bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous Raman micro–spectroscopy of optically trapped and stacked cells
Authors: Jess P. R. T. , Garcés‐Chávez V. , Riches A. C. , Herrington C. S. , Dholakia K. 
Published: June 2007

AbstractThe combination of Raman spectroscopy and optical trapping holds great promise for single‐cell studies and is an emergent theme in microfluidic environments. Here, the evolution of the Raman signal intensity with an axial increment of the mass of the substance of interest inside a specific Raman excitation volume is investigated. Whilst Raman spectroscopy may be applied to tissue samples, solutions and single cells, there are no easily available methods to rapidly acquire signals from small cell populations. We show a simple but powerful method to record the Raman intensity signal simultaneously from a small number of trapped cells or colloidal particles using the technique of optical stacking. The Raman spectra of stacks of red blood cells and yeast cells show that this method can be applied to biological systems. We demonstrate how we may reveal biochemical fingerprints that would otherwise require long integration times for each single cell or averaging over many sequentially acquired cell spectra. There is potential to apply this method to directly attain Raman spectra from sorted sub‐populations of normal, abnormal and tumour cell lines. Copyright © 2007 John Wiley & Sons, Ltd.
Azoalkanes: A Novel Class of Additives for Cross‐Linking and Controlled Degradation of Polyolefins
Authors: Aubert Mélanie , Roth Michael , Pfaendner Rudolf , Wilén Carl‐Eric 
Published: June 2007

AbstractA series of symmetrical and unsymmetrical azoalkanes were synthesized and their potential as a free‐radical source for rheology modification of polyolefins was investigated. The experimental results show that unsymmetrical azoalkanes, in particular N‐cyclohexyl‐N'‐tert‐octyldiazene (13), can be successfully used for manufacturing controlled‐rheology poly(propylene) and cross‐linked high‐density polyethylene. For example, the melt flow rate of a general‐purpose poly(propylene) (MFR = 14) could be increased to a value of 800 when 0.75 wt.‐% of azoalkane 13 was added during reactive processing. In parallel, it was found that 13 has a remarkable efficiency for free‐radical‐induced cross‐linking of high‐density polyethylene, resulting in similar gel contents to dicumyl peroxide.magnified image
Effect of Sample Configuration on the Morphology of Foamed LDPE/PP Blends Injection Molded by a Gas Counterpressure Process
Authors: Kotzev Georgi , Djoumaliisky Strashimir , Krasteva Manya , Iliev Mario , Pérez Ernesto , Cerrada Maria Luisa 
Published: June 2007

AbstractBlends of isotactic poly(propylene) and low‐density polyethylene with different composition ratios were prepared through direct melt compounding on a twin‐screw extruder. The specimens with various geometric configurations were injection‐molded using a gas counterpressure process, using blends to which 0.5 wt.‐% of a blowing agent was added. The influence of blend composition and specimen geometry on the structure and morphology of the samples was investigated by SEM and WAXS. The thermal behavior of the blends was analyzed by DSC. It was found that the morphology of each region depended on the composition ratio and specimen geometry.magnified image
Stable Aqueous Dispersion of PEGylated Nanoparticles by Polyelectrolyte Complex Formation
Authors: Paneva Dilyana , Mespouille Laetitia , Bougard François , Manolova Nevena , Degée Philippe , Rashkov Iliya , Dubois Philippe 
Published: June 2007

AbstractStable aqueous dispersions of nanoparticles were prepared by polyelectrolyte complex formation between well‐defined poly(ethylene glycol)‐block‐poly(2‐acrylamido‐2‐methyl‐1‐propane sodium sulfonate) and poly(ethylene glycol)‐block‐poly[2‐(dimethylamino)ethyl methacrylate] diblock copolymers. Controlled synthesis of the copolymers was achieved by water‐based atom transfer radical polymerization (ATRP). The nanoparticles were characterized by a quite narrow and monomodal size distribution as evidenced by dynamic light scattering (DLS) and confirmed by atomic force microscopy (AFM) after solution casting and freeze‐drying.magnified image
The molecular biology and clinical features of amyloid neuropathy
Authors: Benson Merrill D. , Kincaid John C. 
Published: June 2007

AbstractNeuropathy is often a major manifestation of systemic amyloidosis. It is most frequently seen in patients with hereditary transthyretin (TTR) amyloidosis, but is also present in 20% of patients with systemic immunoglobulin light chain (primary) amyloidosis. Familial amyloid polyneuropathy (FAP) is the most common form of inherited amyloidotic polyneuropathy, with clinical and electrophysiologic findings similar to neuropathies with differing etiologies (e.g., diabetes mellitus). Hereditary amyloidosis is an adult‐onset autosomal‐dominant disease with varying degrees of penetrance. It is caused by specific gene mutations, but demonstration that a patient has one such mutation does not confirm the diagnosis of amyloidosis. Diagnosis requires tissue biopsy with demonstration of amyloid deposits either by special histochemical stains or electron microscopy. Transthyretin amyloidosis is treated by liver transplantation, which eliminates the mutated transthyretin from the blood, but for some patients continued amyloid deposition can occur from wild‐type (normal) transthyretin. Presently, a study is ongoing to determine whether amyloid deposition can be inhibited by small organic molecules that are hypothesized to affect the fibril‐forming ability of transthyretin. Proposed gene therapy with antisense oligonucleotides (ASOs) to suppress hepatic transthyretin synthesis is effective in a transgenic mouse model but has not yet been tested in humans. Muscle Nerve, 2007
Central activation, muscle performance, and physical function in men infected with human immunodeficiency virus
Authors: Scott Wayne B. , Oursler Krisann K. , Katzel Leslie I. , Ryan Alice S. , Russ David W. 
Published: June 2007

AbstractLoss of muscle mass and limitations in activity have been reported in persons infected with human immunodeficiency virus (HIV), even those who are otherwise asymptomatic. The extent to which factors other than muscle atrophy impair muscle performance has not been addressed in depth. The purpose of this study was to determine the extent of neuromuscular activation of the knee extensors and ankle dorsiflexors of 27 men infected with HIV receiving antiretroviral therapy and its relationship to muscle performance. The central activation ratio (CAR) was determined using superimposed electrical stimulation during maximum voluntary contractions. In addition to force and power measurements, muscle cross‐sectional area and composition was evaluated using computed tomography. Aerobic capacity was determined from treadmill exercise testing. Eleven of the subjects had an impaired ability to activate the knee extensors (CAR = 0.72 ± 0.12) that was associated with weakness and decreased specific force. The reduced central activation was not associated with muscle area, body composition, aerobic capacity, CD4 count, or medication regimen. Those individuals with low central activation had higher HIV‐1 viral loads and were more likely to have a history of AIDS‐defining illness. These results suggest the possibility of a different mechanism contributing to muscle impairment in the current treatment era that is associated with impairment of central motor function rather than atrophy. Further investigation is warranted in a larger, more diverse population before more definitive claims are made. Muscle Nerve, 2007
Fukutin‐related protein localizes to the Golgi apparatus and mutations lead to mislocalization in muscle in vivo
Authors: Keramaris‐Vrantsis Elizabeth , Lu Pei J. , Doran Timothy , Zillmer Allen , Ashar Jignya , Esapa Christopher T. , Benson Matthew A. , Blake Derek J. , Rosenfeld Jeffrey , Lu Qi L. 
Published: June 2007

AbstractMutations in the fukutin‐related protein gene (FKRP) are associated with a spectrum of diseases from mild limb‐girdle muscular dystrophy type 2I to severe congenital muscular dystrophy type 1C, muscle–eye–brain disease (MEB), and Walker–Warburg syndrome (WWS). The effect of mutations on the transportation of the mutant proteins may constitute the underlying mechanisms for the pathogenesis of these diseases. Here we examined the subcellular localization of mouse and human normal and mutant FKRP proteins in cells and in muscle in vivo. Both normal human and mouse FKRPs localize in part of the Golgi apparatus in muscle fibers. Mutations in the FKRP gene invariably altered the localization of the protein, leading to endoplasmic reticulum retention within cells and diminished Golgi localization in muscle fibers. Our results therefore suggest that an individual missense point mutation can confer at least two independent effects on the protein, causing (1) reduction or loss of the presumed glycosyltransferase activity directly and (2) mislocalization that could further alter the function of the protein. The complexity of the effect of individual missense point mutations may partly explain the wide variation of the FKRP‐related myopathies. Muscle Nerve, 2007
Efficient scheduling discipline for Hierarchical Diff‐EDF
Authors: Saleh Moutaz , Othman Zulaiha Ali 
Published: June 2007

AbstractPacket networks are currently enabling the integration of traffic with a wide range of characteristics that extend from video traffic with stringent quality of service (QoS) requirements to the best‐effort traffic requiring no guarantees. QoS guarantees can be provided in conventional packet networks by the use of proper packet‐scheduling algorithms. As a computer revolution, many scheduling algorithms have been proposed to provide different schemes of QoS guarantees, with Earliest Deadline First (EDF) as the most popular one. With EDF scheduling, all flows receive the same miss rate regardless of their traffic characteristics and deadlines. This makes the standard EDF algorithm unsuitable for situations in which the different flows have different miss rate requirements since in order to meet all miss rate requirements it is necessary to limit admissions so as to satisfy the flow with the most stringent miss rate requirements. In this paper, we propose a new priority assignment scheduling algorithm, Hierarchal Diff‐EDF (Differentiate Earliest Deadline First), which can meet the real‐time needs of these applications while continuing to provide best‐effort service to non‐real time traffic. The Hierarchal Diff‐EDF features a feedback control mechanism that detects overload conditions and modifies packet priority assignments accordingly. Copyright © 2007 John Wiley & Sons, Ltd.
Epoxy phosphonate crosslinkers for providing flame resistance to cotton textiles
Authors: Chang SeChin , Sachinvala Navzer (Nozar) D. , Sawhney Paul , Parikh D. V. , Jarrett William , Grimm Casey 
Published: June 2007

AbstractTwo new monomers (2‐methyl‐oxiranylmethyl)‐phosphonic acid dimethyl ester (3) and [2‐(dimethoxy‐phosphorylmethyl)‐oxyranylmethyl]‐phosphonic acid dimethyl ester (6) were prepared and used with dicyandiamide (7) and citric acid (8) to impart flame resistance to cotton plain weave, twill, and 80:20‐cotton/polyester fleece fabrics. Monomers 3 and 6 were prepared from methallyl chloride (1) and 3‐chloro‐2‐chloromethylpropene (4) respectively via a two‐step phosphorylation epoxidation sequence in 79.3 and 67.5% overall yields. 1H and 13C nuclear magnetic resonance (NMR) and gas chromatographic mass spectrometry (GCMS) data were used to confirm their structures. Decomposition of monomers 3 and 6 in nitrogen by thermogravimetric analysis (TGA) occurred at 110 and 220°C, respectively. The mixtures of 3:7:8 and 6:7:8 (in 2:1:1 ratio) exhibited peak‐curing temperatures by differential scanning calorimeter (DSC) at 125 and 150°C and the temperatures were deemed suitable for curing treated fabrics without marring them. Flame‐retardant treatments were applied by the pad‐dry‐cure methods. All untreated fabrics showed limiting oxygen index (LOI) values of about 18% oxygen in nitrogen. For formulations with monomer 3, LOI values for the three types of treated fabrics were greater than 25.5% when add‐on values for the formulation were 17.4, 12.7, and 21.1%. For formulations comprising monomer 6, LOI values were greater than 28.6% when add‐on values for the formulation were 18.3, 13.1, and 16.7%. With the formulation comprising monomer 3, the three fabrics passed the vertical flame test when add‐on values were 21.6, 12.7, and 23.5%, respectively; and with the formulation comprising monomer 6, they passed the vertical flame test when add‐on values were 13.8, 8.4, and 18.0%. In all cases char lengths of fabrics that passed the vertical flame test were less than 50% of original length and after‐flame time was 0 sec and after‐glow time was less than 2 sec. Published in 2007 by John Wiley & Sons, Ltd.
Fabrication of optical waveguide devices using gas‐assisted UV micro/nanoimprinting with soft mold
Authors: Weng Y.‐J. , Weng Y.‐C. , Yang S.‐Y. , Wang L. A. 
Published: June 2007

AbstractWavelength limitation and diffraction of light are the bottlenecks encountered in the production of structures by conventional lithography. Nano‐imprinting has been a potential process for mass production of nanometer structures at low cost. This paper reports an innovative process to replicate the ridge‐shaped microstructures on the silicon mold onto the photoresist using gas‐assisted pressing mechanism and soft mold. The microstructures on the silicon mold are replicated unto PC films. The soft mold is obtained by casting the PDMS with the PC film as templates, PDMS mold and UV‐curable photoresist are brought into contact, and are pressurized by gas and cured by UV‐light at the same time. After curing, structures for optical wave guilding can be obtained, In this process, through the control of gas pressure, the residual layer of the ridge‐shaped component for light guilding can eliminated. Etching is no longer needed to get rid of the residual layer. This process is effective for mass production for replication of microstructures at low cost. Copyright © 2007 John Wiley & Sons, Ltd.
The structure of submicron polyethylene/silica composite particles
Authors: Makarov Carina , Khalfin Rafail L. , Makarov Vadim , Cohen Yachin , Sertchook Hanan , Elimelech Hila , Avnir David 
Published: June 2007

AbstractA novel method for a one‐step preparation of silica/low‐density polyethylene (LDPE) composite particles has been developed recently, based on performing sol–gel polycondensation within an emulsion of LDPE dissolved in xylene and tetraethyl othosilicate which is stabilized by poly (ethylene‐block‐ethylene glycol) block copolymer surfactant (PBP), all dispersed in a basic ethanolic medium. The particle dimensions are in the sub‐micron range with diameters of 200–500 nm. Small‐angle X‐ray scattering (SAXS) measurements with contrast variation, in conjunction with other characterization methods, provide information on the inner structure of the nanoparticle's composition and inhomogeneity, which has a characteristic dimension of about 7 nm. Increase in the PBP amount and the presence of LDPE result in decrease in volume fraction of voids. The surface of the particles is heavily coated with the organic material. The crystallinity and melting behavior of LDPE is unaffected by its confinement to the particles. Copyright © 2007 John Wiley & Sons, Ltd.
Polymeric materials for fuel cells: concise review of recent studies
Authors: Jagur‐Grodzinski Joseph 
Published: June 2007

AbstractPolymeric materials find applications in almost all types of fuel cells (FCs). For example, microstructural optimization of materials by poly(methyl methacrylate) microspheres in solid oxide fuel cells (SOFCs) or as the conductive binders for the preparation of carbon electrodes for the phosphoric acid fuel cells (PAFCs). However, these applications are only marginal and not intrinsically essential to the functioning of these types of fuel cells, and will not be discussed in this review. On the other hand, ion exchange polymers used for the preparation of the ion exchange membranes, separating anode and cathode compartment of proton exchange membrane fuel cells (PEMFCs), anion exchange membrane fuel cells (AEMFCs), and direct methanol fuel cells (DMFCs) are one of their major components, and investigations of them, conducted during the last two years, are discussed in the present review. The same is true for a few polymers used for complexation of enzymes and their attachment to electrodes of biofuel cells (BFCs). Copyright © 2007 John Wiley & Sons, Ltd.
Polymer modified biomass of baker's yeast for treating simulated wastewater containing nickel and lead
Authors: Tong Mi , Yu Junxia , Sun Xiaomei , Li Buhai 
Published: June 2007

AbstractBaker's yeast was cross‐linked by glutaraldehyde and then modified by grafting with poly(amic acid), which was prepared via reaction of pyromellitic dianhydride (PMDA) and arginine at 50°C. The morphology of the pristine, cross‐linked, and modified biomass was observed by microscope. The presence of poly(amic acid) on the biomass surface was verified by X‐ray photoelectron spectroscopy (XPS) analyses. Due to the high density of the functional groups on the modified biomass surface, the metal adsorption capacity for nickel and lead increased significantly, especially when the carboxylic acid groups were converted into carboxylate ions using NaOH. The adsorption process for nickel and lead adsorption followed the pseudo‐second‐order kinetics. The metal adsorption data were fitted with the Langmuir and Freundlich isotherms with the former having a better fit. Using the Langmuir adsorption isotherm, the maximum uptakes for nickel and lead were found to be 0.848 and 0.980 mmol g−1 respectively which were about 15 and 11 times higher than the prisitine biomass. In the simulated wastewater containing 0.400 mmol l−1 of Ni2+ and Pb2+, the metal adsorption capacity of Ni2+ and Pb2+ reached 0.365 mmol l−1 and 0.390 mmol l−1, respectively. The metal ions loaded biomass was regenerated using Ethylene Diamine Tetraacetic Acid (EDTA) solution and used repeatedly over four cycles with little loss of uptake capacity. Copyright © 2007 John Wiley & Sons, Ltd.
Sickle cell disease caused by Hb S/Québec‐CHORI: Treatment with hydroxyurea and response
Authors: Tubman Venée N. , Bennett Carolyn M. , Luo Hong‐yuan , Chui David H.K. , Heeney Matthew M. 
Published: June 2007

AbstractSickle hemoglobin (Hb S; β Glu6Val) is due to an A>T transversion in codon 6 of the β‐globin gene. Other variant hemoglobins mimic Hb A, S, or C on newborn screening and clinical laboratory diagnostic tools, thus making their correct identification potentially difficult. Sickling disorders can result in individuals who are compound heterozygous for β‐globin mutations (e.g., Hb SC, HbSOArab). The authors report a second case of HbS/Québec‐CHORI, a severe compound heterozygous sickling disorder and their experience managing this patient with hydroxyurea. Pediatr Blood Cancer 2007;49:207–210. © 2007 Wiley‐Liss, Inc.
High‐grade astrocytoma in very young children
Authors: Sanders Robert P. , Kocak Mehmet , Burger Peter C. , Merchant Thomas E. , Gajjar Amar , Broniscer Alberto 
Published: June 2007

AbstractBackgroundHigh‐grade astrocytomas are rare in young children, but have been reported to have a better prognosis than similar tumors in older patients.ProcedureWe retrospectively reviewed the clinical characteristics, survival, and long‐term sequelae for patients younger than 3 years old with high‐grade astrocytoma, treated at a single institution between 1984 and 2005.ResultsSixteen patients were included. Histology included anaplastic astrocytoma (n = 9), glioblastoma multiforme (n = 5), and malignant glioma (n = 2). All patients underwent biopsy or resection, followed by chemotherapy. Six patients received scheduled irradiation and six were irradiated at the time of disease progression. Ten patients are alive at a median follow‐up of 11.6 years (range, 1.7–21.6 years). 5‐year overall survival (OS) was 66.3% (SE 12.2%), and 5‐year event‐free survival (EFS) was 28.6% (SE 12.1%). Age at diagnosis was a significant predictor of the hazard of death in a Cox model (HR 2.871, 95%CI 1.015–8.123). Gender and histology did not predict OS or EFS. Trends toward improved OS were detected for patients with hemispheric tumors and those undergoing complete resection. All evaluable survivors (n = 9) had some neurocognitive impairment, with estimated overall cognitive ability ranging from significantly delayed to average; all survivors attending school (n = 5) performed below grade level on achievement testing. Seven of nine evaluable survivors had endocrine dysfunction.ConclusionsYoung children with high‐grade astrocytoma have better long‐term overall survival than older patients, but recurrence is common, and most children require irradiation. Long‐term complications are frequent and often severe. Pediatr Blood Cancer 2007;49:888–893. © 2007 Wiley‐Liss, Inc.
Retinoic acid induced downregulation of MYCN is not mediated through changes in Sp1/Sp3
Authors: Kanemaru Kelli K. , Tuthill Matthew C. , Takeuchi Kenneth K. , Sidell Neil , Wada Randal K. 
Published: June 2007

AbstractBackgroundUse of retinoic acid (RA) has become the standard of care in the treatment of high risk neuroblastoma (NB). In vitro, RA induces growth arrest and differentiation, an effect that likely underlies its activity in the clinical setting. An important event in differentiation is the transcriptional downregulation of the MYCN oncogene, which is frequently activated in aggressive tumors. While it is known that Sp1/Sp3 and E2F are necessary to drive basal MYCN expression, the mechanism for its downregulation by RA remains enigmatic. Changes in E2F binding have been reported, however these occurred after the actual transcriptional response. Here, post‐translational modifications of Sp proteins were examined as an alternate mechanism of RA‐mediated promoter regulation.ProcedureWestern blot was used to evaluate steady state levels of nuclear/cytoplasmic Sp1/Sp3. Promoter binding and DNA conformation were determined by gel shift, circular permutation, and chromatin immunoprecipitation assays. Immunoprecipitation/western and 32P‐phosphoamino analyses were used to detect glycosylation, acetylation, sumoylation, and phosphorylation.ResultsRA did not affect the cellular level of Sp1/Sp3 proteins, their nuclear/cytoplasmic distribution, ability to bind the MYCN promoter, degree of Sp‐induced DNA bending, or post‐translational modifications.ConclusionsMYCN RA response is not mediated solely though the region controlling basal activity. RA may be exerting its effects via multiple non‐adjacent regulatory regions, potentially including basal motifs, either within the MYCN promoter or distally, on the same or even different chromosomes. Such cooperative trans‐type DNA–protein interactions could explain the inaccessibility of this mechanism to the locus‐specific approaches employed up to this point. Pediatr Blood Cancer 2008;50:806–811. © 2007 Wiley‐Liss, Inc.