The purification, amino acid sequence, and two-dimensional 1H NMR results are reported for the rubredoxin (Rd) from the hyperthermophilic archaebacterium Pyrococcus furiosus, an organism that grows optimally at 100 degrees C. The molecular mass (5397 Da), iron content (1.2 +/- 0.2 g-atom of Fe/mol), UV-vis spectrophotometric properties, and amino acid sequence (60% sequence identity with Clostridium pasteurianum Rd) are found to be typical of this class of redox protein. However, P. furiosus Rd is remarkably thermostable, being unaffected after incubation for 24 h at 95 degrees C. One- and two-dimensional 1H nuclear magnetic resonance spectra of the oxidized [Fe(III)Rd] and reduced [Fe(II)Rd] forms of P. furiosus Rd exhibited substantial paramagnetic line broadening, and this precluded detailed 3D structural studies. The apoprotein was not readily amenable to NMR studies due to apparent protein oxidation involving the free cysteine sulfhydryls. However, high-quality NMR spectra were obtained for the Zn-substituted protein, Zn(Rd), enabling detailed NMR signal assignment for all backbone amide and alpha and most side-chain protons. Secondary structural elements were determined from qualitative analysis of 2D Overhauser effect spectra. Residues A1-K6, Y10-E14, and F48-E51 form a three-strand antiparallel beta-sheet, which comprises ca. 30% of the primary sequence. Residues C5-Y10 and C38-A43 form types I and II amide-sulfur tight turns common to iron-sulfur proteins. These structural elements are similar to those observed by X-ray crystallography for native Rd from the mesophile C. pasteurianum. However, the beta-sheet domain in P. furiosus Rd is larger than that in C. pasteurianum Rd and appears to begin at the N-terminal residue. From analysis of the secondary structure, potentially stabilizing electrostatic interactions involving the charged groups of residues Ala(1), Glu(14), and Glu(52) are proposed. These interactions, which are not present in rubredoxins from mesophilic organisms, may prevent the beta-sheet from "unzipping" at elevated temperatures.

BackgroundDelirium after cardiac surgery is associated with serious long-term negative outcomes and high costs. The aim of this study is to evaluate neurobehavioral, hemodynamic, and sedative characteristics of dexmedetomidine, compared with the current postoperative sedative protocol (remifentanil) in patients undergoing open heart surgery with cardiopulmonary bypass (CPB).MethodsOne hundred and forty two eligible patients who underwent cardiac surgery on CPB between April 2012 and March 2013 were randomly divided into two groups. Patients received either dexmedetomidine (range, 0.2 to 0.8 μg/kg/hr; n=67) or remifentanil (range, 1,000 to 2,500 μg/hr, n=75). The primary end point was the prevalence of delirium estimated daily via the confusion assessment method for intensive care.ResultsWhen the delirium incidence was compared with the dexmedetomidine group (6 of 67 patients, 8.96%) and the remifentanil group (17 of 75 patients, 22.67%) it was found to be significantly less in the dexmedetomidine group (p<0.05). There were no statistically significant differences between two groups in the extubation time, ICU stay, total hospital stay, and other postoperative complications including hemodynamic side effects.ConclusionThis preliminary study suggests that dexmedetomidine as a postoperative sedative agent is as sociated with significantly lower rates of delirium after cardiac surgery.

BackgroundPresenteeism, a concept that has recently undergone active study, is the act of attending work while sick. This study investigates the association between presenteeism and various psychosocial factors within workplaces.MethodsThis study analyzed 29246 wage earners from the third Korean Working Conditions Survey (KWCS, 2011) data using the logistic regression analysis to investigate the association between presenteeism and various psychosocial factors within workplaces.ResultsAmong the 29246 wage earners, 6347 (21.7 %) showed presenteeism. Those who experienced age discrimination at work (adjusted odds ratio (aOR) 1.77: 95 % CI 1.56–2.00), educational background discrimination (aOR 1.35: 95 % CI 1.22–1.51), regional discrimination (aOR 1.55: 95 % CI 1.31–1.83), sexual discrimination (aOR 1.65: 95 % CI 1.41–1.94), employment type discrimination (aOR 2.13: 95 % CI 1.89–2.40), physical violence (aOR 1.92: 95 % CI 1.45–2.55), sexual harassment (aOR 2.90: 95 % CI 2.01–4.19), job insecurity (aOR 1.36: 95 % CI 1.18–1.56), work–life imbalance (aOR 1.38: 95 % CI 1.29–1.47), low job satisfaction (aOR 2.04: 95 % CI 1.91–2.17), no colleague support (aOR 1.11: 95 % CI 1.02–1.21), job stress (aOR 1.89: 95 % CI 1.76–2.02), emotional labor (aOR 1.50: 95 % CI 1.41–1.60), high work intensity (aOR 1.31: 95 % CI 1.23–1.38), and 3 groups of job strain that are passive group (aOR 1.09: 95 % CI 1.00–1.18), active group (aOR 1.39: 95 % CI 1.28–1.51), and high strain group (aOR 1.35: 95 % CI 1.24–1.46) showed an increased risk of presenteeism compared to their respective counterparts (p < 0.01).ConclusionsThe study results confirmed the association between presenteeism and various psychosocial factors within workplaces. Considering that presenteeism negatively affects productivity and the mental and physical health of individuals, managing various psychosocial factors within workplaces is proposed to reduce presenteeism.

PurposeThe purpose of this study was to assess the association of organizational factors with work-related sleep problems (WRSP) among Korean workers.MethodsThe data were derived from the First Korean Working Conditions Survey conducted in 2006 with a representative sample of the Korean working population (n = 10,039).ResultsThe overall prevalence of WRSP was 5.1  % (95  % confidence interval (CI) 4.7–5.5). Those who experienced sexual harassment at work (adjusted odds ratio (aOR) 3.47: 95 % CI 1.77–6.81), discrimination due to sex (aOR 2.44: 95 % CI 1.36–4.36) or age (aOR 2.22: 95 % CI 1.52–3.23), violence at work (aOR 1.98: 95 % CI 1.06–3.68), threat of violence (aOR 1.96: 95 % CI 1.05–3.66), poor work-life balance (aOR 1.78: 95 % CI 1.44–2.20), low job satisfaction (aOR 1.69: 95 % CI 1.37–2.09), high cognitive (OR 1.64: 95 % CI 1.32–2.03) and emotional (aOR 1.53: 95 % CI 1.22–1.91) demands, job insecurity (aOR 1.32: 95 % CI 1.07–1.63), and high work intensity (aOR 1.55: 95 % CI: 95 % CI 1.25–1.92) had an increased risk of WRSP compared to their respective counterparts (p < 0.01). Low social support was not significantly associated with WRSP (aOR 0.88: 95 % CI 0.67–1.15).ConclusionThe results revealed that poor psychosocial working conditions may be related to a high prevalence of WRSP among representative Korean workers.