bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anisotropic polyvinyl alcohol—Bacterial cellulose nanocomposite for biomedical applications
Authors: Millon Leonardo E. , Guhados Ganesh , Wan Wankei 
Published: February 2008

AbstractCompliance mismatch between the synthetic graft and the surrounding native tissue has been reported as a major factor in ultimate failure of the currently used cardiovascular graft replacements. Thus, developing biomaterials that display close mechanical properties as the tissue it is replacing is an important objective in biomedical devices design. Polyvinyl alcohol (PVA) is a biocompatible hydrogel with characteristics desired for biomedical applications. It can be crosslinked by a low temperature thermal cycling process. By using a novel thermal processing method under an applied strain and with the addition of a small amount of bacterial cellulose (BC) nanofibers, an anisotropic PVA‐BC nanocomposite was created. The stress–strain tensile properties of porcine aorta were closely matched in both the circumferential and the axial directions by one type of anisotropic PVA‐BC nanocomposite (10% PVA with 0.3% BC at 75% initial strain and cycle 2) within physiological range, with improved resistance to further stretch beyond physiological strains. The PVA‐BC nanocomposite gives a broad range of mechanical properties, including anisotropy, by controlling material and processing parameters. PVA‐BC nanocomposites with controlled degree of anisotropy that closely match the mechanical properties of the soft tissue it might replace, ranging from cardiovascular to other connective tissues, can be created. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Efficient calculation of configurational entropy from molecular simulations by combining the mutual‐information expansion and nearest‐neighbor methods
Authors: Hnizdo Vladimir , Tan Jun , Killian Benjamin J. , Gilson Michael K. 
Published: February 2008

AbstractChanges in the configurational entropies of molecules make important contributions to the free energies of reaction for processes such as protein‐folding, noncovalent association, and conformational change. However, obtaining entropy from molecular simulations represents a long‐standing computational challenge. Here, two recently introduced approaches, the nearest‐neighbor (NN) method and the mutual‐information expansion (MIE), are combined to furnish an efficient and accurate method of extracting the configurational entropy from a molecular simulation to a given order of correlations among the internal degrees of freedom. The resulting method takes advantage of the strengths of each approach. The NN method is entirely nonparametric (i.e., it makes no assumptions about the underlying probability distribution), its estimates are asymptotically unbiased and consistent, and it makes optimum use of a limited number of available data samples. The MIE, a systematic expansion of entropy in mutual information terms of increasing order, provides a well‐characterized approximation for lowering the dimensionality of the numerical problem of calculating the entropy of a high‐dimensional system. The combination of these two methods enables obtaining well‐converged estimations of the configurational entropy that capture many‐body correlations of higher order than is possible with the simple histogramming that was used in the MIE method originally. The combined method is tested here on two simple systems: an idealized system represented by an analytical distribution of six circular variables, where the full joint entropy and all the MIE terms are exactly known, and the R,S stereoisomer of tartaric acid, a molecule with seven internal‐rotation degrees of freedom for which the full entropy of internal rotation has been already estimated by the NN method. For these two systems, all the expansion terms of the full MIE of the entropy are estimated by the NN method and, for comparison, the MIE approximations up to third order are also estimated by simple histogramming. The results indicate that the truncation of the MIE at the two‐body level can be an accurate, computationally nondemanding approximation to the configurational entropy of anharmonic internal degrees of freedom. If needed, higher‐order correlations can be estimated reliably by the NN method without excessive demands on the molecular‐simulation sample size and computing time. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
MALDI mass spectrometric determination of dendritic iron chelation stoichiometries and conditional affinity constants
Authors: Kong Xiaole , Neubert Hendrik , Zhou Tao , Liu ZuDong , Hider Robert C. 
Published: February 2008

AbstractThe iron chelation stoichiometries of a dendritic iron(III) chelator with N1, N3, N5‐trimethylbenzene‐1,3,5‐tricarboxamide at its core, and containing 3 identical hexadentate tris‐hydroxypyridinone branches D was studied by MALDI mass spectrometry. At pH 7.2, the speciation of the system included FeD, Fe2D and Fe3D species with the respective conditional stability constants of 26.74, 26.03 and 25.36. The differences in the stepwise affinity constants arise from the statistical distribution of iron(III), and there was no evidence for cooperativity between the iron‐binding sites. Copyright © 2008 John Wiley & Sons, Ltd.
Imatinib metabolite profiling in parallel to imatinib quantification in plasma of treated patients using liquid chromatography–mass spectrometry
Authors: Rochat Bertrand , Fayet Aurélie , Widmer Nicolas , Lahrichi Sabine L. , Pesse Benoît , Décosterd Laurent A. , Biollaz Jérôme 
Published: February 2008

AbstractBesides affecting the systemic bioavailability of the parent drug, drug metabolizing enzymes (DMEs) may produce bioactive and/or toxic metabolites of clinical interest. We have investigated the capability to analyze simultaneously the parent drug and newly identified metabolites in patients' plasma by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS).The anticancer drug, imatinib, was chosen as a model drug because it has opened a new area in cancer therapy and is given orally and chronically. In addition, resistance and rare but sometimes severe side effects have been reported with this therapy.The quantification of imatinib and the profiling of its metabolites in plasma were established following three steps: (1) set‐up of a generic sample extraction and LC–MS/MS conditions, (2) metabolite identification by LC–MS/MS using eitherin vitroincubations performed with human liver microsomes (HLMs) or patient plasma samples, (3) the simultaneous determination of plasma levels of imatinib and 14 metabolites in the plasma samples of 38 patients.Partial or cross method validation has been done and revealed that precise determinations of metabolite levels can be performed whereas pure standards are not available.Preliminary results indicate that the disposition of imatinib and its metabolites is related to interindividual variables and that outlier metabolite profiles can be revealed.This article underscores that, in addition to usual therapeutic drug monitoring (TDM), LC–MS/MS methods can simultaneously record a complete drug metabolic profile enabling various correlation studies of clinical interest. Copyright © 2008 John Wiley & Sons, Ltd.
Substituted 3‐phenylpropenoates and related analogs: electron ionization mass spectral fragmentation and density functional theory calculations
Authors: Wheelock C. E. , Colvin M. E. , Sanborn J. R. , Hammock B. D. 
Published: February 2008

AbstractAnalysis of ethyl 3‐(2‐chlorophenyl)propenoate by electron ionization mass spectrometry showed the distinct loss of an ortho chlorine. To characterize the structural requisites for the observed mass fragmentation, a series of 30 halogen‐substituted 3‐phenylpropenoate‐related structures were examined. All ester‐containing alkene derivatives exhibited loss of the distinctive chlorine from the 2‐position of the phenyl ring. Analogous derivatives with the halogen (chlorine or bromine) in the para position did not evidence selective halogen loss. Results demonstrated that substituted 3‐phenylpropenoates and their analogs fragment via the formation of a previously reported benzopyrylium intermediate. To understand the correlation between the intramolecular radical substitution and the abundance and selectivity of the chlorine (or other halogen) displacement, density functional theory calculations were performed to determine the charge on the principal cation involved in the chlorine loss (in the ortho, meta, and para positions), the charge for the neutral radical (noncation), the excess alpha‐electron density on the relevant atom and the energy to form the cation from the neutral atom (ionization energy). Results showed that the selectivity and extent of halogen displacement correlated highly to the electrophilicity of the radical cation as well as the neutral radical. These data further support the proposed fragmentation mechanism involving intramolecular radical elimination. Copyright © 2008 John Wiley & Sons, Ltd.
X‐ray study of AlSi 7 alloy cast in sand mold using an ultrasound field
Authors: Mihoc E. R. , Porcar D.D. , Porcar I. 
Published: February 2008

AbstractThis paper shows some results obtained by X‐ray diffraction of an AlSi 7 alloy. The samples were cast in sand moulds, and an ultrasonic field during was used the solidification. The results show different behavior between classical sand cast mold alloy without and with ultrasound treatment. The presented analyses explain the improvement of some mechanical characteristics of the material.
Numerical model for composite structures with experimental confirmation
Authors: Harapin A. , Radnić J. , Ćubela D. 
Published: February 2008

AbstractThe paper briefly presents a numerical model for the simulation of composite structures. The main structure is modeled with two‐dimensional plane finite elements. The composite surface is modeled with two‐dimensional interface elements for the continuous connection simulation and modified beam elements for the discrete connection simulation. The applied material model’s primary purpose is the simulation of reinforced concrete structures. It includes the most important nonlinear effects of reinforced concrete behavior: yielding in compression and opening and propagation of cracks in tension, with tensile and shear stiffness of cracked concrete, as well as the nonlinear behavior of reinforced steel. It also includes nonlinear behavior of the composite surface and the connection elements. The model was confirmed in experimental tests of composite concrete Omnia slabs, which are in common usage. The achieved test results were compared with the results obtained through the developed numerical model.
Free flap coverage of gluteal defect using posteriorly translocated deep femoral vessels as recipient
Authors: Chang Li‐Ren , Lee Jing‐Wei 
Published: February 2008

AbstractA 63‐year‐old paraparetic man presented with a large ischial pressure sore over the left buttock region. A failed surgical attempt using gluteal thigh flap transfer rendered the reconstructive task a challenging issue. In the absence of suitable regional flaps or any accessible recipient vessels nearby, we must employ a novel strategy to solve the clinical problem. The entire length of the deep femoral vessel was isolated through the anterior approach, which was then transposed posterior wards to the gluteal region to nourish a latissimus dorsi myocutaneous free flap while the patient was laid prone. The wound healed uneventfully and the patient remains ulcer‐free throughout 3 years of follow‐up. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Improved long‐term recording of nerve signal by modified intrafascicular electrodes in rabbits
Authors: Jia Xiaofeng , Zhen Gehua , Puttgen Adrian , Zhang Jian , Chen Tongyi 
Published: February 2008

AbstractMethods for long‐term recording of peripheral nerve activity via intrafascicular electrodes have not been optimized. We compared the long‐term functionality of custom‐made 95%Pt/5%Ir intrafascicular electrodes containing a proximal spring‐like structure to that of conventional straight electrodes. The modified electrode was implanted into the sciatic nerve fascicle of a random hind limb in 14 rabbits for 9 months. A conventional electrode was implanted in the opposite hind limb as a control. Orthodromic and antidromic nerve potentials were sampled and analyzed monthly. Latency, amplitude, and nerve conduction velocity of electrical signals were generally similar within the modified group and straight control group at different time intervals (P > 0.05). However, at the conclusion of the study period, the modified electrode group had a greater number of functioning electrodes (P < 0.05) and a greater total functioning electrode time (P = 0.006). Intrafascicular electrodes with a spring‐like structure demonstrated superior potential for long‐term electrophysiological monitoring over straight electrodes. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Does the nicotine patch help in the postoperative period for arterial vessel repair?
Authors: Battista Vince , Fanua Sione P. , Shaw Wilgis E. F. 
Published: February 2008

AbstractThis study attempts to determine whether a nicotine patch will affect the patency rate of the femoral artery anastomosis in a smoking rat model. Twenty‐four rats underwent a smoking protocol of 4 weeks of exposure to cigarette smoke in a smoking chamber at 1 hour per day, using a 1:10 dilution of unfiltered cigarette smoke. Each rat then underwent a femoral artery transaction and anastomosis. Postoperatively, the rats were divided into two groups of 12. Group I had no postoperative smoking or nicotine therapy. Group II had nicotine patch treatment only. The femoral artery was evaluated for flow 7‐days postoperatively. At the time of anastomosis, the femoral arteries were smaller in diameter, averaging 0.5 mm (0.4–0.7 mm) as opposed to the normal 0.75–1 mm. All anastomoses were patent at 5 min when the wound was closed. No difference in patency rate occurred with the use of the nicotine patch. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Harmonic suppression of bandpass filters using open‐circuited stubs
Authors: Chen Lih‐Shan , Lin Wen‐Jeng , Huang Tsung‐Hui , Houng Mau‐Phon , Fu Shen‐Li 
Published: February 2008

AbstractIn this article, a cascaded bandstop filter using quarter‐wavelength open‐circuited stub structure is employed to suppress the spurious passband at the second harmonic of the bandpass filter. The center frequency of the fabricated bandpass filter is at 0.9 GHz and the fractional bandwidth is 5%. The proposed bandpass filter shows 30 dB rejection at the second harmonic during the frequency range from 1.1 to 10 GHz. The measured frequency responses of the fabricated filter are in agreement with simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 863–865, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23226
An extended omnipotent Smith chart with active parameters
Authors: Wu Yongle , Huang Haiyu , Liu Yuanan 
Published: February 2008

AbstractThe lossy nonreciprocal transmission line (LNTL) model with active characteristic impedances and active load impedances is researched in this article. For solving LNTL problems involving active parameters, the previous presented omnipotent Smith chart (OSC) is extended its domain of application. Though the formation of expression is unchanged, the extended OSC (EOSC) shows different characteristics. The EOSC is especially significant for the application in oscillator design and amplifier stabilization. An EOSC can be easily generated using Matlab or Java for applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 896–899, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23229
A direct method to extract RF MOSFET model parameters using common source‐gate and source‐drain configurations
Authors: Lee Seonghearn 
Published: February 2008

AbstractA direct extraction method is newly developed to determine RF MOSFET model parameters using two‐port parameter equation derived from two zero‐bias equivalent circuits under common source‐gate and source‐drain configurations. This method is much simpler and more accurate than conventional ones using common source‐bulk configuration, because parasitic resistances are directly extracted from low‐frequency data without a complicated linear regression of high‐frequency data and capacitances are directly determined without any inappropriate assumptions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 915–917, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23231
Microstrip parallel coupled‐line bandpass filter with selectivity improvement using U‐shaped defected ground structure
Authors: Piscarreta Daniel , Ting Sio‐Weng 
Published: February 2008

AbstractA novel defected ground structure (DGS) feedline element with two transmission zeros and flat passband is proposed. The zeros can be tuned individually by the DGS geometry to improve the low order filter's selectivity. A traditional microstrip parallel coupled‐line bandpass filter cascading this new element, not only achieves the selectivity improvement, but also its basic design formulation is retained. A prototype DGS filter was designed and tested to validate its performance. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 911–915, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23236
Coplanar antenna array design with stubs over dipoles for RFID applications
Authors: e Silva F. R. L. , de Melo M. T. , Lourenço M. D. 
Published: February 2008

AbstractA new Coplanar Strip Antenna design is presented. This antenna is suitable for RFID tags, operating in the 2.4‐GHz range. Device was fabricated on RT6002 substrate of thicknessh= 1.5 mm. The input impedance control is based on the conformal mapping technique. A full‐wave EM simulator was used to obtain the frequency response. Simulated and experimental results are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 877–879, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23238
A novel divide‐by‐3 Hartley injection‐locked frequency divider
Authors: Lee Chien‐Feng , Jang Sheng‐Lyang 
Published: February 2008

AbstractThis study proposes a new divide‐by‐3 CMOS injection locked frequency divider (ILFD) fabricated in a 0.18‐μm CMOS process and describes the operation principle of the ILFD. The ILFD circuit is realized with a Hartley CMOS LC‐tank oscillator with two injection MOSFETs. The self‐oscillating VCO is injection‐locked by third‐harmonic input to obtain the division order of three. Measurement results show that at the supply voltage of 1.5 V, the free‐running frequency is from 3.86 to 4.27 GHz. At the incident power of 6 dBm, the locking range is from the incident frequency 12.13–12.86 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 906–909, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23242
Modified maximally flat parallel‐coupled lines for band‐pass filter applications and miniaturizations
Authors: Liu Ji‐Chyun , Zeng Bing‐Hao , Chang Jun‐Mao , Chien Chi‐Hsun , Chang Chung‐Chi , Chang Dau‐Chyrh 
Published: February 2008

AbstractThe modified configurations of maximally flat parallel‐coupled lines (MF‐PCL) structure are introduced to improve the performance of the conventional MF‐PCL resonator. To obtain a higher rejection (−39 dB), symmetry response, wider band (BW about 32%), and less insertion loss (−0.4 dB) filters at central frequency 5.78 GHz, the modified MF‐PCL resonators by using enhanced coupling techniques are proposed herein. The size reduction of 50% is achieved. Results including surface current distributions and frequency responses are presented and discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 902–906, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23243
Portable biometric system of high‐sensitivity absorption detection
Authors: Chen Der‐Chin 
Published: February 2008

AbstractThe purpose of this paper is to design a portable biometric system that can measure the amount of absorption of the visible collimated beam that passes by the sample to know the absorbance of the sample. The measured object in the system is the gold colloid that the sample produces after a biochemical reaction. After measuring the absorbance of the gold colloid, we can obtain the concentrations of the waiting‐measured sample and further obtain the concentration of chemical solution contained in the sample. Normal single optical path system has a sensitivity of 0.5%.The process of the double optical path method increases the opportunities that the visible collimated beam is absorbed, which raise the detection sensitivity of the system to a sensitivity of 0.1%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 868–871, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23249
Closed‐form expressions for computation of mutual admittance of a class of gap‐coupled circular microstrip antennas
Authors: Chakravarty T. , Khah Sunil K. , De Asok 
Published: February 2008

AbstractIn this paper, a new set of expressions are presented, which leads to accurate estimation of the mutual admittance and mutual coupling thereof for gap‐coupled circular microstrip antennas. Unlike previous works, the field expressions for both the patches are obtained with respect to one coordinate system, and the circuit theory is used to obtain the admittance parameter. When this mutual admittance is converted to scattering parameters, we obtain the magnitude of mutual coupling. The results presented in the standard literature are compared with those obtained through the present formulation and the accuracy obtained is reasonably good. The method is also extended to incorporate the effects of shorting pins at the center of the two patches. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 924–927, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23251
A sectoral horn antenna based on the electromagnetic band‐gap structures
Authors: Zhao Zeyu , Deng Qiling , Xu Huiliang , Du Chunlei , Luo Xiangang 
Published: February 2008

AbstractRecently, the electromagnetic band‐gap (EBG) material, also known as photonic crystals, has been successfully used to suppress surface‐wave for the patch antenna. In this article, a sectoral horn antenna with the mushroom‐like EBG material is designed to enhance its gain. A flange plate is attached to the horn antenna mouth and a mushroom‐like EBG material is sticked to the flange plate. Because of effective surface‐wave suppression, the simulant and test results show that the gain of this sectoral horn antenna has almost increased 1.0 dB within the frequency from 11.7 to 14.0 GHz. This kind of horn antenna has the potential application in mobile and satellite communications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 965–969, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23254