bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of serial patient blood gas, electrolyte and glucose results to derive biologic variation: a new tool to assess the acceptability of intensive care unit testing
Authors: Cembrowski George S. , Tran David V. , Higgins Trefor N.
Published: August 2010

Background: Most estimates of biologic variation (sb) are based on periodically acquiring and storing specimens, followed by analysis within a single analytic run. We demonstrate for many intensive care unit (ICU) tests, only patient results need be statistically analyzed to provide reliable estimates of sb.

Methods: Over 11 months, approximately 28,000 blood gas measurements (including electrolyte panels and glucose) were performed on one of two Radiometer ABL800 FLEX analyzers (Radiometer, Copenhagen, Denmark) from 1676 ICU patients. We tabulated the measurements of paired intra-patient blood samples drawn within 24 h of each other. After removal of outliers, we calculated the standard deviations of duplicates (SDD) of the intra-patient pairs grouped in 2-h intervals: 0–2 h, 2–4 h, 4–6 h, … 20–22 h and 22–24 h. The SDDs were then regressed against the time intervals of 2–14 h; extrapolation to zero time represents the sum of sb and short-term analytic variation (sa).

Results: Substitution of experimentally derived analytic error permitted the calculation of coefficient of variation (biologic) (CVb) (100 sb/mean): pH, 0.3%; pCO2, 5.7%; pO2, 13%; Na+, 0.6%; K+, 4.8%; Cl–, 0.8%; HCO3
–, 3.2%; iCa++, 2.4%; and glucose, 10.3%. The CVb of the electrolytes very closely matches the lowest estimates obtained in the usual manner.

Conclusions: Derivation of the ratio of biologic to analytic variation indicates that the ABL800 is extremely suitable for ICU testing. This analysis should be extended to other point of care instrument systems.

Clin Chem Lab Med 2010;48:1447–54.
Reward Changes Salience in Human Vision via the Anterior Cingulate
Authors: Hickey Clayton , Chelazzi Leonardo , Theeuwes Jan
Published: August 2010

Reward-related mesolimbic dopamine steers animal behavior, creating automatic approach toward reward-associated objects and avoidance of objects unlikely to be beneficial. Theories of dopamine suggest that this reflects underlying biases in perception and attention, with reward enhancing the representation of reward-associated stimuli such that attention is more likely to be deployed to the location of these objects. Using measures of behavior and brain electricity in male and female humans, we demonstrate this to be the case. Sensory and perceptual processing of reward-associated visual features is facilitated such that attention is deployed to objects characterized by these features in subsequent experimental trials. This is the case even when participants know that a strategic decision to attend to reward-associated features will be counterproductive and result in suboptimal performance. Other results show that the magnitude of visual bias created by reward is predicted by the response to reward feedback in anterior cingulate cortex, an area with strong connections to dopaminergic structures in the midbrain. These results demonstrate that reward has an impact on vision that is independent of its role in the strategic establishment of endogenous attention. We suggest that reward acts to change visual salience and thus plays an important and undervalued role in attentional control.
Impaired Speech Repetition and Left Parietal Lobe Damage
Authors: Fridriksson Julius , Kjartansson Olafur , Morgan Paul S. , Hjaltason Haukur , Magnusdottir Sigridur , Bonilha Leonardo , Rorden Christopher
Published: August 2010

Patients with left hemisphere damage and concomitant aphasia usually have difficulty repeating others' speech. Although impaired speech repetition, the primary symptom of conduction aphasia, has been associated with involvement of the left arcuate fasciculus, its specific lesion correlate remains elusive. This research examined speech repetition among 45 stroke patients who underwent aphasia testing and MRI examination. Based on lesion–behavior mapping, the primary structural damage most closely associated with impaired speech repetition was found in the posterior portion of the left arcuate fasciculus. However, perfusion-weighted MRI revealed that tissue dysfunction, in the form of either frank damage or hypoperfusion, to the left inferior parietal lobe, rather than the underlying white matter, was associated with impaired speech repetition. This latter result suggests that integrity of the left inferior parietal lobe is important for speech repetition and, as importantly, highlights the importance of examining cerebral perfusion for the purpose of lesion–behavior mapping in acute stroke.
Intrinsic Circuit Organization and Theta–Gamma Oscillation Dynamics in the Entorhinal Cortex of the Rat
Authors: Quilichini Pascale , Sirota Anton , Buzsáki György
Published: August 2010

A thorough knowledge of the intrinsic circuit properties of the entorhinal cortex (EC) and the temporal dynamics these circuits support is essential for understanding how information is exchanged between the hippocampus and neocortex. Using intracellular and extracellular recordings in the anesthetized rat and anatomical reconstruction of single cells, we found that EC5 and EC2 principal neurons form large axonal networks mainly within their layers, interconnected by the more vertically organized axon trees of EC3 pyramidal cells. Principal cells showed layer-specific unique membrane properties and contributed differentially to theta and gamma oscillations. EC2 principal cells were most strongly phase modulated by EC theta. The multiple gamma oscillators, present in the various EC layers, were temporally coordinated by the phase of theta waves. Putative interneurons in all EC layers fired relatively synchronously within the theta cycle, coinciding with the maximum power of gamma oscillation. The special wiring architecture and unique membrane properties of EC neurons may underlie their behaviorally distinct firing patterns in the waking animal.
Structural Dynamics of Synapsesin VivoCorrelate with Functional Changes during Experience-Dependent Plasticity in Visual Cortex
Authors: Tropea Daniela , Majewska Ania K. , Garcia Rodrigo , Sur Mriganka
Published: August 2010

The impact of activity on neuronal circuitry is complex, involving both functional and structural changes whose interaction is largely unknown. We have used optical imaging of mouse visual cortex responses and two-photon imaging of superficial layer spines on layer 5 neurons to monitor network function and synaptic structural dynamics in the mouse visual cortexin vivo. Total lack of vision due to dark-rearing from birth dampens visual responses and shifts spine dynamics and morphologies toward an immature state. The effects of vision after dark rearing are strongly dependent on the timing of exposure: over a period of days, functional and structural changes are temporally related such that light stabilizes spines while increasing visually driven activity. The effects of long-term light exposure can be partially mimicked by experimentally enhancing inhibitory signaling in the darkness. Brief light exposure, however, results in a rapid, transient, NMDA-dependent increase of cortical responses, accompanied by increased dynamics of dendritic spines. These findings indicate that visual experience induces rapid reorganization of cortical circuitry followed by a period of stabilization, and demonstrate a close relationship between dynamic changes at single synapses and cortical network function.
A Noncompetitive BACE1 Inhibitor TAK-070 Ameliorates Aβ Pathology and Behavioral Deficits in a Mouse Model of Alzheimer's Disease
Authors: Fukumoto Hiroaki , Takahashi Hideki , Tarui Naoki , Matsui Junji , Tomita Taisuke , Hirode Mitsuhiro , Sagayama Masumi , Maeda Ryouta , Kawamoto Makiko , Hirai Kazuko , Terauchi Jun , Sakura Yasufumi , Kakihana Mitsuru , Kato Kaneyoshi , Iwatsubo Takeshi , Miyamoto Masaomi
Published: August 2010

We discovered a nonpeptidic compound, TAK-070, that inhibited BACE1, a rate-limiting protease for the generation of Aβ peptides that are considered causative for Alzheimer's disease (AD), in a noncompetitive manner. TAK-070 bound to full-length BACE1, but not to truncated BACE1 lacking the transmembrane domain. Short-term oral administration of TAK-070 decreased the brain levels of soluble Aβ, increased that of neurotrophic sAPPα by ∼20%, and normalized the behavioral impairments in cognitive tests in Tg2576 mice, an APP transgenic mouse model of AD. Six-month chronic treatment decreased cerebral Aβ deposition by ∼60%, preserving the pharmacological efficacy on soluble Aβ and sAPPα levels. These results support the feasibility of BACE1 inhibition with a noncompetitive inhibitor as disease-modifying as well as symptomatic therapy for AD.
Presynaptic Kainate Receptor Activation Preserves Asynchronous GABA Release Despite the Reduction in Synchronous Release from Hippocampal Cholecystokinin Interneurons
Authors: Daw Michael I. , Pelkey Kenneth A. , Chittajallu Ramesh , McBain Chris J.
Published: August 2010

Inhibitory synaptic transmission in the hippocampus in mediated by a wide variety of different interneuron classes which are assumed to play different roles in network activity. Activation of presynaptic kainate receptors (KARs) has been shown to reduce inhibitory transmission but the interneuron class(es) at which they act is only recently beginning to emerge. Using paired recordings we show that KAR activation causes a decrease in presynaptic release from cholecystokinin (CCK)- but not parvalbumin-containing interneurons and that this decrease is observed when pyramidal cells, but not interneurons, are the postsynaptic target. We also show that although the synchronous release component is reduced, the barrage of asynchronous GABA release from CCK interneurons during sustained firing is unaffected by KAR activation. This indicates that presynaptic KARs preserve and act in concert with asynchronous release to switch CCK interneurons from a phasic inhibition mode to produce prolonged inhibition during periods of intense activity.
The effect of systemic and ovarian infusion of glucose, galactose and fructose on ovarian function in sheep
Authors: Campbell B K , Kendall N R , Onions V , Scaramuzzi R J
Published: August 2010

Glucose is a critical metabolic fuel in most mammals although many foodstuffs also contain high levels of the monosaccharides, galactose and fructose. The aims of this work were to determine the insulin response to challenges of these sugars (experiment 1) and to examine the effect of systemic (experiment 2) and direct ovarian (experiment 3) infusion of these monosaccharides on ovarian function in ewes with autotransplanted ovaries. In experiment 1, both fructose (fourfold increase peaking in 2 h) and galactose (twofold increase; 30 min) elicited markedly different (P<0.001) insulin responses than glucose (sevenfold increase; 20 min) although the total amount released following fructose and glucose challenge was similar. In experiment 2, low-dose systemic fructose infusion had no acute effect on insulin but did depress FSH (P<0.05), and following the end of fructose infusion, a transient increase in FSH and insulin was observed (P<0.05), which was associated with an increase (P<0.05) in ovarian oestradiol and androstenedione secretion. Systemic infusion of neither glucose nor galactose had a significant effect on ovarian steroidogenesis although glucose acutely suppressed insulin levels. In contrast, ovarian arterial infusion of fructose and glucose had no effect on ovarian function whereas galactose suppressed ovarian follicle number and steroid secretion (P<0.05). In conclusion, this work indicates that fructose and galactose can influence ovarian functionin vivoin sheep and that different mechanisms are involved. Thus, fructose exerts stimulatory effects through indirect modulation of peripheral insulin and/or gonadotrophin levels whereas galactose exerts primarily suppressive effects by direct actions on the ovary.
Effects of Barrier Width on Spectral Response of Strained Layer Superlattices for High Efficiency Solar Cells
Authors: Bradshaw Geoffrey K. , Carlin Conrad Zachary , Colter Peter C. , Harmon Jeffrey L. , Samberg Joshua P. , Bedair Salah M.
Published: August 2010

Characteristics of strained layer superlattices (SLS) consisting of alternating layers InxGa1-xAs and GaAs1-yPy are examined for use in high efficiency solar cells. The effects of SLS quantum barrier widths on tunneling probability and short circuit current are discussed through analysis of J-V and spectral response measurements. Results indicate a threshold barrier thickness for which tunneling effects are deleterious. Effect of the number of SLS periods incorporated into a p-i-n structure and maximum number of periods are presented through spectral response and CV analysis. It is demonstrated that SLS show increasing responsivity with increasing number of periods due to higher absorption. CV analysis is performed to determine zero bias depletion widths for verifying appropriate number of SLS periods and fully depleted SLS region.
GaAs Based InAs/InGaAs Quantum Dots-in-a-Well Solar Cells and Their Concentration Applications
Authors: Yang Kai , El-Emawy Mohamed A , Gu Tingyi , Stintz Andreas , Lester Luke F
Published: August 2010

Quantum dot (QD) solar cells have been actively investigated recently since they have been theoretically shown to have the potential to realize high conversion efficiencies. However, very little research has analyzed the effect the dots have on the transport or recombination effects in the device. In this paper, we report the I-V and spectral response characteristics of InAs/InGaAs “dots-in-a-well” (DWELL) solar cells and compared them with GaAs control cells. The QD cells show higher short circuit density (Jsc) and better long-wavelength efficiency compared to the control cell. By comparing the dark current behavior of the QD cells to the GaAs control cells, we have conservatively estimated the concentration level at which the QD solar cells would surpass GaAs control devices.

The quantum dot solar cells are grown by molecular beam epitaxy using the DWELL technique and a standard pin structure. The control cell structure is similar to the QD one except that there are no InAs dots or surrounding InGaAs quantum wells. The light I-V characteristics were measured under AM1.5G at 100 mW/cm2 illumination. The control cell has a Voc of 0.89V and a Jsc of 9.1 mA/cm2. The InAs QD solar cell has a Voc of 0.68 V and a Jsc of 12.2 mA/cm2. The QD cell has about a 33% larger short circuit current density compared to the GaAs control cell, which is mainly due to the higher photon absorption rate related to the DWELL structure. The spectrum response data show that the GaAs control cell and the QD cell have similar external quantum efficiency (EQE) in the visible to near-IR range (400-870nm). Beyond the GaAs absorption edge (870nm), the QD solar cell shows extended response with much higher measured EQE up to ˜1200 nm. This is strong evidence of the contribution from the InAs QDs and InGaAs QWs, the latter being the primary contributor to the increased Jsc.

We calculated the “local” ideality factor from measured dark IV data, and then substituted it into a single diode equation to get the “local” reverse saturation current. Whereas the GaAs control shows the typical monotonically decreasing ideality from 0.3 to 0.8V, a linearly increasing ideality is observed in the QD cell. Based on the measured dark currents, and neglecting series resistance, we extrapolated the IV curves to higher voltages and found that they intercept at ˜2×104 mA/cm2. Dividing the intercept point Jdark by the Jsc of the QD cell conservatively estimates the light concentration (˜1400×) above which the QD cell would have a higher Voc than the GaAs cell assuming additivity applies. This result is mainly attributed to the unique carrier transport properties that are introduced into the solar cell devices that utilize QDs.
Inorganic Photo-sensitized Transparent Conductive Oxide (TCO) Nanocomposite Thin Films for Photovoltaic (PV) Energy Conversion
Authors: Allen Cary G. , Shih Grace H. , Potter B.G.
Published: August 2010

Nanophase semiconductor composites are widely researched for the development of third-generation photovoltaic (PV) devices. Through quantum-size effects and phase assembly manipulation the optical absorption and carrier transport properties of nanocomposite films can be influenced. We investigate the potential for improved PV-relevant material performance by examining the photo-sensitization of indium-tin-oxide (ITO) with nanophase germanium (Ge). Nanocomposite films are produced by a sequential, RF-magnetron sputter deposition technique. Deposition control and post-deposition annealing are used to demonstrate the manipulation of the extended-assembly of the nanocrystalline Ge phase. Optical absorption characteristics were correlated to variations in the composite film structure as confirmed by transmission electron microscopy. In addition to structure-dependent variation in spectral absorption, spectrally resolved photoconductivity measurements demonstrate enhanced photoconductivity of composite films associated with the incorporation of the Ge phase into the ITO host. These results support the further evaluation of such nanocomposite TCO materials in optoelectronic devices, including PV systems.
Photovoltaic Properties of Polyaniline-Titania Composite for Hybrid Solar Cells Applications
Authors: Ibrahim Michael Ibrahim , Bassil Maria Joseph , Demirci Umit B. , El Hajj Moussa Georges , Salles Vincent , El Tahchi Mario Remond , Miele Philippe
Published: August 2010

Solar energy harvesting has been extensively studied in the last three decades to provide a green energy source. Hybrid photovoltaics (HPV) based on titania (TiO2) are researched for their easiness of production and low cost. Nanostructured mesoporous titania films and conductive polymers were used recently to form hybrid solar cells [1]. TiO2, mainly an n-type semiconductor with a band gap of 4.2 eV, is employed in several applications from which paints form the highest world use of titania making it an attractive material to use in HPV industry. On the other side, our targeted conductive polymer is polyaniline (PANI), a hole conductor polymer, which is used in such HPV cells due to its high charge-carriers mobility, absorption coefficient in the visible range and environmental stability. PANI and nanocrystalline TiO2 films fabricated using spin coating or layer by layer assembly techniques behave as a p-n heterojunction diode and can be used as solar cells [2-4].

Precursor solutions are prepared by polymerizing aniline-HCl inside an aqueous solution of titania. To study the effect of the precursor concentration on the PANI-TiO2 composite, polymerization of aniline is held in diverse TiO2 concentrations in water. Industrial grade TiO2 powders with particle size ranging from 200 nm to several μm are used. PANI-TiO2 precursor solutions are dip coated or slot dyed on various substrates such as PMMA, PET and PP, all with metal oxide conductive coatings. Bulk PANI-TiO2 pellets are prepared for comparison. The electrical and photovoltaic properties of the obtained films and pellets are investigated to choose the optimum blend composition for HPV cell. Finally a theoretical study and an analytical model of the HPV cell are presented relating the size of TiO2 and PANI particles and their respective geometrical distribution inside the blend to the transport characteristics of charge carriers and the overall efficiency of the HPV cell.[1] M. McGehee, MRS Bulletin, Vol. 34, No. 2, February 2009.[2] Z. Liu, W. Guo, D. Fu and W. Chen, Synthetic Metals, Vol. 156, pp. 414–416, 2006.[3] Z. Liu, J. Zhou, H. Xue, L. Shen, H. Zang and W. Chen, Synthetic Metals, Vol. 156, pp. 721–723, 2006.[4] X. Zhang, G. Yan, H. Ding and Y. Shan, Materials Chemistry and Physics, Vol. 102, pp. 249–254, 2007.
First Principles Calculations of Complex Intermediate Band Materials for Photovoltaic Devices
Authors: Wahnón Perla , Aguilera Irene , Palacios Pablo , Sánchez Kefren
Published: August 2010

An ab initio study of several compounds candidates to behave as intermediate band materials is presented. The use of these materials as the active element in solar cells is a promising way to enhance the photovoltaic efficiency. Indeed from this point of view, most interesting compounds are those whose host semiconductor presents a band-gap close to the optimum value of 2 eV. Chalcogenide compounds substituted by light transition metals are solid candidates to this end. While they are being further characterized and experimentally synthesized, another approach is being examined. It consists of using Si as host semiconductor. Ti implantation at concentrations several orders of magnitude above equilibrium solubility has shown a probable intermediate band material behavior, the origin of the intermediate band being related to levels of interstitial Ti. Optoelectronic characterization of this material is completed. A novel possibility consists of combining chalcogen S implantation with boron. In this case preliminary results of electronic structure are shown.
Enhanced Efficiency Dye Sensitized Solar Cells Through Acid Pre-treatment
Authors: Watson Trystan , Bryant Daniel , Worsley David
Published: August 2010

A nitric acid (2M) pre-treatment is shown to increase the efficiency of a standard dye sensitized solar cell mounted on a FTO glass substrate from 4.15% to 5.12%. The pre-treatment involves immersing an FTO glass electrode coated with commercial ethyl cellulose based TiO2 paste for 1-60 minutes prior to sintering at 450°C. The pre-treatment leads to agglomeration of the TiO2 creating a scattering layer which covers the acid treated surface on short term immersion (<30 mins) and penetrates the bulk layer upon long immersion. The scattering layer itself takes up less of the sensitizing (N719) dye but scatters photons in the rest of the film. The optimum immersion time under room temperature conditions was found to be ca 20 minutes since at much longer immersion times the bulk film particle agglomeration reduced efficiency. The choice of anion in the acid is critical with certain species, notably phosphate, resulting in blockage of dye absorption sites in the entire film resulting in reduced cell efficiency.
Impedance spectroscopy study of solid-state dye-sensitized solar cells with varying Spiro-OMeTAD concentration
Authors: Góes Márcio S , Fabregat-Santiago Francisco , Bueno Paulo R , Bisquert Juan
Published: August 2010

This work reports on the changes of solid-state cells dye-sensitized solar cells performance with the variation of concentration of spiro-OMeTAD between 5% and 25% in the fabrication of the cell. The changes in charge recombination and capacitance correlate with the improvement of current-potential characteristics a increasing spiro-OMeTAD content, which is explained by reduction of transport resistance for hole transport, the increase of charge separation in the dye molecules, and importantly, with the increase of the β-factor in the recombination resistance, that causes a reduction of the diode ideality factor.
The Use of Near Infra Red as a Rapid Heat Treatment Process in the Manufacture of Metal-based Dye-sensitized Solar Cells
Authors: Watson Trystan , Mabbett Ian , Worsley David
Published: August 2010

A near infrared heating method is presented which directly heats metal substrates to very high temperatures within seconds. The technique is used to heat 1mm thick titanium and stainless steel metal coupons onto which 1 cm2commercial TiO2pastes have been deposited within 12-25 seconds giving assembled dye sensitized solar cell efficiencies which are equivalent to cells prepared using a convection oven for 1800 seconds. The near infrared method is applicable to different paste thicknesses and paste types as well as different metal substrates. Near infrared sintering for the shortest times 12.5 seconds yielded cells with the highest efficiency compared to convection oven prepared samples. This ultrafast heating seems to drive off binder very effectively and lead to rapid sintering. Ultrafast sintering allows peak metal temperatures of 500-800 °C to be achieved without the massive losses in cell efficiency observed with the conventional heat treatment at temperatures over 600 ◦C.
High Performance Quasi-Solid Dye-Sensitized Solar Cells with Nano Clay Electrolyte
Authors: Inoue Tomoyuki , Uchida Satoshi , Kubo Takaya , Segawa Hiroshi
Published: August 2010

The artificial nano-clay powder was newly examined as a gelator of electrolyte of quasi-solid-state dye-sensitized solar cell (DSSC). The size of clay has two main distributions with 1.4 nm and 20 nm in diameter which are confirmed by STEM observation. The gelation point was determined by using Rheometer. The gel state maintained with more than 5wt% nano-clay in the acetonitrile based solvent. The quasi-solid-state DSSC with nano-clay electrolyte (10 wt%) was successfully showed a high photoelectric conversion efficiency of 10.3%, which is equivalent to that using a liquid electrolyte.
Three Synthesis Routes of Single-crystalline PbS Nanowires and Their Electrical Transport Properties
Authors: Jang So Young , Song Yun Mi , Kim Han Sung , Cho Yong Jae , Seo Young Suk , Jung Gyeong Bok , Lee Chi-Woo , Park Jeunghee
Published: August 2010

Single-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pre-grown CdS NWs. They were uniformly grown with the [100] or [110], [112] direction in a controlled manner. In the solvothermal growth, the oriented attachment of the octylamine (OA) ligands enables the NWs to be produced with a controlled morphology and growth direction. As the concentration of OA increases, the growth direction evolves from the [100] to the higher surface-energy [110] and [112] directions. In the synthesis involving chemical vapor transport and the substitution reaction, the use of a lower growth temperature causes the higher surface-energy growth direction to change from [100] to [110]. We fabricated field effect transistors using single PbS NW, which showed intrinsic p-type semiconductor characteristics for all three routes. For the PbS NW with a thinner oxide layer, the carrier mobility was measured to be as high as 10 cm2V−1s−1.
Chemical Vapor Functionalization of ZnO Nanocrystals
Authors: Ali Moazzam , Donakowski Marty D. , Winterer Markus
Published: August 2010

Chemical Vapor Functionalization (CVF) is a method in which nanocrystals undergo in situ functionalization in the gas phase. In CVF, two reactors are used in series. The first reactor consists of a hot quartz tube (1073 K) where ZnO nanocrystals are synthesized in the gas phase from diethylzinc and oxygen. The second reactor, connected at the exit of the first one and kept at lower temperature (673 K), is used as functionalization chamber. At the connecting point of the two reactors, vapors of organic functionalizing agents are injected which react with the surface of ZnO nanocrystals. ZnO nanocrystals have been functionalized by 1-hexanol, n-hexanoic acid, n-hexanal and 1-hexylamine. Functionalized ZnO nanocrystals have been characterized by Dynamic Light Scattering, X-ray Diffraction and Diffuse Reflectance Infrared Fourier Transform Spectroscopy.
Precipitation of Mixed-Alkali Molybdates During HLW Vitrification
Authors: Kroeker Scott , Higman Carolyn , Michaelis Vladimir K , Svenda Nicholas B , Schuller Sophie
Published: August 2010

Crystalline precipitates from molybdenum-containing nuclear waste glasses are complex, often containing multiple cations which confound routine structural techniques. A simplified mixed-alkali borosilicate model glass was found to have minor crystalline phases which could not be identified by x-ray diffraction. Multinuclear magnetic resonance (NMR) spectroscopy revealed sharp peaks characteristic of crystallinity superimposed on the broader glass signals, but were unattributable to any known molybdate phases. When a comprehensive range of cesium molybdates failed to reveal any matches with the observed 133Cs magic-angle spinning (MAS) NMR peaks in the composite glass/crystalline material, a series of mixed-alkali sodium-cesium molybdate phases was synthesized. 23Na, 133Cs and 95Mo MAS NMR revealed the formation of two mixed-cation molybdates which correlate with the observed NMR peaks for the phase-separated model glass. This work highlights the prominence of multiple crystalline phases in Mo-bearing nuclear waste glasses, and demonstrates the unique utility of solid-state NMR as a fingerprinting approach to identifying complex phases, especially where x-ray diffraction is limited by multiple phases, low concentrations or substitutionally disordered precipitates.
Defects and Recombination Kinetics in Copper Indium Gallium Sulfide Thin Films With Spatially Resolved Luminescence in the μm-scale
Authors: Heidemann Florian , Bauer Gottfried H.
Published: August 2010

Chalcopyrite Cu(In,Ga)S2 is a promising absorber in thin film solar cells, although the comparable high band gaps so far do not correspond to equivalent high open circuit voltages. We have performed photoluminescence studies on CdS passivated absorber layers deposited on Mo coated soda lime glass. From spectrally and spatially resolved (≤ 1μm) room temperature photoluminescence measurements we have extracted the local splitting of quasi- Fermi levels (EFn-EFp) and local absorption (A(ω)) particularly in the sub bandgap-regime via Planck's generalized law. We observe a substantial negative correlation coefficient between the local sub bandgap/defect absorption and the local (EFn-EFp), which we interpret in terms of the recombination of photogenerated minority carriers (here electrons) via sub bandgap states/deep defects. Moreover we have correlated local PL yields with corresponding values at neighbor sites versus distance (increment analysis). As we find lateral correlation distances in the vicinity of average grain sizes we conclude grains with PL yield and according different splitting of (EFn-EFp) to be independent from one another and be laterally distributed randomly.
Growth process and crystallographic properties of ammonia-induced vaterite
Authors: Hu Qiaona , Zhang Jiaming , Becker Udo
Published: August 2010

Metastable vaterite crystals were produced by increasing the pH of Ca2+- and CO32--containing solutions through diffusing ammonia gas. The SEM and TEM studies indicate that this ammonia-induced vaterite is polycrystalline with a 6-fold symmetry of the crystal aggregate. The morphology and crystallographic properties of this assemblage change druing crystallization. One hour after nucleation starts, vaterite grains display a spherical structure composed of nano-particles (5-10 nm) with random crystallographic orientations. After that, horizontal layers begin to develop at the edge of the sphere and gradually tilt toward the center as they grow vertically, which results in a three-dimensional morphology with a dent in the center. The vaterite grains mature fully 16 hours after nucleation. TEM analysis indicates the grown vaterite grain (50-60 μm) consists of numerous hexagonal pieces of single crystals (1-2 μm) of similar crystallographic orientations. High-resolution TEM demonstrates that these single crystals grow along (001) with {110} hexagonal boundaries.
Synthesis and Characterization of Carbon Nanotube-Nickel/Nickel Oxide Core/shell Nanoparticle Heterostructures Incorporated in Polyvinyl Alcohol Hydrogel
Authors: Shi Wenwu , Crews Kristy , Chopra Nitin
Published: August 2010

Carbon nanotube (CNT)-nickel/nickel oxide (Ni/NiO) core/shell nanoparticles (CNC) heterostructures were prepared in a unique single-step synthetic route by direct chemical precipitation of nanoparticles on CNT surface. Chemical vapor deposition (CVD)-grown CNTs (average diameter ˜42.7±12.3 nm) allowed for direct nucleation and uniform coating of Ni/NiO core/shell nanoparticles (average diameter ˜11.8±1.7 nm). The crystal structure, morphology, and phases in CNC heterostructures were studied using high resolution transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Subsequently, the as-produced CNC heterostructures were incorporated into polyvinyl alcohol (PVA) hydrogel resulting in CNC heterostructure-PVA hydrogel with ˜ 75% water absorbing capability. These novel hydrogels were also characterized by SEM and showed actuation under 0.2 T magnet. They are promising for smart analytical devices and platform.
Influence of treatment in multiple sclerosis dysability: an open, retrospective, non-randomized long-term analysis
Authors: Werneck Lineu Cesar , Lorenzoni Paulo José , Radünz Vitor A , Utiumi Marco A.T , Kay Cláudia Suemi Kamoi , Scola Rosana Herminia
Published: August 2010

The efficacies of immunosuppressive (IMS) and immunomodulatory (IMM) drugs for multiple sclerosis (MS) have been reported in several studies. These agents can reduce relapse rates and lesions observed by magnetic resonance imaging studies. However, the effect of these medications in disability progression over 4 years is rarely examined. OBJECTIVE: To study the disabilities associated with MS patients after a long time period and to analyze the therapeutic influence of different types of treatments in patient disease progression. METHOD: This is an open, uncontrolled, non-randomized, retrospective study of the disease progression using the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS) in 155 cases of MS, which were 76% female with a mean age of onset of 30.21±9.70. The follow-up period was 115.39±88.08 months (median 92, 3 to 447 months). These cases were submitted to the following 277 different therapeutic procedures: 62 without IMS or IMM therapy (SYT) (just corticosteroids), 53 with azathioprine (AZA), 53 interferon-β (IFNβ)-1b 250 µg (BET), 55 IFNβ-1a 22 µg (R22), 19 IFNβ-1a 30 µg (AVO), 15 IFNβ-1a 44 µg (R44), 15 glatiramer acetate (COP) 20 mg, and 5 cases with mitoxantrone (MIT). RESULTS: The median EDSS group was 2.00 (0 to 5.5, mean 1.89±1.52) at the onset of each treatment and 2.50 (0 to 9, mean 3.06±2.18) at the end. The median initial MSSS was 3.34 (0.25 to 9.50, mean 3.94±2.91) and the final medial was 3.90 (0.05 to 9.88, mean 4.02±2.78). The EDSS between initial and final score for the whole group had statistically significant progression, as well as for the sub-groups SYT, AZA, BET and R22. No statistically significance difference was found in the MSSS between initial and final scores in the whole group or treatment sub-groups. The variation between the initial and final EDSS and MSSS among the types of treatments found no statistical significance for any group. CONCLUSION: In this study series, no statistical difference was found in the long-term progression of disability among the IMS and IMM treated cases, nor in the cases treated only with corticosteroids.
Auditory evoked potentials and multiple sclerosis
Authors: Matas Carla Gentile , Matas Sandro Luiz de Andrade , Oliveira Caroline Rondina Salzano de , Gonçalves Isabela Crivellaro
Published: August 2010

Multiple sclerosis (MS) is an inflammatory, demyelinating disease that can affect several areas of the central nervous system. Damage along the auditory pathway can alter its integrity significantly. Therefore, it is important to investigate the auditory pathway, from the brainstem to the cortex, in individuals with MS. OBJECTIVE: The aim of this study was to characterize auditory evoked potentials in adults with MS of the remittent-recurrent type. METHOD: The study comprised 25 individuals with MS, between 25 and 55 years, and 25 age- and gender-matched healthy controls (research and control groups). Subjects underwent audiological and electrophysiological evaluations. RESULTS: Statistically significant differences were observed between the groups regarding the results of the auditory brainstem response and the latency of the Na and P300 waves. CONCLUSION: Individuals with MS present abnormalities in auditory evoked potentials indicating dysfunction of different regions of the central auditory nervous system.
Neuronal damage and memory deficits after seizures are reversed by ascorbic acid?
Authors: Tomé Adriana da Rocha , Feitosa Chistiane Mendes , Freitas Rivelilson Mendes de
Published: August 2010

The objective of the present study was to evaluate the neuroprotective effects of ascorbic acid (AA) in rats, against the neuronal damage and memory deficit caused by seizures. Wistar rats were treated with 0.9% saline (i.p., control group), ascorbic acid (500 mg/kg, i.p., AA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), and the association of ascorbic acid (500 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of ascorbic acid (AA plus pilocarpine group). After the treatments all groups were observed for 24 h. Pilocarpine group presented seizures which progressed to status epilepticus in 75% of the animals. Pretreatment with AA led to a reduction of 50% of this rate. Results showed that pretreatment with AA did not alter reference memory when compared to a control group. In the working memory task, we observed a significant day's effect with important differences between control, pilocarpine and AA plus pilocarpine groups. Pilocarpine and AA plus pilocarpine groups had 81 and 16% of animals with brain injury, respectively. In the hippocampus of pilocarpine animals, it was detected an injury of 60%. As for the animals tested with AA plus pilocarpine, the hippocampal region of the group had a reduction of 43% in hippocampal lesion. Our findings suggest that seizures caused cognitive dysfunction and neuronal damage that might be related, at least in part, to the neurological problems presented by epileptic patients. AA can reverse cognitive dysfunction observed in rats with seizures as well as decrease neuronal injury in rat hippocampus.
Expression of HSP70 in cerebral ischemia and neuroprotetive action of hypothermia and ketoprofen
Authors: Tirapelli Daniela Pretti da Cunha , Carlotti Junior Carlos Gilberto , Leite João Pereira , Tirapelli Luis Fernando , Colli Benedicto Oscar
Published: August 2010

Heat shock proteins (HSPs) are molecular chaperones that bind to other proteins to shepherd them across membranes and direct them to specific locations within a cell. Several injurious stimuli can induce Hsp70 expression, including ischemia. This study aimed to investigate the pattern of expression of protein (immunohistochemistry) and gene (real-time PCR) Hsp70 in experimental focal cerebral ischemia in rats by occlusion of the middle cerebral artery for 1 hour and the role of neuroprotection with hypothermia (H) and ketoprofen (K). The infarct volume was measured using morphometric analysis defined by triphenyl tetrazolium chloride. It was observed increases in the protein (p=0.0001) and gene (p=0.0001) Hsp70 receptor in the ischemic areas that were reduced by H (protein and gene: p<0.05), K (protein: p<0.001), and H+K (protein: p<0.01 and gene: p<0.05). The Hsp70 increases in the ischemic area suggests that the Hsp70-mediated neuroexcitotoxicity plays an important role in cell death and that the neuroprotective effect of both, H and K are directly involved with the Hsp70.
Endoscopic endonasal transsphenoidal approach for pituitary adenomas: technical aspects and report of casuistic
Authors: Santos Américo Rubens Leite dos , Fonseca Neto Roberto Monteiro , Veiga José Carlos Esteves , Viana Jr José , Scaliassi Nilza Maria , Lancellotti Carmen Lúcia Penteado , Lazarini Paulo Roberto
Published: August 2010

OBJECTIVE: Analyse technical aspects, effectiveness and morbidity of the endoscopic endonasal transphenoidal approach for pituitary adenomas. METHOD: From January 2005 to September 2008, 30 consecutive patients underwent endoscopic endonasal resection of pituitary adenomas with a follow up from 3 to 36 months. Their medical charts were retrospectively analysed. RESULTS: There were 18 women and 12 men, mean age 44 years (range 17-65 yr). Among the 30 patients, 23 had macroadenomas and 7 microadenomas. Twelve patients had non-functioning tumors, 9 had ACTH-secreting tumors, 8 had GH-secreting tumors and 1 prolactinoma. Complete resection and hormonal control was achieved in all microadenomas. Macroadenomas were completely removed in 6 patients, subtotal resection in 6 and partial resection in 11. Three patients had diabetes insipidus and 5 had CSF leaks treated with lumbar drainage. CONCLUSION: The endonasal endoscopic approach for pituitary tumors is effective and has low morbidity.
Dural arteriovenous fistulas with direct cortical venous drainage treated with Onyx®: a case series
Authors: Trivelato Felipe Padovani , Abud Daniel Giansante , Ulhôa Alexandre Cordeiro , Menezes Tiago de Jesus , Abud Thiago Giansante , Nakiri Guilherme Seikem , Colli Benedicto Oscar , Gusmão Sebastião Nataniel Silva , Rezende Marco Túlio Salles
Published: August 2010

Dural arteriovenous fistulas (DAVFs) may have aggressive symptoms, especially if there is direct cortical venous drainage. We report our preliminary experience in transarterial embolization of DAVFs with direct cortical venous drainage (CVR) using Onyx®. METHOD: Nine patients with DAVFs with direct cortical venous drainage were treated: eight type IV and one type III (Cognard). Treatment consisted of transarterial embolization using Onyx-18®. Immediate post treatment angiographies, clinical outcome and late follow-up angiographies were studied. RESULTS: Complete occlusion of the fistula was achieved in all patients with only one procedure and injection in only one arterial pedicle. On follow-up, eight patients became free from symptoms, one improved and no one deteriorated. Late angiographies showed no evidence of recurrent DAVF. CONCLUSION: We recommend that transarterial Onyx® embolization of DAVFs with direct cortical venous drainage be considered as a treatment option, while it showed to be feasible, safe and effective.
New guidelines for diagnosis and treatment of insomnia
Authors: Pinto Jr Luciano Ribeiro , Alves Rosana Cardoso , Caixeta Eliazor , Fontenelle John Araujo , Bacellar Andrea , Poyares Dalva , Aloe Flavio , Rizzo Geraldo , Minhoto Gisele , Bittencourt Lia Rita , Ataide Jr Luiz , Assis Márcia , Pradella-Hallinan Márcia , Pinto Maria Christina Ribeiro , Rodrigues Raimundo Nonato D , Hasan Rosa , Fonseca Ronaldo , Tavares Stella
Published: August 2010

The Brazilian Sleep Association brought together specialists in sleep medicine, in order to develop new guidelines on the diagnosis and treatment of insomnias. The following subjects were discussed: concepts, clinical and psychosocial evaluations, recommendations for polysomnography, pharmacological treatment, behavioral and cognitive therapy, comorbidities and insomnia in children. Four levels of evidence were envisaged: standard, recommended, optional and not recommended. For diagnosing of insomnia, psychosocial and polysomnographic investigation were recommended. For non-pharmacological treatment, cognitive behavioral treatment was considered to be standard, while for pharmacological treatment, zolpidem was indicated as the standard drug because of its hypnotic profile, while zopiclone, trazodone and doxepin were recommended.
Caracteristicas anatômicas da casca e produção de látex em plantas de seringueira não enxertadas
Authors: Mesquita Alessandro Carlos , Oliveira Luiz Edson Mota de
Published: August 2010

As estruturas envolvidas na produção de látex na seringueira são os laticíferos articulados. O objetivo deste estudo foi descrever aspectos anatômicos da casca em seringueiras não enxertadas com quatro, seis e oito anos, visando à seleção de materiais promissores. O material analisado foi obtido através do corte da casca à altura aproximada de 1,50 m do solo, chegando até o xilema da planta. Os cortes transversais foram preparados de acordo com as técnicas usuais de microtécnica vegetal. Os resultados permitem concluir, que a utilização de caracteres anatômicos (diâmetro das células), da espessura da casca e do diâmetro do caule, visando à seleção dos materiais de pés-francos com idades diferentes, apresentaram uma correlação significativa com a produção de látex.
Desmídias filamentosas (Conjugatophyceae) de um lago de inundação de águas pretas na Amazônia Central
Authors: Souza Karla Ferreira , Melo Sérgio
Published: August 2010

Com base em 109 amostras coletadas em diferentes fases do ciclo hidrológico nos anos de 2002 a 2004 no lago Cutiuaú, um ambiente de águas pretas localizado no Parque Nacional do Jaú na bacia do rio Negro, foi realizado um levantamento taxonômico das espécies de desmídias filamentosas. Foram identificadas 15 espécies distribuídas em sete gêneros, sendo Desmidium C. Agardh ex Ralfs, com sete espécies, o gênero que apresentou a maior riqueza específica, incluindo D. quadratum citado pela primeira vez para o estado do Amazonas. O gênero Groenbladia Teiling apresentou três espécies, enquanto os gêneros Bambusina Kützing ex Kützing, Hyalotheca Ehrenberg ex Ralfs, Phymatodocis Nordstedt, Spondylosium Brébisson ex Kützing e Teilingia Bourrelly, apresentaram uma única espécie. Em relação aos períodos do ciclo hidrológico, três táxons foram registrados no período de águas baixas, seis no de vazante, oito no de águas altas e 15, ou seja, todos foram observados no período de enchente.
Impactos do agrupamento do bambu Actinocladum verticillatum (Nees) McClure ex Soderstr. (POACEAE) sobre a vegetação lenhosa de duas fitofisionomias de Cerrado na transição Cerrado-Floresta Amazônica
Authors: Silvério Divino Vicente , Mews Henrique Augusto , Lenza Eddie , Marimon Beatriz Schwantes
Published: August 2010

Este estudo analisou os efeitos do agrupamento de uma espécie de bambu nativa do Cerrado (Actinocladum verticillatum) sobre a composição florística, diversidade e estrutura da vegetação lenhosa de um cerradão e de um cerrado típico adjacentes no Parque Municipal do Bacaba, Nova Xavantina-MT. Foram instaladas 60 parcelas de 10x10 m, sendo 30 no cerradão e 30 no cerrado típico. Em cada fitofisionomia, foram instaladas 15 parcelas em um sítio sem bambu (SB) e 15 em um sítio com cobertura estimada de folhagem de bambu superior a 90% (CB). Foram amostrados todos os indivíduos arbustivo-arbóreos com diâmetro a 30 centímetros do solo (DAS) ≥ 3 cm. Foi avaliada a riqueza, a diversidade de espécies, a similaridade florística, a distribuição de diâmetros e alturas e o índice de valor de importância das espécies (VI). De forma geral, os sítios CB das duas fitofisionomias apresentaram menores valores quanto ao número de indivíduos, espécies, gêneros, famílias, densidades e áreas basais em relação aos sítios SB, com redução mais acentuada nestes parâmetros no cerrado típico em relação ao cerradão. Os resultados sugerem que a ocupação do espaço e a redução da incidência luminosa causada pelas touceiras do bambu dificultam a germinação das sementes e o estabelecimento das plântulas de espécies arbustivo-arbóreas, selecionando as espécies mais tolerantes ao sombreamento modificando a composição florística e a estrutura da vegetação.
Detecção de rotavírus em um cão doméstico na cidade de Manaus-AM
Authors: Pimentel Renah Boanerges de Queiroz , Costa Cristóvão Alves da
Published: August 2010

Os rotavírus do grupo A, são frequentemente associados com gastroenterites em mamíferos e aves. O objetivo deste trabalho foi detectar a presença de rotavírus em fezes de cães sintomáticos e assintomáticos para diarréia aguda. Foram coletadas 32 amostras de fezes de cães. Todas as amostras foram submetidas à extração do RNA viral seguida da Eletroforese em Gel de Poliacrilamida (EGPA), onde se identificou apenas 1 (um) caso de infecção por rotavírus, em amostra assintomática. A análise do eletroferótipo mostrou um perfil 4:2:3:2 longo, e a homologia dos eletroferótipos de rotavírus humano e canino foi muito alta, sugerindo uma possível infecção interespécie.