bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple Reaction Pathways Operating in the Mechanism of Vinylogous Mannich‐Type Reaction Activated by a Water Molecule
Authors: Uematsu Ryohei , Maeda Satoshi , Taketsugu Tetsuya 
Published: October 2013

AbstractA systematic search for reaction pathways for the vinylogous Mannich‐type reaction was performed by the artificial force induced reaction method. This reaction affords δ‐amino‐γ‐butenolide in one pot by mixing 2‐trimethylsiloxyfuran, imine, and water under solvent‐free conditions. Surprisingly, the search identified as many as five working pathways. Among them, two concertedly produce anti and syn isomers of the product. Another two give an intermediate, which is a regioisomer of the main product. This intermediate can undergo a retro‐Mannich reaction to give a pair of intermediates: an imine and 2‐furanol. The remaining pathway directly generates this intermediate pair. The imine and 2‐furanol easily react with each other to afford the product. Thus, all of these stepwise pathways finally converge to give the main product. The rate‐determining step of all five (two concerted and three stepwise) pathways have a common mechanism: concerted SiO bond formation through the nucleophilic attack of a water molecule on the silicon atom followed by proton transfer from the water molecule to the imine. Therefore, these five pathways have comparable barriers and compete with each other.
Ein neuer Ansatz zur nachträglichen Bestimmung der Brandtemperatur von Stahlbetonbauteilen
Authors: Unterderweide Klaus , Rigo Ellen 
Published: October 2013

AbstractFür die Planung von Instandsetzungsmaßnahmen nach einem Brand stellt sich die Frage, welche maximale Temperatur erreicht wurde. Die bisher praktizierten Untersuchungen beschränkten sich auf röntgenographische Messungen oder thermoanalytische Untersuchungen bzw. Porositätsmessungen. Diese Methoden haben den Nachteil, dass die erfahrene Brandtemperatur nicht kontinuierlich nachgewiesen werden kann. Sie decken lediglich enge Temperaturbereiche ab. Im Rahmen der hier vorgestellten Untersuchungen wurde erstmals die Infrarot‐Spektroskopie eingesetzt. Der große Vorteil hierbei ist, dass auch nicht‐kristalline (amorphe) Anteile erfasst werden können. Es konnte gezeigt werden, dass die Temperatur die Lage der Si‐O‐Streckschwingungsbande der festigkeitsbestimmenden Calciumsilikathydrat‐Phasen (CSH‐Phasen) beeinflusst, wobei diese sich irreversibel mit zunehmender Temperatur zu niedrigeren Wellenzahlen verschiebt. Die Verschiebung ist vermutlich auf eine Depolymerisation der kettenförmigen Si‐O‐Si‐Ketten der CSH‐Phasen bis hin zum Monosilikat b‐C2S zu erklären.A new approach to determine the maximum temperature of fire damaged reinforced concrete building elements. When a fire has damaged a reinforced concrete structure, an engineer has to work out a proper and efficient repair strategy. Because of the effect of the fire on the structural properties of the concrete and the steel, it is important to know the maximum temperature reached. Actually, methods like x‐ray diffraction, thermogravimetry and mercury intrusion are used for this investigation. These methods can only determine a few temperature steps and can’t provide a stepless thermometer. From these methods no step‐less heat exposure can be drawn. For the first time the FTIR spectroscopy was used to determine the maximum temperature. This method has the advantage that the amorphous structures can be examined. It is shown that the wavenumber of the Si‐O‐stretching mode is a function of the temperature. The wavenumber decreases with increasing temperature. It should be noted that this correlation is independent from the time the sample is exposed to temperature. The decreases of the wavenumber is probably due to the fact that the Si‐O‐Si‐chains of the CSH phases do depolymerise until monosilicate b‐C2S.
23. Dresdner Brückenbausymposium – nach wie vor mit hoher Beteiligung
Authors: Stritzke Jürgen 
Published: October 2013

AbstractErstmals fand das Dresdner Brückenbausymposium an einer Exzellenzuniversität statt, denn die TU Dresden gehört zu den elf Universitäten, die in der 2. Phase der Exzellenzinitiative als Exzellenz‐Universitäten ausgewählt wurden. Aber nicht nur im bundesweiten Wettbewerb um die Exzellenzinitiative war die TU Dresden erfolgreich. Das Bundesministerium für Bildung und Forschung (BMBF) teilte im März vergangenen Jahres mit, dass die TU Dresden die erfolgreichste Hochschule bei der Einwerbung von BMBF‐Projekten sei. Laut Statistischem Bundesamt gehört die TU Dresden zu den Top 3 bei der Einwerbung von Drittmitteln überhaupt. Im aktuellen DFG‐Förderatlas hat sich die TU Dresden um fünf Plätze verbessern können. Außerdem konnte sich die TU Dresden als die Nummer 1 der deutschen Universitäten auf dem Gebiet der Nanotechnologie beweisen (nach einem Material des Rektors der TU Dresden).Pünktlich 9 Uhr eröffnete Univ.‐Prof. Dr.‐Ing. Dr.‐Ing. E.h. Manfred Curbach, Direktor des Instituts für Massivbau der TU Dresden, am 12. März 2013 das 23. Dresdner Brückenbausymposium, nachdem schon am Vorabend das Treffen der Brückenbauer im Foyer des hiesigen Hörsaalzentrums stattgefunden hatte.1 250 Gäste aus dem In‐ und Ausland waren gekommen, das Neueste über Planung, Bauausführung, Instandsetzung und Ertüchtigung von Brücken zu hören.
When Fluency Signals Truth: Prior Successful Reliance on Fluency Moderates the Impact of Fluency on Truth Judgments
Authors: Scholl Sabine G. , Greifeneder Rainer , Bless Herbert 
Published: October 2013

ABSTRACTRepeated statements are more frequently judged to be true. One position relates this so‐called “truth effect” to metacognitive experiences of fluency, suggesting that repeated statements are more frequently judged to be true because they are processed more fluently. Although most prior research focused on why repetition influences truth judgments, considerably less is known about when fluency is used as information. The present research addresses this question and investigates whether reliance on fluency is moderated by learning experiences. Specifically, we focus on changes in the reliance on fluency over the course of time. A series of experiments reveals that fluency is more likely to be used in truth judgments when previous reliance on fluency has resulted in valid judgments, compared with when previous reliance on fluency was misleading. These findings suggest that reliance on fluency in judgments is a finely tuned process that takes prior experiences with fluency‐based judgments into account. Copyright © 2013 John Wiley & Sons, Ltd.
ATP‐binding cassette transporters in liver
Authors: Wlcek Katrin , Stieger Bruno 
Published: October 2013

AbstractThe human ATP‐binding cassette (ABC) superfamily consists of 48 members with 14 of them identified in normal human liver at the protein level. Most of the ABC members act as ATP dependent efflux transport systems. In the liver, ABC transporters are involved in diverse physiological processes including export of cholesterol, bile salts, and metabolic endproducts. Consequently, impaired ABC transporter function is involved in inherited diseases like sitosterolemia, hyperbilirubinemia, or cholestasis. Furthermore, altered expression of some of the hepatic ABCs have been associated with primary liver tumors. This review gives a short overview about the function of hepatic ABCs. Special focus is addressed on the localization and ontogenesis of ABC transporters in the human liver. In addition, their expression pattern in primary liver tumors is discussed. © 2013 BioFactors, 40(2):188–198, 2014
Alterations in human muscle protein metabolism with aging: Protein and exercise as countermeasures to offset sarcopenia
Authors: Churchward‐Venne Tyler A. , Breen Leigh , Phillips Stuart M. 
Published: October 2013

AbstractAging is associated with a reduction in skeletal muscle mass—sarcopenia—the etiology of which is multifactorial. One mechanism is that aging has, as one of its hallmarks, a reduced sensitivity of skeletal muscle to the normally potent anabolic effects of protein feeding and resistance exercise, and to the anticatabolic effects of insulin, the combination of which has been termed “anabolic resistance.” However, this reduced sensitivity of skeletal muscle to anabolic stimuli may, in some cases, be overcome by providing a greater quantity of the nutrition and/or exercise stimulus. Daily habitual physical activity appears to be a primary determinant of anabolic resistance as we have recently shown that as little as 14 days of reduced ambulatory activity was sufficient to induce anabolic resistance in the elderly by attenuating the postprandial increase in muscle protein synthesis (MPS). The etiology of anabolic resistance is complex and may include alterations in amino acid uptake/utilization, cell signaling status, muscle blood flow, and microvascular perfusion (impacting amino acid delivery and availability). Further, there appears to be sexual dimorphism with advancing age in the response of MPS to amino acid/insulin provision. Maintenance of physical activity during aging is of fundamental importance for skeletal muscle to allow it to appropriately respond to the anabolic effects of nutrition. © 2013 BioFactors, 40(2):199–205, 2014
Time‐resolved microfluorimetry: An alternative method for free radical and metabolic rate detection in microalgae
Authors: Bijoux Amadine , Ribou Anne‐Cécile 
Published: October 2013

AbstractOxidative stress leads to an increase in the production of reactive oxygen species in cells and can be induced by environmental factors. To study free radical production in living microalgae, we use time‐resolved microfluorimetry, a technology adopted from research on mammalian cells. In contrast to fluorescent probe‐based measurements that rely on intensity changes, our sensor detects the presence of free radicals through collisional quenching, and is insensitive to most artifacts commonly observed with intensity‐based methods. A new probe, 1‐pyrenebutanol allows estimation of free radicals production in the green microalga Tetraselmis ssp., for the first time. In addition, our method monitors simultaneously metabolic rate (through bound‐free NAD(P)H ratio). Our results show that free radical production in algal cells is correlated to algal aging, and that during cell growth phases both intracellular free radicals and metabolic activity increase. Concerning thermal stress, we observe that rapid and low temperature changes (<10°C) induce instantaneously an increase in ROS production. Our findings provide new insights into the production of free radicals in response to environmental stresses in unicellular green algae.
Natural products – modifying metabolite pathways in plants
Authors: Staniek Agata , Bouwmeester Harro , Fraser Paul D. , Kayser Oliver , Martens Stefan , Tissier Alain , van der Krol Sander , Wessjohann Ludger , Warzecha Heribert 
Published: October 2013

AbstractThe diversity of plant natural product (PNP) molecular structures is reflected in the variety of biochemical and genetic pathways that lead to their formation and accumulation. Plant secondary metabolites are important commodities, and include fragrances, colorants, and medicines. Increasing the extractable amount of PNP through plant breeding, or more recently by means of metabolic engineering, is a priority. The prerequisite for any attempt at metabolic engineering is a detailed knowledge of the underlying biosynthetic and regulatory pathways in plants. Over the past few decades, an enormous body of information about the biochemistry and genetics of biosynthetic pathways involved in PNPs production has been generated. In this review, we focus on the three large classes of plant secondary metabolites: terpenoids (or isoprenoids), phenylpropanoids, and alkaloids. All three provide excellent examples of the tremendous efforts undertaken to boost our understanding of biosynthetic pathways, resulting in the first successes in plant metabolic engineering. We further consider what essential information is still missing, and how future research directions could help achieve the rational design of plants as chemical factories for high‐value products.
Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution
Authors: Zhu Linjiang , Cai Zhen , Zhang Yanping , Li Yin 
Published: October 2013

AbstractMicrobial tolerance to toxic products and biomass hydrolysates is a challenge for the production of fuels and chemicals from renewable resources. To improve cellular tolerance to these environmental stresses, a novel adaptive evolutionary strategy based on stress‐induced mutagenesis (SIM) was developed using non‐dividing cells. The concept of this method was proved using Escherichia coli FC40 as a model strain, which was used to quantitatively evaluate the rate of SIM. By deleting either the mutL or mutS gene to disturb the mismatch repair activity of the host cells, the SIM rate under stressful conditions increased by 92‐ and 57‐fold, respectively. A periodic SIM‐based adaptive evolution procedure, which synchronized the mutagenesis and the selection process in a single plate‐incubation step, was then developed using the mutL‐deleted mutant. E. coli mutants tolerant to high concentrations of butanol (13 g/L), NaCl (95 g/L), and high temperature (50°C) were obtained. These results indicate that stress‐induced adaptive evolution in non‐dividing cells is an effective approach that can improve microbial tolerance against various stresses and generate robust microbial strains suitable for production of fuels and chemicals.
The profiling and identification of the metabolites of (+)‐catechin and study on their distribution in rats by HPLC‐DAD‐ESI‐IT‐TOF‐MSn technique
Authors: Liang Jing , Xu Feng , Zhang Ya‐Zhou , Zang Xin‐Yu , Wang Dan , Shang Ming‐Ying , Wang Xuan , Chui De‐Hua , Cai Shao‐Qing 
Published: October 2013

ABSTRACT(+)‐Catechin, a potential beneficial compound to human health, is widely distributed in plants and foods. A high‐performance liquid chromatography with diode array detector and combined with electrospray ionization ion trap time‐of‐flight multistage mass spectrometry method was applied to profile and identify the metabolites of (+)‐catechin in rats and to study the distribution of these metabolites in rat organs for the first time. In total, 51 phase II metabolites (44 new) and three phase I metabolites were tentatively identified, comprising 16 (+)‐catechin conjugates, 14 diarylpropan‐2‐ol metabolites, 6 phenyl valerolactone metabolites and 18 aromatic acid metabolites. Further, 19 phase II metabolites were new compounds. The in vivo metabolic reactions of (+)‐catechin in rats were found to be ring‐cleavage, sulfation, glucuronidation, methylation, dehydroxylation and dehydrogenation. The numbers of detected metabolites in urine, plasma, small intestine, kidney, liver, lung, heart, brain and spleen were 53, 23, 27, 9, 7, 5, 3, 2 and 1, respectively. This indicated that small intestine, kidney and liver were the major organs for the distribution of (+)‐catechin metabolites. In addition, eight metabolites were found to possess bioactivities according to literature. These results are very helpful for better comprehension of the in vivo metabolism of (+)‐catechin and its pharmacological actions, and also can give strong indications on the effective forms of (+)‐catechin in vivo. Copyright © 2013 John Wiley & Sons, Ltd.
Triterpenoids from the Stem Bark of Melia toosendan and Determination of Their Absolute Configurations at C(24)
Authors: Zhang Yi , Tang Chun‐Ping , Ke Chang‐Qiang , Yao Sheng , Ye Yang 
Published: October 2013

AbstractSix new triterpenoids, meliasenins S–X (1–6, resp.), were isolated from the stem bark of Melia toosendan. Their structures were elucidated by mass spectrometry, NMR experiments, and comparison with the known compounds. Particularly, the absolute configuration at C(24) in new compounds was determined through their CD spectra of the [Pr(FOD)3] complex (fod=1,1,1,2,2,3,3,7,7,7‐decafluoroheptane‐4,6‐dione) in CCl4, as well as by using Mosher's method.
Evaluation of Adsorption Kinetics and Equilibrium for the Removal of Benzene by Modified Diatomite
Authors: Khalighi Sheshdeh R. , Khosravi Nikou M. R. , Badii K. , Mohammadzadeh S. 
Published: October 2013

AbstractIn order to find alternative low‐cost adsorbents for volatile organic liquids, the effectiveness of nickel oxide nanoparticles‐modified diatomite (NONMD) in removing benzene was assessed. The impact of different operation parameters such as pH, contact time, initial benzene concentration, and adsorption dosage on the adsorption process was evaluated and optimum experimental conditions were identified. Surface area and morphology of the nanoparticles were characterized by scanning electron microscopy (SEM), Brunauer‐Emmett‐Teller (BET) isotherms, X‐ray diffraction (XRD), Fourier transform infrared (FTIR), and energy dispersive X‐ray (EDX) analysis. The isotherm and kinetics effect of the adsorbent were evaluated.
Tunable Spin‐Crossover Behavior of the Hofmann‐like Network {Fe(bpac)[Pt(CN)4]} through Host–Guest Chemistry
Authors: Bartual‐Murgui Carlos , Akou Amal , Shepherd Helena J. , Molnár Gábor , Real J. Antonio , Salmon Lionel , Bousseksou Azzedine 
Published: October 2013

AbstractA study of the spin‐crossover (SCO) behavior of the tridimensional porous coordination polymer {Fe(bpac)[Pt(CN)4]} (bpac=bis(4‐pyridyl)acetylene) on adsorption of different mono‐ and polyhalobenzene guest molecules is presented. The resolution of the crystal structure of {Fe(bpac)[Pt(CN)4]}⋅G (G=1,2,4‐trichlorobenzene) shows preferential guest sites establishing π⋅⋅⋅π stacking interactions with the host framework. These host–guest interactions may explain the relationship between the modification of the SCO behavior and both the chemical nature of the guest molecule (electronic factors) and the number of adsorbed molecules (steric factors).
Nickel Hydroxide Nanoparticle Activated Semi‐metallic TiO2 Nanotube Arrays for Non‐enzymatic Glucose Sensing
Authors: Gao Zhi‐Da , Guo Jing , Shrestha Nabeen K , Hahn Robert , Song Yan‐Yan , Schmuki Patrik 
Published: October 2013

AbstractSemi‐metallic TiO2 nanotube arrays (TiOxCy NTs) have been decorated uniformly with Ni(OH)2 nanoparticles without the aid of a polymer binder. The resulting hybrid nanotube arrays exhibit excellent catalytic activity towards non‐enzymatic glucose electro‐oxidation. The anodic current density of the glucose oxidation is significantly improved compared with traditional TiO2 nanotubes decorated with Ni(OH)2. Moreover, the Ni(OH)2/TiOxCy NT‐based electrode shows a fast response, high sensitivity, wide linear range, good selectivity and stability towards glucose electro‐oxidation, and thus provides a promising and cost‐effective sensing platform for non‐enzymatic glucose detection.
Development of Luminescent Coelenterazine Derivatives Activatable by β‐Galactosidase for Monitoring Dual Gene Expression
Authors: Lindberg Eric , Mizukami Shin , Ibata Keiji , Miyawaki Atsushi , Kikuchi Kazuya 
Published: October 2013

AbstractTwo bioluminogenic caged coelenterazine derivatives (bGalCoel and bGalNoCoel) were designed and synthesized to detect β‐galactosidase activity and expression by means of bioluminescence imaging. Our approach addresses the instability of coelenterazine by introducing β‐galactose caging groups to block the auto‐oxidation of coelenterazine. Both probes contain β‐galactosidase cleavable caging groups at the carbonyl group of the imidazo–pyrazinone moiety. One of the probes in particular, bGalNoCoel, displayed a fast cleavage profile, high stability, and high specificity for β‐galactosidase over other glycoside hydrolases. bGalN‐oCoel could detect β‐galactosidase activity in living HEK‐293T cell cultures that expressed a mutant Gaussia luciferase. It was determined that coelenterazine readily diffuses in and out of cells after uncaging by β‐galactosidase. We showed that this new caged coelenterazine derivative, bGalNoCoel, could function as a dual‐enzyme substrate and detect enzyme activity across two separate cell populations.
Anion‐Templated Assembly and Magnetocaloric Properties of a Nanoscale {Gd38} Cage versus a {Gd48} Barrel
Authors: Guo Fu‐Sheng , Chen Yan‐Cong , Mao Ling‐Ling , Lin Wei‐Quan , Leng Ji‐Dong , Tarasenko Róbert , Orendáč Martin , Prokleška Jan , Sechovský Vladimír , Tong Ming‐Liang 
Published: October 2013

AbstractThe comprehensive study reported herein provides compelling evidence that anion templates are the main driving force in the formation of two novel nanoscale lanthanide hydroxide clusters, {Gd38(ClO4)6} (1) and {Gd48Cl2(NO3)} (2), characterized by single‐crystal X‐ray crystallography, infrared spectroscopy, and magnetic measurements. {Gd38(ClO4)6}, encapsulating six ClO4− ions, features a cage core composed of twelve vertex‐sharing {Gd4} tetrahedrons and one Gd⋅⋅⋅Gd pillar. When Cl− and NO3− were incorporated in the reaction instead of ClO4−, {Gd48Cl2(NO3)} is obtained with a barrel shape constituted by twelve vertex‐sharing {Gd4} tetrahedrons and six {Gd5} pyramids. What is more, the cage‐like {Gd38} can be dynamically converted into the barrel‐shaped {Gd48} upon Cl− and NO3− stimulus. To our knowledge, it is the first time that the linear M‐O‐M′ fashion and the unique μ8‐ClO4− mode have been crystallized in pure lanthanide complex, and complex 2 represents the largest gadolinium cluster. Both of the complexes display large magnetocaloric effect in units of J kg−1 K−1 and mJ cm−3 K−1 on account of the weak antiferromagnetic exchange, the high NGd/MW ratio (magnetic density), and the relatively compact crystal lattice (mass density).
Luminescent Cyanoruthenate(II)Diimine and Cyanoruthenium(II)Diimine Complexes
Authors: Feng Hua , Zhang Feng , Lai Sze‐Wing , Yiu Shek‐Man , Ko Chi‐Chiu 
Published: October 2013

AbstractTo improve the emission and excited‐state properties of luminescent cyanometalates, new classes of highly solvatochromic luminescent cyanoruthenium(II) and cyanoruthenate(II) complexes of the general formulae [Ru(PR3)2(CN)2($\widehat{NN}$)] and K[Ru(PR3)(CN)3($\widehat{NN}$)], respectively, were developed. These complexes could be readily synthesized through the ligand‐substitution reaction of K2[Ru(CN)4(PR3)2] with a diimine ligand. The geometrical isomerism of these complexes was characterized by using various spectroscopic techniques. Their photophysical properties, solvatochromism, and electrochemistry have also been investigated. Our detailed study showed that many of these complexes exhibited extremely environmentally sensitive emissions and significantly improved emission quantum efficiencies and lifetimes compared with the well‐studied tetracyanoruthenate systems.