bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amyloid imaging in mild cognitive impairment subtypes
Authors: Wolk David A. , Price Julie C. , Saxton Judy A. , Snitz Beth E. , James Jeffrey A. , Lopez Oscar L. , Aizenstein Howard J. , Cohen Ann D. , Weissfeld Lisa A. , Mathis Chester A. , Klunk William E. , DeKosky Steven T. 
Published: March 2009

AbstractObjectiveWe utilized the amyloid imaging ligand Pittsburgh Compound B (PiB) to determine the presence of Alzheimer's disease (AD) pathology in different mild cognitive impairment (MCI) subtypes and to relate increased PiB binding to other markers of early AD and longitudinal outcome.MethodsTwenty‐six patients with MCI (13 single‐domain amnestic‐MCI [a‐MCI], 6 multidomain a‐MCI, and 7 nonamnestic MCI) underwent PiB imaging. Twenty‐three had clinical follow‐up (21.2 ± 16.0 [standard deviation] months) subsequent to their PiB scan.ResultsUsing cutoffs established from a control cohort, we found that 14 (54%) patients had increased levels of PiB retention and were considered “amyloid‐positive.” All subtypes were associated with a significant proportion of amyloid‐positive patients (6/13 single‐domain a‐MCI, 5/6 multidomain a‐MCI, 3/7 nonamnestic MCI). There were no obvious differences in the distribution of PiB retention in the nonamnestic MCI group. Predictors of conversion to clinical AD in a‐MCI, including poorer episodic memory, and medial temporal atrophy, were found in the amyloid‐positive relative to amyloid‐negative a‐MCI patients. Longitudinal follow‐up demonstrated 5 of 13 amyloid‐positive patients, but 0 of 10 amyloid‐negative patients, converted to clinical AD. Further, 3 of 10 amyloid‐negative patients “reverted to normal.”InterpretationThese data support the notion that amyloid‐positive patients are likely to have early AD, and that the use of amyloid imaging may have an important role in determining which patients are likely to benefit from disease‐specific therapies. In addition, our data are consistent with longitudinal studies that suggest a significant percentage of all MCI subtypes will develop AD. Ann Neurol 2009;65:557–568
A γ‐secretase inhibitor decreases amyloid‐β production in the central nervous system
Authors: Bateman Randall J. , Siemers Eric R. , Mawuenyega Kwasi G. , Wen Guolin , Browning Karen R. , Sigurdson Wendy C. , Yarasheski Kevin E. , Friedrich Stuart W. , DeMattos Ronald B. , May Patrick C. , Paul Steven M. , Holtzman David M. 
Published: March 2009

AbstractObjectiveAccumulation of amyloid‐β (Aβ) by overproduction or underclearance in the central nervous system (CNS) is hypothesized to be a necessary event in the pathogenesis of Alzheimer's disease. However, previously, there has not been a method to determine drug effects on Aβ production or clearance in the human CNS. The objective of this study was to determine the effects of a γ‐secretase inhibitor on the production of Aβ in the human CNS.MethodsWe utilized a recently developed method of stable‐isotope labeling combined with cerebrospinal fluid sampling to directly measure Aβ production during treatment of a γ‐secretase inhibitor, LY450139. We assessed whether this drug could decrease CNS Aβ production in healthy men (age range, 21–50 years) at single oral doses of 100, 140, or 280mg (n = 5 per group).ResultsLY450139 significantly decreased the production of CNS Aβ in a dose‐dependent fashion, with inhibition of Aβ generation of 47, 52, and 84% over a 12‐hour period with doses of 100, 140, and 280mg, respectively. There was no difference in Aβ clearance.InterpretationStable isotope labeling of CNS proteins can be utilized to assess the effects of drugs on the production and clearance rates of proteins targeted as potential disease‐modifying treatments for Alzheimer's disease and other CNS disorders. Results from this approach can assist in making decisions about drug dosing and frequency in the design of larger and longer clinical trials for diseases such as Alzheimer's disease, and may accelerate effective drug validation. Ann Neurol 2009
Early imaging correlates of subsequent motor recovery after stroke
Authors: Marshall Randolph S. , Zarahn Eric , Alon Leeor , Minzer Brandon , Lazar Ronald M. , Krakauer John W. 
Published: March 2009

AbstractObjectiveTo determine whether functional magnetic resonance imaging activation obtained in the first few days after stroke correlates with subsequent motor recovery.MethodsTwenty‐three patients with hemiparesis after first‐time stroke were scanned at 2.0 ± 0.9 days while performing a simple motor task. We defined recovery as the change in Fugl–Meyer score from time of scan to approximately 3 months later (90 ± 8 days). We performed three different tests to assess correlations between brain activation and change in Fugl–Meyer score: (1) multivariate (most sensitive to spatially diffuse activation); (2) voxel‐wise Statistical Parametric Mapping (most sensitive to focal activation), and (3) primary motor cortex region‐of‐interest analysis (most sensitive to average activation within this region). All tests controlled for initial stroke severity and lesion volume, as well as other established clinical variables.ResultsThe multivariate test was significant [F (595, 4,934) = 1.93; p < 0.001]. The Statistical Parametric Mapping test detected two small clusters of focal activity located in the ipsilesional postcentral gyrus and cingulate cortex (p < 0.05, corrected). The region‐of‐interest test was not significant.InterpretationThere is a pattern of brain activation present in the first few days after stroke, of which the postcentral gyrus and cingulate cortex are a part, that correlates with subsequent motor recovery. This result suggests that there are recovery processes engaged early after stroke that could provide a target for intervention. Ann Neurol 2009;65:596–602
A Detection System Based on Giant Magnetoresistive Sensors and High‐Moment Magnetic Nanoparticles Demonstrates Zeptomole Sensitivity: Potential for Personalized Medicine
Authors: Srinivasan Balasubramanian , Li Yuanpeng , Jing Ying , Xu YunHao , Yao Xiaofeng , Xing Chengguo , Wang Jian‐Ping 
Published: March 2009

AbstractEin zeptomolarer Detektor: Ein hoch empfindlicher Chip mit Riesenmagnetwiderstand in Kombination mit FeCo‐Nanopartikeln ermöglicht die lineare Detektion von nur 600–4500 Streptavidin‐Molekülen. Schon unter nichtoptimierten Bedingungen erkennt das System überdies humanes IL‐6 mit einer 13‐mal höheren Empfindlichkeit als ELISA‐Standardtechniken.magnified image
5‐(Pyrrolidin‐2‐yl)tetrazole‐Catalyzed Aldol and Mannich Reactions: Acceleration and Lower Catalyst Loading in a Continuous‐Flow Reactor
Authors: Odedra Arjan , Seeberger Peter H. 
Published: March 2009

AbstractContinuous organocatalysis: Fast aldol and Mannich reactions require less catalyst when conducted in a microreactor. A proline tetrazole derivative (5–10 mol %) catalyzes asymmetric aldol reactions between various aromatic aldehydes and ketones in microreactor at 60 °C with reaction times ranging from 10 to 30 min.magnified image
A Preferred Disrotatory 4n Electron Möbius Aromatic Transition State for a Thermal Electrocyclic Reaction
Authors: Mauksch Michael , Tsogoeva Svetlana B. 
Published: March 2009

AbstractNot forbidden: Thermal 4n electron electrocyclic reactions of Hückel topology structures proceed via “allowed” conrotatory pathways. However, for a Möbius topology, the Woodward–Hoffmann rules may be reversed and a “forbidden” disrotatory pathway can be preferred as shown theoretically for dodecahexaene 1 that transforms via a Heilbronner–Möbius aromatic transition structure 2 into a cyclic polyene 3.magnified image
A Detection System Based on Giant Magnetoresistive Sensors and High‐Moment Magnetic Nanoparticles Demonstrates Zeptomole Sensitivity: Potential for Personalized Medicine
Authors: Srinivasan Balasubramanian , Li Yuanpeng , Jing Ying , Xu YunHao , Yao Xiaofeng , Xing Chengguo , Wang Jian‐Ping 
Published: March 2009

AbstractZeptomole detector: A highly sensitive giant‐magnetoresistive chip and FeCo nanoparticles can be used to linearly detect 600–4500 copies of streptavidin. Under unoptimized conditions, this system also detects human IL‐6 with a sensitivity 13‐times higher than that of standard ELISA techniques.magnified image
Peptides Recognize Photoresponsive Targets
Authors: Chen Jing , Serizawa Takeshi , Komiyama Makoto 
Published: March 2009

AbstractClones on film: 7‐mer peptides that bind to azobenzene‐containing polymer films were selected from a phage library under visible light. Isolated clones showed greater affinities to the films under ultraviolet light than those under visible light. Furthermore, the peptide binding responds to the photoinduced isomerization of azobenzene groups.magnified image
Direct Alkenylation of Indoles with α‐Oxo Ketene Dithioacetals: Efficient Synthesis of Indole Alkaloids Meridianin Derivatives
Authors: Yu Haifeng , Yu Zhengkun 
Published: March 2009

AbstractLet's make 'meri': Metal‐free direct alkenylation of indoles was realized by acid‐mediated substitution reactions of α‐oxo ketene dithioacetals with indoles in trifluoroacetic acid/dichloromethane, selectively affording β‐indolyl mono‐ and disubstituted α,β‐unsaturated carbonyl compounds (see scheme). Condensation of the indolyl/ketene monothioacetals and guanidine nitrate efficiently produced meridianin derivatives.magnified image
Linear and branched polyoxide‐based copolymers: Methods to determine the CMC
Authors: Silva Priscila R. S. , Mauro Aparecida C. , Mansur Claudia R. E. 
Published: March 2009

AbstractEvaluation of the physical–chemical properties of aqueous solutions of nonionic surfactants based on polyoxides can be performed by different methods. Depending on the technique used, there can be a significant variation in the critical micelle concentration (CMC) found. This is related to the sensitivity of the technique regarding the unimers and micelles present in the solution as well as the structure of the surfactant evaluated. In this work, the CMC values of aqueous solutions of linear and branched poly(ethylene oxide‐polypropylene oxide) (PEO‐PPO) block copolymers were determined by tensiometry, fluorescence, and particle size analysis, using copolymers having adjacent structures (that is, hydrophilic and hydrophobic segments located adjacently in the copolymer) and alternating structures. Tensiometry was used to measure the surface tension as a function of the copolymer concentration in aqueous solution. Fluorescence was used to determine the fluorescence intensity of pyrene to plot the graphs of the I1/I3 and IE/IM relations according to the surfactant concentration. Finally, particle size analysis was used to determine the diffusion coefficient of the particles. The results showed that the fluorescence and particle size techniques provide lower (and mutually concordant) CMC values and can be considered more precise because these methods directly analyze the bulk of the solution. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermal characteristics and crystallinity of Ziegler–Natta isotactic polypropylene/metallocene isotactic polypropylene polyblended fibers
Authors: Shu Yao‐Chi , Hsiao Kai‐Jen , Tsen Wen‐Chin 
Published: March 2009

AbstractZiegler–Natta isotactic polypropylene (ZN‐iPP) and metallocene isotactic polypropylene (m‐iPP) were extruded (in ratios of 75/25, 50/50, and 25/75) from one melt twin‐screw extruder to produce three ZN‐iPP/m‐iPP polyblended polymers and, subsequently, spin fibers. In this study, we examined the rheology of the ZN‐iPP/m‐iPP polyblended polymers and the thermal characteristics and crystallinity of the ZN‐iPP/m‐iPP polyblended fibers using gel permeation chromatography, rheometry, differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction, density gradient analysis, and extension stress–strain measurement. The apparent melt viscosity of the ZN‐iPP/m‐iPP polyblended polymers revealed positive‐deviation blends. The 50/50 blend of ZN‐iPP/m‐iPP had the highest apparent melt viscosity. For five samples, the complex melt viscosity decreased with the angular frequency, which represented typical non‐Newtonian behavior. The Cole–Cole plot, which consisted of the imaginary part of the complex melt viscosity versus the real part of the complex melt viscosity plot, of the ZN‐iPP/m‐iPP polyblended polymers showed a semicircular relationship with the blend ratios. It indicated that the ZN‐iPP/m‐iPP polyblended polymers were miscible. We analyzed the shear modulus data (G′ vsG″) by plotting them on a log–log scale. The plot revealed almost the same slopes for the ZN‐iPP/m‐iPP polyblended polymers, which indicated a good miscibility between the ZN‐iPP and m‐iPP polymers. The experimental DSC results demonstrate that the ZN‐iPP and m‐iPP polymers constituted a miscible system. The crystallinity and tenacity of the ZN‐iPP/m‐iPP polyblended fibers initially increased and then fell as the m‐iPP content increased. Meanwhile, the 50/50 blend of ZN‐iPP/m‐iPP had the highest crystallinity and tenacity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Function of Sirtuins in Biological Tissues
Authors: Shoba Balaji , Lwin Zin Mar , Ling Lo Soo , Bay Boon‐Huat , Yip George W. , Kumar Srinivasan Dinesh 
Published: March 2009

AbstractSirtuins are protein deacetylases, which are dependent on nicotine adenine dinucleotide. They are phylogenetically conserved from bacteria to humans. Seven sirtuin proteins localized in a wide variety of subcellular locations have been identified in the human genome. The most important known function of sirtuins is their regulation of transcriptional repression, mediated through binding of a complex containing sirtuins and other proteins. Studies have shown that sirtuins have pathophysiological relevance to neurodegeneration, muscle differentiation, inflammation, obesity, and cancer. In addition, sirtuin activity extends the lifespan of several organisms. In this review, we discuss the mode(s) of action of sirtuins, and their biological role(s) in health and disease. Anat Rec, 292:536–543, 2009. © 2009 Wiley‐Liss, Inc.
Demyelination Induces the Decline of the Myelinated Fiber Length in Aged Rat White Matter
Authors: Li Chen , Yang Shu , Zhang Wei , Lu Wei , Nyengaard Jens R. , Morrison John H. , Tang Yong 
Published: March 2009

AbstractTo determine the exact reason for the age‐related decline of the myelinated fiber length in white matter, we performed this study. In middle‐aged rats, there was age‐related loss of the unmyelinated fibers with large diameters. The demyelination of the myelinated fibers with small diameters in middle‐aged rat white matter might make the age‐related decrease of the unmyelinated fibers with small diameters in the white matter unnoticeable. However, in old‐aged female rats, the unmyelinated fibers with large and small diameters significantly degenerated together and that the unmyelinated fibers formed from the demyelination of the myelinated fibers could not replenish the age‐related loss of the unmyelinated fibers in the white matter. In conclusion, this study suggested that demyelination of myelinated fibers with small diameters in aged white matter might be the key mechanism of the significant decline of the myelinated fiber length in aged white matter. Anat Rec, 292:528–535, 2009. © 2009 Wiley‐Liss, Inc.
Rapid and label‐free bacteria detection by surface plasmon resonance (SPR) biosensors
Authors: Dudak Fahriye Ceyda , Boyacı İsmail Hakkı 
Published: March 2009

AbstractSurface Plasmon Resonance (SPR) biosensor technology has been successfully used for the detection of various analytes such as proteins, drugs, DNA, and microorganisms. SPR‐based immunosensors that coupled with a specific antigen‐antibody reaction, have become a promising tool for the quantification of bacteria as it offers sensitive, specific, rapid, and label‐free detection. In this paper, we review the important issues in the development of SPR‐based immunoassays for bacteria detection, concentrating on instrumentation, surface functionalization, liquid handling, and surface regeneration. In addition, this review touches on the recent advances in SPR biosensing for sensitivity enhancement.
Academic software for optimizing supply‐side bids in a wholesale electricity market
Authors: Mingo Luis M. , Angarita Jorge L. , Martínez‐Crespo Jorge 
Published: March 2009

AbstractThis article presents a MATLAB–General Algebraic Modeling System (GAMS) combined tool designed to define the optimal power bid to be submitted by generating agents in wholesale electricity markets. This computer application, called OPTIOFER, fits together the best GAMS and MATLAB features for the optimization of hydraulic and thermal generation bids models and their friendly visual representation. OPTIOFER makes use of GAMS to formulate and solve hydro and thermal models, whereas MATLAB and its toolbox GUIDE are used for implementation and graphical representation. The motivation for developing the package is to provide a flexible simulation environment for ongoing research conducted at the Electrical Engineering Department of Carlos III University, Madrid, Spain, and to enhance, mainly, graduate and M.S. power engineering courses. After a brief summary of power generating models considered for the bids formulation, the article illustrates the capabilities and main features of OPTIOFER using two simple hydraulic and thermal power systems as examples. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 457–465, 2011
CNC Partner: A novel training system for NC machining
Authors: Li Jianguang , Yao Yingxue , Wu Jing 
Published: March 2009

AbstractCNC Partner, a novel training system on NC machining, is presented in this paper. It creates a semi‐immersive desktop virtual training environment with a sense of high reality at a low cost. With the CNC Partner, a trainee can learn the knowledge of NC programming and acquire the practical operation skills on a CNC machine tool prior to operate a real one. The framework of CNC Partner is established and described in detail. And its functions on training are summarized. The functions of CNC Partner‐assisted teaching are also introduced. Up to now, over 200 sets of CNC Partner systems have been installed in several vocational education schools in China. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 466–474, 2011
Hydrogen‐Atom Transfer Reactions from ortho‐Alkoxy‐Substituted Phenols: An Experimental Approach
Authors: Amorati Riccardo , Menichetti Stefano , Mileo Elisabetta , Pedulli Gian Franco , Viglianisi Caterina 
Published: March 2009

AbstractDeceptively simple: Joint results obtained by EPR and IR spectroscopies and inhibited autoxidation studies allow an explanation, on quantitative grounds, of the factors determining the H‐atom donating abilities of 2‐alkoxyphenols (see graphic; blue: 2‐methoxyphenol, red: cyclic phenol).magnified imageThe role of intramolecular hydrogen bonding (HB) on the bond‐dissociation enthalpy (BDE) of the phenolic OH and on the kinetics of H‐atom transfer to peroxyl radicals (kinh) of several 2‐alkoxyphenols was experimentally quantified by the EPR equilibration technique and by inhibited autoxidation studies. These compounds can be regarded as useful models for studying the H‐atom abstraction from 2‐OR phenols, such as many lignans, reduced coenzyme Q and curcumin. The effects of the various substituents on the BDE(OH) of 2‐methoxy, 2‐methoxy‐4‐methyl, 2,4‐dimethoxyphenols versus phenol were measured in benzene solution as −1.8; −3.7; −5.4 kcal mol−1, respectively. In the case of polymethoxyphenols, significant deviations from the BDE(OH) values predicted by the additive effects of the substituents were found. The logarithms of the kinh constants in cumene were inversely related to the BDE(OH) values, obeying a linear Evans–Polanyi plot with the same slope of other substituted phenols and a y‐axis intercept slightly smaller than that of 2,6‐dimethyl phenols. In the cases of phenols having the 2‐OR substituent included in a five‐membered condensed ring (i.e, compounds 9–11), both conformational isomers in which the OH group points toward or away from the oxygen in position 2 were detected by FTIR spectroscopy and the intramolecular HB strength was thus estimated. The contribution to the BDE(OH) of the ortho‐OR substituent in 9, corrected for intramolecular HB formation, was calculated as −5.6 kcal mol−1. The similar behaviour of cyclic and non‐cyclic ortho‐alkoxy derivatives clearly showed that the preferred conformation of the OMe group in ortho‐methoxyphenoxyl radicals is that in which the methyl group points away from the phenoxyl oxygen, in contrast to the geometries predicted by DFT calculations.
Synthesis, Electronic Properties, and Reactivity of Phospholes and 1,1′‐Biphospholes Bearing 2‐ or 3‐Thienyl C‐Substituents
Authors: Fadhel Omrane , Szieberth Dénes , Deborde Valérie , Lescop Christophe , Nyulászi László , Hissler Muriel , Réau Régis 
Published: March 2009

AbstractPS, I love you! Novel mixed phosphole/thiophene π‐conjugated systems were synthesized and their electronic properties have been studied both experimentally by UV/Vis spectroscopy and electrochemistry and by theoretical calculations. Exploiting the chemistry of both P‐ and S‐heteroles allows the generation of a diverse range of novel ring‐fused benzophosphole–thiophene derivatives. magnified imageTwo series of phospholes and 1,1′‐biphospholes bearing either 2‐ or 3‐thienyl substituents at the C atoms are prepared by using the Fagan–Nugent route. Their optical (UV/Vis absorption, fluorescence spectra) and electrochemical properties are systematically evaluated. Of particular interest, the first ever reported 3‐thienyl‐substituted phospholes exhibit higher LUMO levels than their 2‐thienyl analogues, and show accordingly different physical properties. This study also reveals that the 1,1′‐biphospholes exhibit σ–π conjugation. The phosphole and 1,1′‐biphosphole derivatives bearing 3‐thienyl substituents are characterized by X‐ray diffraction study. The structure–property relationship established following the experimental data are fully supported by theoretical studies including time‐dependent(TD)‐DFT spectra. A photocyclization reaction performed on the thioxo‐ and oxophospholes having 3‐thienyl substituents affords a novel ring‐fused phosphole–thiophene derivative, which was characterized by an X‐ray diffraction study. The structure and electronic properties of this novel dithienophosphole are discussed based on experimental and theoretical data.
Phosphine‐Free Palladium‐Catalyzed Allene Carbopalladation/Allylic Alkylation Domino Sequence: A New Route to 4‐(α‐Styryl) γ‐Lactams
Authors: Kammerer Claire , Prestat Guillaume , Madec David , Poli Giovanni 
Published: March 2009

AbstractFree to decide: Various 4‐(α‐styryl) γ‐lactams are synthesized in 61–88 % yield by a phosphine‐free palladium‐catalyzed carbopalladation/allylic alkylation domino sequence (see scheme). The cyclization is totally regio‐ and diastereoselective in favor of the 3,4‐trans‐disubstituted γ‐lactam. The process is successfully applied to the synthesis of a new aza analogue of the naturally occurring lignan (+)‐oxo‐parabenzlactone.magnified image
Minimum spouting velocity in a spout‐fluid bed with a draft tube
Authors: Xu Jian , Tang Junli , Wei Weisheng , Bao Xiaojun 
Published: March 2009

AbstractMinimum spouting velocity was measured in a 0.12 m cylindrical spout‐fluid bed with a draft tube. The effects of fluidizing gas flow rate, entrainment height, and spout nozzle diameter on minimum spouting velocity were discussed. A correlation on minimum spouting velocity has been proposed based on the present experimental data.