Aging and Fall Risk: Treadmill Based Perturbation Training

Slip-related falls cause severe consequences such as hip fractures and traumatic brain injuries, which can lead to prolonged hospitalization or even death in older adults. These fall-related injuries lead to a loss of mobility, causing psychological problems such as social isolation and even depression. Therefore, it is crucial to understand the age-related changes that result in falls and develop effective fall-prevention paradigms in older adults. The studies in this dissertation examined the age-related changes in the gait speed in relation to dynamic stability, which is a well-established fall risk predictor in older adults. In addition, this dissertation used a treadmill-based perturbation training paradigm in order to examine its effects on dynamic stability. Furthermore, participants were subjected to an overground slip to examine the generalization of the learned skill from treadmill-based perturbation training depending on the level of threat dosage (i.e., intensity, slip distance) and practice dosage (i.e., repetition). The study in this dissertation found that older adults, especially over the age of 85, walked significantly slower and demonstrated lower dynamic stability than those with ages below 85 years. Also, the study in this dissertation found that treadmill slip-perturbation training has a positive effect on reducing slip-related falls. Treadmill slip-perturbation training has the advantage of adjusting the training profile, thereby helping modulate the intensity and repetition depending on the health status of the older adult. Owing to the cost and space effectiveness associated with the treadmill as compared to the traditional overground walkway, such equipment can be easily translated into rehabilitation clinics. Therefore, treadmill slip-perturbation training could be quite suitable for clinical settings designed to help community-dwelling older adults improve their reactive balance and reduce their fall rate

Visible-Light-Driven Silver-Catalyzed One-Pot Approach: A Selective Synthesis of Diaryl Sulfoxides and Diaryl Sulfones

An efficient one-pot approach for the synthesis of diaryl sulfoxides and diaryl sulfones using aryl thiols and aryl diazonium salts was developed. The use of a visible-light-driven silver catalysis and the subsequent singlet-oxygen-induced oxidation enabled selective synthesis of sulfoxides and sulfones in the absence of a photocatalyst. The reactions were carried out under mild reaction conditions; the desired products were obtained under air atmosphere at room temperature

Nationwide Seropositivity of Hepatitis A in Republic of Korea from 2005 to 2014, before and after the Outbreak Peak in 2009

<div><p>Background/Aims</p><p>The epidemiologic shift of hepatitis A virus (HAV) infection in the South Korean population resulted in a peak outbreak of hepatitis in 2009. The aim of this study was to clarify the seropositivity of anti-HAV antibody (anti-HAV) and its demographic characteristics before and after the peak outbreak from 2005 to 2014.</p><p>Methods</p><p>This retrospective study analyzed the anti-HAV data of all individuals from 1,795 medical institutions referred to a major central laboratory from January 2005 through December 2014, as a sentineal tool for monitoring annual variation of anti-HAV positivity. The prevalence of anti-HAV was adjusted for age and area with the standard population based on the 2010 Census data.</p><p>Results</p><p>A total of 424,245 individuals were included in this study. The overall age-adjusted anti-HAV prevalence decreased from 65.6% in 2005 to 62.2% in 2014. During the 10-year period, the seroprevalence continuously decreased in persons aged 30 to 39 years (69.6% to 32.4%) and those aged 40 to 49 years (97.9% to 79.3%) due to the cohort effect. In contrast, it increased in persons aged 10 to 19 years (15.4% to 35.2%), while it was the lowest (8.7%) in 2010 before rebounding to 20.2% in 2014 in persons aged 20 to 29 years due to a vaccination effect.</p><p>Conclusion</p><p>Although the HAV vaccination rate increased, the anti-HAV seropositivity in South Korea decreased from 65.6% to 62.2% in this study population. In particular, the immunity of young adults was still low, and an outbreak of HAV is possible in the near future. Therefore, continuous monitoring and optimal preventive measures to prevent future outbreaks should be considered.</p></div

Characteristics of study population.

<p>Characteristics of study population.</p

Age-specific seroprevalence of anti-HAV adjusted by area and gender from 2005 to 2014.

<p>Age-specific seroprevalence of anti-HAV adjusted by area and gender from 2005 to 2014.</p

Changes of seroprevalence of anti-HAV according to age group from 2005 to 2014.

<p>Changes of seroprevalence of anti-HAV according to age group from 2005 to 2014.</p

MOESM1 of Are high nurse workload/staffing ratios associated with decreased survival in critically ill patients? A cohort study

Additional file 1: Figure S1. Directed acyclic graph. Assumptions made in the workload/staffing ratio threshold and hospital mortality relationship to identify the set of variables needed for confounding adjustment

Rational Design for the Controlled Aggregation of Gold Nanorods <i>via</i> Phospholipid Encapsulation for Enhanced Raman Scattering

This study describes a procedure that found a balance between the ability of polymer-stabilized nanorods (NRs) to self-assemble and the creation of narrow gaps to make reproducibly bright surface-enhanced Raman scattering (SERS) nanorod dimers. NRs were end-functionalized with polymers, which enabled end-to-end self-assembly of NR chains and control over inter-rod separation through polymer molecular weight (MW). We found a way to quench the self-assembly, by phospholipid encapsulation, reducing the polydispersity of the aggregates while rendering them water-soluble. This reduction in polydispersity and preferential isolation of short-chain nanorod species is important for maximizing SERS enhancement from nanorod chains. We prepared NR aggregates that exhibit ∼5–50 times greater SERS intensity than isolated rods (and ∼750× greater than bare dye) depending on inter-rod separation, when using Oxazine 725 reporter molecules. Colloidal stability of NR aggregates and temporal stability of the SERS signal in water were observed for 110 days. With enhanced SERS intensity, water solubility, and stability, these NR aggregates are promising optical probes for future biological applications

Enantioselective Annulations for Dihydroquinolones by in Situ Generation of Azolium Enolates

A convergent, catalytic asymmetric formal [4 + 2] annulation for the synthesis of dihydroquinolones has been developed. Carboxylic acids can be employed as precursors to NHC enolates through an in situ activation strategy. Simultaneous generation of a reactive aza-<i>o</i>-quinone methide under the basic conditions employed for NHC generation leads to a dual activation approach

Prevalence of potential <i>E. coli</i> pathotypes EPEC, STEC, and EHEC among phylogenetic groups.

<p>Prevalence of potential <i>E. coli</i> pathotypes EPEC, STEC, and EHEC among phylogenetic groups.</p