bluuebunny/crossref_metadata_2025_split huggingface dataset:
Whole‐Cell Recording In Vivo
Authors: R. DeWeese Michael 
Published: January 2007

AbstractIn vivo whole‐cell patch‐clamp recording provides a means for measuring membrane currents and potentials from individual cells in the intact animal. Patch‐clamp methods have largely been developed in vitro. This body of work has contributed enormously to the understanding of many important phenomena in excitable cells—including synaptic plasticity in the mammalian central nervous system, and the behavior of individual protein channels. In recent years, an increasing number of groups have applied whole‐cell recording techniques in the intact animal. Such in vivo studies offer the tantalizing possibility of uncovering the underlying principles and mechanisms of neural interactions within the natural context of fully intact biological networks. This unit focuses on strategies for overcoming the specific technical challenges posed by in vivo whole‐cell recording. A straightforward procedure is described for obtaining whole‐cell records from the cortex of the anesthetized rat; this procedure has also been applied successfully to awake animals and other rodent species with minor modifications.
Isolation of Phosphopeptides by Immobilized Metal Ion Affinity Chromatography
Authors: Nühse Thomas , Yu Kebing , Salomon Arthur 
Published: January 2007

AbstractThe identification of protein phosphorylation sites from cell‐derived proteins is crucial to the understanding of signal transduction pathways. While determining the modified sites on individual proteins can present a significant challenge, recent progress in the rapid, large‐scale identification of phosphopeptides from complex protein mixtures by combinations of affinity chromatography and mass spectrometry provides a powerful tool to decipher the phosphoproteome. A set of protocols is described for sample preparation, fractionation, immobilized metal ion affinity chromatography (IMAC), and mass spectrometric analysis of phosphorylation sites. Parts of the protocols can be combined in different ways to adapt to sample amounts, complexity, and available equipment. Up to thousands of unique phosphopeptides can be sequenced from a single sample in a day, revealing a unique snapshot of global cellular phosphorylation sites on proteins and facilitating in‐depth study of the identified phosphoproteins.
Human Artificial Chromosome Assembly by Transposon‐Based Retrofitting of Genomic BACs with Synthetic Alpha‐Satellite Arrays
Authors: Basu Joydeep , Willard Huntington F. , Stromberg Gregory 
Published: January 2007

AbstractThe development of methodologies for the rapid assembly of synthetic alpha‐satellite arrays recapitulating the higher‐order periodic organization of native human centromeres permits the systematic investigation of the significance of primary sequence and sequence organization in centromere function. Synthetic arrays with defined mutations affecting sequence and/or organization may be evaluated in a de novo human artificial chromosome assay. This unit describes strategies for the assembly of custom built alpha‐satellite arrays containing any desired mutation as well as strategies for the construction and manipulation of alpha satellite–based transposons. Transposons permit the rapid and reliable retrofitting of any genomic bacterial artificial chromosome (BAC) with synthetic alpha‐satellite arrays and other functional components, thereby facilitating conversion into BAC‐based human artificial chromosome vectors. These techniques permit identification and optimization of the critical parameters underlying the unique ability of alpha‐satellite DNA to facilitate de novo centromere assembly, and they will establish the foundation for the next generation of human artificial chromosome vectors.
Production of Vesicular Stomatitis Virus G Glycoprotein (VSV‐G) Pseudotyped Retroviral Vectors
Authors: Lo Hsin‐Lung , Yee Jiing‐Kuan 
Published: January 2007

AbstractRetrovirus pseudotype is defined as the genome of one retrovirus encapsidated by the envelope protein of a second virus. The host range of the pseudotype is that of the virus donating the envelope protein. Two procedures that use 293GP cells, which are derived from human kidney 293 cells, are described here. The first is based on the high transient transfection efficiency of 293 cells. The retroviral construct and an expression plasmid for VSV‐G are co‐transfected into 293GP cells that stably express MLV gag and pol proteins. Transiently generated virus is then harvested during consecutive days following DNA transfection. The second procedure involves stable 293GP cell lines containing the VSV‐G gene under the control of a promoter whose activity is regulated by tetracycline. Cell lines containing the retroviral vector of interest are established under noninduced conditions. Infectious virus can be harvested following the induction of VSV‐G expression in these cell lines.
Flow Cytometry of the Side Population (SP)
Authors: Petriz Jordi 
Published: January 2007

AbstractThe side population (SP) has become an important hallmark for the definition of the stem‐cell compartment, especially for the detection of stem cells and for their physical isolation by fluorescence‐activated cell sorting (FACS). SP cells are CD34− and were discovered using ultraviolet excitation based on the efflux of Hoechst 33342 (Ho342). Although the method works as originally described, the protocol is difficult for most investigators to perform: first, because the ability to discriminate SP cells is based on the differential retention of Ho342 during a functional assay; second, because of the difficulties in setting the right experimental and acquisition conditions; and third, because analysis of the acquired data requires extensive expertise in flow cytometry to accurately detect the SP events. This unit is packed with helpful pointers to aid the user in obtaining the best possible results.
Validation of Tandem Mass Spectrometry Database Search Results Using DTASelect
Authors: Cociorva Daniel , L. Tabb David , Yates John R. 
Published: January 2007

AbstractDTASelect provides a means by which complex SEQUEST results can be filtered, organized, and viewed. A single sample may produce tens of thousands of tandem mass spectra. Manually perusing and selecting SEQUEST matches among such a mass of data carries a risk of inconsistency. DTASelect allows the user to set complex criteria for acceptance or rejection of individual spectrum results. It also features rules for dealing with multiple, identical peptide matches and for removing proteins that are insufficiently evidenced. It provides its sorted and filtered summary as HTML and text documents for easy review and also offers several auxiliary reports. DTASelect is a powerful tool for automatic analysis of complex mixture tandem mass spectrometry.
Does sex sell? The effect of sexual programme content on the recall of sexual and non‐sexual advertisements
Authors: Parker Ellie , Furnham Adrian 
Published: January 2007

AbstractThis study looked at the recall of sexual and non‐sexual television advertisements embedded within programmes, with or without, sexual content. It was predicted that there would be a detrimental effect of sexual programme content, and a beneficial effect of sexual advertisement content on ability to recall advertisements. Further, when programme and advertisement content were congruous (i.e. both sexual), this also would hinder recall. Participants aged between 18 and 31 were placed in one of four conditions and were shown either ‘Sex and the City’ (sexual programme) or ‘Malcolm in the Middle’ (non‐sexual programme) with sexual or non‐sexual advertisements embedded in each. Participants were then asked to recall advertisement details from the advertisements. The results indicated that there was a main effect of programme type, demonstrating that sexual programme content hindered recall of advertisements. However, there was no main effect of the type of advertisements seen (sexual or non‐sexual) on recall, nor was there a negative effect on recall when programme and advertisement content were congruous. An interaction between advertisements and sex of participants showed that males recalled sexual advertisements better and females recalled non‐sexual advertisements better. Limitations of the study are considered. Copyright © 2007 John Wiley & Sons, Ltd.
Chronic and temporary aggression causes hostile false memories for ambiguous information
Authors: Takarangi Melanie K. T. , Polaschek Devon L. L. , Hignett Andrew , Garry Maryanne 
Published: January 2007

AbstractChronic and temporarily aggressive people show a phenomenon known as the hostile attribution bias (HAB), in which access to hostile schemas leads them to interpret ambiguously hostile information in a hostile way. Can these people also be induced to remember unambiguously hostile, yet completely false information? To address this question, we investigated the effect of both chronic and temporary aggression on recall for a list containing words that could be interpreted as exemplars of either an aggressive (violence‐related) or non‐aggressive (kitchen‐related) category. Subjects were exposed to five consecutive lists of associated words including the ambiguous list, but half read a list of insult words immediately before presentation of the ambiguous list, while the other half read only emotionally neutral lists. When recalling the ambiguous list, aggressive subjects and subjects who were primed with insult words were more likely to report having seen unpresented aggressive words compared with their low aggressive and not primed counterparts. We discuss our findings in line with Anderson and Bushman's (2002) General Aggression Model (GAM). Copyright © 2007 John Wiley & Sons, Ltd.
Photoconductivity of a Low‐Bandgap Conjugated Polymer
Authors: Soci C. , Hwang I.‐W. , Moses D. , Zhu Z. , Waller D. , Gaudiana R. , Brabec C. J. , Heeger A. J. 
Published: January 2007

AbstractThe photoconductive properties of a novel low‐bandgap conjugated polymer, poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)], PCPDTBT, with an optical energy gap of Eg ∼ 1.5 eV, have been studied. The results of photoluminescence and photoconductivity measurements indicate efficient electron transfer from PCPDTBT to PCBM ([6,6]‐phenyl‐C61 butyric acid methyl ester, a fullerene derivative), where PCPDTBT acts as the electron donor and PCBM as the electron acceptor. Electron‐transfer facilitates charge separation and results in prolonged carrier lifetime, as observed by fast (t > 100 ps) transient photoconductivity measurements. The photoresponsivities of PCPDTBT and PCPDTBT:PCBM are comparable to those of poly(3‐hexylthiophene), P3HT, and P3HT:PCBM, respectively. Moreover, the spectral sensitivity of PCPDTBT:PCBM extends significantly deeper into the infrared, to 900 nm, than that of P3HT. The potential of PCPDTBT as a material for high‐efficiency polymer solar cells is discussed.
From Mesostructured Wurtzite ZnS‐Nanowire/Amine Nanocomposites to ZnS Nanowires Exhibiting Quantum Size Effects: A Mild‐Solution Chemistry Approach
Authors: Yao W.‐T. , Yu S.‐H. , Wu Q.‐S. 
Published: January 2007

AbstractMesostructured wurtzite ZnS‐nanowire‐bundle/amine nanocomposites displaying remarkable quantum size effects are synthesized by using a mild‐solution reaction using different amines, such as n‐butylamine, ethylamine, and tetraethylenepentamine, Zn(NO3)2·6 H2O, and CS(NH2)2 or Na2S·9 H2O as the precursors at temperatures ranging from room temperature to 180 °C. A possible mechanism for the shape‐controlled growth of ZnS nanowires and nanocomposites is proposed. Increasing the reaction temperature or dispersing the composite in acetic acid or NaOH solution leads to the destruction of the periodic structure and the formation of individual wurtzite nanowires and their aggregates. The nanowire/amine composites and individual wurtzite nanowires both display obvious quantum size effects. Strong band‐edge emission is observed for the wurtzite ZnS nanowires after removal of the amine. The optical properties of these nanocomposites and nanowires are strongly related to the preparation conditions and can be finely tuned. This technique provides a unique approach for fabricating highly oriented wurtzite ZnS semiconductor nanowires, and can potentially be extended to other semiconducting systems.
Ultrafast Spectroscopic Study of Photoinduced Electron Transfer in an Oligo(thienylenevinylene):Fullerene Composite
Authors: Hwang I.‐W. , Xu Q.‐H. , Soci C. , Chen B. , Jen A. K.‐Y. , Moses D. , Heeger A. J. 
Published: January 2007

AbstractPhotoinduced electron transfer and competing processes have been studied in composites of an oligo(thienylenevinylene) (OTV), comprised of ten dibuthoxyl‐thiophene units separated by vinylene units, and a C60 derivative, [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM), by using femtosecond transient absorption spectroscopy and sub‐nanosecond transient photoconductivity. We find that in OTV:PCBM the photoexcitations decay primarily via intrachain relaxation rather than photoinduced electron transfer from OTV to PCBM. The electron‐transfer process requires ca. 14 ps; larger by more than two orders of magnitude than the required time observed in conjugated‐polymer:C60 composites, and also larger than the 0.6 ps singlet‐state lifetime in OTV. These observations indicate that the quantum efficiency for photoinduced electron transfer in OTV:PCBM is less than 5 %.
Siliceous Unilamellar Vesicles and Foams by Using Block‐Copolymer Cooperative Vesicle Templating
Authors: Wang H. , Wang Y. , Zhou X. , Zhou L. , Tang J. , Lei J. , Yu C. 
Published: January 2007

AbstractBy employing commercial poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) block copolymers as templates in near‐neutral aqueous solutions in the absence of organic cosolvents, unilamellar siliceous vesicles and nanofoams with ultrahigh pore volumes (> 3 cm3 g–1) are successfully synthesized. At controlled pH, a tubular micelle → unilamellar vesicle → nanofoam structural transformation is observed by increasing the reaction temperature. It is proposed that the siliceous vesicles are synthesized via a co‐operative block‐copolymer vesicle templating approach, while the siliceous nanofoams are obtained by the fusion of vesicles at increased ionic strength. Compared to literature methods to synthesize siliceous vesicles and foams, our method is convenient, cheap, and produces a high yield. Siliceous nanofoams synthesized by using our approach show superior bioimmobilization capacity over other porous materials for biomolecules with large molecular weight.
Protein‐Mediated Synthesis of Uniform Superparamagnetic Magnetite Nanocrystals
Authors: Prozorov T. , Mallapragada S. K. , Narasimhan B. , Wang L. , Palo P. , Nilsen‐Hamilton M. , Williams T. J. , Bazylinski D. A. , Prozorov R. , Canfield P. C. 
Published: January 2007

AbstractMagnetite nanocrystals are synthesized in the presence of a recombinant Mms6 protein thought to be involved in the biomineralization of bacterial magnetite magnetosomes, the mammalian iron‐storage protein, ferritin, and two proteins not known to bind iron, lipocalin (Lcn2) and bovine serum albumin (BSA). To mimic the conditions at which magnetite nanocrystals are formed in magnetotactic bacteria, magnetite synthesis is performed in a polymeric gel to slow down the diffusion rates of the reagents. Recombinant Mms6 facilitates formation of ca. 30 nm single‐domain, uniform magnetite nanocrystals in solution, as verified by using transmission electron microscopy analysis and magnetization measurements. The nanocrystals formed in the presence of ferritin, Lcn2, and BSA, do not exhibit the uniform sizes and shapes observed for those produced in the presence of Mms6. Mms6‐derived magnetite nanoparticles show the largest magnetization values above the blocking temperature, as well as the largest magnetic susceptibility compared to those of the nanomaterials synthesized with other proteins. The latter is indicative of a substantial effective magnetic moment per particle, which is consistent with the presence of magnetite with a well‐defined crystalline structure. The combination of electron microscopy analysis and magnetic measurements confirms our hypothesis that Mms6 promotes the shape‐selective formation of uniform superparamagnetic nanocrystals. This provides a unique bioinspired route for synthesis of uniform magnetite nanocrystals.
Fabrication of Superhydrophobic Surfaces on Engineering Materials by a Solution‐Immersion Process
Authors: Qu M. , Zhang B. , Song S. , Chen L. , Zhang J. , Cao X. 
Published: January 2007

AbstractSuperhydrophobic surfaces on engineering materials are prepared via a convenient solution‐immersion method. The binary geometric structures at the micro‐ and nanometer scale bestow superhydrophobic properties on the surfaces. The surfaces show stable superhydrophobicity even in many corrosive solutions, such as acidic or basic solutions over a wide pH range, and also in salt solutions. The procedure is time‐saving, inexpensive, and fairly facile to carry out. It is expected that this facile technique will accelerate the large‐scale production of superhydrophobic engineering materials with new industrial applications.
Colloidal Suspensions of Nanometer‐Sized Mesoporous Silica
Authors: Möller K. , Kobler J. , Bein T. 
Published: January 2007

AbstractNanometer‐sized surfactant‐templated materials are prepared in the form of stable suspensions of colloidal mesoporous silica (CMS) consisting of discrete, nonaggregated particles with dimensions smaller than 200 nm. A high‐yield synthesis procedure is reported based on a cationic surfactant and low water content that additionally enables the adjustment of the size range of the individual particles between 50 and 100 nm. Particularly, the use of the base triethanolamine (TEA) and the specific reaction conditions result in long‐lived suspensions. Dynamic light scattering reveals narrow particle size distributions in these suspensions. Smooth spherical particles with pores growing from the center to the periphery are observed by using transmission electron microscopy, suggesting a seed‐growth mechanism. The template molecules could be extracted from the nanoscale mesoporous particles via sonication in acidic media. The resulting nanoparticles give rise to type IV adsorption isotherms revealing typical mesopores and additional textural porosity. High surface areas of over 1000 m2 g–1 and large pore volumes of up to 1 mL g–1 are obtained for these extracted samples.
Sulfonation of poly(phthalazinone ether sulfone ketone) by heterogeneous method and its potential application on proton exchange membrane (PEM)
Authors: Wu Xuemei , He Gaohong , Gu Shuang , Chen Wan , Yao Pingjing 
Published: January 2007

AbstractA series of sulfonated PPESK (SPPESKs) were synthesized through a heterogeneous sulfonation process with fuming sulfuric acid as sulfonating agent in a chloroform solvent. Membranes prepared from SPPESKs were investigated and proved to be candidates of proton exchange membrane in fuel cell operating at high temperature and low humidity. The heterogeneous sulfonation reaction is verified to first occur on the interface of the acid phase and the chloroform phase, then went on in the acid phase. SPPESKs with sulfonation degree (DS) up to 2.0 are obtained through a new reprecipitation method. Effects of reaction temperature, reaction time, acid/polymer ratio, and chloroform/polymer ratio on the sulfonation reaction are reported in details. An increase in sulfonation degree results in the increase of hydrophilicity, bringing about a substantial gain in proton conductivity. SPPESK membranes exhibit high water uptake of about 105.4% with DS of 1.01, almost two times higher than that of Nafion® with similar dimensional variation. Conductivity values at 35°C, 60% R.H. ranging from 10−3 to 10−2 S/cm were measured, which are comparable to or higher than that of Nafion® 112 (1.635 × 10−2 S/cm) under the same test condition. Thermogravimetric analysis shows that SPPESK membranes are stable up to 290°C in N2. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1002–1009, 2007
Morphology of poly(styrene‐block‐dimethylsiloxane) copolymer films
Authors: Wu Ningjing , Zheng Anna , Huang Yongmin , Liu Honglai 
Published: January 2007

AbstractThe morphologies of poly(styrene‐block‐di‐methylsiloxane) (PS‐b‐PDMS) copolymer thin films were analyzed via atomic force microscopy and transition electron microscopy (TEM). The asymmetric copolymer thin films spin‐cast from toluene onto mica presented meshlike structures, which were different from the spherical structures from TEM measurements. The annealing temperature affected the surface morphology of the PS‐b‐PDMS copolymer thin films; the polydimethylsiloxane (PDMS) phases at the surface were increased when the annealing temperature was higher than the PDMS glass‐transition temperature. The morphologies of the PS‐b‐PDMS copolymer thin films were different from solvent to solvent; for thin films spin‐cast from toluene, the polystyrene (PS) phase appeared as pits in the PDMS matrix, whereas the thin films spin‐cast from cyclohexane solutions exhibited an islandlike structure and small, separated PS phases as protrusions over the macroscopically flat surface. The microphase structure of the PS‐b‐PDMS copolymer thin films was also strongly influenced by the different substrates; for an asymmetric block copolymer thin film, the PDMS and PS phases on a silicon substrate presented a lamellar structure parallel to the surface at intervals. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1010–1018, 2007
Effect of glycolide monomer on release behavior of gentamicin sulfate‐loaded PLGA microparticles
Authors: Yoo Je Young , Shin Joon Hyun , Khang Gilson , Shin Hyung Sik , Yuk Soon Hong , Kim Yong Sik , Kim Moon Suk , Rhee John M. , Lee Hai Bang 
Published: January 2007

AbstractFor the treatment of osteomyelitis and the prevention of infections after orthopedic surgery, topically implantable gentamicin sulfate (GS)‐loaded poly(D,L‐lactide‐co‐glycolide) microparticles (GSMP) containing glycolide monomer (GM), as a biodegradable and nontoxic material, were prepared by melt‐extrusion method without organic solvent for controlled release. After preparation of polymer blend, the powders of different size (90–1200 μm) were obtained by means of freezer‐mill. The influences of GM and particle size were investigated on the GS release patterns. GSMP containing GM (in case of 10% loaded) showed a near‐zero order release from 2 to 7 days with the initial burst. GM affected to increase of GS release rate during the in vitro release test. The pH variations of the media were investigated to determine effect of GM on pH drop of media. The morphological evaluations, change of molecular weight, and thermal property of microparticles were characterized by scanning electron microscope, gel permeation chromatography, and differential scanning calorimeter, respectively. Bacterial inhibition zone test was established to identify antibiosis of GS. It showed antibiotic areas except control sample. From these results, the authors expected that GSMP containing GM would be a good dosage form as a topically implantable device that can get rid of lag period of GSMP. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1019–1025, 2007