monocytogenes biofilms on beef and food contact surfaces.

This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms of two bacteria were formed on silicone rubber (SR), stainless steel (SS), and beef surfaces and then treated with lysozyme (0.05-5 mg/mL) and ε-PL at minimum inhibitory concentrations (MICs) of 1 to 4 separately or in combination. On the SR surface, P. aeruginosa biofilm was reduced by 1.4 and 1.9 log CFU/cm2 within 2 h when treated with lysozyme (5 mg/mL) and ε-PL (4 MIC), respectively, but this reduction increased significantly to 4.1 log CFU/cm2 (P < 0.05) with the combined treatment. On beef surface, P. aeruginosa and L. monocytogenes biofilm was reduced by 4.2-5.0, and 3.3-4.2 log CFU/g when lysozyme was combined with 1, 2, and 4 MIC of ε-PL at 25 °C, respectively. Compared to 5 mg/mL lysozyme alone, the combined treatment with 1, 2, and 4 MIC of ε-PL on beef surface achieved additional reduction against P. aeruginosa biofilm of 0.5, 0.8, and 0.7 log CFU/g, respectively, at 25 °C. In addition, 0.25 mg/mL lysozyme and 0.5 MIC of ε-PL significantly (P < 0.05) suppressed the quorum-sensing (agrA) and virulence-associated (hlyA and prfA) genes of L. monocytogenes.

Assessing the potential of ChatGPT for psychodynamic formulations in psychiatry: An exploratory study.

Although there were several attempts to apply ChatGPT (Generative Pre-Trained Transformer) to medicine, little is known about therapeutic applications in psychiatry. In this exploratory study, we aimed to evaluate the characteristics and appropriateness of the psychodynamic formulations created by ChatGPT. Along with a case selected from the psychoanalytic literature, input prompts were designed to include different levels of background knowledge. These included naïve prompts, keywords created by ChatGPT, keywords created by psychiatrists, and psychodynamic concepts from the literature. The psychodynamic formulations generated from the different prompts were evaluated by five psychiatrists from different institutions. We next conducted further tests in which instructions on the use of different psychodynamic models were added to the input prompts. The models used were ego psychology, self-psychology, and object relations. The results from naïve prompts and psychodynamic concepts were rated as appropriate by most raters. The psychodynamic concept prompt output was rated the highest. Interrater agreement was statistically significant. The results from the tests using instructions in different psychoanalytic theories were also rated as appropriate by most raters. They included key elements of the psychodynamic formulation and suggested interpretations similar to the literature. These findings suggest potential of ChatGPT for use in psychiatry.

Influence of body shape on health-related quality of life in Korean adults: The mediating effect of self-rated health.

A Body Shape Index (ABSI) predicts mortality independent of body mass index and had a negative relationship with self-rated health (SRH), which had a positive effect on the EuroQol (EQ)-5D index. This study aimed to investigate the relationship between ABSI and the EQ-5D index and to verify the mediating effect of SRH in Korean adults. This study included 13,381 participants aged ≥20 years from the 7th (2016-2018) Korean National Health and Nutrition Examination Survey (KNHANES). The participants were classified into tertile groups based on the ABSI (T1, T2, and T3 groups). Demographic characteristics, health-related factors, ABSI, SRH, and EQ-5D scores were evaluated. Women (p<0.001), rural areas (p<0.001), married persons (p<0.001), low education level (p<0.001), low income (p<0.001), and older age (p<0.001) were higher in the T3 group. The monthly drinking (p<0.001), current smoking (p<0.001), and mental stress rates (p<0.001) were the highest in the T1 group. The overall average SRH scores and EQ-5D index were 3.08 points and 0.94 points, respectively. ABSI and SRH (r = -0.161, p<0.001) and ABSI and EQ-5D (r = -0.229, p<0.001) showed a negative correlation. However, SRH and EQ-5D scores (r = 0.433, p<0.001) were positively correlated. The overall effect of the independent variable ABSI on the dependent variable EQ-5D was -0.959. SRH partially mediated the effect of ABSI on EQ-5D (indirect effect coefficient = -0.200). These results can be used as basic data to develop strategies and programs to improve health-related quality of life by adjusting ABSI and SRH.

Overview of the National Cancer Screening Program for Colorectal Cancer in Korea over 14 Years (2004-2017).

PURPOSE: This study aimed to evaluate the participation and follow-up test compliance rates and key performance indicators of the National Cancer Screening Program (NCSP) for colorectal cancer (CRC) from 2004 to 2017. Materials and Methods: The overall outcomes of the NCSP for CRC were analyzed using the NCSP data collected from 2004 to 2017 and the Korean Central Cancer Registry for CRC from 2005 to 2017. We cross-sectionally analyzed the participation and follow-up test compliance rates and performance indicators for each year. The trend of participation rates as an annual percentage change was assessed, and other statistical analyses were performed. RESULTS: The screening participation rates increased from 7.3% in 2004 to 30.5% in 2017. Additionally, the screening rates were higher among individuals aged 60-69 years and National Health Insurance Service beneficiaries of low-income status. However, the adherence to the follow-up test decreased from 63% in 2004 to 32% in 2017. The follow-up tests using the double-contrast barium enema method decreased from 42.2% in 2004 to 0.3% in 2017. However, follow-up tests by colonoscopy increased from 21.0% in 2004 to 31.8% in 2017. Furthermore, the positivity, false-positive, and interval CRC rates decreased, whereas the specificity increased from 2004 to 2016, indicating improved performance of CRC. CONCLUSION: The participation rates and performance of the NCSP for CRC have steadily improved, whereas adherence to follow-up tests has decreased. Additionally, there is a rapid growth in colonoscopy volume as a follow-up test. Continued efforts are required to improve the follow-up rates.

Regional disparities related to cardiovascular diseases and diet quality in Korean adults: based on the 2013-2016 Korea National Health and Nutrition Examination Survey Data.

BACKGROUND/OBJECTIVES: Cardiovascular diseases (CVDs) are the leading cause of death in Koreans, and eating habits, including diet quality, are among the etiologies of these diseases. Recently, various studies on regional health disparities have been conducted. However, there are limited studies on their relationship with nutritional factors. This study aimed to identify the magnitude of regional disparities in diet quality and prevalence of CVD in Korean adults. SUBJECTS/METHODS: This study included 17,646 participants aged ≥ 20 years from the 7th (2013-2016) Korean National Health and Nutrition Examination Survey. Participants were classified into four groups based on their residential areas: City 1, City 2, City 3, and non-city. Demographic characteristics, health-related factors, body mass index (BMI), metabolic syndrome index, diet quality, and CVD prevalence were evaluated. RESULTS: In terms of demographic characteristics, age (P < 0.001), marital status (P < 0.001), educational level (P < 0.001), and income (P < 0.001) were lower in the non-city category. Health-related factors such as monthly drinking rate (P < 0.01) and mental stress (P < 0.05) were the highest in City 1 and lowest in the non-city group. Conversely, the current smoking rate (P < 0.05), BMI (P < 0.05), and prevalence of metabolic syndrome (P < 0.001) were the highest in the non-city group (P < 0.05). The non-city group also had the highest prevalence of CVDs (35.6%). This group had the lowest diet quality index (68.36 ± 0.22, P < 0.01), caused by low intake of fruit and calcium, a lack of sodium moderation, and an overall imbalance in the macronutrient and fatty acid ratio. When the diet quality index was increased by 1, the odds ratio for the prevalence of CVDs was reduced by 0.991 (P < 0.001), but this was not the case in all regions. CONCLUSIONS: This study provides useful information and data in identifying and resolving the regional health disparities related to CVD prevalence and implementation of public health nutrition systems.

Lower-Income Predicts Increased Smartphone Use and Problematic Behaviors Among Schoolchildren During COVID-19 Related School Modification: A Longitudinal Study.

BACKGROUND: As the coronavirus disease 2019 (COVID-19) has continued for a couple of years, the long-term effects of the pandemic and the subsequent school curriculum modification on the mental health of children and parents need to be investigated. To clarify the changes that can occur during one school year and to predict the risk factors for vulnerable groups, this study identified parameters relative to children's screen time, their problematic behavior, and parental depression. METHODS: A total of 186 participants were analyzed who were parents of elementary schoolchildren in South Korea. These parents were required to complete a web-based questionnaire twice. The questionnaires were conducted in June 2020 and September 2021. Participants' general demographics including family income, children's screen time, sleep patterns, problematic behavior, and parental depression were assessed via the parental questionnaire that included various measurement tools. RESULTS: Children's body mass index (BMI) increased significantly in 2021 (18.94 ± 3.75 vs. 18.14 ± 3.30, P < 0.001). Smartphone frequency of use per week (5.35 vs. 4.54, P < 0.001) and screen time per day (3.52 vs. 3.16, P < 0.001) significantly increased during the period of the COVID-19 pandemic. The television screen time (2.88 vs. 3.26, P < 0.001), frequency of viewing (3.77 vs. 4.77, P < 0.001), and children's problematic behaviors significantly decreased (9.15 vs. 11.85, P < 0.001). A lower income household was a key predictor of increased smartphone frequency (B = 1.840, 95% confidence interval [CI], 0.923-2.757, P < 0.001) and smartphone screen time (B = 1.992, 95% CI, 1.458-2.525, P < 0.001). The results showed that the lower income household (B = 5.624, 95% CI, 2.927-8.320, P < 0.001) and a child's psychiatric treatment history (B = 7.579, 95% CI, 5.666-9.492, P < 0.001) was the most significant predictor of problematic behaviors of children and parental depression (B = 3.476, 95% CI, 1.628-5.325, P < 0.001; B = 3.138, 95% CI, 1.827-4.450, P < 0.001). CONCLUSION: This study suggested that children's smartphone screen time and BMI increased during COVID-19 because of the school curriculum modification following school closures in South Korea. The increased children's problematic behaviors and parental depression were predicted by lower-income households and the previous psychiatric history of children. These results indicate that multiple social support systems to the vulnerable group are needed during the ongoing pandemic and that a modified school setting is required.

Elevation of the D-dimer cut-off level might be applicable to rule out pulmonary embolism for active cancer patients in the emergency department.

Recent guidelines for diagnosing acute pulmonary embolism (PE) are based on clinical decision rules and D-dimer. D-dimer measurement is recommended only for patients who are 'PE-unlikely'. We aimed to assess the current guidelines for cancer patients and to determine an optimal D-dimer cut-off level. This retrospective observational study was conducted in the emergency department of Asan Medical Center (Seoul, Korea) between 02/2017 and 09/2017 for the development cohort and between 06/2018 and 02/2019 for the validation cohort. Among adult active cancer patients with suspected PE, we included those who were 'PE-unlikely' according to Wells' criteria and who underwent D-dimer testing and computed tomographic pulmonary angiography (CTPA). A total of 498 patients (227 in the development cohort and 271 in the validation cohort) were included, and PE was diagnosed in 8.8% and 18.5% of patients, respectively. The optimal D-dimer cut-off level was 2.0 µg/mL. This elevated cut-off level showed a much higher specificity of 21.3% (95% confidence interval [CI] 16.2-27.3%) and 21.7% (95% CI 16.8-7.6%) in the development and validation sets, respectively, compared with the specificity of 4.4% (95% CI 2.3-8.1%) and 4.1% (95% CI 2.2-7.6%) using the age-adjusted cut-off. The new D-dimer cut-off value identified unnecessary CTPA for 21.3% of patients (absolute difference, 16.9%, 35 of 207) in the development cohort and 21.7% (absolute difference, 17.6%, 39 of 221) of patients in the validation cohort compared to using the standard age-adjusted cut-off. The elevated D-dimer cut-off value combined with Wells' criteria might reduce unnecessary CTPA in active cancer patients with a 'PE-unlikely' classification. Further clinical trials are warranted to improve the PE diagnostic strategy in cancer patients.

Trends in Participation Rates of the National Cancer Screening Program among Cancer Survivors in Korea.

The study aimed to describe the participation rates of the National Cancer Screening Program (NCSP) among cancer survivors in Korea. The NCSP protocol recommends that all Korean men and women should be screened for cancer. Cancer survivors were defined as those registered for any cancer in the Korea Central Cancer Registry by December 31 of the year prior to being included in the target population of the NCSP. In this study, the participation rates for the NCSP were calculated as the percentage of people who participated in four kinds of cancer screening programs, independently. The average annual percentage change was assessed. The participation rates of the general population and cancer survivors were higher than 40% in stomach, breast, and cervical cancer screening. These rates were higher than that of colorectal cancer screening in 2014. In addition, the participation rates in the NCSP in 2002-2014 increased for all cancer types. The NCSP participation rates of the cancer survivors indicate the high demand for cancer screening. Further research may investigate the effect of the NCSP on second cancer occurrence or mortality in cancer survivors and the significance of cancer screening guidelines for cancer survivors.

Distinct Roles of Parvalbumin- and Somatostatin-Expressing Interneurons in Working Memory.

Inhibitory interneurons are thought to play crucial roles in diverse brain functions. However, roles of different inhibitory interneuron subtypes in working memory remain unclear. We found distinct activity patterns and stimulation effects of two major interneuron subtypes, parvalbumin (PV)- and somatostatin (SOM)-expressing interneurons, in the medial prefrontal cortex of mice performing a spatial working memory task. PV interneurons showed weak target-dependent delay-period activity and were strongly inhibited by reward. By contrast, SOM interneurons showed strong target-dependent delay-period activity, and only a subtype of them was inhibited by reward. Furthermore, optogenetic stimulation of PV and SOM interneurons preferentially suppressed discharges of putative pyramidal cells and interneurons, respectively. These results indicate different contributions of PV and SOM interneurons to prefrontal cortical circuit dynamics underlying working memory.

Neuronal activity in dorsomedial and dorsolateral striatum under the requirement for temporal credit assignment.

To investigate neural processes underlying temporal credit assignment in the striatum, we recorded neuronal activity in the dorsomedial and dorsolateral striatum (DMS and DLS, respectively) of rats performing a dynamic foraging task in which a choice has to be remembered until its outcome is revealed for correct credit assignment. Choice signals appeared sequentially, initially in the DMS and then in the DLS, and they were combined with action value and reward signals in the DLS when choice outcome was revealed. Unlike in conventional dynamic foraging tasks, neural signals for chosen value were elevated in neither brain structure. These results suggest that dynamics of striatal neural signals related to evaluating choice outcome might differ drastically depending on the requirement for temporal credit assignment. In a behavioral context requiring temporal credit assignment, the DLS, but not the DMS, might be in charge of updating the value of chosen action by integrating choice, action value, and reward signals together.

Wafer-scale surface roughening for enhanced light extraction of high power AlGaInP-based light-emitting diodes.

A new approach to surface roughening was established and optimized in this paper for enhancing the light extraction of high power AlGaInP-based LEDs, by combining ultraviolet (UV) assisted imprinting with dry etching techniques. In this approach, hexagonal arrays of cone-shaped etch pits are fabricated on the surface of LEDs, forming gradient effective-refractive-index that can mitigate the emission loss due to total internal reflection and therefore increase the light extraction efficiency. For comparison, wafer-scale FLAT-LEDs without any surface roughening, WET-LEDs with surface roughened by wet etching, and DRY-LEDs with surface roughened by varying the dry etching time of the AlGaInP layer, were fabricated and characterized. The average output power for wafer-scale FLAT-LEDs, WET-LEDs, and DRY3-LEDs (optimal) at 350 mA was found to be 102, 140, and 172 mW, respectively, and there was no noticeable electrical degradation with the WET-LEDs and DRY-LEDs. The light output was increased by 37.3% with wet etching, and 68.6% with dry etching surface roughening, respectively, without compromising the electrical performance of LEDs. A total number of 1600 LED chips were tested for each type of LEDs. The yield of chips with an optical output power of 120 mW and above was 0.3% (4 chips), 42.8% (684 chips), and 90.1% (1441 chips) for FLAT-LEDs, WET-LEDs, and DRY3-LEDs, respectively. The dry etching surface roughening approach developed here is potentially useful for the industrial mass production of wafer-scale high power LEDs.

Thermal stability of superhydrophobic, nanostructured surfaces.

The thermal stability of superhydrophobic, nanostructured surfaces after thermal annealing was explored. Flat surfaces coated with hydrophobic diamond-like carbon (DLC) via plasma polymerization of hexamethyldisiloxane (HMDSO) showed a gradual decrease in the water contact angle from 90(o) to 60(o) while nanostructured surfaces maintained superhydrophobicity with more than 150° for annealing temperatures between 25 and 300°C. It was also found that surfaces with nanostructures having an aspect ratio of more than 5.2 may maintain superhydrophobicity for annealing temperatures as high as 350°C; above this temperature, however, the hydrophobicity on surfaces with lower aspect ratio nanostructures gradually degraded. It was observed that regardless of the aspect ratios of the nanostructure, all superhydrophobic surfaces became superhydrophilic after annealing at temperatures higher than 500°C.

Bioinspired steel surfaces with extreme wettability contrast.

The exterior structures of natural organisms have continuously evolved by controlling wettability, such as the Namib Desert beetle, whose back has hydrophilic/hydrophobic contrast for water harvesting by mist condensation in dry desert environments, and some plant leaves that have hierarchical micro/nanostructures to collect or repel liquid water. In this work, we have provided a method for wettability contrast on alloy steels by both nano-flake or needle patterns and tuning of the surface energy. Steels were provided with hierarchical micro/nanostructures of Fe oxides by fluorination and by a subsequent catalytic reaction of fluorine ions on the steel surfaces in water. A hydrophobic material was deposited on the structured surfaces, rendering superhydrophobicity. Plasma oxidization induces the formation of superhydrophilic surfaces on selective regions surrounded by superhydrophobic surfaces. We show that wettability contrast surfaces align liquid water within patterned hydrophilic regions during the condensation process. Furthermore, this method could have a greater potential to align other liquids or living cells.

Fabrication of superhydrophobic surfaces with high and low adhesion inspired from rose petal.

Certain rose petals are known to be superhydrophobic with high adhesion. There also exist rose petals which are superhydrophobic with low adhesion similar to lotus leaf. The purpose of this study is to characterize systematically the superhydrophobic rose petal with high and low adhesion surfaces and understand the mechanism for adhesion characteristics. Based on these, artificial superhydrophobic surfaces with high and low adhesion are fabricated using a two-step molding process and wax evaporation method. It is shown that the pitch values of microstructures and density of nanostructures play an important role in real rose petals and artificial surfaces to control their adhesion properties.

An angled nano-tunnel fabricated on poly(methyl methacrylate) by a focused ion beam.

Angled nano-scale tunnels with high aspect ratio were fabricated on poly(methyl methacrylate) (PMMA) using a focused ion beam (FIB). The fabrication parameters such as ion fluence, incidence angle, and acceleration voltage of the Ga(+) ion beam were first studied on the PMMA surface to explore the formation of the nano-scale configurations such as nano-holes and cones with diameter in the range of 50-150 nm at an ion beam acceleration voltage of 5-20 kV. It was also found that the PMMA surface exposed to FIB was changed into an amorphous graphitic structure. Angled nano-scale tunnels were fabricated with high aspect ratio of 700-1500 nm in depth and 60 nm in mean diameter at an ion beam acceleration voltage of 5 kV and under a specific ion beam current. The angle of the nano-tunnels was found to follow the incident angle of the ion beam tilted from 0 degrees to 85 degrees , which has the potential for creating a mold for anisotropic adhesives by mimicking the hairs on a gecko's feet.

Nanoscale ripples on polymers created by a focused ion beam.

We show that focused ion beam irradiation results in the creation of peculiar one- and two-dimensional nanoscale features on the surface of polyimide-a common polymer in electronics, large scale structures, and the automobile industry, as well as in biomedical applications. The role of ion beam incident angle, acceleration voltage, and fluence on the morphology of the structural features is systematically investigated, and insights into the mechanisms of formation of these nanoscale features are provided. Moreover, by using the maskless patterning method of the focused ion beam system, we have developed a robust technique for controlled modification of the polymeric surface. The technique, which is analogous to using a gray glass with varying darkness to control the radiation from the sun, but at a much smaller scale, enables the ion intensity and angle to be controlled at each surface point of the polymer, giving rise to structural surface features with desired shape and morphology.