bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absolute configuration assignment of (3‐phenyloxirane‐2,2‐diyl)bis(phenylmethanone) via density functional calculations of optical rotation and vibrational circular dichroism
Authors: Lattanzi Alessandra , Russo Alessio , Rizzo Paola , Monaco Guglielmo , Zanasi Riccardo 
Published: April 2010

AbstractDensity Functional Theory (DFT) calculations of optical rotation (OR) and vibrational circular dichroism (VCD) have been used to assign the absolute configuration (AC) of a recently prepared (3‐phenyloxirane‐2,2‐diyl)bis(phenylmethanone), 3, by asymmetric epoxidation of the corresponding 2‐arylidene‐1,3‐diketone. The experimental OR at 589.3 nm and the VCD spectrum of the (+)‐ and (−)‐enantiomer of 3 have been measured. The conformationally‐averaged OR value and VCD spectrum of (R)‐3 were calculated at B3LYP/6‐311G(2d,2p) level of theory. Both approaches provide the same absolute configuration of the stereogenic carbon, i.e. the AC of (+)‐3 is (R)‐3, thus affording a confident assignment. Only two conformational isomers of 3 have been predicted to be populated at ambient temperature. Their presence is directly observed in the VCD spectrum. Chirality 2010. © 2010 Wiley‐Liss, Inc.
Preparation of a Novel Copolymer of Hyperbranched Polyglycerol with Multi‐arms of Poly(N‐isopropylacrylamide)
Authors: Pan Mugang , Wan Decheng , Huang Junlian 
Published: April 2010

AbstractA novel copolymer (PG‐PNIPAM) composed of polyglycerol (PG) as core and poly(N‐isopropylacrylamide) (PNIPAM) as arms was prepared by the radical addition‐fragmentation transfer polymerization (RAFT) of NIPAM in the presence of PG with multi‐trithiolcarbonate groups (PG‐TTC). The results showed that the RAFT polymerization was controllable and nearly all trithiolcarbonates groups on PG took part in the polymerization. The final PG‐PNIPAM copolymer showed a thermally dependent hydrophobic/hydrophilic transition around 28–30°C.
Adsorption Studies of Radionuclides and Toxic Metal Ions on a Modified Mesoporous Lanthanum(III) Silicate
Authors: Sepehrian Hamid , Ahmadi Syed Javad , Waqif‐Husain Syed , Zolfaghari‐Daryani Ahmad Reza , Azadmousavi Mortaza 
Published: April 2010

AbstractA new adsorbent, modified mesoporous lanthanum(III) silicate, has been prepared with various molar ratios of Si/La (10, 20, 40, 80) and cethyltrimethylammonium bromide (CTAB) as structure directing agent. XRD, nitrogen sorption, SEM, IR, thermogravimetry and sorption of radionuclides and toxic metal ions have been studied. The results show that adsorption amount of some element such as Pb(II) and Th(IV) has been increased significantly by incorporation of lanthanum ions in the framework of adsorbent. Separation of Co(II)‐Th(IV), Co(II)‐U(VI) and Mo(VI)‐U(VI) has been developed on columns of this adsorbent.
[Fe(III)(salophen)]Cl in Molten Tetrabutylammonium Bromide as a New Homogeneous Catalytic System for the Electrophilic Reaction of Indole with Carbonyl Compounds
Authors: Saeidnia Samira , Sheikhshoaie Iran 
Published: April 2010

Abstract[Fe(III)(salophen)]Cl in molten tetrabutylammonium bromide was used as a cost effective and efficient catalytic system for the electrophilic reaction of indole with carbonyl compounds. The remarkable features of this new procedure are high conversions, short reaction time, clean reaction profiles and simple experimental and work‐up procedures.
Measuring Quantitatively the Deterioration Degree of Ancient Silk Textiles by Viscometry
Authors: Zhang Xiaomei , Yuan Sixun 
Published: April 2010

AbstractSilk is made of natural protein, and can be damaged by heat, light, hydrolysis, etc. It deteriorates during burial, storage, display, studying and conservation treatment such as cleaning. Ancient silk fabrics are very precious, so their deterioration in museums has long been a concern for many conservators. To better preserve these textiles, early detection and quantitative assessment of damage is essential. Modern cultivated silk samples were artificially aged by simulating three main natural aging factors: light, heat and hydrolysis. Using these samples, the potential of viscometry for the quantitative assessment of silk damage was studied systematically by comparing with tensile strength testing. The results of this research show that viscometry is sensitive to the small changes in silk molecular weight resulting from deterioration. The technique is a useful method for the detection of ancient silk fabrics.
1,4‐Diaza‐bicyclo[2,2,2]octane as a Novel and Efficient Catalyst for the Synthesis of 3,4,6‐Trisubstituted 2‐Pyridone Derivatives
Authors: Heravi Majid M. , Tahershamsi Leili , Oskooie Hossein A. , Baghernejad Bita 
Published: April 2010

Abstract3,4,6‐Trisubstituted 2‐pyridone derivatives have been synthesized in good to excellent yields through a condensation reaction of various 1,3‐diketones with amides in the presence of 1,4‐Diaza‐bicyclo[2,2,2]octane (DABCO) at reflux temperature.
High Resolution of Racemic Mandelic Acid through a Method of Bubble Fractionation
Authors: Jiao Feipeng , Li Lin , Chen Xiaoqing , Hu Yuehua , Yang Ling 
Published: April 2010

AbstractA method of bubble fractionation was developed for the resolution of racemic mandelic acid (MA), using 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as chiral collector. The influences of concentration of HP‐β‐CD, reflux equilibriation time, gas flow rate, packing height of column and pH of buffer on resolution performance were investigated, respectively. According to the similar physical behavior of bubble fractionation and chemical reaction processes, the equivalent chemical reaction constant was introduced. The resolution process was preliminarily analyzed by means of kinetics. The results show that the enantiomeric excess of 60.7% can be obtained under the optimal conditions. The process could be regarded as a first order chemical reaction, where the equivalent speed constant was kl=0.00376. This method is helpful for realizing high resolution and linear amplification of device.
Modified weights based generalized quasilikelihood inferences in incomplete longitudinal binary models
Authors: Sutradhar Brajendra C. , Mallick Taslim S. 
Published: April 2010

AbstractIn an incomplete longitudinal set up, a small number of repeated responses subject to an appropriate missing mechanism along with a set of covariates are collected from a large number of independent individuals over a small period of time. In this set up, the regression effects of the covariates are routinely estimated by solving certain inverse weights based generalized estimating equations. These inverse weights are introduced to make the estimating equation unbiased so that a consistent estimate of the regression parameter vector may be obtained. In the existing studies, these weights are in general formulated conditional on the past responses. Since the past responses follow a correlation structure, the present study reveals that if the longitudinal data subject to missing mechanism are generated by accommodating the longitudinal correlation structure, the conditional weights based on past correlated responses may yield biased and hence inconsistent regression estimates. The bias appears to get larger as the correlation increases. As a remedy, in this paper the authors proposed a modification to the formulation of the existing weights so that weights are not affected directly or indirectly by the correlations. They have then exploited these modified weights to form a weighted generalized quasi‐likelihood estimating equation that yields unbiased and hence consistent estimates for the regression effects irrespective of the magnitude of correlation. The efficiencies of the regression estimates follow due to the use of the true correlation structure as a separate longitudinal weights matrix in the estimating equation. The Canadian Journal of Statistics © 2010 Statistical Society of Canada
A prospective cohort study defining utilities using time trade‐offs and the Euroqol‐5D to assess the impact of cancer‐related lymphedema
Authors: Cheville Andrea L. , Almoza Mously , Courmier Janice N. , Basford Jeffrey R. 
Published: April 2010

AbstractBACKGROUND:The devastating impact of lymphedema on cancer survivors' quality of life has prompted consideration of several changes in medical and surgical care. Unfortunately, our understanding of the benefits gained from these approaches relative to their cost remains limited. This study was designed to estimate utilities for lymphedema and characterize how utilities differ between subgroups defined by lymphedema etiology and distribution.METHODS:A consecutive sample of 236 subjects with lymphedema seen at a lymphedema clinic completed both a time trade‐off (TTO) exercise and the Euroqol 5D. Responses were adjusted in multivariate regression models for demographic factors, comorbidities, and lymphedema severity/location.RESULTS:Most participants (167 of 236, 71%) had lymphedema as a consequence of cancer treatment; 123 with breast cancer and upper extremity involvement. Mean TTO utility estimates were consistently higher than Euroqol 5D estimates. Unadjusted TTO (0.85; standard deviation [SD], 0.21) and Euroqol 5D (0.76; SD, 0.18) scores diminished with increasing lymphedema stage and patient body mass index (BMI). Adjusted utility scores were lowest in patients with cancer‐related lower extremity lymphedema (TTO = 0.82; SD, 0.04 and Euroqol 5D = 0.80; SD, 0.03). Breast cancer patients also had lower adjusted Euroqol 5D scores (0.80; SD, 0.02).CONCLUSIONS:Lymphedema‐associated utilities are in the range of 0.80. Lower utilities are observed for patients with higher lymphedema stages, elevated BMI, and cancer‐related lymphedema. Greater expenditures for the prevention and treatment of cancer‐related lymphedema are warranted. Cancer, 2010. © 2010 American Cancer Society.
Validation and simplification of a score predicting survival in patients irradiated for metastatic spinal cord compression
Authors: Rades Dirk , Douglas Sarah , Veninga Theo , Stalpers Lukas J.A. , Hoskin Peter J. , Bajrovic Amira , Adamietz Irenaeus A. , Basic Hiba , Dunst Juergen , Schild Steven E. 
Published: April 2010

AbstractBACKGROUND:Based on an analysis of 1852 retrospectively evaluated patients with metastatic spinal cord compression (MSCC), a scoring system was developed to predict survival. This study was performed to validate the scoring system in a new data set.METHODS:The score included 6 prognostic factors: tumor type, interval between tumor diagnosis and MSCC, other bone or visceral metastases, ambulatory status, and duration of motor deficits. Scores ranged between 20 and 45 points, and patients were initially divided into 5 groups: those with 20 to 25 points, those with 26 to 30 points, those with 31 to 35 points, those with 36 to 40 points, and those with 41 to 45 points. To facilitate the clinical use of the score, the patients were regrouped into 3 groups: those with 20 to 30 points, those with 31 to 35 points, and those with 36 to 45 points. In this study, data of 439 new patients were included who were divided into the same prognostic groups as in the preceding study.RESULTS:In this study, the 6‐month survival rates were 7% (for those with 20‐25 points), 19% (for those with 26‐30 points), 56% (for those with 31‐35 points), 73% (for those with 36‐40 points), and 90% (for those with 41‐45 points), respectively (P < .0001). After regrouping, the 6‐month survival rates were 14% (for those with 20‐30 points), 56% (for those with 31‐35 points), and 80% (for those with 36‐45 points), respectively, in this study (P < .0001).CONCLUSIONS:In the current study, the difference in 6‐month survival between the prognostic groups was found to be as significant as in the preceding study. Thus, this scoring system was considered valid to estimate survival of MSCC patients. The system could have been simplified by including only 3 instead of 5 prognostic groups. Cancer 2010. © 2010 American Cancer Society.
Morphology and mosaics of melanopsin‐expressing retinal ganglion cell types in mice
Authors: Berson David M. , Castrucci Ana Maria , Provencio Ignacio 
Published: April 2010

AbstractMelanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs). Melanopsin immunoreactivity reveals two dendritic plexuses within the inner plexiform layer (IPL) and morphologically heterogeneous retinal ganglion cells. Using enhanced immunohistochemistry, we provide a fuller description of murine cell types expressing melanopsin, their contribution to the plexuses of melanopsin dendrites, and mosaics formed by each type. M1 cells, corresponding to the originally described ganglion‐cell photoreceptors, occupy the ganglion cell or inner nuclear layers. Their large, sparsely branched arbors (mean diameter 275 μm) monostratify at the outer limit of the OFF sublayer. M2 cells also have large, monostratified dendritic arbors (mean diameter 310 μm), but ramify in the inner third of the IPL, within the ON sublayer. There are ≈900 M1 cells and 800 M2 cells per retina; each type comprises roughly 1–2% of all ganglion cells. The cell bodies of M1 cells are slightly smaller than those of M2 cells (mean diameters: 13 μm for M1, 15 μm for M2). Dendritic field overlap is extensive within each type (coverage factors ≈3.8 for M1 and 2.5 for M2 cells). Rare bistratified cells deploy terminal dendrites within both melanopsin‐immunoreactive plexuses. Because these are too sparsely distributed to permit complete retinal tiling, they lack a key feature of true ganglion cell types and may be anomalous hybrids of the M1 and M2 types. Finally, we observed weak melanopsin immunoreactivity in other ganglion cells, mostly with large somata, that may constitute one or more additional types of melanopsin‐expressing cells. J. Comp. Neurol. 518:2405–2422, 2010. © 2010 Wiley‐Liss, Inc.
A coupling system for connecting switch mode inverters to magnetic loops
Authors: Theodoridis Michael P. , Mollov Stefan V. 
Published: April 2010

AbstractThis paper presents the analysis and design of a coupling system that allows magnetic loops to be connected efficiently to switch mode (SM) inverters. The coupling method involved has been traditionally used with linear amplifiers and transmission lines. The objective of this work is to develop a design procedure that is suitable for SM inverters. A detailed analysis is carried out on this coupling method and a design procedure is presented with an aim to optimize the operation of the inverter. The design procedure was used to build a 13.56 MHz prototype, the measurements from which they align very well with the theoretical predictions. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis and design of a two‐transformer active‐clamping forward converter with parallel‐connected current doubler rectifiers
Authors: Lo Yu‐Kang , Lin Chung‐Yi , Lin Jing‐Yuan , Chiu Huang‐Jen 
Published: April 2010

AbstractA new two‐transformer active‐clamping forward converter with parallel‐connected current doubler rectifiers (CDRs) is proposed in this paper. The presented DC–DC converter is mainly composed of two active‐clamping forward converters with secondary CDRs. Only two switches are required and each one is the auxiliary switch for the other. The circuit complexity and cost are thus reduced. The leakage inductance of the transformer or an additional resonant inductance is employed to achieve zero‐voltage‐switching (ZVS) during the dead times. Two CDRs at the secondary side are connected in parallel to reduce the current stresses of the secondary windings and the ripple current at the output side. Accordingly, the smaller output chokes and capacitors decrease the converter volume and increase the power density. Detailed analysis and design of the presented two‐transformer active‐clamping forward converter are described. Experimental results are recorded for a prototype converter with a DC input voltage of 130−−180V, an output voltage of 5 V and an output current of 40 A, operating at a switching frequency of 100 kHz. Copyright © 2010 John Wiley & Sons, Ltd.
Improving Networks‐on‐Chip performability: A topology‐based approach
Authors: Elmiligi Haytham , Morgan Ahmed A. , El‐Kharashi M. Watheq , Gebali Fayez 
Published: April 2010

AbstractThe performability metric is commonly used in Networks‐on‐Chip (NoC)‐based systems to represent their abilities to successfully complete specific tasks in finite time intervals. In this paper, we present a novel topology‐based performability model for NoC‐based systems. The model is used to evaluate the performability of NoC‐based systems at early design phases. A comparative study of nine commonly used network architectures is performed using the proposed model. The purpose of the study is to explore the impact of the network topology on the performability of NoC‐based systems. Using the output from this study, a new methodology is proposed to improve the performability of a given application at early design phases. In this methodology, a joint consideration of five design parameters (network topology, target application traffic distribution, mapping of processing elements, noise power, and voltage swing) is carried out. Using the proposed methodology, designers can select the optimal topology for a given application that maximizes system performability. The effectiveness of the proposed methodology in determining the optimal topology is verified by experimental work and validated through a case study of a video application. Copyright © 2010 John Wiley & Sons, Ltd.
On the input common‐mode voltage range of CMOS bulk‐driven input stages
Authors: Carrillo Juan M. , Torelli Guido , Domínguez Miguel A. , Duque‐Carrillo J. Francisco 
Published: April 2010

AbstractIn this paper the response of a bulk‐driven MOS Metal‐Oxide‐Semiconductor input stage over the input common‐mode voltage range is discussed and experimentally evaluated. In particular, the behavior of the effective input transconductance and the input current is studied for different gate bias voltages of the input transistors. A comparison between simulated and measured results, in standard 0.35‐µm CMOS Complementary Metal‐Oxide‐Semiconductor technology, demonstrates that the model of the MOS transistors is not sufficiently accurate for devices operating under forward bias conditions of their source‐bulkpnjunction. Therefore, the fabrication and the experimental evaluation of any solution based on this approach are highly recommended. A technique to automatically control the gate bias voltage of a bulk‐driven differential pair is proposed to optimize the design tradeoff between the effective input transconductance and the input current. The proposed input stage was integrated as a standalone block and was also included in a 1.5‐V second‐order operational transconductance amplifier (OTA)‐Clowpass filter. Experimental results validate the effectiveness of the approach. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐switch flyback PWM DC–DC converter in discontinuous‐conduction mode
Authors: Murthy‐Bellur Dakshina , Kazimierczuk Marian K. 
Published: April 2010

AbstractThe two‐switch flyback DC–DC converter is an extended version of the conventional single‐switch flyback converter. An additional switch and two clamping diodes serve as a simple, but an effective way to limit the switch overvoltages, which occur in the conventional single‐switch flyback converter due to the ringing of the resonant circuit formed by the transformer leakage inductance and the transistor output capacitance. The clamping diodes in the two‐switch flyback topology clamp the maximum voltage across each switch equal to the DC input voltage. This paper presents a detailed analysis and design procedure of the diode‐clamped two‐switch flyback converter operated in discontinuous‐conduction mode (DCM). A comparison of power losses of the two‐switch and the single‐switch flyback converters is given. The two‐switch flyback converter was bread‐boarded to validate the theoretical analysis. Experimental results from a 20‐V/30‐W, 100‐kHz laboratory prototype verified that the maximum switch voltage is limited to the DC input voltage. Copyright © 2010 John Wiley & Sons, Ltd.
A new hyperchaotic Lorenz‐type system: Generation, analysis, and implementation
Authors: Li Yuxia , Liu Xuezhen , Chen Guanrong , Liao Xiaoxin 
Published: April 2010

AbstractA new four‐dimensional continuous‐time autonomous hyperchaotic Lorenz‐type system is introduced and analyzed. This hyperchaotic system is not only visualized by computer simulation but also verified with bifurcation analysis and realized with an electronic circuit. Moreover, explicit formulae for estimating the ultimate bound and positive invariant set of the system are derived by constructing a family of generalized Lyapunov functions. The findings and results of this paper have good potential in control and synchronization of hyperchaos and their engineering applications. Copyright © 2010 John Wiley & Sons, Ltd.
A flexible current‐mode classifier circuit and its applications
Authors: Yıldız Merih , Minaei Shahram , Göknar İzzet Cem 
Published: April 2010

AbstractIn this paper a new CMOS classifier circuit is presented, simulated, and compared with other recently introduced circuits. The proposed CMOS circuit operates in current‐mode and can classify several types of data. The architecture is designed using two threshold circuits and a subtraction circuit. Among many possible applications of the classifier circuit, template‐based pattern classification, namely template matching and character recognition with corruption, and in another direction its use as a quantizer are given. Using 0.35‐ µm AMS technology parameters, SPICE simulations as well as hard realization results for the classifier and application circuits are included; detailed Monte Carlo analyses to assess parameter mismatch effects are also performed. Copyright © 2010 John Wiley & Sons, Ltd.
Asynchronous cellular logic network as a co‐processor for a general‐purpose massively parallel array
Authors: Lopich Alexey , Dudek Piotr 
Published: April 2010

AbstractThis paper demonstrates an implementation of an asynchronous cellular processor array that facilitates binary trigger‐wave propagations, extensively used in various image‐processing algorithms. The circuit operates in a continuous‐time mode, achieving high operational performance and low‐power consumption. An integrated circuit with proof‐of‐concept array of 24×60 cells has been fabricated in a 0.35µm three‐metal CMOS process and tested. Occupying only 16×8µm2the binary wave‐propagation cell is designed to be used as a co‐processor in general‐purpose processor‐per‐pixel arrays intended for focal‐plane image processing. The results of global operations such as object reconstruction and hole filling are presented. Copyright © 2010 John Wiley & Sons, Ltd.
All‐pass filters using DDCC‐ and MOSFET‐based electronic resistor
Authors: Metin Bilgin , Pal Kirat , Cicekoglu Oguzhan 
Published: April 2010

AbstractThe main motivation in this paper is to draw attention to the tunability and input‐signal amplitude limitations when a nonlinear device is used as a resistor. For this purpose, two first‐order all‐pass filters are proposed using differential difference current conveyor (DDCC), a capacitor and a resistor without element‐matching restriction. These all‐pass filter circuits can be made electronically tunable with electronic resistors. Tunability and input‐signal amplitude limitations of the proposed circuits due to the operational restrictions of the electronic resistors are examined. PSPICE simulations confirm the validity and the practical utility of the proposed circuits. Copyright © 2010 John Wiley & Sons, Ltd.