Jiwoon Song

Phase-dependent thermal conductivity of Ge1Sb4Te7 and N: Ge1Sb4Te7 for phase change memory applications

We report the thermal conductivities of Ge1Sb4Te7 and nitrogen-doped Ge1Sb4Te7 thin films at temperatures ranging from 300 to 520 K using the 3ω method. Thermal conductivity of Ge1Sb4Te7 increases abruptly during the transition from the amorphous to crystalline phase. Nitrogen doping effectively suppresses the crystallization process, resulting reduction of lattice as well as electronic thermal conductivity. These behaviors are confirmed by x-ray diffraction, sheet conductance, and thermal conductivity measurements. Numerical modeling of phase change memory device shows that with nitrogen doping, performance increase in terms of lower reset current and faster reset time can be achieved.

A facile route for the fabrication of large-scale gate-all-around nanofluidic field-effect transistors with low leakage current{

Active modulation of ions and molecules via field-effect gating in nanofluidic channels is a crucial technology for various promising applications such as DNA sequencing, drug delivery, desalination, and energy conversion. Developing a rapid and facile fabrication method for ionic field-effect transistors (FET) over a large area may offer exciting opportunities for both fundamental research and innovative applications. Here, we report a rapid, cost-effective route for the fabrication of large-scale nanofluidic field-effect transistors using a simple, lithography-free two-step fabrication process that consists of sputtering and barrier-type anodization. A robust alumina gate dielectric layer, which is formed by anodizing sputtered aluminium, can be rapidly fabricated in the order of minutes. When anodizing aluminium, we employ a hemispherical counter electrode in order to give a uniform electric field that encompasses the whole sputtered aluminium layer which has high surface roughness. In consequence, a well-defined thin layer of alumina with perfect step coverage is formed on a highly rough aluminium surface. A gate-all-around nanofluidic FET with a leak-free gate dielectric exhibits outstanding gating performance despite a large channel size. The thin and robust anodized alumina gate dielectric plays a crucial role in achieving such excellent capacitive coupling. The combination of a gate-all-around structure with a leak-free gate dielectric over a large area could yield breakthroughs in areas ranging from biotechnology to energy and environmental applications.

Thermal Stress Analysis of

Due to the extreme operating conditions in phase-change memory (PCM) cells in terms of temperature and heating/cooling rate, thermal stress is regarded as one of the most critical problems in PCM devices. Here, we report on the thermal stress analysis of Ge1Sb4Te7-based PCM cells using numerical simulations. Thermomechanical properties are measured prior to the thermal stress analysis, where the Youngs modulus, thermal expansion coefficient, and density of (poly)crystalline Ge1Sb4Te7 are measured to be 37.8 GPa, 17.913 × 10-6 K-1, and 5685 kg · m-3, respectively. Transient thermal stress evolution in conventional T-structured and trench depth-varying PCM cells is simulated during the reset process. For the T-structured PCM cell, thermal stress is developed largely in the interface of the phase-change and bottom contact layers (PCL and BCL respectively), which may lead to the delamination of the PCL from the metal electrode. However, we observe that, as the trench depth is increased, the thermal stress along the interface of the PCL and the interlayer dielectric (ILD) also increases. Therefore, in a deep-trenched PCM cell, a possible thermal failure is likely to occur not only at the interface of the PCL and the BCL but also at the interface of the PCL and the ILD.

\hbox{Ge}_{1}\hbox{Sb}_{4} \hbox{Te}_{7}

The present experiment has been conducted to investigate effects of a recirculation zone at a multi-slot film cooling system in a ramjet combustor. The tested model is a pre-diffuser typed ramjet combustor having a recirculation zone due to the large expansion duct. The recirculation zone directly affects on the film cooling effectiveness and heat transfer coefficient at the first two slots of multi-slot system. Results from experiments are divided into two flow regions - a recirculation region and a boundary layer developing region. In the former region, the film cooling effectiveness decreases rapidly due to the mixing effect by a shear layer between the recirculation flow and the injected coolant from the slot. In the later cases, the lip thickness to slot height ratio is a main factor on film cooling effectiveness due to the generated eddies behind the back step of slot lip. As the blowing rate increases, the film cooling effectiveness is enhanced for all cases due to the augmented momentum of injected coolant from the slot

-Based Phase-Change Memory Devices

We investigated renal outcome of kidney-transplantation in 19 Korean recipients with biopsy-proven lupus nephritis and compared it with 18 Korean age- and gender-matched recipients without lupus nephritis who were diagnosed with end-stage renal disease caused by renal diseases other than lupus nephritis in a single centre. We reviewed histological findings of kidneys and calculated cumulative dose of immunosuppressive agents. We assessed renal flare of systemic lupus erythematosus, recurrence of lupus nephritis and graft failure as prognosis. The mean age of recipients with lupus nephritis was 43.5 years and all patients were female. Six patients had class III, 10 had class IV and three had class V. There were no meaningful differences in demographic data, renal replacement modality, cumulative doses of immunosuppressants and prognosis between recipients with and without lupus nephritis. Eight patients experienced renal flare of systemic lupus erythematosus, but there were no cases of recurrence of lupus nephritis or graft failure in recipients with lupus nephritis. Kidney-recipients with class IV lupus nephritis exhibited a lower cumulative renal flare of systemic lupus erythematosus free survival rate than those with class III lupus nephritis. In conclusion, renal outcome of kidney-transplantation in patients with lupus nephritis is similar to that in those without lupus nephritis, and class IV was associated with renal flare of systemic lupus erythematosus.

Heat Transfer Measurement on Slot Film Cooling of Ramjet Combustor

Serum Mac-2-binding protein (M2BP) is elevated in various chronic inflammatory diseases, and evidence suggests that glycosylation of M2BP induces discrete biological effects. However, the role of serum M2BP in systemic lupus erythematosus (SLE) is still unclear. Recently, a Wisteria floribunda agglutinin-positive–M2BP (WFA+–M2BP) immunoassay has shown promise in detecting highly glycosylated M2BP. In this study, by using WFA+–M2BP immunoassay, we measured serum M2BP in 203 SLE patients and evaluated its clinical significance. Eighty patients were classified as having active SLE and 123 patients as having inactive SLE. The median serum M2BP was higher in patients with active SLE than in those with inactive SLE (2.1 vs. 0.9, p < 0.001). In multivariate linear regression analysis, serum M2BP, anti-dsDNA, C3 and erythrocyte sedimentation rate (ESR) were associated with SLEDAI-2K. Serum M2BP also strongly correlated with laboratory variables related to SLEDAI-2K, ESR and C-reactive protein. Furthermore, multivariate logistic regression analysis demonstrated that serum M2BP was useful in predicting active SLE. Finally, following immunosuppressive treatment, elevated serum M2BP significantly decreased along with improvement in disease activity. These findings suggest that serum M2BP might contribute to the inflammatory process in SLE, and measuring serum M2BP might be a useful marker to assess SLE disease activity.

Renal outcome after kidney-transplantation in Korean patients with lupus nephritis.

ABSTRACT Infrared(IR) guided heat-seeking missiles uses IR emissions from aircraft to detect and track a target. Due to passive characteristic of the IR guidance, early detection of the missile is difficult and it is significant threat to aircraft survivability. Therefore, IR signature prediction of the aircraft is an important aspect of the stealth technology. In this study, we simulated IR signature of the aircraft in real atmospheric conditions. Aircraft surface temperature distribution was calculated by using RadthermIR code. Based on temperature distribution, IR radiance and BRDF(Bidirectional Reflectance Distribution Function) image were simulated for different weather(seasonal) and background(sky/soil) conditions. The IR contrast tendencies are not aligned with surface temperature or magnitude of target IR radiance. Therefore, it is essential to simulate IR signature with various conditions and background to acquire reliable database.Key Words : IR Stealth(적외선 스텔스), Surface Temperature(표면온도), Aircraft IR Signature(항공기 적외선신호), Atmospheric/Background Conditions(대기/배경 조건)

Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein can reflect systemic lupus erythematosus activity:

Background The prognostic nutritional index (PNI), which was first introduced by Onodera et al., is calculated based on the serum albumin level and total lymphocyte count in the peripheral blood. It is proposed to be a parameter to reflect immunonutritional status, however, it is also known that albumin and lymphocyte count may decrease in proportion to inflammatory burdens in autoimmune diseases. Objectives We investigated whether PNI at diagnosis can be used for estimating BVAS at diagnosis in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) patients. Methods We retrospectively reviewed the medical records of 160 patients with AAV. We calculated Birmingham vasculitis activity score (BVAS). We collected laboratory results including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), while blood cell, lymphocyte and platelet counts and serum albumin. Prognostic nutritional index (PNI) was calculated by (10 x serum albumin (g/dl)+0.005 x lymphocyte count (/mm3)). The association was assessed linear regression analyses. The optimal cut-off of PNI for predicting relapse was set at 36.6. Comparison of cumulative relapse free survival was analysed by the Kaplan-Meier survival analysis. Results The mean age at diagnosis was 55.2 years and 48 patients were male. Eighty-five patients had MPA, 41 patients had GPA and 34 patients had EGPA. The mean BVAS and PNI at diagnosis were 11.9 and 43.4. Forty-three patients experienced relapse of AAV. In univariable linear regression analysis, BVAS was positively correlated with ESR and CRP and was negatively correlated with lymphocyte count, serum albumin level and PNI. In multivariable analysis, BVAS was the most significantly associated with only PNI (standardised β=−0.296). Patients having PNI at diagnosis ≤36.6 exhibited significantly lower cumulative relapse free survival rate than those having PNI at diagnosis >36.6 (p=0.002).Abstract SAT0547 – Table 3 Univariable linear regression analysis of BVAS and continuous variables in 160 patients with AAV Univariable analysis RegressionCoefficient(Crude B) CorrelationCoefficient(R=β) p value Demographic data at diagnosis Age (year old) 0.027 0.053 0.504 Acute reactants at diagnosis ESR (mm/hr) 0.044 0.218 0.006 CRP (mg/L) 0.023 0.169 0.033 Laboratory results reflecting inflammation at diagnosis White blood cell count (/mm3) 0.000 0.104 0.189 Lymphocyte count (/mm3) −0.002 −0.214 0.007 Platelet count (x1,000/mm3) 0.003 0.060 0.449 Serum albumin (g/dL) −2.557 −0.262 0.001 PNI −0.252 −0.307 <0.001 BVAS: Birmingham vasculitis activity score; ANCA: antineutrophil cytoplasmic antibody; AAV: ANCA associated vasculitis; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; PNI: prognostic nutritional index.Abstract SAT0547 – Figure 2 The association of PNI at diagnosis with relapse of AAV during the follow-up. We selected the optimal cut-off of PNI at 36.6, divided patients into two groups according to the cut-off and conducted Kaplan-Meier survival analysis. Patients having PNI at diagnosis ≤36.6 exhibited significantly lower cumulative relapse free survival rate than those having PNI at diagnosis >36.6 (p=0.002). PNI: prognostic nutritional index; AAV: antineutrophil cytoplasmic antibody. Conclusions PNI at diagnosis can be used to estimate BVAS at diagnosis and PNI at diagnosis ≤36.6 may predict relapse during the follow-up in AAV patients. References [1] Nihon Geka Gakkai Zasshi1984;85:1001–5. [2] J Cancer Res Clin Oncol Oncol2014;140:1537–49. [3] Arthritis Rheum2013;65:1–11. Acknowledgements None. Disclosure of Interest None declared

IR Characteristics of an Aircraft in Different Atmospheric/Background Conditions

Background Inflammasomes are cytoplasmic multiprotein complexes that recognise various exogenous and endogenous danger signals in myeloid cells, particularly macrophages. Inflammasome activation eventually induces inflammatory responses in macrophages by activating gasdermin-d-mediated pyroptosis and the secretion of pro-inflammatory cytokines including interleukin (IL)−1β and IL-18 in a caspase-1-dependent manner. The production of IL-1 has been found to be highly induced in AS1 and caspase-1 level was significantly elevated in spondyloarthritis patients than in those with other arthritic diseases,2 suggesting the possibility that inflammasomes might be involved in pathogenesis of ankylosing spondylitis (AS). However, few studies have addressedd the roles of inflammasomes in AS. Objectives This study was performed to investigate the role of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in the peripheral blood mononuclear cells (PBMCs) from AS patients. Methods PBMCs from 11 patients and 9 healthy controls were isolated and mRNA expression levels of NLRP3 inflammasome, pro-IL-1β, IL-1β, pro-caspase-1, and caspase-1 were determined using quantitative real-time PCR. IL-17A (100 ng/mL) was added to the cell cultures, then, cytokine expression, signalling pathways, and inflammasome machinery are determined using real-time RT-PCR and Western blot. After transfection of siNLRP3 to AS PBMCs, mRNA and proteins levels of IL-1β and caspase-1 were determined using real time PCR and western blot. Results Expressions of NLRP3, IL-1β, and caspase-1 mRNAs, but not IL-18, were increased in PBMCs from AS patients compared to controls. Incubation of AS PBMCs with IL-17A significantly increased NLRP3, IL-1β, IL-18, and caspase-1 expressions in AS PBMCs. Western blot showed IL-17A treatment induced the phosphorylation of Akt, p38 MAPK, and NF-κB p65 in AS PBMCs. Down-regulation of NLRP3 by transfection of siRNA decreased mRNA expressions and productions of IL-1β and caspase-1 in AS PBMCs. Conclusions Activity of NLRP3 inflammasome was increased in AS patients and IL-17A potentiated the activation of NLRP3 inflammasome. Our data suggest the possible role of NLRP3 inflammasome in inflammatory response in AS. References [1] Tan AL, Marzo-Ortega H, O’Connor P, Fraser A, Emery P, McGonagle D. Efficacy of anakinra in active ankylosing spondylitis: a clinical and magnetic resonance imaging study. Ann Rheum Dis. 2004;63:1041–1045. [2] Son CN, Bang SY, Kim JH, Choi CB, Kim TH, Jun JB. Caspase-1 level in synovial fluid is high in patients with spondyloarthropathy but not in patients with gout. J Korean Med Sci. 2013;28:1289–1292. Disclosure of Interest None declared

SAT0547 Prognostic nutritional index for estimating birmingham vasculitis activity score in anca-associated vasculitis

Background The most important differential diagnoses of acute monoarticular arthritis are septic arthritis and acute gout attack. Identifying infection is crucial in preventing the devastating outcome of septic arthritis. Objectives The delta neutrophil index (DNI) is a value that corresponds to the fraction of circulating immature granulocytes. As DNI reflects the burden of infection, we evaluated this index as a differentiating marker between septic arthritis and acute gout attack. Methods The medical records of 149 patients with septic arthritis and 194 patients with acute gout attack were reviewed. A specific cell analyser, ADVIA 2120, was used to measure DNI. Clinical and laboratory markers associated with predicting septic arthritis were assessed by using logistic regression. Results Patients with septic arthritis showed higher levels of DNI than those with acute gout attack (3.3 vs. 0.6%, P<0.001). Similar results were observed in patients without monosodium urate (MSU) crystal confirmation or those with normouricemia (3.3 vs. 0.5 and 3.1 vs. 0.7%, respectively; P <0.001 for both). A DNI level of 1.9% was determined as the cut-off value for predicting septic arthritis. In the multivariate analysis, DNI was the most powerful independent value for predicting septic arthritis (odds ratio 14.003).Table 1. Comparison of variables between patients with acute gout attack and those with septic arthritis Variables Patients with acute gout attack (n=194) Patients with septic arthritis (n=149) Total (n=343) p-value Age, years 65.0±15.0 60.9±16.4 63.2±15.8 0.016 MSU crystals confirmed, n (%) 81 (41.8%) N/A 81 (23.6%) N/A Positive culture, n (%) N/A 98 (65.8%) 97 (28.3%) N/A WBC count, /mm3 9600.0±3000.0 11,200.0±4700.0 10,300.0±3900.0 <0.001 DNI, % 0.6±0.9 3.3±4.0 1.8±3.0 <0.001 ESR, mm/h 61.7±33.8 78.2±32.5 69.3±34.2 <0.001 CRP, mg/L 76.5±68.7 126.6±104.0 98.7±89.6 <0.001 BUN, mg/dL 29.5±21.9 22.7±14.7 26.6±19.4 0.001 Creatinine, mg/dL 1.9±1.9 1.2±1.7 1.6±1.8 <0.001 Uric acid, mg/dL 7.6±2.5 4.4±1.6 6.3±2.7 <0.001Table 2. Multivariate analysis of the predictive values for septic arthritis in patients with acute gout attack and those with septic arthritis* Variables Odds ratio 95% Confidence interval p-value WBC count ≥14,000.0/mm3 1.888 0.563, 6.337 0.303 DNI ≥1.9% 14.003 5.683, 34.508 <0.001 ESR ≥70.0 mm/h 2.505 1.109, 5.657 0.027 CRP ≥106.0 mg/L 3.032 1.276, 7.209 0.012 Uric acid ≥7.0 mg/dL 0.031 0.011, 0.086 <0.001 Conclusions This study showed the possibility of using DNI as a differentiating marker between septic arthritis and acute gout attack at the crucial early phase. DNI showed its relevance regardless of confirmation of MSU crystal deposition or serum level of uric acid. Disclosure of Interest None declared