bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Photolithography Process for Printed Circuit Board Using Liquid Crystal Mask in Place of Photomask
Authors: Oh Min Sup , Lee Jae Hong , Hong Chinsoo , Lee Ho-Nyeon , Kim Chang Kyo
Published: September 2012

In this paper, we present a photolithography method for printed circuit boards using a liquid crystal mask (LCM) in place of a photomask. The LCM photolithography method has the advantage of ease of forming various patterns. There were opaque interpixel regions of the LCMs; the areas on the dry film resist (DFR) located under the interpixel regions of the LCM were not exposed to illumination. The unexposed DFR area could be exposed to illumination by utilizing the Fresnel diffraction effects that were due to a gap maintained between the LCM and the DFR during the exposure process. DFR patterns with a width of 200 µm were obtained successfully using the 160 µm gap between LCM and DFR and three sheets of DFR for the exposure process.
Improved Organic Light Emitting Diodes Using Cryogenic LiF/Al Deposition
Authors: Chu Byung-hwan , Chin Byung Doo , Baik Kwang Hyeon , Pearton Stephen J. , Ren Fan , Jang Soohwan
Published: September 2012

The effect of cryogenic temperature deposition of Al and LiF contacts on the electrical and optical performance of organic light emitting diodes (OLEDs) was investigated. The reverse current of OLED with 77 K deposited contacts was reduced by one order of magnitude, and the output light intensity was dramatically improved compared to the device with conventional e-beam evaporated cathodes, due to the reduced damage on the metal contacts and the organic film interface. Atomic force microscope (AFM) imaging showed uniformly distributed smaller grains, and the X-ray diffraction (XRD) pattern indicated better crystallinity for the 77 K deposited metal film. Also, an abrupt interface between metal contact and polymer was observed from secondary ion mass spectroscopy (SIMS) depth profiling.
Wireless Power Transmission to Organic Light Emitting Diode Lighting Panel with Magnetically Coupled Resonator
Authors: Kim Yong-Hae , Han Jun-Han , Kang Seung-Youl , Cheon Sanghoon , Lee Myung-Lae , Ahn Seong-Deok , Zyung Taehyoung , Lee Jeong-Ik , Moon Jaehyun , Chu Hye Yong
Published: September 2012

We are successful to lit the organic light emitting diode (OLED) lighting panel through the magnetically coupled wireless power transmission technology. For the wireless power transmission, we used the operation frequency 932 kHz, specially designed double spiral type transmitter, small and thin receiver on the four layered printed circuit board, and schottky diodes for the full bridge rectifier. Our white OLED is a hybrid type, in which phosphorescent and fluorescent organics are used together to generate stable white color. The total efficiency of power transmission is around 72%.
Effects of Current Density and Frequency on Microstructure and Mechanical Properties of Ni Stencil Masks Fabricated by Pulse Electroforming
Authors: Park Geun Chul , Choi Jun Hyuk , Kim Ji Cheol , Kim Tae Woong , Song Keun , Lim Jun Hyung , Joo Jinho
Published: September 2012

We fabricated Ni stencil masks using a pulse electroforming and investigated the effects of current density and frequency on the microstructure and mechanical property. In the electroforming process, the current densities were 2.5 and 5 A/dm2 and the frequency varied from 0 (DC) to 1000 Hz at a duty cycle of 50%. Texture, microstructure, and mechanical properties varied with the current density and frequency. The preferred orientation of (220) at 2.5 A/dm2 changed to (200) as the current density increased to 5 A/dm2. Grain size decreased with decreasing current density or increasing frequency, probably due to a sufficient supply of Ni ions and the presence of inhibitor species. This decrease in grain size resulted in increase of hardness and wear resistance. However, with increase in current density and frequency (5 A/dm2 and 1000 Hz), the grain size became large, as a result of faradic current during the off-time.
Effect of Sintering Temperature on Electrical Properties of Chip on Glass Module with Direct Printing Method
Authors: Lee Young-Chul , Kim Yongil , Jung Seung-Boo
Published: September 2012

In order to apply the direct printing method to the fabrication of chip on glass (COG) modules, we examined that the effect of the sintering temperature on the electrical properties of a COG module with direct printing method. Firstly, we fabricated an Ag conductive circuit on a glass substrate by the screen-printing method. To investigate its the effect on the electrical properties of the circuit, it was sintered at various temperatures, such as 150, 200, 250, and 300 °C for 30 min. Subsequently, we conducted Au electro-plating for the fabrication of a Si dummy chip. Finally, the flip-chip bonding process was conducted using anisotropic conductive film (ACF). The printed Ag circuits were well formed on the quartz substrate without any shorts or remarkable changes compared with the initial design. The electrical properties of the printed Ag circuits improved with increasing sintering temperature. The conductive particles in the ACF were well deformed in between the Au bumps and printed Ag pads after the bonding process. The four-point probe method was employed to measure the connection resistance of the joints constructed with the Au bumps on the Si chip and printed Ag circuit on the quartz substrate. The resistances of the interconnections drastically decreased with increasing sintering temperature, i.e., subsequently converged from 11.8 Ω to 7.36 mΩ.
Schottky Barrier Height and S-Parameter of Ti, Cu, Pd, and Pt Contacts on p-Type GaN
Authors: Park Youngjun , Ahn Kwang-Soon , Kim Hyunsoo
Published: September 2012

The Schottky barrier height (SBH) of Ti, Cu, Pd, and Pt contacts on p-GaN and their work-function dependence, the S-parameter, were investigated. According to thermionic emission model, the SBH was obtained to be 0.85, 0.70, 0.61, and 0.59 eV for Ti, Cu, Pd, and Pt, respectively, yielding an S-parameter of 0.19. However, the ideality factor was as large as ∼4 and anomalous temperature dependences of the SBH and ideality factors were observed, indicating that the pure thermionic emission is not appropriate to explain carrier transport. Based on the barrier inhomogeneity and thermionic field emission models, S-parameters of 0.27 and 0.38 could be reasonably obtained.
Effect of Internal Polarization Fields in InGaN/GaN Multiple-Quantum Wells on the Efficiency of Blue Light-Emitting Diodes
Authors: Ryu Han-Youl
Published: September 2012

The author theoretically investigates the effects of internal polarization fields on the efficiency of InGaN/GaN multiple-quantum-well (MQW) blue light-emitting diodes (LEDs) based on numerical simulations. Internal quantum efficiency (IQE), current leakage, and carrier distributions are calculated with varying the strength of polarization fields to study the role of the polarization fields on the efficiency characteristics. Simulation results show that, as the strength of the polarization fields increases, electron current leakage from active layers to the p-GaN layer increases and hole concentration distribution at MQWs becomes more inhomogeneous. It is found that these two effects by the internal polarization fields lead to significant decrease in the IQE of InGaN blue LEDs.
Optical Improvement of GaN-Based Light Emitting Diodes by Interfacial Si Treatment in InGaN/GaN Quantum Well Structure
Authors: Park Sangjun , Lee Sangwon , Yoo Hongjae , Choi Joowon , Lee Sung-Nam
Published: September 2012

We investigated the optical enhancement of GaN-based light-emitting diodes (LEDs) by introducing Si treatment at the interface between the well and the barrier. The results of X-ray diffraction showed that the interfacial quality of InGaN/GaN quantum wells was slightly degraded by interfacial Si treatment. However, the intensities and full width at half-maximums (FWHMs) of photoluminescence (PL) and electroluminescence (EL) were increased by introducing interfacial Si treatment. In addition, the efficiency droop of the reference LED was 34.2% at 50 mA, while that of the Si-treated LED was 26.7% at 50 mA. Despite the increase in EL intensity, the efficiency droop was significantly decreased by interfacial Si treatment. From these results, we believe that the interfacial Si treatment will induce appropriate In localization in the InGaN active region, resulting in the improvement of optical quality of LEDs.
Effects of Cadmium Content on Optical Parameters of CdxZn1-xO Thin Films Prepared by Sol–Gel Method
Authors: Kim Min Su , Yim Kwang Gug , Leem Jae-Young
Published: September 2012

CdxZn1-xO thin films with different Cd contents ranging from 0 to 0.75 were prepared by the sol–gel spin-coating method. The optical parameters, such as optical band gap, absorption coefficient, Urbach energy, refractive index, dispersion parameter, and optical conductivity, were studied in order to investigate the effects of Cd content on the optical properties of the CdxZn1-xO thin films. The optical band gap and Urbach energy decreased as Cd content increased. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the CdxZn1-xO thin films were affected by Cd incorporation. The optical conductivity of the CdxZn1-xO thin films also increased with increasing photon energy.
Determination of the Thermoelectric Properties in Filled-Skutterudite Systems by Controlling the Process Variables
Authors: Lee Jae-Ki , Choi Soon-Mok , Seo Won-Seon , Cheong Dong-Ik , Kim Il-Ho
Published: September 2012

This study presents the optimization of the process conditions for filled-skutterudites (with a higher melting temperature and a higher aging temperature than the original skutterudites), while many studies have focused only on introducing new filler-atom compositions. For the In-filled In0.3Co4Sb12 system, the maximum value of the thermoelectric figure-of-merit, Z
T, 1.14 was obtained owing to the low thermal conductivity and high power factors. Moreover, this high Z
T value is considered to result from the optimized process variables (i.e., a higher melting temperature and a higher aging temperature than the original CoSb3). For the double-filled In0.2Yb0.1Co4Sb12 system, the maximum Z
T value of 1.26 was obtained owing to the low thermal conductivity and the high electrical conductivity. This high Z
T value was also thought to result from the optimized process variables.
Effect of Internal Electric Field in Well Layer of InGaN/GaN Multiple Quantum Well Light-Emitting Diodes on Efficiency Droop
Authors: Han Sang-Heon , Lee Dong-Yul , Lim Jin-Young , Lee Jeong Wook , Kim Dong-Joon , Kim Young Sun , Kim Sung-Tae , Park Seong-Ju
Published: September 2012

We investigate the effect of internal electric field in InGaN well layer of InGaN/GaN multiple quantum well light-emitting diodes (LEDs) on efficiency droop behavior. The simulation results show that the internal electric field in InGaN well layers of Ga-polar LEDs is same as the direction of external electric field by forward bias voltage, resulting in a strong efficiency droop. However, N-polar LEDs show that the efficiency droop is drastically improved due to an increase of internal quantum efficiency and carrier injection efficiency by weakening the internal electric field with increasing the forward bias voltage and decrease of electron overflow.
Interfacial Structure of Composites of Poly(m-xylylen adipamide) and Silica Nano-Particles
Authors: Achiwa Osamu , Kyogoku Yoshitaka , Matsuda Yasuhiro , Tasaka Shigeru
Published: September 2012

Interfacial structure of composites of poly(m-xylylen adipamide) (MXD6) and silica nano-particles (SNPs) was investigated by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and infrared (IR) spectroscopy. In the DSC curves of the composites, changes in specific heat similar to a glass transition behavior (sub-T
g) were detected at 0–40 °C, and sub-T
g decreased with the increase in the weight fraction of SNPs. Crystallization temperature (T
c) decreased, and XRD peaks became sharper with the increase in the weight fraction of SNPs. The IR spectra suggest that the hydrogen bonds between MXD6 chains were weakened by the addition of SNPs.
Improvement of Reliability Characteristics of TiO2-Based Resistive Switching Memory Device with an Inserted ZnO Layer
Authors: Liu Lifeng , Yu Di , Chen Bing , Zhang Feifei , Gao Bin , Li Boyang , Han Dedong , Kang Jinfeng , Zhang Xing
Published: September 2012

TiO2-based resistive switching memory devices with an inserted ZnO layer were fabricated, and the effect of inserting a ZnO layer between the TiO2 and bottom electrode on the reliability characteristics of TiO2-based memory devices was investigated. The improved endurance and retention performances were achieved in the TiO2-based memory device fabricated with an inserted ZnO layer. The mechanism of reliability improvement was discussed. The inserted ZnO layer is proposed to adjust the distribution of oxygen vacancies across the TiO2 layer due to the lower formation energy of oxygen vacancy in ZnO, which may be responsible for the improved reliability characteristics in the TiO2-based memory device with an inserted ZnO layer.
Tunable Middle Infrared Radiation with CdGeAs2 Crystal
Authors: Das Subhasis
Published: September 2012

Efficient continuous wave tunable mid-infrared radiation by the process of second harmonic generation of tunable CO2 laser radiation using a CdGeAs2 (CGA) crystal has been reported. Its phase matched angular tuning characteristic at the CO2 laser wavelength, phase matched angular acceptance and spectral acceptance have been measured. Considering effective figure of merit, CGA crystal has been found to be 90 times more efficient than ZnGeP2 crystal at 10.6 µm.
Low-Reset-Current Ring-Confined-Chalcogenide Phase Change Memory
Authors: Yin You , Hosaka Sumio
Published: September 2012

In this study, we proposed a ring-shaped confined chalogenide (RCC) phase change memory (PCM) cell to reduce the reset current compared with a conventional normal bottom contact (NBC) cell and a conventional normal confined chalogenide (CC) cell. The finite element analysis of the proposed RCC cell was systematically conducted depending on the radius of the center SiO2 cylinder, surrounded by the phase change material. The highest temperature at different programming currents markedly increases by increasing the radius of the SiO2 cylinder. On the basis of the simulated relationships between the cell resistance and the programming current, it was demonstrated that the derived reset current of the RCC cell can be reduced to 41% of that of the conventional NBC PCM cell.
Graphene with Electrochemical Ionic-Liquid Assistance Synthesis to Explore the Metal Adsorption Ability and the High Electrical Conductivity in Graphene/Epoxy Composite
Authors: Chang Chia-Feng , Chiang Yi-Fang , Chen Jiann-Ruey
Published: September 2012

A simple and one-step method of producing graphenes was investigated in this work. We have modified the Hummer electrolysis method and combined it with ionic liquid for productions. The results showed that the graphenes could absorb Cu2+ at 202.2 mg/g. Additionally, the mechanism of how graphenes absorb metal and the effects of acidity are described. We have proved that the synthesized graphenes successfully based on transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray powder diffraction (XRD), Raman spectroscopy (Raman), and Fourier transform infrared (FTIR) analysis. This investigation also showed that the graphenes' highest adsorption of Cu(II) at pH 8 mainly resulted from the ionic-like charge and no-defect surface. We found that the highest conductivity of 10-2 S/m was achieved as the binary graphene/epoxy composite (0.3%).
Photo Induced Negative Bias Instability of Zinc Oxide Thin-Film Transistors
Authors: Shimakawa Shin-ichi , Wang Dapeng , Furuta Mamoru
Published: September 2012

The relationship between the photo leakage current and photo induced bias stress instability of zinc oxide thin-film transistors (ZnO TFTs) was investigated. As reported in our previous work, electron traps existing near the valence band (E
V) affect the photo leakage current of ZnO TFTs. When a negative bias stress was applied under light irradiation, the tendency of the transfer curves to shift in the negative V
gs direction was consistent with the results of the photo leakage current. The electron traps existing near the E
V affected not only the photo leakage current, but also the photo induced negative bias stress instability of the ZnO TFTs.
Fourfold Increase in Quantum Efficiency in Highly Spin-Polarized Transmission-Type Photocathode
Authors: Jin Xiuguang , Ichihashi Fumiaki , Mano Atsushi , Yamamoto Naoto , Takeda Yoshikazu
Published: September 2012

We developed a new transmission-type GaAs/GaAsP strained superlattice photocathode with an AlGaAs transparent inter-layer and Si3N4 anti-reflection coating. The electrons emitted from this photocathode demonstrate a high spin-polarization of 90% with quantum efficiency as high as 0.4% that is a fourfold increase at room temperature compared with our previous photocathode.
Preservation of hepatic blood flow by direct peritoneal resuscitation improves survival and prevents hepatic inflammation following hemorrhagic shock
Authors: Hurt Ryan T. , Matheson Paul J. , Smith Jason W. , Zakaria El Rasheid , Shaheen Saad P. , McClain Craig J. , Garrison R. Neal
Published: September 2012

Conventional resuscitation (CR) from hemorrhagic shock (HS) results in gut and liver hypoperfusion, organ and cellular edema, and vital organ injury. Adjunct direct peritoneal resuscitation (DPR) with dialysate prevents gut vasoconstriction, hypoperfusion, and injury. We hypothesized that DPR might also improve hepatocellular edema, inflammation, and injury. Anesthetized male SD rats were assigned to groups ( n = 8/group): 1) sham (no HS); 2) HS (40% MAP/60 min) + intravenous fluid conventional resuscitation [CR; shed blood + 2 vol saline (SAL)/30 min]; 3) HS+CR+DPR (30 ml ip 2.5% glucose dialysate); or 4) HS+CR+SAL (30 ml ip saline). Histopathology showed lung and liver injury in HS+CR and HS+CR+SAL up to 24-h postresuscitation (post-RES) that was not in shams and which was prevented by adjunct DPR. Wet-to-dry weight ratios in HS+CR revealed organ edema formation that was prevented by adjunct DPR. HS+CR and HS+CR+SAL had 34% mortality by 24-h post-RES, which was absent with DPR (0%). Liver IFN-γ and IL-6 levels were elevated in CR compared with DPR or shams. TNF-α mRNA was upregulated in CR/sham and DPR/sham. IL-17 was downregulated in DPR/sham. CXCL10 mRNA was upregulated in CR/sham but downregulated in DPR/sham. Despite restored central hemodynamic performance after CR of HS, liver blood flow was compromised up to 24 h post-RES, and the addition of DPR restores and maintains liver perfusion at 24-h post-RES. DPR prevented liver injury, histological damage, and edema formation compared with CR alone. DPR provided a mitigating anti-inflammatory dampening of the systemic inflammatory response. In all, these effects likely account for improved survivorship in the DPR-treated group.
Influence of defunctionalization and mechanical forces on intestinal epithelial wound healing
Authors: Kovalenko Pavlo L. , Flanigan Thomas L. , Chaturvedi Lakshmi , Basson Marc D.
Published: September 2012

The influence on mucosal healing of luminal nutrient flow and the forces it creates are poorly understood. We hypothesized that altered deformation and extracellular pressure mediate, in part, the effects of defunctionalization on mucosal healing. We created patent or partially obstructing defunctionalizing jejunal Roux-en-Y anastomoses in rats to investigate mucosal healing in the absence or presence of luminal nutrient flow and measured luminal pressures to document partial obstruction. We used serosal acetic acid to induce ulcers in the proximal, distal, and defunctionalized intestinal segments. After 3 days, we assessed ulcer area, proliferation, and phosphorylated ERK. In vitro, we measured proliferation and migration in Caco-2 and IEC-6 intestinal epithelial cells subjected to cyclic strain, increased extracellular pressure, or strain and pressure together. Defunctionalization of intestine without obstruction reduced phosphorylated ERK, slowed ulcer healing, and inhibited mucosal proliferation. This outcome was blocked by PD-98059. Partial obstruction delayed ulcer healing but stimulated proliferation independently of ERK. In vitro, strain increased Caco-2 and IEC-6 proliferation and reduced migration across collagen but reduced proliferation and increased migration across fibronectin. In contrast, increased pressure and the combination of pressure and strain increased proliferation and reduced migration independently of substrate. PD-98059 reduced basal migration but increased migration under pressure. These results suggest that loss of the repetitive distension may decrease mucosal healing in defunctionalized bowel, while increased luminal pressure above anastomoses or in spastic bowel disease could further inhibit mucosal healing, despite peristaltic repetitive strain. ERK may mediate the effects of repetitive deformation but not the effects of pressure.
Bone metabolism and nutritional status during 30-day head-down-tilt bed rest
Authors: Morgan Jennifer L. L. , Zwart Sara R. , Heer Martina , Ploutz-Snyder Robert , Ericson Karen , Smith Scott M.
Published: September 2012

Bed rest studies provide an important tool for modeling physiological changes that occur during spaceflight. Markers of bone metabolism and nutritional status were evaluated in 12 subjects (8 men, 4 women; ages 25–49 yr) who participated in a 30-day −6° head-down-tilt diet-controlled bed rest study. Blood and urine samples were collected twice before, once a week during, and twice after bed rest. Data were analyzed using a mixed-effects linear regression with a priori contrasts comparing all days to the second week of the pre-bed rest acclimation period. During bed rest, all urinary markers of bone resorption increased ∼20% ( P < 0.001), and serum parathyroid hormone decreased ∼25% ( P < 0.001). Unlike longer (>60 days) bed rest studies, neither markers of oxidative damage nor iron status indexes changed over the 30 days of bed rest. Urinary oxalate excretion decreased ∼20% during bed rest ( P < 0.001) and correlated inversely with urinary calcium ( R = −0.18, P < 0.02). These data provide a broad overview of the biochemistry associated with short-duration bed rest studies and provide an impetus for using shorter studies to save time and costs wherever possible. For some effects related to bone biochemistry, short-duration bed rest will fulfill the scientific requirements to simulate spaceflight, but other effects (antioxidants/oxidative damage, iron status) do not manifest until subjects are in bed longer, in which case longer studies or other analogs may be needed. Regardless, maximizing research funding and opportunities will be critical to enable the next steps in space exploration.
Validity of hip-mounted uniaxial accelerometry with heart-rate monitoring vs. triaxial accelerometry in the assessment of free-living energy expenditure in young children: the IDEFICS Validation Study
Authors: Ojiambo Robert , Konstabel Kenn , Veidebaum Toomas , Reilly John , Verbestel Vera , Huybrechts Inge , Sioen Isabelle , Casajús José A. , Moreno Luis A. , Vicente-Rodriguez German , Bammann Karin , Tubić Bojan M. , Marild Staffan , Westerterp Klaas , Pitsiladis Yannis P.
Published: September 2012

One of the aims of Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants (IDEFICS) validation study is to validate field measures of physical activity (PA) and energy expenditure (EE) in young children. This study compared the validity of uniaxial accelerometry with heart-rate (HR) monitoring vs. triaxial accelerometry against doubly labeled water (DLW) criterion method for assessment of free-living EE in young children. Forty-nine European children (25 female, 24 male) aged 4–10 yr (mean age: 6.9 ± 1.5 yr) were assessed by uniaxial ActiTrainer with HR, uniaxial 3DNX, and triaxial 3DNX accelerometry. Total energy expenditure (TEE) was estimated using DLW over a 1-wk period. The longitudinal axis of both devices and triaxial 3DNX counts per minute (CPM) were significantly ( P < 0.05) associated with physical activity level (PAL; r = 0.51 ActiTrainer, r = 0.49 uniaxial-3DNX, and r = 0.42 triaxial Σ3DNX). Eight-six percent of the variance in TEE could be predicted by a model combining body mass (partial r2 = 71%; P < 0.05), CPM-ActiTrainer (partial r2 = 11%; P < 0.05), and difference between HR at moderate and sedentary activities (ModHR − SedHR) (partial r2 = 4%; P < 0.05). The SE of TEE estimate for ActiTrainer and 3DNX models ranged from 0.44 to 0.74 MJ/days or ∼7–11% of the average TEE. The SE of activity-induced energy expenditure (AEE) model estimates ranged from 0.38 to 0.57 MJ/day or 24–26% of the average AEE. It is concluded that the comparative validity of hip-mounted uniaxial and triaxial accelerometers for assessing PA and EE is similar.
Diaphragm efficiency estimated as power output relative to activation in chronic obstructive pulmonary disease
Authors: Finucane Kevin E. , Singh Bhajan
Published: September 2012

Muscle efficiency increases with fiber length and decreases with load. Diaphragm efficiency (Effdi) in healthy humans, measured as power output (Ẇdi) relative to the root mean square of diaphragm electromyogram (RMSdi), increases with hyperpnea due to phasic activity of abdominal muscles acting to increase diaphragm length at end expiration ( Ldi ee) and decrease inspiratory load. In chronic obstructive pulmonary disease (COPD), hyperpnea may decrease Effdiif Ldi eedecreases and load increases due to airflow obstruction and dynamic hyperinflation. To examine this hypothesis, we measured Effdiin six COPD subjects (mean forced expiratory volume in 1 s: 54% predicted) when breathing air and at intervals during progressive hypercapnic hyperpnea. Ẇdi was measured as the product of mean inspiratory transdiaphragmatic pressure (ΔPdimean), diaphragm tidal volume measured fluoroscopically, and 1/inspiratory duration. Results were compared with those of six healthy subjects reported previously. In COPD, Ldi eewas normal when breathing air. ΔPdimeanand Ẇdi increased normally, and RMSdiincreased disproportionately ( P = 0.01) with hyperpnea, and, unlike health, inspiratory capacity (IC), Ldi ee, and Effdidid not increase. IC and Ldi eewere constant with hyperpnea because mean expiratory flow increased as expiratory duration decreased ( r2= 0.65), and because expiratory flow was terminated actively by the balance between expiratory and inspiratory muscle forces near end expiration, and these forces increased proportionately with hyperpnea ( r2= 0.49). At maximum ventilation, diaphragm radius of curvature at end inspiration increased in COPD ( P = 0.04) but not controls; diaphragm radius of curvature at end inspiration and ln(Effdi) were negatively correlated ( P = 0.01). Thus in COPD with modest airflow obstruction, Effdidid not increase normally with hyperpnea due to a constant Ldi eeand inspiratory flattening of the diaphragm.
Induction of the Stem-like Cell Regulator CD44 by Rho Kinase Inhibition Contributes to the Maintenance of Colon Cancer–Initiating Cells
Authors: Ohata Hirokazu , Ishiguro Tatsuya , Aihara Yuki , Sato Ai , Sakai Hiroaki , Sekine Shigeki , Taniguchi Hirokazu , Akasu Takayuki , Fujita Shin , Nakagama Hitoshi , Okamoto Koji
Published: September 2012

The difficulty in expanding cancer-initiating cells in vitro is one of major obstacles for their biochemical characterization. We found that Rho kinase (ROCK) inhibitors as well as blebbistatin, a myosin II inhibitor, greatly facilitated the establishment of spheroids from primary colon cancer. The spheroid cells expressed cancer stem cell markers, showed the ability to differentiate, and induced tumors in mice. The spheroids were composed of cells that express various levels of CD44, whereas CD44high cells were associated with increased sphere-forming ability, expression of the activating form of β-catenin, and elevated levels of glycolytic genes, CD44−/low cells showed increased levels of differentiation markers and apoptotic cells. The spheroid cells expressed variant forms of CD44 including v6, and the induction of the variants was associated with the activating phosphorylation of c-Met. As expected from the predicted hierarchy, CD44high cells differentiated into CD44−/low cells. Unexpectedly, a fraction of CD44−/low cells generated CD44high cells, and the ROCK inhibitor or blebbistatin primed the transition by inducing CD44 expression. We propose that the transition from CD44−/low to CD44high state helps to maintain a CD44high fraction and the tumorigenic diversity in colon cancer. Cancer Res; 72(19); 5101–10. ©2012 AACR.
Microenvironmental Regulation of Epithelial–Mesenchymal Transitions in Cancer
Authors: Gao Dingcheng , Vahdat Linda T. , Wong Stephen , Chang Jenny C. , Mittal Vivek
Published: September 2012

The evolution of the cancer cell into a metastatic entity is the major cause of death in patients with cancer. Activation of the epithelial-to-mesenchymal transition (EMT) endows invasive and metastatic properties upon cancer cells that favor successful colonization of distal target organs. The observation that in many cancers distant metastases resemble the epithelial phenotype of primary tumors has led to speculation that the disseminated tumor cells recruited to the target organs undergo mesenchymal-to-epithelial transition (MET). However, the MET cascade has not been recapitulated in vivo, and the cellular and molecular regulators that promote MET remain unknown. In a recent report, using a model of spontaneous breast cancer, we have shown that bone marrow–derived myeloid progenitor cells in the premetastatic lung secrete the proteoglycan versican, which induces MET of metastatic tumor cells and accelerates metastases. This review summarizes recent progress in MET research, outlines a unique paracrine cross-talk between the microenvironment and the cancer cells, which promotes tumor outgrowth in the metastatic organ, and discusses opportunities for novel antimetastatic approaches for cancer therapy. Cancer Res; 72(19); 4883–9. ©2012 AACR.
Identification of FoxM1/Bub1b Signaling Pathway as a Required Component for Growth and Survival of Rhabdomyosarcoma
Authors: Wan Xiaolin , Yeung Choh , Kim Su Young , Dolan Joseph G. , Ngo Vu N. , Burkett Sandra , Khan Javed , Staudt Louis M. , Helman Lee J.
Published: September 2012

We identified Bub1b as an essential element for the growth and survival of rhabdomyosarcoma (RMS) cells using a bar-coded, tetracycline-inducible short hairpin RNA (shRNA) library screen. Knockdown of Bub1b resulted in suppression of tumor growth in vivo, including the regression of established tumors. The mechanism by which this occurs is via postmitotic endoreduplication checkpoint and mitotic catastrophe. Furthermore, using a chromatin immunoprecipitation assay, we found that Bub1b is a direct transcriptional target of Forkhead Box M1 (FoxM1). Suppression of FoxM1 either by shRNA or the inhibitor siomycin A resulted in reduction of Bub1b expression and inhibition of cell growth and survival. These results show the important role of the Bub1b/FoxM1 pathway in RMS and provide potential therapeutic targets. Cancer Res; 72(22); 5889–99. ©2012 AACR.
Kinesin Expression in the Central Nervous System of Humans and Transgenic hSOD1G93A Mice with Amyotrophic Lateral Sclerosis
Authors: Kuźma-Kozakiewicz Magdalena , Chudy Agnieszka , Gajewska Beata , Dziewulska Dorota , Usarek Ewa , Barańczyk-Kuźma Anna
Published: September 2012

Background: Amyotrophic lateral sclerosis is a fatal motor neuron degenerative disease. Most cases are sporadic (SALS), and approximately 10% are familial (FALS) among which over 20% are linked to the SOD1 mutation. Both SALS and FALS have been associated with retrograde axonal transport defects. Kinesins (KIFs) are motor proteins involved mainly in anterograde transport; however, some also participate in retrograde transport. Objective: The purpose of the study was to investigate and compare the expression of kinesins involved in anterograde (KIF5A, 5C) and retrograde (KIFC3/C2) axonal transport in SALS in humans and FALS in mice with the hSOD1G93A mutation. Methods: The studies were conducted on various parts of the CNS from autopsy specimens of SALS patients, and transgenic mice at presymptomatic and symptomatic stages using real-time quantitative PCR and reverse-transcription PCR. Results: All KIF expression in the motor cortex of individual SALS subjects was higher than in the adjacent sensory cortex, in contrast to the expression in control brains. It was also significantly higher in the frontal cortex of symptomatic but not presymptomatic mice compared to wild-type controls. However, the mean KIF expression in the SALS motor and sensory cortexes was lower than in control cortexes. To a lesser extent the decrease in KIF mean expression also occurred in human but not in mouse ALS spinal cords and in both human and mouse cerebella. Conclusion: Disturbances in kinesin expression in the CNS may dysregulate both anterograde and retrograde axonal transports leading to motor neuron degeneration.
Neurology and Don Quixote
Authors: Palma Jose-Alberto , Palma Fermin
Published: September 2012

Don Quixote de la Mancha, which is considered one of the most important and influential works of Western modern prose, contains many references of interest for almost all of the medical specialties. In this regard, numerous references to neurology can be found in Cervantes’ immortal work. In this study, we aimed to read Don Quixote from a neurologist’s point of view, describing the neurological phenomena scattered throughout the novel, including tremors, sleep disturbances, neuropsychiatric symptoms, dementia, epilepsy, paralysis, stroke, syncope, traumatic head injury, and headache; we relate these symptoms with depictions of those conditions in the medical literature of the time. We also review Cervantes’ sources of neurological information, including the works by renowned Spanish authors such as Juan Huarte de San Juan, Dionisio Daza Chacón and Juan Valverde de Amusco, and we hypothesize that Don Quixote’s disorder was actually a neurological condition. Although Cervantes wrote it four centuries ago, Don Quixote contains plenty of references to neurology, and many of the ideas and concepts reflected in it are still of interest.
The Antitumor Effect of GDC-0941 Alone and in Combination with Rapamycin in Breast Cancer Cells
Authors: Zheng Jie , Zou Xianjin , Yao Jia
Published: September 2012

Background: The phosphatidylinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is a key potential target in breast cancer therapy. Because some cancer cell lines are resistant to mTOR inhibition, we combined the mTOR inhibitor with the PI3K inhibitor and assayed the inhibitory effect of this combination versus that of a single inhibitor. Methods: The proliferation of MCF7, SK-BR-3, T-47D, and MDA-MB-231 cells was measured by MTT assay in the presence of GDC-0941 and/or rapamycin. Afterwards, we determined the visible changes in signaling in the PI3K/AKT/mTOR pathway by Western blotting. Results: GDC-0941 exhibited excellent inhibition on MCF7, T-47D and SK-BR-3 cells with different characteristics. In addition, GDC-0941 blocked the feedback of PI3K/Akt through S6K1, resulting in decreased Akt activity by rapamycin activation. The combination of GDC-0941 and rapamycin downregulated the key components of the cell cycle machinery, such as cyclin D1 and upregulated the apoptotic markers. Conclusion: Our findings suggest that GDC-0941, either alone or in combination with rapamycin, may serve as a new, promising approach for breast cancer treatment.
Motor Recovery Mechanisms in Patients with Middle Cerebral Artery Infarct: A Mini-Review
Authors: Jang Sung Ho
Published: September 2012

Previous studies on the mechanisms of motor recovery in patients with middle cerebral artery (MCA) infarct except for the studies on cortical peri-infarct reorganization after primary motor cortex infarct were reviewed. Eight studies were classified and reviewed by the following four motor recovery mechanisms: contribution of premotor cortex, subcortical peri-infarct reorganization, ipsilateral motor pathway, and contribution of aberrant motor pathway. MCA infarct is the most common type among the arterial territory infarcts. In addition, MCA territory is important for motor function because it comprises the corticospinal tract, the corticoreticulospinal tract and the neural tracts which are related with apraxia (superior longitudinal fasciculus and corticofugal fibers from the premotor cortex). In spite of the significance of the MCA territory for motor function, fewer studies have reported on the mechanisms of motor recovery in MCA infarct compared to total number of studies about cerebral infarct. In addition, the majority of these studies have focused on the corticospinal tract. Therefore, the total number of studies on this topic should be increased. We believe that further studies comprising other neural tracts except for the corticospinal tract including the extrapyramidal tracts such as the corticoreticulospinal and neural tracts which are related with apraxia, are necessary.
Efficacy of Auditory Training Using the Auditory Brainstem Response to Complex Sounds: Auditory Processing Disorder and Specific Language Impairment
Authors: Filippini R. , Befi-Lopes D.M. , Schochat E.
Published: September 2012

Objectives: This study verified the efficacy of a formal auditory training (AT) program in children with hearing and language disorders using the auditory brainstem response to complex sounds (c-ABR) with and without background noise. Patients and Methods: Thirty children (7–13 years) were distributed into four groups: typical development (TD: n = 7), auditory processing disorder (APD: n = 9) and specific language disorder (SLIa: n = 6, and SLIb: n = 8). All children underwent behavioral assessment of auditory processing and c-ABR with and without background noise. The APD and SLIa groups underwent 8 weeks of formal AT, but all children were reevaluated 12 weeks after the initial assessment. Results: The TD group presented better behavioral performance than the other groups. For c-ABR in silence, no significant differences were observed among groups or assessments, except regarding VA complex measures, which were altered in the APD group. For c-ABR with background noise, however, the APD, SLIa and SLIb groups presented delayed latencies. Groups that underwent formal AT improved behavioral performance and decreased latencies to c-ABR in background noise at final assessment. Conclusions: These data suggest that efficacy of formal AT can be demonstrated by c-ABR with background noise.
Main Determinants of PON1 Activity in Hemodialysis Patients
Authors: Ribeiro Sandra , do Sameiro Faria Maria , Mascarenhas-Melo Filipa , Freitas Isabel , Mendonça Maria Isabel , Nascimento Henrique , Rocha-Pereira Petronila , Miranda Vasco , Mendonça Denisa , Quintanilha Alexandre , Belo Luís , Costa Elísio , Reis Flávio , Santos-Silva Alice
Published: September 2012

Background/Aims: Cardiovascular diseases are the major cause of morbidity and mortality in hemodialysis (HD) patients. These patients present reduced paraoxonase 1 (PON1) activity that depends on genetic and non-genetic factors; however, how these factors influence PON1 activity in HD patients is poorly clarified. Our aim was to evaluate the influence of two polymorphisms and non-genetic factors on PON1 activity in HD patients. Methods: We evaluated 183 HD patients under recombinant human erythropoietin (rhEPO) treatment and 22 healthy individuals. The lipid profile [total cholesterol, triglycerides, HDL-c, LDL-c, apolipoprotein (Apo) A-I, Apo B, lipoprotein(a) and oxidized low-density lipoprotein (Ox-LDL)], inflammatory markers [adiponectin, interleukin-6 (IL-6) and C-reactive protein (CRP)], PON1 activity and PON1 gene polymorphisms (L55M and Q192R) were evaluated. Results: HD patients presented higher levels of IL-6, CRP and Ox-LDL/LDL-c, and lower PON1 activity, total cholesterol, HDL-c, LDL-c, Apo A and Apo B; the most frequent genotype was heterozygosity for L55M polymorphism and homozygosity for the Q allele, the more frequent genotype of Q192R polymorphism. Multiple regression analysis identified heterozygosity and homozygosity for L55M and Q192R polymorphisms, very low-density lipoproteins, LDL-c, Apo A and CRP levels, time on dialysis and rhEPO dose, as the independent variables significantly associated with PON1 activity. The associations with CRP, rhEPO and time on dialysis were negative. Conclusion: Our results show that the reduced PON1 activity in HD patients who are not under statin therapy is strongly associated with inflammation, longer time on dialysis and high rhEPO doses, suggesting that the reduction in PON1 activity may worsen the prognosis of these patients.
Future Directions in Family and Professional Caregiving for the Elderly
Authors: Zarit Steven H. , Reamy Allison M.
Published: September 2012

As the population ages and the expected wave of baby boomers settles into old age, there is a pressing need to examine the people and institutions that care for elders and the ways in which the system will need to adapt during the next 5-10 years to accommodate the needs of the elderly and of their caregivers. This paper examines future directions in this field, identifying the major issues from two perspectives: family caregiving and professional caregiving. Despite extensive research on caregiving, more attention to a series of methodological issues is needed, as is more extensive evaluation of promising intervention models in community and institutional settings. Effective strategies to lower caregiver distress and improve the quality of care can be implemented in efficient ways that manage costs, but the argument for innovations must be made based on efficacy.
The Diagnostic Value of Narrow-Band Imaging for the Detection of Nasopharyngeal Carcinoma
Authors: Yang Haidi , Zheng Yiqing , Chen Qiujian , Xiong Hao , Chen Bin , Zhang Zhigang , Huang Xiaoming , Peng Jieren
Published: September 2012

Objectives: To evaluate the diagnostic value of narrow-band imaging (NBI) for the detection of nasopharyngeal carcinoma (NPC). Study Design: Prospective study. Setting: Tertiary medical center. Subjects and Methods: Between December 2009 and June 2010, a total of 1,854 patients were examined by means of an electronic nasopharyngolaryngoscope equipped with conventional white light (WL) and an NBI system. The sensitivity, specificity and positive/negative predictive values for detecting NPC were calculated and compared. Results: Of these patients, 62 cases (3.34%) were pathologically confirmed as NPC. The sensitivity, specificity, positive predictive value and negative predictive value for detecting NPC significantly increased from 90.3, 75.4, 11.3 and 99.6% with WL up to 100, 99.2, 81.6 and 100% with NBI, respectively. Conclusion: Our findings suggested that NBI endoscopy might serve as an ideal tool in the detection of NPC.
Clinical Application of Subjective Measurements for OSAS Assessment: Predictive Factors of Syndrome Severity
Authors: Proimos Efklidis , Kiagiadaki Devora , Kaprana Antigoni , Chimona Theognosia S. , Maroudias Nicolas J. , Papadakis Chariton E.
Published: September 2012

Purpose of the Study: To examine the clinical value of subjective evaluations of obstructive sleep apnea syndrome (OSAS) in correlation with syndrome severity as diagnosed with polysomnography. Procedures: 210 patients with mild to severe OSAS were assessed. Objective evaluation included polysomnography. Subjective assessment included full ENT examination, neck circumference (NC) plus body mass index measurements, Mueller maneuver and Epworth Symptom Scale (ESS). Results: The presence of lateral pharyngeal wall movement, abnormal ESS scoring and male gender can be considered independent risk factors for the prediction of moderate/severe OSAS (p < 0.05). Increased NC can also be considered a clinical risk factor related to male gender and lateral pharyngeal wall movement (p = 0.05). Conclusions: Subjective OSAS assessment, including evaluation of lateral pharyngeal wall movement, ESS scoring and NC measurement can safely predict, mainly in males, OSAS severity, as diagnosed with polysomnography. Message of the Paper: Subjective assessment from the ENT point of view should raise high suspicion towards the early diagnosis of moderate/severe OSAS.
Alzheimer’s Disease with Vascular Component: A Distinct Clinical Entity
Authors: Olazarán Javier , Navarro Eloísa , Rojo José Manuel
Published: September 2012

Background: Longitudinal reports on the clinical features of patients with Alzheimer’s disease (AD) and concomitant cerebrovascular disease are scarce. Methods: We elaborated a working definition of AD with vascular component (ADVC), and this definition was retrospectively investigated in a cohort of patients with cognitive deterioration who were prescribed a cholinesterase inhibitor during usual practice. Results: A total of 137 patients with probable AD and 66 patients with ADVC were studied during a mean follow-up period of 2.8 years. Univariate analyses demonstrated worse functional evolution and anticipation of psychotic symptoms and agitation in the ADVC group. Conclusions: The present results are consistent with an additive model of predominantly frontal-subcortical vascular damage in AD.
Biocompatible Peritoneal Dialysis Solution Preserves Residual Renal Function
Authors: Kim Sejoong , Oh Kook-Hwan , Oh Jieun , Kim Soo Jin , Chung Wookyung , Song Young Rim , Na Ki Young , Oh Yun Kyu , Ahn Curie , Kim Sung Gyun , Tan Kathryn C.B.
Published: September 2012

Background/Aims: The long-term effects of biocompatible peritoneal dialysis (PD) solution on residual renal function (RRF), inflammation, adipokines and metabolic acidosis are controversial. We evaluated the effects of biocompatible PD solution in continuous ambulatory PD (CAPD) patients for an additional 12-month period. Method: Among 91 incident patients who started CAPD with either biocompatible PD solution (Balance®, Fresenius; LS, n = 48) or conventional PD solution (CAPD/DPCA®, Fresenius; CS, n = 43), 63 patients, who were followed for 12 months, were enrolled and followed for an additional 12 months. Results: After 24 months of treatment, the glomerular filtration rate (GFR) of the LS group was twofold higher compared to the CS group (33.5 ± 30.7 vs. 16.3 ± 17.9 l/week/1.73 m2, respectively, p = 0.021). In a subgroup of patients with an initial GFR >2 ml/min/1.73 m2, the GFR of the LS group was significantly higher than the rate of the CS group after 24 months (43.7 ± 30.5 vs. 18.6 ± 19.0 l/week/1.73 m2, respectively, p = 0.042). Over a 24-month period, effluent cancer antigen-125 levels were significantly increased in the LS group compared to the CS group, while effluent interleukin-6 levels did not differ between the two groups. The serum tCO2 levels were consistently higher in the LS group compared to the CS group. Conclusions: We found that the effect of LS on preserving RRF may be maintained over a 24-month treatment period in CAPD patients, and LS use may have other benefits, such as the correction of metabolic acidosis.