bluuebunny/crossref_metadata_2025 huggingface dataset:
Mu opioid receptor mRNA expression, binding, and functional coupling to G‐proteins in human epileptic hippocampus
Authors: Cuellar‐Herrera Manola , Velasco Ana Luisa , Velasco Francisco , Chavez Laura , Orozco‐Suarez Sandra , Armagan Guliz , Turunc Ezgi , Bojnik Engin , Yalcin Ayfer , Benyhe Sandor , Borsodi Anna , Alonso‐Vanegas Mario , Rocha Luisa
Published: November 2010

Mu opioid receptors (MOR) are known to be involved in seizure activity. The main goal of the present study was to characterize the MOR mRNA expression, binding, as well as G protein activation mediated by these receptors in epileptic hippocampus of patients with pharmacoresistant mesial temporal lobe epilepsy (TLE). In contrast with autopsy samples, hippocampus obtained from patients with mesial TLE demonstrated enhanced MOR mRNA expression (116%). Saturation binding experiments revealed significantly higher (60%)Bmaxvalues for the mesial TLE group, whereas theKdvalues were not statistically different. Although mesial TLE group demonstrated high levels of basal binding for the G proteins (136%), DAMGO‐stimulated [35S]GTPγS binding did not demonstrate significant alterations. In conclusion, our present data provide strong evidence that the epileptic hippocampus of patients with pharmacoresistant mesial TLE presents significant alterations in MOR. Such changes may represent adaptive mechanisms to compensate for other as yet unknown alterations. © 2010 Wiley Periodicals, Inc.
The effect of fluoride therapies on the morphology of bleached human dental enamel
Authors: Ferreira Stella da Silva , Araújo Jesuína Lamartine Nogueira , Morhy Omar Neves , Tapety Celiane Mary Carneiro , Youssef Michel Nicolau , Sobral Maria Angela Pita
Published: November 2010

The aim of this in vitro study was to evaluate qualitatively the surface morphology of enamel bleached with 35% hydrogen peroxide (HP) followed by application of fluoridated agents. Forty intact pre molars were randomly distributed into four groups (n = 10), treated as follows: Group I (control group) remained stored in artificial saliva at 37°C, Group II ‐ 35% HP; Group III ‐ 35% HP + acidulated fluoride (1.23%) and Group IV ‐ 35% HP + neutral fluoride (2%). The experimental groups received three applications of bleaching gel and after the last application all specimens were polished. This procedure was repeated after 7 and 14 days, and during the intervals of applications, the specimens were stored in artificial saliva at 37°C. Scanning electron microscopy (SEM) analysis showed superficial irregularities and porosities to varying degrees in bleached enamel compared to control group. Sample evaluation was made by attributing scores, and data were statistically analyzed using Kruskal–Wallis and Dunn tests (P < 0.05). SEM qualitative investigation demonstrated that 35% hydrogen peroxide affected human dental enamel morphology, producing porosities, depressions, and superficial irregularities at various degrees. These morphological changes were higher after the application of 1.23% acidulated fluoride gel. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.
Phosphorus speciation of forest‐soil organic surface layers using P K‐edge XANES spectroscopy
Authors: Prietzel Jörg , Thieme Jürgen , Paterson David
Published: November 2010

The phosphorus (P) speciation of organic surface layers from two adjacent German forest soils with different degree of water‐logging (Stagnosol, Rheic Histosol) was analyzed by P K‐edge XANES and subsequent Linear Combination Fitting. In both soils, ≈ 70% of the P was inorganic phosphate and ≈ 30% organic phosphate; reduced P forms such as phosphonate were absent. The increased degree of water‐logging in the Histosol compared to the Stagnosol did not affect P speciation.
Chemical fingerprint analysis of Phellodendri Amurensis Cortex by ultra performance LC/Q‐TOF‐MS methods combined with chemometrics
Authors: Li Yubo , Zhang Tiejun , Zhang Xiaolan , Xu Haiyu , Liu Changxiao
Published: November 2010

Ultra performance LC with quadrupole TOF MS (UPLC/Q‐TOF‐MS) fingerprinting is first developed for the identification of the major components of Phellodendri Amurensis Cortex (PAC). The PAC samples are separated using a Waters ACQUITY UPLC BEH C18 (2.1×50 mm, 1.7 μm) by linear gradient elution using water (containing 0.2% formic acid) and acetonitrile (containing 0.2% formic acid) as the mobile phase. Ten batches of PAC are selected to construct the UPLC/Q‐TOF‐MS fingerprint. Sixteen common peaks in the fingerprint are obtained, ten of which are tentatively identified, with reference to the literature data, as phellodendrine, magnoflorine, tetrahydropjatrorrhizine, menisperine, tetrahydropalmatine, jatrorrhizine, palmatine, berberine, obacunone, and limonin. Chemometric methods are also employed to evaluate the variation of herbal drugs and other closely related herbs based on the characteristics of peaks in the UPLC/Q‐TOF‐MS profiles. The developed fingerprint assay is a powerful method that may be used to conduct quality control of PAC.
Histogram analysis of the microvasculature of intracerebral human and murine glioma xenografts
Authors: Just Nathalie
Published: November 2010

The purpose of this study is to examine the usefulness of histogram analysis combined with vessel size index (VSI) magnetic resonance imaging for the specific characterization of brain tumor microvasculature in a panel of six volume‐matched glioma xenografts. Using a simple descriptive histogram analysis, significant differences of the mean tumoral VSI (P = 0.0035 for 9L, P = 0.008 for glioma mix, P = 0.05 for C6), the 75th VSI percentile (P = 0.003–0.075) as well as the 25th and median blood volume (BV) percentiles were found in murine gliomas compared to their contralateral healthy brain. Using a segmented histogram analysis, dilatation of already existing vessels in murine gliomas and development of new small caliber vessels in human glioblastomas were suggested. Most gliomas showed a higher proportion of pixels with BV below 1% (glioma mix [21% vs 1%], Glioblastoma 2 (GBM2) [9% vs 3.7%]) and a smaller proportion of pixels with BV in the range 1.7–6.3% (65 vs 90% for glioma mix, 80 vs 85% in GBM2) relative to their contralateral part. In glioblastomas, VSI and BV distributions were similar to normal brain distributions and in agreement with immunohistochemical findings. The histogram analysis of VSI and BV heterogeneity in experimental brain tumors allowed detection of microregional differences in gliomas from different origins. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Automated estimation of aortic strain from steady‐state free‐precession and phase contrast MR images
Authors: Herment Alain , Lefort Muriel , Kachenoura Nadjia , De Cesare Alain , Taviani Valentina , Graves Martin J. , Pellot‐Barakat Claire , Frouin Frédérique , Mousseaux Elie
Published: November 2010

The strain values extracted from steady‐state free‐precession (SSFP) and phase contrast (PC) images acquired with a 1.5T scanner on a compliant flow phantom and within the thoracic aorta of 52 healthy subjects were compared. Aortic data were acquired perpendicular to the aorta at the level of the pulmonary artery bifurcation. Cross sectional areas were obtained by using an automatic and robust segmentation method. While a good correlation (r = 0.99) was found between the aortic areas extracted from SSFP and PC sequences, a lower correlation (r = 0.71) was found between the corresponding aortic strain values. Strain values estimated using SSFP and PC sequences were equally correlated with age. Interobserver reproducibility was better for SSFP than for PC. Strain values in the ascending and descending aorta were better correlated for SSFP (r = 0.8) than for PC (r = 0.65) and fitted with the expectation of a larger strain in the ascending aorta when using SSFP. The spatial and temporal resolutions of the acquisitions had a minor influence upon the estimated strain values. Thus, if PC acquisitions can be used to estimate both pulse wave velocity and aortic strain, an additional SSFP sequence may be useful to improve the accuracy in estimating the aortic strain. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Respiratory bellows revisited for motion compensation: Preliminary experience for cardiovascular MR
Authors: Santelli Claudio , Nezafat Reza , Goddu Beth , Manning Warren J. , Smink Jouke , Kozerke Sebastian , Peters Dana C.
Published: November 2010

For many cardiac MR applications, respiratory bellows gating is attractive because it is widely available and not disruptive to or dependent on imaging. However, its use is uncommon in cardiac MR, because its accuracy has not been fully studied. Here, in 10 healthy subjects, the bellows and respiratory navigator (NAV) with the displacement of the diaphragm and heart were simultaneously monitored, during single‐shot imaging. Furthermore, bellows‐gated and NAV‐gated coronary MRI were compared using a retrospective reconstruction at identical efficiency. There was a strong linear relationship for both the NAV and the abdominal bellows with the diaphragm (R = 0.90 ± 0.05 bellows, R = 0.98 ± 0.01 NAV, P < 0.001) and the heart (R = 0.89 ± 0.06 bellows, R = 0.96 ± 0.02 NAV, P = 0.004); thoracic bellows correlated less strongly. The image quality of bellows‐gated coronary MRI was similar to NAV‐gated and superior to no‐gating (P < 0.01). In conclusion, bellows provides a respiratory monitor which is highly correlated with the NAV and suitable for respiratory compensation in selected cardiac MR applications. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Effects of endurance and strength‐directed electrical stimulation training on the performance and histological properties of paralyzed human muscle: A pilot study
Authors: Duffell Lynsey D. , Rowlerson Anthea M. , Donaldson Nick De N. , Harridge Stephen D.R. , Newham Di J.
Published: November 2010

Electrical stimulation (ES) improves muscle properties after spinal cord injury (SCI), but cycling power output (PO) remains low. We investigated the effect of endurance and strength ES training on these parameters. Assessments of quadriceps strength and fatigue resistance, cycling PO, and muscle biopsies were made in four well‐trained SCI subjects (three cyclists and one rower) before and after additional weight training in the cyclists and once in the rower. Weight training improved muscle strength, but cycling PO was low in all subjects. There was no effect of training type on biopsy data. Biopsies showed non‐specific signs of pathology, predominance of type IIa fibers, and uniform metabolic activity. Oxidative activity was low, as were capillary:fiber ratios in the cyclists. Cycling PO is limited by factors other than muscle strength. Future ES training studies should attempt to improve muscle oxidative capacity to optimize the potential benefits of ES exercise. Muscle Nerve 42: 756–763, 2010
Reproducibility of the motor unit number index (MUNIX) in normal controls and amyotrophic lateral sclerosis patients
Authors: Ahn Suk‐Won , Kim Su‐Hyun , Kim Jee‐Eun , Kim Sung‐Min , Kim Seung Hyun , Park Kyung Seok , Sung Jung‐Joon , Lee Kwang‐Woo , Hong Yoon‐Ho
Published: November 2010

The motor unit number index (MUNIX) refers to an electrophysiologic technique that measures the approximate number of motor units using the surface electromyographic interference pattern (SIP) recorded during voluntary contraction. This study was done to assess the reproducibility of MUNIX performed on hypothenar muscles in 62 normal controls and 22 amyotrophic lateral sclerosis (ALS) patients. Inter‐ and intraoperator correlation coefficients for MUNIX were 0.74 and 0.86, respectively, in normal controls, and 0.95 and 0.93, respectively, in ALS patients (P < 0.01 in all). Inter‐ and intraoperator coefficients of variation for MUNIX measurements were 17.5% and 15.3%, respectively, in normal controls, and 23.7% and 24.0%, respectively, in ALS patients. This study shows a good correlation for MUNIX between intra‐ and interoperator results in both normal controls and ALS patients. The test–retest variability seems to be greater in ALS patients compared with normal controls, but this will need to be confirmed in future studies. Sources of variability should be identified and corrected for clinical use. Muscle Nerve 42: 808–813, 2010
Motor unit number index (MUNIX): principle, method, and findings in healthy subjects and in patients with motor neuron disease
Authors: Nandedkar Sanjeev D. , Barkhaus Paul E. , StÅlberg Erik V.
Published: November 2010

The motor unit number index (MUNIX) is a method for assessment of number and size (MUSIX) of motor units (MUs) using the compound muscle action potential (CMAP) and surface electromyographic interference pattern (SIP). This method was used to study the hypothenar muscle in 34 healthy subjects to define normal range, and to study reproducibility. Four healthy subjects and 13 patients with amyotrophic lateral sclerosis (ALS) were studied serially over a 1‐year period. In healthy subjects, MUNIX showed good reproducibility. In serial studies, healthy subjects showed no change in the CMAP amplitude and MUNIX. ALS patients with minimal change in CMAP amplitude had a significant drop in MUNIX and increase in MUSIX, indicating MU loss compensated by reinnervation. When the CMAP changed significantly (>30%) in 1 year, the CMAP and MUNIX decreased in parallel. MUNIX would be useful to study MU loss in degenerative diseases of motor neurons. Muscle Nerve 42: 798–807, 2010
High‐dose carboplatin–irinotecan–temozolomide: Treatment option for neuroblastoma resistant to topotecan
Authors: Kushner Brian H. , Kramer Kim , Modak Shakeel , Cheung Nai‐Kong V.
Published: November 2010

Background

We report a retrospective study of a novel regimen for neuroblastoma (NB) resistant to standard induction or salvage chemotherapy which now routinely includes topotecan.

Patients and Methods

Forty‐five patients received carboplatin (500 mg/m2/day, 2×)–irinotecan (50 mg/m2/day, 5×)–temozolomide (250 mg/m2/day, 5×) (HD‐CIT). Only one course was planned. Patients with thrombocytopenia indicative of poor bone marrow (BM) reserve resulting from extensive prior therapy received peripheral blood stem cells (PBSCs) post‐HD‐CIT.

Results

Modest acute toxicity allowed outpatient treatment. Low‐grade diarrhea was common; there was no mucositis, nephrotoxicity, or cardiotoxicity. Myelosuppression was prolonged but uncomplicated. The absolute neutrophil count reached 500/µl on days 20–30 (median, 25) in 25 patients with satisfactory BM reserve, and on days 9–14 (median, 11) post‐PBSC infusion. Anti‐NB activity was common against refractory (non‐progressing) disease or new relapse occurring off therapy (68% objective response rate), but not against disease progressing on therapy. Seven of 26 patients treated for refractory NB are progression‐free and in complete remission following subsequent therapy, including anti‐GD2 immunotherapy, at ≥29+ months post‐HD‐CIT.

Conclusions

HD‐CIT is appealing as salvage or consolidative therapy because of anti‐NB activity and modest non‐hematologic toxicity. PBSC support is unnecessary when BM reserve is intact. The wide antineoplastic activity of its three components and their potential for activity against disease in the central nervous system support applicability to other cancers. Pediatr Blood Cancer 2011;56:403–408. © 2010 Wiley‐Liss, Inc.
Synthesis of starlike PtBA‐g‐PEO amphiphilic graft copolymer via highly efficient Cu‐catalyzed SET‐NRC reaction at ambient temperature
Authors: Li Yaogong , Zhang Yaqin , Zhai Sujuan , Deng Yan , Xiong Huiming , Lu Guolin , Huang Xiaoyu
Published: November 2010

Two new amphiphilic star graft copolymers bearing hydrophobic poly(tert‐butyl acrylate) backbone and hydrophilic poly(ethylene oxide) (PEO) side chains with different molecular weights were synthesized by sequential reversible addition fragmentation chain transfer (RAFT) polymerization and single electron transfer‐nitroxide radical coupling (SET‐NRC) reaction under mild conditions. RAFT homopolymerization of tert‐butyl 2‐((2‐bromopropanoyloxy)methyl)acrylate was mediated by a four‐armed chain transfer agent in a controlled way to afford a well‐defined starlike backbone with a narrow molecular weight distribution (Mw/Mn = 1.26). The target poly(tert‐butyl acrylate)‐g‐PEO (PtBA‐g‐PEO) star graft copolymers were synthesized by SET‐NRC reaction between Br‐containing PtBA‐based starlike backbone and PEO end functionalized with 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) group using copper/N,N,N′,N′,N″‐pentamethyldiethylenetriamine as catalytic system at ambient temperature via grafting‐onto strategy. The critical micelle concentration values of the obtained amphiphilic star graft copolymers in aqueous media and brine were determined by fluorescence probe technique using pyrene as probe. Diverse micellar morphologies were formed by varying the content of hydrophilic PEO segment as well as the initial concentration of stock solution. In addition, poly(acrylic acid)‐g‐PEO double hydrophilic star graft copolymers were obtained by selective acidic hydrolysis of hydrophobic PtBA starlike backbone without affecting PEO side chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Alternative initiators for bimolecular photoinitiating systems
Authors: Dworak Claudia , Liska Robert
Published: November 2010

Typical bimolecular photoinitiators (PIs) for radical polymerization of acrylates show only poor photoreactivity because of the unwanted effect of back electron transfer. Therefore, a PI system consisting of benzaldoxime esters and 4‐methyl benzophenone was investigated by photo‐differential scanning calorimetry experiments. Surprisingly, reactivities are comparable to that of classical monomolecular Type I PIs like Darocur 1173, probably because of an energy transfer from the triplet state of the benzophenone‐based sensitizer to the oxime ester initiator. Furthermore, sufficient thermal stability was proven by TGA and storage stability experiments of a resin formulation under elevated temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Sterically encumbered poly(arylene ether)s containing spiro‐annulated substituents: Synthesis and thermal properties
Authors: Huang Wen Y. , Chang M. Y. , Han Y. K. , Huang P. T.
Published: November 2010

Four novel 2‐trifluoromethyl‐activated bisfluoro monomers have been synthesized successfully using a Suzuki‐coupling reaction of 3‐trifluoromethyl‐4‐fluoro phenyl boronic acid with 2,7‐dibromofluorene with varied pendants. Four monomers were converted to a series of fluorene‐based poly(arylene ether)s with pendants by nucleophilic displacement of the fluorine atoms on the terminal benzene ring with 4,4′‐hexafluoroisopropylidenediphenol. The polymers obtained by displacement of the fluorine atoms, exhibit weight‐average molecular weight up to 9.89 × 104 g/mol in GPC. Thermal analysis studies indicated that these polymers did not show melting endotherms but did show relatively high Tg values up to 270 °C in DSC and outstanding thermal stability up to 532 °C for 5% weight loss in TGA in a nitrogen atmosphere. The polymers are soluble in a wide range of organic solvents: THF, CHCl3, NMP, DMAc, DMF, toluene and EAc, and so forth, at room temperature. Transparent and flexible films were easily prepared by solution casting from chloroform solution of each of the polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Rapid ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by titanium alkoxides
Authors: Zeng Jian‐Bing , Srinivansan Madhusudhan , Li Yi‐Dong , Narayan Ramani , Wang Yu‐Zhong
Published: November 2010

Ring‐opening polymerization of 1,4‐dioxan‐2‐one in bulk was initiated by three titanium alkoxides, titanium dichlorodiisopropoxide (TiCl2(OiPr)2), titanium chlorotriisopropoxide (TiCl(OiPr)3), and titanium tetraisopropoxide (Ti(OiPr)4). The results indicate that the polymerization rate increased with number of OiPr groups in the initiator. High conversion of monomer (90%) and high molecular weight (11.9 × 104 g/mol) of resulting polymer can be achieved in only 5 min at 60 °C with Ti(OiPr)4 as an initiator. Analysis on nuclear magnetic resonance (NMR) spectra suggests the initiating sites for TiCl2(OiPr)2, TiCl(OiPr)3, and Ti(OiPr)4 to be 1.9, 2.6, and 3.8, respectively. Coordination‐insertion mechanism for the polymerization via cleavage of the acyl–oxygen bonds of the monomer was proved by NMR investigation. Kinetic studies indicate that polymerization initiated by Ti(OiPr)4 followed a first‐order kinetics, with an apparent activation energy of 33.7 kJ/mol. It is noteworthy that this value is significantly lower than earlier reported values with other catalysts, namely La(OiPr)3 (50.5 kJ/mol) and Sn(Oct)2 (71.8 kJ/mol), which makes it an attractive catalyst for reactive extrusion polymerization. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Highly efficient and stable blue‐light‐emitting copolyfluorene consisting of carbazole, oxadiazole, and charge‐trapping anthracene groups
Authors: Chen Ruei‐Tang , Su Wen‐Fen , Chen Yun
Published: November 2010

This article presents the synthesis and electroluminescent (EL) properties of a stable blue‐light‐emitting copolyfluorene (P1) consisting of carbazole, oxadiazole and charge‐trapping anthracene groups by Suzuki coupling reaction. The hole‐transporting carbazole and electron‐transporting oxadiazole improve charges injection and transporting properties, whereas the anthracene is the ultimate emitting chromophore. The thermal, photophysical, electrochemical, and EL properties of P1 were investigated by thermogravimetric analysis, differential scanning calorimeter, optical spectroscopy, cyclic voltammetry, and EL devices fabrication and characterization. P1 demonstrated high‐thermal stability with thermal decomposition and glass tranistion temperatures above 400 and 145°C, respectively. In film state, P1 showed blue emission at 451 nm attributed to anthracene chromophore. Photophysical and electrochemical investigations demonstrate that effective energy transfer from fluorene to anthracene segments and charges trapping on anthracene segments leads to efficient and stable blue emission originating from anthracence. Polymer light‐emitting diodes using P1 as the emitting layer (ITO/PEDOT:PSS/P1/Ca/Al) exhibited excellent current efficiency (5.1 cd/A) with the CIE coordinate being (0.16, 0.11). The results indicate that copolyfluorene is a promising candidate for the blue‐emitting layer in the fabrication of efficient PLEDs. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
High Tg microspheres by dispersion copolymerization of N‐phenylmaleimide with styrenic or alkyl vinyl ether monomers
Authors: Krishnamoorthy Swapna , Haria Mehul , Fortier‐mcgill Blythe E. , Jafar Mazumder M. A. , Robinson Erica I. , Xia Yan , Burke Nicholas A. D. , Stöver Harald D. H.
Published: November 2010

Solution and dispersion copolymerizations of N‐phenylmaleimide (PMI) with either styrenics or alkyl vinyl ethers (AVEs), systems with a tendency to give alternating polymers, were investigated with the goal of producing high glass transition particles. Equimolar solution copolymerization of PMI with styrenics gave alternating copolymers, whereas AVEs gave PMI‐rich copolymers (∼65:35) except for t‐butyl vinyl ether, which gave copolymers with only a slight excess of PMI. These copolymers had glass transition temperatures (Tgs) ranging from 115 to 225 °C depending on comonomer(s). Dispersion copolymerization in ethanol‐based solvents in the presence of poly(vinylpyrrolidone) as steric stabilizer led to narrow‐disperse microspheres for many copolymers studied. Dispersion copolymeriations of PMI with styrenics required good cosolvents such as acetonitrile or methyl ethyl ketone as plasticizers during particle initiation and growth. Dispersion copolymerizations generally resulted in copolymer particles with compositions and Tgs very similar to those of the corresponding copolymers formed by solution polymerization, with the exception of t‐butyl vinyl ether (tBVE), which now behaved like the other AVEs. Dispersion terpolymerizations of PMI (50 mol %) with different ratios of either n‐butylstyrene and t‐butylstyrene or n‐butyl vinyl ether and tBVE led to polymer particles with Tgs that depended on the ratio of the two butyl monomers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Novel method controlled synthesis of silica coated carbon nanotubes
Authors: Chen Xuecheng , Cendrowski Krzysztof , Rümmeli Mark H. , Kalenczuk Ryszard J. , Borowiak‐Palen Ewa
Published: November 2010

In this contribution we present an easy and efficient method for the controlled synthesis of highly uniform silica coated coaxial carbon nanotubes (CNT). Furthermore, the thickness of silica wall, CNT, and the diameter of CNT could be controlled at will. This process involves the use of an anodized aluminum oxide (AAO) template to grow this molecular hybrid. After removal of the AAO template, free CNT@SiO2 nanotubes are obtained. Since silica is a light transparent, the combination of CNT and silica in one‐dimensional core–shell structures provides new oppotunities for photo‐electronic and functional applications.

magnified image

Scheme representing the synthesis route of CNT coated with silica.
From scientific practice to high school science classrooms: Transfer of scientific technologies and realizations of authentic inquiry
Authors: Waight Noemi , Abd‐El‐Khalick Fouad
Published: November 2010

The Biology Workbench (BW) is a web‐based tool enabling scientists to search a wide array of protein and nucleic acid sequence databases with integrated access to a variety of analysis and modeling tools. The present study examined the development of this scientific tool and its consequent adoption into the context of high school science teaching in the form of the Biology Student Workbench (BSW). Participants included scientists, programmers, science educators, and science teachers who played key roles along the pathway of the design and development of BW, and/or the adaptation and implementation of BSW in high school science classrooms. Participants also included four teachers who, with their students, continue to use BSW. Data sources included interviews, classroom observations, and relevant artifacts. Contrary to what often is advocated as a major benefit accruing from the integration of authentic scientific tools into precollege science teaching, classroom enactments of BSW lacked elements of inquiry and were teacher‐centered with prescribed convergent activities. Students mostly were preoccupied with following instructions and a focus on science content. The desired and actual realizations of BSW fell on two extremes that reflected the disparity between scientists' and educators' views on science, inquiry science teaching, and the related roles of technological tools. Research on large‐scale adoptions of technological tools into precollege science classrooms needs to expand beyond its current focus on teacher knowledge, skills, beliefs, and practices to examine the role of the scientists, researchers, and teacher educators who often are involved in such adoptions. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 48: 37–70, 2011
Influence of race and ethnicity on access to care among children with frequent ear infections
Authors: Bhattacharyya Neil , Shapiro Nina L. , Vakharia Kalpesh T.
Published: November 2010

OBJECTIVE

Determine the impact of racial/ethnic disparities on access to care for children with frequent ear infections (FEI). Identify disparities to target for intervention.

STUDY DESIGN

Cross‐sectional analysis of national database.

SETTING

Academic medical center.

SUBJECTS AND METHODS

The National Health Interview Survey (1997 to 2006) was utilized to identify children with FEI (defined as three or more ear infections in the preceding year). Age, sex, race/ethnicity, income level, and insurance status were extracted. Access to care was measured by ability to afford medical care and prescription medications, specialist visitation, and emergency department visits. Multivariate analysis determined the influence of demographic variables on the ability to access health care resources.

RESULTS

An annualized population of 4.65 ± 0.08 million children reported FEI. Overall, 3.7 percent could not afford care, 5.6 percent could not afford prescriptions, and only 25.8 percent saw a specialist. A larger percentage of the black (42.7%) and Hispanic children (34.5%) with FEI were below the poverty level, versus white children (12.4%; P < 0.001); 18.2 percent of Hispanic children were uninsured, versus 6.5 percent of white children (P < 0.001). On multivariate analysis, children with FEI that were black or Hispanic had increased odds ratios relative to white children for 1) not being able to afford prescription medications (odds ratios [OR] 1.76 and 1.47, respectively; P < 0.002); 2) not being able to see a specialist (OR 1.62 and 1.86, respectively; P < 0.001); and 3) visiting the emergency department (OR 2.50 and 1.32, respectively; P < 0.001).

CONCLUSION

Racial/ethnic disparities among children with FEI significantly influence health care resource access and utilization. These disparities should be targeted for intervention.
Comparison of otologic complications between intensity‐modulated and two‐dimensional radiotherapies in nasopharyngeal carcinoma patients
Authors: Hsin Chung‐Han , Chen Tsai‐Hsin , Young Yi‐Ho , Liu Wen‐Shan
Published: November 2010

OBJECTIVE

To investigate the otologic complications in patients with nasopharyngeal carcinoma (NPC) who were treated by intensity‐modulated radiotherapy (IMRT) and compared with those who were treated by two‐dimensional radiotherapy (2DRT).

STUDY DESIGN

A historical cohort study was performed comprising NPC patients who underwent IMRT or 2DRT at Chung Shan Medical University Hospital.

SETTING

Chung Shan Medical University Hospital.

SUBJECTS AND METHODS

Twenty‐six NPC patients treated by IMRT (group A) and 18 NPC patients treated by 2DRT (group B) were enrolled. All patients underwent otoscopy, audiometry, and a vestibular‐evoked myogenic potential (VEMP) test at a mean interval of three years after irradiation.

RESULTS

Although groups A and B did not significantly differ in the occurrence rate of otitis media with effusion (OME), group B had a significantly greater occurrence rate of chronic otitis media than group A (P < 0.05, χ2 test). The incidences of high‐frequency sensorineural hearing loss were 46 percent in group A and 67 percent in group B, with no significant difference between the two. In terms of VEMPs, group A had a significantly lower abnormal rate (31%) than group B (61%; P < 0.05, χ2 test). In addition, a significant relationship existed between T stages and OME in NPC patients treated by IMRT (P < 0.01, Fisher‐Freeman‐Halton test) but not by 2DRT.

CONCLUSION

The incidence of chronic otitis media and abnormal VEMPs in NPC patients treated by IMRT were significantly lower when compared with those treated by 2DRT, demonstrating the superiority of IMRT in decreasing unwanted otologic complications. However, occurrence of OME, which was related with advanced T stage, cannot be reduced by IMRT.
Multilingual Cosmopolitanism and Monolingual Commodification: Language Ideologies in Transnational Salsa Communities
Authors: Schneider Britta
Published: November 2010

Salsa, a global urban music and dance phenomenon, is an interesting example for the emergence of transnational cultural spheres. Salsa has its roots in the Americas and in many Salsa communities outside of Latin America, the Spanish language is seen as the authentic means of expression. However, attitudes to multilingualism can differ strongly from Salsa community to Salsa community.

In this paper, the Salsa-scene of Sydney is introduced with its various stances towards multilingualism. These are connected to different styles of the dance, where one style is practiced in English only, while dancers of another style are often bilingual speakers of Spanish and English. Monolingualism and multilingualism here mediate the affiliation to different local scenes. Simultaneously, both language ideologies relate to different global discourses of competitive and cosmopolitan culture. It will be asked whether the introduced language ideologies challenge traditional frameworks of society and reified discursive concepts of language. (Multilingualism – Transnationalism – Cosmopolitanism)*
Obesogens, stem cells and the maternal programming of obesity
Authors: Blumberg B.
Published: November 2010

Obesity and metabolic syndrome diseases have exploded into a global epidemic. Consumption of calorie-dense food and diminished physical activity are the generally accepted causes for obesity. But, could environmental factors expose preexisting genetic differences or exacerbate the root causes of diet and exercise? The environmental obesogen model proposes that chemical exposure during critical developmental stages influences subsequent adipogenesis, lipid balance and obesity. Obesogens are chemicals that stimulate adipogenesis and fat storage or alter the control of metabolism, appetite and satiety to promote weight gain. Tributyltin (TBT) is a high-affinity agonistic ligand for the retinoid X receptor (RXR) and peroxisome proliferator activated receptor gamma (PPARγ). RXR-PPARγ signaling is a key component in adipogenesis and the function of adipocytes; activation of this heterodimer increases adipose mass in rodents and humans. Thus, inappropriate activation of RXR-PPARγ can directly alter adipose tissue homeostasis. TBT exposure promoted adipocyte differentiation, modulated adipogenic genes and increased adiposity in mice after in utero exposure. These results suggest that organotin exposure is a previously unappreciated risk factor for the development of obesity and related disorders. Based on the observed effects of TBT on adipogenesis, we hypothesized that organotin exposure during prenatal adipose tissue development would create an environment that led to more adipocytes. We observed that the multipotent stromal cell compartment was altered by prenatal TBT exposure leading to an increased number of preadipocytes. This increase in the number of preadipocytes could correspondingly increase the steady state number of adipocytes in the adult, which could favor the development of obesity over time.
Hypertension artérielle et risque cardiovasculaire: l'hypothèse de la courbe en J
Authors: Yannoutsos  , Mourad  , Blacher  , Safar
Published: November 2010

Die Wichtigkeit einer optimalen Behandlung von Patienten mit arterieller Hypertonie wird durch vier Tatsachen unterstrichen: die hohe Prävalenz der arteriellen Hypertonie in der Bevölkerung, insbesondere bei älteren Personen; die nicht optimale Kontrolle der Blutdruckwerte bei mehr als der Hälfte der Patienten; das erhöhte kardiovaskuläre Restrisiko selbst unter Behandlung; und die häufige Assoziation mit anderen Herz-Kreislauf-Risikofaktoren, die das kardiovaskuläre Risiko der hypertonen Patienten weiter anhebt. Mehrere Interventionsstudien zeigten eine Risikoreduktion proportional zur Blutdruckreduktion unter Behandlung. Die Frage nach dem optimalen Zielblutdruck liegt entsprechend auf der Hand: die Richtlinien schlagen aktuell Blutdruckwerte unter 140/90 mmHg für die essentielle Hypertonie ohne Komplikationen, und Werte unter 130/80 mmHg für die Sekundärprophylaxe und bei diabetischen oder niereninsuffizienten Patienten vor. Die Vorteile der strikteren Kontrolle bei Hochrisikopatienten haben sich jedoch in grossen klinischen Studien nicht bestätigt, in gewissen Situationen scheint sie sogar schädlich zu sein. Das Dogma «the lower the better» wird entsprechend aufgegeben. Nichtsdestotrotz bleibt aber die seit mehr als drei Jahrzehnten existierende Hypothese der paradoxalen Erhöhung der kardiovaskulären Morbi-Mortalität bei zu tiefen Blutdruckwerten («J-Kurven-Hypothese») weiterhin kontrovers und Gegenstand vieler Studien.
Sinuous gullies on Mars: Frequency, distribution, and implications for flow properties
Authors: Mangold N. , Mangeney A. , Migeon V. , Ansan V. , Lucas A. , Baratoux D. , Bouchut F.
Published: November 2010

Recent gullies on Mars are suspected to be the result of liquid‐water‐bearing flows. A formation from wet flows has been challenged by studies invoking granular (dry) flows. Our study focuses on the sinuous shapes observed for some of the recent Martian gullies. Sinuous gullies are found in locations and slopes (of 10°–15°) similar to straight gullies, and they are therefore related to the same formation processes. Numerical simulations of granular flows are performed here by introducing topographic variations such as obstacles, roughness, or slope changes that could possibly generate flow sinuosity. None of these simulations was able to reproduce sinuous shapes on a slope lower than 18° with friction angles typical of dry granular material. The only way to simulate sinuous shapes is to create small‐amplitude periodic variations of the topography of the deposit, an origin not supported by current Martian imagery. Given the presence of sinuosity in natural terrestrial debris flows, we have concluded that sinuous Martian gullies are better reproduced by liquid‐water‐bearing debris flows. Sinuous shapes in leveed flows are used to derive mechanical parameters from several Martian gullies using photoclinometry. Values in yield strength of 100–2200 Pa, velocities of 1.1–3.3 m s−1, and viscosities from 40 to 1040 Pa s are found, which are all within the range of values for terrestrial debris flows with various proportions of liquid water (20%–40%).
Investigation of dust transport on the lunar surface in a laboratory plasma with an electron beam
Authors: Wang X. , Horányi M. , Robertson S.
Published: November 2010

There is much evidence indicating dust levitation and transport on or near the lunar surface. Dust mobilization is likely to be caused by electrostatic forces on charged lunar dust particles. We describe a series of experiments in which a small dust patch is placed on an electrically floating graphite surface in plasma. The effects of an electron beam on electric fields above/across the dust surface are studied for understanding the mechanism leading to dust transport. When the electron beam current is comparable to the Bohm ion current and the beam energy is sufficiently large, there is a large potential difference between the dust surface and the graphite surface, which creates a horizontal electric field that leads to dust mobilization. The vertical electric field in the sheath above the dust surface also increases at about an order of magnitude, significantly increasing the dust release rate. Differing secondary electron yields of the graphite surface and the dust patch play an important role in the enhancement of the electric fields. Imaging of JSC‐Mars‐1 dust placed on the graphite surface shows spreading of the dust and deposition on the top of an adjacent insulating block, indicating both horizontal and vertical dust transport.
Origin and evolution of fracture‐hosted methane hydrate deposits
Authors: Daigle Hugh , Dugan Brandon
Published: November 2010

Fracture‐hosted methane hydrate deposits exist at many sites worldwide. These sites often have hydrate present as vein and fracture fill, as well as disseminated through the pore space. We estimate that thousands to millions of years are required to form fracture systems by hydraulic fracturing driven by occlusion of the pore system by hydrate. This time scale is a function of rates of fluid flow and permeability loss. Low‐permeability layers in a sedimentary column can reduce this time if the permeability contrast with respect to the surrounding sediments is of order 10 or greater. Additionally, we find that tensile fracturing produced by hydrate heave around hydrate lenses is a viable fracture mechanism over all but the lowermost part of the hydrate stability zone. With our coupled fluid flow‐hydrate formation model we assess fracture formation at four well‐studied hydrate provinces: Blake Ridge offshore South Carolina, Hydrate Ridge offshore Oregon, Keathley Canyon Block 151 offshore Louisiana, and the Krishna‐Godavari Basin offshore India. We conclude that hydraulic fracturing due to pore pressure buildup is reasonable only at Hydrate Ridge and the Krishna‐Godavari Basin owing to sediment age constraints, and that hydrate‐filled fractures observed at Blake Ridge and Keathley Canyon Block 151 are formed either by hydrate heave or in preexisting fractures. Our findings offer new insight into the processes and time scales associated with fracture‐hosted hydrate deposits, which help further our understanding of hydrate systems.
Absence of Helicobacter pylori in Dental Plaque Determined by Immunoperoxidase
Authors: Savoldi Enrico , Marinone Maria Grazia , Negrini Riccardo , Facchinetti Daniela , Lanzini Alberto , Sapelli Pier Luigi
Published: November 2010

Background.

Attempts to detect Helicobacter pylori in dental plaque have given contrasting results, and the possibility of an oral‐oral transmission of the infection remains unclear. In this study, a sensitive and specific immunoperoxidase method has been employed to assess the presence of H. pylori in dental plaque.

Methods.

Dental plaque smears from 80 patients undergoing gastroscopy were analyzed by an indirect immunoperoxidase test, employing a mixture of two monoclonal antibodies against H. pylori.

Results.

No immunostained bacteria were shown in any of the examined dental plaque samples.

Conclusions.

H. pylori is not usually present in dental plaque, indicating that oral‐oral transmission of the infection could be due to intermittent esophageal reflux only.
The mongoose in Australia: failed introduction of a biological control agent
Authors: Peacock David , Abbott Ian
Published: November 2010

We reviewed historical literature and obtained nearly 200 records of the mongoose in Australia up to 1942. Although the earliest importations (from 1855) were for its snake-killing prowess, often as entertainment, its perceived potential as a control agent for the European rabbit (Oryctolagus cuniculus) plague saw concerted introductions made in New South Wales, Victoria and South Australia, primarily in 1883 and 1884. At least 1000 mongoose were released to control rabbits at 14 reported release locations in these states. As many as 700 of these mongoose were reported released in one New South Wales rabbit-control trial. These numbers indicate that insufficient propagule pressure does not explain why Australia escaped the additional devastation of an established mongoose population. The only reason stated for the failure of the mongoose releases to control rabbits is destruction of the mongoose by rabbit trappers, both inadvertently and in seeking to protect their employment. Unfavourable climate was implicated by CLIMATCH modelling in the failure of all releases, especially those into semiarid areas such as western New South Wales. No contemporary detail could be located of the reported 1884 failed introduction of ‘numbers’ of mongoose into North Queensland to control rats in sugarcane plantations.
Understanding the factors affecting the activation of alkane by Cp
′
Rh(CO)
2
(Cp
′
= Cp or Cp*)
Authors: George Michael W. , Hall Michael B. , Jina Omar S. , Portius Peter , Sun Xue-Zhong , Towrie Michael , Wu Hong , Yang Xinzheng , Zarić Snežana D.
Published: November 2010

Fast time-resolved infrared spectroscopic measurements have allowed precise determination of the rates of activation of alkanes by Cp′Rh(CO) (Cp
′
 = 
η
5
-C
5
H
5
or
η
5
-C
5
Me
5
). We have monitored the kinetics of C─H activation in solution at room temperature and determined how the change in rate of oxidative cleavage varies from methane to decane. The lifetime of CpRh(CO)(alkane) shows a nearly linear behavior with respect to the length of the alkane chain, whereas the related Cp*Rh(CO)(alkane) has clear oscillatory behavior upon changing the alkane. Coupled cluster and density functional theory calculations on these complexes, transition states, and intermediates provide the insight into the mechanism and barriers in order to develop a kinetic simulation of the experimental results. The observed behavior is a subtle interplay between the rates of activation and migration. Unexpectedly, the calculations predict that the most rapid process in these Cp′Rh(CO)(alkane) systems is the 1,3-migration along the alkane chain. The linear behavior in the observed lifetime of CpRh(CO)(alkane) results from a mechanism in which the next most rapid process is the activation of primary C─H bonds (─CH
3
groups), while the third key step in this system is 1,2-migration with a slightly slower rate. The oscillatory behavior in the lifetime of Cp*Rh(CO)(alkane) with respect to the alkane’s chain length follows from subtle interplay between more rapid migrations and less rapid primary C─H activation, with respect to CpRh(CO)(alkane), especially when the CH
3
group is near a
gauche
turn. This interplay results in the activation being controlled by the percentage of alkane conformers.
Rice pollen hybrid incompatibility caused by reciprocal gene loss of duplicated genes
Authors: Mizuta Yoko , Harushima Yoshiaki , Kurata Nori
Published: November 2010

Genetic incompatibility is a barrier contributing to species isolation and is caused by genetic interactions. We made a whole genome survey of two-way interacting loci acting within the gametophyte or zygote using independence tests of marker segregations in an F
2
population from an intersubspecific cross between
O. sativa
subspecies
indica
and
japonica
. We detected only one reproducible interaction, and identified paralogous hybrid incompatibility genes,
DOPPELGANGER1
(
DPL1
) and
DOPPELGANGER2
(
DPL2
), by positional cloning. Independent disruptions of
DPL1
and
DPL2
occurred in
indica
and
japonica
, respectively.
DPL
s encode highly conserved, plant-specific small proteins (∼10 kDa) and are highly expressed in mature anther. Pollen carrying two defective
DPL
alleles became nonfunctional and did not germinate, suggesting an essential role for
DPL
s in pollen germination. Although rice has many duplicated genes resulting from ancient whole genome duplication, the origin of this gene duplication was in recent small-scale gene duplication, occurring after
Oryza
-
Brachypodium
differentiation. Comparative analyses suggested the geographic and phylogenetic distribution of these two defective alleles, showing that loss-of-function mutations of
DPL1
genes emerged multiple times in
indica
and its wild ancestor,
O. rufipogon
, and that the
DPL2
gene defect is specific to
japonica
cultivars.
Evidence for viable, non-clonal but fatherless Boa constrictors
Authors: Booth Warren , Johnson Daniel H. , Moore Sharon , Schal Coby , Vargo Edward L.
Published: November 2010

Parthenogenesis in vertebrates is considered an evolutionary novelty. In snakes, all of which exhibit genetic sex determination with ZZ : ZW sex chromosomes, this rare form of asexual reproduction has failed to yield viable female WW offspring. Only through complex experimental manipulations have WW females been produced, and only in fish and amphibians. Through microsatellite DNA fingerprinting, we provide the first evidence of facultative parthenogenesis in a
Boa constrictor
, identifying multiple, viable, non-experimentally induced females for the first time in any vertebrate lineage. Although the elevated homozygosity of the offspring in relation to the mother suggests that the mechanism responsible may be terminal fusion automixis, no males were produced, potentially indicating maternal sex chromosome hemizygosity (WO). These findings provide the first evidence of parthenogenesis in the family Boidae (Boas), and suggest that WW females may be more common within basal reptilian lineages than previously assumed.