bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zinc Thiolate Complexes [ZnLn(SR)]+ with Azamacrocyclic Ligands, Part II: Mechanism of the Reaction with CS2
Authors: Notni Johannes , Schenk Stephan , Roth Arne , Plass Winfried , Görls Helmar , Uhlemann Ute , Walter Angela , Schmitt Michael , Popp Jürgen , Chatzipapadopoulos Susana , Emmler Thomas , Breitzke Hergen , Leppert Jörg , Buntkowsky Gerd , Kempe Kristian , Anders Ernst 
Published: May 2006

AbstractThe thiolate complexes [Zn([15]aneN4)(S–CH2–C6H5)]ClO4 (1) ([15]aneN4 = 1,4,8,12‐tetraazacyclopentadecane) and [Zn(i‐[14]aneN4)(S–CH2–C6H5)]ClO4 (2) (i‐[14]aneN4 = 1,4,7,11‐tetraazacyclotetradecane) have been reacted with carbon disulfide. The trithiocarbonate complexes [Zn([15]aneN4){S–C(S)–S–CH2–C6H5}]ClO4 {1a, monoclinic, space group P21/n, Z = 8, a = 13.2338(1) Å, b = 12.9251(2) Å, c = 30.1669(4) Å, β = 101.463(1)°, V = 5057.1(1) Å3} and [Zn(i‐[14]aneN4){S–C(S)–S–CH2–C6H5}]ClO4 {2a, orthorhombic, space group P212121, Z = 8, a = 9.9936(1) Å, b = 22.1261(4) Å, c = 22.3192(4) Å, V = 4935.2(1) Å3} were obtained. The reaction of 1 with CS2 is second order with a rate constant of k = (57.6 ± 2.4) × 10–3 M–1·s–1 at 25 °C. The experimentally determined Eyring activation barrier is ΔHexp‡ = 65.3 ± 0.7 kJ·mol–1(ΔSexp‡ = –49.9 ± 2.5 J·mol–1·K–1) and a free energy of activation of ΔG‡ = 80.2 ± 1.5 kJ·mol–1 at 25 °C. To discriminate between an associative and a dissociative mechanism the barriers for both processes were calculated using density functional theory at the C‐PCM(B98/G3MP2Large)//B3LYP/6‐311+G(d) level. The associative mechanism is clearly favored with a difference in free energies of activation ofδΔG‡ ≈ 80 kJ·mol–1. Its calculated barrier ΔGtheor‡ = 114.3 kJ·mol–1 is in reasonable agreement with the experimental value. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Monocyclic 1,2,3‐Triazin‐4(3H)‐ones: Synthesis, Structure and Photochemical Behaviour
Authors: Celli Angela Maria , Ferrini Serena , Ponticelli Fabio 
Published: May 2006

AbstractOxidation of the easily available 1‐(alkylamino)pyrazolones allows the preparation of the title compounds, which are a new class of heterocycles, in good yields. The structure of these compounds is assigned on the basis of HR mass spectroscopy and sodium borohydride reduction to (Z,E)‐2‐methyl‐3‐phenyl‐N‐(1‐phenylethyl)acrylamide. Ring contraction/rearrangement to 2‐alkyl‐2H‐1,2,3‐triazole is observed under UV irradiation. A possible mechanistic rationalisation of the observed processes is proposed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
DNA damage and repair measurements from cryopreserved lymphocytes without cell culture—A reproducible assay for intervention studies
Authors: Chang Jyh‐Lurn , Chen Gang , Lampe Johanna W. , Ulrich Cornelia M. 
Published: May 2006

AbstractSingle‐cell gel electrophoresis (the Comet assay) can be used to measure DNA damage and DNA repair capacity (DRC). However, to test DRC of cryopreserved lymphocytes, published methods include steps for cell culturing and phytohemagglutinin stimulation, which may limit use of this assay in intervention studies. We developed a modified Comet assay protocol that allows us to measure DRC from cryopreserved lymphocytes without these in vitro manipulations. Assay reproducibility was evaluated by performing the assay six times on different dates using six aliquots from one blood draw of one individual. The interindividual variation was assessed by performing the assay using one aliquot from six individuals. When γ‐irradiation was used as the mutagen, intra‐assay coefficients of variation (CVs.) for baseline DNA damage, damage after γ‐irradiation exposure, and DRC—measured as tail moment—were 8, 31, and 10%, respectively. Interindividual CVs. were higher. When H2O2 was used as the mutagen, intra‐assay CVs. for damage measurements were lower for a protocol modification that included damage and repair at 37°C (CVs. ranging from 8 to 35%) than for the more standard 4°C protocol. Analyzing moment arm—the average distance of DNA migration within the tail—yielded similar results. DNA repair was successfully detected in each experiment. Comparing freshly isolated lymphocytes to cryopreserved lymphocytes from the same individuals' blood draw indicated that DRC was highly correlated when determined using moment arm values. This modified protocol extends the use of the Comet assay to measuring DRC in intervention studies (e.g., dietary interventions) in that it assesses cellular response after cryopreservation without cell culture or other extensive manipulation. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Recovery of lactic acid by batch reactive distillation
Authors: Kumar Rakesh , Mahajani Sanjay M , Nanavati Hemant , Noronha Santosh B 
Published: May 2006

AbstractLactic acid, being virtually a non‐boiling compound, is difficult to separate from its aqueous solution by conventional methods such as distillation. It is necessary to convert it to the relatively volatile ester and the separation of the ester, followed by hydrolysis, is recommended as an appropriate method of recovery. In the present work, we explore and investigate a novel reactive distillation strategy to perform esterification, distillation and hydrolysis in a single unit. The experiments were performed in a batch reactive distillation set‐up and the results have been explained with the help of an appropriate model. An unsteady state mathematical model based on an equilibrium stage concept was developed for batch reactive distillation. A pseudo‐homogeneous model was used for the determination of reaction kinetics. The effect of operating parameters such as feed concentration, mole ratio, catalyst loading, boil‐up rate, etc. on the recovery of lactic acid was studied with the help of simulation and experimental results. The feasibility issue of reactive distillation has been discussed based on the results obtained. Copyright © 2006 Society of Chemical Industry
Assessment of a semi‐quantitative method for estimation of the rejection of organic compounds in aqueous solution in nanofiltration
Authors: Van der Bruggen Bart , Verliefde Arne , Braeken Leen , Cornelissen Emile R , Moons Kathleen , Verberk Jasper QJC , van Dijk Hans JC , Amy Gary 
Published: May 2006

AbstractA large number of different mechanisms describing the retention of dissolved organic compounds in nanofiltration have been proposed. A recent review identified the parameters possibly involved in the separation performance and suggested a qualitative classification of dissolved compounds. Continuing this approach, a semi‐quantitative assessment of the observed rejections in nanofiltration is given in this paper, based on threshold values of key parameters such as molecular weight and molecular weight cut‐off (MWCO), molecular size, pH and pKa, hydrophobicity (logKow) and membrane charge. Experimental values and literature data were used to provide a broad basis for comparison. It was concluded that (a) all categories that contain hydrophobic components are badly defined, in particular for small components, with rejections varying from low to very high, (b) all components that contain hydrophilic components have relatively high rejections and (c) all categories that contain charged components have well‐defined, high rejections (intermediate for membranes with low surface charge). In all cases, the average rejection is higher when the component's molecular weight is larger than the MWCO of the membrane and when the molecular size is larger than the pore size of the membrane. Copyright © 2006 Society of Chemical Industry
Ceftriaxone‐associated biliary pseudolithiasis in children
Authors: Biner Betül , Öner Naci , Çeltik Coşkun , Bostancioğlu Musa , Tunçbilek Nermin , Güzel Ahmet , Karasalihoğlu Serap 
Published: May 2006

AbstractPurpose.Ceftriaxone is known to induce reversible precipitations, known as pseudolithiasis, in the gallbladder and urinary tract. The aim of this study was to investigate the incidence and predisposing factors that contribute to this side effect.Methods.A prospective study was conducted in 156 children admitted for the treatment of various infections with different daily ceftriaxone doses (50 mg/kg, 75 mg/kg, and 100 mg/kg). Sonographic examinations of the gallbladder and urinary tract were performed before treatment on the third and seventh day of therapy, and at the first and second month after the end of treatment. Patients with positive findings were followed with weekly sonographic examinations until the abnormality resolved.Results.Abnormal gallbladder sonograms were demonstrated in 27 children (17%); 16 of them (10%) had gallbladder lithiasis, 11 had gallbladder sludge (7%) (n = 4 on the third day, n = 23 on the seventh day), and 1 developed urolithiasis (0.6%). Five children (19%) were symptomatic. The abnormalities resolved after a mean of 16 days (range 10–30 days). Patients with pseudolithiasis were older and treated with higher drug doses than those with normal sonographic findings (P < 0.01 and P < 0.05, respectively).Conclusions.Biliary pseudolithiasis (and infrequently nephrolithiasis) usually occurs in children receiving high doses of ceftriaxone. It is generally asymptomatic. When this reversible complication becomes symptomatic, unnecessary cholecystectomy should be avoided. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 34:217–222, 2006
Magnetic resonance imaging with T1 dispersion contrast
Authors: Ungersma Sharon E. , Matter Nathaniel I. , Hardy Jonathan W. , Venook Ross D. , Macovski Albert , Conolly Steven M. , Scott Greig C. 
Published: May 2006

AbstractPrepolarized MRI uses pulsed magnetic fields to produce MR images by polarizing the sample at one field strength (∼0.5 T) before imaging at a much lower field (∼50 mT). Contrast reflecting the T1 of the sample at an intermediate field strength is achieved by polarizing the sample and then allowing the magnetization to decay at a chosen “evolution” field before imaging. For tissues whose T1 varies with field strength (T1 dispersion), the difference between two images collected with different evolution fields yields an image with contrast reflecting the slope of the T1 dispersion curve between those fields. Tissues with high protein content, such as muscle, exhibit rapid changes in their T1 dispersion curves at 49 and 65 mT due to cross‐relaxation with nitrogen nuclei in protein backbones. Tissues without protein, such as fat, have fairly constant T1 over this range; subtracting images with two different evolution fields eliminates signal from flat T1 dispersion species. T1 dispersion protein‐content images of the human wrist and foot are presented, showing clear differentiation between muscle and fat. This technique may prove useful for delineating regions of muscle tissue in the extremities of patients with diseases affecting muscle viability, such as diabetic neuropathy, and for visualizing the protein content of tissues in vivo. Magn Reson Med 2006. © 2006 Wiley‐Liss, Inc.
α‐tocopherol affects neuronal plasticity in adult rat dentate gyrus: The possible role of PKCδ
Authors: Ferri Paola , Cecchini Tiziana , Ambrogini Patrizia , Betti Michele , Cuppini Riccardo , Grande Paolo Del , Ciaroni Sandra 
Published: May 2006

AbstractHippocampus dentate gyrus (DG) is characterized by neuronal plasticity processes in adulthood, and polysialylation of NCAM promotes neuronal plasticity. In previous investigations we found that α‐tocopherol increased the PSA‐NCAM‐positive granule cell number in adult rat DG, suggesting that α‐tocopherol may enhance neuronal plasticity. To verify this hypothesis, in the present study, structural remodeling in adult rat DG was investigated under α‐tocopherol supplementation conditions. PSA‐NCAM expression was evaluated by Western blotting, evaluation of PSA‐NCAM‐positive granule cell density, and morphometric analysis of PSA‐NCAM‐positive processes. In addition, the optical density of synaptophysin immunoreactivity and the synaptic profile density, examined by electron microscopy, were evaluated. Moreover, considering that PSA‐NCAM expression has been found to be related to PKCδ activity and α‐tocopherol has been shown to inhibit PKC activity in vitro, Western blotting and immunohistochemistry followed by densitometry were used to analyze PKC. Our results demonstrated that an increase in PSA‐NCAM expression and optical density of DG molecular layer synaptophysin immunoreactivity occurred in α‐tocopherol‐treated rats. Electron microscopy analysis showed that the increase in synaptophysin expression was related to an increase in synaptic profile density. In addition, Western blotting revealed a decrease in phospho‐PKC Pan and phospho‐PKCδ, demonstrating that α‐tocopherol is also able to inhibit PKC activity in vivo. Likewise, immunoreactivity for the active form of PKCδ was lower in α‐tocopherol‐treated rats than in controls, while no changes were found in PKCδ expression. These results demonstrate that α‐tocopherol is an exogenous factor affecting neuronal plasticity in adult rat DG, possibly through PKCδ inhibition. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Development and topography of the lateral olfactory tract in the mouse: Imaging by genetically encoded and injected fluorescent markers
Authors: Walz Andreas , Omura Masayo , Mombaerts Peter 
Published: May 2006

AbstractIn mammals, conventional odorants are detected by OSNs located in the main olfactory epithelium of the nose. These neurons project their axons to glomeruli, which are specialized structures of neuropil in the olfactory bulb. Within glomeruli, axons synapse onto dendrites of projection neurons, the mitral and tufted (M/T) cells. Genetic approaches to visualize axons of OSNs expressing a given odorant receptor have proven very useful in elucidating the organization of these projections to the olfactory bulb. Much less is known about the development and connectivity of the lateral olfactory tract (LOT), which is formed by axons of M/T cells connecting the olfactory bulb to central neural regions. Here, we have extended our genetic approach to mark M/T cells of the main olfactory bulb and their axons in the mouse, by targeted insertion of IRES‐tauGFP in the neurotensin locus. In NT‐GFP mice, we find that M/T cells of the main olfactory bulb mature and project axons as early as embryonic day 11.5. Final innervation of central areas is accomplished before the end of the second postnatal week. M/T cell axons that originate from small defined areas within the main olfactory bulb, as visualized by localized injections of fluorescent tracers in wild‐type mice at postnatal days 1 to 3, follow a dual trajectory: a branch of tightly packed axons along the dorsal aspect of the LOT, and a more diffuse branch along the ventral aspect. The dorsal, but not the ventral, subdivision of the LOT exhibits a topographical segregation of axons coming from the dorsal versus ventral main olfactory bulb. The NT‐GFP mouse strain should prove useful in further studies of development and topography of the LOT, from E11.5 until 2 weeks after birth. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Mechanical behavior of films of miscible polyamide 6/polyamide 6I‐6T blends
Authors: Persyn O. , Miri V. , Lefebvre J.‐M. , Ferreiro V. , Brink T. , Stroeks A. 
Published: May 2006

AbstractThe deformation behavior of miscible PA6/aPA blends films under uniaxial and biaxial tensile drawing has been investigated in relation to blend composition. Whatever be the composition, the initial crystalline structure is ill‐ordered and no evidence of spherulitic morphology was shown. At temperatures beyond the activation of the viscoelastic α relaxation, a ductility improvement upon addition of aPA has been revealed in both uniaxial and biaxial stretching. The decrease in the yield stress with increasing aPA content mainly originates from the reduction in crystal fraction. Regarding the observed evolution in ultimate drawability and strain hardening upon addition of aPA, the latter component of the blend is considered to act as a diluent of the macromolecular network, and the experimental data are fairly well accounted for according to Graessley's theory. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1690–1701, 2006
Bulk and surface spin excitations in thin films of manganites
Authors: Aleshkevych P. , Baran M. , Dyakonov V. , Szymczak R. , Szymczak H. , Baberschke K. , Lindner J. , Lenz K. 
Published: May 2006

AbstractA review of experimental studies of magnon excitations in manganites is presented. A microwave resonance technique, in particular a spin‐wave resonance (SWR) technique, is shown to allow the study of not only bulk properties but also surface properties of manganite films. There are two main theoretical approaches used to interpret the SWR spectra: the volume inhomogeneity and the surface inhomogeneity models. The latter, introduced by Puszkarski, allows the interpretation of the observed surface magnon excitations in thin films. It is found that SWR spectra show evidence of manganites, besides bulk spin‐wave modes, and also of surface spin‐waves. This observation is used to determine the surface magnetic anisotropy. The effect of surface anisotropy on the spin‐wave excitation conditions in epitaxial La0.7Mn1.3O3–δ films is investigated in detail. SWR data give indirect evidence of periodic charge‐ordered stripe forma‐tion. A strong effect of thermal annealing on stripe structure is observed and discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen Bonds as Essential Elements in the Crystal Structures of Three Piperidinium Thiotungstates
Authors: Siemeling Ulrich , Bretthauer Frauke , Bruhn Clemens 
Published: May 2006

AbstractThe crystal structures of [pipH]2[WS4] (1) and the new compounds [pipH]3[WS4](HS) (2) and [pipH]4[WS4][WOS3] (3) (pip = piperidine) were determined. Hydrogen bonds between the piperidinium cations and the thiotungstate anions play a dominant structural role. Their strength and number correlates with the degree of distortion found for the tetrahedral anions. Unshared hydrogen bonds have a considerably stronger effect than bifurcated ones; the effect of trifurcated hydrogen bonds is extremely weak. HS− and [WOS3]2− are considerably stronger H bond acceptors than the [WS4]2− anion.
Synthesen und Strukturen von Übergangsmetall‐Komplexen mit Dithiophosphinato‐ und Trithiophosphonato‐Liganden
Authors: Shafaei‐Fallah Maryam , Shi Weifeng , Fenske Dieter , Rothenberger Alexander 
Published: May 2006

AbstractSyntheses and Structures of Transition Metal Complexes with Dithiophosphinato and Trithiophosphinato LigandsThe reactions of MnCl2 with Ph2P(S)(SSiMe3) produced [Mn(S2PPh2)2(thf)2] (1) and [Mn(S2PPh2)2(dme)] (2) (DME = 1,2‐Dimethoxyethane). The compounds [Co6(S3PPh)2(μ4‐S)2(μ3‐S)2(PPh3)4] (3), [Co2(S3PPh)2(PPh3)2] (4), [Ni(S2PPh)(PPhEt2)2] (5), [Ni(S3PPh)(PPhEt2)2] (6) and [Cu4(S3PPh)2(dppp)2] (8) [dppp = 1,3‐Bis(diphenylphosphanyl)propane] were obtained from reactions of first‐row transition metal halides with PhP(S)(SSiMe3)2 in the presence of tertiary phosphines. In a reaction of PhP(S)(SSiMe3)2 with PhPEt2 PhPEt2PS2Ph (7) was isolated. All compounds were characterized by X‐ray crystallography.
Communication Between Functional and Denervated Muscles Using Radiofrequency
Authors: Jacob Doreen K. , Stefko Susan Tonya , Hackworth Steven A. , Lovell Michael R. , Mickle Marlin H. 
Published: May 2006

OBJECTIVEThis article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis.STUDY DESIGN AND SETTINGTwo sets of experiments were conducted using the gastrocnemius leg muscles of Sprague‐Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus.RESULTSVoltages below 2 V at a 10‐millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions.CONCLUSIONIt is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal.SIGNIFICANCEThis demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.
Effects of Topical Application of Methotrexate on Nasal Mucosa in Rats: A Preclinical Assessment Study
Authors: Ercan Ibrahim , Cakir Burak Ömür , Başak Tülay , Özbal Eltaf Ayça , Şahin Atilla , Balci Gürhan , Turgut Suat 
Published: May 2006

OBJECTIVEThe aim of this study is to investigate dose‐dependent effect of the topical application of methotrexate (MTX) in rats on the normal nasal mucosa, liver tissue, liver enzymes, and hemoglobin levels.STUDY DESIGNPreclinical animal study.SETTINGTwenty male adult wistar albino rats were randomly divided into 4 groups (n = 5). A single puff of MTX (2.5 μg) was applied to both nasal cavities 2 times a day. The animals were given MTX 1 day a week in group 1, 3 days a week in group 2, and 5 days a week in group 3. Control group animals were given 1 puff of physiologic saline to both nasal cavities 5 days a week and 2 times a day. After 28 days, liver biopsies, blood samples, and 5 nasal mucosal biopsies were taken. Histological examination was made with respect to certain parameters semiquantitatively (grade 0‐3). The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and hemoglobin counts were studied from blood samples.RESULTSThere are no statistically significant differences with respect to histopathological parameters between the control group and the groups 1‐3 (P > 0.05). Histopathological examination of liver tissue did not reveal any evident difference between the control and study groups. Mean AST and ALT as liver function tests and hemoglobin counts were within normal limits. Topical application of MTX at these doses has no toxic effect on the nasal mucosa, the liver tissue, AST and ALT levels, and hemoglobin level.CONCLUSIONSThese results have been encouraging to investigate use of the topical application of MTX in nasal manifestation of autoimmune disease or addition of the topical application of MTX to the steroid treatment in cases with massive nasal polyposis resistant to steroids and prone to recurrence.