bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cell culture medium components on color of formulated monoclonal antibody drug substance
Authors: Vijayasankaran Natarajan , Varma Sharat , Yang Yi , Mun Melissa , Arevalo Silvana , Gawlitzek Martin , Swartz Trevor , Lim Amy , Li Feng , Zhang Boyan , Meier Steve , Kiss Robert
Published: June 2013

As the industry moves toward subcutaneous delivery as a preferred route of drug administration, high drug substance concentrations are becoming the norm for monoclonal antibodies. At such high concentrations, the drug substance may display a more intense color than at the historically lower concentrations. The effect of process conditions and/or changes on color is more readily observed in the higher color, high concentration formulations. Since color is a product quality attribute that needs to be controlled, it is useful to study the impact of process conditions and/or modifications on color. This manuscript summarizes cell culture experiments and reports on findings regarding the effect of various media components that contribute to drug substance color for a specific monoclonal antibody. In this work, lower drug substance color was achieved via optimization of the cell culture medium. Specifically, lowering the concentrations of B‐vitamins in the cell culture medium has the effect of reducing color intensity by as much as 25%. In addition, decreasing concentration of iron was also directly correlated color intensity decrease of as much as 37%. It was also shown that the color of the drug substance directly correlates with increased acidic variants, especially when increased iron levels cause increased color. Potential mechanisms that could lead to antibody coloration are briefly discussed. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1270–1277, 2013
Initial evaluation of protein throughput and yield characteristics on nylon 6 capillary‐channeled polymer (C‐CP) fiber stationary phases by frontal analysis
Authors: Randunu K. Manoj , Marcus R. Kenneth
Published: June 2013

Nylon 6 capillary‐channeled polymer (C‐CP) fibers are investigated as an alternative support/stationary phase for downstream processing of macromolecules. Ionizable amine and carboxylic acid end groups on the native fiber surface allow for ion exchange chromatography (IEC). The low cost and ability to operate at high linear velocities and low back pressures are practical advantages of C‐CP fibers for preparative‐scale macromolecule separations. The lack of fiber porosity ensures facile adsorption/desorption that is conducive to high throughput and recoveries/yields. Described here is a preliminary investigation of the processing characteristics of lysozyme on nylon 6 fibers with an eye toward downstream processing applications. Fibers were packed into microbore (0.8 mm i.d.) and analytical‐size (2.1 mm i.d.) columns for the evaluation of the role of linear velocity on pressure drop, frontal throughput, and yield. Protein isolation by frontal development involved three steps: loading of the column to breakthrough, an aqueous wash, and a salt wash to recover the protein. Frontal throughput was evaluated with different salt concentrations (0–1000 mM NaCl) and different linear velocities (6–24 mm s−1). The observed throughput values are in the range of 0.12–0.20 mg min−1 when 0.25 mg mL−1 lysozyme (in 20 mM Tris‐HCl) is loaded onto 78 mg of C‐CP fiber in 0.52 mL volume analytical columns. Increased throughput and yield were found when protein was loaded and eluted at high linear velocity. Results of this study lend credence to the further development of C‐CP fibers for biomacromolecule processing on larger scales. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1222–1229, 2013
Stenting of a left main coronary artery compressed by a dilated main pulmonary artery
Authors: Chaikriangkrai Kongkiat , Polsani Venkateshwar , Wei Liu , Kleiman Neal , Chang Su Min
Published: June 2013

Left main coronary artery (LMCA) disease caused by external compression by a dilated main pulmonary artery (MPA) is an uncommon clinical entity but is one of the reversible causes of chest pain in patients with pulmonary hypertension. Traditionally, treatment of LMCA disease involves coronary artery bypass graft surgery. However, for LMCA compression by a dilated MPA, coronary angioplasty with stenting has recently been reported to have good outcomes and might be more suitable in some patients with high risk associated with surgery. Herein, we describe a 54‐year‐old man with pulmonary arterial hypertension and external compression of the LMCA by the dilated main pulmonary artery that was treated with angiographic and intravascular ultrasound‐guided coronary angioplasty and stenting. Also we briefly review current literatures about LMCA compression by a dilated MPA. © 2013 Wiley Periodicals, Inc.
A tumorigenic actin mutant alters fibroblast morphology and multicellular assembly properties
Authors: Blache Ulrich , Silván Unai , Plodinec Marija , Suetterlin Rosmarie , Jakob Roman , Klebba Ina , Bentires‐Alj Mohamed , Aebi Ueli , Schoenenberger Cora‐Ann
Published: June 2013

Tumor initiation and progression are accompanied by complex changes in the cytoarchitecture that at the cellular level involve remodeling of the cytoskeleton. We report on the impact of a mutant β‐actin (G245D‐actin) on cell structure and multicellular assembly properties. To appreciate the effects of the Gly245Asp substitution on the organization of the actin cytoskeleton, we examined the polymerization properties of G245D‐actin in vitro by pyrene polymerization assays and total internal reflection fluorescence microscopy (TIRF). The mutant actin on its own has a significantly reduced polymerization efficiency compared to native actin but also modifies the polymerization of actin in copolymerization experiments. Comparison of the structure of Rat‐2 fibroblasts and a stably transfected derivate called Rat‐2‐sm9 revealed the effects of G245D‐actin in a cellular environment. The overall actin levels in Rat‐2‐sm9 show a 1.6‐fold increase with similar amounts of mutant and wild‐type actin. G245D‐actin expression renders Rat‐2‐sm9 cells highly tumorigenic in nude mice. In Rat‐2‐sm9 monolayers, G245D‐actin triggers the formation of extensive membrane ruffles, which is a characteristic feature of many transformed cells. To approximate complex cell–cell and cell‐matrix interactions that occur in tumors and might modulate the effects of G245D‐actin, we extended our studies to scaffold‐free 3D spheroid cultures. Bright field and scanning electron microscopy (SEM) show that Rat‐2‐sm9 and Rat‐2 cells share essential features of spheroid formation and compaction. However, the resulting spheroids exhibit distinct phenotypes that differ mainly in surface structure and size. The systematic comparison of transformed and normal spheroids by SEM provides new insights into scaffold‐free fibroblast spheroid formation. © 2013 Wiley Periodicals, Inc.
Textural versus electrostatic exclusion‐enrichment effects in the effective chemical transport within the cortical bone: A numerical investigation
Authors: Lemaire T. , Kaiser J. , Naili S. , Sansalone V.
Published: June 2013

Interstitial fluid within bone tissue is known to govern the remodelling signals’ expression. Bone fluid flow is generated by skeleton deformation during the daily activities. Due to the presence of charged surfaces in the bone porous matrix, the electrochemical phenomena occurring in the vicinity of mechanosensitive bone cells, the osteocytes, are key elements in the cellular communication. In this study, a multiscale model of interstitial fluid transport within bone tissues is proposed. Based on an asymptotic homogenization method, our modelling takes into account the physicochemical properties of bone tissue. Thanks to this multiphysical approach, the transport of nutrients and waste between the blood vessels and the bone cells can be quantified to better understand the mechanotransduction of bone remodelling. In particular, it is shown that the electrochemical tortuosity may have stronger implications in the mass transport within the bone than the purely morphological one.Copyright © 2013 John Wiley & Sons, Ltd.
Pharmacokinetics and comparative bioavailability of domperidone suspension and tablet formulations in healthy adult subjects
Authors: Helmy Sally A. , El Bedaiwy Heba M.
Published: June 2013

Domperidone is a dopamine antagonist with a unique gastroprokinetic and antiemetic properties. This study was conducted to evaluate the pharmacokinetics (PKs) and comparative bioavailability of suspension (reference) and tablet (test) formulations of domperidone. In vivo study was established according to a single‐center, randomized, single‐dose, laboratory‐blinded, two way, cross‐over study with a washout period of 1 week. Under fasting conditions, 26 healthy Egyptian male volunteers were randomly allocated to receive a single oral dose of either 20 mL domperidone or two tablets (each contains 10 mg domperidone) of marketed suspension and tablet formulations. Plasma samples were obtained over a 24‐hour interval and analyzed for domperidone by reversed phase liquid chromatography with fluorescence detection. The 90% confidence intervals for the ratio of log transformed values of Cmax, AUC0–t, and AUCt–∞ of the two treatments were within the acceptable range (0.8–1.25) for bioequivalence. From PK perspectives, in this small study in healthy Egyptian adult male volunteers, a single 20 mg dose of the tablet formulation was bioequivalent to a single 20 mg dose of the suspension formulation based on the US FDA's regulatory definition. No adverse events occurred or were reported during the study and both formulations were well tolerated.
The role of pre‐event canopy storage in throughfall and stemflow by using isotopic tracers
Authors: Allen S. T. , Brooks J. R. , Keim R. F. , Bond B. J. , McDonnell J. J.
Published: June 2013

Stable isotopes can be a valuable tool for tracing the redistribution, storage, and evaporation of water associated with canopy interception of rainfall. Isotopic differences between throughfall and rainfall have been attributed to three mechanisms: evaporative fractionation, isotopic exchange with ambient vapor, and temporal redistribution. We demonstrate the potential importance of a fourth mechanism: rainfall mixing with water retained within the canopy (in bark, epiphytes, etc.) from prior rain events. Amount and isotopic composition (18O and 2H) of rainfall and throughfall were measured over a 3‐month period in a Douglas‐fir forest in the Cascade Range of Oregon, USA. The range of spatial variability of throughfall isotopic composition exceeded the differences between event‐mean isotopic compositions of rainfall and throughfall. Inter‐event isotopic variation of precipitation was high and correlated with the isotopic deviation of throughfall from rainfall, likely related to a high canopy/bark storage capacity storage bridging events. Both spatial variability of throughfall isotopic composition and throughfall–precipitation isotopic differences appear to have been controlled by the temporally varying influence of residual precipitation from previous events. Therefore, isotopic heterogeneity could indicate local storage characteristics and the partitioning of flow‐paths within the canopy. Copyright © 2013 John Wiley & Sons, Ltd.
Fire hazard assessment for a green railway station
Authors: Chow W. K. , Qu L.
Published: June 2013

A green railway station adopting natural ventilation was built in Hong Kong to promote sustainable architectural design. Similar to many other green or sustainable projects, such design failed to comply with the local fire safety codes. There are potential fire hazards due to the adopted green features. Better ventilation provision would supply more air to burn the combustibles in case of fire. Performance‐based design was applied using the timeline analysis to determine the fire safety provisions. In this paper, fire simulations were carried out to predict the available safe egress time (ASET) under low design fires with smoke toxicity including only the carbon monoxide concentration. Evacuation simulations were conducted to predict the required safe egress time (RSET) under low passenger loadings. Studies on human behaviour under big fires and heavy passenger loadings were not included. Problems to be encountered in this green railway station using the timeline analysis will be pointed out in this paper. ASET was estimated by computational fluid dynamics with bigger fires resulted from the green features. RSET was estimated by evacuation software under local passenger loadings. The results indicated that ASET are less than RSET under big fires with heavy passenger loadings. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of Composition Ratio of Ni‐YSZ Anode on Distribution of Effective Three‐Phase Boundary and Power Generation Performance
Authors: Kishimoto M. , Miyawaki K. , Iwai H. , Saito M. , Yoshida H.
Published: June 2013

Ni‐YSZ anode of solid oxide fuel cells (SOFCs) with three different compositions are examined and compared through electrochemical measurement, microstructural analysis, and numerical simulation. Three‐dimensional (3D) microstructure of the porous anodes is directly observed using focused ion beam and scanning electron microscope (FIB‐SEM), and microstructural parameters such as phase connectivity and three‐phase boundary (TPB) density are quantified to correlate the microstructure to the performance. 3D numerical simulation using the obtained microstructure is conducted considering the various transport phenomena and the electrochemical reaction in the anodes to predict their overall electrochemical performance. The performance of the Ni:YSZ = 30:70 anode is measured significantly lower than those of the Ni:YSZ = 50:50 and 70:30 anodes, which is attributed to the elongation of the ionic transport pathways. The poor connectivity of the Ni phase in the Ni:YSZ = 30:70 anode shifts the electrochemically active region far from the anode–electrolyte interface, resulting in higher Ohmic loss. The amount and distribution of the effective TPB associated with the phase connectivity are essentially important to explain the anode performance. The 3D numerical simulation qualitatively reproduces the anode performance and gives detailed information about the internal states of the anodes such as the distribution of the charge‐transfer current.
Dempster-Shafer theory applied to regulatory decision process for selecting safer alternatives to toxic chemicals in consumer products
Authors: Park Sung Jin , Ogunseitan Oladele A , Lejano Raul P
Published: June 2013

Regulatory agencies often face a dilemma when regulating chemicals in consumer products—namely, that of making decisions in the face of multiple, and sometimes conflicting, lines of evidence. We present an integrative approach for dealing with uncertainty and multiple pieces of evidence in toxics regulation. The integrative risk analytic framework is grounded in the Dempster–Shafer (D–S) theory that allows the analyst to combine multiple pieces of evidence and judgments from independent sources of information. We apply the integrative approach to the comparative risk assessment of bisphenol-A (BPA)-based polycarbonate and the functionally equivalent alternative, Eastman Tritan copolyester (ETC). Our results show that according to cumulative empirical evidence, the estimated probability of toxicity of BPA is 0.034, whereas the toxicity probability for ETC is 0.097. However, when we combine extant evidence with strength of confidence in the source (or expert judgment), we are guided by a richer interval measure, (Bel(t), Pl(t)). With the D–S derived measure, we arrive at various intervals for BPA, with the low-range estimate at (0.034, 0.250), and (0.097,0.688) for ETC. These new measures allow a reasonable basis for comparison and a justifiable procedure for decision making that takes advantage of multiple sources of evidence. Through the application of D–S theory to toxicity risk assessment, we show how a multiplicity of scientific evidence can be converted into a unified risk estimate, and how this information can be effectively used for comparative assessments to select potentially less toxic alternative chemicals. Integr Environ Assess Manag 2014;10:12–21. © 2013 SETAC
Cerebellar hemorrhage in very low birth weight premature infants: The advantage of the posterolateral fontanelle view
Authors: Soudack Michalle , Jacobson Jeffrey , Raviv‐Zilka Lisa , Ben‐Shlush Aviva , Kuint Jacob
Published: June 2013

Objective

The purpose of this study was to determine the prevalence of cerebellar hemorrhage in very low birth weight infants using the posterolateral fontanelle for ultrasound (US) examination.

Methods

The study included 125 very low birth weight premature infants (defined as equal or less than 1500 grams at birth) hospitalized in the premature or neonatal intensive care departments that had at least one head US examination including both anterior and posterolateral fontanelle scans.

Results

On US performed through the posterolateral fontanelle, four (3.2%) infants had echogenic posterior fossa lesions interpreted as hemorrhages. None of these lesions were initially or retrospectively observed through the standard anterior fontanelle scan. Two infants died at age 4 and 39 days, respectively. All survivors are being followed up in the hospital's neurodevelopment outpatient clinic.

Conclusions

Cerebellar hemorrhage may be overlooked on standard anterior fontanelle views. The posterolateral approach may assist in diagnosing these lesions. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 41:395–401, 2013
Lunar tidal winds between 80 and 110 km from UARS/HRDI wind measurements
Authors: Zhang Jesse T. , Forbes Jeffrey M.
Published: June 2013

Recent observations and models show the considerable effects of upward‐propagating lunar atmospheric tides on many aspects of the ionosphere‐thermosphere system. A key aspect of atmosphere‐ionosphere coupling is the wind field in the ionospheric E region (circa 100–150 km), where the dynamo generation of electric fields occurs. Yet, global specifications of lunar tidal winds exist only in theoretical predictions although years of satellite observations on atmospheric winds exist with almost global coverage. In the present paper, we report on quasi‐global semidiurnal lunar tidal winds up to 115 km from data gathered by the High Resolution Doppler Imager (HRDI) on board the Upper Atmosphere Research Satellite during the early years from 1991 to 1999. The observed lunar semidiurnal tidal winds are consistent with global scale wave model (GSWM) simulations in both amplitude and phase, with maximum amplitudes located between about ±40°N–60°N around the solstices. The peak amplitudes of the lunar tidal winds lie in the 10–15 ms−1range, whereas those simulated by GSWM lie between 15 and 25 ms−1. The smaller HRDI amplitudes are likely due in part to amplitude suppression in construction of the climatological mean resulting from year‐to‐year phase variability in the lunar tide. It is also possible that wave dissipation is underestimated to some degree in the GSWM.
Less morbidity after introduction of a new departmental policy for patients who undergo open distal pancreatectomy
Authors: Yui Rintaro , Satoi Sohei , Toyokawa Hideyoshi , Yanagimoto Hiroaki , Yamamoto Tomohisa , Hirooka Satoshi , Yamaki So , Ryota Hironori , Michiura Taku , Inoue Kentaro , Matsui Yoichi , Kwon A‐Hon
Published: June 2013

Background

The aim of this study was to retrospectively compare morbidity and mortality before and after introduction of a new departmental policy for patients who undergo distal pancreatectomy.

Methods

We have introduced the use of an ultrasonically‐activated device in distal pancreatectomy, an “early removal of drains” policy and perioperative management using a clinical pathway since May 2006. Group A consisted of 52 consecutive patients from 2000 to February 2006. Group B consisted of 57 consecutive patients from May 2006 to 2010.

Results

Although there was no difference in the fluid collection rate within 30 postoperative days (Group A, 44% vs. Group B, 35%), the rates of intra‐abdominal abscess (A, 19% vs. B, 4%) and grade 3/4 of the Clavien classification (A, 23% vs. B, 9%) in Group B were significantly lower than in Group A (P < 0.05). Time of drain removal (median 3 days vs. 8 days) and length of in‐hospital stay (median 8 days vs. 17 days) in Group B were significantly shorter than in Group A (P < 0.001).

Conclusion

The implementation of new departmental guidelines for distal pancreatectomy was closely associated with a low frequency of intra‐abdominal abscess and grade 3/4 Clavien score, resulting in a shorter in‐hospital stay.
Through the eye of an electrospray needle: mass spectrometric identification of the major peptides and proteins in the milk of the one‐humped camel (Camelus dromedarius)
Authors: Alhaider Abdulqader , Abdelgader Abdel Galil , Turjoman Abdullah Arif , Newell Keri , Hunsucker Stephen W. , Shan Baozhen , Ma Bin , Gibson David S. , Duncan Mark W.
Published: June 2013

The milk of the one‐humped camel (Camelus dromedarius) reportedly offers medicinal benefits, perhaps because of its unique bioactive components. Milk proteins were determined by (1) two‐dimensional gel electrophoresis and peptide mass mapping and (2) liquid chromatography–tandem mass spectrometry (LC–MS/MS) following one‐dimensional polyacrylamide gel electrophoresis. Over 200 proteins were identified: some known camel proteins including heavy‐chain immunoglobulins and others exhibiting regions of exact homology with proteins from other species. Indigenous peptides were also identified following isolation and concentration by two strategies: (1) gel‐eluted liquid fraction entrapment electrophoresis and (2) small‐scale electrophoretic separation. Extracts were analyzed by LC–MS/MS and peptides identified by matching strategies, by de novo sequencing and by applying a sequence tag tool requiring similarity to the proposed sequence, but not an exact match. A plethora of protein cleavage products including some novel peptides were characterized. These studies demonstrate that camel milk is a rich source of peptides, some of which may serve as nutraceuticals. Copyright © 2013 John Wiley & Sons, Ltd.
The influence of stem design on critical squeaking friction with ceramic bearings
Authors: Fan Na , Morlock Michael M. , Bishop Nicholas E. , Huber Gerd , Hoffmann Norbert , Ciavarella Michele , Chen Guang X. , Hothan Arne , Witt Florian
Published: June 2013

Ceramic‐on‐ceramic hip joints have been reported to squeak, a phenomenon that may occur in compromised lubrication conditions. One factor related to the incidence of in vivo squeaking is the stem design. However, it has not yet been possible to relate stem design to squeaking in deteriorating lubrication conditions. The purpose of this study was to determine critical friction factors for different stem designs. A hip simulator was used to measure the friction factor of a ceramic bearing with different stem designs and gradually deteriorating lubrication represented by evaporation of a volatile fluid lubricant. The critical squeaking friction factor was measured at the onset of squeaking for each stem. Critical friction was higher for the long cobalt chrome (0.32 ± 0.02) and short titanium stems (0.39 ± 0.02) in comparison with a long titanium stem (0.29 ± 0.02). The onset of squeaking occurred at a friction factor lower than that measured for dry conditions, in which squeaking is usually investigated experimentally. The results suggest that shorter or heavier stems might limit the possibility of squeaking as lubrication deteriorates. The method developed can be used to investigate the influence of design parameters on squeaking probability. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1627–1632, 2013
Metaphyseal fracture healing in a sheep model of low turnover osteoporosis induced by hypothalamic–pituitary disconnection (HPD)
Authors: Bindl Ronny , Oheim Ralf , Pogoda Pia , Beil Frank Timo , Gruchenberg Katharina , Reitmaier Sandra , Wehner Tim , Calcia Enrico , Radermacher Peter , Claes Lutz , Amling Michael , Ignatius Anita
Published: June 2013

We recently established a large animal model of osteoporosis in sheep using hypothalamic–pituitary disconnection (HPD). As central regulation is important for bone metabolism, HPD‐sheep develop severe osteoporosis because of low bone turnover. In this study we investigated metaphyseal fracture healing in HPD‐sheep. To elucidate potential pathomechanisms, we included a treatment group receiving thyroxine T4 and 17β‐estradiol. Because clinically osteoporotic fractures often occur in the bone metaphysis, HPD‐sheep and healthy controls received an osteotomy in the distal femoral condyle. Half of the HPD‐sheep were systemically treated with thyroxine T4 and 17β‐estradiol during the healing period. Fracture healing was evaluated after 8 weeks using pQCT, µCT, and histomorphometrical analysis. Bone mineral density (BMD) and bone volume/total volume (BV/TV) were considerably reduced by 30% and 36%, respectively, in the osteotomy gap of the HPD‐sheep compared to healthy sheep. Histomorphometry also revealed a decreased amount of newly formed bone (−29%) and some remaining cartilage in the HPD‐group, suggesting that HPD disturbed fracture healing. Thyroxine T4 and 17β‐estradiol substitution considerably improved bone healing in the HPD‐sheep. Our results indicate that fracture healing requires central regulation and that thyroxine T4 and 17β‐estradiol contribute to the complex pathomechanisms of delayed metaphyseal bone healing in HPD‐sheep. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1851–1857, 2013
A finite element method for heat transfer of power‐law flow in channels with a transverse magnetic field
Authors: Shi Huandi , Lin Ping , Li Botong , Zheng Liancun
Published: June 2013

Heat transfer of a power‐law non‐Newtonian incompressible fluid in channels with porous walls has not been carefully studied using a proper numerical method despite a few constructions of approximate analytic solutions through the similarity transformation and perturbation method for Newtonian fluids (i.e. power‐law index being one). In this paper, we propose a finite element method for the thermal incompressible flow equations. The incompressible condition is treated by a penalty formulation. Numerical solutions are validated by comparing them with an approximate analytic solution of the Navier–Stokes equation in the Newtonian fluid case. Then, the method is used to simulate the heat transfer of various power‐law fluids. Additionally, unlike previous studies, we allow the thermal diffusivity to be a function of temperature gradient. The effect of different values of the parameters on the temperature and velocity is also discussed in this paper. Copyright © 2013 John Wiley & Sons, Ltd.
Spike patterns in a reaction–diffusion ODE model with Turing instability
Authors: Härting Steffen , Marciniak‐Czochra Anna
Published: June 2013

We explore a mechanism of pattern formation arising in processes described by a system of a single reaction–diffusion equation coupled with ordinary differential equations. Such systems of equations arise from the modeling of interactions between cellular processes and diffusing growth factors. We focus on the model of early carcinogenesis proposed by Marciniak‐Czochra and Kimmel, which is an example of a wider class of pattern formation models with an autocatalytic non‐diffusing component. We present a numerical study showing emergence of periodic and irregular spike patterns because of diffusion‐driven instability. To control the accuracy of simulations, we develop a numerical code on the basis of the finite‐element method and adaptive mesh grid. Simulations, supplemented by numerical analysis, indicate a novel pattern formation phenomenon on the basis of the emergence of nonstationary structures tending asymptotically to a sum of Dirac deltas. Copyright © 2013 John Wiley & Sons, Ltd.
Design of a Compact Planar Antenna for UWB Systems
Authors: Guo Lu , Chen Xiaodong
Published: June 2013

A novel compact antenna design for ultra‐wideband systems is presented. The proposed miniature antenna is achieved by combining three miniaturization techniques. The optimal design of this type of antenna can provide an ultrawide 10‐dB impedance bandwidth with reasonable radiation properties. It also features a very small dimension, 12 × 23 mm2 in physical size and 0.24 λ (at 3.1 GHz) in electrical size, respectively. The key parameters that affect the performance of the antenna are investigated. Good agreement is obtained between the simulated and the measured antenna characteristics. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1989–1992, 2013
High Bandwidth Silicon Millimeter Waveguides
Authors: Wang Qidong , Guidotti Daniel , Cao Liqiang , Cui Jie , Wan Lixi , Ye Tianchun
Published: June 2013

Interchip communication on a multichip module or silicon interposer continues to rely on copper transmission lines. While very short reach optical communication is expected to provide advantage in bandwidth density, millimeter data transmission may offer additional options in phase and amplitude modulation leading to higher data rates per channel. In this communication, we consider the fabrication options for silicon filled rectangular waveguide and investigate their frequency dispersion by simulating the waveguide channel and obtaining the S‐parameters. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1996–1999, 2013
Triple‐Band Cpw‐Fed Planar Monopole Antenna for Wlan/Wimax Application
Authors: Iddi Hashim U. , Kamarudin Muhammad R. , Rahman Tharek A. , Abdulrahman Abdulrahman Y. , Khalily Mohsen , Jamlos M. F.
Published: June 2013

A triple‐band planar monopole antenna is presented in this article. The antenna consists of three strips which correspond to operating frequency bands of 2.4, 3.5, and 5.8 GHz. The proposed antenna has been designed, simulated, and fabricated on 20 × 38 mm2 FR4 board. There is good agreement between simulation and measurement results in terms of return loss and radiation pattern. The proposed antenna provides measured −10 dB bandwidths of 200 MHz for the 2.4 GHz (from 2.36 to 2.56 GHz); 620 MHz for the 3.5 GHz (from 3.48 to 4.10 GHz); and 1.38 GHz for 5.8 GHz (from 5.65 to 7.03 GHz). Moreover, the antenna provides the measured gain of 4.73, 1.66, and 3.28 dBi for 2.4, 3.5, and 5.8 GHz, respectively. The radiation characteristics have proven that the proposed antenna seems to be a good potential candidate for WLAN/WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2209–2214, 2013
Low‐Pass Features of Optical Nano‐Filters Constituted by Simple Layered Structures
Authors: Valagiannopoulos Constantinos A. , Sihvola Ari
Published: June 2013

Low‐pass filtering in the nanoscale is a significant procedure that has recently attracted considerable attention due to the upsurge of state‐of‐the‐art nanophotonic applications. In this work, two consecutive dielectric layers with specific permittivity combination and certain size ratio are found to exhibit good performance as a low‐pass filter in the visible and at the nano‐frequencies. Despite its simplicity, the device retains a satisfying stability in terms of total transmission at the low frequencies; simultaneously, it is impenetrable for signals containing higher frequencies and is characterized by a lack of electromagnetic resonances. Several graphs verify these beneficial features of the structure and further conclusions related to its operation and functionality are obtained. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2099–2106, 2013
A Low Cost CP Printed Antenna Array For Portable L‐Band Satellite Data Terminals
Authors: Kalialakis Christos
Published: June 2013

A circularly polarized printed linear antenna array, fabricated in low cost FR4 substrate and suitable for L‐band satellite data terminals is presented. The main contributions of the article are twofold. First, a three times bandwidth increase compared to a single notched disc element is demonstrated through the utilization of aperture feeding and sequential rotation. Second, array configurations with small separations that can arise in situations with space constraints are investigated. Elements with modified dimensions were found to be a simple and efficient remedy that mitigates the effect of mutual coupling. The suitability of the array for its use in L‐band satellite data terminals with reduced pointing requirements is also discussed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2015–2019, 2013
A Comparative Study of Two Numerical Techniques To Analyze Double Screen Frequency Selective Surface
Authors: Silva Tercio L. , Campos Antonio L. P. S. , d'Assunção Adaildo G. , Maniçoba Robson H. C.
Published: June 2013

A comparative study of two techniques to analyze double screen frequency selective surface (FSS) is presented. The FSS are composed with perfectly conducting rectangular patch elements. Numerical and experimental results are presented. The two techniques are the scattering matrix (SM) and the spectral domain analysis. The study allowed us to set up main advantages and constraints of these techniques and define which one should be used for particular FSS geometries and conditions. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2206–2209, 2013
Experimental Verification of Passive Optical Network With Ring Topology
Authors: Lafata Pavel , Vodrážka Jiří
Published: June 2013

Today, tree or hybrid tree‐star topologies are mostly used for passive optical networks in practice. However, these topologies are significantly vulnerable against the failures of a central optical line termination (OLT) unit. Recently, an innovative idea about forming a simple ring topology by using asymmetric passive splitters together with secondary OLT unit has been presented and an elementary mathematical model for calculations of optimum splitting ratios of all splitters in a ring infrastructure has been described. The major advantage of presented ring topology is that both primary and secondary OLT units can be placed on the opposite sides of the ring, which could greatly increase the overall resistance of the whole network against critical failures, malfunctions, or sophisticated attacks. Next, this ring topology was successfully realized in practice by using real OLT and optical network units and the whole idea verified. The results of real measurements as well as theoretical calculations are presented in this article. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2201–2205, 2013
Adaptive Optics Integrated Surface Roughness Measurement of Sputtered PT Film on Silicon Substrate
Authors: Fuh Yiin Kuen , Wang Chia He
Published: June 2013

A new optical inspection system for in situ surface roughness measurement of sputtered Pt film on silicon is developed. In this study, we present an in‐process measurement of surface roughness by combining an optical probe of laser‐scattering phenomena and adaptive optics (AO) for aberration correction. The aim of this study was to demonstrate the necessity for AO compensation in regions containing turbulences. Measurement results of eight Pt film on top of P‐type silicon wafer samples with a roughness ranging from 58 to 83 nm demonstrate excellent correlation between the peak power and average roughness with a correlation coefficient (R2) of 0.9963. The proposed AO‐assisted system is in good agreement with stylus method and less than 0.70% error values are obtained for the aforementioned average sample roughness. The proposed system can be used as a rapid in‐process roughness monitor to further improve the stability of thin film–sputtering processes in situ. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2055–2059, 2013
A Dual‐Mode Split Microstrip Resonator and Its Applications in Frequency Selective Devices
Authors: Belyaev Boris A. , Serzhantov Aleksey M. , Tyurnev Vladimir V.
Published: June 2013

A dual‐mode microstrip resonator whose strip conductor is partially split from its one end by a longitudinal slot has been studied. The resonator has two fundamental modes, even and odd ones. The difference of their frequencies is controlled by varying the slot length. Based on such resonators, original structures of a diplexer and passband filters including dual‐band have been designed. Measured performances of their fabricated prototypes prove applicability of designed devices in microwave engineering. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2186–2190, 2013
Design of Compact Bandpass Filter with Controllable Multiple Transmission Zeros using The Second‐Order Inductive‐Coupled Resonator
Authors: Huang Hui‐Hsiang , Horng Tzyy‐Sheng
Published: June 2013

This article proposes new synthetic design approach for a compact LTCC bandpass filter (BPF) with three transmission zeros over a wide stopband operating in the 2.4–2.5 GHz WLAN band. The BPFs have two feedback paths, one for a grounding inductor and one for a coupling capacitor, to provide controllable multiple transmission zeros at 1.07 and 5.05 GHz stopband, which suppresses the 0.82–0.96 GHz GSM850/GSM900 band and 4.8–5.0 GHz second harmonic band of the operating frequency. The presented design derives compact formulas for synthesizing a filter to meet the specification requirement. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2155–2157, 2013
Validation of the rotterdam MOVE2PC questionnaire for assessment of nurses' knowledge and opinions on palliative care
Authors: Witkamp Frederika E. , van Zuylen Lia , van der Rijt Carin C.D. , van der Heide Agnes
Published: June 2013

The purpose of this study was the psychometric testing of a questionnaire to assess nurses' opinions, subjective norms, perceived difficulties, and knowledge related to palliative care. The 63‐item MOVE2PC Questionnaire was tested among 219 nurses in groups differing in education and experience. The intra‐rater agreement was moderate to good (к > .5κmax), and internal consistency was good (alpha = .77). Construct validity was demonstrated by between‐groups differences in knowledge, opinions, and perceived difficulties. Responsiveness was shown by improved scores after an education program. Time of completion was 20 minutes, and 99% skipped at most five items, demonstrating feasibility. Findings support the usefulness of the instrument for assessing nurses' knowledge and views on palliative care. © 2013 Wiley Periodicals, Inc. Res Nurs Health 36: 512–523, 2013.
Random walks which prefer unvisited edges: Exploring high girth even degree expanders in linear time
Authors: Berenbrink Petra , Cooper Colin , Friedetzky Tom
Published: June 2013

Let be a connected graph with vertices. A simple random walk on the vertex set of G is a process, which at each step moves from its current vertex position to a neighbouring vertex chosen uniformly at random.

We consider a modified walk which, whenever possible, chooses an unvisited edge for the next transition; and makes a simple random walk otherwise. We call such a walk an edge‐process (or E‐process). The rule used to choose among unvisited edges at any step has no effect on our analysis. One possible method is to choose an unvisited edge uniformly at random, but we impose no such restriction.

For the class of connected even degree graphs of constant maximum degree, we bound the vertex cover time of the E‐process in terms of the edge expansion rate of the graph G, as measured by eigenvalue gap of the transition matrix of a simple random walk on G.

A vertex v is ℓ‐good, if any even degree subgraph containing all edges incident with v contains at least ℓ vertices. A graph G is ℓ‐good, if every vertex has the ℓ‐good property. Let G be an even degree ℓ‐good expander of bounded maximum degree. Any E‐process on G has vertex cover time

urn:x-wiley:10429832:media:rsa20504:rsa20504-math-0004

This is to be compared with the lower bound on the cover time of any connected graph by a weighted random walk. Our result is independent of the rule used to select the order of the unvisited edges, which could, for example, be chosen on‐line by an adversary.

As no walk based process can cover an n vertex graph in less than n – 1 steps, the cover time of the E‐process is of optimal order when . With high probability random r‐regular graphs, even, have . Thus the vertex cover time of the E‐process on such graphs is . © 2013 Wiley Periodicals, Inc. Random Struct. Alg., 46, 36–54, 2015
Primary gastric synovial sarcoma: molecular diagnosis and prediction of prognosis
Authors: Kamata Kohsuke , Wada Ryuichi , Yajima Nobuhisa , Sawada Mitsuhiro , Wakasa Haruki , Yagihashi Soroku
Published: June 2013

A 42-year-old Japanese woman complained of upper abdominal pain. Endoscopic examination demonstrated an elevated lesion in the body of the stomach, and a biopsy specimen demonstrated proliferation of atypical spindle cells. She underwent partial gastrectomy; the resected tumor measured 3.5 × 2.8 × 1.2 cm in size. Histological examination disclosed the haphazard proliferation of spindle cells in the mucosa mixed with less prominent epithelioglandular component. The spindle cells were positive for cytokeratin, vimentin, EMA and CD99, but not for KIT, DOG1, desmin or S100. Reverse transcription-polymerase chain reaction using paraffin sections amplified a SYT-SSX1 chimera transcript. A diagnosis of synovial sarcoma was made. There has been no sign of recurrence or metastasis for 6 years after the operation. Synovial sarcoma in the stomach is very rare. Since differential diagnosis of synovial sarcoma from carcinosarcoma and mesenchymal tumors is critical for the treatment and prediction of prognosis, accurate diagnosis with molecular analysis is essential.
Temperature and the catalytic activity of enzymes: A fresh understanding
Authors: Daniel Roy M. , Danson Michael J.
Published: June 2013

The discovery of an additional step in the progression of an enzyme from the active to inactive state under the influence of temperature has led to a better match with experimental data for all enzymes that follow Michaelis–Menten kinetics, and to an increased understanding of the process. The new model of the process, the Equilibrium Model, describes an additional mechanism by which temperature affects the activity of enzymes, with implications for ecological, metabolic, structural, and applied studies of enzymes.
Calcium binding by the PKD1 domain regulates interdomain flexibility in Vibrio cholerae metalloprotease PrtV
Authors: Edwin Aaron , Rompikuntal Pramod , Björn Erik , Stier Gunter , Wai Sun N. , Sauer-Eriksson A. Elisabeth
Published: June 2013

Vibrio cholerae, the causative agent of cholera, releases several virulence factors including secreted proteases when it infects its host. These factors attack host cell proteins and break down tissue barriers and cellular matrix components such as collagen, laminin, fibronectin, keratin, elastin, and they induce necrotic tissue damage. The secreted protease PrtV constitutes one virulence factors of V. cholerae. It is a metalloprotease belonging to the M6 peptidase family. The protein is expressed as an inactive, multidomain, 102 kDa pre‐pro‐protein that undergoes several N‐ and C‐terminal modifications after which it is secreted as an intermediate variant of 81 kDa. After secretion from the bacteria, additional proteolytic steps occur to produce the 55 kDa active M6 metalloprotease. The domain arrangement of PrtV is likely to play an important role in these maturation steps, which are known to be regulated by calcium. However, the molecular mechanism by which calcium controls proteolysis is unknown. In this study, we report the atomic resolution crystal structure of the PKD1 domain from V. cholera PrtV (residues 755–838) determined at 1.1 Å. The structure reveals a previously uncharacterized Ca2+‐binding site located near linker regions between domains. Conformational changes in the Ca2+‐free and Ca2+‐bound forms suggest that Ca2+‐binding at the PKD1 domain controls domain linker flexibility, and plays an important structural role, providing stability to the PrtV protein.
Signal-dependent fra-2 regulation in skeletal muscle reserve and satellite cells
Authors: Alli N S , Yang E C , Miyake T , Aziz A , Collins-Hooper H , Patel K , McDermott J C
Published: June 2013

Activator protein-1 (AP-1) is a ubiquitous transcription factor that paradoxically also has some tissue-specific functions. In skeletal muscle cells, we document that the AP-1 subunit, Fra-2, is expressed in the resident stem cells (Pax7-positive satellite cells) and also in the analogous undifferentiated ‘reserve’ cell population in myogenic cultures, but not in differentiated myofiber nuclei. Silencing of Fra-2 expression enhances the expression of differentiation markers such as muscle creatine kinase and myosin heavy chain, indicating a possible role of Fra-2 in undifferentiated myogenic progenitor cells. We observed that Fra-2 is a target of cytokine-mediated extracellular signal-regulated kinase-1/2 signaling in cultured muscle cells, and extensive mass spectrometry and mutational analysis identified S320 and T322 as regulators of Fra-2 protein stability. Interestingly, Fra-2 S320 phosphorylation occurs transiently in activated satellite cells and is extinguished in myogenin-positive differentiating cells. Thus, cytokine-mediated Fra-2 expression and stabilization is linked to regulation of myogenic progenitor cells having implications for the molecular regulation of adult muscle stem cells and skeletal muscle regeneration.
Mineralocorticoid receptors and the heart, multiple cell types and multiple mechanisms: a focus on the cardiomyocyte
Authors: Bienvenu Laura A. , Reichelt Melissa E. , Delbridge Lea M. D. , Young Morag J.
Published: June 2013

MR (mineralocorticoid receptor) activation in the heart plays a central role in the development of cardiovascular disease, including heart failure. The MR is present in many cell types within the myocardium, including cardiomyocytes, macrophages and the coronary vasculature. The specific role of the MR in each of these cell types in the initiation and progression of cardiac pathophysiology is not fully understood. Cardiomyocyte MRs are increasingly recognized to play a role in regulating cardiac function, electrical conduction and fibrosis, through direct signal mediation and through paracrine MR-dependent activity. Although MR blockade in the heart is an attractive therapeutic option for the treatment of heart failure and other forms of heart disease, current antagonists are limited by side effects owing to MR inactivation in other tissues (including renal targets). This has led to increased efforts to develop therapeutics that are more selective for cardiac MRs and which may have reduced the occurrence of side effects in non-cardiac tissues. A major clinical consideration in the treatment of cardiovascular disease is of the differences between males and females in the incidence and outcomes of cardiac events. There is clinical evidence that female sensitivity to endogenous MRs is more pronounced, and experimentally that MR-targeted interventions may be more efficacious in females. Given that sex differences have been described in MR signalling in a range of experimental settings and that the MR and oestrogen receptor pathways share some common signalling intermediates, it is becoming increasingly apparent that the mechanisms of MRs need to be evaluated in a sex-selective manner. Further research targeted to identify sex differences in cardiomyocyte MR activation and signalling processes has the potential to provide the basis for the development of cardiac-specific MR therapies that may also be sex-specific.