bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant microRNAs: master regulator of gene expression mechanism
Authors: Datta Riddhi , Paul Soumitra 
Published: June 2015

AbstractSeveral signaling molecules critically regulate the physiological responses in plants. Among them, miRNAs, generally 21–24 nucleotides long, are widely distributed in different plant species and play as key signaling intermediates in diverse physiological responses. The mature miRNAs are synthesized from MIR genes by RNA polymerase II and processed by Dicer‐like (DCL) protein family members associated with some accessory protein molecules. The processed miRNAs are transported to the cytoplasm from the nucleus by specific group of transporters and incorporated into RNA‐induced silencing complex (RISC) for specific mRNA cleavage. MicroRNAs can suppress the diverse gene expression, depending on the sequence complementarity of the target transcript except of its own gene. Besides, miRNAs can modulate the gene expression by DNA methylation and translational inhibition of the target transcript. Different classes of DCLs and Argonaute proteins (AGOs) help the miRNAs‐mediated gene silencing mechanism in plants.
Adipose progenitor cells reside among the mature adipocytes: morphological research using an organotypic culture system
Authors: Anayama Hisashi , Fukuda Ryo , Yamate Jyoji 
Published: June 2015

AbstractThe precise localization and biological characteristics of the adipose progenitor cells are still a focus of debate. In this study, the localization of the adipose progenitor cells was determined using an organotypic culture system of adipose tissue slices. The tissue slices of subcutaneous white adipose tissue from rats were placed on a porous membrane and cultured at the interface between air and the culture medium for up to 5 days with or without adipogenic stimulation. The structure of adipose tissue components was sufficiently preserved during the culture and, following adipogenic stimulation with insulin, dexamethasone, and 3‐isobutyl‐1‐methylxanthine, numerous multilocular adipocytes appeared in the interstitium among the mature adipocytes. Histomorphological 3‐D observation using confocal laser microscopy revealed the presence of small mesenchymal cells containing little or no fat residing in the perivascular region and on the mature adipocytes and differentiation from the pre‐existing mesenchymal cells to multilocular adipocytes. Immunohistochemistry demonstrated that these cells were initially present within the fibronectin‐positive extracellular matrix (ECM). The adipose differentiation of the mesenchymal cells was confirmed by the enhanced expression of C/EBP‐β suggesting adipose differentiation and the concurrent advent of CD105‐expressing mesenchymal cells within the interstitium of the mature adipocytes. Based on the above, the mesenchymal cells embedded in the ECM around the mature adipocytes were confirmed to be responsible for adipogenesis because the transition of the mesenchymal cells to the stem state contributed to the increase in the number of adipocytes in rat adipose tissue.
Successful treatment of hemochromatosis with renal tubular dysgenesis in a preterm infant
Authors: Koura Uta , Horikawa Shinjiro , Okabe Mako , Kawasaki Yukako , Makimoto Masami , Mizuta Koichi , Yoshida Taketoshi 
Published: June 2015

Key Clinical MessageWe report the first surviving case of neonatal hemochromatosis with renal tubular dysgenesis. Renal failure was treated with peritoneal dialysis. Although hepatic failure from neonatal hemochromatosis was progressive, repeated exchange transfusions improved jaundice and coagulopathy. The patient gained weight and received a liver transplantation from her father.
A giant abdominal hematoma caused by seatbelt injury led to the development of shock
Authors: Nishino Tomoya , Morita Seiji , Sakurai Keiji , Watanabe Yasue 
Published: June 2015

Key Clinical MessageTrauma to soft tissues is an important consideration in cases of seatbelt injury, as soft‐tissue injury can cause shock. Careful observation for hours in the clinic at least, along with appropriate imaging studies, is necessary if signs of a seatbelt injury exist.
Sulfur‐Doped Carbon Aerogel as a Metal‐Free Oxygen Reduction Catalyst
Authors: Seredych Mykola , László Krisztina , Bandosz Teresa J. 
Published: June 2015

AbstractResorcinol‐formaldehyde‐based carbon aerogels were modified by treatment with H2S at 650 and 800 °C and used as catalysts for the oxygen reduction reaction (ORR) in an alkaline medium. On the material treated at high temperature, the electron transfer number was close to 4 e− and the onset potential for the ORR was shifted to a more positive value. An excellent tolerance to methanol crossover was also detected. The treatment resulted in sulfur doping in the form of thermally stable thiophenic compounds, which increased the surface hydrophobicity. This sulfur leads to a positive charge on the carbon atoms, which are the reaction sites. The hydrophobicity of the surface enhances the withdrawal of O2 from the electrolyte and its adsorption on the surface. The specific micro‐/mesoporosity contributes to a high dispersion of sulfur heteroatoms on the surface and to the accessibility of the surface sites to the electrolyte and thus to oxygen dissolved in water.
Enhanced Chemical Reactivity of Pristine Graphene Interacting Strongly with a Substrate: Chemisorbed Carbon Monoxide on Graphene/Nickel(1 1 1)
Authors: Smerieri Marco , Celasco Edvige , Carraro Giovanni , Lusuan Angelique , Pal Jagriti , Bracco Gianangelo , Rocca Mario , Savio Letizia , Vattuone Luca 
Published: June 2015

AbstractGraphene is usually considered a chemically inert material. Theoretical studies of CO adsorption on free‐standing graphene predict quite low adsorption energies (<0.1 eV). However, we show here by vibrational spectroscopy and scanning tunneling microscopy that the nondissociative chemisorption of CO occurs at cold, pristine graphene grown on Ni(1 1 1). The CO adlayer remains stable up to 125 K, although some coverage survives flashes to 225 K. This unexpected result is explained qualitatively by the modification of the density of states close to the Fermi energy induced by the relatively strong graphene–substrate interaction. The value of the adsorption energy allows us to estimate an equilibrium coverage of the order of 0.1 monolayers at 10 mbar pressure, which thus paves the way for the use of graphene as a catalytically active support under realistic conditions.
MOR/SBA‐15 Composite Catalysts with Interconnected Meso/Micropores for Improved Activity and Stability in Isopropylation of Naphthalene
Authors: Banu Marimuthu , Lee Young Hye , Magesh Ganesan , Nam Chang‐Mo , Lee Jae Sung 
Published: June 2015

AbstractThe isopropylation of naphthalene with isopropyl alcohol was studied over composites of MOR/SBA‐15 in a high‐pressure, fixed‐bed reactor. The MOR catalyst showed a high 2,6‐/2,7‐diisopropyl naphthalene (DIPN) ratio of 1.75, but a low naphthalene conversion (54 %) and fast deactivation of the catalyst. The composites of MOR/SBA‐15 were prepared by a hydrothermal recrystallization process to obtain hierarchical micro/mesopores. During the process, MOR recrystallized in the mesopores of SBA‐15, the structure of which was stabilized by carbon coating formed on the pore walls as a template. The best prepared MOR/SBA‐15 catalyst achieved a high conversion of 85 %, high stability, and less coking, while maintaining the high 2,6‐/2,7‐DIPN ratio (≈1.8). The modified micro/mesopore structure allowed facile diffusion of bulky molecules to and from active catalytic sites located in the small MOR pores as a result of the connection between the two types of pores in the MOR/SBA‐15 composite.
Influence of Different Palladium Precursors on the Properties of Solution‐Combustion‐Synthesized Palladium/Ceria Catalysts for Methane Combustion
Authors: Colussi Sara , Gayen Arup , Boaro Marta , Llorca Jordi , Trovarelli Alessandro 
Published: June 2015

AbstractA series of Pd/CeO2 catalysts was prepared by solution combustion synthesis (SCS) using different Pd precursors. The powders were characterized by complementary techniques such as BET surface area measurements, X‐Ray diffraction analysis, X‐Ray photoelectron spectroscopy, temperature‐programmed reduction, temperature‐programmed oxidation, and high‐resolution TEM. The results obtained evidenced the formation of a Pd‐Ce solid solution on all SCS samples. This solid solution is in the form of an ordered supercell structure only in the SCS catalyst prepared from palladium nitrate. This was correlated to the heat of reaction between Pd(NO3)2 and the fuel. The samples were tested for methane catalytic combustion, and the reaction rates on all SCS samples were approximately twice that of the impregnated counterpart, irrespective of the precursor. This was attributed to the presence of the Pd‐O‐Ce solid solution, which gave rise to strong Pd–ceria interactions.
Performance Evaluation of Two High‐Shear Impellers in an Unbaffled Stirred Tank
Authors: Ramírez‐Gómez Ruben , García‐Cortés Daniel , Martínez‐de Jesús Gaston , González‐Brambila Margarita M. , Alonso Alejandro , Martínez‐Delgadillo Sergio A. , Ramírez‐Muñoz Jorge 
Published: June 2015

AbstractHigh‐shear impellers (HSIs) are mixers used in industrial stirred tanks to incorporate powders into liquids and break down particle agglomerates. A detailed numerical study of two commercial ring‐style HSIs of laboratory scale was carried out and their performance was compared with the Rushton turbine (RT). It was found that power and pumping numbers or their ratio cannot be simply connected for properly selecting an impeller in applications where highly localized viscous dissipation is desirable. The ratio of the average viscous dissipation in the impeller swept volume to the mean in the entire volume at two constant values of power input turned out to be lower for HSIs compared to that evaluated for RT. However, at higher power input, the dimensionless average viscous dissipation in the blade swept volume was found to be similar for the HSI of two rings and the RT, corroborating the high local viscous dissipation of this HSI when operated at higher speeds.
Effects of Surfactants on Mass Transfer from Single Carbon Dioxide Bubbles in Vertical Pipes
Authors: Aoki Jiro , Hayashi Kosuke , Hosokawa Shigeo , Tomiyama Akio 
Published: June 2015

AbstractMass transfer from single fully contaminated carbon dioxide bubbles rising through vertical pipes was measured to investigate the effects of surfactants. The diameter ratio of the bubble diameter to the pipe diameter was varied to cover various bubble shapes from ellipsoidal to Taylor bubbles. Triton X‐100 and 1‐octanol served as surfactants. The mass transfer rates, kL, of contaminated bubbles in the ellipsoidal regime were smaller than those of clean bubbles due to the interface immobilization. The kL of Taylor bubbles contaminated with Triton X‐100 and 1‐octanol showed varying trends because of the difference in the surfactant distributions at the bubble interfaces which strongly depend on the Hatta number. The Sherwood numbers of contaminated bubbles were well correlated by introducing the bubble diameter, at which the bubble shape transits from ellipsoidal to Taylor bubbles.
Power Draw and Gas‐Liquid Mass Transfer Characteristics of a Stirred‐Tank Reactor with Draft Tube Configuration
Authors: Lueske Juergen , Kar Kishore , Piras Luciano , Pressler Jim 
Published: June 2015

AbstractStirred‐tank reactors (STR), in which gas and liquid phases make intimate contact for mass transfer, are quite common in chemical processes. Mechanical agitation enhances the mixing performance and the oxygen transfer capability in bio‐STR, but they cannot be aerated at high rates because of impeller flooding. Another type of reactor widely used in bioprocessing is the airlift bioreactor, which consists of a draft tube and operates with an internal airlift loop. In this work, the mass transfer characteristics of a draft tube‐impeller agitation system (combination of a conventional airlift and a stirred bioreactor) were investigated in a large‐scale tank. The draft tube design configuration shows superior mass transfer performance compared to a conventional down‐pumping agitation system consisting of a Rushton turbine combined with a pitched‐blade turbine.
Determination of Particle Size Distributions in Multiphase Systems Containing Nonspherical Fluid Particles
Authors: Panckow Robert P. , Comandè Giorgio , Maaß Sebastian , Kraume Matthias 
Published: June 2015

AbstractThe presented results are obtained by means of an automated image analysis software capable of measuring particle diameters in photographs taken in situ by a 2D photo‐optical measurement device. Initially, the applicability of this measurement method must be proven for fluid particle systems on the basis of spherical‐shaped particles. As a first approach in targeting the issue of irregularly shaped fluid particles, a pure gas‐liquid system is analyzed to investigate the influence of the variation of operating parameters. In the second step, the spherical shape is changed by reducing the surface‐active auxiliaries. The usage of shape factors helps to interpret the appearance of the 2D projected objects. By examining the capabilities and limitations, it is demonstrated that the size of fluid particles can be detected online and in situ in order to analyze and control the particular chemical process.
An Alternative Approach to PEPPSI Catalysts: From Palladium Isonitriles to Highly Active Unsymmetrically Substituted PEPPSI Catalysts
Authors: Zeiler Anna , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K. 
Published: June 2015

AbstractA series of new pyridine‐enhanced precatalyst preparation, stabilization, and initiation (PEPPSI)‐type complexes bearing different types of carbene ligands was prepared by the modular and convergent template synthesis strategy. Nitrogen acyclic carbenes, saturated and unsaturated five‐membered NHC, saturated six‐membered NHCs, and five‐membered N‐heterocyclic oxo‐carbene (NHOC) ligands on palladium were prepared this way. These new organometallic compounds then were tested in Suzuki and Negishi cross‐coupling reactions by using substrates with one or two substituents in ortho‐position of the new CC bond being formed. Both aryl chlorides and bromides were tested as coupling partners. In some cases, the new ligands gave results similar to Organ’s successful IPr‐based and IPent‐based PEPPSI derivatives, with aryl bromides 0.05 mol % catalyst load still gave satisfactory results, with aryl chlorides 0.5 mol % were needed.
Bis[(dialkylamino)cyclopropenimine]‐Stabilized PIII‐ and PV‐Centered Dications
Authors: Kozma Ágnes , Rust Jörg , Alcarazo Manuel 
Published: June 2015

AbstractThe treatment of bis[(dialkylamino)cyclopropenimines] with dihalophosphines in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) to form diimine‐stabilized PIII‐centered dications is reported. The structures of the new compounds were determined by using X‐ray diffraction analysis and their donor abilities as ligands evaluated through electrochemical methods. Despite the two positive charges that they bear, these compounds depict intermediate behavior between that of phosphines and phosphites. The coordination of the [L2PR]2+ moiety to AuI and AgI is also reported. Even more surprisingly, these phosphorus centers can be oxidized to the corresponding PV dications in the presence of strong oxidants such as peroxides or XeF2.
Coronenetetraimide‐Centered Cruciform Pentamers Containing Multiporphyrin Units: Synthesis and Sequential Photoinduced Energy‐ and Electron‐Transfer Dynamics
Authors: Hasobe Taku , Ida Koichi , Sakai Hayato , Ohkubo Kei , Fukuzumi Shunichi 
Published: June 2015

AbstractA series of coronenetetraimide (CorTIm)‐centered cruciform pentamers containing multiporphyrin units, in which four porphyrin units are covalently linked to a CorTIm core through benzyl linkages, were designed and synthesized to investigate their structural, spectroscopic, and electrochemical properties as well as photoinduced electron‐ and energy‐transfer dynamics. These systems afforded the first synthetic case of coroneneimide derivatives covalently linked with dye molecules. The steady‐state absorption and electrochemical results indicate that a CorTIm and four porphyrin units were successfully characterized by the corresponding reference monomers. In contrast, the steady‐state fluorescence measurements demonstrated that strong fluorescence quenching relative to the corresponding monomer units was observed in these pentamers. Nanosecond laser flash photolysis measurements revealed the occurrence of intermolecular electron transfer from triplet excited state of zinc porphyrins to CorTIm. Femtosecond laser‐induced transient absorption measurements for excitation of the CorTIm unit clearly demonstrate the sequential photoinduced energy and electron transfer between CorTIm and porphyrins, that is, occurrence of the initial energy transfer from CorTIm (energy donor) to porphyrins (energy acceptor) and subsequent electron transfer from porphyrins (electron donor) to CorTIm (electron acceptor) in these pentamers, whereas only the electron‐transfer process from porphyrins to CorTIm was observed when we mainly excite porphyrin units. Finally, construction of high‐order supramolecular patterning of these pentamers was performed by utilizing self‐assembly and physical dewetting during the evaporation of solvent.
Enhanced Photocatalytic Activity of MIL‐125 by Post‐Synthetic Modification with CrIII and Ag Nanoparticles
Authors: Abdelhameed Reda M. , Simões Mário M. Q. , Silva Artur M. S. , Rocha João 
Published: June 2015

AbstractNH2‐MIL‐125, [Ti8O8(OH)4(bdc‐NH2)6] (bdc2−=1,4‐benzene dicarboxylate) is a highly porous metal–organic framework (MOF) that has a band gap lying within the ultraviolet region at about 2.6 eV. The band gap may be reduced by a suitable post‐synthetic modification of the nanochannels using conventional organic chemistry methods. Here, it is shown that the photocatalytic activity of NH2‐MIL‐125 in the degradation of methylene blue under visible light is remarkably augmented by post‐synthetic modification with acetylacetone followed by CrIII complexation. The latter metal ion extends the absorption from the ultraviolet to the visible light region (band gap 2.21 eV). The photogenerated holes migrate from the MOF’s valence band to the CrIII valence band, promoting the separation of holes and electrons and increasing the recombination time. Moreover, it is shown that the MOF’s photocatalytic activity is also much improved by doping with Ag nanoparticles, formed in situ by the reduction of Ag+ with the acetylacetonate pendant groups (the resulting MOF band gap is 2.09 eV). Presumably, the Ag nanoparticles are able to accept the MOF’s photogenerated electrons, thus avoiding electron–hole recombination. Both, the Cr‐ and Ag‐bearing materials are stable under photocatalytic conditions. These findings open new avenues for improving the photocatalytic activity of MOFs.
Fluorescent Dendritic Organogels Based on 2‐(2′‐Hydroxyphenyl)benzoxazole: Emission Enhancement and Multiple Stimuli‐Responsive Properties
Authors: Chen Hui , Feng Yu , Deng Guo‐Jun , Liu Zhi‐Xiong , He Yan‐Mei , Fan Qing‐Hua 
Published: June 2015

AbstractA new highly efficient and versatile poly(benzyl ether) dendritic organogelator HPB‐G1 with 2‐(2′‐hydroxyphenyl)benzoxazole (HPB) at the focal point has been designed and synthesized. HPB‐G1 can form stable organogels toward various apolar and polar organic solvents. Further studies revealed that intermolecular multiple π–π stacking interactions are the main driving forces for the formation of the organogels. Notably, dendron HPB‐G1 exhibited a significantly enhanced emission in the gel state in contrast to weak emission in solution. Most interestingly, these dendritic organogels exhibited multiple stimuli‐responsive behaviors upon exposure to environmental stimuli, including temperature, sonication, shear stress, and the presence of anions, metal cations, acids/bases, thus leading to reversible sol–gel phase transitions.
Driving Helical Packing of a Cyanine Dye on Dendron Nanofiber: Gel‐Shrinkage‐Triggered Chiral H‐Aggregation and Enhanced Enantiodiscrimination
Authors: Qin Long , Xie Fan , Jin Xue , Liu Minghua 
Published: June 2015

AbstractAn intelligent molecular hydrogel with a volume phase transition was constructed to regulate the chiral packing of a well‐known cyanine dye on a dynamically self‐assembled chiral nanofiber by using a pH trigger. During the shrinkage of the gel, the chiral nanofiber hierarchically assembled into a superhelix and simultaneously drove the dye molecules to stack, from a predominantly monomer form, in an unexpected helical H‐aggregation manner. Through such a transformation, the supramolecular chirality of the system was significantly enhanced and a new property of visual discrimination for chiral amines emerged.
Ultraviolet Photolysis Studies on XeO4 in Noble‐Gas and F2 Matrices and the Formation and Characterization of a New XeVIII Oxide, (η2‐O2)XeO3
Authors: Vent‐Schmidt Thomas , Goettel James T. , Schrobilgen Gary J. , Riedel Sebastian 
Published: June 2015

AbstractThe photolytic behavior of the thermochemically unstable xenon(VIII) oxide XeO4 was investigated by UV irradiation in noble‐gas and F2 matrices. Photolysis of Xe16O4 or Xe18O4 in noble‐gas matrices at 365 nm yielded XeO3 and a new xenon(VIII) oxide, namely, (η2‐O2)XeO3, which, along with XeO4, was characterized by matrix‐isolation IR spectroscopy and quantum‐chemical calculations. Calculations of the UV spectrum showed that the photodecomposition is induced by an n→σ* transition, but the nature of the excitation differs when different light sources are used. There is strong evidence for the formation of mobile 1D excited O atoms in the case of excitation at 365 nm, which led to the formation of (η2‐O2)XeO3 by reaction with XeO4. Matrix‐isolation IR spectroscopy in Ne and Ar matrices afforded the natural‐abundance xenon isotopic pattern for the ν3(T2) stretching mode of Xe16O4, and 18O enrichment provided the 16O/18O isotopic shifts of XeO4 and (η2‐O2)XeO3.
Monodisperse AgSbS2 Nanocrystals: Size‐Control Strategy, Large‐Scale Synthesis, and Photoelectrochemistry
Authors: Zhou Bin , Li Mingrun , Wu Yihui , Yang Chi , Zhang Wen‐Hua , Li Can 
Published: June 2015

AbstractWe report an efficient approach to the synthesis of AgSbS2 nanocrystals (NCs) by colloidal chemistry. The size of the AgSbS2 NCs can be tuned from 5.3 to 58.3 nm with narrow size distributions by selection of appropriate precursors and fine control of the experimental conditions. Over 15 g of high‐quality AgSbS2 NCs can be obtained from one single reaction, indicative of the up‐scalability of the present synthesis. The resulting NCs display strong absorptions in the visible‐to‐NIR range and exceptional air stability. The photoelectrochemical measurements indicate that, although the pristine AgSbS2 NC electrodes generate a cathodic photocurrent with a relatively small photocurrent density and poor stability, both of them can be significantly improved subject to CdS surface modification, showing promise in solar energy conversion applications.