Background: Contact isolation (ie, patient isolation with contact precautions) has been frequently used for preventing healthcare-associated infections caused by epidemiologically important pathogens (eg, vancomycin-resistant enterococcus [VRE]) via direct or indirect contact with patients. Based on ineffective components of routine contact isolations (eg, fewer healthcare provider visits), some studies have reported an association between the likelihood of adverse events and contact isolation. Objective: Given no strong evidence for this association due to most studies’ invalid study designs and systematic misclassification, we compared adverse events between a VRE isolation cohort and a matched comparison cohort, using a propensity score matching cohort study design. Methods: This study was conducted at a 1,337-bed, tertiary-care, university-affiliated, Korean hospital equipped with a full electronic medical record (EMR) system for all patient records. With institutional review board approval, all relevant EMR records were extracted for the study period 2015–2017. All contact isolation information of VRE patients were confirmed through EMR manual review by 1 trained research nurse. For propensity score matching, risk factors for adverse events (ie, decubitus ulcer, fall, and cardiopulmonary resuscitation [CPR]) were selected based on literature reviews: length of stay, age, gender, diabetes mellitus, hypertension, albumin, Charlson comorbidity index, Braden scale score, and Hendrich II fall risk. For each VRE case, the 1:1 matched case was selected through the nearest neighbor matching with calculated propensity scores. The retrospective observation period was from the cohort entry date (ie, contact isolation start date) to the cohort exit date (ie, discharge or discontinue of contact isolation). A time-to-event analysis with a Cox proportional hazard model was conducted using SAS version 9.4 software. Results: Among the 98,527 inpatients (323 VRE positive; 98,204 VRE negative), the VRE cohort (N = 141 of 216, 65% of total VRE patients admitted to general wards without adverse event history before contact isolation) and the matched comparison (no isolation) cohort (N = 141, 0.1%) showed no differences in characteristic comparisons (Table 1). The Cox proportional hazard model was not applicable for CPR because no CPR case was available in the matched comparison cohort. The hazard ratios for adverse events showed no statistically significant difference for both cohorts: decubitus ulcer (hazard ratio [HR], 1.049; 95% CI, 0.328–3.352; fall (HR, 0.418; 95% CI, 0.051–3.349) (Table 2). Conclusions: Based on the full EMR records for 3 years, our propensity-score–matched cohort study reported no association between the likelihoods of adverse events and contact isolation.

Funding: This work was supported by the Collaborative Research Program of Medical Science and Nursing Science from Seoul National University College of Medicine (Grant no. 800-20180001 & 810-20180001).

Disclosures: None.

Genetic and environmental influences on age at menarche (AAM) have rarely been examined in Asian females. This study aimed to investigate the heritability of AAM in South Korean female twins. The AAM data from 1370 female twins (933 monozygotic [MZ] twins, 294 dizygotic [DZ] twins and 160 female members of opposite-sex DZ twins) born between 1988 and 2001 were analyzed. The age of the sample at the time of the assessment ranged from 16 to 28 years with a mean of 19.3 (SD = 2.2) years. The mean AAM in the total sample was 12.49 (SD = 1.41) years. Although the mean AAM decreased with increasing birth years, it levelled off in birth years 2000–2001. Maximum likelihood MZ and DZ twin correlations were 0.72 [95% CI (0.67, 0.76)] and 0.35 [95% CI (0.19, 0.50)], respectively. The results of model-fitting analysis indicated that the additive genetic and individual-specific environmental effects were 72% [95% CI (67%, 76%)] and 28% [95% CI (24%, 33%)], respectively. Neither nonadditive genetic nor shared environmental effects were significant.

Somatization is known to be more prevalent in Asian than in Western populations. Using a South Korean adolescent and young adult twin sample (N = 1754; 367 monozygotic male, 173 dizygotic male, 681 monozygotic female, 274 dizygotic female and 259 opposite-sex dizygotic twins), the present study aimed to estimate heritability of somatization and to determine common genetic and environmental influences on somatization and hwabyung (HB: anger syndrome). Twins completed self-report questionnaires of the HB symptoms scale and the somatization scale via a telephone interview. The results of the general sex-limitation model showed that 43% (95% CI [36, 50]) of the total variance of somatization was attributable to additive genetic factors, with the remaining variance, 57% (95% CI [50, 64]), being due to individual-specific environmental influences, including measurement error. These estimates were not significantly different between the two sexes. The phenotypic correlation between HB and somatization was .53 (p < .001). The bivariate model-fitting analyses revealed that the genetic correlation between the two symptoms was .68 (95% CI [.59, .77]), while the individual-specific environmental correlation, including correlated measurement error, was .41 (95% CI [.34, .48]). Of the additive genetic factors of 43% that influence somatization, approximately half (20%) were associated with those related to HB, with the remainder being due to genes unique to somatization. A substantial part (48%) of individual environmental variance in somatization was unrelated to HB; only 9% of the environmental variance was shared with HB. Our findings suggest that HB and somatization have shared genetic etiology, but environmental factors that precipitate the development of HB and somatization may be largely independent from each other.

According to the Sasang theory, humans can be categorized into one of the four Sasang constitution (SC) types. The four SC types are Tae-Yang (TY), Tae-Eum (TE), So-Yang (SY), and So-Eum (SE), which are determined mainly on the basis of anthropometric characteristics, personality, and the balance of the physiological functions of the major organ systems. There is a growing recognition in the complementary and alternative medicine area that SC types have the potential to be a useful scientific tool for the prevention, diagnosis, and treatment of diseases (Cooper, Evidence Based Complementary and Alternative Medicine, Vol. 6 (Suppl. 1), 2009, pp. 1–3). The main purposes of the present study are to estimate genetic and environmental influences on SC types, and to explore genetic and environmental correlations that affect phenotypic associations among the SC types. In total, 1,742 (365 monozygotic male, 173 dizygotic male, 675 monozygotic female, 271 dizygotic female, and 258 opposite-sex dizygotic) twins (mean age = 19.1 ± 3.1 year) completed a Sasang questionnaire. Univariate and multivariate model-fitting analyses were performed. Total (additive and non-additive) genetic influences were 71% for males and 81% for females in TE, 70% for males and 71% for females in SE, and 47% for both sexes in SY. Non-additive genetic effects were substantial, and shared environmental influences were negligible in most SC types. Multivariate model-fitting analysis revealed that non-additive genetic and individual-specific environmental correlations between TE and SE were -0.92 (95% CI [-0.89, -0.93]) and -0.62 (95% CI [-0.57, -0.68]), respectively. The corresponding estimates were -0.55 (95% CI [-0.48, -0.61]) and -0.44 (95% CI [-0.37, -0.51]) between TE and SY and 0.19 (95% CI [0.09, 0.29]) and -0.40 (95% CI [-0.32, -0.47]) between SE and SY. These results suggest that the phenotypic associations among SC types may be mediated by pleiotropic mechanism of genes.

The present study aimed to estimate heritability of Hwabyung (HB) symptoms in adolescent and young adult twins in South Korea. The sample included 1,601 twins consisting of 143 pairs of monozygotic male (MZM), 67 pairs of dizygotic male (DZM), 295 pairs of monozygotic female (MZF), 114 pairs of dizygotic female (DZF), and 117 pairs of opposite-sex dizygotic (OSDZ) twins and 129 twins with non-participating co-twins (mean age = 19.1 ± 3.1 years; range: 12–29 years). An HB symptom questionnaire was given to twins via a telephone interview. Consistent with the literature of HB, the mean level of HB was significantly higher in females than in males. Maximum likelihood twin correlations for HB were 0.31 (95% CI [0.16, 0.45]) for MZM, 0.19 (95% CI [-0.05, 0.41]) for DZM, 0.50 (95% CI [0.41, 0.58]) for MZF, 0.28 (95% CI [0.11, 0.44]) for DZF, and 0.23 (95% CI [0.05, 0.40]) for OSDZ twins. These patterns of twin correlations suggested the presence of additive genetic influences on HB. Model-fitting analysis showed that additive genetic and individual-specific environmental influences on HB were 44% (95% CI [37, 51]) and 56% (95% CI [49, 63]), respectively. Shared environmental influences were not significant. These parameter estimates were not significantly different between two sexes, and did not change significantly with age in the present sample, suggesting that genetic and environmental influences on HB in both sexes are stable across adolescence and young adulthood.

Bloodstream infection (BSI) occurred in 21 of 121 patients (17%) receiving venovenous extracorporeal membrane oxygenation within the median time of 6 days after initiation (interquartile range, 4–19 days). Longer duration of arterial catheterization and more blood transfusions were independently associated with BSI, which is associated with poor clinical outcomes.

Infect Control Hosp Epidemiol 2018;1–4

The phenotypic relationships between body mass index (BMI) and cold-heat patterns have been frequently reported, but the etiology of these relationships remains unknown. We previously demonstrated that the cold pattern (CP) and the heat pattern (HP) were heritable traits. In the present study, we explored underlying genetic and environmental structures of the relationships among BMI and the CP and the HP. Twins (N = 1,752) drawn from the South Korean twin registry completed a cold-heat pattern questionnaire via a telephone interview. The phenotypic correlations among the three phenotypes were moderate but significant. Cross-twin, cross-trait correlations among BMI and the CP and the HP were consistently greater in monozygotic than in dizygotic twins, suggesting the presence of genetic effects on the relationships between BMI and the two patterns. A trivariate Cholesky model was applied to the raw data. The results indicated that the phenotypic relationship between the HP and BMI was completely determined by common genetic influences, while the relationship between the CP and BMI was explained by both common genetic and common individual-specific environmental influences. The genetic correlation between the HP and the CP was not significant, suggesting that the two patterns may be genetically independent from each other. Genetic correlations were 0.31 between the HP and BMI, and -0.22 between the CP and BMI. The individual-specific environmental correlation was -0.22 between HP and CP, and between CP and BMI.

In traditional East Asian medicine, cold–heat patterns have been widely used in the diagnosis and treatment of patients suffering from various diseases. The present study aimed to estimate the heritability of cold–heat patterns. Trained interviewers administered a cold–heat pattern questionnaire to 1,753 twins (mean age = 19.1 ± 3.1 years) recruited throughout South Korea. Correlations for the cold pattern (CP) were 0.42 (95% CI [0.28, 0.54]) for monozygotic (MZ) males, 0.16 (95% CI [-0.08, 0.39]) for dizygotic (DZ) males, 0.40 (95% CI [0.30, 0.49]) for MZ females, 0.30 (95% CI [0.12, 0.45]) for DZ females, and 0.07 (95% CI [-0.11, 0.25]) for opposite-sex DZ twins. The corresponding twin correlations for the heat pattern (HP) were 0.38 (95% CI [0.24, 0.51]), -0.22 (95% CI [-0.43, 0.02]), 0.34 (95% CI [0.24, 0.43]), 0.21 (95% CI [0.03, 0.37]), and 0.08 (95% CI [-0.10, 0.26]), respectively. These patterns of twin correlations suggested significant genetic effects on the HP and the CP. Model-fitting analysis revealed that heritability estimates in both sexes were 40% (95% CI [38, 42]) for the CP and 33% (95% CI [25, 42]) for the HP, with the remaining variances attributable to unique environmental variances. These estimates did not vary significantly with age during adolescence and young adulthood.

The junction resistance control of conducting networks is a crucial factor for high performance of the network-structured conducting film. Here, we show that silver nanowire (AgNW) networks can be stabilized by using single-walled carbon nanotubes (SWCNTs) which were functionalized with 2-ureido-4[1H]pyrimidinone (UHP) moieties. UHP-modified SWCNTs allowed us to fabricate AgNW suspension containing SWCNTs without adding additional dispersant molecules. The stabilization of AgNW networks was achieved by minimizing the joule heating at the NW-NW junction assisted by in-situ interconnection with the work function modulated SWCNTs. We propose that the electrical transportation pathway was modulated by the SWCNTs through the SWCNT-AgNW junctions, which results in a relatively lower junction resistance than the NW-NW junction in the network film.

Induction of mutations using chemical mutagens has proved to be a useful tool in crop improvement and has advantages over transgenic approaches in view of legislative restrictions and intellectual property. Among the chemical mutagens, ethyl methanesulfonate (EMS) has been widely used to generate novel traits. In this study, we constructed an EMS mutant population consisting of 3945 M2 mutant lines using a Korean landrace of Capsicum annuum ‘Yuwol-cho’. In total, 1480 M2 mutant lines were evaluated for novel traits. The mutant lines showed phenotypic variations such as plant growth (small size and dwarfism), development of leaves (variegation, colour and morphological changes), flowers (inflorescence, morphological and organ colour changes), and fruits (morphological and colour changes). Most of these mutant phenotypes were inherited recessively. Many of the mutant phenotypes were unique in pepper, while some were similar to those of known mutants in other plant species. These mutant lines will be useful for the study of gene function in C. annuum.

Colloidal dispersion of nanocarbon (NC) materials in dilute solutions or pastes is prerequisite for applications of NC-based electrodes from flexible electronics and flexible conducting fibers to electrochemical devices. Here, we show a straightforward method for fabricating NC suspensions with >10% weight concentrations in absence of organic dispersants. The method involves introducing supramolecular quadruple hydrogen bonding motifs into the NC materials without sacrificing the electrical conductivity.