bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pigmented and nonpigmented ocelli in the brain vesicle of the ascidian larva
Authors: Horie Takeo , Sakurai Daisuke , Ohtsuki Hisashi , Terakita Akihisa , Shichida Yoshinori , Usukura Jiro , Kusakabe Takehiro , Tsuda Motoyuki 
Published: April 2008

AbstractThe vertebrate‐type opsin, Ci‐opsin1, is localized in the outer segments of the photoreceptor cells of larvae of the ascidian Ciona intestinalis. The absorption spectrum of the photopigment reconstituted from Ci‐opsin1 and 11‐cis‐retinal suggested that the photopigment is responsible for photic behavior of the larvae. The structure and function of Ci‐opsin1‐positive photoreceptor cells were examined by immunohistochemistry, confocal microscopy, electron microscopy, laser ablation, and behavioral analysis. Ciona larvae have three morphologically distinct groups of photoreceptor cells in the brain vesicle. Group I and group II photoreceptor cells are associated with the ocellus pigment cell on the right side of the brain vesicle. The outer segments of the group I photoreceptor cells are regularly arranged inside the small cavity encircled by the cup‐shaped pigment cell. The outer segments of the group II photoreceptor cells are located outside the pigment cavity and exposed to the lumen of the brain vesicle. The outer segments of the group III photoreceptor cells are located near the otolith on the left ventral side of the brain vesicle. Thus, the brain vesicle of the ascidian larva has two ocelli: a ‘conventional’ pigmented ocellus containing the group I and group II photoreceptor cells and a novel nonpigmented ocellus solely consisting of the group III photoreceptor cells. Laser ablation experiments suggest that the pigmented ocellus is responsible for the photic swimming behavior. The nonpigmented ocellus might relate to later developmental or physiological events, such as metamorphosis, because Ci‐opsin1 immunoreactivity appears in the late larval stage and becomes intense just before the onset of metamorphosis. J. Comp. Neurol. 509:88–102, 2008. © 2008 Wiley‐Liss, Inc.
Thermodynamic Aspects of Diamond/β‐SiC Composite Films
Authors: Srikanth Vadali V. S. S. , Trindade Vicente Braz , Staedler Thorsten , Jiang Xin 
Published: April 2008

AbstractA thermodynamic equilibrium analysis involving H2CH4Si(CH3)4 (tetramethylsilane, TMS) gas mixtures is made to understand the evolution of major gas‐phase species and to predict the solid‐phase co‐deposition of diamond and β‐SiC phases. The equilibrium compositions are analyzed at the practical deposition conditions of nanocrystalline diamond/β‐SiC composite films. The influence of various predominant species on the equilibrium compositions is investigated.
Vanadium(I) Chloride and Lithium Vanadium(I) Dihydride as Epimetallating Reagents for Unsaturated Organic Substrates: Constitution and Mode of Reaction
Authors: Eisch John J. , Fregene Paul O. , Doetschman David C. 
Published: April 2008

AbstractSubvalent vanadium(I) salts, of empirical formulas, VCl, vanadium(I) chloride and LiVH2, lithium vanadium(I) dihydride, can be conveniently prepared in THF solution, starting at –78 °C, by treating either VCl3 or VCl4 with an appropriate number of equivalents of nBuLi. As judged by the stability of solutions or solid samples of LiVH2, the preparation of LiVH2 from VCl4 is the preferred method. Individual physical characterization of solid samples of VCl or of LiVH2, admixed with their LiCl by‐product, was carried out after removal of all volatiles in vacuo and by the following measurements: 1) gasometric protolysis with glacial acetic acid and measurement of the H2 evolved in the oxidation of VI to VII; 2) infrared spectroscopic search for V–H bands; and 3) examination for unpaired electrons by EPR activity. Such measurements applied to VCl lend strong support for a VI oxidation state but only probable evidence for paramagnetism and for the association of VCl units. Similar measurements applied to LiVH2 give unambiguous gasometric and IR evidence favoring the LiVH2 stoichiometry and the biradical nature of the VH2 anion with a linear array of H–V–H atoms. Chemical characterization of both VCl and LiVH2 toward individual organic substrates, such as olefins, ketones, epoxides and organic halides, yielded convincing evidence that organic radical mechanisms are involved, both for the proven biradical, LiVH2, as well as for the diamagnetic VCl. Finally, the question of why LiVH2 prepared from VCl4 is more stable than the LiVH2 obtained from VCl3 is addressed in terms of the actual coordination sphere of the VH2 anion in THF solution and in the solid state. Preliminary studies comparing the reactivities of LiVH2 and LiCrH2 toward organic substrates indicate that LiVH2 is the distinctly more moderate and usefully selective reductant. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
2‐Azido‐2‐deoxycellulose: Synthesis and 1,3‐Dipolar Cycloaddition
Authors: Zhang Fuyi , Bernet Bruno , Bonnet Véronique , Dangles Olivier , Sarabia Francisco , Vasella Andrea 
Published: April 2008

AbstractChitosan (1) was prepared by basic hydrolysis of chitin of an average molecular weight of 70000 Da, 1H‐NMR spectra indicating almost complete deacetylation. N‐Phthaloylation of 1 yielded the known N‐phthaloylchitosan (2), which was tritylated to provide 3a and methoxytritylated to 3b. Dephthaloylation of 3a with NH2NH2⋅H2O gave the 6‐O‐tritylated chitosan 4a. Similarly, 3b gave the 6‐O‐methoxytritylated 4b. CuSO4‐Catalyzed diazo transfer to 4a yielded 95% of the azide 5a, and uncatalyzed diazo transfer to 4b gave 82% of azide 5b. Further treatment of 5a with CuSO4 produced 2‐azido‐2‐deoxycellulose (7). Demethoxytritylation of 5b in HCOOH gave 2‐azido‐2‐deoxy‐3,6‐di‐O‐formylcellulose (6), which was deformylated to 7. The 1,3‐dipolar cycloaddition of 7 to a range of phenyl‐, (phenyl)alkyl‐, and alkyl‐monosubstituted alkynes in DMSO in the presence of CuI gave the 1,2,3‐triazoles 8–15 in high yields.
Impact of ecologically relevant heat shocks on Hsp developmental function in the vetigastropod Haliotis asinina
Authors: Gunter Helen M. , Degnan Bernard M. 
Published: April 2008

AbstractHeat shock proteins (Hsps) are essential for cellular maintenance, normal differentiation and morphogenesis, and protection against a range of environmental stresses. It is unknown which of these roles takes precedence when they are required simultaneously. Here we examined the impact of thermal stress on the complex developmental expression patterns of HasHsp70 and HasHsp90A in the vetigastropod Haliotis asinina. We find that near‐lethal heat shocks do not alter the spatial demarcation of Hsp expression despite such treatments impacting on the external character of the embryos. Using a suite of molecular markers that are both coexpressed with the Hsps (i.e. in ventrolateral ectoderm and prototroch) and expressed in tissues that have lower (basal) Hsp expression (e.g. serotonergic nervous system and shell gland), we determined that Hsp‐expressing tissues do not incur markedly less thermal damage than adjacent tissues. To explore the relationship of Hsp expression with sensitivity of specific cell territories to heat shock, we focused on the formation of the prototroch, a tissue where HasHsp70 and HasHsp90A are coexpressed. By heat shocking at specific developmental stages, we determined that the most sensitive period of prototroch development is during its early specification and differentiation, which overlaps with the time the Hsps are expressed at their highest levels in these cells. This correlation is consistent with heat shock impairing the function of Hsps in regions of the H. asinina embryo undergoing morphogenesis. J. Exp. Zool. (Mol. Dev. Evol.) 310B:450–464, 2008. © 2008 Wiley‐Liss, Inc.
Independent component analysis of dynamic contrast‐enhanced magnetic resonance images of breast carcinoma: A feasibility study
Authors: Koh Tong San , Thng Choon Hua , Ho Juliana T.S. , Tan Puay Hoon , Rumpel Helmut , Khoo James B.K. 
Published: April 2008

AbstractPurposeTo study the possibility of using independent component analysis (ICA) to identify breast lesions as separate hemodynamic sources on dynamic contrast‐enhanced (DCE) MR images, as depicted by the passage of contrast medium.Materials and MethodsSix patients who were histopathologically confirmed with breast carcinoma underwent DCE MRI with 5 precontrast and 60 postcontrast scans at a time‐resolution of 8 s. A spatial ICA algorithm was applied on the DCE MRI data set to extract spatial component maps corresponding to source locations with different signal time–intensity patterns. To verify the present hypothesis of the ability of ICA to reveal tumor voxels as a separate hemodynamic phase, tumor margins were outlined by an experienced radiologist who was blinded from the ICA results, and the manual outlines were compared with the ICA maps.ResultsConsistently for each of the six patient study cases, it was found that ICA yields a tumor component map associated with typical tumor enhancement patterns of rapid enhancement with washout or plateau. Tumor outlines manually drawn by the radiologist were in good agreement with the tumor locations depicted in the tumor component maps.ConclusionICA may provide an objective method for identifying the outlines of enhancing breast tumors on DCE MR images and to automatically extract the tumor signal intensity–time curve for subsequent tracer kinetics analysis. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Characterization of the pH‐dependent dissociation of a multimeric metalloprotein Streptomyces rubiginosus xylose isomerase by ESI FT‐ICR mass spectrometry
Authors: Jänis Janne , Pasanen Salla , Rouvinen Juha , Vainiotalo Pirjo 
Published: April 2008

AbstractWe report an analysis of the pH‐dependent dissociation of a multimeric metalloprotein, xylose isomerase from Streptomyces rubiginosus (XI), by electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometry. Xylose isomerases are industrially significant enzymes that catalyze interconversion of aldose and ketose sugars. XI is biologically active as a ∼173‐kDa tetrameric complex, comprised of four identical ∼43‐kDa subunits and eight metal cations, unequivocally identified as the Mg2+ cations in this work. ESI FT‐ICR mass spectra of XI measured in the pH range of 3.0–6.9 indicated that the dissociation of the intact holo‐tetramer is initiated by the loss of all eight Mg2+ cations at pH ≤5.0, followed by step‐by‐step dissociation of the remaining apo‐tetramer to trimers, dimers and monomers. In addition, a ∼346‐kDa protein octamer was detected at pH 6.9. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of a new matrix‐free laser desorption/ionization method through statistic studies: comparison of the DIAMS (desorption/ionization on self‐assembled monolayer surface) method with the MALDI and TGFA‐LDI techniques
Authors: Bounichou Matthieu , Sanguinet Lionel , Elouarzaki Kamal , Alévêque Olivier , Dias Marylène , Levillain Eric , Rondeau David 
Published: April 2008

AbstractThis work demonstrates that the desorption/ionization on self‐assembled monolayer surface (DIAMS) mass spectrometry, a recent matrix‐free laser desorption/ionization (LDI) method based on an organic target plate, is as statistically repeatable and reproducible as matrix assisted laser desorption ionization (MALDI) and thin gold film‐assisted laser desorption/ionization (TGFA‐LDI) mass spectrometries. On lipophilic DIAMS of target plates with a mixture of glycerides, repeatability/reproducibility has been estimated at 15 and 30% and the relative detection limit has been evaluated at 0.3 and 3 pmol, with and without NaI respectively. Salicylic acid and its d6‐isomer analysis confirm the applicability of the DIAMS method in the detection of compounds of low molecular weight. Copyright © 2008 John Wiley & Sons, Ltd.
Color stability of frozen whole tilapia exposed to pre‐mortem treatment with carbon monoxide
Authors: Mantilla David , Kristinsson Hordur G , Balaban Murat O , Otwell W Steven , Chapman Frank A , Raghavan Sivakumar 
Published: April 2008

AbstractBACKGROUND: Color of muscle foods plays a major role in consumer perception of meat quality. Carbon monoxide (CO) has been successfully used for improving color of packaged meat and fish products. In this study, we wanted to investigate pre‐mortem treatment of live tilapia using 100% CO for its ability to improve the color of frozen whole tilapia. We compared untreated and CO‐treated whole, gutted tilapia, frozen for 2 and 4 months at − 20 °C. Frozen tilapia samples were thawed overnight at 4 °C, filleted and analyzed for their color, heme peak wavelength and CO concentration.RESULTS: Euthanasia using CO significantly increased redness (a* value) and lightness (L* value) of tilapia white and red muscle. Frozen storage significantly (P < 0.05) decreased redness of both CO‐treated and untreated tilapia. However, even after 4 months of frozen storage, a*‐value of CO‐treated tilapia was similar to fresh untreated tilapia fillets. Heme peak wavelengths of CO‐euthanized tilapia were higher than in untreated tilapia and there was no significant (P > 0.05) decrease in heme peak wavelengths of CO‐treated tilapia white and red muscle during frozen storage. The CO content of frozen euthanized tilapia fillets was significantly (P > 0.05) higher than in untreated fillets. In general, red muscle tissue of euthanized tilapia had a higher concentration of CO than white muscle.CONCLUSION: Color stability of tilapia fillets was significantly improved by pre‐mortem CO treatment. The color of CO‐treated fillets was retained during frozen storage compared to untreated fillets. Hence, pre‐mortem CO treatment could be used as a new method for improving color of tilapia. Copyright © 2008 Society of Chemical Industry
High‐performance liquid chromatography procedure for the determination of flavor enhancers in consumer chocolate products and artificial flavors
Authors: Risner Charles H , Kiser Melissa J 
Published: April 2008

AbstractBACKGROUND: A number of individual high‐performance liquid chromatography (HPLC) procedures exist for the analysis of maltol, theobromine, ethyl maltol, catechin, vanillic acid, caffeine, vanillin, epicatechin, and ethyl vanillin. A single procedure utilizing simple sample preparation and less sophisticated equipment would be advantageous for the analysis of different sample types containing these compounds.RESULTS: An HPLC procedure has been developed using water as the extract for consumer products and artificial flavors. A methanol–water gradient was used to elute the compounds of interest using a reverse‐phase column. Absorbance detection using a wavelength of 273 nm was used to monitor the eluent. Recoveries for these compounds ranged from 88% to 104%.CONCLUSIONS: Results obtained for theobromine, catechin, caffeine, and epicatechin in Standard Reference Material 2380 Baking Chocolate compare well with those found in its certificate of analysis verifying that the procedure is valid. Vanillic acid and ethyl vanillic acid were found as oxidation products of vanillin and ethyl vanillin in both standards and some consumer products. Copyright © 2008 Society of Chemical Industry
Protective effect of polyphenol‐rich extract prepared from Malaysian cocoa (Theobroma cacao) on glucose levels and lipid profiles in streptozotocin‐induced diabetic rats
Authors: Ruzaidi Azli Mohd Mokhtar , Abbe Maleyki Mhd Jalil , Amin Ismail , Nawalyah Abdul Ghani , Muhajir Hamid 
Published: April 2008

AbstractBACKGROUND: Cocoa beans are used for preparing cocoa liquor and cocoa powder, which are the main ingredients of cocoa‐based products. Previous studies have reported the health benefits of cocoa polyphenols in reducing the risk of cardiovascular diseases. However, there is no report on the efficacy of cocoa polyphenols on diabetes mellitus. Therefore this study was designed to evaluate the protective effect of cocoa polyphenol‐rich extract (CE) on glucose levels and lipid profiles in streptozotocin (STZ)‐induced diabetic rats. Male Sprague‐Dawley rats were divided into diabetic control, diabetic CE and diabetic glibenclamide groups.RESULTS: Three different dosages of CE (10, 20 and 30 mg per 100 g body weight) were administered orally once a day for 1 week before STZ injection and for 3 weeks thereafter. The results showed that CE could normalise the body weight loss caused by STZ. In the 20 mg CE‐pretreated group there was a 143% increase in plasma glucose levels, compared with a 226% increase in diabetic control rats. CE could also normalise total cholesterol, triglycerides and high‐density lipoprotein cholesterol at the end of the experiment compared with the baseline.CONCLUSION: The present study suggests that pretreatment with CE from roasted cocoa beans could prevent the development of diabetes induced by STZ injection in rats. Copyright © 2008 Society of Chemical Industry
Proteomics in gram‐negative bacterial outer membrane vesicles
Authors: Lee Eun‐Young , Choi Dong‐Sic , Kim Kwang‐Pyo , Gho Yong Song 
Published: April 2008

AbstractGram‐negative bacteria constitutively secrete outer membrane vesicles (OMVs) into the extracellular milieu. Recent research in this area has revealed that OMVs may act as intercellular communicasomes in polyspecies communities by enhancing bacterial survival and pathogenesis in hosts. However, the mechanisms of vesicle formation and the pathophysiological roles of OMVs have not been clearly defined. While it is obvious that mass spectrometry‐based proteomics offers great opportunities for improving our knowledge of bacterial OMVs, limited proteomic data are available for OMVs. The present review aims to give an overview of the previous biochemical, biological, and proteomic studies in the emerging field of bacterial OMVs, and to give future directions for high‐throughput and comparative proteomic studies of OMVs that originate from diverse Gram‐negative bacteria under various environmental conditions. This article will hopefully stimulate further efforts to construct a comprehensive proteome database of bacterial OMVs that will help us not only to elucidate the biogenesis and functions of OMVs but also to develop diagnostic tools, vaccines, and antibiotics effective against pathogenic bacteria. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 535–555, 2008
Generalized MRI reconstruction including elastic physiological motion and coil sensitivity encoding
Authors: Odille Freddy , Cîndea Nicolae , Mandry Damien , Pasquier Cédric , Vuissoz Pierre‐André , Felblinger Jacques 
Published: April 2008

AbstractThis article describes a general framework for multiple coil MRI reconstruction in the presence of elastic physiological motion. On the assumption that motion is known or can be predicted, it is shown that the reconstruction problem is equivalent to solving an integral equation—known in the literature as a Fredholm equation of the first kind—with a generalized kernel comprising Fourier and coil sensitivity encoding, modified by physiological motion information. Numerical solutions are found using an iterative linear system solver. The different steps in the numerical resolution are discussed, in particular it is shown how over‐determination can be used to improve the conditioning of the generalized encoding operator. Practical implementation requires prior knowledge of displacement fields, so a model of patient motion is described which allows elastic displacements to be predicted from various input signals (e.g., respiratory belts, ECG, navigator echoes), after a free‐breathing calibration scan. Practical implementation was demonstrated with a moving phantom setup and in two free‐breathing healthy subjects, with images from the thoracic‐abdominal region. Results show that the method effectively suppresses the motion blurring/ghosting artifacts, and that scan repetitions can be used as a source of over‐determination to improve the reconstruction. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Interleukin‐1 exacerbates focal cerebral ischemia and reduces ischemic brain temperature in the rat
Authors: Parry‐Jones Adrian R. , Liimatainen Timo , Kauppinen Risto A. , Gröhn Olli H.J. , Rothwell Nancy J. 
Published: April 2008

AbstractThe proinflammatory cytokine interleukin‐1 (IL‐1) is a key mediator of inflammation in cerebral ischemia, but its precise mechanisms of action remain elusive. Temperature is critical to outcome in brain injury and given the importance of IL‐1 in pyrogenesis this has clear mechanistic implications. IL‐1 exacerbates ischemia independently of core (rectal) temperature. However, it is temperature in the ischemic brain that influences outcome and rectal temperature is likely to be a poor surrogate marker. This study tested the hypothesis that IL‐1 exacerbates cerebral ischemia by increasing ischemic brain temperature. Wistar rats undergoing transient middle cerebral artery occlusion received either 4 μg/kg IL‐1 (n = 9) or vehicle (n = 10) intraperitoneally. NMR‐generated maps of brain temperature, tissue perfusion, and the trace of the diffusion tensor were collected during occlusion, early reperfusion, and at 24 hr. IL‐1 significantly increased ischemic damage at 24 hr by 35% but rectal temperature did not vary significantly between groups. However, ischemic brain was 1.7°C cooler on reperfusion in IL‐1‐treated animals (vs. vehicle) and a corresponding reduction in cerebral blood flow was identified in the ischemic striatum. Contrary to the stated hypothesis, IL‐1 reduced ischemic brain temperature during reperfusion and this may be due to a reduction in tissue perfusion. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Quantitative magnetic resonance spectroscopy in the entire human cervical spinal cord and beyond at 3T
Authors: Henning Anke , Schär Michael , Kollias Spyros S. , Boesiger Peter , Dydak Ulrike 
Published: April 2008

AbstractQuantitative magnetic resonance spectroscopy (MRS) amends differential diagnostics of neurological pathology. However, due to technical challenges, it has rarely been applied to the spinal cord and has mainly been restricted to the very upper part of the cervical spine. In this work, an improved acquisition protocol is proposed that takes technical problems as strong magnetic field inhomogeneities, pulsatile flow of the cerebrospinal fluid (CSF), and small voxel size into account. For that purpose, inner‐volume saturated point‐resolved spectroscopy sequence (PRESS) localization, ECG triggering, and localized higher‐order shimming and F0 determination, based on high‐resolution cardiac‐triggered static magnetic field B0 mapping, are combined. For inner‐volume saturation a highly selective T1‐ and B1‐insensitive outer‐volume suppression (OVS) sequence based on broadband RF pulses with polynomial‐phase response (PPR) is used. Validation is performed in healthy volunteers and patients with multiple sclerosis and intramedullary tumors. The applicability of spinal cord MRS is extended to the entire cervical spine. Spectral quality and its consistency are improved. In addition, high quality MRS patient data from a lesion that occluded the spinal canal in the thoracic spinal cord could be acquired. A quantitative analysis of patient spectra and spectra from healthy volunteers at different positions along the spinal cord underlines the diagnostic value of spinal cord MRS. Magn Reson Med 59:1250–1258, 2008. © 2008 Wiley‐Liss, Inc.