The microchip laser performance of Yb:YAG crystals doped with different ytterbium concentrations (CYb=10, 15, and 20 at.%) has been investigated at ambient temperature without active cooling of the ...gain media. Efficient laser oscillation for a 1-mm-thick YAG doped with 10 at.% Yb3+ ions was achieved at 1030 and 1049 nm with slope efficiencies of 85% and 81%, correspondingly. The laser performance of heavy-doped Yb:YAG crystals was limited by the thermal population at terminated lasing level and thermal lens effect at room temperature without sufficient cooling of the samples. The laser emitting spectra of Yb:YAG microchip lasers with different Yb concentrations and output couplings are addressed with the local temperature rise, due to the absorption of the pump power inside the gain media under different pump levels.
Summary Background The aim of this study was to identify risk factors for development of severe sepsis or septic shock and to evaluate the clinical impact of severe sepsis on outcome in patients with ...gram-negative bacteremia (GNB). Methods From the database of a nationwide surveillance for bacteremia, patients with GNB were analyzed. Data of patients with severe sepsis or septic shock were compared with those of patient with sepsis. Results Of 2286 patients with GNB, 506 (22.1%) fulfilled the criteria of severe sepsis or septic shock. Factors associated with severe sepsis or septic shock in the multivariate analysis included renal disease, indwelling urinary catheter, hematologic malignancy, and neutropenia. The 30-day mortality of patients with severe sepsis or septic shock was significantly higher than that of patients with sepsis (39.5% 172/435 vs. 7.4% 86/1170; P < 0.001). Multivariable analysis revealed that solid tumor, liver disease, pulmonary disease, pneumonia, and pathogens other than Escherichia coli , which were risk factors of development of severe sepsis or septic shock, were also found to be strong predictors of mortality. Severe sepsis or septic shock was a significant factor associated with mortality (OR, 3.34; 95% CI, 2.35–4.74), after adjustment for other variables predicting poor prognosis. Conclusions Severe sepsis or septic shock was a common finding in patients with GNB, predicting a higher mortality rate. Renal disease and indwelling urinary catheter were the most important risk factors significantly associated with severe sepsis or septic shock among patients with GNB.
The exposure of pregnant females to stress during a critical period of fetal brain development is an environmental risk factor for the development of schizophrenia in adult offspring. Schizophrenia ...is a group of common mental disorders of unclear origin, affecting approximately 1% of the global population, showing a generally young age at onset. In the present study, a repeated variable stress paradigm was applied to pregnant rats during the final week of gestation. The effects of an extract of Panax ginseng C.A. Meyer (PG) on rats exposed to prenatal stress (PNS) were investigated in terms of behavioral activity and protein expression analyses. In the behavioral tests, grooming behavior in a social interaction test, line-crossing behavior in an open-field test and swimming activity in a forced-swim test were decreased in the rats exposed to PNS compared with the non-stressed offspring; the changes in behavioral activity were reversed upon oral treatment with PG (300 mg/kg). Subsequently, western blot analysis and immunohistochemical analyses of the prefrontal cortex and hippocampus revealed that the downregulation of several neurodevelopmental genes which occurred following exposure to PNS was reversed upon treatment with PG. The current findings demonstrate that the downregulation of several genes following exposure to PNS may affect subsequent behavioral changes, and that these phenomena are reversed following treatment with PG during pregnancy. Our results suggest that oral treatment with PG reduces the incidence of psychiatric disorders, such as schizophrenia.
Purpose Elderly smokers have a reduced chest diameter due to weakening of the respiratory muscles, and this results in decreased ventilation, leading to a vicious circle. Therefore, the present study ...investigated the effects of an intervention program to enhance the pulmonary function and muscle activity of elderly smokers. Subjects and Methods Participants were randomly assigned to one of two experimental groups or a control (CG) group. The experimental groups performed exercises three times per week for six weeks, whereas the CG performed no exercises. One of the experimental groups performed a Feedback Breathing Exercise (FBE) for 15 minutes, and the other repeated three sets of Balloon-Blowing Exercises (BBE) with sufficient rest of more than one minute between sets. Results In the experimental groups, FVC, FEV1/FVC, PEF and muscle activity of the rectus abdominis significantly improved after four weeks, but no significant differences were observed in FEV1 or VC after six weeks. Conclusion The results show that FBE and BBE improved the pulmonary functions of elderly smokers, demonstrating the potential benefits of the development of various training methods using balloons, and group programs, including recreational factors, for increasing respiratory muscles strength.
The CUPID code has been developed at KAERI for a transient, three-dimensional analysis of a two-phase flow in light water nuclear reactor components. It can provide both a component-scale and a ...CFD-scale simulation by using a porous media or an open media model for a two-phase flow. In this paper, recent advances in the CUPID code are presented in three sections. First, the domain decomposition parallel method implemented in the CUPID code is described with the parallel efficiency test for multiple processors. Then, the coupling of CUPID-MARS via heat structure is introduced, where CUPID has been coupled with a system-scale thermal-hydraulics code, MARS, through the heat structure. The coupled code has been applied to a multi-scale thermal-hydraulic analysis of a pool mixing test. Finally, CUPID-SG is developed for analyzing two-phase flows in PWR steam generators. Physical models and validation results of CUPID-SG are discussed.
A theoretical model based on a quasi-four-level system is modified to investigate the effect of Yb concentration on performance of continuous-wave Yb:YAG microchip lasers by taking into account ...temperature-dependent thermal population distribution, temperature-dependent emission cross-section and concentration-dependent fluorescence lifetime, thermal loading, thermal conductivity, and thermal expansion coefficient. The local temperature rise in Yb:YAG crystal caused by the absorbed pump power plays an important role in the laser performance of Yb:YAG microchip lasers working at ambient temperature without actively cooling the sample. The output wavelengths dependent on output coupling, Yb concentration, and pump power level were analyzed quantitatively. The numerical simulation of Yb:YAG microchip lasers is in good agreement with experimental data. The optimized laser operation for Yb:YAG microchip lasers is proposed by varying the thickness and output coupling for different Yb concentrations. The effect of thermal lens, thermal deformation effect, and saturated inversion population distribution inside the Yb:YAG crystal on performance of heavy-doped Yb:YAG microchip lasers are also addressed.
Asiatic acid, a triterpenoid derived from Centella asiatica, is a putative anticancer agent in several types of cancer cells. Investigations of its biological role in negative regulation of cell ...growth have focused on the extent of induction of apoptosis in a cell-type-specific manner. In this study, we identified an important regulator of asiatic acid-induced cell death, microRNA (miR)-1290, which sensitizes cells to asiatic acid-induced cytotoxicity and negatively regulates BCL2 expression. Asiatic acid significantly upregulated miR-1290, and asiatic acid-induced cell death was shown to be dependent on miR-1290 activity. Molecular assays demonstrated that BCL2 mRNA is a direct target of miR-1290-mediated RNA interference. The results of functional studies suggest that miR-1290 suppresses cell viability and cell cycle progression. These data provide insight into miR-1290-mediated cellular mechanisms in asiatic acid-treated A549 non-small cell lung carcinoma cells.
There are multiple lines of evidence that a variety of natural fatty acids are effective in health promotion. Among these fatty acids, conjugated linoleic acid (CLA)-a collective term referring to a ...mixture of positional and geometric isomers of linoleic acid (LA, cis-9, cis-12-octadecadienoic acid)-is currently under intensive investigation due to its health-promotion potential. The antitumor activity of CLA is of special interest, since it shows inhibitory effects against multistage carcinogenesis at relatively low dietary levels. Many studies using in vivo and in vitro models have shown that CLA suppresses the development of multistage carcinogenesis at different sites. The research to date on CLA has provided a vast amount of information about the mechanism on how CLA functions in the prevention of cancer. This article discusses characteristics of CLA in the prevention of cancer in both in vivo and in vitro studies and the possible underlying chemoprevention mechanisms.
To date, there has been much controversy about the role of crescentic lesion as a significant prognostic factor in immunoglobulin A nephropathy (IgAN). This study evaluated whether crescentic lesions ...predict adverse renal outcomes in IgAN patients.
A total of 430 patients with biopsy-proven IgAN between January 2000 and December 2009 were included. Histological variables of the Oxford classification (Oxford-MEST) and the presence of crescents were assessed. The primary endpoint was a 50% decline in estimated glomerular filtration rate.
Of the 430 patients, 81 (18.8%) had a crescentic lesion. During a mean follow-up of 61 months, the primary outcome occurred in 19 (23.5%) patients with crescents compared with 40 (11.5%) patients without crescents (P=0.01). A Kaplan-Meier plot showed that the 10-year renal survival rate was significantly lower in patients with crescents than patients without crescents (P=0.01). However, in a multivariable Cox analysis which included clinical factors and the Oxford-MEST, crescents were not significantly associated with an increased risk of developing the primary outcome hazard ratio: 0.71, 95% confidence interval (CI) 0.36-1.41, P=0.33. Furthermore, adding crescents to the Oxford-MEST did not improve the discriminative ability for the prediction of renal outcomes c-statistic: 0.86 (0.81-0.91) vs. 0.86 (0.80-0.91), P=0.21.
Crescentic lesion was not an independent prognostic factor, suggesting that crescents have limited value in predicting renal outcomes of IgAN.
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