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This study investigates the effect of implementing a field plate on a GaN high-electron-mobility transistor (HEMT) to improve power device reliability. The results indicate that the field plate structure reduces the peak electrical field and interface traps in the device, resulting in higher breakdown voltage, lower leakage current, smaller current collapse, and better threshold voltage control. Furthermore, after high voltage stress, steady dynamic on-resistance and gate capacitance degradation improvement were observed for the device with the field plate. This demonstrates that GaN device reliability can be improved by using the field plate approach.

In this letter, we present high-performance AlGaN/GaN high electron mobility transistor (HEMT) by 3-dimensional (3D) tri-gate. Due to the excellent channel control of tri-gate structure, the tri-gate HEMT shows the low subthreshold swing (SS) of 65 mV/decade, low off-state drain leakage current (Ioff) of 7 nA/mm, and On/Off ratio up to 7.6 × 107. Furthermore, we combined the tri-gate structure and metal oxide semiconductor (MOS) structure. The tri-gate MOS-HEMT with high-k dielectric oxide HfO2 was fabricated. The good interface between HfO2 and AlGaN and strain-induce polarization increase the carrier concentration. Compared to the tri-gate HEMT, the increased maximum drain current, higher On/Off ratio and better breakdown voltage is demonstrated by implanted the high k dielectric HfO2. The improved electrical performance of tri-gate MOS-HEMT shows potential for next generation power application.

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Background Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of vitamin D deficiency. Vitamin D levels also correlate with lung function in patients with COPD. However, there are few reports on vitamin D deficiency and emphysema severity in COPD. This study aimed to investigate the effects of plasma 25-hydroxyvitamin D (25-OHD) level on emphysema severity in male COPD patients. Methods A total of 151 male subjects were selected from the Korean Obstructive Lung Disease (KOLD) cohort. Subjects were subdivided into four subgroups according to their baseline plasma 25-OHD level: sufficiency (≥20 ng/ml), mild deficiency (15–20 ng/ml), moderate deficiency (10–15 ng/ml), and severe deficiency ( Results Baseline computed tomography (CT) emphysema indices revealed significant differences among the subgroups (p = 0.034). A statistically significant difference was also observed among the subgroups regarding change in the CT emphysema index over 3 years (p = 0.047). The annual increase in emphysema index was more prominent in the severe deficiency group (1.34% per year) than in the other groups (0.41% per year) (p = 0.003). Conclusions This study demonstrates that CT emphysema indices were different among the four subgroups and supports that severe vitamin D deficiency is associated with rapid progression of emphysema in male patients with COPD.

Background: The gut microbiota has been known to affect lung immunity and inflammation. Interactions between the gut microbiota and lung, called the gut-lung axis, might influence lung function. However, it is unclear whether dysbiosis of the gut microbiota correlates with lung function. The objective of this study was to demonstrate whether there is an association between the gut microbiota and lung function in Korean population. Methods: This research was performed using spirometry data and sequencing data of the 16S rRNA gene in 1,307 adults. We tested differences in the overall microbial composition and taxa abundance according to forced expiratory volume in one second (FEV1) % predicted. Statistical analyses were performed while controlling for potential confounders such as smoking history and correcting for multiple testing. Findings: As FEV1 % predicted decreased, the phylogenetic diversity index of the gut microbiota, one of the alpha diversity indices, was reduced. The abundance Fusobacteriaceae increased as FEV1 % predicted decreased (q-value

Platelet count reflects the severity and prognosis of multiple diseases. Additionally, alterations in gut microbiota have been linked to several chronic diseases. The purpose of this study was to investigate the association between gut microbiota and platelet count. We selected 1268 subjects with fecal 16S RNA gene sequencing data from a Healthcare Screening Center cohort. Based on the third quartile of platelets (277 &times, 109/L), we compared the gut microbiota between the upper quartile (n = 321) and lower three quartiles groups (n = 947). The upper quartile group had lower alpha diversity based on observed amplicon sequence variants (q = 0.004) and phylogenetic index (q &lt, 0.001) than the lower three quartiles group. Significant differences were also found in the weighted UniFrac distance (q = 0.001) and Jaccard dissimilarity (q = 0.047) beta diversity measures between the two groups. Compared with the lower three quartiles group, the upper quartile group exhibited decreased relative abundances of the genus Faecalibacterium, which was also inversely correlated with the platelet count. Increased platelet count was associated with reduced diversity in gut microbiota and lower abundances of Faecalibacterium with beneficial gut bacteria spices F. prausnitzii, suggesting that an increased platelet count, even within normal range, may adversely affect gut microbial diversity and composition.

Background The 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been recommended for adults aged ≥65 years. To evaluate functional immune response against the additional 11 serotypes that are included in PPSV23, but not the 13-valent pneumococcal conjugate vaccine (PCV13), serotype-specific anti-pneumococcal antibodies were examined using an opsonophagocytic assay (OPA). Methods Participants ≥65 years of age that were naive to the pneumococcal vaccine were enrolled. They were divided into two groups according to their age: group 1 (N = 30; aged 65–74 years) and group 2 (N = 32; aged ≥75 years). The functional antibody response prior to and 4 weeks post-immunization with PPSV23 was determined, using a multiplexed OPA (MOPA) for 11 pneumococcal serotypes (2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20B, 22F, and 33F). Results Geometric mean OPA titers (GMTs) to 11 serotypes were significantly increased in both groups post-immunization compared to those prior to immunization. The GMTs for all serotypes were not significantly different between the two groups after immunization. The proportion of subjects with OPA titers post-immunization of ≥8 and ≥64 was 93–100% and 80–100% for the 11 serotypes, respectively, while subjects with a ≥4-fold increase in OPA titers ranged from 9 to 90% for the 11 serotypes. Conclusions This study revealed that PPSV23 vaccination induced significant functional immune responses to 11 non-PCV13 serotypes in older adults. The MOPA has been shown to be a useful tool for future application in evaluating new PCVs in older adults. The clinical trial registration number is KCT 0001963 (CRIS, https://cris.nih.go.kr/cris/en/ ).

We present the case of 51-year-old woman with a primary breast leiomyosarcoma. On the postoperative screening after breast cancer surgery, a 4-mm-sized mass assessed as BI-RADS category 3 was detected on her contralateral breast. We recommended follow-up and observation. However, the lesion increased in size and became palpable. It was excised and diagnosed as primary leiomyosarcoma. We review the literature on imaging findings and management of breast leiomyosarcoma, and discuss the differential diagnoses in breast imaging.

The insufficient long-term durability of polymer electrolyte membrane fuel cell (PEMFC) stacks has been blocking commercialization of PEMFC technologies. An accelerated degradation test (ADT) is needed to facilitate the PEMFC development process by reducing the testing time. We propose an ADT procedure for a PEMFC stack with the concept of series reliability structure under startup–shutdown cycling testing conditions. The acceleration factor is estimated to fit the degradation paths of individual cells consisting of the PEMFC stack under normal use conditions via the accelerated degradation data of a single cell. We employ a nonparametric regression method to smooth the degradation curves observed from accelerated operating conditions. We illustrate the methodology for estimating the lifetime of the PEMFC stack using the theory of the smallest-order statistics. We propose a three-parameter Weibull distribution in fuel cell technology to fit the failure data of cells in a PEMFC stack.

Purpose This study described the acute hypoxemic respiratory failure (AHRF) population and identified potential modifiable markers of outcome. Methods A prospective, multicenter study was performed in 22 intensive care units (ICUs). The clinical outcomes of patients with acute respiratory distress syndrome (ARDS) were compared to the outcomes in patients with non-ARDS AHRF, and a propensity score matched analysis was performed. Results A total 837 patients with an arterial oxygen tension/fraction of inspired oxygen ratio (Pa o 2/F io 2) less than 300 mm Hg on ICU admission were included. Of these, 163 patients met the criteria defining ARDS, whereas the remaining 674 patients who had unilateral or no pulmonary opacities were classified as non-ARDS AHRF. Baseline Pa o 2/F io 2 ratio, thrombocytopenia, increased positive end-expiratory pressure (PEEP) were significantly associated with the 60-day mortality in hypoxemic respiratory failure after multivariate analysis. However, ARDS was not associated with increased 60-day mortality when independent predictors for the 60-day mortality and propensity score were controlled. In the case-control study, the 60-day mortality rate was 38.6% in the ARDS group and 32.3% in the non-ARDS AHRF group. In both patients with ARDS and non-ARDS AHRF, the mortality rate increased proportionally to a lower baseline Pa o 2/F io 2. Conclusion Lower baseline oxygenation (Pa o 2/F io 2) is a poor prognostic marker in acute hypoxemic respiratory failure.

This study evaluates the association between the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) and hospital mortality in general critically ill patients.This is a retrospective cohort study that analyzes prospective collected data from the Validation of Simplified acute physiology score 3 in Korean Intensive care unit study. The study population comprised patients who were consecutively admitted to participating intensive care units from July 1, 2010, to January 31, 2011. Univariate and multivariate logistic regression models were used to evaluate the effect of ECOG-PS on hospital mortality.A total of 3868 patients were included in the analysis. There was a significant trend for increasing hospital mortality as the ECOG-PS grade became higher (P.001). There was a trend of increasing adjusted odds ratio for hospital mortality, with grade 1 of PS 1.4 (95% confidence intervals [CIs], 1.0-1.8), grade 2 of PS 2.0 (95% CIs, 1.5-2.7), grade 3 of PS 2.9 (95% CIs, 2.1-4.1), and grade 4 of PS 2.5 (95% CIs, 1.6-3.9). Also, there was a significant difference in all grades. Subgroup analysis showed a trend of increasing hospital mortality regardless of the presence of cancer.Preadmission PS, assessed with ECOG-PS in critically ill patients, has prognostic value in general critically ill patients.

During continuous power operation for 2740 h, the major mechanisms and patterns of performance degradation in a polymer electrolyte membrane fuel cell (PEMFC) stack are investigated under low cathode humidification with simulated reformate fuel gases through the use of various physicochemical and electrochemical analysis tools. As operating time increases, the operating voltages and open-circuit voltages (OCVs) of the stack decrease with the large voltage distributions. In the post-mortem analysis of the stack, the delamination of the catalyst layer (CL) of unstable operating membrane electrode assemblies (MEAs) is significant near the cathode gas inlets. This observation is in agreement with the results of OCV, hydrogen crossover current, and anode off-gas measurements. This phenomenon may be due to the acceleration of carbon corrosion in the cathode during the frequent start-up and shut-down process, because the local cathode potential can reach more than 1.5 V in the air/fuel boundary. Additionally, the frequent membrane hydration and dehydration by the accumulation of excess water (through electrochemical reaction) and faster water evaporation (under dry-air cathode conditions and high operating temperatures) may accelerate the interface delamination between the membrane and cathode CL with a substantially uneven distribution of water.

Objective To compare the performance of combined screening with digital mammography and ultrasound, using modified criteria for breast ultrasound screening, versus conventional screening with digital mammography alone in Korea. Methods From May 2016 to March 2018, 5,969 asymptomatic women aged 40–59 years old were enrolled in a prospective cohort study from 12 university-affiliated hospitals participating in the MUST-BE (Mammography and Ultrasonography STudy for Breast cancer screening Effectiveness) trial. Full-field digital mammography and radiologist-performed hand-held breast ultrasound were obtained in all cases. For this study, new criteria for breast ultrasound screening were established via modification of the BI-RADS (Breast Imaging Reporting and Data System) criteria. In the combined screening, the same radiologist interpreted both mammography and ultrasound; in the conventional screening, a second radiologist in another hospital interpreted the mammography on a monthly basis without any ultrasound findings or follow-up results. We identified positive cases, including those probably benign or inconclusive and those suspicious, and compared the recall rate, positive predictive value (PPV), and cancer detection rate (CDR) per 1,000 women screened by one of the two screening methods. The reference standard was obtained from histological results and a 12-month breast ultrasound follow-up period. Results There were 421 probably benign and 287 suspicious cases in the combined screening, and 618 inconclusive and 48 suspicious cases in the conventional screening. We performed biopsy in 231 and 89 women and detected 45 and 31 cancer patients in the combined and conventional screenings, respectively. The recall rate was 11.9% and 11.2%, respectively (p=0.03). The preliminary PPV1 was 6.4% and 4.7%, respectively (p=0.17) and the CDR was 7.5 and 5.2 per 1,000 women screened, respectively (p=0.11). Conclusions Using the MUST-BE criteria, the combined screening with digital mammography and ultrasound might result in similar PPV1 and CDR compared to conventional screening with digital mammography alone but a higher recall rate.

Purpose To assess the value of screening ultrasonography (US) in the detection of nonpalpable locoregional recurrence following mastectomy for breast cancer and to describe the US appearances of occult recurrent cancers. Materials and methods During a 36-month period, 1180 consecutive US screenings were performed for mastectomy sites and ipsilateral axillary fossae in 468 asymptomatic women who had undergone mastectomy for breast cancer. All US results were divided into three groups: negative findings, probably benign nodules, and suspicious for malignant nodules. The final diagnoses were based on pathology results and clinical or sonographic follow-up for more than 12 months. The diagnostic performance of US for detecting nonpalpable locoregional recurrence was assessed. The US appearances of occult recurrent cancers were retrospectively reviewed. Results Of the 468 patients assessed, 19 (4.1%) showed “suspicious for malignant nodules”; of these lesions, 10 were malignant. One false-negative case was identified. The sensitivity and specificity were 90.9% and 98.0%, respectively. A biopsy positive predictive value of 52.6% was observed. Cancer detection rates were 2.1% with US screenings of mastectomy sites and ipsilateral axillary fossae. The common US features of occult recurrences at the mastectomy sites were irregular shaped, not-circumscribed marginated, and hypoechoic masses with intratumoral vascularities. The most common location was within the deep muscle layer. Conclusion Although locoregional recurrence infrequently occurs after mastectomy for breast cancer, screening US enables detection of nonpalpable cancer before it can be detected by clinical examination. Routine follow-up US can be advocated for early detection of nonpalpable locoregional recurrent cancer.

Objective To evaluate the efficacy and toxicity of erlotinib in the management of squamous cell carcinoma (SCC) of the vulva. Methods Patients with vulvar lesions amenable to surgery or chemoradiation (cohort 1) or those with metastatic measurable disease (cohort 2) received erlotinib 150mg daily. Patients were monitored for toxicity. Responses were determined by digital photography or RECIST 1.1. Cohort 1 underwent pre and post treatment biopsies. EGFR immunohistochemistry (IHC), fluorescence in-situ hybridization (FISH), and mutational analysis were performed. Results 41 patients were enrolled: 17 in cohort 1 and 24 in cohort 2. Notable grade 3 or 4 toxicities included allergic reaction (1), diarrhea/electrolyte abnormalities (3), ischemic colitis (1), and renal failure (3) and electrolyte abnormalities (n=2). Mean number of cycles for cohort 2 was 3.3. Overall clinical benefit rate was 67.5% with 11 (27.5%) partial responses (PR), 16 (40.0%) stable disease (SD), and 7 (17.5%) progressive disease. Responses were of short duration. All pre and post treatment biopsies exhibited 2–3+ EGFR staining. 5 of 14 patients (35%) were found to have EGFR amplification (n=3) or high polysomy/trisomy (n=2). These five patients had either a PR (n=3) or SD (n=2). Gain of function mutations were not been identified. Conclusions This is the first reported controlled trial evaluating erlotinib for the management of vulvar carcinoma. Toxicities were acceptable given the lack of treatment options for these patients. Given the observed clinical benefits erlotinib may represent one of the most active agents available to treat vulvar SCC.

The photophysical properties of europium-doped calcium titanate for near ultra-violet excitation were studied in order to investigate whether it is applicable to white light-emitting diodes. CaTiO 3 :Eu 3+ phosphors were synthesized by using the solid-state reaction method. The structures and basic properties of the phosphors were characterized by using X-ray diffractometer, scanning electron microscope, UV-visible spectrophotometer, and X-ray photoelectron spectrometer. The photophysical properties were examined by taking excitation and emission spectra. A strong red luminescence corresponding to 5 D 0 → 7 F 2 transition of Eu 3+ under near ultra-violet excitation was observed. It was found that CaTiO 3 :Eu 3+ was a red-emitting phosphor and had higher efficiency for operation under near ultra-violet excitation.

This report introduces an innovative treatment approach of selecting atypical and unconventional teeth for orthodontic extraction without compromising the quality of treatment outcomes by using temporary skeletal anchorage devices in patients with bimaxillary protrusion. Both patients introduced in this report had solid Class I molar relationships with bimaxillary anterior protrusion without facial or dental midline asymmetry. Their chief concerns were significant facial convexity, which conventionally requires the extraction of all 4 first premolars. However, 3 second premolars and 1 first premolar were removed in the first patient, and 2 second premolars and 2 first premolars were removed in the second patient. All second premolars extracted had previously had root canal treatment and large prosthodontic restorations, which resulted in a compromised short lifespan of the teeth relative to the natural dentition. To manage these cases of asymmetric extraction space in a symmetric dental and skeletal environment, 2 mini-implants were placed in the posterior maxillary interradicular spaces, 1 on each side. Despite the unusual asymmetric extraction of teeth, superimposition of the pretreatment and posttreatment cephalometric tracings shows excellent treatment outcomes of facial convexity reduction by asymetric maximum retraction of the anterior teeth with no change in the molar relationships.

Introduction:Reduced lung function is an important risk factor for lung cancer and increases surgical risk in patients with operable stages of lung cancer. Nevertheless, there have been few studies to reveal association of lung function with mortality in patients with advanced lung cancer. The aim of this study was to investigate whether low forced expiratory volume in 1 second (FEV1) is an independent predictor of mortality in patients with advanced lung cancer.Methods:Data were retrospectively collected from patients with non-small cell lung cancer of stage IIIB or IV and available spirometry at diagnosis of lung cancer. They had the last follow-up consecutively between April 2003 and July 2009 in a tertiary referral hospital.Results:Among a total of 156 patients, 118 died as of July 2009. Their mean age was 65 years; 115 (74%) were men. Mean FEV1 was 1.91 liters (79% of predicted). Seventy-one patients (46%) had adenocarcinoma, and 48 (31%) had squamous cell carcinoma. In a multivariate analysis using Cox regression model, independent prognostic factors were FEV1 less than 50% of predicted (hazard ratio [HR] = 2.704, 95% confidence interval [CI]: 1.516–4.823, p = 0.001), chemotherapy (HR = 0.311, 95% CI: 0.192–0.503, p < 0.001), adenocarcinoma (HR = 0.459, 95% CI: 0.300–0.701, p < 0.001), body mass index (HR = 0.921, 95% CI: 0.870–0.975, p = 0.005), and the presence of malignant pleural effusion (HR = 1.673, 95% CI: 1.102–2.540, p = 0.016).Conclusions:Reduced FEV1 is strongly associated with mortality in advanced non-small cell lung cancer.

We report a case of mastitis showing bizarre calcifications in a systemic lupus erythematosus (SLE) patient. A 34-year-old woman had suffered from SLE for 12 years. Initial mammogram showed global asymmetry and extensive linear branching casting calcifications with ductal distribution in the left breast; the image had the appearance of a ductogram. Sonogram showed multiple calcifications without formation of a mass in the left breast. At 5-year follow-up, mammogram revealed large, coarsely conglomerated calcifications in the left breast. The clinical and radiological diagnosis of lupus mastitis was made.

To expand the applications of direct methanol fuel cells (DMFCs), the testing time required to evaluate their durability must be shortened. In this article, we present a step-by-step, accelerated degradation test (ADT) procedure for simple application by fuel cell engineers to the membrane electrode assembly (MEA) in DMFCs. Using MEA degradation data obtained under high stress conditions, we provide a method to estimate the lifetime distribution for normal use conditions and derive optimal testing plans for further degradation tests. A bi-exponential model with random coefficients is introduced to represent the nonlinear deterioration path of the MEAs. Based on the lifetimes estimated from the bi-exponential model at higher temperatures, the lifetime distribution at normal use temperature is extrapolated using the Weibull–Arrhenius model as the lifetime-temperature relationship.

One of the major challenges in direct methanol fuel cells (DMFCs) is to design reliable and stable FC systems that satisfy the very high dynamic demand in various environmental conditions for portable devices. This paper provides an overview of several failure modes and effect analyses (FMEAs) which can have significant consequences on the durability and stability of DMFCs, including high and sub-zero temperature storage, dry and high humidification atmospheres, and fuel/oxidation starvation by breakdown of fuel/air supply components. Firstly, some characterization methods are discussed to investigate changes of membrane electrode assemblies (MEAs) in terms of their physiochemical and electrochemical properties after testing in various simulated failure modes. Secondly, possible mitigating solutions to minimize the hazards associated with them are suggested through a fundamental understanding and scientific approach. The relationship between the causes and symptoms in DMFC systems is determined by examining a variety of failure sources.

This article proposes a new prediction model to describe the nonlinear performance degradation paths of membrane electrode assemblies (MEAs) in direct methanol fuel cell (DMFC): a bi-exponential model with random coefficients. The bi-exponential model is constructed on a mathematical basis representing second-order kinetics. Performance variation between MEAs is incorporated by random coefficients in the proposed model. A likelihood ratio test is sequentially executed to select random effects in the nonlinear random-coefficients model. Analysis results indicate that the reliability estimation can be substantially improved by using the nonlinear random-coefficients model to incorporate two heterogeneous degradation characteristics of MEA performance during continuous operation of DMFC. Confidence intervals of failure-time distributions are obtained by the parametric bootstrap method.

This paper investigates changes in the performance of membrane electrode assemblies (MEAs) of Direct Methanol Fuel Cells (DMFC) that are caused by undergoing storage at −10 °C and 60 °C under different experimental conditions. Storage at 60 °C exhibited negative effects on an MEA’s performance only when storing the MEA at a 4 M CH 3 OH solution. Here, application of a reverse current for 10 s was found to reinstall the original performance. The effect of storage at −10 °C on an MEA’s performance strongly depends upon the MEA’s properties. MEAs are grouped into three different categories with regard to their suitability for low temperature storage: not affected, temporarily affected, irreversibly affected. The temporarily affected MEAs could be instantly and completely reactivated by a reverse current. Changes in the MEA properties that had been caused by being stored at −10 °C were investigated for two MEAs using electrochemical methods, scanning electron microscopy and porosity measurements. The following MEA materials and manufacturing methods had been found to be principally suitable to build MEAs tolerant to storage at −10 °C: the manufacturing methods CCM (catalyst coated on the membrane) and CCS (catalyst coated on the substrate), several hydrocarbon membranes, high Pt and Pt-Ru catalyst loadings. By carefully selecting the proper MEA material, MEAs with tolerance towards low and high storage temperatures can be designed.

Comprehensive and systematic direct methanol fuel cell (DMFC) membrane electrode assembly (MEA) lifetime tests are presented under a wide range of operating conditions including constant voltage, constant current, constant power, and cyclic voltage loading. In this work, the characteristics of the MEA lifetime are strongly dependent on how the DMFC system is managed in a certain operation mode. The degradation ratio of MEAs is strongly dependent on the set voltage/current level in the constant operation mode. In the case of the DMFC constant power operation mode, the trend of MEA performance degradation shows the combined effect of both constant voltage and constant current operation mode, due to the required current increases to maintain the specified power output with time, while the voltage has the downward tendency from the initial value. The DMFC performance degradation under cyclic voltage loading (on–off) mode is much more severe than that of continuous voltage and current operation, while there is little difference between continuous voltage and current mode designs. The potential degradation mechanisms are proposed at each operating condition and demonstrated by using various electrochemical analysis techniques including impedance spectroscopy and polarization curves for improving long-term operational stability through mitigating such deterioration mechanisms of MEAs.

A membrane electrode assembly (MEA) that is a combination of a catalyst-coated membrane (CCM) for the anode and a catalyst-coated substrate (CCS) for the cathode is studied under air-blower conditions for direct methanol fuel cells (DMFCs). Compared with MEAs prepared by only the CCS method, the performance of DMFC MEAs employing the combination method is significantly improved by 30% with less methanol crossover. This feature can be attributed to an enhanced electrode|membrane interface in the anode side and significantly higher catalyst efficiency. Furthermore, DMFC MEAs designed by the combination method retain high power density without any degradation, while the CCM-type cell shows a downward tendency in electrochemical performance under air-blower conditions. This may be due to MEAs with CCM have a much more difficult structure of catalytic active sites in the cathode to eliminate the water produced by electrochemical reaction. In addition, DMFCs produced via combination methods exhibit a lower water crossover flux than CCS alternatives, due to the comparatively dense structure of the CCM anode. Hence, DMFCs with a combination MEA structure demonstrate the feasibility of a small fuel cell system employing the low noise of a fan, instead of a noisy and large capacity air pump, for portable electronic devices.

Mass balance research in direct methanol fuel cells (DMFCs) provides a more practical method in characterizing the mass transport phenomena in a membrane electrode assembly (MEA). This method can be used to measure methanol utilization efficiency, water transport coefficient (WTC), and methanol to electricity conversion rate of a MEA in DMFCs. First, the vital design parameters of a MEA are recognized for achieving high methanol utilization efficiency with increased power density. In particular, the structural adjustment of anode diffusion layer by adding microporous layer (MPL) is a very effective way to decrease WTC with reduced methanol crossover due to the mass transfer limitation in the anode. On the other hand, the cathode MPL in the MEA design can contribute in decreasing methanol crossover. The change of structure of cathode diffusion layer is also found to be a very effective way in improving power density. In contrast, the WTC of DMFC MEAs remains virtually constant in the range of 3.4 and 3.6 irrespective of the change of the cathode GDL. The influence of operating condition on the methanol utilization efficiency, WTC, and methanol to electricity conversion rate is also presented and it is found that these mass balance properties are strongly affected by temperature, current density, methanol concentration, and the stoichiometry of fuel and air.

Relaxor ferroelectric PbMg 1/3 Nb 2/3 O 3 (65%)–PbTiO 3 (35%) (PMN–35PT) thin films were grown by a sol–gel method on Pt(1 1 1)/TiO 2 /SiO 2 /Si(1 0 0) substrates. Piezoresponse and poling behavior appear to have a relation with the relaxor behavior of the materials. Piezoelectric images were studied in a number of regions on the films with subsequent statistical analysis of the obtained data using the contact mode of scanning force microscopy. Hysteresis loops were observed with external field applied over a wide range of the vibration frequency. The piezoelectric coefficient, d 33 , and the crystallographic electrostrictive constant, Q 33 , were also determined as 100 pm/V and 2.8×10 −3 C −2 m 4 , respectively.

Summary Background This study was undertaken to identify the determinants of respiratory symptom development in patients with chronic airflow obstruction (CAO). Methods Categories of symptomatic and asymptomatic CAO were defined using questionnaire responses and spirometric results. We analyzed data obtained as part of the second South Korean National Health and Nutrition Examination Survey (Korean NHANES II). Results Among 187 patients with CAO, 69 had no respiratory symptoms. CAO patients with symptoms were significantly older than those without symptoms \( P = 0.026 \) , and hypertension was more common among symptomatic CAO patients than among asymptomatic CAO patients \( P = 0.005 \) . According to questionnaire responses, symptomatic CAO patients had more difficulty in walking or lifting \( P 0.001 \) , required more help with personal care \( P = 0.01 \) , and had poorer general health than asymptomatic CAO patients \( P = 0.008 \) . Symptomatic CAO patients had higher fasting blood glucose levels than asymptomatic CAO patients \( P = 0.028 \) . Symptomatic CAO patients had significantly lower forced expiratory volume in 1s (FEV 1 ) \( P = 0.001 \) , forced vital capacity (FVC) \( P = 0.008 \) , and a ratio of FEV 1 /FVC than asymptomatic CAO patients \( P 0.001 \) . Statistically significant predictors of symptom development were as follows: age (odds ratio (OR) 1.04, P = 0.028 ), hypertension (OR 4.41, P = 0.008 ), fasting blood glucose (OR 1.02, P = 0.034 ), FEV 1 (OR 0.07, P = 0.002 ), FVC (OR 0.08, P = 0.009 ), FEV 1 /FVC (OR 0.00, P = 0.001 ). Multiple logistic regression analyses revealed two independent factors associated with symptom development: FEV 1 /FVC (OR 0.001, P = 0.002 ) and hypertension (OR 5.95, P = 0.005 ). Conclusions In CAO, respiratory symptom development is significantly associated with low FEV 1 /FVC and the presence of hypertension.

Study objectives To assess the diagnostic values of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 19 fragments (CYFRA 21–1) as markers of pleurisy in primary lung cancer. Design Prospective case-control study. Setting A tertiary university hospital. Patients Thirty-four patients with lung cancer and 16 patients with tuberculous pleurisy. Measurements and results Levels of CEA, NSE, and CYFRA 21–1 were measured by immunoassay in the serum and pleural fluid of patients with lung cancer and of patients with tuberculous pleurisy. Patients with lung cancer were found to have significantly higher serum and pleural fluid levels of CEA and CYFRA 21–1 than patients with tuberculous pleurisy. Using cutoff values of 5 ng/mL, 20 ng/mL, and 3.3 ng/mL for serum CEA, NSE, and CYFRA 21–1, respectively, the sensitivities and specificities of these tumor markers were as follows for differentiating malignant effusion from benign: CEA, 68% and 93%; NSE, 34% and 93%; and CYFRA 21–1, 45% and 100%. Using cutoff values of 5 ng/mL, 20 ng/mL, and 45 ng/mL for pleural fluid, the sensitivities and specificities were as follows: CEA, 82% and 94%; NSE, 36% and 94%; and CYFRA 21–1, 61% and 81%. A combination of pleural fluid CEA and NSE increased sensitivity and specificity. Conclusions In the diagnosis of malignant effusion associated with lung cancer, the determinations of CEA and NSE in pleural fluid could enhance diagnostic yield better than those of all three tumor markers.

Revised JPN guidelines for the management of acute pancreatitis: JPN guidelines 2015 Toshihiko Mayumi, Tadahiro Takada, Masamichi Yokoe, Masahiro Yoshida University of Occupational and Environmental Health, Japan Teikyo University School of Medicine, Japan Japanese Red Cross Nagoya Daini Hospital, Japan Clinical Research Center Kaken Hospital, International University of Health and Welfare, Japan Background/Purpose: JPN guidelines for the management of acute pancreatitis were published in 2003 and revised in 2007 and 2009 that the severity assessment score has been highly regarded all over the world. Since the classification and the definition of acute pancreatitis had been changed significantly in the New Atlanta classification of acute pancreatitis 2012, the working group of JPN guidelines revised JPN guidelines with making new meta-analysis and using the GRADE system. Methods: The working group of revising JPN guidelines consists of 28 specialists, surgeons, gastroenterologists, endoscopists, radiologists, and epidemiologists. Results: JPNguidelines 2015 containmajor topics as described below: (1) epidemiology and etiology, (2) diagnostic criteria, (3) severity scoring system, (4) fundamental and intensive care with flowcharts, (5) therapeutic intervention and surgery, (6) post-ERCP pancreatitis, (7) treatment strategy, (8) clinical indicator andpancreatitis bundles, and (9) imaging. JPN guidelines also released mobile applications for the management of acute pancreatitis. Meta-analyses were performed on prophylactic antibiotic use for the prevention of necrotizing pancreatitis and reduction of mortality and on prophylactic pancreatic stent placement for the prevention of post-ERCP pancreatitis. These metaanalysis data have the results that significant effects are expected to each setting. JPN guidelines 2015 take advantage of this brand-new evidence for the new idea for the treatment of acute pancreatitis. Conclusions: Revised JPN guidelines 2015 achieve further evolution with new meta-analysis data and contain a lot of recommendations using the GRADE system for clinical use.

To expand commercial applications of polymer electrolyte membrane fuel cells (PEMFCs), the evaluation time for their durability must be shortened. This article provides a straightforward accelerated degradation testing (ADT) procedure for PEMFC for easy and quick implementation of the procedure. The ADT procedure includes statistical modeling of degradation patterns of membrane electrode assemblies (MEAs) in PEMFCs under startup–shutdown cycling conditions. For this purpose, we propose a nonparametric degradation model to describe the nonlinear performance degradation paths of PEMFC MEAs. The analysis results indicate that the nonparametric approach provides more accurate estimates of the observed degradation data than other parametric approaches. Based on the nonparametric degradation model, we suggest a method to predict failure-times under normal operating conditions by estimating the time-scale factor under accelerated operating conditions.

Purpose To report a case of minimal change nephrotic syndrome (MCNS) after photodynamic therapy using verteporfin. Design Interventional case report. Methods After four cycles of photodynamic therapy, general weakness with generalized edema developed in an otherwise healthy 66-year-old woman, resulting in dyspnea and ascites. Urinalysis showed heavy proteinuria (4+) with decreased serum total protein and albumin, and increased total cholesterol levels, suggesting nephrotic syndrome. Renal biopsy and pathologic diagnosis were performed. Results Renal biopsy revealed normal glomeruli and tubulointerstitium by light microscopy, with no immunoglobin or complement deposition. Transmission electron microscopy showed diffuse effacement of the foot processes of visceral epithelial cells, which is the characteristic finding of minimal change nephrotic syndrome. Conclusions We herein report a case of minimal change nephrotic syndrome after photodynamic therapy using verteporfin.

Background : As number of the older patients for general elective surgery is increasing, postoperative pulmonary complications in the elderly are common and are a significant source of morbidity and mortality. Methods : We retrospectively evaluated the incidence and predictors of postoperative pulmonary complications in 206 patients of 65 years old or more who underwent general elective nonthoracic surgery. Postoperative pulmonary complications were defined as newly developed atelectasis, pneumonia, pulmonary thromboembolism and acute respiratory failure requiring mechanical ventilation following surgery. Results : There were 28 (13.6%) postoperative pulmonary complications. Statistically significant predictors of pulmonary complications were as follows: underlying lung disease (odds ratio, 3.2; p