bluuebunny/crossref_metadata_2025_split huggingface dataset:
Masses of the Elbow and Forearm
Authors: Crain Jana , Ho Charles 
Published: January 2008

AbstractThis unit presents protocols for MR imaging of masess of the elbow using T1‐ and T2‐weighted sequences. An alternative method using post‐contrast images is also provided, which may help to differentiate cystic or necrotic lesions from solid masses by defining a nodular or peripheral enhancing component in a cystic lesion versus more diffuse enhancement in a solid mass.
Magnetic Moment of a Spin, Its Equation of Motion, and Precession
Authors: Cheng Yu‐Chung Norman , Haacke E. Mark 
Published: January 2008

AbstractThis unit discusses the basic spin properties of the proton. The motion of a spin in an magnetic field that give rise to magnetic moment, is also discussed. The key to grasping much of MRI lies in understanding the concept of precession. Famous Bloch equation that basically leads to the description of the precession of a spin in the presence of an external magnetic field is also explained.
Genotyping Using the TaqMan Assay
Authors: Hui Lester , DelMonte Terrye , Ranade Koustubh 
Published: January 2008

AbstractThe 5′‐nuclease allelic discrimination assay, or TaqMan assay, is a PCR‐based assay for genotyping single nucleotide polymorphisms (SNPs). The region flanking the SNP is amplified in the presence of two allele‐specific fluorescent probes. The probes do not fluoresce in solution because of a quencher at the 3′ end. The presence of two probes allows the detection of both alleles in a single tube. Moreover, because probes are included in the PCR, genotypes are determined without any post‐PCR processing, a feature that is unavailable with most other genotyping methods. This unit describes probe and primer design and PCR conditions. Curr. Protoc. Hum. Genet. 56:2.10.1‐2.10.8. © 2008 by John Wiley & Sons, Inc.
Selection of a Platform for Mutation Detection
Authors: Joshi Victoria A. , Mancini‐DiNardo Debora , Funke Birgit H. 
Published: January 2008

AbstractNew mutation detection technologies must keep pace by becoming more cost‐effective while offering improved technical sensitivity and higher throughput capacity. In recent years, the number of mutation detection platforms available to the clinical researcher has grown to a point where it is difficult to keep track of all available options as well as their benefits and pitfalls. This unit provides an entry point for a variety of researchers who wish to analyze samples for known or novel mutations and need to determine which platform is most suited for their particular needs. A practical guide is provided in this unit, including a brief overview, information on assay parameters, design and cost considerations, as well as platform flexibility and scalability of the assay. Although the focus here is on applications involving human disease, many of these platforms can be easily adapted to the study of other organisms. Curr. Protoc. Hum. Genet. 56:7.15.1‐7.15.30. © 2008 by John Wiley & Sons, Inc.
Methods and Applications of Laser‐Enabled Analysis and Processing (LEAP)
Authors: Lin Nan , Cresswell Jennifer R. , Richardson Genova A. , Gerber Mark A. , Kayser Kevin J. 
Published: January 2008

AbstractThe LEAP (Laser‐Enabled Analysis and Processing) platform combines in situ imaging with laser manipulation to efficiently identify, purify, and monitor expansion of high secreting clones. It also allows for rapid analysis of cell population heterogeneity. This unit describes the LEAP instrumentation as well as basic and alternate protocols of the major applications in recombinant human or humanized IgG expression. The protocols include fluorescent cell counting, secreted recombinant IgG capture and detection, and IgG‐secreting clone selection by laser processing. Curr. Protocol. Cytom. 43:2.14.1‐2.14.27. © 2008 by John Wiley & Sons, Inc.
Directed Differentiation of Human Embryonic Stem Cells as Spin Embryoid Bodies and a Description of the Hematopoietic Blast Colony Forming Assay
Authors: Ng Elizabeth S. , Davis Richard P. , Hatzistavrou Tanya , Stanley Edouard G. , Elefanty Andrew G. 
Published: January 2008

AbstractThis unit describes a protocol for the differentiation of human embryonic stem cells (hESCs). To generate spin embryoid bodies (EBs), known numbers of hESCs are deposited into low‐attachment, round‐bottomed 96‐well plates in a serum‐free medium supplemented with growth factors. The cells are then aggregated by centrifugation, initiating formation of EBs of uniform size. The spin EBs generated using this technique differentiate efficiently and synchronously along the lineages preferentially induced by the combinations of growth factors to which the cells are exposed. The 96‐well format permits an assessment of the effects of different combinations of growth factors in the same experiment, facilitating the optimization of differentiation conditions for any given cell type. Up to 40 plates can be set up within a couple of hours by one experimenter, and aliquots of the differentiating EBs can be harvested at intervals and subjected to analyses using a variety of techniques. Curr. Protoc. Stem Cell Biol. 4:1D.3.1‐1D.3.23. © 2008 by John Wiley & Sons, Inc.
Primary Neuron/Astrocyte Co‐Culture on Polyelectrolyte Multilayer Films: A Template for Studying Astrocyte‐Mediated Oxidative Stress in Neurons
Authors: Kidambi S. , Lee I. , Chan C. 
Published: January 2008

AbstractWe engineered patterned co‐cultures of primary neurons and astrocytes on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ligands to study the oxidative stress mediated by astrocytes on neuronal cells. A number of studies have explored engineering co‐culture of neurons and astrocytes predominantly using cell lines rather than primary cells owing to the difficulties involved in attaching primary cells onto synthetic surfaces. To our knowledge this is the first demonstration of patterned co‐culture of primary neurons and astrocytes for studying neuronal metabolism. In our study, we used synthetic polymers, namely poly(diallyldimethylammoniumchloride) (PDAC) and sulfonated poly(styrene) (SPS) as the polycation and polyanion, respectively, to build the multilayers. Primary neurons attached and spread preferentially on SPS surfaces, while primary astrocytes attached to both SPS and PDAC surfaces. SPS patterns were formed on PEM surfaces, either by microcontact printing SPS onto PDAC surfaces or vice‐versa, to obtain patterns of primary neurons and patterned co‐cultures of primary neurons and astrocytes. We further used the patterned co‐culture system to study the neuronal response to elevated levels of free fatty acids as compared to the response in separated monoculture by measuring the level of reactive oxygen species (ROS; a widely accepted marker of oxidative stress). The elevation in the ROS levels was observed to occur earlier in the patterned co‐culture system than in the separated monoculture system. The results suggest that this technique may provide a useful tool for engineering neuronal co‐culture systems, that may more accurately capture neuronal function and metabolism, and thus could be used to obtain valuable insights into neuronal cell function and perhaps even the pathogenesis of neurodegenerative diseases.
Formulation of Superparamagnetic Iron Oxides by Nanoparticles of Biodegradable Polymers for Magnetic Resonance Imaging
Authors: Wang Y. , Ng Y. W. , Chen Y. , Shuter B. , Yi J. , Ding J. , Wang S.‐c. , Feng S. S. 
Published: January 2008

AbstractA system of poly(lactide‐co‐glycolide)‐methoxy poly(ethylene glycol) (PLGA‐mPEG) nanoparticles is developed to formulate superparamagnetic iron oxides (IOs) for magnetic resonance imaging (MRI). This system improves the imaging effects, increases the half‐life of the IOs in circulation, and reduces their side effects. The IO‐loaded PLGA‐mPEG nanoparticles were prepared by a modified water‐in‐oil‐in‐water double‐emulsion technique. Their physicochemical and superparamagnetic properties were characterized by various techniques. In vitro IO release kinetics from the nanoparticles and stability of the IO‐loaded polymeric nanoparticles were also investigated. In vitro and ex vivo MRI of the IOs formulated in the PLGA‐mPEG nanoparticles show that the saturation magnetization and ther2,r2* relaxivities are enhanced, and the contrast effects are improved in comparison with commercial IOs (Resovist). It is proven that the enhanced superparamagnetic properties are caused by the polymeric nanoparticle formulation but not by the polymeric material itself. Moreover, the PLGA‐mPEG nanoparticle formulation achieves 36.9 and 35.6 % less cytotoxicity in comparison with the IOs (Resovist) after 48 h incubation at the same 20 and 50 μg mL–1Fe concentration, respectively. This research implies that formulation of IOs by nanoparticles of PLGA‐mPEG copolymer or other biodegradable polymers could be promising for more effective and sustainable MRI with reduced side effects, which, with targeting probes conjugated to the nanoparticle surface, can be further used to promote cellular and molecular MRI.
Exploitation of Diatom Frustules for Nanotechnology: Tethering Active Biomolecules
Authors: Townley H. E. , Parker A. R. , White‐Cooper H. 
Published: January 2008

AbstractDiatoms are single‐celled microalgae with rigid walls (frustules) composed of amorphous silica. The intricate 3D microstructure of diatoms results in a high surface area formed by myriad pores and channels. The combination of the silica chemistry of the frustule coupled with the high surface area makes it particularly suitable for applications such as microscale total analysis systems. Here it is demonstrated that the diatom frustule can be chemically modified for the attachment of antibodies, and that the attached antibodies retain biological activity. These modified structures have potential applications in antibody arrays and may have use in techniques such as immunoprecipitation. These silica structures are produced in diatoms using only light and minimal nutrients and, therefore, generate an exceptionally cheap and renewable material.
Red‐Light‐Emitting Iridium Complexes with Hole‐Transporting 9‐Arylcarbazole Moieties for Electrophosphorescence Efficiency/Color Purity Trade‐off Optimization
Authors: Ho C.‐L. , Wong W.‐Y. , Gao Z.‐Q. , Chen C.‐H. , Cheah K.‐W. , Yao B. , Xie Z.‐Y. , Wang Q. , Ma D.‐G. , Wang L.‐X. , Yu X.‐M. , Kwok H.‐S. , Lin Z.‐Y. 
Published: January 2008

AbstractThe synthesis, structures, photophysics, electrochemistry and electrophosphorescent properties of new red phosphorescent cyclometalated iridium(III) isoquinoline complexes, bearing 9‐arylcarbazolyl chromophores, are reported. The functional properties of these red phosphors correlate well with the results of density functional theory calculations. The highest occupied molecular orbital levels of these complexes are raised by the integration of a carbazole unit to the iridium isoquinoline core so that the hole‐transporting ability is improved in the resulting complexes relative to those with 1‐phenylisoquinoline ligands. All of the complexes are highly thermally stable and emit an intense red light at room temperature with relatively short lifetimes that are beneficial for highly efficient organic light‐emitting diodes (OLEDs). Saturated red OLEDs, fabricated using these dyes as the phosphorescent dopants both as vacuum‐evaporated and spin‐coated emissive layers, have been achieved in a multilayer configuration with outstanding red color purity at Commission International de L'Éclairage (CIE) coordinates of (0.67,0.33) to (0.68,0.32). Some of the devices can show very high efficiencies with a maximum external quantum efficiency of up to 12 % photons per electron. The excellent performance of these red emitters indicates the advantage of the carbazole module in the ligand framework; demonstrated by an improved hole‐transporting ability that facilitates exciton transport. These materials could thus provide a new avenue for the rational design of heavy‐metal electrophosphors that reveal a superior device efficiency/color purity trade‐off necessary for pure red‐light generation.
Silicone–Poly(hexylthiophene) Blends as Elastomers with Enhanced Electromechanical Transduction Properties
Authors: Carpi F. , Gallone G. , Galantini F. , De Rossi D. 
Published: January 2008

AbstractDielectric elastomers are progressively emerging as one of the best‐performing classes of electroactive polymers for electromechanical transduction. They are used for actuation devices driven by the so‐called Maxwell stress effect. At present, the need for high‐driving electric fields limits the use of these transduction materials in some areas of potential application, especially in the case of biomedical disciplines. A reduction of the driving fields may be achieved with new elastomers offering intrinsically superior electromechanical properties. So far, most attempts in this direction have been focused on the development of composites between elastomer matrixes and high‐permittivity ceramic fillers, yielding limited results. In this work, a different approach was adopted for increasing the electromechanical response of a common type of dielectric elastomer. The technique consisted in blending, rather than loading, the elastomer (poly(dimethylsiloxane)) with a highly polarizable conjugated polymer (undoped poly(3‐hexylthiophene)). The resulting material was characterised by dielectric spectroscopy, scanning electron microscopy, tensile mechanical analysis, and electromechanical transduction tests. Very low percentages (1–6 wt %) of poly(3‐hexylthiophene) yielded both an increase of the relative dielectric permittivity and an unexpected reduction of the tensile elastic modulus. Both these factors synergetically contributed to a remarkable increase of the electromechanical response, which reached a maximum at 1 wt % content of conjugated polymer. Estimations based on a simple linear model were compared with the experimental electromechanical data and a good agreement was found up to 1 wt %. This approach may lead to the development of new types of materials suitable for several types of applications requiring elastomers with improved electromechanical properties.
The 2,2,6,6‐Tetramethyl‐1‐piperidinyloxy Radical: An Efficient, Iodine‐ Free Redox Mediator for Dye‐Sensitized Solar Cells
Authors: Zhang Z. , Chen P. , Murakami T. N. , Zakeeruddin S. M. , Grätzel M. 
Published: January 2008

AbstractA promising redox system, offering an alternative to the widely used iodide/triiodide couple, based on the stable organic radical 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) has been employed in dye‐sensitized solar cells. The photovoltaic performance of this new redox couple has been evaluated by employing nanocrystalline TiO2 films with different thickness. Judicious selections of a 5.0 μm photoanode made from TiO2 mesoscopic particles and an organic sensitizer with a high molar extinction coefficient yield an overall solar‐to‐electric power conversion efficiency of 5.4 % under AM 1.5 illumination at 100 mW cm–2, which is unprecedented for an iodine‐free mediator system.
Inside Front Cover: Unprecedented Dual Alignment Mode and Freedericksz Transition in Planar Nematic Liquid Crystal Cells Doped with Gold Nanoclusters (Adv. Funct. Mater. 2/2008)
Authors: Qi H. , Kinkead B. , Hegmann T. 
Published: January 2008

AbstractOn p. 212, Torsten Hegmann and co‐workers describe nematic liquid crystals (N‐LCs) confined in planar liquid crystal cells after doping with small quantities of gold nanoclusters. These give rise to a dual alignment mode and electro‐optic response (Freedericksz transition). By fine‐tuning of experimental conditions, N‐LCs doped with gold nanoclusters can be electrically reoriented and aligned either like N‐LCs with a positive dielectric anisotropy (used in twisted nematic displays) in a planar cell or alternatively as N‐LCs with a negative dielectric anisotropy (used in large LCD TVs based on the vertical alignment mode).We demonstrate that alkylthiol‐capped gold nanoclusters doped into nematic liquid crystals (N‐LCs) with positive dielectric anisotropy give rise to an unprecedented dual alignment mode and electro‐optical response, which has a potential impact on current liquid crystal (LC) display technologies and N‐LC optical‐biosensor design. By fine‐tuning experimental conditions (temperature, electric field, and alignment), N‐LCs doped with gold nanoclusters can be aligned and electrically reoriented either like N‐LCs with a positive dielectric anisotropy in a planar cell or, alternatively, as N‐LCs with a negative dielectric anisotropy in a homeotropic cell, both at lower threshold voltages than the pure N‐LC.
Organic Electronics: The Ions Have It
Authors: Leger J. M. 
Published: January 2008

AbstractOrganic electronics research has focused primarily on flexible, inexpensive versions of traditional semiconductor technologies. Although mixed ionic/electronic conduction in conjugated organic materials introduces exciting functionality, the understanding of the fundamental processes that take place is still in its infancy. In this Research News article, the advantages, applications, and basic research needs that relate to the incorporation of ionic carriers in organic electronic materials and devices are discussed and placed in the broader context of the field.
Managing risk through a flexible recipe framework
Authors: Ferrer‐Nadal Sergio , Puigjaner Luis , Guillén‐Gosálbez Gonzalo 
Published: January 2008

AbstractA novel approach is proposed that exploits the use of a flexible recipe framework as a better way to handle the risk associated with the scheduling under uncertainty of batch chemical plants. The proposed solution strategy relies on a novel two‐stage stochastic formulation that explicitly includes the trade‐off between risk and profit at the decision‐making level. The model uses a continuous‐time domain representation and the generalized notion of precedence. Management of risk is explicitly addressed by including a control measure (i.e., the profit in the worst scenario), as an additional objective to be considered, thus, leading to a multiobjective optimization problem. To overcome the numerical difficulties associated with such mathematical formulation, a decomposition strategy based on the sample average approximation (SAA) is introduced. The main advantages of this approach are illustrated through a case study, in which a set of solutions appealing to decision makers with different attitudes toward risk are obtained. The potential benefits of the proposed flexible recipe framework as a way of managing the risk associated with the plant operation under demand uncertainty are highlighted through comparison with the conventional approach that considers nominal operating conditions. Numerical results corroborate the advantages of exploiting the capabilities of the proposed flexible recipe framework for risk management purposes. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Varying the blending protocol to control the morphology of model compatibilized polymer blends
Authors: Martin Jeffrey D. , Velankar Sachin S. 
Published: January 2008

AbstractThe structure of an oil/water emulsion is known to depend on its preparation method. Here, we test whether the preparation protocol can be used to control the morphology of “model” blends of immiscible polymers compatibilized by a diblock copolymer. Two preparation protocols were tested. In the “double blending” protocol, a droplet‐matrix blend was blended with additional drop‐phase fluid. As in oil/water emulsions, this yielded a drop‐within‐drop “double emulsion” morphology. Coalescence suppression due to compatibilizer was found crucial to double emulsion stability. The rheology of the double emulsion was qualitatively similar to that of a simple droplet‐matrix blend, but with an effectively higher drop volume fraction. In the “multistep concentration” protocol, the drop phase was added gradually (rather than all‐at‐once) to the matrix phase. While this protocol can realize a high‐dispersed phase emulsion in oil/water systems, in this case, phase inversion occurred when the drop volume fraction exceeded 0.5. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Memory enhancement induced by hypothalamic/fornix deep brain stimulation
Authors: Hamani Clement , McAndrews Mary Pat , Cohn Melanie , Oh Michael , Zumsteg Dominik , Shapiro Colin M. , Wennberg Richard A. , Lozano Andres M. 
Published: January 2008

AbstractBilateral hypothalamic deep brain stimulation was performed to treat a patient with morbid obesity. We observed, quite unexpectedly, that stimulation evoked detailed autobiographical memories. Associative memory tasks conducted in a double‐blinded “on” versus “off” manner demonstrated that stimulation increased recollection but not familiarity‐based recognition, indicating a functional engagement of the hippocampus. Electroencephalographic source localization showed that hypothalamic deep brain stimulation drove activity in mesial temporal lobe structures. This shows that hypothalamic stimulation in this patient modulates limbic activity and improves certain memory functions. Ann Neurol 2008;63:119–123
The olfactory vector hypothesis of neurodegenerative disease: Is it viable?
Authors: Doty Richard L. 
Published: January 2008

AbstractEnvironmental agents, including viruses, prions, and toxins, have been implicated in the cause of a number of neurodegenerative diseases, most notably Alzheimer's and Parkinson's diseases. The presence of smell loss and the pathological involvement of the olfactory pathways in the formative stages of Alzheimer's and Parkinson's diseases, together with evidence that xenobiotics, some epidemiologically linked to these diseases, can readily enter the brain via the olfactory mucosa, have led to the hypothesis that Alzheimer's and Parkinson's diseases may be caused or catalyzed by agents that enter the brain via this route. Evidence for and against this concept, the “olfactory vector hypothesis,” is addressed in this review. Ann Neurol 2008;63:7–15
Synthesis and characterization of poly(acryloxyethyl‐trimethylammonium chloride‐co‐2‐hydroxyethyl methacrylate): A study of its interaction with sodium alginate
Authors: Valdés Oscar , Monett Dagmar , Agüero Lissette , Zaldívar Dionisio , Alexandrova Larissa , Katime Issa 
Published: January 2008

AbstractPoly(acryloxyethyl‐trimethylammonium chloride‐co‐2‐hydroxyethyl methacrylate) [poly(Q‐co‐H)] was prepared by free radical polymerization in aqueous solution at 60°C using potassium persulfate as initiator. Spectroscopic characterization confirmed the formation of poly(Q‐co‐H) and the molar fractions of acryloxyethyl‐trimethylammonium chloride monomer units incorporated in the copolymers were determined by potenciometric titrations. The monomer reactivity ratios for Q and H are found to be rQ = 0.04 ± 0.01 and rH = 3.22 ± 0.84 using Fineman–Röss method and rQ = 0.06 and rH = 3.61 using Genetic Algorithms method. Finally we studied reaction between poly(Q‐co‐H) and sodium alginate by conductimetric measurement. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008