bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structure, and Photochemistry of an Organic Heptamolybdate‐Monomolybdate
Authors: Wutkowski Adam , Srinivasan Bikshandarkoil R. , Naik Ashish R. , Schütt Christian , Näther Christian , Bensch Wolfgang 
Published: April 2011

AbstractTreatment of MoO3 with butan‐1‐amine (BuNH2) or pyrrolidine (PyrNH2) results in the formation of (BuNH3)8[(Mo7O24)(MoO4)]·3H2O (1; BuNH3 = butan‐1‐aminium) or (PyrNH2)6[(Mo7O24]·2H2O (2; PyrNH2 = pyrrolidinium), respectively. On irradiation with sunlight, compound 1, which is an organic heptamolybdate [Mo7O24]6– that contains a cocrystallized monomolybdate [MoO4]2– in the same compound, is transformed to an oxido‐bridged diheptamolybdate (BuNH3)10[(Mo7O22)(μ2‐O)2(Mo7O22)]·5.5H2O (1b). The [Mo7O24]6– units in 1 and 2 are made up of edge‐sharing [MoO6] octahedra, whereas the central unit in 1b is a bis(μ2‐O)‐bridged heptamolybdate dimer. Hydrogen bonding among the lattice water molecules in 1 results in the formation of a water octamer, whereas hydrogen bonding between the lattice water molecules and [Mo7O24]6– in 2 results in the formation of a one‐dimensional water‐linked heptamolybdate chain. Supramolecular structures, photochemistry, and thermal properties of 1, 1b, and 2 are reported. For comparison of photochemical behavior, two more polyoxomolybdates, (PrNH3)6[Mo7O24]·3H2O (3; PrNH3 = propan‐1‐aminium) and (PentNH3)6[Mo7O24]·3H2O (4; PentNH3 = pentan‐1‐aminium), were prepared and characterized.
Synthesis and Characterization of Homoleptic and Heteroleptic Cobalt, Nickel, Copper, Zinc and Cadmium Compounds with the 2‐(Tosylamino)‐N‐[2‐(tosylamino)benzylidene]aniline Ligand
Authors: Sousa‐Pedrares Antonio , Viqueira Joaquin A. , Antelo Jorge , Labisbal Elena , Romero Jaime , Sousa Antonio , Nascimento Otaciro R. , García‐Vázquez José A. 
Published: April 2011

AbstractThe electrochemical oxidation of anodic metal (cobalt, nickel, copper, zinc and cadmium) in an acetonitrile solution of the Schiff‐base ligand 2‐(tosylamino)‐N‐[2‐(tosylamino)benzylidene]aniline (H2L) afforded the homoleptic compounds [ML]. The addition of 1,1‐diphenylphosphanylmethane (dppm), 2,2′‐bipyridine (bipy) or 1,10‐phenanthroline (phen) to the electrolytic phase gave the heteroleptic complexes [NiL(dppm)], [ML(bipy)] and [ML(phen)]. The crystal structures of H2L (1), [NiL] (2), [CuL] (3), [NiL(dppm)] (4), [CoL(phen)] (5), [CuL(bipy)] (6) and [Zn(Lphen)] (7) were determined by X‐ray diffraction. The homoleptic compounds [NiL] and [CuL] are mononuclear with a distorted square planar [MN3O] geometry with the Schiff base acting as a dianionic (NamideNamideNimineOtosyl) tetradentate ligand. Both compounds exhibit an unusual π–π stacking interaction between a six‐membered chelate ring containing the metal and a phenylic ring of the ligand. In the heteroleptic complex [NiL(dppm)], the nickel atom is in a distorted tetrahedral [NiN3P] environment defined by the imine, two amide nitrogen atoms of the L2– dianionic tridentate ligand and one of the phosphorus atoms of the dppm molecule. In the other heteroleptic complexes, [CoL(phen)], [CuL(bipy)] and [ZnL(phen)], the metal atom is in a five‐coordinate environment defined by the imine, two amide nitrogen atoms of the dianionic tridentate ligand and the two bipyridine or phenanthroline nitrogen atoms. The compounds were characterized by microanalysis, IR and UV/Vis (Co, Ni and Cu complexes) spectroscopy, FAB mass spectrometry and 1H NMR ([NiL] and Zn and Cd complexes) and EPR spectroscopy (Cu complexes).
Antioxidant and aldose reductase inhibition activity of Ligustrum japonicum and Olea europaea L. leaf extracts
Authors: Papoti Vassiliki T. , Pegklidou Kyriaki , Perifantsi Eleftheria , Nenadis Nikolaos , Demopoulos Vassilios J. , Tsimidou Maria Z. 
Published: April 2011

AbstractLigustrum japonicum and Olea europaea leaf extracts prepared via domestic techniques were studied for antioxidant and aldose reductase inhibitory activity (ARI) in relation to individual phenol/flavonoid composition (HPLC‐various detection means) and content. On the same extract weight basis L. japonicum leaf extracts, poorer in total polar phenol (TPP) content and in most cases in flavonoids, were less efficient than olive leaf extracts in radical scavenging and in retarding lipid oxidation. On the same TPP content basis, the former were of comparable efficiency in radical scavenging but exhibited lower activity than the latter in bulk oils or liposomes. L. japonicum extracts were characterized by the presence of verbascoside and apigenin derivatives, whereas O. europaea extracts by that of oleuropein. Superiority of L. japonicum infusion versus O. europaea infusion was evidenced using the ARI activity assay either on the same extract weight or on TPP content basis. The former was also superior in comparison to oleuropein, tyrosol, and hydroxytyrosol activity. These findings suggest the presence of other active compounds besides the so far identified phenolics and enhance our view on the importance of Oleaceae plants as sources of bioactive compounds beyond O. europaea.Practical applications: Oleaceae plants are a unique source for the secoiridoid oleuropein or verbascoside that confer well documented biological properties. On continuation of our effort to valorize plants of this family as sources for functional constituents we examined, in parallel, leaf extracts of the less investigated species Ligustrum japonicum versus those of Olea europaea L. The data presented for the extracts obtained via domestic preparations techniques (infusions, decoctions, tinctures) are expected to attract the interest of those involved in herbal teas and dietary supplements sector.
Efficient Room‐Temperature One‐Pot Synthesis of 2‐Amino‐3‐alkyl(3‐aryl)quinazolin‐4(3H)‐ones
Authors: Lecoutey Cédric , Fossey Christine , Rault Sylvain , Fabis Frédéric 
Published: April 2011

AbstractStarting from anthranilates, the one‐pot successive addition of ethoxycarbonylisothiocyanate, alkyl‐ or arylamines, and the coupling reagent EDCI led to the clean, room‐temperature formation of carbamate‐protected 2‐amino‐3‐alkyl(3‐aryl)quinazolin‐4(3H)‐ones in up to 93 % yield. This method provides a practical alternative to previously reported procedures for the synthesis of 2‐amino‐3‐substituted quinazolin‐4(3H)‐ones.
Dynamic response and optimal design of structures with large mass ratio TMD
Authors: De Angelis Maurizio , Perno Salvatore , Reggio Anna 
Published: April 2011

AbstractThis paper investigates the dynamic behavior and the seismic effectiveness of a non‐conventional Tuned Mass Damper (TMD) with large mass ratio. Compared with conventional TMD, the device mass is increased up to be comparable with the mass of the structure to be protected, aiming at a better control performance. In order to avoid the introduction of an excessive additional weight, masses already present on the structure are converted into tuned masses, retaining structural or architectural functions beyond the mere control function. A reduced order model is introduced for design purposes and the optimal design of a large mass ratio TMD for seismic applications is then formulated. The design method is specifically developed to implement High‐Damping Rubber Bearings (HDRB) to connect the device mass to the main structure, taking advantage of combining stiffness and noticeable damping characteristics. Ground acceleration is modeled as a Gaussian random process with white noise power spectral density. A numerical searching technique is used to obtain the optimal design parameter, the frequency ratio alpha, which minimizes the root‐mean‐square displacement response of the main structure. The study finally comprises shaking table tests on a 1:5 scale model under a wide selection of accelerograms, both artificial and natural, to assess the seismic effectiveness of the proposed large mass ratio TMD. Copyright © 2011 John Wiley & Sons, Ltd.
The Influence of Pt Loading, Support and Nafion Content on the Performance of Direct Methanol Fuel Cells: Examined on the Example of the Cathode
Authors: Xue X. , Bock C. , Birry L. , MacDougall B. R. 
Published: April 2011

AbstractNano‐sized Pt colloids were prepared using the polyol method and supported on Ketjen black EC 600J (KB), Vulcan XC‐72 (VC) and high surface area graphite 300 (HG). The effects of the Nafion ionomer content, and the Pt loading of the cathode catalyst layer as well as the Pt loading on the support on the performance of direct methanol fuel cells (DMFCs), were studied. The membrane electrode assemblies (MEAs) were analysed using current–voltage curves, cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and adsorbed CO stripping voltammetry. Optimum Nafion to carbon (N/C) ratios (N/C being defined as the weight ratio of the Nafion ionomer to the carbon) were determined. The optimum N/C ratios were found to depend on the support as follows, 1.4, 0.7 and 0.5 for Pt/KB, Pt/VC and Pt/HG, respectively and to be independent of the Pt/C loading range of 20–80 wt% tested in this work. The highest DMFC performances, as well as the highest electrochemical active surface areas, and improved gas diffusivities, were achieved using these ratios. For the catalysts prepared in this work, the average Pt crystallite size was found to decrease with increasing surface area of the support for a particular Pt loading. MEAs made using KB as support and the optimal N/C ratio of 1.4 showed the best performances, i.e. higher than the VC and HG supports for any N/C ratio. The highest DMFC performance was observed using 60 wt% Pt on KB cathode electrodes of 1 mg Pt cm–2loading and an N/C value of 1.4. For all three supports studied, the 60 wt% Pt on carbon loading resulted in the best DMFC performance. This may be linked to the Pt particle size and catalyst preparation method used in this work. In comparison to literature results, high DMFC performances were achieved using relatively ‘low' Pt and Ru loadings. For example, a maximum power density of >100 mW cm–2at 60 °C was observed using a 1 mg Pt cm–2cathode loading and a 2 mg PtRu cm–2anode loading.
p14Arf acts as an antagonist of HMGA2 in senescence of mesenchymal stem cells—implications for benign tumorigenesis
Authors: Markowski Dominique Nadine , Winter Nina , Meyer Frauke , von Ahsen Inga , Wenk Heiner , Nolte Ingo , Bullerdiek Jörn 
Published: April 2011

AbstractHMGA2 is a major regulator of benign tumorigenesis from mesenchyme‐derived tissues and stem‐cell self‐renewal. It has been postulated that HMGA2 mediates its critical function by decreasing p16Ink4a/p14Arf expression and cellular senescence. To repress the oncogenic activity of HMGA2, the lin‐28‐let‐7 axis is thought to increasingly repress the expression of HMGA2 with age. To understand the HMGA2‐p14Arf‐relationship in benign tumorigenesis, we performed a series of experiments on mesenchymal stem‐cells, i.e., the proposed cells of origin of lipomas and uterine leiomyomas. The expression of both genes was inversely correlated during senescence in vitro but contrary to the expectations in adipose tissue derived stem cells (ADSCs) stimulation of HMGA2 by FGF1 increased the expression of p14Arf. Based on the assumption that in ADSCs p14Arf is repressing HMGA2, siRNA silencing of p14Arf was performed resulting in a significant upregulation of HMGA2. To see if p14Arf can repress HMGA2 by a TP53‐dependent mechanism, nutlin‐3, a known MDM2 antagonist, was used which not only increased the activity of the senescence, associated markers p21 and beta‐galactosidase, but also decreased the expression of HMGA2, suggesting that p14Arf indeed influences HMGA2 by a p53‐dependent mechanism because nutlin‐3 stabilizes p53. Accordingly, the HMGA2 response triggered by serum was reduced by treatment of ADSCs with nutlin‐3. As to the interaction between HMGA2 and p14Arf in benign tumorigenesis, we propose a model where akin to MSC self‐renewal during tissue repair the simultaneous increase of p14Arf with HMGA2 ensures genomic stability, whereas in turn p14Arf can repress HMGA2 via TP53. © 2011 Wiley‐Liss, Inc.
Selenoprotein S expression in reactive astrocytes following brain injury
Authors: Fradejas Noelia , Del Carmen Serrano‐PÉREZ Maria , Tranque Pedro , Calvo Soledad 
Published: April 2011

AbstractSelenoprotein S (SelS) is an endoplasmic reticulum (ER)‐resident protein involved in the unfolded protein response. Besides reducing ER‐stress, SelS attenuates inflammation by decreasing pro‐inflammatory cytokines. We have recently shown that SelS is responsive to ischemia in cultured astrocytes. To check the possible association of SelS with astrocyte activation, here we investigate the expression of SelS in two models of brain injury: kainic acid (KA) induced excitotoxicity and cortical mechanical lesion. The regulation of SelS and its functional consequences for neuroinflammation, ER‐stress, and cell survival were further analyzed using cultured astrocytes from mouse and human. According to our immunofluorescence analysis, SelS expression is prominent in neurons and hardly detectable in astrocytes from control mice. However, brain injury intensely upregulates SelS, specifically in reactive astrocytes. SelS induction by KA was evident at 12 h and faded out after reaching maximum levels at 3–4 days. Analysis of mRNA and protein expression in cultured astrocytes showed SelS upregulation by inflammatory stimuli as well as ER‐stress inducers. In turn, siRNA‐mediated SelS silencing combined with adenoviral overexpression assays demonstrated that SelS reduces ER‐stress markers CHOP and spliced XBP‐1, as well as inflammatory cytokines IL‐1β and IL‐6 in stimulated astrocytes. SelS overexpression increased astrocyte resistance to ER‐stress and inflammatory stimuli. Conversely, SelS suppression compromised astrocyte viability. In summary, our results reveal the upregulation of SelS expression in reactive astrocytes, as well as a new protective role for SelS against inflammation and ER‐stress that can be relevant to astrocyte function in the context of inflammatory neuropathologies. © 2011 Wiley‐Liss, Inc.
Targeted downregulation of N‐acetylgalactosamine 4‐sulfate 6‐O‐sulfotransferase significantly mitigates chondroitin sulfate proteoglycan‐mediated inhibition
Authors: Karumbaiah Lohitash , Anand Sanjay , Thazhath Rupal , Zhong Yinghui , Mckeon Robert J. , Bellamkonda Ravi V. 
Published: April 2011

AbstractChondroitin sulfate‐4,6 (CS‐E) glycosaminoglycan (GAG) upregulation in astroglial scars is a major contributor to chondroitin sulfate proteoglycan (CSPG)‐mediated inhibition [Gilbert et al. (2005) Mol Cell Neurosci 29:545–558]. However, the role of N‐acetylgalactosamine 4‐sulfate 6‐O‐sulfotransferase (GalNAc4S6ST) catalyzed sulfation of CS‐E, and its contribution to CSPG‐mediated inhibition of CNS regeneration remains to be fully elucidated. Here, we used in situ hybridization to show localized upregulation of GalNAc4S6ST mRNA after CNS injury. Using in vitro spot assays with immobilized CS‐E, we demonstrate dose‐dependent inhibition of rat embryonic day 18 (E18) cortical neurons. To determine whether selective downregulation of CS‐E affected the overall inhibitory character of extracellular matrix produced by reactive astrocytes, single [against (chondroitin 4) sulfotransferase 11 (C4ST1) or GalNAc4S6ST mRNA] or double [against C4ST1 and GalNAc4S6ST mRNA] siRNA treatments were conducted and assayed using quantitative real‐time polymerase chain reaction and high‐performance liquid chromatography to confirm the specific downregulation of CS‐4S GAG (CS‐A) and CS‐E. Spot and Bonhoeffer stripe assays using astrocyte‐conditioned media from siRNA‐treated rat astrocytes showed a significant decrease in inhibition of neuronal attachment and neurite extensions when compared with untreated and TGFα‐treated astrocytes. These findings reveal that selective attenuation of CS‐E via siRNA targeting of GalNAc4S6ST significantly mitigates CSPG‐mediated inhibition of neurons, potentially offering a novel intervention strategy for CNS injury. © 2011 Wiley‐Liss, Inc.
Are measurements from excised leaves suitable for modeling diurnal patterns of gas exchange of intact leaves?
Authors: Miyazawa Yoshiyuki , Tateishi Makiko , Komatsu Hikaru , Kumagai Tomo'omi , Otsuki Kyoichi 
Published: April 2011

AbstractTo examine the feasibility of using ecophysiological data from excised leaves for a meteorological simulation model of gas exchange, we compared the obtained gas exchange rates and the modelled ones using excised leaves and those using intact leaves. Instantaneous gas exchange rates of excised leaves and stomatal control in response to environmental conditions were not significantly different from those of attached leaves. Modelled gas exchange rates based on excised leaf data showed a good fit to the diurnal patterns of in situ measurements. This suggests that use of excised leaf data to predict gas exchange of intact leaves is permissible as long as the effects of excision are pre‐screened as described in this paper. Copyright © 2011 John Wiley & Sons, Ltd.
Synthetic Studies toward Communesins
Authors: Zuo Zhiwei , Ma Dawei 
Published: April 2011

AbstractCommunesins A–H are a growing family of natural products isolated from a marine fungal strain of Penicillium species. Preliminary biological evaluation has revealed that these compounds possess insecticidal activity and cytotoxicity against several tumor cell lines. Their interesting biological activities and unique structures have attracted considerable attention of synthetic chemists worldwide. To date, several elegant protocols for assembling the core structure of these indole alkaloids have been described, including intermolecular Diels–Alder reaction of methylated aurantioclavine with quinine methide imine and intramolecular hetero Diels–Alder reaction of the azaortho‐xylylene intermediates. Recently, three completed total syntheses for communesin F have been disclosed, in which the crucial vicinal quaternary stereogenic centers were constructed by employing an intramolecular cyclopropanation; an intramolecular Heck reaction of a tetrasubstituted alkene, or an oxidative coupling of a 3‐substituted indole, as the key step. Accompanying the total synthesis, the absolute configuration of natural communesin F was established as 6R,7R,8R,9S,11R. However, total syntheses of other members of communesin family that contain an epoxide moiety have not been achieved, which will stimulate more synthetic studies.
Total Syntheses of Kapakahines E and F
Authors: Rainier Jon D. , Espejo Vinson R. 
Published: April 2011

AbstractThis article describes the synthesis of kapakahines E and F, along with what we believe to be a general method for the total synthesis of the kapakahine family of marine natural products. The method utilizes a unique heterodimerization reaction between bromopyrroloindolines and indole nucleophiles, a novel pyrroloindoline‐to‐α‐carboline rearrangement, and a Negishi coupling reaction of C(3)‐iodoindoles.
Triclosan: environmental exposure, toxicity and mechanisms of action
Authors: Dann Andrea B. , Hontela Alice 
Published: April 2011

ABSTRACTTriclosan [5‐chloro‐2‐(2,4‐dichlorophenoxy)phenol; TCS] is a broad spectrum antibacterial agent used in personal care, veterinary, industrial and household products. TCS is commonly detected in aquatic ecosystems, as it is only partially removed during the wastewater treatment process. Sorption, biodegradation and photolytic degradation mitigate the availability of TCS to aquatic biota; however the by‐products such as methyltriclosan and other chlorinated phenols may be more resistant to degradation and have higher toxicity than the parent compound. The continuous exposure of aquatic organisms to TCS, coupled with its bioaccumulation potential, have led to detectable levels of the antimicrobial in a number of aquatic species. TCS has been also detected in breast milk, urine and plasma, with levels of TCS in the blood correlating with consumer use patterns of the antimicrobial. Mammalian systemic toxicity studies indicate that TCS is neither acutely toxic, mutagenic, carcinogenic, nor a developmental toxicant. Recently, however, concern has been raised over TCS's potential for endocrine disruption, as the antimicrobial has been shown to disrupt thyroid hormone homeostasis and possibly the reproductive axis. Moreover, there is strong evidence that aquatic species such as algae, invertebrates and certain types of fish are much more sensitive to TCS than mammals. TCS is highly toxic to algae and exerts reproductive and developmental effects in some fish. The potential for endocrine disruption and antibiotic cross‐resistance highlights the importance of the judicious use of TCS, whereby the use of TCS should be limited to applications where it has been shown to be effective. Copyright © 2011 John Wiley & Sons, Ltd.
Subchronic inhalation toxicity of iron oxide (magnetite, Fe3O4) in rats: pulmonary toxicity is determined by the particle kinetics typical of poorly soluble particles
Authors: Pauluhn Jürgen 
Published: April 2011

ABSTRACTWistar rats were nose‐only exposed to pigment‐sized iron oxide dust (Fe3O4, magnetite) in a subchronic 13‐week inhalation study according to the OECD testing guidelines TG#413 and GD#39. A 4 week pilot study with a 6 month post exposure period served as basis for validating the kinetic modeling approaches utilized to design the subchronic study. Kinetic analyses made during this post exposure period demonstrated that a diminution in particle clearance and lung inflammation occurred at cumulative exposure levels exceeding the lung overload threshold. Animals were exposed 6 h per day, five days per week for 13 consecutive weeks at actual concentrations of 0, 4.7, 16.6 and 52.1 mg m−3 (mass median aerodynamic diameter ≈1.3 μm, geometric standard deviation = 2). The exposure to iron oxide dust was tolerated without mortality, consistent changes in body weights, food and water consumption or systemic toxicity. While general clinical pathology and urinalysis were unobtrusive, hematology revealed changes of unclear toxicological significance (minimally increased differential neutrophil counts in peripheral blood). Elevations of neutrophils in bronchoalveolar lavage (BAL) appeared to be the most sensitive endpoint of study. Histopathology demonstrated responses to particle deposition in the upper respiratory tract (goblet cell hyper‐ and/or metaplasia, intraepithelial eosinophilic globules in the nasal passages) and the lower respiratory tract (inflammatory changes in the bronchiolo‐alveolar region). Consistent changes suggestive of pulmonary inflammation were evidenced by BAL, histopathology, increased lung and lung‐associated‐lymph node (LALN) weights at 16.6 and 52.1 mg m−3. Increased septal collagenous fibers were observed at 52.1 mg m−3. Particle translocation into LALN occurred at exposure levels causing pulmonary inflammation. In summary, the retention kinetics iron oxide reflected that of poorly soluble particles. The empirical no‐observed‐adverse‐effect level (NOAEL) and the lower bound 95% confidence limit on the benchmark concentration (BMCL) obtained by benchmark analysis was 4.7 and 4.4 mg m−3, respectively, and supports an OEL (time‐adjusted chronic occupational exposure level) of 2 mg m−3 (alveolar fraction). Copyright © 2011 John Wiley & Sons, Ltd.