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Abstract Background Long-term exposure to PM2.5 has been linked to increased mortality risk. However, limited studies have examined the potential modifying effect of community-level characteristics on this association, particularly in Asian contexts. This study aimed to estimate the effects of long-term exposure to PM2.5 on mortality in South Korea and to examine whether community-level deprivation, medical infrastructure, and greenness modify these associations. Methods We conducted a nationwide cohort study using the National Health Insurance Service-National Sample Cohort. A total of 394,701 participants aged 30 years or older in 2006 were followed until 2019. Based on modelled PM2.5 concentrations, 1 to 3-year and 5-year moving averages of PM2.5 concentrations were assigned to each participant at the district level. Time-varying Cox proportional-hazards models were used to estimate the association between PM2.5 and non-accidental, circulatory, and respiratory mortality. We further conducted stratified analysis by community-level deprivation index, medical index, and normalized difference vegetation index to represent greenness. Results PM2.5 exposure, based on 5-year moving averages, was positively associated with non-accidental (Hazard ratio, HR: 1.10, 95% Confidence Interval, CI: 1.01, 1.20, per 10 µg/m3 increase) and circulatory mortality (HR: 1.22, 95% CI: 1.01, 1.47). The 1-year moving average of PM2.5 was associated with respiratory mortality (HR: 1.33, 95% CI: 1.05, 1.67). We observed higher associations between PM2.5 and mortality in communities with higher deprivation and limited medical infrastructure. Communities with higher greenness showed lower risk for circulatory mortality but higher risk for respiratory mortality in association with PM2.5. Conclusions Our study found mortality effects of long-term PM2.5 exposure and underlined the role of community-level factors in modifying these association. These findings highlight the importance of considering socio-environmental contexts in the design of air quality policies to reduce health disparities and enhance overall public health outcomes.

Damage to the intestinal barrier causes intestinal inflammation, which could lead to the development of gastrointestinal diseases. Nut oils contain an abundance of unsaturated fatty acids, which are responsible for most of the bioactivities of nut oils. Here, the protective effect of four nut oils on the intestinal epithelial barrier was confirmed using Caco-2 cells damaged by tumor necrosis factor-α/interferon-γ treatment. Nut oils effectively increased transepithelial electronic resistance and lowered paracellular fluorescein isothiocyanate-dextran permeability in damaged Caco-2 cells. Furthermore, the nut oils inhibited the pro-inflammatory cytokine production of interleukin-6, which was induced by the inflammatory response. In particular, walnut oil effectively improved tight junction protein (occludin and zonula occludens-1) expression and distribution in damaged Caco-2 cells. In conclusion, our findings suggest that nut oils are promising candidates for impaired intestinal barrier protection.

Abstract Transition metal dichalcogenides have attracted renewed interest for use as thermoelectric materials owing to their tunable bandgap, moderate Seebeck coefficient, and low thermal conductivity. However, their thermoelectric parameters such as Seebeck coefficient, electrical conductivity, and thermal conductivity are interdependent, which is a drawback. Therefore, it is necessary to find a way to adjust one of these parameters without affecting the other parameters. In this study, we investigated the effect of helium ion irradiation on MoSe2 thin films with the objective of controlling the Seebeck coefficient and electrical conductivity. At the optimal irradiation dose of 1015 cm−2, we observed multiple enhancements of the power factor resulting from an increase in the electrical conductivity, with slight suppression of the Seebeck coefficient. Raman spectroscopy, X-ray diffraction, and transmission electron microscopy analyses revealed that irradiation-induced selenium vacancies played an important role in changing the thermoelectric properties of MoSe2 thin films. These results suggest that helium ion irradiation is a promising method to significantly improve the thermoelectric properties of two-dimensional transition metal dichalcogenides. Graphical Abstract Effect of He+ irradiation on thermoelectric properties of MoSe2 thin films.

Menopause is defined as the end of a woman’s menstrual cycle sustained over 12 months and caused by reduced secretion of estrogen and progesterone in ovaries. These hormonal changes lead to menopausal symptoms, including hot flushes, difficulty sleeping, depression and osteoporosis. Hormone replacement therapy, such as the administration of estrogen, estrogen plus progesterone and phytoestrogen, and nonhormonal therapy, including hormone reuptake inhibitors, are used to manage menopausal symptoms. In this study, the estrogenic acidity of Ecklonia cava (E. cava) and the therapeutic effect of E. cava on depression and osteoporosis symptoms in an ovariectomized mouse model of menopause were investigated. The estrogenic activity was increased by treatment with E. cava extract (ECE). In an evaluation of the antidepressive effect of the extract, ECE treatment significantly decreased the duration of depressive immobility in the tail suspension test and forced swim test. The levels of the neurotransmitters serotonin and norepinephrine were recovered by ECE treatment. In an antiosteoporotic evaluation, bone microarchitectures and trabecular bone mineral density were improved by ECE treatment. Furthermore, the serum levels of C-terminal telopeptide (CTX) and receptor activator of nuclear factors κB ligand (RANKL) were decreased, and osteoprotegerin (OPG) was upregulated by ECE treatment. Taken together, these results indicate that E. cava could ameliorate menopausal depression and osteoporosis and be used for managing these symptoms.

Obesity is a serious health problem worldwide and can lead to the development of metabolic syndromes, including hypertension, type 2 diabetes, and hyperglycemia. Therefore, we investigated the effect of an ethanol extract of Sargassum horneri (SH) on high-fat diet (HFD)-induced obese mice. To determine whether SH has an anti-obesity effect, C57BL/6 mice fed with HFD containing SH (100 and 300 mg/kg) were investigated for 7 weeks. The administration of SH significantly reduced body weight, white adipose tissue weight, fat accumulation in the liver, and white adipose tissues by increasing the mRNA expression of mitochondrial uncoupling protein 1 and mitochondrial uncoupling protein 3 in brown adipose tissues. Additionally, serum triglyceride, cholesterol, and leptin levels were significantly decreased in the mice administered SH compared with those of the HFD group. Our results showed that the ethanol extract of SH may be used as a functional food for treating obesity.

Objectives To understand a 20-year trend of gender-specific smoking prevalence among adults in South Korea.Design Age-period-cohort analysis using the intrinsic estimator method was applied to examine the separate contribution of age, period and cohort effect on smoking prevalence. The Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA) framework was used to explain the observed smoking trends by mapping potential determinants and to address policy implications.Setting General adult population in South Korea.Participants 34 828 men and 43 632 women who aged 19–78 years, were not currently pregnant and were without a prior diagnosis of cardiovascular disease or cancer.Outcome measures Gender-specific current smoking prevalence using the 1998–2017 Korea National Health and Nutrition Examination Survey.Results Our results showed gender-specific age and birth cohort effects. More specifically, the smoking prevalence peaked at their mid-20s (prevalence rate ratio (PRR): 1.54, 95% CI: 1.49 to 1.59) and cohort born in 1959–1963 (PRR: 1.63, 95% CI: 1.57 to 1.70) and then decreased in men. On the other hand, in women, the smoking prevalence consistently increased until their mid-40s (PRR: 1.53, 95% CI: 1.27 to 1.84) and in recent birth cohort groups (PRR in 1994–1998 cohort: 1.55, 95% CI: 1.13 to 2.13). The period effects declined from 1998−2002 to 2003–2007, following increasing fluctuations in both genders. The smoking-DPSEEA framework showed the absence of policy actions to target female smokers and emphasised a proactive approach that tackles the upstream causes for smoking in women.Conclusions Men and women are clearly in different phases of the smoking epidemic in Korean population, and gender-tailored policies should be implemented.

Contrary to expectations that the coronavirus pandemic would terminate quickly, the number of people infected with the virus did not decrease worldwide and coronavirus-related deaths continue to occur every day. The standard COVID-19 diagnostic test technique used today, PCR testing, requires professional staff and equipment, which is expensive and takes a long time to produce test results. In this paper, we propose a feature set consisting of four features: MFCC, Δ2-MFCC, Δ-MFCC, and spectral contrast as a feature set optimized for the diagnosis of COVID-19, and apply it to a model that combines ResNet-50 and DNN. Crowdsourcing datasets from Cambridge, Coswara, and COUGHVID are used as the cough sound data for our study. Through direct listening and inspection of the dataset, audio recordings that contained only cough sounds were collected and used for training. The model was trained and tested using cough sound features extracted from crowdsourced cough data and had a sensitivity and specificity of 0.95 and 0.96, respectively.

The prevalence of osteoporotic fracture is increasing globally due to rapid population growth and aging. Current evidence suggests adverse impacts of air pollution on bone mineral density loss and osteoporosis, but population-based evidence for the associations between fine particulate matter (particulate matter no larger than 2.5 μ m in diameter [PM _2.5 ]) and osteoporotic fracture is limited due to the small number of studies. This longitudinal study assessed the associations between long-term exposure to PM _2.5 and osteoporotic fracture incidence in adults aged ⩾40 years, who enrolled in the National Health Insurance Service-National Sample Cohort data in 2002–2019 in South Korea. A time-varying moving window of past exposures of PM _2.5 up to ten past years was estimated for participants’ residential addresses using modeled PM _2.5 . We used Cox proportional hazard models to estimate hazard ratios (HRs) of time-variant moving concentrations of PM _2.5 exposure and osteoporotic fracture. The Cox models calculated HRs for an interquartile range (IQR) increase in PM _2.5 exposure, adjusting for age, sex, body mass index, health behaviors, medications, disease history, income, and urbanicity. We assessed 161 831 participants over 993 104 person-year of follow-up. Results suggested linear and positive exposure-response associations for past PM _2.5 exposure in the prior four years or more. The IQR increase in 5-year moving average PM _2.5 was significantly associated with increased osteoporotic risk (HR = 1.079, 95% CI: 1.001, 1.164). The HRs were significant in women (1.102, 95% CI: 1.011, 1.200) and the subset of women aged 50–74 years (1.105, 95% CI: 1.005, 1.214) but not in men overall or by age groups. The association was not significantly different by income, physical activities, urbanicity, or diet. Overall, long-term PM _2.5 exposure was associated with increased osteoporotic fracture risks in Korean adults, especially women.

Background and purpose: Spontaneous intracranial hypotension (SIH) is a significant, treatable cause of postural headache, although the best diagnostic approach to diagnosing cerebrospinal fluid (CSF) leaks remains uncertain. The aim of this study is to evaluate the most common techniques used to diagnose leaks, the most frequent leak sites, and epidural patch treatment characteristics. Materials and methods: We retrospectively reviewed the electronic medical records and radiographic findings of 30 patients clinically treated for SIH at a single university hospital between January 2015 and December 2016. Clinical symptoms, imaging findings and epidural patch details including dates, injection location, and amount of blood/fibrin injected were recorded. Results: Of 30 SIH patients identified, 11/30 (37%) had a localized leak and 14/30 (47%) had a non-localized leak. The first modality to identify the leak was most commonly CT myelogram (17/25, 68%), followed by MRI spine (6/25, 24%) and MRI myelogram (2/25, 8%). The most frequent leak sites were C7–T1, C5–C6, and T10–T11 in decreasing order. All patients underwent CT-guided epidural patch, averaging 2.3 procedure sessions, 3.4 injection sites, and 7.8 mL of injectate per site. Conclusion: Spinal CSF leak remains a challenging diagnosis, with CT myelography most frequently confirming the diagnosis, supplemented by spine MRI and MRI myelography. Patients frequently require multiple injections at multiple sites, and physicians and patients should be aware of the possible need for repeat treatments. Given the most common sites of leak, empiric blood patch at the cervicothoracic or thoracolumbar junction should be considered if no definitive leak is identified. Keywords: Headache, Cerebrospinal fluid leak, Blood patch

Advanced glycation end-products (AGEs) such as methylglyoxal (MGO) play a vital role in the pathogenesis of nephropathy, a diabetic complication. In the present study, we evaluated the anti-glycation and renal protective properties of Ishige okamurae extract (IOE) against AGE-induced oxidative stress. HPLC analysis confirmed that bioactive phlorotannins such as diphlorethohydroxycarmalol and ishophloroglucin A are predominantly present in IOE. IOE showed strong anti-glycation activities via inhibition of AGE formation, inhibition of AGE–protein cross-linking, and breaking of AGE–protein cross-links. In addition, in vitro studies using mesangial cells demonstrated that IOE effectively suppressed intracellular reactive oxygen species production, intracellular MGO accumulation, and apoptotic cell death by MGO-induced oxidative stress, in addition to regulating the expression of proteins involved in the receptor for AGEs and nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response elements (ARE) signaling pathways. Therefore, IOE can serve as a natural therapeutic agent for the management of AGE-related nephropathy.

Curcuma longa L. (turmeric) has been used as a functional food material, but other parts of it such as leaves are wasted as a byproduct. This work concentrated on developing turmeric leaves as a functional food material by establishing its optimal extraction condition. Response surface methodology was applied to optimize turmeric leaf extraction conditions. Turmeric leaves were pulled out with water and ethanol (10, 30, and 50%). Then, total phenolic compound content, total flavonoid content, and radical-scavenging activity of each extract were quantified to confirm the optimal extracting solvent. According to the results, water was the most efficient solvent to extract antioxidant contents such as total phenolic compounds (3.65 ± 0.02 mg GAE/g) and flavonoids (4.99 ± 0.17 mg QCE/g) content. Radical-scavenging activity was also higher in water extract compared with others such as DPPH (51.10 ± 2.29%), H2O2 (25.39 ± 2.69%), and ABTS (91.08 ± 0.15%). Central composite design was applied to confirm the effect of independent variables such as temperature (X1) and time (X2) to the yield (Y1). After conducting experiments, the extraction condition was established as 150 min with 1 : 25 ratio at 85°C with a 15.58% yield. Proximate compositions of the extract were determined to suggest background data for further research. In conclusion, this study confirmed the antioxidant property of turmeric leaves and developed the optimal extraction condition of the leaves to promote its application in food industry as a new food source.

Access to urban greenspace has many benefits such as improved health and social cohesion. If access differs by population, these benefits make access to greenspace an environmental justice issue, but little is known regarding accessibility of parks among different sub-groups in Seoul, South Korea. We explored potential socioeconomic inequities for access to parks in Seoul measuring two park provision metrics: total park area per capita (TPPC), and park accessibility index determined by size and proximity of parks. We assessed correlations between a deprivation index for the 25 Gus (administrative unit equivalent to the US borough) and each park provision metric. Regression analyses were applied for the associations between eight socioeconomic indicators of the 424 Dongs (equivalent to the US neighborhood) and each park provision metric. An interquartile range (IQR) increase in percent elderly (⩾65 years) (3.2%) was significantly associated with larger TPPC (1.6 m ^2 /person, 95% CI: 0.8, 2.4). Park accessibility index was associated with more socioeconomic variables than was TPPC. An IQR increase in percent elderly and divorce rates (1.2/1000 population) was associated with increased park accessibility by 3571 km (95% CI: 1103, 6040) and decreased park accessibility by 1387 (95% CI: −2706, −67), respectively. An IQR increase in percentage of the population receiving social low-income support aid (2.2%) was associated with increased park accessibility (reflecting park size and proximity of parks) of residential parks near residential areas by 1568 (95% CI: 15, 3120). Results suggest higher park access for socioeconomically disadvantaged regions. Findings indicate that measures of detailed park access considering spatial proximity and park size may more accurately measure park inequity compared to more basic metrics (e.g. TPPC), which may bias estimation of park inequity by capturing only one characteristic of parks. Detailed park measures should be considered in urban planning and health studies of greenspace.

Oxidative stress, caused by the excessive production of reactive oxygen species (ROS), results in cellular damage. Therefore, functional materials with antioxidant properties are necessary to maintain redox balance. Turmeric leaves (Curcuma longa L. leaves; TL) are known to have antioxidant properties, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), and Hydrogen peroxide (H2O2) radical scavenging activity in several studies. The antioxidant effects of TL come from distinct bioactive compounds, such as curcumin, total phenolic compounds, and flavonoids. Therefore, in this study, the antioxidant effects of a water extract of TL (TLE) against H2O2 treatment were assessed in vitro Vero cells and in vivo zebrafish models. The intracellular ROS generation and the proportion of sub-G1 phase cells were evaluated in H2O2- or/and TLE-treated Vero cells to measure the antioxidant activity of TLE. TLE showed outstanding intracellular ROS scavenging activity and significantly decreased the proportion of cells in the sub-G1 phase in a dose-dependent manner. Furthermore, cell death, ROS generation, and lipid peroxidation in the H2O2-treated zebrafish model were attenuated as a consequence of TLE treatment. Collectively, the results from this study suggested that TLE may be an alternative material to relieve ROS generation through its antioxidant properties or a suitable material for the application in a functional food industry.

Doping two-dimensional (2D) semiconductors beyond their degenerate levels provides the opportunity to investigate extreme carrier density-driven superconductivity and phase transition in 2D systems. Chemical functionalization and the ionic gating have achieved the high doping density, but their effective ranges have been limited to ~1 nm, which restricts the use of highly doped 2D semiconductors. Here, we report on electron diffusion from the 2D electride [Ca2N]+·e- to MoTe2 over a distance of 100 nm from the contact interface, generating an electron doping density higher than 1.6 × 1014 cm-2 and a lattice symmetry change of MoTe2 as a consequence of the extreme doping. The long-range lattice symmetry change, suggesting a length scale surpassing the depletion width of conventional metal-semiconductor junctions, was a consequence of the low work function (2.6 eV) with highly mobile anionic electron layers of [Ca2N]+·e-. The combination of 2D electrides and layered materials yields a novel material design in terms of doping and lattice engineering. [ABSTRACT FROM AUTHOR]

The Chronic Obstructive Pulmonary Disease (COPD) is characterized by an airflow limitation, which can cause muscu-loskeletal and exercise dessaturation, this factors can contribute for the alterations in the balance. So the aim of this research was to evaluate the oxygen desaturation effects on balance in patients with COPD. Was evaluated 6 subjects (3 menand 3 women) with 64,83±7,73 years old and clinical and functional diagnosis of COPD. All the subjects were submitted to anamnesis, spirometry, 6 minutes walk test (6MWT), Incremental Shuttle Walking Test (ISWT) and Stairs Climbing Test (SCT) with the purpose to detect possible dessaturations. The patients that desaturated were submitted to an Ergometric Test on the treadmill and Static Balance Evaluationon a strength platform. The oxygen saturation before and after the exercise test was compared using the paired t Test and the measures of balance before and after the desaturation were analyzed by Friedman's Test to repeated measures (p>0,05). The evaluated subject presented pulmonary function compatible with airflow obstruction (Forced Expiratory Volume on the first minute - FEV1 75,16±32,91% and the relation FEV1/FVC 64,67±6,42%) and desaturation in all field tests, except the 6MWT. The variables obtained on the strength platform do not show significant difference in the moments of this study. Thus, we concluded that there was no balance alteration in patients with desaturation after stress test. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD), which is characterized by >5% deposition of triglycerides in hepatocytes, is often referred as a major risk factor for obesity, type 2 diabetes, and hypertension. We investigated the hepatoprotective effect of whole soybean embryos containing bioactive substances such as isoflavones and soyasaponins. For this study, mice were randomly allocated into four groups that were fed different diets for 10 weeks: normal diets and high-fat and high-cholesterol diets (HD), and HD with 10% or 20% soybean embryo powder (10SE-HD and 20SE-HD). Hepatic superoxide dismutase and glutathione peroxidase activity of the experimental groups increased during the period of the study (P < .05). Hepatic mRNA expressions of tumor necrosis factor α, nuclear factor (erythroid-derived 2)-like 2, and Caspase 3 were decreased when soybean embryos were increased in the mice's diets. Both of the soybean embryo-treated groups showed significantly decreased serum and liver triglyceride and total cholesterol. Adiponectin, AMP-activated protein kinase (AMPK) α, hydroxymethylglutaryl-CoA reductase, sterol regulatory element-binding protein-1c, fatty acid synthase, and apolipoprotein B mRNA expressions were decreased in the mice that were fed soybean embryos. We suggest that the regular supplementation of soybean embryos might be a useful treatment for preventing NAFLD and associated complications through upregulation of adiponectin-mediated AMPKα pathway parameters, which are implicated in antioxidant, anti-inflammatory, and lipid metabolism activities. [ABSTRACT FROM AUTHOR]

Artificial van der Waals heterostructures with two-dimensional (2D) atomic crystals are promising as an active channel or as a buffer contact layer for next-generation devices. However, genuine 2D heterostructure devices remain limited because of impurity-involved transfer process and metastable and inhomogeneous heterostructure formation. We used laser-induced phase patterning, a polymorph engineering, to fabricate an ohmic heterophase homojunction between semiconducting hexagonal (2H) and metallic monoclinic (1T') molybdenum ditelluride (MoTe2) that is stable up to 300°C and increases the carrier mobility of the MoTe2 transistor by a factor of about 50, while retaining a high on/off current ratio of 106. In situ scanning transmission electron microscopy results combined with theoretical calculations reveal that the Te vacancy triggers the local phase transition in MoTe2, achieving a true 2D device with an ohmic contact. [ABSTRACT FROM AUTHOR]

To control excessive utilization of medical care services by Medical Aid beneficiaries (MABs), the Korean government has introduced the Designated Practice Scheme (DPS, July 2007). The purpose of this study was to assess the primary care quality of the DPS using the Korean Primary Care Assessment Tool (K-PCAT). Data were collected from the survey (2008-2009) of MABs who had to designate a community clinic as the first contact practice obligatorily in one district of Seoul. Among all eligible (n=164), we analyzed the data of 154 beneficiaries, excluding those who did not meet the K-PCAT criteria of a usual source of care. Primary care quality under the DPS was poor (58.1 points) on a 100-point scale, compared with those previously studied under the Korean health care system. More seriously it was very poor (48.9 points) in MABs without intention to continue participation in the DPS, who were 50% of all participants. Among 5 domains of the K-PCAT, comprehensiveness (44.7 points) and coordination (39.3 points) were lower in score than other domains, comparable to previous studies, representing the reality of primary care in South Korea. Primary care quality was better in MABs using primary care practices including general practice, family medicine, and internal medicine instead of other specialty practice groups (60.2 vs. 53.9 points, P=0.015), and in MABs with longer duration (⩾3 vs. <3 years) since the first visit (59.7 vs. 51.9 points, P=0.010). These patterns were maintained after multivariate analysis, controlling for confounding variables. This research suggests that a complete overhaul of the scheme itself, such as the introduction of pay-for-performance method, etc., is necessary to improve primary care quality of the DPS. [ABSTRACT FROM AUTHOR]

Rhythmic auditory cueing (RAC) can improve gait parameters in neurological disorders such as Parkinson's disease and stroke. However, there is a lack of research on the effects of RAC in patients with atypical parkinsonian disorders (APD). Using a smartphone metronome application, we aimed to investigate the immediate effects of RAC in patients with clinically diagnosed APD, namely Progressive Supranuclear Palsy (PSP-Richardson Syndrome and other variants, PSP-nonRS), Corticobasal Syndrome (CBS), Multiple System Atrophy (MSA), and Dementia with Lewy Bodies (DLB). A total of 46 APD participants (25 PSP, 9 CBS, 8 MSA and 4 DLB; age: mean = 70.17, standard deviation = 7.15) walked at their preferred pace for 2 min without any rhythmic auditory cueing (RAC). Participants then walked the same path for another 2 min with RAC set at a tempo 10% faster than the baseline cadence of each participant. After a 10–15-min break, participants walked the same path for another 2 min without RAC to observe for carryover effects. Gait parameters [cadence (steps/minute), gait velocity (meters/minute), and stride length (centimeters)] were collected at baseline, during RAC, and post-RAC. There was a significant improvement in cadence in all participants from baseline to during RAC and post-RAC (corrected p-values = 0.009 for both). Gait velocity also improved from baseline to during RAC and post-RAC in all participants, although this improvement was not significant after correcting for multiple comparisons. The changes in cadence and gait velocity were most pronounced in PSP. In addition, our exploratory analysis showed that the cadence in the suspected TAU group (PSP+CBS) showed a significant improvement from baseline to during RAC and post-RAC (corr. p-value = 0.004 for both). This pilot study using short-term RAC in APD patients demonstrated improvements in cadence and velocity. There is an urgent need for effective gait rehabilitation modalities for patients with APD, and rhythmic cueing can be a practical and useful intervention to improve their gait pattern.

Background: While considerable evidence has been produced showing a link between nursing characteristics and patient outcomes in the U.S. and Europe, little is known about whether similar associations are present in South Korea. Objective: To examine the effects of nurse staffing, work environment, and education on patient mortality. Methods: This study linked hospital facility data with staff nurse survey data (N = 1024) and surgical patient discharge data (N = 76,036) from 14 high-technology teaching hospitals with 700 or more beds in South Korea, collected between January 1, 2008 and December 31, 2008. Logistic regression models that corrected for the clustering of patients in hospitals were used to estimate the effects of the three nursing characteristics on risk- adjusted patient mortality within 30 days of admission. Results: Risk-adjusted models reveal that nurse staffing, nurse work environments, and nurse education were significantly associated with patient mortality (OR 1.05, 95% CI 1.00-1.10; OR 0.52, 95% CI 0.31-0.88; and OR 0.91, CI 0.83-0.99; respectively). These odds ratios imply that each additional patient per nurse is associated with an 5% increase in the odds of patient death within 30 days of admission, that the odds of patient mortality are nearly 50% lower in the hospitals with better nurse work environments than in hospitals with mixed or poor nurse work environments, and that each 10% increase in nurses having Bachelor of Science in Nursing Degree is associated with a 9% decrease in patient deaths. Conclusions: Nurse staffing, nurse work environments, and percentages of nurses having Bachelor of Science in Nursing Degree in South Korea are associated with patient mortality. Improving hospital nurse staffing and work environments and increasing the percentages of nurses having Bachelor of Science in Nursing Degree would help reduce the number of preventable in-hospital deaths. [ABSTRACT FROM AUTHOR]