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ABSTRACTCovariance matrix estimation is of great importance in formulating a portfolio. The sample covariance matrix, the most frequently used estimator, is well known to be unstable due to the estimation error, when the sample size is small. A shrinkage approach is one of the popular methods for estimating a stable covariance matrix. This study compares and evaluates performance of the three different shrinkage type covariance matrix estimators for the optimal portfolio selection strategy. To evaluate the performance of the covariance matrix estimators, we consider both the in- and out-of-sample value at risk, conditional value at risk, Sharpe-ratio, adjusted Sharpe-ratio, and a beta of the portfolio selection strategies. Empirical results show that a portfolio using shrinkage covariance matrix estimator with the identity matrix or constant correlation matrix as the shrinkage target tends to have a lower risk. We also find that the random matrix approach has a relatively high out-of-sample return and Sharpe-ratio under the small sample size cases.

Purpose A daily quality assurance (QA) check in proton therapy is ensuring that the range of each proton beam energy in water is accurate to 1 mm. This is important for ensuring that the tumor is adequately irradiated while minimizing damage to surrounding healthy tissue. It is also important to verify the total charge collected against the beam model. This work proposes a time-efficient method for verifying the range and total charge of proton beams at different energies using a multilayer Faraday collector (MLFC).Methods We used an MLFC-128-250 MeV comprising 128 layers of thin copper foils separated by thin insulating KaptonTMlayers. Protons passing through the collector induce a charge on the metallic foils, which is integrated and measured by a multichannel electrometer. The charge deposition on the foils provides information about the beam range.Results Our results show that the proton beam range obtained using MLFC correlates closely with the range obtained from commissioning water tank measurements for all proton energies. Upon applying a range calibration factor, the maximum deviation is 0.4 g/cm2. The MLFC range showed no dependence on the number of monitor units and the source-to-surface distance. Range measurements collected over multiple weeks exhibited stability. The total charge collected agrees closely with the theoretical charge from the treatment planning system beam model for low- and mid-range energies.Conclusions We have calibrated and commissioned the use of the MLFC to easily verify range and total charge of proton beams. This tool will improve the workflow efficiency of the proton QA.

An assessment of the relative efficacy and tolerability of tofacitinib, baricitinib, upadacitinib, and filgotinib compared to those of methotrexate (MTX) was performed in disease-modifying antirheumatic drug (DMARD)-naive patients with rheumatoid arthritis (RA). We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) so as to examine the efficacy and safety of tofacitinib, baricitinib, upadacitinib, filgotinib, and MTX in DMARD-naïve RA patients. Four RCTs comprising 2185 patients met the inclusion criteria. The ranking probability based on the surface under the cumulative ranking curve (SUCRA) indicated that upadacitinib 15 mg had the highest probability of achieving the American College of Rheumatology 20% (ACR20) response rate, followed by baricitinib 4 mg, tofacitinib 5 mg, filgotinib 200 mg, and MTX. Tofacitinib, baricitinib, upadacitinib, and filgotinib treatments achieved significantly higher ACR50 and ACR70 responses compared to MTX. Tofacitinib 5 mg had the highest probability of achieving the ACR50 and ACR70 response rates, followed by upadacitinib 15 mg, baricitinib 4 mg, filgotinib 200 mg, and MTX. The safety analysis based on serious adverse events, adverse events (AEs), and withdrawals due to AEs revealed no statistically significant differences between the respective intervention groups. In conclusion, tofacitinib, baricitinib, upadacitinib, and filgotinib were effective treatment options for DMARD-naïve RA patients, suggesting a difference in efficacy and safety among the different JAK inhibitors.

Byline: F. Meng, J. Lee, G. Peng, Y. Sung Sir, Combined oral contraceptives (COCs) are often prescribed for the treatment of acne in women. [sup][1] Diane-35-a combination of ethinylestradiol (35 [...]

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p< 5 × 10−8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Naphthalene diimide (NDI)-based conjugated polymers with bithiophene or dithienylethene (TVT) units can form large crystal domains through NDI-driven self-assembly and are widely used in organic electronic devices as n-type materials. However, improving electron transport in these semiconducting polymers has been a significant challenge mainly due to poor electrical connections between the crystal domains. Formation of an interconnected network of small domains with short-range ordering and mixed orientations could be an effective way of increasing the electron mobility (μe) of polymeric materials. The present study demonstrates the feasibility of this approach using an NDI-based polymer composed of fluorinated TVT (FTVT) units. The FTVT unit enhances intermolecular interactions between the polymer chains, leading to robust aggregation. This aggregation was found to suppress NDI-driven self-assembly, resulting in interconnected small crystal domains with short-range ordering and good thermal stability at elevated temperatures. This microstructure provided transistor devices with improved μeby lowering energetic disorder as well as consistent electrical connectivity at different annealing temperatures.

gpGrouper is a gene-centric peptide inference and quantitation algorithm that prevents gene origin mixing and isoform omission in parsimonious protein-centric approaches. A simple classification schema indicates distinguishable gene products, with shared peptide quantities distributed by ratios of corresponding unique peptides. This approach accurately determines tumor content and deconvolution of proteomes from mixed species patient derived xenografts without elimination of species-shared peptides. iBAQ quantities are calculated from label-free, isotopic, or isobaric data, allowing comparisons within and across samples and methodologies.

Fibrosis after solid organ transplantation is considered an irreversible process and remains the major cause of graft dysfunction and death with limited therapies. This remodeling is characterized by aberrant accumulation of contractile myofibroblasts that deposit excessive extracellular matrix (ECM) and increase tissue stiffness. Studies demonstrate, however, that a stiff ECMitself promotes fibroblast‐to‐myofibroblast differentiation, stimulating further ECMproduction. This creates a positive feedback loop that perpetuates fibrosis. We hypothesized that simultaneously targeting myofibroblast contractility with relaxin and ECMstiffness with lysyl oxidase inhibitors could break the feedback loop, reversing established fibrosis. To test this, we used the orthotopic tracheal transplantation (OTT) mouse model, which develops robust fibrotic airway remodeling. Mice with established fibrosis were treated with saline, mono‐, or combination therapies. Although monotherapies had no effect, combining these agents decreased collagen deposition and promoted re‐epithelialization of remodeled airways. Relaxin inhibited myofibroblast differentiation and contraction in a matrix‐stiffness–dependent manner through prostaglandin E2(PGE2). Furthermore, the effect of combination therapy was lost in PGE2receptor knockout and PGE2‐inhibited OTTmice. This study revealed the important synergistic roles of cellular contractility and tissue stiffness in the maintenance of fibrotic tissue and suggests a new therapeutic principle for fibrosis. In an orthotopic tracheal transplant mouse model, targeting two components of the biophysical microenvironment—namely, myofibroblast contractility and extracellular matrix stiffness—can break the autocrine‐fibrogenic positive feedback loop to facilitate self‐repair and attenuate airway fibrosis.

Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme involved in NAD+ biosynthesis. Although NAMPT has emerged as a critical regulator of metabolic stress, the underlying mechanisms by which it regulates metabolic stress in cancer cells have not been completely elucidated. In this study, we determined that breast cancer cells expressing a high level of NAMPT were resistant to cell death induced by glucose depletion. Furthermore, NAMPT inhibition suppressed tumor growth in vivoin a xenograft model. Under glucose deprivation conditions, NAMPT inhibition was found to increase the mitochondrial reactive oxygen species (ROS) level, leading to cell death. This cell death was rescued by treatment with antioxidants or NAD+. Finally, we showed that NAMPT increased the pool of NAD+ that could be converted to NADPH through the pentose phosphate pathway and inhibited the depletion of reduced glutathione under glucose deprivation. Collectively, our results suggest a novel mechanism by which tumor cells protect themselves against glucose deprivation-induced oxidative stress by utilizing NAMPT to maintain NADPH levels.

Background:: To identify loci associated with abdominal fat and replicate prior findings, we performed genome-wide association (GWA) studies of abdominal fat traits: subcutaneous adipose tissue (SAT); visceral adipose tissue (VAT); total adipose tissue (TAT) and visceral to subcutaneous adipose tissue ratio (VSR). Subjects and Methods:: Sex-combined and sex-stratified analyses were performed on each trait with (TRAIT–BMI) or without (TRAIT) adjustment for body mass index (BMI), and cohort-specific results were combined via a fixed effects meta-analysis. A total of 2513 subjects of European descent were available for the discovery phase. For replication, 2171 European Americans and 772 African Americans were available. Results:: A total of 52 single-nucleotide polymorphisms (SNPs) encompassing 7 loci showed suggestive evidence of association (P&lt;1.0 × 10-6) with abdominal fat in the sex-combined analyses. The strongest evidence was found on chromosome 7p14.3 between a SNP near BBS9gene and VAT (rs12374818; P=1.10 × 10-7), an association that was replicated (P=0.02). For the BMI-adjusted trait, the strongest evidence of association was found between a SNP near CYCSP30and VAT–BMI (rs10506943; P=2.42 × 10-7). Our sex-specific analyses identified one genome-wide significant (P&lt;5.0 × 10-8) locus for SAT in women with 11 SNPs encompassing the MLLT10, DNAJC1and EBLN1genes on chromosome 10p12.31 (P=3.97 × 10–8to 1.13 × 10-8). The THNSL2gene previously associated with VAT in women was also replicated (P=0.006). The six gene/loci showing the strongest evidence of association with VAT or VAT-BMI were interrogated for their functional links with obesity and inflammation using the Biograph knowledge-mining software. Genes showing the closest functional links with obesity and inflammation were ADCY8and KCNK9, respectively. Conclusions:: Our results provide evidence for new loci influencing abdominal visceral (BBS9, ADCY8, KCNK9) and subcutaneous (MLLT10/DNAJC1/EBLN1) fat, and confirmed a locus (THNSL2) previously reported to be associated with abdominal fat in women.

The risk of developing post-traumatic osteoarthritis (PTOA) following joint injury is high. Furthering our understanding of the molecular mechanisms underlying PTOA and/or identifying novel biomarkers for early detection may help to improve treatment outcomes. Increased expression of integrin α1β1 and inhibition of epidermal growth factor receptor (EGFR) signaling protect the knee from spontaneous OA; however, the impact of the integrin α1β1/EGFR axis on PTOA is currently unknown. We sought to determine metabolic changes in serum samples collected from wild-type and integrin α1-null mice that underwent surgery to destabilize the medial meniscus and were treated with the EGFR inhibitor erlotinib. Following 1H nuclear magnetic resonance spectroscopy, we generated multivariate statistical models that distinguished between the metabolic profiles of erlotinib- versus vehicle-treated mice and the integrin α1-null versus wild-type mouse genotype. Our results show the sex-dependent effects of erlotinib treatment and highlight glutamine as a metabolite that counteracts this treatment. Furthermore, we identified a set of metabolites associated with increased reactive oxygen species production, susceptibility to OA, and regulation of TRP channels in α1-null mice. Our study indicates that systemic pharmacological and genetic factors have a greater effect on serum metabolic profiles than site-specific factors such as surgery.

This paper studies the connections among the asymmetric Laplace probability density (ALPD), maximum likelihood, maximum entropy and quantile regression. We show that the maximum likelihood problem is equivalent to the solution of a maximum entropy problem where we impose moment constraints given by the joint consideration of the mean and median. The ALPD score functions lead to joint estimating equations that delivers estimates for the slope parameters together with a representative quantile. Asymptotic properties of the estimator are derived under the framework of the quasi maximum likelihood estimation. With a limited simulation experiment we evaluate the finite sample properties of our estimator. Finally, we illustrate the use of the estimator with an application to the US wage data to evaluate the effect of training on wages.

We performed neutron powder diffraction measurements on (Bi0.5Na0.5+x)TiO3and (Bi0.5+yNa0.5)TiO3to study the structural evolution induced by the non-stoichiometry. Despite the nonstoichiometry, the local structure (r≤ 3.5 Å) from the pair distribution function analysis is barely affected by a sodium deficit of up to -5 mol%. With increasing pair distance, however, the atomic pair correlations weaken due to the disorder caused by the sodium deficiency. Although the sodium and the bismuth share the same crystallographic site, their non-stoichiometries have rather opposite effects as revealed from distinctive distortions of the Bragg peaks. In addition, a Rietveld refinement demonstrates that the octahedral tilting is continually suppressed for sodium deficits up to -5 mol%. This is contrary to the effect of the bismuth deficiency, which induces little variation in the octahedral tilting.

The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b‐9. Elafin was also found to promote angiogenesis through activation of the extracellular signal‐regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling. Using a mouse orthotopic tracheal transplantation model, the authors show that cyclosporine fails to protect the microvasculature of airway transplants undergoing acute rejection, but combined therapy with cyclosporine and a neutrophil elastase inhibitor, elafin, synergistically promotes the microvascular perfusion and improves the transplant structural integrity.

Defining the molecular networks that drive breast cancer has led to therapeutic interventions and improved patient survival. However, the aggressive triple-negative breast cancer subtype (TNBC) remains recalcitrant to targeted therapies because its molecular etiology is poorly defined. In this study, we used a forward genetic screen to discover an oncogenic network driving human TNBC. SCYL1, TEX14, and PLK1 (“STP axis”) cooperatively trigger degradation of the REST tumor suppressor protein, a frequent event in human TNBC. The STP axis induces REST degradation by phosphorylating a conserved REST phospho-degron and bridging REST interaction with the ubiquitin-ligase βTRCP. Inhibition of the STP axis leads to increased REST protein levels and impairs TNBC transformation, tumor progression, and metastasis. Expression of the STP axis correlates with low REST protein levels in human TNBCs and poor clinical outcome for TNBC patients. Our findings demonstrate that the STP-REST axis is a molecular driver of human TNBC.

Abstract: BiFeO3 (BFO), Ti-doped BFO (BFTO), and Zn-doped BFO (BFZO) thin films were deposited on Pt(111)/Ti/SiO2/Si(100) substrates by using a pulsed laser deposition method. The effects of the substitution of Zn and Ti were investigated. Increased remnant polarization (P r ) and reduced coercive electric field (2E c ) were observed in the BFZO thin film capacitor. The values of 2P r and 2E c of the BFO, BFZO, and BFTO films were 100 µC/cm2 and 678 kV/cm, 107 µC/cm2 and 540 kV/cm, and 100 µC/cm2 and 720 kV/cm, respectively. The measured leakage current density of the BFZO thin film was approximately two orders of magnitude lower than that of the BFO thin film.

Abstract: We prepared (Bi0.94Eu0.06)(Fe0.94Mn0.06)O3 (BEFM), (Bi0.94Eu0.06)FeO3 (BEFO), and BiFeO3 (BFO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a pulsed laser deposition method. X-ray diffraction and Raman scattering results showed that the rhombohedral structure of the BFO film was not affected by the substitution of Eu and Mn ions. A much reduced leakage current was observed in the BEFM thin film capacitor compared to the BEFO and BFO thin film capacitors. Higher electrical breakdown field was observed in the BEFM and BEFO thin film capacitors than in the BFO thin film capacitor.

Abstract: A structure-properties relation in Bi0.5(Na1−x K x )0.5TiO3 ceramics was investigated for K contents ranging from 0 to 20 mol% substituting for Na in (Bi0.5Na0.5)TiO3 ceramics. A rhombohedral perovskite solid solution was confirmed up to x = 18 mol%. An inverse relation between depolarization temperature (T d ) and piezoelectric coefficient (d 33) was observed in the rhombohedral phase region. As x increased toward the morphotropic phase boundary (MPB), T d was lowered while d 33 was enhanced. Structurally, the rhombohedral lattice distortion (90−α) decreased while the lattice constant (a R ) increased with increasing x. 90−α appeared to be coupled with the compositiondependent variations in T d and d 33; the smaller 90 − α, the lower T d , and the higher d 33.

Abstract: (Na0.5+x K0.5−x )(Nb0.55Ta0.45)O3 (NKNT) ceramics prepared by using a solid state process were investigated for various A-site ratios between Na and K at 0 ≤ x ≤ 0.05 to determine the morphotropic phase boundary (MPB). Within the compositional range tested, X-ray diffraction patterns showed NKNT perovskite peaks with no apparent secondary peaks. Scanning electron microscope images showed little difference among microstructures composed of cube-like grains. The piezoelectric coefficient (d 33) was enhanced up to 310 pC/N at x = 0.03 from 262 pC/N at x = 0 and then decreased with further increases in x while the polymorphic phase transition (PPT) temperature (T O−T ) located around room temperature varied little with x. As a result, the increase that occurred in d 33 was mainly due to the MPB effects with the MPB composition of the NKNT ceramics at (Na0.53K0.47).

Leiomyosarcomas are malignant smooth muscle tumors that occur most commonly in the gynecologic tract and soft tissue. There are different diagnostic criteria of malignancy for smooth muscle tumors arising at gynecologic and soft tissue sites and they may be managed differently but determining the primary site of a smooth muscle tumor can be difficult in some cases. In addition, the distinction between malignant and benign gynecologic tract smooth muscle tumors on morphologic grounds can be challenging. Using a series of tissue microarrays that contain 245 cases of leiomyosarcomas (102 gynecologic) with survival data, and 49 cases of uterine leiomyoma, we examined the ability of selected immune-markers (estrogen receptor (ER) and WT1) to distinguish between leiomyosarcomas of gynecologic and nongynecologic origin. In addition, we examined whether immunostains for p16, p53 and Ki-67 could distinguish between malignant and benign gynecologic smooth muscle tumors. ER nuclear positivity was observed in 3 and 50% of the nongynecologic and gynecologic leiomyosarcomas, respectively (P<0.001). Nuclear WT1 positivity was seen in 0 and 8% of the nongynecologic and gynecologic leiomyosarcomas, respectively (P<0.001). 87% of primary gynecologic leiomyosarcomas and 2% of uterine leiomyomas showed diffuse (⩾50% of cells) p16 staining (P<0.001). 23% of gynecologic leiomyosarcomas showed p53 immunopositivity (⩾50% of cells) whereas none of the leiomyomas were positive for p53 (P<0.001). 65% of the gynecologic leiomyosarcomas and 0% of the leiomyomas exhibited >10% Ki-67 proliferation index (P<0.001). Diffuse p16 and p53 immunopositivity and high Ki-67 proliferation index, singly or in combination, yielded an overall sensitivity of 92% and specificity of 98% for distinguishing between gynecologic leiomyosarcomas and leiomyomas and can be used as indicators of malignancy for gynecologic smooth muscle tumors. Although ER positivity can be used to support the gynecologic origin of a leiomyosarcomas, nuclear WT1 immunostaining is of little use.

The degradation characteristics of InGaNbased blue laser diodes LDs are investigated at an emission wavelength of 445 nm. Two different LDs are used to determine the distinct failure characteristics with mirror reflectivities of 54 and 78. Blue LDs are operated with the same current injection during a 1000 h reliability test. Each LD gives an output power of 100 mW and 50 mW at reflectivities of 54 and 78, respectively. A slight threshold current increase is observed after 1000 h of aging at 50 mW, while the slope efficiency remains constant at its initial level before aging. At 100 mW, the slope efficiency threshold current increases 25 100 compared to values before aging. © 2009 WILEYVCH Verlag GmbH & Co. KGaA, Weinheim

Abstract: Compression ignition of homogeneous charges in internal combustion (IC) engines is expected to offer high efficiency of DI diesel engines without high levels of NOx and particulate emissions. This study is intended to find ways of extending the rich limit of HCCI operation, one of the problems yet to be overcome. Exhaust emissions characteristics are also explored through analyses of the combustion products. DME fuel, either mixed with air before induction or directly injected into the combustion chamber of a rapid compression and expansion machine, is compressed to ignite under various conditions of compression ratio, equivalence ratio, and injection timing. The characteristics of the resulting combustion and exhaust emissions are discussed in terms of the rate of heat release computed from the measured pressure, and the concentrations of THC, CO, and NOx are measured by FT-IR and CLD. The experimental data to date show that operation without knock is possible with mixtures of higher equivalence ratio when DME is directly injected rather than when it is inducted in the form of a perfectly homogeneous fuel-air mixture. Although fuel injected early in the compression stroke promotes homogeneity of the DME-air mixture in the cylinder, it causes the mixture to ignite too early to secure good thermal efficiency and knock-free operation at high loads. Low temperature reactions occur at about 660K regardless of the fueling methods, fuel injection timing and equivalence ratio. The main components of hydrocarbon emissions turned out to be unburned fuel (DME), formaldehyde and methane.

Our previous studies showed that administration of a subtoxic dose of acetaminophen (APAP) to female rats increased generation of carbon monoxide from dichloromethane, a metabolic reaction catalyzed mainly by cytochrome P450 (CYP) 2E1. In this study we examined the changes in metabolism and toxicity of APAP upon repeated administration. An intraperitoneal dose of APAP (500 mg/kg) alone did not increase aspartate aminotransferase, alanine aminotransferase, or sorbitol dehydrogenase activity in serum, but was significantly hepatotoxic when the rats had been pretreated with an identical dose of APAP 18 h earlier. The concentrations and disappearance of APAP and its metabolites in plasma were monitored for 8 h after the treatment. APAP pretreatment reduced the elevation of APAP-sulfate, but increased APAP-cysteine concentrations in plasma. APAP or APAP-glucuronide concentrations were not altered. Administration of a single dose of APAP 18 h before sacrifice increased microsomal CYP activities measured with p-nitrophenol, p-nitroanisole, and aminopyrine as probes. Expression of CYP2E1, CYP3A, and CYP1A proteins in the liver was also elevated significantly. The results suggest that administration of APAP at a subtoxic dose may result in an induction of hepatic CYP enzymes, thereby altering metabolism and toxicological consequences of various chemical substances that are substrates for the same enzyme system.

AbstractThis paper focused on the pushover analysis of a frame structure infilled with low-rise reinforced concrete (RC) wall. The softening model of concrete as well as the elastoplastic model of reinforcement was considered in the analysis associated with the equilibrium and compatibility conditions. Accordingly, the shear load-deformation relationship of the wall subjected to monotonic lateral load can be analyzed through the proposed analysis procedure. Based on the relationship obtained, we employed a single equivalent structural strut represented by a nonlinear axial member, acting in the diagonal direction of the frame, in simulating the infilled RC wall to simplify the framed wall model. As a result, the sequential pushover analysis of the whole structure could be performed easily and efficiently based on the realistic procedure proposed.To validate the proposed approach, reported results from the cyclic loading tests of fifteen specimens were adopted for the correlation. Based on the correlation, it is found that this study can provide an acceptable result of the pushover analysis and give an insight into progressive failure consequence of the framed wall structure. The proposed procedure simplifying the structural model helps the practical engineers get a higher efficiency while performing seismic evaluation and retrofit design of the high-redundancy frame structure with numerous infilled low-rise RC walls.

Polyurethane foam (PUF)/clay nanocomposites were synthesized with clay modified by polymeric 4,4′‐diphenylmethane diisocyanate (PMDI) with the application of ultrasound. Transmission electron micrographs showed that the interlayer distance increased for the polyurethane (PU)/clay nanocomposites where ultrasound was applied. The results of the transmission electron microscopy and X‐ray measurements suggest that the application of ultrasound to the clay modification with PMDI improved the efficiency of the clay modification by the effective breakup of the clay agglomerates and intercalation of the silicate layers. In the mechanical tests of the PUF/clay nanocomposites, the flexural and tensile strengths of the PUF/clay nanocomposites showed the maximum value at 3.0 wt % clay content based on PMDI. These results suggest that the increases in the flexural and tensile strengths were perhaps due to the uniform dispersion of the clay by the application of ultrasound. At the same modified clay content, the fire resistance properties were increased for the PUF/clay nanocomposites with the application of ultrasound compared to the PUF/clay nanocomposites without the application of ultrasound. The cell size and thermal conductivity were decreased for the PUF/clay nanocomposites with the application of ultrasound compared to the PUF/clay nanocomposite without the application of ultrasound. Because of these results, we suggest that the smaller cell size and lower thermal conductivity of the PUF/clay nanocomposites were mainly due to the enhanced dispersion of the clay by the application of ultrasound to the mixture of PMDI and clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3764–3773, 2006

Particle image velocimetry and smoke visualization are used to study the alteration of the flow field in the wake of a bluff body by use of an alternating current (AC) surface dielectric barrier discharge. Staggered, surface, and buried electrodes were positioned on the downstream side of circular cylinders at conditions of ReD = 1 × 104−4 × 104configured to impose a force due to the ion drift that is either along or counter to the free-stream flow direction. Smoke visualization and Particle Image Velocimetry (PIV) in the wake of the flow confirms that the configuration of the surface electrodes and operation of the discharge significantly alters the location of the flow separation point and the time-averaged velocity profiles in the near and distant wake. Measurements of the vibrational and the rotational temperature using optical emission spectroscopy on the N2second positive system (C3Πu–B3Πg) indicates that the resulting plasma is highly non-equilibrium and discounts the possibility of a thermal effect on the flow separation process. The mechanism responsible for reduction or enhancement of flow separation is attributed to the streamwise force generated by the asymmetric ion wind—the direction of which is established by the electrode geometry and the local surface charge accumulated on AC cycles.Particle image velocimetry and smoke visualization are used to study the alteration of the flow field in the wake of a bluff body by use of an alternating current (AC) surface dielectric barrier discharge. Staggered, surface, and buried electrodes were positioned on the downstream side of circular cylinders at conditions of ReD = 1 × 104−4 × 104configured to impose a force due to the ion drift that is either along or counter to the free-stream flow direction. Smoke visualization and Particle Image Velocimetry (PIV) in the wake of the flow confirms that the configuration of the surface electrodes and operation of the discharge significantly alters the location of the flow separation point and the time-averaged velocity profiles in the near and distant wake. Measurements of the vibrational and the rotational temperature using optical emission spectroscopy on the N2second positive system (C3Πu–B3Πg) indicates that the resulting plasma is highly non-equilibrium and discounts the possibility of a thermal effect on the flow separation process. The mechanism responsible for reduction or enhancement of flow separation is attributed to the streamwise force generated by the asymmetric ion wind—the direction of which is established by the electrode geometry and the local surface charge accumulated on AC cycles.

A polyurethane (PU)/clay nanocomposite was synthesized from polyol, polymeric 4,4′‐diphenyl methane diisocyanate (PMDI), and modified clay with PMDI. To achieve the modified clay with PMDI, the silanol group of the clay and the NCO group of the PMDI were reacted for 24 h at 50°C to form urethane linkage. Fourier transform IR analysis of the clay modified with the PMDI demonstrated that the NCO characteristic peak was observed in the clay after a modification reaction with PMDI. The results of the X‐ray pattern suggested that the clay layers were exfoliated from the PU/clay nanocomposite. From the results of the mechanical properties, the maximum values of the flexural and tensile strength were observed when 3 wt % clay based on PMDI was added into the PU/clay nanocomposites. The glass‐transition temperature and change in the heat capacity at glass transition temperature (ΔCp) of the PU/clay nanocomposite decreased with an increase in the modified clay content. We suggested that the decrease in the ΔCp with the modified clay content might be due to the increase of steric hindrance by the exfoliated clay layers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2879–2883, 2006

We investigated characteristics of high performance GaN-based laser diodes grown on LEO-GaN/sapphire and free-standing GaN substrates. The maximum output power was 300 mW under cw operation. The operation current and voltage were 53 mA and 4.67 V, respectively, for 30 mW-output power. Thermal simulation and junction temperature measurement of laser diodes showed that epi-down bonding was essential for the use of sapphire substrate. It was proposed that Mg diffusion into active layers was responsible for the degradation mechanism of GaN-based laser diodes. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Recent progress on the fabrication processes of blue-violet laser diodes (BV-LDs) which reduced input power and enhanced heat dissipation has been discussed. In order to reduce operating current of the BV-LDs, a novel ridge waveguide structure with two different side angles was developed, and ridge width and thickness between active layer and etched surface wais optimized, as well. For lowering of operating voltage, we optimized the thickness of the highly Mg doped p-GaN contact layer, where the ohmic metals were contacted, as well as pre-treatment process before deposition of p-electrode. Improving the fabrication processes for high power AlInGaN-based BV-LDs as well as optimizing design and growth conditions for BV-LD structures resulted in a threshold current density and a threshold voltage of 3.3 kA/cm2 and 4.4 V, respectively. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4‐diphenylmethane diisocyanate (PMDI; having functionality of 2.9), polyether polyols, silicone surfactant, amine catalysts, and distilled water. The effects of reactivity on the properties such as density, compressive and flexural strength, and glass‐transition temperature (Tg) of the PUF samples were studied. The kinetic rate of forming the PUF samples was increased with the catalyst and water content. With increasing OH value and functionality of the polyols, the density and compressive strength of the PUF samples also increased. For the PUF samples synthesized with polyols having high functionality (>5), the flexural strength of the PUF samples decreased with the functionality of the polyols. With increasing OH value and functionality of the polyols, the Tg of the PUF increased because of an increase in the degree of crosslinking of the PUF samples. The Tg value and compressive strength of the PUF samples were observed to increase with the NCO index. From this result, it was suggested that the increase in the Tg value and compressive strength of the PUF samples may be attributable to the additional crosslinks that arose from allophonate and biuret formation by the supplementary reactions of excess PMDI. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2334–2342, 2004

To investigate the effect of Sn−Ta2O5 nanostructures on lithium insertion and extraction, size-controlled Sn−Ta2O5 nanostructured electrodes, consisting of Sn nanoparticles in an amorphous, porous Ta2O5 matrix, were designed and fabricated using a cosputtering system with Sn metal and Ta2O5 targets. Transmission electron microscopy revealed well-dispersed Sn particles with average particle sizes of ~19 nm (sample A), ~30 nm (sample B), and ~50 nm (sample C). Both X-ray photoelectron spectroscopy and X-ray diffraction analysis of Sn−Ta2O5 confirmed that the Sn particles exist as a metallic crystalline structure, whereas the Ta2O5 matrix was present in an amorphous state. The performance of the Sn−Ta2O5 nanostructured electrode was superior to that of a Sn thin-film electrode during lithium insertion and extraction. The high-performance in the Sn−Ta2O5 nanostructured electrode is due to the larger number of reactive sites of Sn nanoparticles and the facilitation of the movement of lithium ions through the porous Ta2O5 matrix.

This study aimed to explore the effects of age, education and gender on the performance of eight tests in the Korean version of the CERAD neuropsychological assessment battery and to provide normative information on the tests in the Korean elderly. The battery was administered to 618 healthy volunteers aged from 60 to 90. People with serious neurological, medical and psychiatric disorders, including dementia, were excluded. Multiple linear regression analyses were performed to assess the relative contribution of the demographic factors on the score of each cognitive test. Age, education, and gender were found to have significant effects on the performance of many tests in the battery. Based on these results, 4 overlapping age normative tables (60 to 74, 65 to 79, 70 to 84, and 75 to 90 years of age) with 3 educational strata (0 to 3 years, 4 to 6 years, and 7 years and more) for both genders are presented. The normative information will be useful for a clinical interpretation of the CERAD neuropsychological battery in Korean elderly as well as for comparing the performance of the battery across countries. (JINS, 2004, 10, 72–81.)

Tracheostomy for management of neonatal airway obstruction may be life saving but is associated with complications and developmental problems. As an alternative, the effectiveness of internal mandibular distraction osteogenesis was investigated in select neonatal patients with micrognathia and upper airway obstruction. Preoperative tests (sleep study, direct laryngobronchoscopy, and “milk scan” for GI reflux) were used to select appropriate candidates for the procedure. Excluded were patients with 1) central apnea, 2) severe reflux, 3) other airway lesions, and 4) mild to moderate obstruction controlled by positioning. Of 44 newborns (aged <3 weeks) with upper airway obstruction and micrognathia seen in the neonatal intensive care unit, 19 underwent tracheostomy, 10 were discharged with home monitoring and positional instructions, and 15 underwent bilateral mandibular lengthening with microdistractors. Of those who underwent mandibular distraction, a tracheostomy was avoided in 14 of 15 patients. Relative improvement in the posterior airway space was seen on 3D CT scans, cephalograms, and laryngobronchoscopies obtained preoperatively, postoperatively, and during follow-up evaluation. One of these 15 patients required a tracheostomy for postoperative central apnea. In an average of just 4.5 days following completion of distraction, patients were discharged home with improved oral feeding and no feeding tube. This study suggests that for selected newborns, the use of internal microdistractors allows for avoidance of a tracheostomy and improved oral feeding.

Abstract.:  Fusion relations between the association schemes obtained by direct product and wreath product are established via a study of their matrix representations. The character table of the scheme obtained by the wreath product is described and some algebraic properties of the products are derived.

Electrooxidation of methanol in sulfuric acid solution was studied using Pt, Pt/Ni(1:1 and 3:1), Pt/Ru/Ni(5:4:1 and 6:3.5:0.5), and Pt/Ru(1:1) alloy nanoparticle catalysts, in relation to methanol oxidation processes in the direct oxidation methanol fuel cell. The Pt/Ni and Pt/Ru/Ni alloys showed excellent catalytic activities compared to those of pure Pt and Pt/Ru. The role of Ni as a catalytically enhancing agent in the oxidation process was interrogated using cyclic voltammetry, chronoamperometry, X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction. X-ray diffraction data showed alloy formation for all Pt/Ni, Pt/Ru/Ni, and Pt/Ru nanoparticles, whereas X-ray photoelectron spectroscopy confirmed that chemical states of Pt were exclusively metallic. The presence of metallic Ni, NiO, Ni(OH)2, NiOOH, metallic Ru, RuO2, and RuO3 was also confirmed. We found that the Pt4f binding energies for the Pt/Ni and Pt/Ru/Ni alloy nanoparticles were lower than those for clean Pt nanoparticles. The oxides that serve as the oxygen donors for the oxidation process, and the change in the electronic structure of the Pt component in the alloys versus those in Pt and Pt/Ru collectively account, we believe, for enhancement in rates of methanol oxidation. The difference in the peak shift in Pt4f between Pt/Ni and Pt/Ru alloy nanoparticles is discussed by using electronegativities of the three components:  Pt, Ru, and Ni. A comparison between the alloy nanoparticle composition and that of disk alloy electrodes under similar conditions was made in terms of the surface-to-volume ratio and surface segregation of the alloying components.

A variety of input shaper has been proposed to reduce the residual vibration of flexible structures. However, the complexity to solve the non-linear simultaneous equations increases due to addition of the constraints to improve the robustness of an input shaper. In this paper, by proposing a graphical approach which places the shaper zeros on the z -plane, the input shaper could conveniently be designed even if the constraints are added for further robustness. Furthermore, it is shown that the proposed method could be accommodated with the variations of both natural frequency and damping ratio. With a mass–damper–spring model, a better performance is obtained using the proposed new multi-hump input shaper.

To identify novel peptides that inhibit the interaction between human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 and CD4, we constructed a targeted phage-displayed peptide library in which phenylalanine and proline were fixed at the fourth and sixth positions, respectively, because Phe43 and the adjacent β-turn of CD4 are critical for interaction with gp120. Two synthetic peptides were selected after three rounds of biopanning against gp120, and one of them, G1 peptide (ARQPSFDLQCGF), exhibited specific inhibition of the interaction between gp120 and CD4 with an IC50 of about 50 μM. Structural analysis using NMR demonstrated that G1 peptide forms a compact cyclic structure similar to the CD4 region interacting with gp120. Two derivatives of G1 peptide, a linear hexameric peptide (G1-6) and a cyclic nonameric peptide (G1-c), were synthesized based on the structure of the G1 peptide. Interestingly, they showed higher inhibitory activities than did G1 peptide with IC50's of 6 and 1 μΜ, respectively. Thus, this study might provide a new insight into the development of anti-HIV-1 inhibitors.

It was reported that the area under the plasma concentration‐time curve from time zero to time infinity (AUC) of parathion was significantly smaller, and the time‐averaged total body clearance (Cl) of parathion was significantly faster after intravenous administration of parathion to rats pretreated with dexamethasone than those in control rats. This was supported by significantly faster intrinsic clearance of parathion to form paraoxon in hepatic microsomal fraction of rats pretreated with dexamethasone. The above data suggested that parathion was metabolized to paraoxon by dexamethasone‐inducible hepatic cytochrome P450 (CYP) 3A in rats. The purpose of this study is to explain the protective effects of physostigmine against paraoxon toxicity by suppressing CYP3A, and hence, decreasing formation of a toxic metabolite, paraoxon. The pharmacokinetic changes of parathion and paraoxon were investigated after intravenous administration of parathion, 3 mg/kg, to control Sprague–Dawley rats, and the rats pretreated with physostigmine (100 µg/kg, intraperitoneal injection 30 min before parathion administration). After a 1‐min intravenous infusion of parathion to rats pretreated with physostigmine, the AUC of parathion (60.4 compared with 73.7 µg min/mL) was significantly greater, Cl of parathion (49.7 compared with 40.7 mL/min/kg) was significantly slower, and amount of paraoxon recovered from liver, mesentery and large intestine at 5 min was smaller than those in control rats. Based on in vitrorat hepatic microsomal studies, physostigmine inhibited significantly the erythromycin N‐demethylase activity (1.03 compared with 0.924 nmol/mg protein/min), mainly mediated by hepatic cytochrome P450 3A in rats. The above data suggested that the formation of paraoxon was inhibited in rats pretreated with physostigmine by inhibiting CYP3A. Copyright © 2000 John Wiley & Sons, Ltd.

A data driver using the triple charge sharing method and an OP‐AMP with the low‐quiescent current have been proposed for low‐power TFT‐LCDs. The triple charge sharing method can reduce the AC power consumption of TFT‐LCDs to 1/3 of that of conventional ones. The measured quiescent current of the proposed OP‐AMP is 5 μA at VDD=5V.

The potential- and coverage-dependent infrared absorption spectroscopy (IRAS) of linearly bound CO on single-phase polycrystalline arc-melted Pt, PtRu(1/1), PtRu(8/2), PtOs(8/2), PtRuOs(8/1/1), PtRuOs(65/25/10), and Ru electrodes in 0.5 M H2SO4 are correlated with the potential-dependent X-ray photoelectron spectroscopy (XPS) of the PtRu(1/1), PtOs(8/2), and PtRuOs(65/25/10) substrates. The CO stretching frequencies decrease as the mole fraction of Pt in the alloy is decreased. The CO oxidation onset on pure Pt at 100.0% CO coverage is 0.5 V vs a reversible hydrogen electrode and shifts negatively as the alloy mole fraction of Pt is reduced. At CO dosing conditions that yield 100% coverage on pure Pt, the CO bandwidths increase with decreasing Pt mole fraction:  on pure Pt the bandwidths increase as the CO coverage is reduced. The effects of CO coverage and bulk alloy composition on the Stark tuning rates (STRs) have been systematically examined on Pt, and a series of binary and ternary alloy surfaces. The XPS data confirm a potential-dependent surface distribution of oxides and no significant surface segregation of the alloying components. The systematic displacement, to lower frequencies, of the linear STRs as the mole fraction of Pt is reduced suggests no significant island formation on the arc-melted alloy surfaces. The XPS data also suggest that the alloying metals, rather than Pt, are responsible for activation of the water required for methanol oxidation in the direct methanol fuel cell potential window.