bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endogenous retroviruses in mammals: An emerging picture of how ERVs modify expression of adjacent genes
Authors: Isbel Luke , Whitelaw Emma 
Published: June 2012

AbstractEndogenous retrovirsuses (ERVs) have long been known to influence gene expression in plants in important ways, but what of their roles in mammals? Our relatively sparse knowledge in that area was recently increased with the finding that ERVs can influence the expression of mammalian resident genes by disrupting transcriptional termination. For many mammalian biologists, retrotransposition is considered unimportant except when it disrupts the reading frame of a gene, but this view continues to be challenged. It has been known for some time that integration into an intron can create novel transcripts and integration upstream of a gene can alter the expression of the transcript, in many cases producing phenotypic consequences and disease. The new findings on transcriptional termination extend the opportunities for retrotransposons to play a role in human disease.
Luminescence properties of Tb3+ doped Sr2SnO4 green phosphor in UV/VUV regions
Authors: Srinivas M , Rao B Appa , Vithal M , Rao P Raghava 
Published: June 2012

ABSTRACTPolycrystalline Sr2SnO4 phosphors doped with Tb3+ were prepared by conventional solid‐state reaction method. Materials were characterized by powder XRD and EDS techniques. The luminescence properties of these materials were investigated under UV and VUV excitation. Upon excitation at 272 nm, phosphors exhibited intense emissions at 492 and 543 nm due to 5D4 → 7 F6 and 5D4 → 7 F5 transitions of Tb3+ ions, respectively. Materials also exhibited strong emissions from these transitions under VUV excitation at 147, 173 and 230 nm. Quantitative analysis of the spectra indicated probable applications of these phosphors for PDP and other display devices as green emitting phosphors. Copyright © 2012 John Wiley & Sons, Ltd.
Ionic liquids dispersive liquid–liquid microextraction and high‐performance liquid chromatographic determination of irbesartan and valsartan in human urine
Authors: Li Zhiling , Chen Fan , Wang Xuedong , Wang Chengjun 
Published: June 2012

ABSTRACTAn environmentally friendly ionic liquids dispersive liquid–liquid microextraction (IL‐DLLME) method coupled with high‐performance liquid chromatography (HPLC) for the determination of antihypertensive drugs irbesartan and valsartan in human urine samples was developed. The HPLC separations were accomplished in less than 10 min using a reversed‐phase C18 column (250 × 4.60 mm i.d., 5 µm) with a mobile phase containing 0.3 % formic acid solution and methanol (v/v, 3:7; flow rate, 1.0 mL/min). UV absorption responses at 236 nm were linear over a wide concentration range from 50 µg/mL to the detection limits of 3.3 µg/L for valsartan and 1.5 µg/L for irbesartan. The effective parameters on IL‐DLLME, such as ionic liquid types and their amounts, disperser solvent types and their volume, pH of the sample and extraction time were studied and optimized. The developed IL‐DLLME‐HPLC was successfully applied for evaluation of the urine irbesartan and valsartan profile following oral capsules administration. Copyright © 2012 John Wiley & Sons, Ltd.
Substrates of neuropsychological functioning in stimulant dependence: a review of functional neuroimaging research
Authors: Crunelle Cleo L. , Veltman Dick J. , Booij Jan , van Emmerik – van Oortmerssen Katelijne , van den Brink Wim 
Published: June 2012

AbstractStimulant dependence is associated with neuropsychological impairments. Here, we summarize and integrate the existing neuroimaging literature on the neural substrates of neuropsychological (dys)function in stimulant dependence, including cocaine, (meth‐)amphetamine, ecstasy and nicotine dependence, and excessive caffeine use, comparing stimulant abusers (SAs) to nondrug using healthy controls (HCs). Despite some inconsistencies, most studies indicated altered brain activation in prefrontal cortex (PFC) and insula in response to reward and punishment, and higher limbic and anterior cingulate cortex (ACC)/PFC activation during craving and attentional bias paradigms in SAs compared with HCs. Impulsivity in SAs was associated with lower ACC and presupplementary motor area activity compared with HCs, and related to both ventral (amygdala, ventrolateral PFC, insula) and dorsal (dorsolateral PFC, dorsal ACC, posterior parietal cortex) systems. Decision making in SAs was associated with low dorsolateral PFC activity and high orbitofrontal activity. Finally, executive function in SAs was associated with lower activation in frontotemporal regions and higher activation in premotor cortex compared with HCs. It is concluded that the lower activations compared with HCs are likely to reflect the neural substrate of impaired neurocognitive functions, whereas higher activations in SAs compared with HCs are likely to reflect compensatory cognitive control mechanisms to keep behavioral task performance to a similar level as in HCs. However, before final conclusions can be drawn, additional research is needed using neuroimaging in SAs and HCs using larger and more homogeneous samples as well as more comparable task paradigms, study designs, and statistical analyses.
Prevalence, laterality, and comorbidity of hippocampal sclerosis in an autopsy sample
Authors: Zarow Chris , Weiner Michael W. , Ellis William G. , Chui Helena Chang 
Published: June 2012

AbstractHippocampal sclerosis (HS) is a common and often asymmetric neuropathological finding among elderly persons who experience progressive memory loss, but its cause is unknown and it is rarely diagnosed during life. In order to improve both understanding and diagnosis of late‐life HS, bilateral hippocampi and cerebral hemispheres were reviewed in 130 consecutive autopsy cases drawn from a longitudinal study of subjects with subcortical ischemic vascular dementia (IVD), Alzheimer disease (AD) and normal aging. HS was found in 31 of 130 cases (24.5%). Of these, 45% were bilateral, 32% left‐sided, and 23% right‐sided. The majority of HS cases involved the entire rostral‐caudal extent of the hippocampus. However, in 7 cases HS was focal in nature and was only found at or anterior to the lateral geniculate nucleus. In 77% of cases, HS was accompanied by other types of pathology (‘mixed’ HS), but in 23% of cases it was the sole neuropathologic finding (‘pure’ HS). TDP‐43‐positive cytoplasmic inclusions were found in dentate granule cells in 93% of all HS cases, 55% of AD cases with no HS, but 0% of IVD cases with no HS. MRI hippocampal volumes were significantly lower in bilateral HS compared to AD (p < 0.001) and in unilateral HS cases compared to cases with intact hippocampi (p < 0.001).Since HS may occur unilaterally in approximately a quarter of cases, its prevalence may be underestimated if only one cerebral hemisphere is examined. The presence of TDP‐43 inclusions in HS cases, regardless of accompanying pathologies (e.g., AD, IVD, FTLD), is consistent with an underlying neurodegenerative pathogenetic mechanism. Further studies are warranted to determine whether greater severity of hippocampal atrophy on MRI may assist the clinical differentiation of HS from AD.
A promising randomized trial of a new therapy for obsessive–compulsive disorder
Authors: Hu Xian‐Zhang , Wen You‐Sheng , Ma Jian‐Dong , Han Dong‐Ming , Li Yu‐Xia , Wang Shu‐Fan 
Published: June 2012

AbstractPharmacotherapy and cognitive–behavioral therapy (CBT) are currently the most effective interventions for treating obsessive–compulsive disorder (OCD). These treatments, however, are time consuming and in some cases the patients do not show significant improvement. In all, 30%–60% of OCD patients do not respond adequately to pharmacotherapy and 20%–40% of OCD patients who complete CBT do not improve significantly, suggesting a more efficacious approach is needed. The objectives of this study are to demonstrate an efficacious pharmacotherapy plus psychotherapy, named cognitive–coping therapy (CCT), for OCD and to investigate the efficacy of this approach in a larger sample size. Therefore, a total of 108 patients with OCD were randomly allocated into three groups: pharmacotherapy (N = 38), pharmacotherapy plus CBT (PCBT, N = 34), and pharmacotherapy plus CCT (PCCT, N = 36). The severity of symptoms and the patients' functioning were assessed pretreatment and after 7, 14, 21 days, and 1‐, 3‐, 6‐, and 12‐month treatment using the Yale‐Brown Obsessive Compulsive Scale and Global Assessment of Functioning (GAF). Compared with the pharmacotherapy and PCBT groups, the severity of OCD symptoms was significantly reduced (P < 0.001), the rates of response (100%) and remission (85.0%) were significantly higher (P < 0.001), and relapse rate was lower (P = 0.017) in PCCT group during the 1‐year follow‐up. In addition, the GAF score was significantly higher in the PCCT group than in the other two groups (P < 0.001). Our preliminary data suggest that PCCT is a more efficacious psychotherapy for OCD patients than pharmacotherapy or PCBT.
A novel DrosophilaSOD2 mutant demonstrates a role for mitochondrial ROS in neurodevelopment and disease
Authors: Celotto Alicia M. , Liu Zhaohui , VanDemark Andrew P. , Palladino Michael J. 
Published: June 2012

AbstractReactive oxygen species (ROS) play essential roles in cell signaling, survival, and homeostasis. Aberrant ROS lead to disease and contribute to the aging process. Numerous enzymes and vigilant antioxidant pathways are required to regulate ROS for normal cellular health. Mitochondria are a major source of ROS, and mechanisms to prevent elevated ROS during oxidative phosphorylation require super oxide dismutase (SOD) activity. SOD2, also known as MnSOD, is targeted to mitochondria and is instrumental in regulating ROS by conversion of superoxides to hydrogen peroxide, which is further broken down into H2O and oxygen. Here, we describe the identification of a novel mutation within the mitochondrial SOD2 enzyme in Drosophila that results in adults with an extremely shortened life span, sensitivity to hyperoxia, and neuropathology. Additional studies demonstrate that this novel mutant, SOD2bewildered, exhibits abnormal brain morphology, suggesting a critical role for this protein in neurodevelopment. We investigated the basis of this neurodevelopmental defect and discovered an increase in aberrant axonal that could underlie the aberrant neurodevelopment and brain morphology defects. This novel allele, SOD2bewildered, provides a unique opportunity to study the effects of increased mitochondrial ROS on neural development, axonal targeting, and neural cell degeneration in vivo.
Molecular Understanding of Enyne Hydrogenation over Palladium and Copper Catalysts
Authors: Bridier Blaise , Karhánek David , Pérez‐Ramírez Javier , López Núria 
Published: June 2012

AbstractPartial hydrogenation of unsaturated hydrocarbons comprises an important family of reactions that are applied in many industrial sectors. Understanding the hydrogenation of polyunsatured and polyunsaturated compounds on heterogeneous catalysts at its molecular level remains a challenging milestone to fine‐tune the product distribution. Our study presents a detailed mechanistic analysis of the gas phase hydrogenation of vinylacetylene (1‐butene‐3‐yne) and valylene (2‐methyl‐1‐butene‐3‐yne) over palladium and copper catalysts. These two metals are selected owing to their pronounced differences in continuous flow catalytic tests at ambient pressure. The chemoselectivity, regioselectivity, isomerization, and oligomerization patterns measured in a broad range of feed hydrogen/hydrocarbon ratios are rationalized by density functional theory simulations. An extended Brønsted–Evans–Polanyi relationship for both substrates and active metals is found for the hydrogenation processes. The identified factors that govern selectivity are similar to those identified for smaller C2 and C3 compounds and, thus, a means of systematization to other polyunsaturated compounds is opened up.
High‐Surface‐Area SiO2–ZrO2 Mixed Oxides as Catalysts for the Friedel–Crafts‐Type Alkylation of Arenes with Alcohols and Tandem Cyclopropanation Reactions
Authors: Kaper Helena , Bouchmella Karim , Mutin P. Hubert , Goettmann Frédéric 
Published: July 2012

AbstractThe catalytic activity of SiO2–ZrO2 mixed oxides was studied for the Friedel–Crafts‐alkylation reaction between anisole and benzylic or allylic alcohols. In particular, the influence of Zr content on the catalytic activity was studied. The catalyst with the lowest Zr content (5 mol % ZrO2) showed the highest activity with high selectivity for the alkylated product and good recyclability. We used this catalyst in the reaction of 1‐phenyl‐1‐ethanol with toluene and xylene. We also studied the possibility of a tandem process that involved a Friedel–Crafts alkylation and the subsequent trans‐hydrogenation of trans‐1,3‐diphenyl‐2‐propen‐1‐ol for the synthesis of substituted cyclopropanes.
Microfluidic Solvent Extraction of Metal Ions and Complexes from Leach Solutions Containing Nanoparticles
Authors: Priest C. , Zhou J. , Klink S. , Sedev R. , Ralston J. 
Published: June 2012

AbstractSolvent extraction is often hindered by the presence of particles and surfactants that increase the stability of emulsion phases, i.e., crud, thus preventing full recovery of the organic phase and the valuable metal species. It is shown that bypassing the formation of a particle‐stabilized crud using a stream‐based microfluidic extraction approach has great potential for handling these more challenging and industry‐relevant systems provided sufficient throughputs can be realized. Metal ions and complexes are extracted from copper oxide and chromite leach solutions at high efficiencies and extraction rates within the confinement of a microchannel and in the presence of silica nanoparticles. These findings and their implications for process intensification are discussed.
Chemical Looping Dry Reforming as Novel, Intensified Process for CO2 Activation
Authors: Bhavsar S. , Najera M. , Veser G. 
Published: June 2012

AbstractChemical looping dry reforming (CLDR) is a novel, intensified route for CO2 activation. Two nanostructured carriers (Fe‐BHA and Fe@SiO2) are synthesized, characterized, and evaluated with regard to activity and stability in thermogravimetric and fixed‐bed CLDR reactor studies over a temperature range of ~500–800 °C. Fe‐barium hexaaluminate (Fe‐BHA) shows fast redox kinetics and stable operation over multiple CLDR cycles, while Fe@SiO2 exhibits poor activity for CO generation due to a partial loss of the core‐shell structure and formation of silicates. While the latter could be removed via a two‐step oxidation scheme, carrier utilization remained well below that of Fe‐BHA (~ 51 % versus ~ 15 %). However, the two‐step oxidation configuration turns the net endothermic CLDR process into a net exothermic process, opening up a highly efficient autothermal process alternative.
Dispersion Characteristics and Mass Transfer in a Pilot‐Scale Gas‐Liquid Oscillatory‐Plate Column
Authors: Gomaa H. G. , Hashem N. , Al‐Taweel A. M. 
Published: June 2012

AbstractMass transfer and hydrodynamic characteristics of an oscillatory‐plate column (OPC) and their relation to energy dissipation were investigated using a 0.1‐m diameter pilot‐scale unit. The column is characterized by having plates with a small hole diameter (1.6–3.2 mm) oscillating at 180° out of phase at higher frequencies (0–30 Hz) and small amplitudes (0–3.2 mm). Using this design, it was possible to achieve gas holdup and specific interfacial areas as high as ∼0.8 and 400 m–1, respectively. The maximum gas superficial velocity achieved reaches as high as 1.7 m/s, while the axial dispersion coefficient ranged from ∼10–4 to over ∼3 × 10–3 m2s–1, which is almost one order of magnitude lower than that in bubble columns under similar flow rates. The value of gas velocity of ∼0.1 m s–1 seems to mark a transition beyond which interfacial area, holdup, and axial mixing become practically unchanged. Keeping in view its performance characteristics, the column can satisfactorily meet many of the demands posed by intensified wastewater treatment processes, namely high rates of oxygen transfer, multistage operational mode, uniform distribution of small‐scale turbulence structure, and the ability to handle sludge with relatively high concentrations of suspended solids.
Design of a Pervaporation Photocatalytic Reactor for Process Intensification
Authors: Camera‐Roda G. , Santarelli F. 
Published: June 2012

AbstractThe process intensification obtainable in an integrated photocatalysis‐pervaporation process can be significant, but it depends largely on the correct design of the system. Starting from the kinetic analysis of the photocatalytic reaction, the dimensions and the operative conditions of the photoreactor must be chosen to effectively utilize the radiant energy and the volume of the reactor. Then, the effects of the parameters pertinent to the integrated process are studied and discussed to ascertain the optimum values that enhance the yields in the photocatalytic synthesis of a chemical compound.
Micromixing Characteristics in a Small‐Scale Spinning Disk Reactor
Authors: Boodhoo K. V. K. , Al‐Hengari S. R. 
Published: June 2012

AbstractThin films formed under high acceleration fields in a spinning disk reactor (SDR) are characterized by high shear rates and intense surface ripples which are known to play an important role in improving the selectivity, yield, and final product quality in many mixing‐dependent processes. The micromixing efficiency of a small‐scale SDR of 10 cm disk diameter for a range of hydrodynamic conditions by means of the iodide‐iodate test reaction is determined. Under optimized conditions, the SDR exhibits a better micromixing performance than the mechanically stirred vessel and other continuous intensified reactors, such as the rotating packed bed, when processing water‐like fluids at the highest investigated flow rate of 5 mL s–1. These results highlight the potential of the SDR as an alternative intensified mixer/reactor for processes where a high degree of mixing is desirable.
Process Intensification in Stirred Tanks
Authors: Wu J. , Nguyen B. , Lane G. , Wang S. , Parthasarathy R. , Graham L. J. 
Published: June 2012

AbstractA summary of methods for process intensification in stirred reactors is presented, based mainly on the experience from R&D in the minerals processing industry. The process intensification concept is broadened to include innovations which lead to dramatically increased throughput for large‐scale processing reactors, in contrast to the traditional definition of reactor size reduction, which has so far been ignored by the minerals industry. Methods enabling operating at high solids concentrations in processing tanks are reviewed to increase the throughput. It is proposed that the agitation power constraint at a high solids loading can be overcome by removal of baffles, for slowly reacting slurry systems typical in minerals processing. It is also suggested that the difficulty of pumping of high‐concentration slurry feed can be overcome by operating with stratification, such that the solids residence time is made longer than the bulk flow residence time. Production loss through tank downtime is common in the mineral process industry, thus, a need to reduce the tank downtime should not be underestimated in the context of process intensification. Methods including the swirl flow technology developed by CSIRO and Queensland Alumina Ltd in Australia to suppress the scaling growth, and agitator design principles to reduce erosion are introduced. Enhanced mass transfer toward process intensification is also discussed.
Multiscale Aspects of Modeling Gas‐Phase Nanoparticle Synthesis
Authors: Buesser B. , Gröhn A. J. 
Published: June 2012

AbstractAerosol reactors are utilized to manufacture nanoparticles in industrially relevant quantities. The development, understanding, and scale‐up of aerosol reactors can be facilitated with models and computer simulations. An overview of recent developments of models and simulations is presented and their interconnection in a multiscale approach is discussed. A short introduction of the various aerosol reactor types and gas‐phase particle dynamics is provided as a background for the later discussion of the models and simulations. Models are presented with decreasing time and length scales in sections on continuum, mesoscale, molecular dynamics, and quantum mechanics models.
Rapid Production of Biodiesel in Mesoscale Oscillatory Baffled Reactors
Authors: Phan A. N. , Harvey A. P. , Eze V. 
Published: June 2012

AbstractContinuous alkali‐catalyzed transesterification of rapeseed oil with methanol was carried out in three mesoreactor designs. The induction time decreased with oscillatory Reynolds number for all three reactors. Stable steady states were achieved within induction times of 1.5, 2.5, and 4.0 residence times for the integral, wire wool, and helical baffle designs, respectively. Both experimental and simulated results indicated that under the given conditions there is an optimal residence time for homogeneous transesterification. Higher residence times resulted in reduced fatty acid methyl ester content due to the saponification side reaction. The results demonstrate that biodiesel can be produced at an industrially acceptable level of conversion (> 95 %) in < 5 min residence time. This requires a combination of high catalyst concentration and good mixing.
Process Intensification of Emulsion Polymerization Using a Compartment Reactor
Authors: Ohmura N. , Horie T. , Kumagai N. , Esaki T. , Yamazaki T. 
Published: June 2012

AbstractAttempts were made to intensify continuous emulsion polymerization using a compartment reactor consisting of three well‐mixing compartments. The goal of this intensification is to obtain a stable and monodisperse particle size as well as high monomer conversion, by controlling the mixing under continuous operation. A two‐bladed paddle impeller was used in the first compartment to intensify the dispersibility and reactivity in the aqueous phase, while a rotating disk was used in the third compartment to avoid excessive flocculation of the polymer particles. In the second compartment, a two‐bladed turbine impeller or a rotating disk was used. The compartment reactor successfully obtained much higher monomer conversion and also more stable and monodisperse particles than a single continuous stirred‐tank reactor. The oscillations of the mean particle size were greatly suppressed by spatially different mixing operations.