Investigation of the Structural Heterogeneity and Corrosion Performance of the Annealed Fe-Based Metallic Glasses.

This study investigated the structural heterogeneity, mechanical property, electrochemical behavior, and passive film characteristics of Fe-Cr-Mo-W-C-B-Y metallic glasses (MGs), which were modified through annealing at different temperatures. Results showed that annealing MGs below the glass transition temperature enhanced corrosion resistance in HCl solution owing to a highly protective passive film formed, originating from the decreased free volume and the shrinkage of the first coordination shell, which was found by pair distribution function analysis. In contrast, the enlarged first coordination shell and nanoscale crystal-like clusters were identified for MGs annealed in the supercooled liquid region, which led to a destabilized passive film and thereby deteriorated corrosion resistance. This finding reveals the crucial role of structural heterogeneity in tuning the corrosion performance of MGs.

Electrochemically dealloyed nanoporous Fe40Ni20Co20P15C5 metallic glass for efficient and stable electrocatalytic hydrogen and oxygen generation.

The anion exchange membrane (AEM) in fuel cells requires new, stable, and improved electrocatalysts for large scale commercial production of hydrogen fuel for efficient energy conversion. Fe40Ni20Co20P15C5, a novel metallic glass ribbon, was prepared by arc melting and melt spinning method. The metallic glass was evaluated as an efficient electrocatalyst in water-splitting reactions, namely hydrogen evolution reaction under acidic and alkaline conditions. In addition, oxygen evolution reaction in alkaline medium was also evaluated. In 0.5 M H2SO4, the metallic glass ribbons, after electrochemical dealloying, needed an overpotential of 128 mV for hydrogen evolution reaction, while in 1 M KOH they needed an overpotential of 236 mV for hydrogen evolution. For the oxygen evolution reaction, the overpotential was 278 mV. The electrochemical dealloying procedure significantly reduced the overpotential, and the overpotential remained constant over 20 hours of test conditions under acidic and alkaline conditions. The improved electrocatalytic activity was explained based on the metastable nature of metallic glass and the synergistic effect of metal hydroxo species and phosphates. Based on the excellent properties and free-standing nature of these metallic glass ribbons in electrolyte medium, we propose the current metallic glass for commercial, industrial electrocatalytic applications.

Deformations of Ti-6Al-4V additive-manufacturing-induced isotropic and anisotropic columnar structures: Insitu measurements and underlying mechanisms.

The deformations of isotropic and anisotropic Ti-6Al-4V columnar structures fabricated by additive manufacturing were extensively examined. The distinct texture and microstructure distributions were characterised. In situ X-ray diffraction measurements show different lattice activities resulting from the different microstructure distributions. Spatially resolved mapping revealed manufacturing-induced crystallite-orientation distributions that determine the deformation mechanisms. We propose a self-consistent model to correlate the multi-scale characteristics, from the anisotropic-texture-distribution microstructure to the bulk mechanical properties. We determined that basal and pyramidal slip activities were activated by tension deformation. The underlying additive-manufacturing-induced crystal plasticity plays a major role. We find that the texture development of the columnar structures and the distribution of crystallite orientation achieved by different processing conditions during additive manufacturing have important effects on the mechanical properties. The dominant deformation mode for the anisotropic Ti-6Al-4V columnar structure is basal slip, and that for the isotropic Ti-6Al-4V columnar structure is pyramidal slip. The difference may be important for determining the fatigue behaviour.

Improved kinetic behaviour of Mg(NH2)2-2LiH doped with nanostructured K-modified-LixTiyOz for hydrogen storage.

The system Mg(NH2)2 + 2LiH is considered as an interesting solid-state hydrogen storage material owing to its low thermodynamic stability of ca. 40 kJ/mol H2 and high gravimetric hydrogen capacity of 5.6 wt.%. However, high kinetic barriers lead to slow absorption/desorption rates even at relatively high temperatures (>180 °C). In this work, we investigate the effects of the addition of K-modified LixTiyOz on the absorption/desorption behaviour of the Mg(NH2)2 + 2LiH system. In comparison with the pristine Mg(NH2)2 + 2LiH, the system containing a tiny amount of nanostructured K-modified LixTiyOz shows enhanced absorption/desorption behaviour. The doped material presents a sensibly reduced (∼30 °C) desorption onset temperature, notably shorter hydrogen absorption/desorption times and reversible hydrogen capacity of about 3 wt.% H2 upon cycling. Studies on the absorption/desorption processes and micro/nanostructural characterizations of the Mg(NH2)2 + 2LiH + K-modified LixTiyOz system hint to the fact that the presence of in situ formed nanostructure K2TiO3 is the main responsible for the observed improved kinetic behaviour.

A Novel High-Pressure Tin Oxynitride Sn2 N2 O.

We report the first oxynitride of tin, Sn2 N2 O (SNO), exhibiting a Rh2 S3 -type crystal structure with space group Pbcn. All Sn atoms are in six-fold coordination, in contrast to Si in silicon oxynitride (Si2 N2 O) and Ge in the isostructural germanium oxynitride (Ge2 N2 O), which appear in four-fold coordination. SNO was synthesized at 20 GPa and 1200-1500 °C in a large volume press. The recovered samples were characterized by synchrotron powder X-ray diffraction and single-crystal electron diffraction in the TEM using the automated diffraction tomography (ADT) technique. The isothermal bulk modulus was determined as Bo =193(5) GPa by using in-situ synchrotron X-ray diffraction in a diamond anvil cell. The structure model is supported by DFT calculations. The enthalpy of formation, the bulk modulus, and the band structure have been calculated.

Mortality of severe septic patients between physician's high and low care volumes.

BACKGROUND: Patients with severe sepsis frequently require intensive care unit (ICU) admission and different ICU care models may influence their outcomes. The mortality of severe septic patients between physician's high and low care volume remains unclear. METHODS: We analyzed the data from a three-year prospective observation study, which was performed in an adult medical ICU of Chung Gung Memorial Hospital, Keelung. The data included initial bundle therapies based on the Surviving Sepsis Campaign (SSC) guidelines for patients with severe sepsis. RESULTS: Clinical data of total 484 patients with severe sepsis were recorded. Cox regression model showed that physician's care volume was an independent factor for lowering mortality in ICU patients with severe sepsis (hazard ratio 0.708; 95% confidence interval 0.514-0.974; p = 0.034). Patients treated by high care volume physician had four out of nine bundle therapies that were significantly higher in percentage following the SSC guidelines. These four therapies were renal replacement therapy, administration of low-dose steroids for septic shock, prophylaxis of gastro-intestinal bleeding, and control of hyperglycemia. CONCLUSION: High care volume physician may decrease mortality in ICU patients with severe sepsis through fitting bundle therapies for sepsis.

The role of endothelial microparticles in autoimmune disease patients with Raynaud's phenomenon.

BACKGROUND AND AIM: Raynaud's phenomenon (RP) is a microvascular disorder characterized by episodic peripheral vasospasm and ischemia and is commonly found in patients with autoimmune diseases (AID). The vasomotor homoeostasis and endothelial cells damage are involved in RP. Endothelial microparticles (EMPs) may act as a biomarker for endothelial damage. The aim of this study is to investigate the correlation between the levels of microparticles (MPs) and microvasculopathy in AID with RP. METHODS: Thirty-seven patients with AID and RP (RP group) and 27 patients with AID but without RP (non-RP group) were enrolled. The microvasculopathy score of RP was graded by nailfold capillary microscopy. The plasma levels of MPs were measured by flow cytometry utilizing specific labels for endothelial MPs (CD105 and CD144) and annexin V staining for phosphatidylserine bearing-MPs (annexin V+MPs). RESULTS: The levels of circulating EMPs (CD105+ p = 0.005, CD144+ p = 0.004), and the annexin V+ MPs (p < 0.001) were significantly elevated in the RP group compared with the non-RP group. Moreover, the high microvasculopathy scores were closely related with annexinV+ MPs levels in the RP group (p = 0.041). CONCLUSIONS: Levels of circulating EMPs and annexin V+ MPs are elevated in AID patients with RP indicate the endothelial damage and endothelial dysfunctions. In addition, levels of annexin V+ MPs can predict the severity of microvasculopathy in AID with RP.

Gold on Different Manganese Oxides: Ultra-Low-Temperature CO Oxidation over Colloidal Gold Supported on Bulk-MnO2 Nanomaterials.

Nanoscopic gold particles have gained very high interest because of their promising catalytic activity for various chemicals reactions. Among these reactions, low-temperature CO oxidation is the most extensively studied one due to its practical relevance in environmental applications and the fundamental problems associated with its very high activity at low temperatures. Gold nanoparticles supported on manganese oxide belong to the most active gold catalysts for CO oxidation. Among a variety of manganese oxides, Mn2O3 is considered to be the most favorable support for gold nanoparticles with respect to catalytic activity. Gold on MnO2 has been shown to be significantly less active than gold on Mn2O3 in previous work. In contrast to these previous studies, in a comprehensive study of gold nanoparticles on different manganese oxides, we developed a gold catalyst on MnO2 nanostructures with extremely high activity. Nanosized gold particles (2-3 nm) were supported on α-MnO2 nanowires and mesoporous ß-MnO2 nanowire arrays. The materials were extremely active at very low temperature (-80 °C) and also highly stable at 25 °C (70 h) under normal conditions for CO oxidation. The specific reaction rate of 2.8 molCO·h(-1)·gAu(-1) at a temperature as low as -85 °C is almost 30 times higher than that of the most active Au/Mn2O3 catalyst.

Outcomes of an emergency department intensive care unit in a tertiary medical center in Taiwan: An observational study.

PURPOSE: The boarding of critically ill patients in the emergency department (ED) could reduce quality of care and increase mortality. An ED intensive care unit (ICU) was set up in a 3715-bed medical center to facilitate timely delivery of critical care. This study reports comparative outcomes of EDICU patients with specialty ICU patients. MATERIALS AND METHODS: Medical records of adult nontrauma ED patients admitted to nonsurgical ICUs (EDICU, medical, cardiac, alimentary, and neurological units) between January 2007 and July 2011 were retrospectively reviewed. The respective number of admissions, bed turnover rate, and length of stay were compared. Cox regression models were also applied to compare inhospital mortality risks among these patients. RESULTS: With only 13% (14/108) of all ICU beds, EDICU admitted 36% (3711/10449) of patients. Emergency department ICU patients had an unfavorable adjusted hazard ratio for inhospital mortality compared with medical ICU and cardiac ICU patients, but after excluding patients with an ICU length of stay of 2 days or less, the difference in hazard ratio became nonsignificant. CONCLUSIONS: Emergency department ICU has admitted a disproportionately higher proportion of patients without sacrificing quality of care. Specialty care could be secured through direct communication between EDICU and specialty physicians and forming close collaboration between departments and ICUs.

Pulmonary embolism in a patient of tetralogy of Fallot: a diagnostic challenge.

A 46-year-old male patient with tetralogy of Fallot presented to the emergency department with progressive dyspnea for 3 days. The dyspnea was refractory to treatment for tet spells. Pulmonary embolism (PE) was subsequently diagnosed by computed tomography, and the patient was successfully treated with heparinization. Chronic hypoxemia-induced secondary polycythemia and the consequent increase in blood hyperviscosity predisposed this patient to PE. This case reminds us of the similarity in clinical presentation between PE and tet spells.

Elevated circulating levels of tissue factor-positive microvesicles are associated with distant metastasis in lung cancer.

PURPOSE: Microvesicles (MV) in the blood stream are associated with distant metastasis in cancer. Platelet or endothelial cell-related MV actively participate in thrombogenesis, which is an important step in cancer metastasis. This study investigated the correlations between MV levels of platelet-poor plasma and distant metastasis in lung cancer. METHODS: Platelet-poor plasma from 44 treatment-naive lung cancer (23 with distant metastasis) and 19 normal subjects was used to determine the levels of glycoprotein Iß (CD42) + platelet MV (PMV), P-selectin (CD62P) + PMV, VE-cadherin (CD144) + endothelial MV (EMV), tissue factor (CD142) + MV, thrombin-antithrombin complex and vascular endothelial growth factor (VEGF). RESULTS: The level of CD142 + MV was significant (odds ratio 5.86, 95 % confidence interval 1.31-38.3) in predicting distant metastasis in lung cancer, and a cutoff value of 2.668 (after logarithm transformation) in the ROC curve had a specificity of 90 % and a sensitivity of 59 %. The presence of distant metastasis showed a significant correlation between CD144 + EMV and VEGF, but not between CD144 + EMV and CD42 + PMV or CD62P + PMV in lung cancer subjects. CONCLUSIONS: The finding of CD142 + MV in platelet-poor plasma may be useful for suggesting distant metastasis in lung cancer. In addition to thrombogenesis, interaction between VE-cadherin and VEGF may be needed for successful metastasis in lung cancer.

Functional haplotypes in the promoter region of transcription factor Nrf2 in chronic obstructive pulmonary disease.

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) protects against oxidative stress which is important in the pathogenesis of chronic obstructive pulmonary disease (COPD). Three single nucleotide polymorphisms and 1 triplet repeat polymorphism are found in the promoter region of the Nrf2 gene. Molecular haplotyping of the Nrf2 promoter region was performed using DNA obtained from the peripheral blood of 69 COPD patients. The luciferase activities of Nrf2 promoter constructs containing all possible combinations of the 4 polymorphisms were determined and found to differ among the 16 haplotypes.The haplotypes isolated from the subjects were divided into 3 groups (L: low; M: medium; H: high) on the basis of luciferase activities. The proportions of subjects belonging to global initiative for chronic obstructive lung disease stage 3 or 4 decreased from the group with the LL haplotype to that with the HH haplotype. Presence of the LH or MM haplotype (hazard ratio, 3.36; 95% confidence interval, 1.16-9.69), gender (0.13; 0.02-0.67), and post-bronchodilator FEV1 value of predicted (0.95; 0.91-0.99) are significant predictors of respiratory failure development.The haplotype of the Nrf2 gene promoter affects its activity, and is associated with the severity and the development of respiratory failure in COPD.

Comparing hydrocortisone and methylprednisolone in patients with septic shock.

INTRODUCTION: Intravenous hydrocortisone of 200-300 mg/day for 7 days is suggested for patients with septic shock who require vasopressors to maintain mean artery pressure >or=65 mmHg, despite adequate fluid resuscitation. No study to date has compared the effects between physiologic doses of hydrocortisone and methylprednisolone in patients with septic shock. METHODS: From July 2007 to June 2008, patients who were admitted to the intensive care unit at Chang Gung Memorial Hospital, Keelung, Taiwan, with low-dose steroid therapy due to septic shock were enrolled in this study. The typical steroid therapy included 7 days of intravenous hydrocortisone 50 mg every 6 hours. Methylprednisolone (20 mg every 12 hours) was replaced in these patients from January 2008 because no hydrocortisone could be prescribed. RESULTS: A total of 21 patients were prescribed hydrocortisone and 19 patients were prescribed methylprednisolone. The survival rates for patients receiving hydrocortisone were relatively higher compared with those receiving methylprednisolone, but the difference was not significant. There were no significant differences in the Kaplan-Meier curves for the time to reverse shock between patients who received hydrocortisone, or methylprednisolone. Further regression analysis showed no significant independent factors associated with the survival rates and the time to reverse shock among age, sex, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, histories, and adverse events. CONCLUSIONS: Low-dose methylprednisolone and hydrocortisone might have a similar effect for the treatment of patients with septic shock.

Serial cytokine levels in patients with severe sepsis.

OBJECTIVE AND DESIGN: The serial or dynamic changes of cytokine levels in severely septic patients, between shock and no shock, survivors and non-survivors are still unclear. METHODS: Seventy-six patients with severe sepsis were enrolled to our study. Plasma levels of interferon-gamma, interleukin (IL)-6, IL-10, IL-12 and transforming growth factor-beta1 from day 1 to day 7 were determined. RESULTS: IL-6 level in non-survivors was higher than that in survivors on day 1. IL-10 level in non-survivors was higher than that in survivors on day 1, 2, and 3. IL-6 level in shock patients was higher than that in non-shock patients on day 1, 2, 6 and 7. IL-10 level in shock patients was higher than that in non-shock patients from day 1 to day 7. Plasma time-course curves of IL-6 and IL-10 were different between survivors and non-survivors. Plasma time-course curve of IL-6 was different between patients with shock and without shock. Regression analysis found that IL-6 was correlated with IL-10 and shock. IL-10 was correlated with IL-6 and mortality. CONCLUSION: IL-6 and IL-10 were the key cytokines in the pathogenesis of severe sepsis. IL-6 was comparatively more associated with septic shock and IL-10 was comparatively more associated with mortality.

The interleukin-4 expression in patients with severe sepsis.

PURPOSE: Sepsis is a complicated syndrome in which proinflammatory and anti-inflammatory cytokines are expressed simultaneously. However, it remains unclear for the expression of interleukin (IL)-4 and IL-4delta2 in patients with severe sepsis. MATERIALS AND METHODS: By nested reverse transcriptase-polymerase chain reaction and the expression of glyceraldehydes-3-phosphate dehydrogenase as the internal reference, the expression levels of IL-4 and IL-4delta2 were determined in peripheral blood mononuclear cells (PBMCs) of 76 patients with severe sepsis and were immediately admitted to an intensive care unit. Plasma IL-4 level was measured by enzyme-linked immunosorbent assay. Clinical characteristics were monitored and recorded prospectively. RESULTS: The IL-4 messenger RNA (mRNA) expression in PBMCs of patients who had survived was significantly higher than that of those who had died. The IL-4delta2/IL-4 ratio in PBMCs of patients who had survived was significantly lower than that of those who had died. The IL-4delta2 expression did not differ between survivors and nonsurvivors. After regression analysis, the IL-4delta2/IL-4 ratio still was an independent factor for death in patients with severe sepsis. The expression of IL-4delta2 mRNA was positively correlated with that of IL-4 mRNA in patients with severe sepsis. The plasma IL-4 levels in septic patients on admission day did not differ between survivors and nonsurvivors. CONCLUSIONS: The IL-4 mRNA expression might be associated with survival in patients with severe sepsis. The IL-4delta2/IL-4 ratio might be served as the net immunity of IL-4 activity.

Gene polymorphisms of fibrinolytic enzymes in coal workers' pneumoconiosis.

The authors assessed the gene polymorphisms of missense C/T polymorphism in exon 6 of the urokinase-plasminogen activator (PLAU) gene (PLAU P141L), Alu-repeat in intron 8 of the tissue-type plasminogen activator (PLAT) gene (PLAT TPA25 Alu insertion), and 4G/5G in the promoter region of the serine proteinase inhibitor, clade E (SERPINE) or plasminogen activator inhibitor type 1 gene (SERPINE1 -675 4G/5G) in 153 healthy volunteers and 154 retired coal miners with coal miners' pneumoconiosis (CWP). The CWP subjects included 94 individuals with simple pneumoconiosis and 60 individuals with progressive massive fibrosis presenting with worse pulmonary function. The distributions of genotypes of these three genes did not differ between the control and CWP subjects or between subjects with simple pneumoconiosis and those with progressive massive fibrosis. However, by assessing duration of work and its interaction with genotypes by means of logistic regression, the authors found the missense C/T polymorphism in exon 6 of the PLAU gene to be an effect modifier of the association between work duration and the development of progressive massive fibrosis.

Comparison optimal pressure between automatic titrating and predicting continuous positive airway pressure.

BACKGROUND: Optimal continuous positive airway pressure (CPAP) level reduced excessive daytime sleepiness and improved healthy status compared with subtherapeutic CPAP pressure for patients with obstructive sleep apnea syndromes. To date there have been no studies comparing the differences between the automatic CPAP titrating pressure levels (ACPAPL) and the predicting CPAP pressure levels (PCPAPL). In this study, we compared the differences between these two pressures and investigated the factors effecting ACPAPL and PCPAPL. METHODS: A retrospective study included 49 patients who were diagnosed with obstructive sleep apnea syndromes and prescribed CPAP therapy by physicians. ACPAPL as determined using automated CPAP was defined as 95th percentiles pressure. The PCPAPL was calculated according to body mass index (BMI), neck circumference (NC), and apnea/hypopnea index (AHI) formula. The paired t-test was used to compare ACPAPL and PCPAPL. The correlation analysis was used to determine the relationship between ACPAPL with maximum leak values, median leak values, 95th percentile leak value, BMI, NC, and AHI. RESULTS: The mean ACPAPL (10.4 +/- 1.8 cmH2O) was significantly higher than the mean PCPAPL (7.82 +/- 1.51 cmH2O). The differences in the results were statistically significant (p < 0.001). There were 98% of patients had air leaks. The ACPAPL had good correlation with maximum leaks (r = 0.44, 95% CI 0.18 to 0.64), median leak values (r = 0.46, 95% CI 0.20 to 0.66), and 95th percentile leak values (r = 0.30, 95% CI 0.02 to 0.54), however, the correlations with BMI (r = 0.05, 95% CI -0.23 to 0.33), NC (r = -0.18, 95% CI -0.44 to 0.10), and AHI (r = 0.23, 95% CI -0.06 to 0.48) were poor. CONCLUSION: The ACPAPL were higher than PCPAPL. The pressure differences between ACPAPL and PCPAPL were wide. Air leaks were common during the automatic CPAP titration. Leak value was one of the important factors that effected ACPAPL.

Incidental detection of an invasive thymoma during thallium-201 imaging for coronary artery disease.

Thallium-201 (Tl-201) is widely used for myocardial perfusion imaging, but is also reported to have potential tumor-seeking properties. Tl-201 uptake has been described in various malignant diseases, including thymic tumors. Thymomas are the most frequent tumors of the anterior mediastinum, and chest pain is one of the major presentation symptoms. Sometimes, a thymoma may be overlooked on chest plain film. We report on a case of a 63-year-old man who had a history of hypertension and suffered from intermittent chest pain for several weeks. He underwent a Tl-201 stress test to evaluate the presence of coronary artery disease, and during the test, abnormal uptake over focal extracardiac activity in the left upper mediastinum was incidentally revealed. Furthermore, chest computed tomography identified a 6-cm left anterior mediastinal mass. Mediastinal tumor resection was carried out, and the pathological examination demonstrated an invasive epithelial-type thymoma, which had invaded the left innominate vein. Subsequently, the patient received postoperative radiotherapy and thenceforth responded well to treatment. A Tl-201 scan has the potential to play a part in tumor detection and clinical assessment of therapeutic effects.