bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of an acyclic diselenodithioether ligand tethered with bulky substituents and its application to the synthesis of a distorted octahedral palladium(II) complex
Authors: Takeda Nobuhiro , Isobe Toru , Tokitoh Norihiro 
Published: July 2007

AbstractA newo‐phenylene‐bridged diseleno‐dithioether ligand tethered with an extremely bulky substituent, 2,4,6‐tris[bis(trimethylsilyl)‐methyl]phenyl (Tbt) group, at both terminal selenium atoms, [TbtSe(o‐phenylene)S]2(o‐phenylene) (3), was synthesized by taking advantage of the reaction of TbtSeSeTbt (4) with 1,2‐diiodobenzene using Cu2O in 2,4,6‐trimethylpyridine followed by the successive coupling reaction of the resulting bulkyo‐iodophenylselenide (5) with 1,2‐benzenedithiol. Complexation of3with Na2PdCl4gave the corresponding dichloropalladium(II) complex, [PdCl2(3)] (6). The X‐ray structural analysis of6indicated that the central palladium metal is in a distorted octahedral environment, where the two inner sulfur atoms of3and the two chlorine atoms form a square planar arrangement around the palladium metal and the two terminal selenium atoms of3weakly coordinate to the palladium center at the axial positions. The AIM calculations also indicated the existence of the interaction between palladium and selenium atoms in the crystalline state. On the other hand, the77Se NMR spectrum suggests that there are no or very weak interactions between the palladium and selenium atoms of3in solution. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:549–556, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20339
Stereocontrolled reactions mediated by remote sulfoxides: Formation and reactivity of enantiomerically pure benzylic centers
Authors: García Ruano José Luis , Martín Castro Ana M. 
Published: July 2007

AbstractReactions of different electrophiles (alkyl halides, aldehydes, N‐sulfinylimines, imines, etc) with (S)‐2‐p‐toluenesulfinyl toluene and their alkyl, triisopropylsilyloxy, and methylthio derivatives at benzylic position, in the presence of LDA, allow the synthesis of a variety of enantiomerically pure benzylic centers, whose configuration is efficiently controlled by the γ‐sulfinyl group, according to 1,4‐asymmetric induction processes. With prochiral electrophiles, the 1,5‐asymmetric induction processes can also be controlled either by modifying their steric or electronic features or by incorporating an additional chiral center at the electrophiles. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:537–548, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20342
Silyl thioacetals: Versatile building blocks for organic synthesis
Authors: Schaumann Ernst 
Published: July 2007

AbstractSilyl thioacetals have been shown to allow entry into the chemistry of silyl(arythio) carbenes. Moreover, silyl thioacetals are successful reaction components in the homo‐Peterson cyclopropane synthesis, and, via 1,4‐silyl migration, in the domino synthesis of larger carbocyclic and of heterocyclic rings. Finally, the application of thioacetal‐based silyl migration in the synthesis of acyclic systems is discussed. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:600–608, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20344
Dieldrin elicits a widespread DNA repair and antioxidative response in mouse brain
Authors: Sava Vasyl , Velasquez Adriana , Song Shijie , Sanchez‐Ramos Juan 
Published: July 2007

AbstractDieldrin is an organochlorine pesticide that is toxic for monoaminergic neurons. This study was designed to test the hypothesis that a weak DNA repair response to dieldrin by nigrostriatal dopaminergic (DA) neurons results in depletion of striatal DA. The activity of the mammalian base excision repair enzyme oxyguanosine glycosylase was utilized as the index of DNA repair. Other measures of oxidative stress were also studied, including the regional distribution of lipid peroxidation and superoxide dismutase (SOD) activity. The effects of acute and slow infusion of dieldrin on striatal DA levels were biphasic with a transient initial depression followed by increases beyond normal steady‐state levels. Dieldrin administration caused a global oxidative stress evidenced by increased levels of lipid peroxidation in all brain regions, an effect consistent with its capacity to affect mitochondrial bioenergetics. Dieldrin also elicited strong antioxidative and DNA repair responses across the entire mouse brain. Although mitochondrial SOD was not as increased in midbrain as it was in other regions following a cumulative dose of 24 mg/kg, this response, along with the robust DNA repair response, appeared to be sufficient to protect potentially vulnerable DA neurons from cytotoxicity. However, the long‐term consequences of chronic low‐dose dieldrin exposure remain to be studied, especially in light of the concept of “slow excitotoxicity,'' which postulates that even a mild bioenergetic compromise can over time result in the demise of neurons. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:125–135, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20165
Catechin as an antioxidant in liver mitochondrial toxicity: Inhibition of tamoxifen‐Induced protein oxidation and lipid peroxidation
Authors: Tabassum Heena , Parvez Suhel , Rehman Hasibur , Banerjee Basu Dev , Raisuddin Sheikh 
Published: July 2007

AbstractTamoxifen (TAM) is a nonsteroidal triphenylethylene antiestrogenic drug widely used in the treatment and prevention of breast cancer. TAM brings about a collapse of the mitochondrial membrane potential. It acts both as an uncoupling agent and as a powerful inhibitor of mitochondrial electron transport chain. The effect of catechin pretreatment on the mitochondrial toxicity of TAM was studied in liver mitochondria of Swiss albino mice. TAM treatment caused a significant increase in the mitochondrial lipid peroxidation (LPO) and the protein carbonyls (PCs). It also caused a significant increase in superoxide radical production. Pretreatment of mice with catechin (40 mg/kg) showed significant protection as demonstrated by marked attenuation of increased oxidative stress parameters such LPO, PCs, and superoxide production. It also restored the decreased nonenzymatic and enzymatic antioxidants of mitochondria. The inhibitory effect of catechin on TAM‐induced oxidative damage suggests that it may have potential benefits in prevention of human diseases where reactive oxygen species have some role as causative agents. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:110–117, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20167
Oxidative stress and damage in liver, but not in brain, of fischer 344 rats subjected to dietary iron supplementation with lipid‐soluble [(3,5,5‐trimethylhexanoyl)ferrocene]
Authors: Lykkesfeldt Jens , Morgan Evan , Christen Stephan , Skovgaard Lene Theil , Moos Torben 
Published: July 2007

AbstractAccumulation of iron probably predisposes the aging brain to progressive neuronal loss. We examined various markers of oxidative stress and damage in the brain and liver of 3‐ and 24‐month‐old rats following supplementation with the lipophilic iron derivative {(3,5,5‐trimethylhexanoyl)ferrocene} (TMHF), which is capable of crossing the blood–brain barrier. At both ages, iron concentration increased markedly in the liver but failed to increase in the brain. In the liver of TMHF‐treated young rats, levels of α‐ and γ‐tocopherols and glutathione (GSH) were also higher. In contrast, the brain displayed unaltered levels of the tocopherols and GSH. Malondialdehyde (MDA) level was also higher in the cerebrospinal fluid (CSF) and the liver but not in the brain. In old rats, the absence of an increase in iron concentration in the brain was reflected by unaltered concentrations of GSH, tocopherols, and MDA as compared to that in untreated rats. In the aging liver, concentrations of GSH and MDA increased with TMHF treatment. Morphological studies revealed unaltered levels of iron, ferritin, heme oxygenase‐1 (HO‐1), nitrotyrosine (NT), or MDA in the brains of both young and old rats treated with TMHF. In contrast, TMHF treatment increased the level of HO‐1 in Kupffer cells, NT in hepatic endothelial cells, and MDA and ferritin in hepatocytes. Although these results demonstrated an increase in the biochemical markers of oxidative stress and damage in response to increasing concentrations of iron in the liver, they also demonstrated that the brain is well protected against dietary iron overload by using iron in a lipid‐soluble formulation. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:145–155, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20170
Toxicities induced in cultured cells exposed to zearalenone: Apoptosis or mutagenesis?
Authors: Ayed‐Boussema Imen , Ouanes Zouhour , Bacha Hassen , Abid Salwa 
Published: July 2007

AbstractZearalenone (ZEN) is a fusarotoxin produced mainly by Fusarium graminearum in temperate and warm countries. ZEN has several adverse effects on humans and animals. It has a strong estrogenic activity associated with hyperestrogenism and leads to several physiological alterations in the reproductive tract. Even though the mutagenic and genotoxic proprieties of ZEN have been described recently, its molecular mechanisms of action are not completely understood. The aim of this study was to determine the involvement of other possible mechanisms in ZEN‐induced toxicities. Each of the following toxicities, cytotoxicity, cell cycle perturbation, genotoxicity, and mutagenicity, was monitored in Vero cells exposed to ZEN. Our results showed that ZEN‐reduced cell viability correlated to cell cycle perturbation–induced DNA fragmentation, resulting in DNA‐laddering patterns on agar gel electrophoresis. This observation is consistent with apoptosis, which was confirmed by induction of apoptotic bodies. Moreover, ZEN induced in a concentration‐dependant manner the formation of micronuclei and chromosome aberrations. This apparent contradiction between the apoptotic and mutagenic effects of ZEN can be explained by the modification of normal cellular regulation inducing apoptotic or antiapoptotic factors resulting from a lack of or an incorrect DNA‐reparation in relation to cell exposure to the toxin. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:136–144, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20171
Race, language, and mental evolution in Darwin's descent of man
Authors: Alter Stephen G. 
Published: July 2007

AbstractCharles Darwin was notoriously ambiguous in his remarks about the relationship between human evolution and biological race. He stressed the original unity of the races, yet he also helped to popularize the notion of a racial hierarchy filling the gaps between the highest anthropoids and civilized Europeans. A focus on Darwin's explanation of how humans initially evolved, however, shows that he mainly stressed not hierarchy but a version of humanity's original mental unity. In his book The Descent of Man, Darwin emphasized a substantial degree of mental development (including the incipient use of language) in the early, monogenetic phase of human evolution. This development, he argued, necessarily came before primeval man's numerical increase, geographic dispersion, and racial diversification, because only thus could one explain how that group was able to spread at the expense of rival ape‐like populations. This scenario stood opposed to a new evolutionary polygenism formulated in the wake of Darwin's Origin of Species by his ostensible supporters Alfred Russel Wallace and Ernst Haeckel. Darwin judged this outlook inadequate to the task of explaining humanity's emergence. © 2007 Wiley Periodicals, Inc.
Francis bacon's behavioral psychology
Authors: Macdonald Paul S. 
Published: July 2007

AbstractFrancis Bacon offers two accounts of the nature and function of the human mind: one is a medical‐physical account of the composition and operation of spirits specific to human beings, the other is a behavioral account of the character and activities of individual persons. The medical‐physical account is a run‐of‐the‐mill version of the late Renaissance model of elemental constituents and humoral temperaments. The other, less well‐known, behavioral account represents an unusual position in early modern philosophy. This theory espouses a form of behavioral psychology according to which (a) supposed mental properties are “hidden forms” best described in dispositional terms, (b) the true character of an individual can be discovered in his observable behavior, and (c) an “informed” understanding of these properties permits the prediction and control of human behavior. Both of Bacon's theories of human nature fall under his general notion of systematic science: his medical‐physical theory of vital spirits is theoretical natural philosophy and his behavioral theory of disposition and expression is operative natural philosophy. Because natural philosophy as a whole is “the inquiry of causes and the production of effects,” knowledge of human nature falls under the same two‐part definition. It is an inquisition of forms that pertains to the patterns of minute motions in the vital spirits and the production of effects that pertains both to the way these hidden motions produce behavioral effects and to the way in which a skillful agent is able to produce desired effects in other persons' behavior. © 2007 Wiley Periodicals, Inc.
Measurement of signal‐to‐noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters
Authors: Dietrich Olaf , Raya José G. , Reeder Scott B. , Reiser Maximilian F. , Schoenberg Stefan O. 
Published: July 2007

AbstractPurposeTo evaluate the validity of different approaches to determine the signal‐to‐noise ratio (SNR) in MRI experiments with multi‐element surface coils, parallel imaging, and different reconstruction filters.Materials and MethodsFour different approaches of SNR calculation were compared in phantom measurements and in vivo based on: 1) the pixel‐by‐pixel standard deviation (SD) in multiple repeated acquisitions; 2) the signal statistics in a difference image; and 3) and 4) the statistics in two separate regions of a single image employing either the mean value or the SD of background noise. Different receiver coil systems (with one and eight channels), acquisitions with and without parallel imaging, and five different reconstruction filters were compared.ResultsAveraged over all phantom measurements, the deviations from the reference value provided by the multiple‐acquisitions method are 2.7% (SD 1.6%) for the difference method, 37.7% (25.9%) for the evaluation of the mean value of background noise, and 34.0% (38.1%) for the evaluation of the SD of background noise.ConclusionThe conventionally determined SNR based on separate signal and noise regions in a single image will in general not agree with the true SNR measured in images after the application of certain reconstruction filters, multichannel reconstruction, or parallel imaging. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Balanced steady‐state free precession vs. segmented fast low‐angle shot for the evaluation of ventricular volumes, mass, and function at 3 Tesla
Authors: Grothues Frank , Boenigk Hagen , Graessner Joachim , Kanowski Martin , Klein Helmut U. 
Published: July 2007

AbstractPurposeTo compare balanced steady‐state free precession (SSFP) and segmented fast low angle shot (FLASH) for quantification of left and right ventricular volumes and function and for left ventricular mass at high field (3 Tesla).Materials and MethodsA total of 33 patients (19 male, mean age 54 years) with various forms of heart disease underwent ventricular function studies using cine SSFP and FLASH sequences with identical slice orientations.ResultsUsing SSFP, left ventricular end‐diastolic (+10 mL [4.7%], P < 0.001) and end‐systolic volumes (+9 mL [6.1%], P < 0.001) measured larger whereas mass was considerably smaller (–23 g [–12.9%], P < 0.001) and ejection fraction (–1% [–3.2%], P < 0.01) marginally smaller. Right ventricular end‐diastolic (+4 mL [2.6%], P = 0.001) and end‐systolic volumes (+4 mL [5.1%], P < 0.01) were also larger, but no significant difference for right ventricular ejection fraction (P = 0.05) was found.ConclusionSimilar to previous results at 1.5 Tesla, at high magnetic field the cine SSFP technique led to discrete but significantly higher ventricular volume measurements and to a significantly smaller measurement of left ventricular mass in patients. The effect on left and right ventricular ejection fraction was minor, although the difference remained significant for the left ventricle. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Inflammatory myofibroblastic tumors in the liver: MRI of two immunohistochemically‐verified cases
Authors: Yu Jeong‐Sik , Park Chanil , Kim Joo Hee , Chung Jae‐Joon , Kim Ki Whang 
Published: July 2007

AbstractIn immunohistochemically‐proven hepatic inflammatory myofibroblastic tumors, MRI revealed layered patterns of contrast enhancement during dynamic imaging, consisting of outer hypovascular rind and inner hypervascular stroma and mimicking the imaging features of pyogenic organized abscess with deficient central necrosis in four lesions in two patients. For the outer hypovascular rind, T2‐weighted images showed hyperintensity, suggesting immature fibrosis corresponding to the area of arterial hypovascularity and delayed contrast enhancement. The patients' favorable clinical course and imaging findings reflected the benign nature of these lesions, from an infectious origin, despite the phenotypic expression of myofibroblastic proliferation in the hypervascular stroma containing chronic inflammatory cells. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Angiotensin converting enzyme inhibition of fish protein hydrolysates prepared from alkaline‐aided channel catfish protein isolate
Authors: Theodore Ann E , Kristinsson Hordur G 
Published: July 2007

AbstractPeptides derived from aquatic animals have been shown to have inhibitory activity against angiotensin converting enzyme (ACE), which is a key enzyme behind elevated blood pressure. In this study a catfish protein isolate was prepared and hydrolyzed to 5%, 15% and 30% degrees of hydrolysis (% DH) and soluble peptides separated from the total hydrolysate. The hydrolysate and its soluble peptide fraction were studied separately. Increased hydrolysis produced smaller peptides, with the smallest peptides remaining in the soluble fraction. Both hydrolysates and its soluble fraction had high ACE inhibition activities, from 70% to 90.6%, depending on fraction and % DH. Results suggested that there is not a simple relationship between average peptide size and extent of % DH and ACE inactivation, but clearly the soluble fraction of the hydrolysate, containing the smallest peptides, is responsible for most of the ACE inhibition activity of the hydrolysate. Hydrolysates prepared from a pure and uniform catfish protein isolate substrate do therefore show a potential for ACE inhibition and may find use as bioactive ingredients. Copyright © 2007 Society of Chemical Industry
A new shallow water model with polynomial dependence on depth
Authors: Rodríguez José M. , Taboada‐Vázquez Raquel 
Published: July 2007

AbstractIn this paper, we study two‐dimensional Euler equations in a domain with small depth. With this aim, we introduce a small non‐dimensional parameter ε related to the depth and we use asymptotic analysis to study what happens when ε becomes small.We obtain a model for ε small that, after coming back to the original domain, gives us a shallow water model that considers the possibility of a non‐constant bottom, and the horizontal velocity has a dependence onzintroduced by the vorticity when it is not zero. This represents an interesting novelty with respect to shallow water models found in the literature. We stand out that we do not need to makea prioriassumptions about velocity or pressure behaviour to obtain the model.The new model is able to approximate the solutions to Euler equations with dependence onz(reobtaining the same velocities profile), whereas the classic model just obtains the average velocity. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of parasitic components of GaAs FETs on high‐frequency gain
Authors: Seo Youngseok , Kim Bumman , Park Wee Sang 
Published: July 2007

AbstractParasitic component effects on the gain of GaAs FETs are described. Numerical simulation shows that the frequency range of the unstable region (K < 1) of an FET decreases as gate resistance, drain resistance, or source inductance increases, and as source resistance decreases. The increase of gate or drain resistance does not affect MSG but does reduce MAG. The increase of source inductance or resistance reduces MSG and MAG. The Mag degradation is due to the decrease of |y21/y12| for the source resistance and the increase of K for the other parasitics. These findings should be helpful in the design and analysis of microwave GaAs FETS. © 1993 John Wiley & sons, Inc.
A CG‐FFHT method for the scattering solution of axisymmetric inhomogeneous media
Authors: Liu Qing‐Huo , Chew Weng Cho 
Published: July 2007

AbstractWe propose a new technique to solve the integral equation for wave scattering by an axisymmetric inhomogeneity using the conjugate gradient (CG) method together with the fast Fourier‐Hankel transforms (FFHT). The method uses fast Hankel transform (FHT) and fast Fourier transform (FFT) requiring only O(N log N) floatingpoint operations per iteration and O(N) storage. © 1993 John Wiley & sons, Inc.
Spectral‐domain moment‐method analysis of coplanar microstrip parasitic subarrays
Authors: Chen Wei , Lee Kai‐Fong , Lee R. Q. 
Published: July 2007

AbstractCoplanar subarrays consisting of one fed patch and two or more parasitic patches are studied using spectral‐domain full‐wave analysis and the moment method. Results are given for three‐element linear subarrays and the five‐patch cross. © 1993 John Wiley & sons, Inc.
Conditions of perfect absorption for a single‐layer electromagnetic‐wave absorber under oblique incidence
Authors: Liang C. H. , Zhao X. Y. 
Published: July 2007

AbstractThe conditions for perfect absorption under oblique incidence in a single‐layer homogeneous absorber backed by a perfectly conducting plate are derived in this article. The cases corresponding to the two types of polarization of the incidence‐wave, perpendicular polarization (TE) and parallel polarization (TM), are discussed, respectively. Some conclusions and curves are given. © 1993 John Wiley & sons, Inc.
A coaxial test fixture for characterizing low‐impedance microwave two‐terminal devices
Authors: Monahan Gregory P. , Morris Arthur S. , Steer Michael B. 
Published: July 2007

AbstractA technique using a coaxial diode test fixture for the mount‐independent characterization of potentially unstable two‐terminal devices is presented. A standard three‐terminal calibration procedure using reference packages is used to calibrate to the surface of the packaged device. The test fixture is designed to present a low, nonresonant impedance to the device so that measurement resolution is enhanced. The characterization of an IMPATT diode is presented as an example. © 1993 John Wiley & sons, Inc.
On the time‐domain response of microstrip dipoles embedded in a low‐loss grounded dielectric slab
Authors: Cicchetti Renato 
Published: July 2007

AbstractA space‐time analysis of the field radiated from microstrip dipoles embedded in a low‐loss grounded dielectric slab is proposed. The analysis is based on the dyadic Green's function method. The radiation mechanism as well as the structure electrical and geometrical parameters influencing the radiation phenomenon are analyzed. Design guidelines to reduce the amplitude of the radiated field, or its distortion, are suggested. © 1993 John Wiley & sons, Inc.