bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Evaluation of Anticonvulsant and Antimicrobial Activities of 3‐Hydroxy‐6‐methyl‐2‐substituted 4H‐Pyran‐4‐one Derivatives
Authors: Aytemir Mutlu Dilsiz , Çaliş Ünsal , Özalp Meral 
Published: April 2004

AbstractIn this study, thirteen 3‐hydroxy‐6‐methyl‐2‐substituted 4H‐pyran‐4‐one derivatives were synthesized for the evaluation of their potential anticonvulsant activity. Mannich bases were prepared by the reaction of substituted piperazine derivatives with allomaltol and formaline. The structures of the synthesized compounds were confirmed by IR, 1H‐NMR and elemental analysis. Their anticonvulsant activities were determined in vivo by maximal electroshock (MES), sub‐cutaneous Metrazol (scMet), and rotorod toxicity tests for neurological deficits. The antimicrobial activities of the synthesized compounds were investigated in vitro against some bacteria and fungi using the microdilution broth method. Ac‐cording to the activity studies, 3‐hydroxy‐6‐methyl‐2‐[4‐(2‐trifluoromethyl‐phenyl)‐piperazin‐1‐ylmethyl]‐4H‐pyran‐4‐one (3i) was the compound determined to be most active in the scMet test for all doses at four hours and for the 300 mg/kg dose at half an hour. 2‐[4‐(4‐Chloro‐phenyl)‐piperazin‐1‐ylmethyl]‐3‐hydroxy‐6‐methyl‐4H‐pyran‐4‐one (3f) was found to be protective against MES whereas 2‐chlorophenyl derivative (3e) was not. Looking at the antifungal activity results, compounds 3b, 3h, and 3i were determined to have activity against all fungi.
Novel Antiprotozoal Products: Imidazole and Benzimidazole N‐Oxide Derivatives and Related Compounds
Authors: Aguirre Gabriela , Boiani Mariana , Cerecetto Hugo , Gerpe Alejandra , González Mercedes , Sainz Yolanda Fernández , Denicola Ana , de Ocáriz Carmen Ochoa , Nogal Juan José , Montero David , Escario José Antonio 
Published: April 2004

AbstractThe syntheses and biological evaluation of the first anti‐protozoa imidazole N‐oxide and benzimidazole N‐oxide and their derivatives are reported. They were tested in vitro against two different protozoa, Trypanosoma cruzi and Trichomonas vaginalis. Derivative 7c, ethyl‐1‐(i‐butyloxycarbonyloxy)‐6‐nitrobenzimid‐azole‐2‐carboxylate, displayed activity on both protozoa. Lipophilicity and redox potential were experimentally determined in order to study the relationship with activity of the compounds. These properties are well related with the observed bioactivity. Imidazole and benzimidazole N‐oxide derivatives are becoming leaders for further chemical modifications and advanced biological studies.
Aging properties of the residual life length of k‐out‐of‐n systems with independent but non‐identical components
Authors: Li Xiaohu , Chen Jing 
Published: April 2004

AbstractThe k‐out‐of‐n structure is a very popular type of redundancy in fault‐tolerant systems, it has founded wide applications in industrial and military systems during the past several decades. This paper will investigate the residual life length of a k‐out‐of‐n system with independent (not necessarily identical) components, given that the (n−k)th failure has occurred at time t⩾0. Behaviour of PF2, IFR, DRHR, DMRL, NBU(2) and NBUC classes of life distributions are derived in terms of the monotonicity of the residual life given the time of the (n−k)th failure. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of the CuA center in the cytochrome c oxidase from Thermus thermophilus for the spectral range 1800–500 cm−1 with a combined electrochemical and Fourier transform infrared spectroscopic setup
Authors: Wolpert M. , Maneg O. , Ludwig B. , Hellwig P. 
Published: April 2004

AbstractIn this study we present the electrochemically induced Fourier transform infrared (FTIR) difference spectra of the CuA center derived from the ba3‐type cytochrome c oxidase of Thermus thermophilus in the spectral range from 1800 to 500 cm−1. The mid infrared is dominated by the ν(CO) vibrations of the amide I modes at 1688, 1660, and 1635 cm−1, reflecting the redox‐induced perturbation of the predominantly β‐sheet type structure. The corresponding amide II signal is found at 1528 cm−1. In the lower frequency range below 800 cm−1, modes from amino acids liganding the CuA center are expected. On the basis of the absorbance spectrum of the isolated amino acids, methionine is identified as an important residue, displaying C—S vibrations at these frequencies. This spectral range was previously disregarded by protein IR spectroscopists, mainly due to the strong absorbance of the solvent, H2O. With an optimized setup, however, IR is found suitable for structure/function studies on proteins. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Exogenous compounds in studying the mechanism of electron‐excited state formation in bioluminescence
Authors: Kudryasheva N. S. , Nemtseva E. V. , Kirillova T. N. 
Published: April 2004

AbstractUsing a series of exogenous fluorescent molecules as potential energy acceptors, the hypothesis on the activity of the upper electron‐excited states in bioluminescence was tested. The results in bacterial and firefly bioluminescent enzyme systems were compared. Similar activity to the energetic precursor in bacterial bioluminescence was not proven in the case of the firefly system, the result of a very efficient intramolecular energy transfer in the emitter of the firefly bioluminescence. The influence of a number of metallic salts on a bacterial bioluminescent enzyme system was studied. Bioluminescence inhibition coefficients were compared to the free energies of electron withdrawing of cations. The correlation shows that inhibition and activation of luminescence intensity result from the effects of cations on electron transfer in the bioluminescent system. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Fast relaxation processes and structural changes in immunoactive biomolecules
Authors: Borisevich N. A. , Dubovsky V. L. , Mikhalchuk A. L. , Raichyonok T. F. , Tikhomirov S. A. , Tolstorozhev G. B. 
Published: April 2004

AbstractBased upon an analysis of the absorption spectra, the fluorescence and fluorescence excitation spectra, and the lifetime of the excited states of aqueous solutions (pH 7.4) of 2,3‐dimethoxy‐8‐azagona‐1,3,5(10),13‐tetraene‐12,17‐dione, it is established that two centers of different type exist: one emits long‐wave (L‐centers) and the other short‐wave (S‐centers) fluorescence. Irradiation of solutions increases the number of L‐centers and greatly decreases that of S‐centers. Examination of the picosecond transient absorption spectra and their kinetics revealed that the initial photochemical stage is defined as the ionization of a considered molecule and the subsequent one, as the formation, most probably, of the dehydroderivative of a parent molecule. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Sentinel lymph node detection in primary melanoma with preoperative dynamic lymphoscintigraphy and intraoperative γ probe guidance
Authors: Tiffet O , Perrot J L , Gentil-Perret A , Prevot N , Dubois F , Alamartine E , Cambazard F 
Published: April 2004

Abstract

Background
This study assessed the value of the radioisotopic method used alone, and factors influencing relapse rates, for sentinel lymph node (SLN) mapping in primary melanoma.

Methods
One hundred and thirty-three patients with a diagnosis of melanoma (thickness greater than 0·75 mm) underwent γ probe-directed lymphatic mapping in a prospective single-centre study.

Results
Mean Breslow thickness was 3 mm. At least one SLN was identified in 132 patients (mean 1·8 nodes per patient); the success rate was 99·2 per cent. Twenty-two patients (16·7 per cent) had a metastasis within the SLN. The mean tumour thickness in patients with a metastatic SLN was 4·4 mm compared with 2·7 mm for patients with a negative SLN (P &lt; 0·001). The median time to recurrence was 20·4 months in SLN-negative patients compared with 8·5 months in those with SLN metastasis (P &lt; 0·001). Ten (9·1 per cent) of the 110 SLN-negative patients developed recurrence. Three patients relapsed in the previously mapped lymphatic basin after a median follow-up of 27·1 months.

Conclusion
This study confirmed the reliability and accuracy of SLN mapping using a radioisotope technique, and also the importance of the SLN as a predictive factor for survival. There was a low risk of locoregional recurrence when the SLN was not involved.
Entwicklungen im Waagenbau: Antworten auf die Globalisierung
Authors: Oldendorf Christian 
Published: April 2004

AbstractModerner Waagenbau mit seiner hochentwickelten Funktionalität ist einer hohen Dynamik unterworfen. Was vor 100 Jahren noch in einer technischen Werkstatt entstehen konnte, wird heute in einem ausgeklügelten weltweiten Geflecht gefertigt und zum Kunden gebracht.
Molecular dissection of the fibroblast‐traction machinery
Authors: Sawhney Ravi K. , Howard Jonathon 
Published: April 2004

AbstractMotile fibroblasts generate forces that can be expressed as cell migration or as traction, the drawing‐in of extracellular matrix. Traction by cultured fibroblasts can induce a rapid concerted reorganization of collagen gel, creating a pattern of collagen alignment similar to that seen in tendons and ligaments. In such fibrous connective tissues, after pattern morphogenesis is complete, ongoing traction may be responsible for the maintenance of proper form and function. The molecules that generate and transmit forces have been catalogued; however, how these nanometer‐scale molecules contribute to millimeter‐scale patterns has not been directly tested. Here, we placed pairs of explants of human periodontal ligament fibroblasts in collagen gels, where ligament‐like straps of anisotropic collagen formed on the axes between them. We scrutinized the traction apparatus using electron microscopy, video microscopy, and computer‐based pattern analysis, augmented with pharmacologic inhibitors of cytoskeletal function. Patterning was marked by the co‐alignment of collagen, fibroblasts, and their actin cytoskeletons, all parallel to the axis between explants. The pattern was diminished by depolymerizing actin filaments or by blocking myosin activity, but was accentuated by depolymerizing microtubules. The plasma membrane also seems to contribute to the traction force. These molecular components combine to exert a sub‐maximal traction force on the matrix, suggesting that the force may be regulated to ensure tissue tensional homeostasis. Cell Motil. Cytoskeleton 58:175–185, 2004. © 2004 Wiley‐Liss, Inc.
The development of interval breast malignancies in patients with BRCA mutations
Authors: Komenaka Ian K. , Ditkoff Beth‐Ann , Joseph Kathie‐Ann , Russo Donna , Gorroochurn Prakash , Ward Marie , Horowitz Elizabeth , El‐Tamer Mahmoud B. , Schnabel Freya R. 
Published: April 2004

AbstractBACKGROUNDAt present, there is no consensus regarding how frequently BRCA mutation carriers should be screened for malignancies using breast imaging techniques. An interval malignancy is defined as a malignancy that becomes evident during the period between annual screening mammography scans; the finding of such a malignancy indicates that the malignancy either went undetected by the last breast imaging scan or developed during the interval since that last scan.METHODSThe authors retrospectively reviewed the medical charts of all BRCA mutation carriers who were followed by the genetic counselor at the Columbia‐Presbyterian Comprehensive Breast Center (New York, NY) between September 1995 and September 2002.RESULTSThirteen BRCA mutation carriers elected to undergo close surveillance and thus were followed at our institution. Three of these 13 patients (23%) did not develop breast carcinoma, 4 (31%) developed breast carcinoma that was detected at the time of annual screening, and 6 (46%) developed palpable interval malignancies in less than 12 months. Among the six patients who developed interval malignancies, the mean time between the last screening mammogram and disease presentation was 5.1 months (range, 2–9 months); the average tumor size in this patient subgroup was 1.7 cm (range, 0.8–3 cm). Two of these six patients had ductal carcinoma in situ, whereas the remaining four had invasive breast carcinoma; three patients had positive lymph nodes at presentation. All six patients who developed interval disease exhibited dense breast tissue on the previous mammogram. Focused breast ultrasonography was able to identify the tumor mass in 3 of 4 patients (75%).CONCLUSIONSNearly half of all BRCA‐positive women who chose to undergo close surveillance in the current study developed malignant disease less than a year after exhibiting normal findings on screening mammography. Half of these interval malignancies were positive for lymph node involvement. These results suggest that strong consideration should be given to screening BRCA‐positive women at more frequent intervals and to using additional imaging techniques, such as breast ultrasonography and/or breast magnetic resonance imaging, as a part of this screening. Cancer 2004. © 2004 American Cancer Society.
Analysis of random access channel in UTRA‐TDD on AWGN channel
Authors: Yang Yang , Yum Tak‐Shing Peter 
Published: April 2004

AbstractThe random access channel (RACH) in UTRA‐TDD systems is an uplink contention‐based transport channel that is mainly used to carry control information from mobile stations to base stations. In this paper, we study the performance of RACH on an additive white Gaussian noise (AWGN) channel whereby successful transmission of a burst requires the spreading code chosen to be collision‐free and the burst is error‐free after convolutional decoding. Based on this model, the code‐collision probability, the data bit error probability and the RACH channel capacity are derived. The random retransmission delay mechanism is not specified in UTRA‐TDD. We therefore choose an access mechanism with binary exponential backoff delay procedure similar to that in IEEE 802.11. Based on that mechanism, the blocking probability and the first two moments of the delay are also derived. Compared with the mean, the standard deviation is found to be very high. Copyright © 2004 John Wiley & Sons, Ltd.
An entropy estimator improving mean squared error
Authors: Yokota Yasunari , Shiga Motoki 
Published: April 2004

AbstractEntropy estimation for a memory‐less information source has mainly been performed by the following process under the condition that the occurrence probability of each source symbol is unknown: First, the occurrence probabilities of source symbols are estimated; then the entropy is estimated by substituting the estimated occurrence probabilities into the entropy function. Such an entropy estimation is not optimum in the sense of least squares error; it causes a large error, particularly for small sample size. In this paper, we propose an entropy estimator that strictly minimizes the mean squared error for a two‐ary memory‐less information source; it is formulated as a function of the number of one type of source symbols contained in the sample set. Furthermore, we propose a technique for estimating entropy of an arbitrary M‐ary memory‐less information source by recursively applying the proposed entropy estimator for a two‐ary memory‐less information source. Numerical experiments show that this technique improves mean squared error compared to the conventional method even though the guarantee that it is the least squares error estimator has been lost. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(9): 1–10, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10163
A watermarking scheme without reference images for broadcast monitoring
Authors: Tachibana Takashi , Fujiyoshi Masaaki , Kiya Hitoshi 
Published: April 2004

AbstractIn this paper, to automate broadcast monitoring, which is typified by the verification of the transmission of the material ID code of a commercial message (CM) or program, the authors propose a watermarking scheme without reference images, which does not require a reference image when the watermark sequence is extracted. By embedding a watermark sequence formed by using standard normal random numbers after discretizing the embedding‐target coefficients in the DCT domain, the proposed technique makes a reference image unnecessary when the watermark sequence is extracted. In addition, since the proposed technique enables a watermark image having the desired image quality (PSNR) to be achieved for any image, it has the advantage that the image quality can always be maintained regardless of the image. Therefore, the same procedure can always be used to embed the watermark sequence in a full‐motion video image without obtaining parameters for each image and to extract that watermark sequence without using a reference image. The authors used simulations to verify that an image quality of at least 56 dB, which is the HDTV digital VTR guideline, can be maintained even in the watermarked image, that the watermark sequence can be extracted without using a reference image, and that the proposed technique is robust with respect to MPEG. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(9): 22–32, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20101
Fast feedback control of plasma horizontal position by using DSP and IGBT inverter
Authors: Toyoda Mitsuhiro , Kikuchi Yusuke , Uesugi Yoshihiko , Takamura Shuichi 
Published: April 2004

AbstractTo achieve high confinement properties of a tokamak plasma, it is necessary to control the plasma position, current profile, shape of magnetic surface, and so on. In addition, it has been found that a resistive wall mode (RWM) may limit the achievable plasma beta in present tokamak devices. Therefore, it is expected that an active feedback control using external coils is necessary to stabilize the RWM. A power supply for plasma control coils requires an accurate controllability and a fast response against such plasma disturbances. Recent development of high‐power fast‐switching semiconductors, such as Insulated Gate Bipolar Transistor (IGBT) and MOSFET, improves the temporal response of power supply to a great extent. A small tokamak device, HYBTOK‐II, is equipped with IGBT inverter power supplies for Joule and vertical field coils. In this paper a real‐time feedback control of the plasma horizontal position has been employed with a Digital Signal Processor (DSP). The experimental results on plasma response with such a feedback control have been compared with analysis of plasma column motion using transfer functions. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(1): 1–10, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10295
A control strategy for active filters using quasi‐instantaneous positive sequence extraction filters
Authors: Furukawa Kouji , Tarafdar Haque M. , Ise Toshifumi , Kumagai Sadatoshi 
Published: April 2004

AbstractA novel control strategy for active filters, employing quasi‐instantaneous positive sequence extraction of utility voltage, can be useful in harmonic polluted and/or imbalanced utility voltage. In this paper, the authors examined its transient response, its performance under the change of fundamental frequency of utility voltage and its performance under utility voltage with harmonics and unbalance. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(1): 54–65, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10307
A multi‐teacher learning automata computing model for graph partitioning problems
Authors: Ikebo Shigeya , Qian Fei , Hirata Hironori 
Published: April 2004

AbstractGraph partitioning is an important problem that has extensive applications in many areas, including VLSI design, scientific computing, data mining, geographical information systems, and job scheduling. The graph partitioning problem (GPP) is NP‐complete. There are several heuristic algorithms developed for finding a reasonably good solution. The most famous partitioning methods are simulated annealing (SA) and the mean field algorithm (MFA), both known to produce good partitioning for a wide class of problems, and they are used quite extensively. However, these methods are very expensive in terms of time and very sensitive to parameter tuning methods. In this paper, a new parameter‐free algorithm for GPP has been proposed. The algorithm has been constructed using the S‐model learning automata with multi‐teacher random environments. As shown in our experiments, the proposed algorithm has some advantages over SA, MFA, and ParMeTiS. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(1): 46–53, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10310
Characteristics of thin film deposition by photo‐CVD using a Xe2 excimer lamp
Authors: Miyano Junichi , Yokotani Atsushi , Kurosawa Kou 
Published: April 2004

AbstractRecently, a novel method of photochemical vapor deposition using vacuum ultraviolet (VUV) excimer lamps (VUV‐CVD) has been developed. We have been attempting to make thin films from organic precursors at room temperature by VUV‐CVD. We present the characteristics of VUV‐CVD films and the reaction properties of VUV‐CVD as a function of the addition of O2, the substrate temperature, and the illumination intensity, examining the growth rate, film quality, and gap‐filling properties when various organic siloxane gases are used as chemical precursors. VUV photons dissociate the organic precursor and produce radical reactants that consist of Si‐O and impurities such as C‐H and O‐H. They finally condense into deposition films including SiO2 and impurities. Therefore, the VUV‐CVD films are very similar in composition to the precursors. The reaction is altered by adding O2, which produces ozone and activated oxygen as a result of dissociation by VUV photons. The deposition efficiency is improved by both a low substrate temperature and the higher light intensity of the excimer lamp. Film deposition at room temperature in VUV‐CVD without thermal‐ or plasma‐induced damage constitutes an important innovation in thin film preparation. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(4): 43–50, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10325
Prediction of the operational impedance of rotating machines by various DC testing methods
Authors: Yamamoto Shu , Gotou Takashi , Ara Takahiro 
Published: April 2004

AbstractThis paper presents methods to determine the operational impedance of rotating machines by Fourier transformation of the voltage and current measured when a step (or pulse) voltage is applied to the two stator winding terminals. These standstill tests using a small‐capacity DC power supply unit are tentatively termed DC testing methods. We also describe in detail the case using a DC power source with ripple and the case in which a step (or pulse) voltage is applied with current flowing. These methods are applied to a 5.5‐kW squirrel‐cage induction motor having semiclosed rotor slots. The validity of the proposed prediction methods is demonstrated by comparing the calculated and measured speed characteristics of the tested induction machine. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(4): 51–59, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10348