bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of polyaniline coated polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) microparticles and the further fabrication of hollow polyaniline microspheres
Authors: Sun Libo , Shi Yuanchang , Chu Linya , Xu Xiaokuai , Liu Jiurong
Published: April 2012

In this article, the microparticles of polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) (PS‐PSS) coated by polyaniline (PANI) were prepared and hollow PANI microspheres were further obtained by dissolving the core. First, surface‐sulfonated monodispersed PS was prepared by copolymerization of sodium 4‐styrenesulfonate (SSS) and styrene with dispersion polymerization method. Then aniline was polymerized on the surface of the surface‐sulfonated PS (PS‐PSS) by chemical oxidative polymerization. After purification, we prepared core‐shell (PS‐PSS)/PANI particles. Hollow PANI microspheres were prepared by dissolving the plastic PS core of the (PS‐PSS)/PANI particles in chloroform. The growth process of PANI on the surface of PS‐PSS particles was investigated and the hollow PANI microspheres were characterized. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polypyrrole–multiwalled carbon nanotubes composites as immobilizing matrices of ascorbate oxidase for the facile fabrication of an amperometric vitamin C biosensor
Authors: Li Dong , Wen Yangping , He Haohua , Xu Jingkun , Liu Ming , Yue Ruirui
Published: April 2012

An amperometric vitamin C biosensor was facilely fabricated by the immobilization of ascorbate oxidase (AO) on polypyrrole (PPy)–multiwalled carbon nanotubes (MWCNTs) composites with a one‐step electrodeposition technique in a 0.05M phosphate buffer solution (pH 6.5). The cyclic voltammetry, IR spectral analysis, electrochemical impedance spectroscopy, and scanning electron microscopy measurements indicated that AO was successfully immobilized on the PPy–MWCNT composites. The optimization of the biosensor parameters, including the working potential, pH, and temperature, was investigated in detail. The proposed biosensor showed a linear range of 5 × 10−5 to 2 × 10−2
M with a detection limit of 0.3 μM, a sensitivity of 25.9 mA mM−1 cm−2, and a current response time less than 20 s under the optimized conditions. The apparent Michaelis–Menten constant together with the apparent activation energy indicated that the proposed biosensor exhibited a high bioaffinity and a good enzyme activity. In addition, the biosensor also showed good operational and storage stabilities. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polymer‐modified bitumen of recycled LDPE and maleated bitumen
Authors: Singh B. , Kumar Lokesh , Gupta M. , Chauhan G. S.
Published: April 2012

Maleated bitumen was prepared by the reaction of penetration grade bitumen (80/100) with maleic anhydride at 150°C for 2 h under nitrogen atmosphere. The effectiveness of maleation was assessed in bitumen–recycled low‐density polyethylene (LDPE) blends in terms of their softening point and elastic recovery. It was observed that the softening point and elastic recovery of the blends increased after maleation of the base bitumen owing to the formation of an asphaltene‐linked‐LDPE system. To obtain the desired elasticity, a recoverable composition was worked out with the help of maleated bitumen, recycled LDPE and styrene–butadiene–styrene. The storage stability of the blends was assessed in terms of their difference in softening points, rheological parameters, and microstructure of the top and bottom portions of test tube samples. The difference in softening point of the recoverable maleated bitumen blend was 5°C as compared to 60°C for the base bitumen blend. The phase angle was also reduced to 7.4° at 70°C compared with the 44.30° for the base bitumen blend. Scanning electron micrographs indicate that polymers existed in both the top and the bottom portions of the aged test tube maleated blend samples. The stability of the blend was further improved when LDPE is colloidal milled with maleic anhydride in the blend preparation. Roofing bitumen was also made with maleated bitumen containing 9 wt % recycled LDPE content. Based on the rheological data, it was found that the maleated bitumen–LDPE blend exhibited superior time‐/temperature‐dependent response and higher creep recovery compared with the base bitumen blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Void ratio and durability properties of porous polymer concrete using recycled aggregate with binder contents for permeability pavement
Authors: Sung Chan‐Yong , Kim Young‐Ik
Published: April 2012

Particularly in Korea, where most roads are paved with impermeable materials such as asphalt and cement concrete, problems arise such as increased flooding as result of rainwater flowing into urban streams and the depletion of underground water. In recent years, there has been a great deal of ongoing research concerning water permeability and drainage in pavements. Accordingly, in this research, a porous polymer concrete was developed by using unsaturated polyester resin as a binder, recycled aggregate as coarse aggregate, fly ash and blast‐furnace slag as filler for permeable pavement, and its physical and mechanical properties were investigated. Regardless of the type of filler and amount of binder, the standard void ratio of 8% specified in the mixture of permeable asphalt was exceeded. In all mixes, regardless of the type of filler and amount of binder, the standard compressive strength for permeable concrete of 18 MPa was exceeded. Also, in all mixes, the standard permeability coefficient of 1.0 × 10−2 cm/s for permeable asphalt mixture was exceeded. The weight reduction ratio of the porous polymer concrete that was submerged in 10% sulfuric acid solution was 1.17 to 2.3%, and it was found that there was virtually no weight reduction. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structural differences between wood species: Evidence from chemical composition, FTIR spectroscopy, and thermogravimetric analysis
Authors: Poletto Matheus , Zattera Ademir J. , Santana Ruth M. C.
Published: April 2012

In this study, the relationship between wood cellulose crystallinity, influence of extractives on wood degradation, correlation between chemical composition, and physical properties of four wood species were investigated by chemical analysis, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetry. The chemical analysis showed that Dipteryx odorata and Mezilaurus itauba (ITA) contained a higher quantity of extractives and lower quantities of holocellulose and lignin than Eucalyptus
grandis (EUG) and Pinus elliottii. FTIR spectroscopy indicated that higher extractives content in ITA might be associated with more intense bands at 2920, 2850, and 1510 cm−1. The lower values for hydrogen bond energy and hydrogen bond intensity showed that EUG contained more absorbed water than the other species. Thermogravimetry confirm that lower extractive contents leads to a better wood thermal stability. This study showed that through the methods used previous information about structure and properties of wood can be obtained before use it in composite formulations. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation of optical and thermally stimulated properties of SiO2 nanoparticles‐filled polycarbonate
Authors: Rathore Bhupendra Singh , Gaur Mulayam Singh , Singh Kripa Shanker
Published: April 2012

Polycarbonate nanocomposite containing silicon oxide nanoparticles average size of 5 nm at different weight ratio has been prepared by solution mixing method. The dispersion of nanoparticles in polymer matrix was studied by transmission electron microscopy (TEM). The optical and thermally stimulated behavior of nanocomposites were analyzed by energy dispersive X‐ray spectra (EDX), X‐ray diffraction pattern (XRD), UV–vis spectroscopy, differential scanning calorimetry (DSC), and thermally stimulated discharge current (TSDC). TEM images show the dispersion and size of the nanoparticles, however, EDX indicate the presence of SiO2 on the surface of the nanocomposite film. An XRD result reveals that the crystallinity increases with increase in concentration of SiO2 nanoparticles in polymer matrix. The direct and indirect optical energy band gaps decreased and number of carbon atom increased with concentration of SiO2 nanoparticles. We have observed that the increase of SiO2 nanoparticles in PC significantly reduces the refractive index. DSC and TSDC show that glass transition temperature increases according to SiO2 weight ratio. The TSDC of nanocomposites samples could be understand in terms of non‐Debye theory of charge relaxation and co‐tunneling mechanism of charge transport. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Automated selection and harvesting of pluripotent stem cell colonies
Authors: Haupt Simone , Grützner Jan , Thier Marc‐Christian , Kallweit Tobias , Rath Barbara Helen , Laufenberg Iris , Forgber Michael , Eberhardt Jens , Edenhofer Frank , Brüstle Oliver
Published: April 2012

The ability of pluripotent stem cells to differentiate into specialized cells of all three germ layers, their capability to self‐renew, and their amenability to genetic modification provide fascinating prospects for the generation of cell lines for biomedical applications. Therefore, stem cells must increasingly suffice in terms of industrial standards, and automation of critical or time‐consuming steps becomes a fundamental prerequisite for their routine application. Cumbersome manual picking of individual stem cell colonies still represents the most frequently used method for passaging or derivation of clonal stem cell lines. Here, we explore an automated harvesting system (CellCelector™) for detection, isolation, and propagation of human embryonic stem cells (hESCs) and murine induced pluripotent stem cells (iPSCs). Automatically transferred hESC colonies maintained their specific biological characteristics even after repeated passaging. We also selected and harvested primary iPSCs derived from mouse embryonic fibroblasts expressing the green fluorescent protein (GFP) under the control of the Oct4 promotor using either morphological criteria or GFP fluorescence. About 80% of the selected and harvested primary iPSC colonies gave rise to homogenously GFP‐expressing iPSC lines. To validate the iPSC lines, we analyzed the expression of pluripotency‐associated markers and multi‐germ layer differentiation potential in vitro. Our data indicate that the CellCelector™ technology enables efficient identification and isolation of pluripotent stem cell colonies at the phase contrast or fluorescence level.
Genetically engineered stem cell‐based strategies for articular cartilage regeneration
Authors: Santhagunam Aruna , Madeira Catarina , Cabral Joaquim M. S.
Published: April 2012

Cartilage is frequently injured, often as a result of inflammatory rheumatic diseases or sports‐related trauma. Given its nonvascular nature, articular cartilage has a limited capability for self‐repair and currently the few therapeutic options still have uncertain long‐term outcomes. Cell‐based surgical therapies using autologous chondrocytes to repair cartilage injury have been used in the clinic for over a decade, but this approach has shown mixed results mainly due to the low number of harvested chondrocytes and the loss of cartilage‐related phenotype and functionality after several passages of in vitro culture. A wide range of cell sources have been tested to circumvent chondrocyte limitations in cartilage repair, and stem cells have been presented as those that offer the greatest potential for clinical application. This review will focus on recent advances in stem cell‐based strategies for articular cartilage repair, specifically focusing on the use of genetically engineered adult stem cells by conventional gene delivery methods and by gene‐activated matrices. Perspectives in cartilage engineering are also addressed.
Procyanidins and inflammation: Molecular targets and health implications
Authors: Martinez‐Micaelo Neus , González‐Abuín Noemi , Ardèvol Anna , Pinent Montserrat , Blay Maria Teresa
Published: April 2012

The inflammatory response has been implicated in the pathogenesis of many chronic diseases. Thus, the modulation of the inflammatory response by the consumption of bioactive food compounds, such as procyanidins, is a powerful tool to promote health. Procyanidin‐mediated anti‐inflammatory molecular mechanisms include, among others, the modulation of the arachidonic acid pathway, the inhibition of the gene transcription, protein expression and enzymatic activity of eicosanoid generating enzymes, the production and secretion of inflammatory mediators (such as cytokines and nitric oxide), the inhibition of mitogen‐activated protein kinase (MAPK) pathway activation, and the modulation of the nuclear factor‐κB (NF‐κB) pathway. The NF‐κB pathway can be regulated by procyanidins at several levels. During early events in NF‐κB signaling, procyanidins modulate Iκκ activity, and the cytoplasmic retention of p65:p50 NF‐κB by the inhibition of IκB phosphorylation and proteasomal degradation, while at late stages, they affect the nuclear translocation of pro/anti‐inflammatory NF‐κB homo/hetero dimers and their subsequent binding to the promoter regions of target genes. To identify and understand the value of procyanidins in the modulation of the inflammatory response, the molecular mechanisms underlying the anti‐inflammatory activities and prohomeostatic effects of procyanidins need to be investigated further. © 2012 International Union of Biochemistry and Molecular Biology, Inc.
Microglial physiopathology: how to explain the dual role of microglia after acute neural disorders?
Authors: Gomes‐Leal Walace
Published: April 2012

Microglia are the resident macrophages of the central nervous system (CNS). In physiological conditions, resting microglia maintain tissue integrity by scanning the entire CNS parenchyma through stochastic and complex movements of their long processes to identify minor tissue alterations. In pathological conditions, over‐activated microglia contribute to neuronal damage by releasing harmful substances, including inflammatory cytokines, reactive oxygen species, and proteinases, but they can provide tissue repair by releasing anti‐inflammatory cytokines and neurotrophic factors. The reasons for this apparent paradox are unknown. In this paper, we first review the physiological role as well as both detrimental and beneficial actions of microglial during acute CNS disorders. Further, we discuss the possible reasons for this microglial dual role following CNS insults, considering that the final microglial phenotype is a direct consequence of both noxious and beneficial stimuli released into the extracellular space during the pathological insult. The nature of these micro‐glial ligands is unknown, but we hypothesize that harmful and beneficial stimuli may be preferentially located at specific anatomical niches along the pathological environment triggering both beneficial and deleterious actions of these glial cells. According to this notion, there are no natural populations of detrimental microglia, but is the pathological environment that determines the final microglial phenotype.
Bilateral quadruple renal arteries
Authors: Miclaus Gratian D. , Matusz Petru
Published: April 2012

Variation in the number of renal arteries (RAs) constitutes the most common and clinically important renal vascular variation. In this study, the authors describe a rare case of a 58‐year‐old male with eight RAs (bilateral quadruple) as revealed by routine multidetector computed tomography angiography. All the eight RAs originated from the abdominal aorta and penetrated the renal parenchyma at the level of renal sinus. The main RAs had the intraluminal diameter larger than the diameter of the additional renal arteries (AdRAs) at the origin. All the AdRAs had a greater length than the main RAs. These aspects are particularly important in planning microsurgical procedures. Clin. Anat. 25:973–976, 2012. © 2012 Wiley Periodicals, Inc.
Percutaneous coronary revascularization in coronary artery disease: Lessons from a single center experience
Authors: Aksoy Olcay , Tuzcu E. Murat , Ellis Stephen G. , Whitlow Patrick L. , Cam Akin , Batizy Lillian , Agarwal Shikhar , Franco Irving , Bajzer Christopher , Simpfendorfer Conrad , Raymond Russell , Nair Ravi , Cho Leslie , Shishehbor Mehdi H. , Lincoff A. Michael , Kapadia Samir R.
Published: April 2012

Objectives

To determine the role of percutaneous coronary intervention (PCI) and its impact on mortality in coronary artery disease (CAD).

Background

It's unclear whether PCI provides benefit in patients with CAD outside of acute settings. We sought to determine the role of PCI and its effect on mortality in patients with similar entry criteria to prior RCTs and compare outcomes with medical treatment.

Methods

Using institutional diagnostic catheterization database of consecutive patients undergoing coronary angiography from 1/2004 to 1/2010, we examined records for patients with a positive stress test and >70% coronary stenosis or symptoms of angina and >80% coronary stenosis. We excluded those with acute coronary syndromes, low ejection fraction (EF), history of CABG, and CABG following index catheterization. We stratified patients by treatment and performed unadjusted and propensity matched analyses. The outcome was all‐cause mortality obtained from the social security death index.

Results

We identified 3,375 patients using study inclusion criteria. Mean age was 65 ± 11 years and 69% (n = 2,332) were men. Mean EF was 55% ± 8%. In the unadjusted cohort, 1,265 patients received medical management and 2,110 received PCI. The unadjusted analysis revealed significantly better survival in PCI patients (P < 0.0001) (HR: 0.51; 95% confidence interval (CI), 0.41–0.63). Propensity matching was performed for 1,580 patients and analysis showed better survival among patients receiving PCI (0 = 0.04) (HR: 0.74; 95% CI, 0.55–0.98). PCI continued to show better survival after excluding patients with malignancy (P = 0.03) and unstable angina (P = 0.007).

Conclusions

This single center registry analysis demonstrated better survival in stable CAD patients undergoing PCI compared to medical management alone. These data suggest there may be a benefit of PCI beyond symptom relief. Future randomized trials are needed to further understand the role of PCI in broader patient populations. © 2012 Wiley Periodicals, Inc.
A near‐infrared spectroscopy computational model for cerebral hemodynamics
Authors: Kannan R. , Przekwas A.
Published: April 2012

Near infrared spectroscopy (NIRS) is a technique used to detect and measure changes in the concentrations of oxygenated hemoglobin, deoxygenated hemoglobin, and water in tissues based on the differential absorption, scattering, and refraction of the near infrared light. In this imaging technique, the optical properties of tissues are reconstructed from the measurements obtained from the sensors located on the boundary. A computational method for the rapid noninvasive detection ∕ quantification of cerebral hemorrhage is described using the above procedure. CFD Research Corporation's finite volume computational biology code was used to numerically mimic the NIRS procedure by (i) noninvasively ‘numerically penetrating’ the brain tissues and (ii) reconstructing the optical properties the presence of water, oxygenated, and deoxygenated blood. These numerical noninvasive measurements are then used to predict the extent and severity of the brain hemorrhage. The paper also discusses ideas to obtain the location and the severity of a localized injury. Two‐dimensional and three‐dimensional simulations are performed as a proof of concept for the numerical formulation being feasible for the above mentioned detection/quantification. The results demonstrate that this numerical NIRS formulation can be used as a noninvasive technique for both qualitative and quantitative evaluation of cerebral hemodynamics. Copyright © 2012 John Wiley & Sons, Ltd.
Flow cytometry‐based assessment of mitoxantrone efflux from leukemic blasts varies with response to induction chemotherapy in acute myeloid leukemia
Authors: Kim Hyun Pyo , Bernard Lea , Berkowitz Jonathan , Nitta Janet , Hogge Donna E.
Published: April 2012

Background:

Accurate prediction of chemotherapy drug resistance would aid treatment decisions in acute myeloid leukemia (AML). The aim of this study was to determine if mitoxantrone efflux from AML blasts would correlate with response to induction chemotherapy.

Methods:

Flow cytometry was used to measure the median fluorescence intensity (MFI) for AML blasts incubated with mitoxantrone [an ATP‐binding cassette (ABC) transporter substrate] with or without coincubation with cyclosporine A (a broad‐spectrum inhibitor of ABC transporters) and a ratio (MFIR) between the inhibited and uninhibited MFI was calculated.

Results:

Among 174 AML patient blast samples, the mean MFIR for complete remission (CR) patients was lower than that obtained for induction failure (IF) patients (mean MFIR ± SD 1.62 ± 0.53 for CR after one cycle of chemotherapy vs. 2.22 ± 1.29 for CR after two cycles and 2.59 ± 0.98 for IF, P < 0.001). Logistic regression analysis determined 2.45 as the MFIR threshold above which 29% of patients achieved CR vs. a CR rate of 84% when the MFIR was ≤ 2.45 (P < 0.0001). In AML patients with normal karyotype (n = 80), CR was obtained for 33% of patients with an MFIR > 2.45 vs. 89% of those with MFIR ≤ 2.45 (P < 0.0001). In patients > age 60 (n = 77), 30% vs. 87% of those with MFIR > vs. ≤ 2.45 achieved CR (P < 0.0001).

Conclusions:

This assay of ABC transporter function can potentially predict response to induction chemotherapy in AML. © 2012 International Clinical Cytometry Society
Targeted Drug Delivery––Quo Vadis?
Authors: Petrak Karel
Published: April 2012

Strategy, Management and Health Policy

Enabling Technology, Genomics, Proteomics
Preclinical Research
Preclinical Development Toxicology, Formulation Drug Delivery, Pharmacokinetics
Clinical Development Phases I‐III Regulatory, Quality, Manufacturing
Postmarketing Phase IV

While business predictions suggest that 19 companies will have new or improved targeted drug delivery products on the market by 2018, no effective drug‐targeting systems have as yet been developed for use as human therapeutics despite a steadily increasing number of publications on the topic of drug targeting. This critical review argued that efforts in this field have failed so far largely because the basic requirements of targeted drug delivery are not been taken into consideration by researchers. The review outlines a systematic approach that should be adopted starting with determining whether the drug under consideration could benefit from site‐selective targeting based on its pharmacokinetic and pharmacodynamic behavior and on the physiological properties of the intended target site. A drug delivery system should advance to in vivo toxicity and efficacy testing only after it has been shown that it imparts to the drug the required pharmacokinetic properties.
Incorporation of Beclomethasone Dipropionate into Polyethylene Glycol‐Diacyl Lipid Micelles as a Pulmonary Delivery System
Authors: Sahib Mohanad Naji , Darwis Yusrida , Peh Kok Khiang , Abdulameer Shaymaa Abdalwahed , Fung Tan Yvonne Tze
Published: April 2012

Strategy, Management and Health Policy

Enabling Technology, Genomics, Proteomics
Preclinical Research
Preclinical Development Toxicology, Formulation Drug Delivery, Pharmacokinetics
Clinical Development Phases I‐III Regulatory, Quality, Manufacturing
Postmarketing Phase IV

Nebulized corticosteroid drugs have several shortcomings due to their poor water solubility and nonoptimal deposition pattern. The aims of this study were to investigate the in vitro and in vivo characteristics of beclomethasone dipropionate (BDP)‐loaded sterically stabilized phospholipid nanomicelles (SSMs) of a polyethylene glycol–phosphatidylethanolamine conjugate as a pulmonary delivery system. The particle size distribution and zeta potential measurements were 14.60 ± 1.11 nm and −46.94 ± 3.27 mV, respectively. The solubility of BDP was highly improved by at least 1,300 times its actual solubility. No chemical interaction was found between the PEGylated polymer and BDP as demonstrated by the Fourier transform infrared results. The in vitro aerodynamic of the aerosolized BDP‐SSMs using an Omron nebulizer showed an improvement in the aerodynamic values, with a significant deposition in the seven‐stage Next Generation Impactor. The BDP‐SSMs showed a prolonged dissolution profile of about 3 days. Intratracheal administration of the BDP‐SSMs (1 mg/kg) 12 or 23 h before a challenge in the asthmatic rat model led to a significant reduction in the inflammatory cell counts in bronchoalveolar lavage fluid samples compared with the administration of solubilized BDP. The SSM system appears to be an effective way of improving the therapeutic index of nebulized, poorly soluble corticosteroids.
Rapid shrinkage and hydrological response of a typical continental glacier in the arid region of northwest China – taking Urumqi Glacier No.1 as an example
Authors: Sun Meiping , Li Zhongqin , Yao Xiaojun , Jin Shuang
Published: April 2012

Small glaciers are more sensitive to climate change and can drive remarkable runoff variation in local catchments. Here, the recent shrinkage and hydrological response of Urumqi Glacier No.1, a typical continental glacier, situated in the arid region of northwest China, were investigated using glacier data, hydrological and meteorological data collected near the glacier during the past 50 years. The results showed that annual air temperature and precipitation increased by 0·9 °C and 91 mm (17.5%), respectively. Glacier length shortened by about 215·2 m (9·7%) and its area diminished by 0·304 km2 (15·6%). The cumulative mass balance of the glacier was −13 693 mm, equivalent to 15·2 m of glacier ice. Annual glacier runoff calculated by using a water balance model and the runoff measured at the outflow gauging station increased remarkably. The percentage of the increased river flow being derived from the increased glacier runoff reached 69·7% especially after 1994. Temperature and precipitation during the ablation season were the governing factors affecting the runoff at the glacierized (Glacier No.1) and non‐glacierized (Empty Cirque) catchments, respectively. Temperature rise and precipitation increase between 1959 and 2008 have had a combined effect on glacier mass loss and runoff change. Copyright © 2012 John Wiley & Sons, Ltd.
Corona characteristics of distribution line in contact with conductive material and life estimation of conductor insulation
Authors: Yamashita Takahiko , Fujishima Tomoyuki , Kuba Hiroyuki
Published: April 2012

In relation to accidents due to bird nests in contact with overhead distribution lines, the authors investigated the life estimation of conductor insulation. Accidents are often caused by crows or magpies. There is a region in which magpies have been designated a protected bird in Japan. In that region, the nests cannot be easily removed in the breeding season. Recently, metal wires have been used as nest material. When this conductive material is in contact with a distribution line and arm, a corona discharge will occur. The conductor insulation of the distribution line suffers deterioration and there is a possibility of causing an accident. In this study, an acceleration test was performed to investigate the time from nest building to an accident in the distribution line. The acceleration factor based on the charge amount of the corona and the influence of the applied voltage on corona characteristics was discussed. The life of the conductor insulation was discussed in terms of the V–t characteristics and the acceleration factor. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(4): 25–32, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21260
High‐precision positioning with strain feedback using piezoelectric element
Authors: Seki Kenta , Mochizuki Keisuke , Iwasaki Makoto , Hirai Hiromu
Published: April 2012

This paper presents a novel control methodology for robust high‐precision positioning systems. This methodology is based on strain feedback using a piezoelectric element. The mechanical vibration modes at around the control bandwidth cause deterioration of system stability. This prevents the positioning performance from being robust, particularly against variations in the vibration frequency. In this research, therefore, a robust positioning system was designed by applying an additional compensation loop by strain feedback; here, a piezoelectric element that acts as a strain sensor detects the vibration signal. This makes the performance of the system robust. The proposed compensation approach has been verified by numerical analyses and by experiments using a positioning device for industrial galvano scanners. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(4): 41–50, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21267
Effective capacity optimization for multiuser diversity systems with adaptive transmission
Authors: Harsini Jalil S. , Lahouti Farshad
Published: April 2012

The effective capacity (EC) for a wireless system expresses the maximum arrival source rate that the system can reliably transmit over the wireless channel while fulfilling a probabilistic delay constraint. This paper presents an EC optimization for a multiuser diversity system exploiting proportional opportunistic scheduling at the medium access control layer in conjunction with adaptive modulation and coding (AMC) at the physical layer. We consider the downlink of a time‐slotted multiuser system with two different types of channel state information (CSI) at the transmitter, that is, (i) full CSI, whereby each user feeds back its normalized signal‐to‐noise ratio to the transmitter and (ii) quantized CSI, where each user feeds back the AMC mode for transmission. For each case, we first derive the EC function of the queue service process for the individual users at the medium access control layer. We then design the AMC scheme with power control aiming at maximizing the said function subject to a target packet‐error rate constraint. Both independent and identically distributed and time‐correlated fading channels are considered. The results illustrate the superior performance of the proposed schemes, when compared with the previous systems such as opportunistic scheduling with single‐rate transmission and round‐robin scheduling with AMC. Copyright © 2012 John Wiley & Sons, Ltd.
Energy‐efficient exploration and exploitation of multichannel diversity in spectrum sharing systems
Authors: Xu Yuhua , Shen Liang , Anpalagan Alagan , Wu Qihui , Wang Jinlong , Xu Yitao
Published: April 2012

This letter investigates the problem of energy‐efficient exploration and exploitation of multichannel diversity in spectrum sharing cognitive radio systems where the secondary user sequentially explores the channel state information on the licenced channels with time and energy consumptions. As the number of the explored channels increases, the achieved multichannel diversity gain increases and so does the exploration consumption. Thus, there is a fundamental tradeoff between the multichannel diversity gain and channel exploration overhead. To maximise the expected normalised capacity of the secondary user, we formulate this tradeoff as an optimal stopping problem and propose a myopic one‐stage look‐ahead rule to solve it. It is shown that the one‐stage look‐ahead rule is optimal in the low power region; moreover, it also has good performance in general power region. Simulation results show that the achievable normalised throughput differs greatly for different exploration overhead, which can be regarded as a distinct feature of spectrum sharing systems. Copyright © 2012 John Wiley & Sons, Ltd.
Examining Markers in 8q24 to Explain Differences in Evidence for Association With Cleft Lip With/Without Cleft Palate Between Asians and Europeans
Authors: Murray Tanda , Taub Margaret A. , Ruczinski Ingo , Scott Alan F. , Hetmanski Jacqueline B. , Schwender Holger , Patel Poorav , Zhang Tian Xiao , Munger Ronald G. , Wilcox Allen J. , Ye Xiaoqian , Wang Hong , Wu Tao , Wu‐Chou Yah Huei , Shi Bing , Jee Sun Ha , Chong Samuel , Yeow Vincent , Murray Jeffrey C. , Marazita Mary L. , Beaty Terri H.
Published: April 2012

In a recent genome‐wide association study (GWAS) from an international consortium, evidence of linkage and association in chr8q24 was much stronger among nonsyndromic cleft lip/palate (CL/P) case‐parent trios of European ancestry than among trios of Asian ancestry. We examined marker information content and haplotype diversity across 13 recruitment sites (from Europe, United States, and Asia) separately, and conducted principal components analysis (PCA) on parents. As expected, PCA revealed large genetic distances between Europeans and Asians, and a north‐south cline from Korea to Singapore in Asia, with Filipino parents forming a somewhat distinct Southeast Asian cluster. Hierarchical clustering of SNP heterozygosity revealed two major clades consistent with PCA results. All genotyped SNPs giving P < 10−6 in the allelic transmission disequilibrium test (TDT) showed higher heterozygosity in Europeans than Asians. On average, European ancestry parents had higher haplotype diversity than Asians. Imputing additional variants across chr8q24 increased the strength of statistical evidence among Europeans and also revealed a significant signal among Asians (although it did not reach genome‐wide significance). Tests for SNP‐population interaction were negative, indicating the lack of strong signal for 8q24 in families of Asian ancestry was not due to any distinct genetic effect, but could simply reflect low power due to lower allele frequencies in Asians. Genet. Epidemiol. 36:392–399, 2012. © 2012 Wiley Periodicals, Inc.
Emotional expressions in voice and music: Same code, same effect?
Authors: Escoffier Nicolas , Zhong Jidan , Schirmer Annett , Qiu Anqi
Published: April 2012

Scholars have documented similarities in the way voice and music convey emotions. By using functional magnetic resonance imaging (fMRI) we explored whether these similarities imply overlapping processing substrates. We asked participants to trace changes in either the emotion or pitch of vocalizations and music using a joystick. Compared to music, vocalizations more strongly activated superior and middle temporal cortex, cuneus, and precuneus. However, despite these differences, overlapping rather than differing regions emerged when comparing emotion with pitch tracing for music and vocalizations, respectively. Relative to pitch tracing, emotion tracing activated medial superior frontal and anterior cingulate cortex regardless of stimulus type. Additionally, we observed emotion specific effects in primary and secondary auditory cortex as well as in medial frontal cortex that were comparable for voice and music. Together these results indicate that similar mechanisms support emotional inferences from vocalizations and music and that these mechanisms tap on a general system involved in social cognition. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Synthesis of 1‐acetoxy‐2‐aminoakenes via condensation of amino with carbonyl and CC acetoxylation
Authors: Liu Wei‐Bing , Chen Cui , Zhang Qing
Published: April 2012

1‐Acetoxy‐2‐aminoakenes were synthesized through an effective synthetic route using acid as the catalyst and (diacetoxyiodo)benzene as the oxidant, which is also a novel strategy for the formation of two C‐heteroatom bonds in the same reaction. In addition, it is a practical protocol with high regioselectivity, atom efficiency, and good substrate scope. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:290–294, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21016
Synergistic interaction of dietary cholesterol and dietary fat in inducing experimental steatohepatitis
Authors: Savard Christopher , Tartaglione Erica V. , Kuver Rahul , Haigh Geoffrey W. , Farrell Geoffrey C. , Subramanian Savitha , Chait Alan , Yeh Matthew M. , Quinn LeBris S. , Ioannou George N.
Published: April 2012

The majority of patients with nonalcoholic fatty liver disease (NAFLD) have “simple steatosis,” which is defined by hepatic steatosis in the absence of substantial inflammation or fibrosis and is considered to be benign. However, 10%-30% of patients with NAFLD progress to fibrosing nonalcoholic steatohepatitis (NASH), which is characterized by varying degrees of hepatic inflammation and fibrosis, in addition to hepatic steatosis, and can lead to cirrhosis. The cause(s) of progression to fibrosing steatohepatitis are unclear. We aimed to test the relative contributions of dietary fat and dietary cholesterol and their interaction on the development of NASH. We assigned C57BL/6J mice to four diets for 30 weeks: control (4% fat and 0% cholesterol); high cholesterol (HC; 4% fat and 1% cholesterol); high fat (HF; 15% fat and 0% cholesterol); and high fat, high cholesterol (HFHC; 15% fat and 1% cholesterol). The HF and HC diets led to increased hepatic fat deposition with little inflammation and no fibrosis (i.e., simple hepatic steatosis). However, the HFHC diet led to significantly more profound hepatic steatosis, substantial inflammation, and perisinusoidal fibrosis (i.e., steatohepatitis), associated with adipose tissue inflammation and a reduction in plasma adiponectin levels. In addition, the HFHC diet led to other features of human NASH, including hypercholesterolemia and obesity. Hepatic and metabolic effects induced by dietary fat and cholesterol together were more than twice as great as the sum of the separate effects of each dietary component alone, demonstrating significant positive interaction. Conclusion: Dietary fat and dietary cholesterol interact synergistically to induce the metabolic and hepatic features of NASH, whereas neither factor alone is sufficient to cause NASH in mice. (Hepatology 2013)
Soft Immobilization of Proteins onto Single‐Walled Carbon Nanotubes through Nickel Complexed Nitrilotriacetic Acid‐End Functionalized Polystyrenes
Authors: Kadir Mohammad Abdul , Park Jin‐hong , Kim Bong‐Soo , Lee Sun‐Gu , Paik Hyun‐jong
Published: April 2012

We describe the immobilization of histidine‐tagged green fluorescent protein (His6‐GFP) specifically and reversibly onto single‐walled carbon nanotubes (SWCNTs) using nickel complexed nitrilotriacetic acid‐end functionalized polystyrene (Ni‐NTA‐PS) by conjugation between the protein and the polymer in phosphate buffer solution (PBS). We synthesized Ni‐NTA‐PS by atom transfer radical polymerization (ATRP) using a nitrilotriacetic acid (NTA) initiator. The SWCNTs were dispersed in PBS along with Ni‐NTA‐PS and His6‐GFP aided by sonication. The diameter of the dispersed SWCNTs was measured by transmission electron microscope (TEM). The immobilization of His6‐GFP and dispersion of SWCNTs were controlled by addition of excess imidazole. It was found that the immobilized His6‐GFP was more stable than free His6‐GFP in organic solvent (PBS/DMF, 1/1, v/v).
DNA hybridization assay at individual, biofunctionalized zinc oxide nanowires
Authors: Leiterer Christian , Seise Barbara , Slowik Irma , Brönstrup Gerald , Niepelt Raphael , Weber Karina , Ronning Carsten , Christiansen Silke , Fritzsche Wolfgang
Published: April 2012

Reliable and efficient identification of DNA is a major goal in on‐site diagnostics. One dimensional nanostructures like nanowires (NW) represent potential sensor structures due to their extreme surface‐to‐bulk ratio, enabling enhanced biomolecule binding which results in optimal signals. While silicon NW are already well studied, NW made from other materials with promising properties like ZnO are not yet established as NW sensor material for bioanalytics. Here we demonstrate the DNA functionalization of ZnO NW even at the single NW level and their successful application in a DNA hybridization assay. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transcriptomic and proteomic analyses in bone tumor cells: Deciphering parathyroid hormone-related protein regulation of the cell cycle and apoptosis
Authors: Mak Isabella WY , Turcotte Robert E , Ghert Michelle
Published: April 2012

Giant cell tumor of bone (GCT) is an aggressive skeletal tumor characterized by local bone destruction, high recurrence rates, and metastatic potential. Previous works in our laboratory, including functional assays, have shown that neutralization of parathyroid hormone-related protein (PTHrP) in the cell environment inhibits cell proliferation and induces cell death in GCT stromal cells, indicating a role for PTHrP in cell propagation and survival. The objective of this study was to investigate the global gene and protein expression patterns of GCT cells in order to identify the underlying pathways and mechanisms of neoplastic proliferation provided by PTHrP in the bone microenvironment. Primary stromal cell cultures from 10 patients with GCT were used in this study. Cells were exposed to optimized concentrations of either PTHrP peptide or anti-PTHrP neutralizing antiserum and were analyzed with both cDNA microarray and proteomic microarray assays in triplicate. Hierarchical clustering and principal component analyses confirmed that counteraction of PTHrP in GCT stromal cells results in a clear-cut gene expression pattern distinct from all other treatment groups and the control cell line human fetal osteoblast (hFOB). Multiple bioinformatics tools were used to analyze changes in gene/protein expression and identify important gene ontologies and pathways common to this anti-PTHrP–induced regulatory gene network. PTHrP neutralization interferes with multiple cell survival and apoptosis signaling pathways by triggering both death receptors and cell cycle–mediated apoptosis, particularly via the caspase pathway, TRAIL pathway, JAK-STAT signaling pathway, and cyclin E/CDK2-associated G1/S cell cycle progression. These findings indicate that PTHrP neutralization exhibits anticancer potential by regulating cell-cycle progression and apoptosis in bone tumor cells, with the corollary being that PTHrP is a pro-neoplastic factor that can be targeted in the treatment of bone tumors. © 2012 American Society for Bone and Mineral Research.
Efficient 2,2,6,6‐Tetramethylpiperidine‐1‐oxyl/iron Catalyzed Aerobic Dehydrogenation of Hexanitrobibenzyl to Hexanitrostilbene
Authors: Lu Ting‐ting , Lu Ming
Published: April 2012

Hexanitrostilbene (HNS) was efficiently produced through the dehydrogenation of hexanitrobibenzyl (HNBB) with oxygen catalyzed by 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)/ferrous chloride (FeCl2) in 80% yield, and up to a 308 turnover number was achieved. First, TEMPO is used in the dehydrogenation and the influence of reaction time, temperature, solvent and the catalyst were discussed. A possible mechanism of this catalytic process is proposed and it is obtained that Fe(II) can abstract hydrogen from HNBB and the function of the function of TEMPO is to oxidize Fe(II)OOH to Fe(III)OO.
A New Mode of Homogeneous Liquid–liquid Microextraction (HLLME) Based on Ionic Liquids: In Situ Solvent Formation Microextraction (ISFME) for Determination of Lead
Authors: Hosseini Mehdi , Dalali Nasser , Nejad Saeid Mohammad
Published: April 2012

A simple in situ solvent formation microextraction method based on use of ionic liquid (IL) as an extractant solvent and sodium hexafluorophosphate (NaPF6) as an ion‐pairing agent was proposed for the concentration of trace levels of lead. In this method lead was complexed with N‐phenylbenzo‐hydroxamic acid (PBHA) and extracted into an ionic liquid phase. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry. ISFME is a fast, simple and suitable method for extraction and concentration of inorganic such as metal ions from sample solutions containing a high concentration of salts. The influences of the analytical parameters on the microextraction efficiency were investigated and optimized. Under the optimum conditions, the limit of detection (3s) and the enhancement factor were 0.1 μg L−1 and 70, respectively. The relative standard deviation (R.S.D) was obtained 1.3%. The accuracy of the method was confirmed by analyzing certified reference materials. The presented method was successfully applied for the determination of lead in water samples.
Electrochemical Monitoring of Photoelectrocatalytic Degradation of 3,4‐Dichlorophenol Using TiO2 Thin Film Modified Graphite Electrode
Authors: Ojani Reza , Raoof Jahan‐Bakhsh , Zarei Ebrahim
Published: April 2012

A novel electrode was prepared by forming TiO2 thin films using a commercially available TiO2 powder (Degussa P25) on graphite plates for water photoelectrocatalytic decontamination. In addition to, for the first time the photoelectrochemical degradation of 3,4‐dichlorophenol was investigated. The effects of applied potential, pH, and initial 3,4‐dichlorophenol concentration on the photoelectrocatalytic (PEC) degradation of 3,4‐dichlorophenol using ultraviolet (UV) illuminated TiO2/graphite (TiO2/C) thin film electrode was examined and discussed. Also, direct photolysis (DP), electrochemical oxidation (EC), photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of 3,4‐dichlorophenol were compared. Results show that the best responses for PEC are obtained at applied potential 1.2 V versus reference electrode, pH 8.0 and initial 3,4‐dichlorophenol concentration 6.7 mg L−1.
Trityl Chloride (TrCl): Efficient and Homogeneous Organocatalyst for the Solvent‐Free Synthesis of 14‐Aryl‐14H‐dibenzo[a,j]xanthenes by in situ Formation of Carbocationic System
Authors: Zare Abdolkarim , Merajoddin Maria , Abi Fereshteh , Moosavi‐Zare Ahmad Reza , Mokhlesi Mohammad , Zolfigol Mohammad Ali , Asgari Zhila , Khakyzadeh Vahid , Hasaninejad Alireza , Khalafi‐Nezhad Ali , Parhami Abolfath
Published: April 2012

Trityl chloride (triphenylmethyl chloride, TrCl, Ph3CCl) is utilized as an efficient and homogeneous organocatalyst for the synthesis of 14‐aryl‐14H‐dibenzo[a,j]xanthenes from β‐naphthol and arylaldehydes under solvent‐free conditions. Moreover, a plausible mechanism is suggested based on the literature and on in situ formation of trityl carbocation with inherent instability during the reaction.
Synthesis of Chiral Ionic Polymers Containing Quaternary Ammonium Sulfonate Structure and their Catalytic Activity in Asymmetric Alkylation
Authors: Parvez Md. Masud , Salam Md. Abdus , Haraguchi Naoki , Itsuno Shinichi
Published: April 2012

Repeated reaction between chiral quaternary ammonium dimer and disodium disulfonate gave the ionic polymer, which contains chiral quaternary ammonium sulfonate structure as a repeating unit. This chiral ionic polymer showed an excellent catalytic activity in asymmetric alkylation reaction. With the chiral ionic polymer catalysts, high level of enantioselectivities up to 97% ee were attained.