Genetic relationships between Candida albicans strains isolated from dental plaque, trachea, and bronchoalveolar lavage fluid from mechanically ventilated intensive care unit patients

Candida albicans often resides in the oral cavity of healthy humans as a harmless commensal organism. This opportunistic fungus can cause significant disease in critically ill patients, such as those undergoing mechanical ventilation in the intensive care unit (ICU) having compromised local airway defense mechanisms. The goal of this study was to determine the intra- and inter-patient genetic relationship between strains of C. albicans recovered from dental plaque, tracheal secretions, and the lower airway by bronchoalveolar lavage of patients undergoing mechanical ventilation. Three pulsed-field gel electrophoresis (PFGE) typing methods were used to determine the genetic relatedness of the C. albicans strains, including electrophoretic karyotyping (EK) and restriction endonuclease analysis of the genome using SfiI (REAG-S) and BssHII (REAG-B). The C. albicans isolates from dental plaque and tracheo-bronchial sites from the same patient were genetically indistinguishable and retained over time, whereas strains from different patients usually separated into different genotypes. Among the three methods, REAG-B proved to be the most discriminatory method to differentiate isolates. The finding of genetically similar strains from the oral and tracheo-bronchial sites from the same patient supports the notion that the oral cavity may serve as an important source for C. albicans spread to the trachea and lung of mechanically ventilated patients

Frequency and predictors of miliary tuberculosis in patients with miliary pulmonary nodules in South Korea: A retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Miliary pulmonary nodules are commonly caused by various infections and cancers. We sought to identify the relative frequencies of various aetiologies and the clinical and radiographic predictors of miliary tuberculosis (TB) in patients with miliary pulmonary nodules.</p> <p>Methods</p> <p>We performed a retrospective cohort study of patients who presented with micronodules occupying more than two-thirds of the lung volume, based on computed tomography (CT) of the chest, between November 2001 and April 2007, in a tertiary referral hospital in South Korea.</p> <p>Results</p> <p>We analyzed 76 patients with miliary pulmonary nodules. Their median age was 52 years and 38 (50%) were males; 18 patients (24%) had a previous or current malignancy and five (7%) had a history of TB. The most common diagnoses of miliary nodules were miliary TB (41 patients, 54%) and miliary metastasis of malignancies (20 patients, 26%). Multivariate analysis revealed that age ≤30 years, HIV infection, corticosteroid use, bronchogenic spread of lesions, and ground-glass opacities occupying >25% of total lung volume increased the probability of miliary TB. However, a history of malignancy decreased the probability of miliary TB.</p> <p>Conclusion</p> <p>Miliary TB accounted for approximately half of all causes of miliary pulmonary nodules. Young age, an immune-compromised state, and several clinical and radiographic characteristics increased the probability of miliary TB.</p

Au Nanoparticles as Interfacial Layer for CdS Quantum Dot-sensitized Solar Cells

Quantum dot-sensitized solar cells based on fluorine-doped tin oxide (FTO)/Au/TiO2/CdS photoanode and polysulfide electrolyte are fabricated. Au nanoparticles (NPs) as interfacial layer between FTO and TiO2 layer are dip-coated on FTO surface. The structure, morphology and impedance of the photoanodes and the photovoltaic performance of the cells are investigated. A power conversion efficiency of 1.62% has been obtained for FTO/Au/TiO2/CdS cell, which is about 88% higher than that for FTO/TiO2/CdS cell (0.86%). The easier transport of excited electron and the suppression of charge recombination in the photoanode due to the introduction of Au NP layer should be responsible for the performance enhancement of the cell

Inhibition of Dengue Virus Entry and Multiplication into Monocytes Using RNA Interference

Prevention and treatment of dengue infection remain a serious global public health priority. Extensive efforts are required toward the development of vaccines and discovery of potential therapeutic compounds against the dengue viruses. Dengue virus entry is a critical step for virus reproduction and establishes the infection. Hence, the blockade of dengue virus entry into the host cell is an interesting antiviral strategy as it represents a barrier to suppress the onset of infection. This study was achieved by using RNA interference to silence the cellular receptor, and the clathrin mediated endocytosis that enhances the entry of dengue virus in monocytes. Results showed a marked reduction of infected monocytes by flow cytometry. In addition, both intracellular and extracellular viral RNA load was shown to be reduced in treated monocytes when compared to untreated monocytes. Based on these findings, this study concludes that this therapeutic strategy of blocking the virus replication at the first stage of multiplication might serve as a hopeful drug to mitigate the dengue symptoms, and reduction the disease severity

RNA Interference Mediated Inhibition of Dengue Virus Multiplication and Entry in HepG2 Cells

Background: Dengue virus-host cell interaction initiates when the virus binds to the attachment receptors followed by endocytic internalization of the virus particle. Successful entry into the cell is necessary for infection initiation. Currently, there is no protective vaccine or antiviral treatment for dengue infection. Targeting the viral entry pathway has become an attractive therapeutic strategy to block infection. This study aimed to investigate the effect of silencing the GRP78 and clathrin-mediated endocytosis on dengue virus entry and multiplication into HepG2 cells. Methodology/Principal Findings: HepG2 cells were transfected using specific siRNAs to silence the cellular surface receptor (GRP78) and clathrin-mediated endocytosis pathway. Gene expression analysis showed a marked down-regulation of the targeted genes (87.2%, 90.3%, and 87.8 % for GRP78, CLTC, and DNM2 respectively) in transfected HepG2 cells when measured by RT-qPCR. Intracellular and extracellular viral RNA loads were quantified by RT-qPCR to investigate the effect of silencing the attachment receptor and clathrin-mediated endocytosis on dengue virus entry. Silenced cells showed a significant reduction of intracellular (92.4%) and extracellular viral RNA load (71.4%) compared to non-silenced cells. Flow cytometry analysis showed a marked reduction of infected cells (89.7%) in silenced HepG2 cells compared to non-silenced cells. Furthermore, the ability to generate infectious virions using the plaque assay was reduced 1.07 log in silenced HepG2 cells

Perceived managerial and leadership effectiveness in a Korean context: An indigenous qualitative study

Multinational corporations (MNCs) across the world have sent an increasing number of managers abroad to leverage unprecedented opportunities in the era of globalization. However, their failure rate has been above 33% for decades, resulting in substantial costs (Puck, Kittler, & Wright, 2008). One of the primary reasons for this failure is a lack of understanding of the national and organizational cultures within the host countries (Festing & Maletzky, 2011). For example, while a number of MNCs have entered the Korean market, several such as Yahoo, Motorola, and Walmart have failed and withdrawn due to the companies’ lack of adjustment to the Korean cultural context (Choe, 2006; Woo, 2013). In spite of the significance of culturally embedded practices, most researchers who have explored management and leadership in Asian countries, whether they were Western or indigenous researchers, have implemented studies using extant Western management and leadership theories derived within the Western cultural context (Leung, 2007; Tsui, 2006). Numerous scholars have claimed that this could be problematic because the findings of such studies may not be applicable to non-Western countries (Li, 2012; Liden & Antonakis, 2009), and may fail to provide insights and understanding of novel contexts or to reveal indigenous aspects of management and leadership (Tsui, 2007). Consequently, there have been increasing calls for indigenous management and leadership research within Asian countries (see Li et al., 2014; Lyles, 2009; Tsui, 2004; Wolfgramm, Spiller, & Voyageur, 2014). Over the past 30 years, managerial effectiveness and leadership effectiveness have been substantially neglected areas of management research (Noordegraaf & Stewart, 2000; Yukl, Gordon, & Taber, 2002). In addition, there has been little agreement on what specific behaviors distinguish effective managers from ineffective ones. Furthermore, more research is needed to examine the managerial and leadership behaviors that are critical for shaping the performance of individuals, groups and organizations (see Borman & Brush, 1993; Cammock, Nilakant & Dakin, 1995; Mumford, 2011; Noordegraaf & Stewart, 2000; Yukl et al., 2002). While most of the research related to managerial and leadership effectiveness has been conducted in the U.S., the few notable non-U.S. studies include that of Cammock et al. (1995) in New Zealand who developed a behavioral lay model of managerial effectiveness using the repertory grid technique. Another notable exception is the cumulative series of perceived managerial and leadership effectiveness studies conducted by Hamlin with various indigenous co-researchers in Western and non-Western countries (see Hamlin & Patel, 2012; Ruiz, Wang, & Hamlin, 2013) using Flanagan’s (1954) critical incident technique (CIT)

SYNTHESES AND CHARACTERIZATION OF THE RUTHENIUM CARBONYL PORPHYRIN COMPLEXES RU(TPP)(CO)(1-MEIM) AND RU(ALPHA-POCPIVP)(CO)(1-MEIM)

Ru(TPP)(CO)(1-MeIm) and Ru(alpha-PocPivP)(CO)(1-MeIm) (TPP = tetraphenylporphyrinato; PocPivP = &apos;pocket&apos; porphyrin dianion) were prepared by metalation of the free-base porphyrins with Ru-3(CO)(12), followed by reaction with 1-MeIm. The structures of Ru(TPP)(CO)(1-MeIm) and Ru(alpha-PocPivP)(CO)(1-MeIm) have been determined by single-crystal X-ray diffraction methods. The compound Ru(TPP)(CO)(1-MeIm) packs as one crystallographically independent porphyrin molecule with toluene solvate, whereas Ru(alpha-PocPivP)(CO)(1-MeIm) crystallizes as two crystallographically independent porphyrin molecules, molecule A and molecule B, with disordered solvate, modeled as water. In Ru(TPP)(CO)(1-MeIm) the Ru atom lies 0.032 Angstrom out of the 24-atom porphyrin plane toward the CO ligand. The Ru-C-O bond angle is 179.3(2)degrees and the Ru-C(CO) and C-O bond distances are 1.828(2) Angstrom and 1.147(3) Angstrom, respectively. The Ru-N-ax(1-MeIm) distance is 2.187(2) Angstrom, compared with an average Ru-N-eq(porphine) distance of 2.058(3) Angstrom. The molecular structure of Ru(alpha-PocPivP)(CO)(1-MeIm), a sterically protected &apos;pocket&apos; porphyrin, is more distorted than that of Ru(TPP)(CO)(1-MeIm). In molecule A the Ru atom lies 0.03 Angstrom out of the 24-atom porphyrin plane toward the 1-MeIm ligand whereas in molecule B the Ru atom lies 0.01 Angstrom out of the porphyrin plane toward the CO ligand. For molecule A the Ru-C(CO) and C-O bond distances are 1.82(3) Angstrom and 1.18(3) Angstrom, respectively, and the Ru-C-O bond angle is 168(3)degrees. Respective values for molecule B are 1.82(2) Angstrom, 1.16(3) Angstrom, and 159(3)degrees. The M-N-ax distances are 2.20(2) Angstrom and 2.16(2) Angstrom, respectively, for molecules A and B. The average M-N-eq distances are 2.03(3) Angstrom and 2.03(5) Angstrom. The CO stretching frequencies are 1939 cm(-1) for Ru(TPP)(CO)(1-MeIm) and 1933 cm(-1) for Ru(alpha-PocPivP)(CO)(1-MeIm). Crystallographic data for Ru(TPP)(CO)(1-MeIm): triclinic, C-i(1)-P (1) over bar, Z = 2, a = 9.796(2) Angstrom, b = 13.320(1) Angstrom, c = 17.618(2) Angstrom, alpha = 74.88(1)degrees, beta = 87.97(1)degrees, gamma = 83.23(1)degrees, T = 153 K, 9049 unique reflections, 579 variables, R(F) (F-o(2) > 2 sigma(F-o(2))) = 0.034, R(w)(F-2) = 0.094. Crystallographic data for Ru(alpha-PocPivP)(CO)(1-MeIm): orthorhombic, C-2v(9)-Pn2(1)a, Z = 8, a = 26.672(5) Angstrom, b = 32.243(6) Angstrom, c = 14.124(3) Angstrom, T = 150 K, 8006 unique reflections, 699 variables, R(F) (F-o(2) > 2 sigma(F-o(2))) = 0.113, R(w)(F-2) = 0.246.X1112sciescopu