Self-Powering Gas Sensing System Enabled by Double-Layer Triboelectric Nanogenerators Based on Poly(2-vinylpyridine)@BaTiO3 Core-Shell Hybrids with Superior Dispersibility and Uniformity.

Current core-shell hybrids used in diverse energy-related applications possess limited dispersibility and film uniformity that govern their overall performances. Herein, we showcase superdispersible core-shell hybrids (P2VP@BaTiO3) composed of a poly(2-vinylpyridine) (P2VP) (5-20 wt %) and a barium titanate oxide (BaTiO3), maximizing dielectric constants by forming the high-quality uniform films. The P2VP@BaTiO3-based triboelectric nanogenerators (TENGs), especially the 10 wt % P2VP (P2VP10@BaTiO3)-based one, deliver significantly enhanced output performances compared to physically mixed P2VP/BaTiO3 counterparts. The P2VP10@BaTiO3-based double-layer TENG exhibits not only an excellent transferred charge density of 281.7 µC m-2 with a power density of 27.2 W m-2 but also extraordinary device stability (∼100% sustainability of the maximum output voltage for 54,000 cycles and ∼68.7% voltage retention even at 99% humidity). Notably, introducing the MoS2/SiO2/Ni-mesh layer into this double-layer TENG enables ultrahigh charge density of up to 1228 µC m-2, which is the top value reported for the TENGs so far. Furthermore, we also demonstrate a near-field communication-based sensing system for monitoring CO2 gas using our developed self-powered generator with enhanced output performance and robustness.

High-Precision Tailored Polymer Molecular Weights for Specific Photovoltaic Applications through Ultrasound-Induced Simultaneous Physical and Chemical Events.

It is highly challenging to reproducibly prepare semiconducting polymers with targeted molecular weight tailored for next-generation photovoltaic applications. Once such an easily accessible methodology is established, which can not only contribute to overcome the current limitation of the statistically determined nature of semiconducting polymers, but also facilitate rapid incorporation into the broad synthetic chemists' toolbox. Here, we describe a simple yet robust ultrasonication-assisted Stille polymerization for accessing semiconducting polymers with high-precision tailored molecular weights (from low to ultrahigh molecular weight ranges) while mitigating their interbatch variations. We propose that ultrasound-induced simultaneous physical and chemical events enable precise control of the semiconducting polymers' molecular weights with high reproducibility to satisfy all the optical/electrical and morphological demands of diverse types of high-performance semiconducting polymer-based devices; as demonstrated in in-depth experimental screenings in applications of both organic and perovskite photovoltaics. We believe that this methodology provides a fast development of new and existing semiconducting polymers with the highest-level performances possible on various photovoltaic devices.

Multifunctional Acrylic Polymers with Enhanced Adhesive Property Serving as Excellent Edge Encapsulant for Stable Optoelectronic Devices.

Pendant groups in acrylic adhesive polymers (Ads) have a profound influence on adhesive and cohesive properties and additionally on encapsulant application. However, a systematic investigation to assess the impact of the pendant groups' length and bulkiness is rare, and there is not even a single report on applying Ads as interfacial adhesion promotors and encapsulation materials simultaneously. Herein, we have developed a series of multifunctional methacrylic polymers, namely, R-co-Ads, with varying pendant length and bulkiness (R = methyl (C1), ethyl (C2), propyl (C3), butyl (C4), pentyl (C5), hexyl (C6), isobutyl (iC4), and 2-ethylhexyl (2EH)). The adhesion-related experimental results reveal that R-co-Ads have high transparency, strong adhesion strength to the various contact surfaces, and a fast cure speed. In particular, C1-co-Ad shows a superior adhesion performance with an improved cross-cut index of 4B and a shear bonding strength of 1.56 MPa. We also have adopted C1-co-Ad for encapsulation of various emerging optoelectronic applications (e.g., perovskite solar cell-, charge transport-, and conductivity-related characteristics), demonstrating its excellent edge encapsulant served to improve the device stability against ambient air conditions. Our study establishes the structure-adhesion-surface relationships, advancing the better design of adhesives and encapsulants for various research fields.

Octafluoronaphthalene as a thermal-annealing-free volatile solid additive enables high-performance organic solar cells.

A thermal annealing-free solid additive octafluoronaphthalene was developed for high-performance organic solar cells. In an additive-modified device, an impressive power conversion efficiency of 18.59% from 17.27% was achieved with simultaneously enhanced current density from 26.86 to 27.53 mA cm-2 and fill factor from 74.34% to 78.85%.

Conformational Locking Control of 2D Outer Side Chains via Fluorine Atom Positioning for Improving the Thermal Stability of Organic Solar Cells.

Alongside high power conversion efficiencies (PCEs), device stability, especially thermal issues, is another key factor for the successful commercialization of nonfullerene acceptor (NFA)-based organic solar cells (OSCs). Considering the significant effects of the side-chain engineering of NFAs on molecular packing and/or locking strongly associated with the thermal stability of OSCs, herein, we present two new isomeric NFAs with 4-fluoro- and 2-fluoro-substituted hexylphenyl two-dimensional (2D) outer side chains (4FY and 2FY, respectively). In contrast with the 2FY having a horizontal stretching conformation, 4FY exhibits a diagonal stretching conformation of the 2D outer side chains and a higher dipole moment, resulting in a huge difference in their crystalline/aggregation characteristics, i.e., 4FY possesses a higher crystallinity with a denser molecular packing than the 2FY neat film, as evidenced by thermal and morphological characterizations. Encouragingly, relative to the one based on 2FY, the OSC based on 4FY delivers a PCE as high as 16.4%, together with excellent thermal stability (88.4% PCE retention under 85 °C for 360 h), which is attributed to a more optimal and robust blend morphology induced by its better compatibility into the used donor component and stronger crystallinity. This work demonstrates that in addition to the improved photovoltaic property, the appropriate F-positioning on the 2D outer side chains can play a key role in controlling their conformations, which can promote the increase of the thermal stability of OSCs.

γ-Ester-Functionalized 1,1-Dicyanomethylene-3-indanone End-Capped Nonfullerene Acceptors for High-Performance, Annealing-Free Organic Solar Cells.

Modifying the end-capping groups in nonfullerene acceptors (NFAs) is an effective strategy for modulating their properties and that of the entire NFAs. This study reports the synthesis of a novel γ-ester-functionalized IC end-capping group (IC-γe) and its incorporation into the benzothiadiazole-fused central core, yielding isomer-free IC-γe end-capped NFAs, such as Y-IC-γe, Y-FIC-γe, and Y-ClIC-γe. The resultant NFAs exhibited similar absorption profiles but upshifted the lowest unoccupied molecular orbital energy level compared with those of the ester-free analogues, such as Y6 and Y7. Without thermal annealing, an excellent power conversion efficiency (PCE) of 16.4% is realized in the annealing-free OSC based on Y-FIC-γe with the PM6 donor polymer, which outperforms the OSCs based on Y-IC-γe and Y-ClIC-γe. In addition, the OSCs based on asymmetric Y-FIC-γe and Y-ClIC-γe have higher thermal stability with more than 83% PCE retention at an elevated temperature after 456 h than the symmetric Y-IC-γe case. In this study, we not only establish the structure-property relationship regarding the ester functionality and symmetricity tuning on the NFAs but also diagnose the reasons for the best-performing Y-FIC-γe-based OSCs, providing useful information for a novel high-performing NFA design strategy.

Gate-Stack Engineering to Improve the Performance of 28 nm Low-Power High-K/Metal-Gate Device.

In this study, a gate-stack engineering technique is proposed as a means of improving the performance of a 28 nm low-power (LP) high-k/metal-gate (HK/MG) device. In detail, it was experimentally verified that HfSiO thin films can replace HfSiON congeners, where the latter are known to have a good thermal budget and/or electrical characteristics, to boost the device performance under a limited thermal budget. TiN engineering for the gate-stack in the 28 nm LP HK/MG device was used to suppress the gate leakage current. Using the proposed fabrication method, the on/off current ratio (Ion/Ioff) was improved for a given target Ion, and the gate leakage current was appropriately suppressed. Comparing the process-of-record device against the 28 nm LP HK/MG device, the thickness of the electrical oxide layer in the new device was reduced by 3.1% in the case of n-type field effect transistors and by 10% for p-type field effect transistors. In addition, the reliability (e.g., bias temperature instability, hot carrier injury, and time-dependent dielectric breakdown) of the new device was evaluated, and it was observed that there was no conspicuous risk. Therefore, the HfSiO film can afford reliable performance enhancement when employed in the 28 nm LP HK/MG device with a limited thermal budget.

Modeling Healthcare Costs Attributable to Secondhand Smoke Exposure at Home among South Korean Children.

Children exposed to secondhand smoke (SHS) are at increased risk for disease. We sought to estimate the medical costs among Korean children who were exposed to SHS at home. A Markov model was developed, including five diseases (asthma, acute otitis media, acute bronchitis, pneumonia and sudden infant death syndrome) that were significantly associated with SHS in children based on a systematic review. The time horizon of the analysis was 20 years (from birth to adulthood), and the cycle length was 1 week. The direct healthcare costs were discounted annually at 5%. Univariate and probabilistic sensitivity analyses were conducted. The Markov model estimated the healthcare costs for 20 years as 659.61 USD per exposed child, an increase of approximately 30% compared to the cost per unexposed child (507.32 USD). Sensitivity analysis suggested that the younger the age of the exposure, the greater the incremental healthcare costs incurred, implying that infants and young children were especially vulnerable to the SHS exposure. Findings of this study could provide key baseline data for future economic evaluations on SHS control policies in South Korea.

Marketing and Pricing Strategies of Blockbuster Drugs in the South Korean Market: A 15-Year Retrospective Cohort Study for Choline Alfoscerate.

INTRODUCTION: Understanding marketing strategies and price competition among manufacturers is essential to manage health care expenditures, particularly those related to blockbuster drugs. OBJECTIVES: To assess marketing and pricing strategies of blockbuster drugs in South Korea. METHODS: Baseline information on manufacturers who were granted marketing approval for choline alfoscerate in various forms was retrieved. Accumulation of manufacturers in the market was also identified, and manufacturers were categorized into first movers and latecomers based on their marketing time. Then, an event history analysis and a regression analysis were applied to estimate the duration of marketing and their price competition. RESULTS: Currently, 109, 83, and 26 manufacturers produce choline alfoscerate in capsule, tablet, or syrup form, respectively, indicating that many manufacturers have marketed generics and the majority of the generics are categorized as latecomers. The size of the manufacturer was a significant factor in marketing new medicines, while the variable was not related to the marketing of modified drugs. Furthermore, price competition in the market was rare and only a few major firms initiated price competition. CONCLUSION: The Korean market appears to be an example of perfect competition when we focus on the number of manufacturers. However, the market is near-monopolistic when examining the price of generic drugs. While product competition between different forms of drugs is effective in lowering price, product competition within the same form of a drug does not exist in the market.

Effects of an individualised nutritional education and support programme on dietary habits, nutritional knowledge and nutritional status of older adults living alone.

AIMS AND OBJECTIVES: The effects of an individualised nutritional education and support programme on dietary habits, nutritional knowledge and nutritional status of 71 older adults living alone were examined. BACKGROUND: Although a regular dietary meal plan is recommended for improving nutritional status of older adults living alone, little research is done in this field in Korea. DESIGN: A pre- and post-test controlled quasi-experimental design was used at public health centres. METHODS: The intervention group participated in an intensive nutritional education and support programme once a week for 8 weeks with dietary menus provided by home visiting nurses/dieticians; control group received usual care. Dietary habits and nutritional knowledge were assessed using structured questionnaires; nutritional intake status was analysed using Computer Aided Nutritional Analysis Program 5.0. RESULTS: The mean age of participants was 77.6 years, and 81.7% of the participants were women. At 8 weeks, there were significant interactions of group by time for dietary habits, nutritional knowledge and selected nutritional status of protein, iron and vitamins of B2 and C. Changes over time in the mean score of dietary habits and nutritional knowledge were significantly improved in the intervention group compared to the control group. The percentages of normal nutrition intake of protein, iron and vitamins A and C in the intervention group were significantly higher than the control group at 8 weeks. CONCLUSIONS: Nutritional education and support programme positively impacted dietary habits, nutritional knowledge and selected nutritional status in older adults living alone, and we highlight the need for community-based nutritional education and counselling programmes. RELEVANCE TO CLINICAL PRACTICE: Older adults living alone in a community have relatively poor nutritional status and thus require tailored nutritional intervention according to objective nutritional analysis. It is necessary to link visiting nurses with dieticians in the community to manage effective nutritional programme continuously.

Factors affecting aging cognitive function among community-dwelling older adults.

AIM: The study purpose was to determine factors affecting aging cognitive function of 3,645 community-dwelling older adults in Korea. METHODS: The Hasegawa Dementia Scale assessed aging cognitive function, blood analyses and anthropometrics assessed cardio-metabolic risk factors, and the Geriatric Depression Scale Short Form Korean Version assessed depressive symptoms. RESULTS: Participants with poor aging cognitive function were more likely to be in the late age group (≥75 y) and currently smoking and have a medical history of stroke, high body mass index, and high level of depressive symptoms; they were also less likely to engage in regular meals and physical activities. CONCLUSION: Regular meals and physical activities may be primary factors for clinical assessment to identify older adults at risk for aging cognitive function. With aging, depressive symptoms and other unhealthy lifestyle behaviours should be managed to prevent cognitive function disorders.

Evaluation of the Measurement Properties of Self-reported Medication Adherence Instruments Among People at Risk for Metabolic Syndrome: A Systematic Review.

PURPOSE: The purpose of this study was to present a systematic review of available published studies that evaluated the measurement properties of self-reported instruments assessing global medication adherence in adults at risk for metabolic syndrome. METHODS: The authors searched PubMed, EMBASE, PsycINFO, and CINAHL in January 2015 for appropriate studies. The methodological quality (based on reliability, validity, responsiveness, and interpretability) of selected studies was assessed with the COSMIN checklist (Consensus-Based Standards for the Selection of Health Measurement Instruments). RESULTS: Of the 44 studies reviewed, 32 used classical test theory, and 14 used self-reported medication adherence instruments. More than half the studies included patients with hypertension, followed by diabetes, dyslipidemia, and increased body mass index. Among the measurement properties, internal consistency, hypothesis testing, and structural validity were frequently assessed items, whereas only 1 study evaluated responsiveness, and none evaluated measurement error. The MMAS-8 (Morisky Medication Adherence Scale-8 items) and the Hill-Bone scale were the most frequently used instruments. They were found to be well validated, with strong evidence for internal consistency and strong positive evidence for reliability, structural validity, hypothesis testing, and criterion validity. CONCLUSIONS: The MMAS-8 and Hill-Bone scale seem to be well-validated instruments for assessing medication adherence in adults at risk for metabolic syndrome. These findings may assist clinicians with selecting the appropriate instruments for assessing medication adherence in this population. However, further studies might be needed to define concepts to better understand the dimensions of each medication adherence instrument.

Effects of team-based learning on perceived teamwork and academic performance in a health assessment subject.

The purpose of this study was to examine the effectiveness of team-based learning (a well-recognized learning and teaching strategy), applied in a health assessment subject, on nursing students' perceived teamwork (team-efficacy and team skills) and academic performance (individual and team readiness assurance tests, and examination scores). A prospective, one-group, pre- and post-test design enrolled a convenience sample of 74 second-year nursing students at a university in Suwon, Korea. Team-based learning was applied in a 2-credit health assessment subject over a 16-week semester. All students received written material one week before each class for readiness preparation. After administering individual- and team-readiness assurance tests consecutively, the subject instructor gave immediate feedback and delivered a mini-lecture to the students. Finally, students carried out skill based application exercises. The findings showed significant improvements in the mean scores of students' perceived teamwork after the introduction of team-based learning. In addition, team-efficacy was associated with team-adaptability skills and team-interpersonal skills. Regarding academic performance, team readiness assurance tests were significantly higher than individual readiness assurance tests over time. Individual readiness assurance tests were significantly related with examination scores, while team readiness assurance tests were correlated with team-efficacy and team-interpersonal skills. The application of team-based learning in a health assessment subject can enhance students' perceived teamwork and academic performance. This finding suggests that team-based learning may be an effective learning and teaching strategy for improving team-work of nursing students, who need to collaborate and effectively communicate with health care providers to improve patients' health.

Health-promoting lifestyles and cardio-metabolic risk factors among international students in South Korea.

This study examined the health-promoting lifestyles and cardio-metabolic risks among international students in Korea. This descriptive, cross-sectional study design enrolled a convenience sample of 118 international students at a university in Korea. Collected data included items from the Health-promoting Lifestyle Profile (II) scale and cardiovascular risk factors. The participants had a moderately health-promoting lifestyle (2.5 of 4). Men engaged in more physical activity than did women (p = .002). The most prevalent risk factor was elevated blood lipid profiles (26.3%), followed by overweight/obesity (25.4%), elevated blood pressure (17.8%), and elevated fasting glucose levels (5.1%). More than half of the participants (54.2%) had one or more cardiac risk factors, and these participants also scored lower in health-promoting lifestyle factors than other students (p = .034). Regular health check-ups are needed to identify the cardio-metabolic risks of international students. A university-based programme aimed at promoting healthy lifestyles could help prevent cardio-metabolic risks among international students.

Factors influencing evidence-based nursing utilization intention in Korean practice nurses.

The purpose of this study was to describe Korean nurses' perceptions, attitudes and utilization intention for evidence-based nursing (EBN), and to explore what factors influence utilization intention. We conducted a cross-sectional survey in 2012. Registered nurses directly involved in clinical practice were recruited at a medical centre in Korea. A total of 420 nurses completed a self-report questionnaire. Results showed that participants reported moderate scores regarding their perceptions and attitudes towards EBN, and rated themselves as higher than the median for utilization intention. Furthermore, this study revealed that perceptions of and attitudes towards EBN, occupational view and previous EBN education were significant factors affecting utilization intention. Nurse educators and managers should encourage nurses to have better attitudes towards EBN, help them be more satisfied with their work and provide them with appropriate education for EBN to establish evidence-based practice as a part of daily nursing care.

Prevalence of metabolic syndrome and cardiovascular risk level in a vulnerable population.

This study examined the prevalence of metabolic syndrome and the risk level of cardiovascular disease (CVD) in a vulnerable population of 407 subjects in Korea. This descriptive study was a part of the Tailed Health Visiting Service Program, using baseline data from public health centres in Suwon, Korea. The definition of metabolic syndrome was based on the National Cholesterol Education Program criteria, and risk of CVD was estimated according to the Framingham study equation. This study demonstrated that the prevalence of metabolic syndrome was 40.8% higher and the risk of CVD was significantly 3.1 times higher among those with metabolic syndrome than among those without it. Of those with metabolic syndrome, 50.6% overall and 81.1% of men had a high risk for CVD. These findings suggest a need to screen and prevent the risk of CVD in vulnerable populations with metabolic syndrome.

Effects of a community-based intervention on cardio-metabolic risk and self-care behaviour in older adults with metabolic syndrome.

This pilot study was performed to investigate the effects of a community-based intervention (CBI) on cardio-metabolic risk and self-care behaviour in 92 older adults with metabolic syndrome at public health centres in Suwon, Korea. A prospective, pretest and posttest, controlled, quasi-experimental design was used. The older adults in the intervention group participated in an 8-week intensive lifestyle counselling, whereas those in the control group received usual care. The mean (standard deviation) age of the participants was 71.4 (4.43) years ranging from 60 to 84, and 75.0% of the participants were female. The intervention group at 8 weeks showed significant reduction in waist circumference by -1.35 cm (P<0.001) and improved self-care behaviour (+5.17 score, P<0.05) and self-efficacy (+4.84 score, P<0.001) when compared with the control group. The percentages of those who successfully completed the targeted behavioural modification were 71.7% for exercise and 52.2% for dietary control in the intervention group at 8 weeks. This pilot study provided evidence of the beneficial impact of the CBI for Korean older adults with metabolic syndrome.

Patient-reported outcomes following stereotactic body radiation therapy for clinically localized prostate cancer.

BACKGROUND: Stereotactic body radiation therapy (SBRT) delivers high doses of radiation to the prostate while minimizing radiation to adjacent normal tissues. Large fraction sizes may increase the risk of functional decrements. Treatment-related bother may be more important to a patient than treatment-related dysfunction. This study reports on patient-reported outcomes following SBRT for clinically localized prostate cancer. METHODS: Between August 2007 and July 2011, 228 consecutive hormone-naïve patients with clinically localized prostate cancer were treated with 35-36.25 Gy SBRT delivered using the CyberKnife Radiosurgical System (Accuray) in 5 fractions. Quality of life was assessed using the American Urological Association Symptom Score (AUA) and the Expanded Prostate Cancer Index Composite (EPIC)-26. Urinary symptom flare was defined as an AUA score 15 or more with an increase of 5 or more points above baseline 6 months after treatment. RESULTS: 228 patients (88 low-, 126 intermediate- and 14 high-risk) at a median age of 69 (44-90) years received SBRT with a minimum follow-up of 24 months. EPIC urinary and bowel summary scores declined transiently at 1 month and experienced a second, more protracted decline between 9 months and 18 months before returning to near baseline 2 years post-SBRT. 14.5% of patients experienced late urinary symptom flare following treatment. Patients who experienced urinary symptom flare had poorer bowel quality of life following SBRT. EPIC scores for urinary bother declined transiently, first at 1 month and again at 12 months, before approaching pre-treatment scores by 2 years. Bowel bother showed a similar pattern, but the second decline was smaller and lasted 9 months to 18 months. EPIC sexual summary and bother scores progressively declined over the 2 years following SBRT without recovery. CONCLUSIONS: In the first 2 years, the impact of SBRT on urination and defecation was minimal. Transient late increases in urinary and bowel dysfunction and bother were observed. However, urinary and bowel function and bother recovered to near baseline by 2 years post-SBRT. Sexual dysfunction and bother steadily increased following treatment without recovery. SBRT for clinically localized prostate cancer was well tolerated with treatment-related dysfunction and bother comparable to conventionally fractionated radiation therapy or brachytherapy.

High-sensitivity detection of oxytetracycline using light scattering agglutination assay with aptasensor.

We present an aptamer-based biosensor (aptasensor) for rapid and high-sensitive detection of oxytetracycline (OTC) antibiotic in PBS inside a Y-channel PDMS microfluidic device. The detection was made by real-time monitoring of the agglutination assay of ssDNA aptamer-conjugated polystyrene latex microspheres with proximity optical fibers. The agglutination assay was performed with serially diluted OTC antibiotic solutions using highly carboxylated polystyrene particles of 920 nm diameter conjugated with OTC-binding ssDNA aptamer. Proximity optical fibers were used to measure the increase in 45° forward light scattering of the aggregated particles by fixing them around the viewing cell of the device with stable angle and distance to the detector. The detection limit was around 100 ppb for the current aptasensor system with the detection time less than 3 min.

A meta-analysis of aerobic exercise interventions for women with breast cancer.

The purpose of this meta-analysis was to examine the effectiveness of aerobic exercise interventions on cardiopulmonary function and body composition in women with breast cancer. Of 24 relevant studies reviewed, 10 studies (N = 588) met the inclusion criteria. The findings indicated that aerobic exercise significantly improved cardiopulmonary function as assessed by absolute VO2 peak (standardized mean difference [SMD] .916, p < .001), relative VO2 peak (SMD .424, p < .05), and 12-minute walk test ( SMD .502, p < .001). Similarly, aerobic exercise significantly improved body composition as assessed by percentage body fat (SMD -.890, p < .001), but body weight and lean body mass did not change significantly. Aerobic exercise during or after cancer adjuvant therapy seems to be an effective means of improving cardiopulmonary function and decreasing percentage body fat in women with breast cancer. Further studies are needed to examine the long-term benefits of aerobic exercise.