bluuebunny/crossref_metadata_2025 huggingface dataset:
Undifferentiated giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation: a case report and review of the literature
Authors: Manouras Andreas , Genetzakis Michael , Lagoudianakis Emmanuel E , Markogiannakis Haridimos , Papadima Artemisia , Agrogiannis George , Gakiopoulou Hariklia , Kekis Panagiotis , Filis Konstantinos , Patsouris Efstratios
Published: June 2009

Introduction

Undifferentiated gallbladder carcinoma is a rare entity. Among unusual types of undifferentiated gallbladder carcinoma, giant cell type carcinoma is infrequent and, moreover, very few cases of such neoplasms with osteoclast-like giant cells have been documented. We report a case of undifferentiated gallbladder carcinoma presenting an unusual immunophenotype that was shown to be of giant cell type with sarcomatoid dedifferentiation infiltrated by osteoclast-like multinucleated cells.

Case presentation

An 84-year-old Greek man presented with right upper quadrant pain, high fever, rigors, anorexia and weight loss during the past month. Clinical examination revealed tenderness in the right upper abdominal quadrant and a palpable gallbladder. Blood tests showed elevated white blood-cell count and transaminases. Abdominal ultrasound and computed tomography demonstrated a markedly distended gallbladder, measuring 16 cm x 8 cm, with oedema and pericholecystic fluid, consistent with gallbladder empyema. After an open cholecystectomy and an uneventful recovery, the patient was discharged on the 4th postoperative day. On cut surface, a 2cm solid mass was identified, obstructing the lumen in the neck of the gallbladder. Histopathology and immunohistochemistry offered the diagnosis of an undifferentiated, giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation infiltrated with osteoclast-like giant cells.

Conclusions

Undifferentiated, giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation infiltrated with osteoclast-like giant cells is a very infrequent neoplasm. Controversy exists over its nature, as related knowledge remains incomplete. Thorough histopathological and immunohistochemical evaluation is imperative for diagnosis. Due to their rarity, the biological behaviour and prognosis of these tumours remain unclear.
A novel mutation in the ADA gene causing severe combined immunodeficiency in an Arab patient: a case report
Authors: Hellani Ali , Almassri Nidal , Abu-Amero Khaled K
Published: June 2009

Introduction

About 20% of the cases of human severe combined immunodeficiency are the result of the child being homozygous for defective genes encoding the enzyme adenosine deaminase. To our knowledge, the mutation pattern in Arab patients with severe combined immunodeficiency has never been reported previously.

Case presentation

A 14-month-old Arab boy had clinical features typical of severe combined immunodeficiency. His clinical picture and flow cytometric analysis raised the diagnosis of adenosine deaminase deficiency and prompted us to screen the adenosine deaminase gene for mutation(s). We detected a novel mutation in exon 9 of the adenosine deaminase gene (p.Arg282>Gln), which we believe is the cause of the severe combined immunodeficiency phenotype observed in our patient.

Conclusion

This is the first report of adenosine deaminase mutation in an Arab patient with severe combined immunodeficiency due to a novel pathogenic mutation in the adenosine deaminase gene.
Peripheral primitive neuroectodermal tumor of the urinary bladder in an Arab woman with history of squamous cell carcinoma: a case report
Authors: Al Meshaan Mohd Khaled , Nayef Marwan , Kwaider Talal , Otto Wolfgang , Katchy Ken C
Published: June 2009

Introduction

Peripheral primitive neuroectodermal tumors of the urinary bladder are rare and tend to occur in an older age group than do their counterparts in bones and soft tissue.

Case presentation

We report a case of peripheral primitive neuroectodermal tumor of the urinary bladder in a 67-year-old woman of Arab origin. She had undergone transurethral resection followed by chemotherapy because of pulmonary metastasized muscle-invasive squamous cell carcinoma of the bladder in 2005. One year later, she first presented with a history of repeated hematuria in our institution. Performing cystoscopy any tumor could be detected. Control cystoscopy two months later showed a tumor mass of 3 cm in diameter at another location than described for the first tumor. After perforating by transurethral resection partial bladder resection had to be done. Tissue specimen after pathological analysis revealed a peripheral primitive neuroectodermal tumor with tumor cells reactive to cluster of differentiation 99, neuron-specific enolase and S100 protein and stained negative for other markers such as cytokeratins, epithelial membrane antigen, desmin, smooth muscle actin, chromogranin and leucocyte common antigen. Staging computerized tomography was especially free from any hint on organ metastasis, but the patient died due to a cardiac problem only a few months later.

Conclusions

To the best of our knowledge, we report the eighth case of bladder peripheral primitive neuroectodermal tumors in literature and the first concerning an Arab patient. It is also the first presentation of a peripheral primitive neuroectodermal tumor patient with a history of squamous cell carcinoma of the bladder. As in other cases, expression of single-chain-type 1 glycoprotein and neural markers was positive and the disease was at an advanced stage at the time of diagnosis.
Axons find their way in the snow
Authors: Zou Yimin
Published: June 2009

In February 2009, Keystone, Colorado, hosted the third Symposium on `Axonal Connections: Molecular Cues for Development and Regeneration', organized by Marie Filbin, John Flanagan and Liqun Luo. Researchers from diverse backgrounds spent the week discussing the latest findings in axon guidance,synapse formation, dendrite development and axon regeneration. The meeting was held jointly with another Keystone Symposium on `Neurodegenerative Diseases:New Molecular Mechanisms', and the two meetings profited from the lively discussions fuelled with questions from both fields in the joint sessions,which featured topics of common interest, such as axon degeneration,regeneration and neural stem cells.
Pyrochlore to Fluorite Transitions – Ordering in Fluorites?
Authors: Whittle Karl R. , Cranswick Lachlan M. , Redfern Simon A.T. , Swainson Ian P. , Lumpkin Gregory R.
Published: June 2009

Two systems have been studied La2-xYxZr2O7 and La2-xYxHf2O7, as part of an on-going study of radiation tolerance in nuclear waste forms and related oxide materials. The structural effects of increasing Y content in La based zirconate and hafnate pyrochlores have been studied with neutron diffraction and electron microscopy. Results have shown a difference in structural stability for both the pyrochlore and fluorite phases within each system, including the presence of two-phase regions in both systems. In the zirconate, the two-phase region lies in the range x = 0.9-1.6. This is shifted to higher Y content in the hafnate system and lies in the range of x = 1.5 to approximately 1.8-1.9. In addition to the differences in phase stability, electron diffraction, predominantly down the [110] zone axis, has shown evidence for ordering in the form of structured diffuse scattering within the fluorite phases.
Length-scale Effects in Cascade Damage Production in Iron
Authors: Stoller R. E. , Kamenski P. J. , Osetsky Yu. N.
Published: June 2009

Molecular dynamics simulations provide an atomistic description of the processes that control primary radiation damage formation in atomic displacement cascades. An extensive database of simulations describing cascade damage production in single crystal iron has been compiled using a modified version of the interatomic potential developed by Finnis and Sinclair. This same potential has been used to investigate primary damage formation in nanocrystalline iron in order to have a direct comparison with the single crystal results. A statistically significant number of simulations were carried out at cascade energies of 10 keV and 20 keV and temperatures of 100 and 600K to make this comparison. The results demonstrate a significant influence of nearby grain boundaries as a sink for mobile defects during the cascade cooling phase. This alters the residual primary damage that survives the cascade event. Compared to single crystal, substantially fewer interstitials survive in the nanograined iron, while the number of surviving vacancies is similar or slightly greater than the single crystal result. The fraction of the surviving interstitials contained in clusters is also reduced. The asymmetry in the survival of the two types of point defects is likely to alter damage accumulation at longer times.
Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications
Authors: Farmer Joseph , El-dasher Bassem , Caro Magdalena Serrano de , Ferreira James
Published: June 2009

Corrosion of ferritic steels, including oxide dispersion strengthened (ODS) variants, in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such as beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li2BeF4) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 °C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. Electrochemical impedance spectroscopy has been used for the initial in situ study of an ODS ferritic steel in high-temperature molten fluoride salt environments, with the complex impedance spectra obtained at its open circuit corrosion potential (OCP) interpreted in terms of the basic components of the equivalent circuit, which include the electrolyte conductivity, the interfacial charge transfer resistance, and the interfacial capacitance. Such in situ measurement techniques may provide valuable insight into the degradation of materials under realistic conditions.
Fracture Mechanisms of Bone: A Comparative Study between Antler and Bovine Femur
Authors: Chen P.Y. , Sheppard F.A. , Curiel J.M. , McKittrick J.
Published: June 2009

In this study, fracture toughness of North American elk (Cervus elaphus canadensis) antler and bovine femur were measured using four-point bending tests on single-edge notched compact samples (ASTM C1421). Tests were conducted on crack growth directions longitudinal and transverse to the long axis of antler and bone in both dry and hydrated conditions to study the effects of fiber orientation and hydration. Fracture toughness results in the transverse orientation were much higher than that in the longitudinal orientation and increased with degree of hydration for both antler and bovine femur. The fracture toughness of antler was ∼ 50% higher than that of bovine femur. The highest fracture toughness value was obtained from the hydrated antler in the transverse orientation, which reached 10.31 MPa·m1/2 compared to that measured from bovine femur, which was 6.35 MPa·m1/2. The crack propagation and fracture surface were characterized using scanning electron microscopy. Toughening mechanisms, including crack deflection by osteons, uncracked ligament bridging, and microcracks formation, are observed and discussed. Comparisons between antler and bone are made.
Mapping the Micromechanical Properties of Cryo-sectioned Aortic Tissue with Scanning Acoustic Microscopy
Authors: Akhtar Riaz , Sherratt Michael J. , Watson Rachel E.B. , Kundu Tribikram , Derby Brian
Published: June 2009

Although the gross mechanical properties of ageing tissues have been extensively documented, biological tissues are highly heterogeneous and little is known concerning the variation of micro-mechanical properties within tissues. Here, we use Scanning Acoustic Microscopy (SAM) to map the acoustic wave speed (a measure of stiffness) as a function of distance from the outer adventitial layer of cryo-sectioned ferret aorta. With a 400 MHz lens, the images of the aorta samples matched those obtained following chemical fixation and staining of sections which were viewed with fluorescence microscopy. Quantitative analysis was conducted with a frequency scanning or V(f) technique by imaging the tissue from 960 MHz to 1.1 GHz. Undulating acoustic wave speed (stiffness) distributions corresponded with elastic fibre locations in the tissue; there was a decrease in wave speed of around 40 ms-1from the adventitia (outer layer) to the intima (innermost).
Bone-Bonding Ability of Anodized Titanium Plate Loaded With Hydroxyapatite Particles
Authors: Iwasaki Mitsunobu , Kudo Kohki , Shimada Kazuki , Matsuzaki Kohji , Hamanishi Chiaki
Published: June 2009

Submicron-sized hydroxyapatite (HAp) particles were loaded on the titanium plate by anodic oxidation over spark discharge voltage in HAp-containing bath. The biocompatibility and bioactivity were drastically improved by HAp deposition on the anodic oxide films. The affinity with living bone was the following order: anodized titanium plate with HAp > anodized titanium plate ≫ titanium. Bone-bonding strength between HAp-loaded titanium plate and living bone after 4 weeks' implant was much higher than that of anodized titanium plate.
Local Release of Basic Fibroblast Growth Factor (bFGF) through Silica Nanoparticles-laden Biomimic Matrix
Authors: Zhang Jin , Gardiner Richard B. , Mumin Abdul , Harris Richard
Published: June 2009

Basic fibroblast growth factor (bFGF), a protein, plays a key role in wound healing and blood vessel regeneration. However, most negative effectsin vivo, orin vitroresult from the over dosage of bFGF. Furthermore, it needs to keep the bFGF from protein denaturant. Thus, this study aims to develop a new delivery system based on silica nanoparticles (SiO2NPs) dispersed in collagen patch for delivery of the bFGF in a local and prolonged manner. In this research, SiO2NPs are used to encapsulate bFGF through a modified water-in-oil micro-emulsion. The bFGF-loaded nanoparticles afterwards are dispersed in the collagen-based matrix through a EDC cross-linking step. Thein vitrorelease kinetics of SiO2 NPs - encapsulated bFGF with and without collagen matrix have been monitored through ELISA. In addition, the cytotoxicity of SiO2NPs is investigated by studying the viability of Human Umbilical Vein Endothelial Cells (HUVEC) under the different concentrations of SiO2NPs. It has found the average diameter (d) for SiO2NPs encapsulating bFGF is 45 ± 8 nm with a loading efficiency of 72.5±3%. The maximum concentration of bFGF locally released from SiO2NPs impregnated collagen matrix can be monitored after 30 days, while bFGF released from SiO2NPs can be detected in 20 days. The further prolonged releasing after the nanoparticle-encapsulated bFGF laden collagen matrix is possibly due to the interaction between the nanoparticles and collagen matrix. In addition, the biocompatibility of the SiO2NP has been investigated. We found that SiO2NPs at the concentration of 50 μg/ml can still keep the cell alive. The results indicate that the nanoparticle-laden collagen matrix can locally deliver growth factor in a prolonged manner. This new delivery system may benefit to blood vessel regeneration and potentiate greater angiogenesis.
Optical stability of small-molecule thin-films determined by Photothermal Deflection Spectroscopy
Authors: Stella Marco , Della Pirriera Monica Beatriz , Puigdollers Joaquim , Bertomeu Joan , Voz Cristobal , Andreu Jordi , Alcubilla Ramon
Published: June 2009

In this paper the optical absorption properties of n-type C60and PTCDA, and p-type CuPc small molecule semiconductors are investigated by optical transmission and Photothermal Deflection Spectroscopy (PDS). The results show the usual absorption bands related to HOMO-LUMO transitions in the high absorption region of the transmission spectra. PDS measurements also evidences exponential absorption shoulders with different characteristic energies. In addition, broad bands in the low absorption level are observed for C60and PTCDA thin-films. These bands have been attributed to contamination due to air exposure. In order to get deeper understanding of the degradation mechanisms single and co-evaporated thin-films have been characterized by PDS. The dependence of the optical coefficient on exposure to light and air have been studied and correlated to the structural properties of the films (as measured by X-Ray Diffraction Spectroscopy). The results show that CuPc and PTCDA are quite stable against light and air exposure, while C60shows important changes in its absorption coefficient. The bulk heterojunctions show stability in agreement with what observed for single layers, since the absorption coefficient of CuPc:PTCDA is almost not altered after the degradation treatments, while CuPc:C60shows changes for low energy values.
Interaction of Hf Precursor with H2O-terminated Si(001): First Principles Study
Authors: Kim Dae-Hyun , Kim Dae-Hee , Seo Hwa-Il , Kim Yeong-Cheol
Published: June 2009

We investigated the reaction of HfCl4 molecules with a H2O terminated Si (001)-2×1 surface using density functional theory to understand the initial stage of atomic layer deposition (ALD) of HfO2. Half monolayer of H2O molecules were adsorbed on the buckled-down Si atoms of the Si dimers of the Si (001)-2×1 surface below the dissociation temperature of H2O and were dissociated into H and OH at room temperature. This process could make uniform and well-aligned −H and −OH’s on the Si (001) substrate. The reaction of a HfCl4 molecule was more favorable with -OH than -H. The reaction of the HfCl4 molecule with the -OH generated a HCl molecule, and the remaining HfCl3 was attached to the O atom. The first reaction of the HfCl4 molecule with −OH produced 0.21 eV energy benefit. The reaction of the second HfCl4 molecule with the most adjacent −OH of the first one produced 0.28 eV energy benefit. The third and fourth molecules showed same tendency with the first and second ones. The energy differences of the fifth and sixth HfCl4 reactions were -0.01 eV, 0.06 eV, respectively. Therefore, we found that the saturation Hf coverage was approximately 5/8 of the available −OH's, which was 2.08 × 1014 Hf/cm2. The result was well-matched with the experimental study of other group.
Electrical Resistance and Structural Changes on Crystallizaiton Process of Amorphous Ge-Te Thin Films
Authors: Saito Yuta , Sutou Yuji , Koike Junichi
Published: June 2009

GeTe-Sb2Te3 pseudobinary compounds are attracting considerable attention as phase change materials for optical disk and phase change random access memory (PRAM). In these compounds, Ge2Sb2Te5 (GST) has been used for an optical disk memory such as DVD-RAM because the crystallization by laser beam heating is very fast (∼20ns). Recently, the GST has been much considered as material for PRAM and, therefore, the electrical resistance change due to crystallization and the phase change by applying an electrical current have been widely investigated. On the other hand, although GeTe compound has been suggested as the phase change material for the optical disk by Chen et al in 1986, the study focusing on the phase change material for PRAM is limited. Since GeTe is known to show the phenomenon of electrical switching, this compound has a potential of PRAM. In this study, the electrical resistance and crystalline structural changes on crystallization process in Ge-Te thin films were investigated.

Films of amorphous Ge100–xTex (x : 46-94) with 200 nm thickness were deposited by sputtering of GeTe alloy target or co-sputtering of GeTe and Te targets on SiO2/Si substrates. In-situ electrical resistance measurements during heating process of these films were performed by two point probe method in a heating rate of 2∼50°C/min. X-ray diffraction (XRD) analysis was employed for the structural identification of thin films for 10-60° in 2′ using X-ray diffractometer with Cu-K. Transmission electron microscope (TEM) analysis was carried out to investigate the microstructure and to identify crystalline structure. The compositions of these films were confirmed by energy dispersive X-ray spectroscopy (EDS) attached TEM.

All as-deposited Ge-Te films were confirmed amorphous by XRD and TEM. From the in-situ electrical resistance measurements, it is found that resistance change with crystallization process depends on the composition and the stoichiometric GeTe compound shows abrupt electrical resistance change at around 190 °C. The crystallization temperature of GeTe was higher than that of GST and resistance difference between the amorphous and the crystal was also larger. While the electrical resistance of GST film gradually decreased with increasing temperature after the crystallization at around 160 °C, that of GeTe film showed small temperature dependence after crystallization. It was found by X-ray measurement observation that the amorphous GeTe compound film crystallized first into a cubic state, and then into a stable rhombohedral state by further heating. The crystallization kinetics of Ge-Te thin films will be also presented.
Opto-electrical characterization and X-ray Mapping of large-volume cadmium zinc telluride radiation detectors
Authors: Yang Ge , Bolotnik Aleksey E , Camarda Giuseppe , Cui Yonggang , Hossain Anwar , Yao Walter , Kim Ki Hyun , James Ralph
Published: June 2009

Large-volume cadmium zinc telluride (CZT) radiation detectors would greatly improve radiation detection capabilities and, therefore, attract extensive scientific and commercial interests. CZT crystals with volumes as large as hundreds of centimeters can be achieved today due to improvements in the crystal growth technology. However, the poor performance of large-volume CZT detectors is still a challenging problem affecting the commercialization of CZT detectors and imaging arrays. We have employed Pockels effect measurements and synchrotron X-ray mapping techniques to investigate the performance-limiting factors for large-volume CZT detectors. Experimental results with the above characterization methods reveal the non-uniform distribution of internal electric field of large-volume CZT detectors, which help us to better understand the responsible mechanism for the insufficient carrier collection in large-volume CZT detectors.
Copper Sulfide Assisted Recrystallization of Cu-poor CuInS2 Observed in-situ by Polychromatic X-ray Diffraction
Authors: Rodriguez-Alvarez Humberto , Mainz R. , Weber A. , Marsen B. , Schock H.W.
Published: June 2009

The microstructural changes during heating of bi-layers of Cu-poor CuInS2 and CuS under different sulfur excess conditions were studied. This was done by means of energy dispersive X-ray diffraction of polychromatic synchrotron radiation in a vacuum setup where the sulfur pressure conditions can be controlled. Understood as the formation of a new microstructure, the recrystallization of the Cu-poor CuInS2 phase was characterized by a change in the reflection profile (from Cauchy-type to Gauss-type), the reduction of the breadth and a subsequent normalized-intensity increase of the 112 reflection. The Cauchy component of the breadth was used to monitor the recrystallization under different sulfur and heating rate conditions. The main results are: a) Cu availability for the consumption of the CuIn5S8 phase is a pre-requisite for recrystallization, b) in presence of the Cu2-xS phase, increased sulfur pressure enhances recrystallization.
Comparison of ZnS-based Buffer Layers by Chemical Bath Deposition and Atomic Layer Deposition
Authors: Platzer-Bjöerkman Charlotte , Uhl Alexander
Published: June 2009

In this work we compare ZnS-based buffer layers prepared by atomic layer deposition, ALD, and chemical bath deposition, CBD. Both material and device properties are compared. CBD buffer layers are amorphous with a Zn(OH,S) composition while ALD buffer layers used in devices are crystalline with a Zn(O,OH,S) composition. Devices with ALD buffer layers are stable while for CBD, large lightsoaking effects are seen. Stable devices with CBD buffer layers are obtained by including an ALD-(Zn,Mg)O layer on top of the CBD layer.
Influence of the Cu Content on Structural and Vibrational Properties in Polycrystalline CuGaSe2 Thin Films
Authors: Witte Wolfram , Kniese Robert , Powalla Michael
Published: June 2009

We studied CuGaSe2 (CGS) thin films with different Cu contents by means of X-ray diffraction (XRD) and micro-Raman spectroscopy. The CGS absorbers were deposited by co-evaporation on Mo/glass substrates. We found a clear shift of the CGS Raman mode frequencies to lower values with increasing Cu/Ga ratio. This is in direct correlation with the increasing lattice constants a and c extracted from XRD patterns. Influence of stress on the obtained results can be neglected, because very small stress values below 50 MPa were determined with the sin2Ψ method.
On the Thermoelectric Potential of Inverse Clathrates
Authors: Falmbigl Matthias , Rogl Peter F , Bauer Ernst , Kriegisch Martin , Müeller Herbert , Paschen Silke
Published: June 2009

In the context of a general survey on the thermoelectric potential of cationic clathrates, formation, crystal chemistry and physical properties were investigated for novel inverse clathrates deriving from Sn19.3Cu4.7P22I8. Substitution of Cu by Zn and Sn by Ni was attempted to bring down electrical resistivity and lower thermal conductivity. Materials were synthesized by mechanical alloying using a ball mill and hot pressing. Structural investigations for all specimens confirm isotypism with the cubic primitive clathrate type I structure (lattice parameters a = ˜1.1 nm and space group type Pm-3n). Studies of transport properties evidence holes as the majority charge carriers. Thermal expansion data, measured in a capacitance dilatometer from 4 to 300 K on Sn19.3Cu1.7Zn3P19.92.1I8, compare well with literature data available for Sn24P19.62.4Br8and for an anionic type I clathrate Ba8Zn8Ge38. From the rather complex crystal structure including split atom sites and lattice defects thermal conductivity in inverse clathrates is generally low. Following Zintl rules rather closely inverse clathrates tend to be semiconductors with attractive Seebeck coefficients. Thus for thermoelectric applications the main activity will have to focus on achieving low electrical resistivity in a compromise with still sufficiently high Seebeck coefficients.
Effect of Morphology of ZnO Nanowire Arrays on Interfacial Shear Strength in Carbon Fiber Composites
Authors: Galan Ulises , Ehlert Gregory , Lin Yirong , Sodano Henry Angelo
Published: June 2009

ZnO nanowire arrays are grown on carbon fiber to enhance the interface strength of a polymer matrix composite without degrading the base fiber and in-plane strength of the composite. The morphology of the nanowire array is controlled during growth to create nanowires with different aspect ratios to elucidate the structure-property relations of the interphase. Nanowires are shown to double the composite interfacial shear strength at an intermediate nanowire length, indicating that an optimal point exists and the interface can be engineered to maximize the interfacial enhancement. Furthermore, the observed effect of the morphology on interface strength indicates that the bond between the ZnO nanowire array and the carbon fiber is quite strong, more than twice as strong as the interaction between the matrix and control fiber.
Development of a Chemiresistor Sensor for Polypropylene Degradation Products
Authors: Dirk Shawn M. , Sawyer Patricia S. , Bernstein Robert , Hochrein James M. , Washburn Cody M. , Howell Stephen W. , Graf Darin C.
Published: June 2009

This paper presents the development of a sensor to detect the oxidative and radiation induced degradation of polypropylene. Recently we have examined the use of crosslinked assemblies of nanoparticles as a chemiresistor-type sensor for the degradation products. We have developed a simple method that uses a siloxane matrix to fabricate a chemiresistor-type sensor that minimizes the swelling transduction mechanism while optimizing the change in dielectric response. These sensors were exposed with the use of a gas chromatography system to three previously identified polypropylene degradation products including 4-methyl-2-pentanone, acetone, and 2-pentanone. The limits of detection 210 ppb for 4-methy-2-pentanone, 575 ppb for 2-pentanone, and the LoD was unable to be determined for acetone due to incomplete separation from the carbon disulfide carrier.
Investigation of Characteristics of Multi-Function ZnO Thin Film Deposited with Various Argon and Oxygen Ratios
Authors: Wu Jong-Shin , Hsu Che-Wei , Cheng Tsung-Chieh , Yang Chun-Hui , Shen Yi-Ling , Wu Sheng-Yao , Huang Wen-Hsien
Published: June 2009

The ZnO thin film was successfully deposited on a glass substrate at RT by a RF reactive magnetron sputtering method. Structural, chemical, optical, and hydrophilic/hydrophobic properties are measured by using a surface profilometer, an x-ray diffractometry (XRD), an x-ray photoelectron spectroscopy (XPS), a UV-VIS spectrophotometer, and a contact angle system, respectively. Results show that the deposition rate decreases with increasing O2/(Ar+O2) ratio. Otherwise, the best stoichiometric and quality of ZnO thin film was observed at 0.30 of O2/(Ar+O2) ratio by the smallest FWHM and the strong O-Zn bonds. Regardless of O2/(Ar+O2) ratio effect or thickness effect, high transmittance (> 86%) in the visible region is observed, while the UV-shielding characteristics depend upon both the magnitude of film thickness. The film thickness plays a more prominent role in controlling optical properties, especially in the UV-shielding characteristics, than the O2/(Ar+O2) ratio. However, the hydrophobic characteristics can be obtained when the glass coating with ZnO thin films. In general, with properly coated ZnO thin film, we can obtain a glass substrate which is highly transparent in the visible region, has good UV-shielding characteristics, and possesses highly hydrophobic characteristics (self-clean capability), which is highly suitable for applications in the glass industries.
A Single-Step Route Towards Large-Scale Deposition of Nanocomposite Thin Films Using Preformed Gold Nanoparticles
Authors: Wang Weiliang , Cassar Kevin , Sheard Steve , Dobson Peter , Hurst Simon , Bishop Peter , Parkin Ivan
Published: June 2009

We have been developing noble metal nanoparticles and nanocomposites for large scale application to glass surfaces. The novel functionality of the nanocomposites is attributed to the properties of both the metal nanoparticles and host matrix. Here a single-process route to nanocomposite thin films by spray deposition technique has been investigated. Preformed gold nanoparticles have been incorporated into several different transition metal oxides (TiO2, SnO2, ZnO). The nanocomposite films showed intense coloration due to the surface plasmon resonance effects of gold nanoparticles embedded in the host matrix. The gold nanoparticles were found well embedded into the host metal oxides homogeneously. This film deposition method can easily be scaled up and is compatible with current industrial on-line processes.
The Nature and Characterization of Nanoparticles
Authors: Kohli Rajiv
Published: June 2009

Nanosize particles are of fundamental and practical interest for developing advanced materials and devices and micro and nanostructures. As feature sizes shrink, nanoparticle contamination is also becoming increasingly important to achieve and maintain high product yields. In order to employ appropriate material and product development strategies, or institute preventive assembly and remediation strategies to control nanoparticle contamination, it is essential to understand the nature of nanoparticles and to characterize these particles. Particles in the size range 0.1 nm to 100 nm present unique challenges and opportunities for their imaging and characterization. Critical information for this purpose is the number and size of the particles, their morphology, and their physical and chemical structure. Because of this importance, many advances and new developments have been made in qualitative and quantitative characterization techniques for particles in this size range, including neutron holography, three dimensional atom probe imaging, ultrafast microscopy and crystallography, magnetic resonance force microscopy, and high-resolution x-ray crystallography of non-crystalline structures. It is now possible to completely characterize nanoparticles from 0.1 nm to 100 nm size. A brief review of the nature of nanoparticles is presented and recent developments in selected characterization techniques are described.
Hydrophobic Metallic Nanorods coated with Teflon Nanopatches by Glancing Angle Deposition
Authors: Khudhayer Wisam J , Sharma Rajesh , Karabacak Tansel
Published: June 2009

Introducing a hydrophobic property to vertically aligned hydrophilic metallic nanorods was investigated experimentally and theoretically. First, platinum nanorod arrays were deposited on flat silicon substrates using a sputter Glancing Angle Deposition Technique (GLAD). Then a thin layer of Teflon (nanopatches) was partially deposited on the tips of platinum nanorod at a glancing angle of  = 85° as well as at normal incidence ( = 0°) for different deposition times. We show that GLAD technique is capable of depositing ultrathin isolated Teflon nanopatches on selective regions of nanorod arrays due to the shadowing effect during GLAD. Contact angle measurements on Pt/Teflon nano-composite have shown contact angle values as high as 138°, indicating a significant increase in the hydrophobicity of originally hydrophilic Pt nanostructures. Finally, a 2D simplified wetting model utilizing Cassie and Baxter theory of heterogeneous surfaces has been developed to explain the wetting behavior of Pt/Teflon nanocomposite.
Validade de instrumento epidemiológico para rastrear H. pylori entre pacientes dispépticos
Authors: Santos Iná Silva , Sassi Raúl A Mendoza , Minten Gicele Costa , Tuerlinckx Giovana Costa , Valle Neiva C J , Oliveira Sandro S de , Boccio Jose , Barrado Domingo Andrés , Mariani Samanta Gaertner , Carriconde Joaquim Freitas
Published: June 2009

OBJETIVO:Validar um escore epidemiológico para identificar dispépticos positivos para Helicobacter pylori. MÉTODOS: Estudo transversal realizado com 434 indivíduos entre 18 e 45 anos de idade, portadores de dispepsia não investigada, usuários de unidades básicas de saúde de Pelotas (RS), entre 2006 e 2007. Dispepsia foi diagnosticada conforme Roma-II. O padrão-ouro para presença de H. pylori foi o teste respiratório com 13C-uréia. Analisou-se a associação entre H. pylori e variáveis independentes por regressão logística. O escore foi construído a partir de odds ratios ajustadas. Foram calculadas a sensibilidade, especificidade e valores preditivos. RESULTADOS: Dentre os dispépticos, a prevalência de H. pylori foi 74% (IC 95%: 69;77,7) e esteve associada diretamente à idade e número de irmãos na infância e inversamente à escolaridade, sendo essas variáveis utilizadas na construção do escore. Os valores do escore variaram de 3-9. Escores entre 7, 8 e 9 apresentaram sensibilidade, respectivamente, de 36,6%, 22,3% e 11,1%; e valores preditivos positivos 87,8%, 90,9% e 92,1%. Sem a aplicação do escore, três de cada quatro dispépticos receberiam tratamento para H. pylori, com a aplicação, menor número de dispépticos seriam encaminhados para tratamento (um em cada três, seis e 11, respectivamente, com os pontos de corte entre 7 e 9), porém às custas de alta taxa de casos falso-negativos. CONCLUSÕES:O escore não foi válido para identificação seletiva de dispépticos candidatos a tratamento erradicador para H. pylori. Diferentemente do recomendado para países desenvolvidos, a alta prevalência de H. pylori torna a estratégia testar-e-tratar inapropriada para uso nos países em desenvolvimento.
Umidade de equilíbrio da madeira de angelim vermelho (Dinizia excelsa Ducke ), guariúba (Clarisia racemosa Ruiz & Pav.) e tauarí vermelho (Cariniana micrantha Ducke) em diferentes condições de temperatura e umidade relativa
Authors: Baraúna Edy Eime Pereira , Oliveira Valmir Souza de
Published: June 2009

A umidade de equilíbrio deve ser determinada para o local onde a madeira será empregada. Isto pode ser feito através da determinação da umidade das amostras de madeira expostas às condições ambientais de temperatura e umidade relativa em ensaios de campo, de laboratório equipado com câmara de climatização ou estimativas por meio de modelos matemáticos. Neste trabalho foi determinada a umidade de equilíbrio da madeira - UEM do angelim vermelho (Dinizia excelsa Ducke), guariúba (Clarisia racemosa Ruiz & Pav.) e tauarí vermelho (Cariniana micrantha Ducke ), em duas condições de temperatura e três de umidade relativa em câmara de climatização. Encontrou-se diferenças entre a umidade de equilíbrio estimada pela equação de Simpson (1971) e o valor real determinado em câmara climática. Na simulação de ensaio a 25º C de temperatura e umidade relativa de 40% a UEM ficou em média 26,6% superior ao valor estimado pela equação de Simpson (1971), constituindo-se na maior variação. A menor variação foi de 2,1% registrada na espécie angelim vermelho na condição de 35º C e 80% de umidade relativa. A equação de Simpson, no geral, tendeu a superestimar os valores de UEM nas três espécies.
Produtividade de quatro espécies arbóreas de Terra Firme da Amazônia Central
Authors: Andrade Eleonora Alvarenga , Higuchi Niro
Published: June 2009

A análise da produtividade individual de espécies permite descrever o comportamento das mesmas em ecossistemas florestais. O objetivo deste trabalho foi analisar a produtividade de quatro espécies arbóreas em um período de seis anos (2000-2006) em uma área de terra firme na região de Manaus, AM. A produtividade foi estimada indiretamente por meio da utilização de equações alométricas individuais geradas e dados de inventários florestais. Foram selecionadas Pouteria reticulata Eyma (Sapotaceae), Micrandra siphonioides Benth. (Euphorbiaceae), Protium hebetatum Daly (Burseraceae) e Eschweilera wachenheimii Sand (Lecythidaceae) por apresentarem alto índice de valor de importância na área. As equações foram geradas a partir de um arquivo de dados; devido ao reduzido número de indivíduos por espécie foi necessária a utilização de um método não paramétrico, sendo escolhido o "Jackknife". As equações foram aplicadas às árvores das espécies selecionadas localizadas em duas parcelas permanentes com as informações dos inventários florestais dos anos de 2000, 2002, 2004 e 2006. Os resultados mostram indícios de confiabilidade do método, as equações geradas apresentaram altos valores de coeficiente de determinação (R² > 0,93) e baixos valores de erro padrão da estimativa (s y.x < 0,692), evidenciando sua consistência e precisão. As taxas de produtividade foram específicas para cada espécie, entretanto, o padrão de produtividade das espécies E. wachenheimii, P. reticulata e P. hebetatum foram semelhantes, diferindo da M. siphonioides. A maior produtividade se refere à espécie M. siphonioides e a menor à P. hebetatum. A variação da produtividade intra-específica foi superior à variação inter-específica, com P. reticulata apresentando o maior coeficiente de variação.
Características sedimentares fluviais associadas ao grau de reservação da mata Ciliar - Rio Urumajó, Nordeste Paraense
Authors: Brito Roney Nonato Reis de , Asp Nils Edvin , Beasley Colin Robert , Santos Helane Súzia Silva dos
Published: June 2009

Os rios são os agentes mais importantes no transporte dos sedimentos para as áreas mais baixas dos continentes e para o mar. Além dos efeitos diretos do clima local, a cobertura vegetal atua no controle da descarga e no suprimento de sedimentos. Sendo assim, o presente trabalho enfoca o padrão de distribuição granulométrica do rio Urumajó (nordeste paraense) em relação ao estado de preservação da mata ciliar. Cinco estações (A-E) foram estabelecidas de forma a registrar um transecto da nascente à foz do rio. Nessas estações, procedeu-se com a caracterização da mata ciliar, bem como do seu grau de preservação. Além disto, elaborou-se um perfil transversal ao canal para cada estação, com coleta de cinco amostras de sedimentos em cada perfil. Estes foram submetidos à análise granulométrica, que resultou na obtenção de valores da média, mediana, seleção, assimetria e curtose. Com os resultados foi possível reconhecer as características sedimentares normais do rio, onde areia média é a principal classe granulométrica transportada. Foram observadas nas estações A e C a clara tendência das amostras serem moderadamente bem selecionadas e aproximadamente simétricas, com dominância absoluta de areia média, o que está diretamente relacionado ao seu bom estado de preservação. Significativas variações granulométricas nas estações B, D e E foram associadas com o processo erosivo das margens do rio, conseqüência da degradação da mata ciliar. Além disso, foi constatada a influência das correntes de maré na sedimentologia da estação E, subsidiando também a delimitação do ambiente estuarino que se encontra associado ao canal fluvial.
Aproveitamento de alimentos de origem animal pela tartaruga-da-amazônia: Podocnemis expansa criada em cativeiro
Authors: Almeida Cauê Guion de , Abe Augusto Shinya
Published: June 2009

Foi realizado um trabalho para determinar o aproveitamento alimentar da farinha de carne e ossos (FCO), farinha de vísceras de aves (FVA) e farinha de peixe (FP) em tartaruga-da-amazônia, por meio dos coeficientes de digestibilidade aparente (CDA) da matéria seca (MS), proteína bruta (PB), extrato etéreo (EE) e energia bruta (EB). Os animais experimentais foram 136 filhotes provenientes do Projeto Quelônios da Amazônia, no estado do Mato Grosso, mantidos em caixas com renovação de água e temperatura média de 29ºC. Os CDA foram determinados com dietas contendo 0,1% do marcador óxido de crômio III (Cr2O3). Os CDA da MS, PB, EE e EB foram, respectivamente, de 79,10; 87,61; 93,83 e 79,61% para FCO; 92,45; 94,89; 96,55 e 92,71% para FV e 93,53; 95,13; 94,05 e 93,18% para FP. Os melhores coeficientes foram obtidos com a farinha de peixe e a farinha de vísceras de aves.
Observações sobre a ocorrência de Mosca-Negra-dos-Citros, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Sternorrhyncha: Aleyrodidae) no estado do Amazonas
Authors: Ronchi-Teles Beatriz , Pena Marcia Reis , Silva Neliton Marques
Published: June 2009

A mosca-negra-dos-citros (Aleurocanthus woglumi Ashby) é uma importante praga dos citros de origem asiática. Foi detectada no Brasil pela primeira vez em Belém-PA em 2001. Este trabalho tem como objetivo registrar a ocorrência de mosca-negra-dos-citros no estado do Amazonas, sua distribuição geográfica e estudos de biologia em condições de laboratório. A mosca-negra encontra-se atualmente disseminada em mais da metade dos municípios paraenses. No Amazonas foi detectada em junho de 2004 em Manaus e atualmente encontra-se disseminada em toda a área urbana deste município, ocorrendo também em Itacoatiara, Rio Preto da Eva e Iranduba. Em observações feitas em condições de laboratório em Manaus-AM, foi verificado que o ciclo de ovo-adulto foi de 71,76±2,07 dias, caracterizando como uma espécie multivoltina.
Parasitóides (Hymenoptera: Braconidae) de Anastrepha Schiner (Diptera: Tephritidae) no estado do Acre
Authors: Thomazini Marcílio José , Albuquerque Elizângela Sampaio de
Published: June 2009

Este trabalho relata a primeira ocorrência de parasitóides em moscas-das-frutas do gênero Anastrepha Schiner no estado do Acre. No município de Bujari foram encontrados os braconídeos Opius bellus Gahan (72,5%), Doryctobracon areolatus (Szépligeti) (26,8%) e Utetes anastrephae (Viereck) (0,7%) associados a A. obliqua (Macquart) em frutos de taperebá (Spondias mombin L.), com parasitismo de 29,5%. No município de Rio Branco, em frutos de goiaba (Psidium guajava L.), ocorreu somente D. areolatus em A. obliqua com parasitismo de 2,7%.
Comparação entre dois sistemas de pontuação para o teste informatizado de percepção de emoções em fotos
Authors: Bueno José Maurício Haas , Miguel Fabiano Koich , Primo Ricardo , Muniz Monalisa , Couto Gleiber , Noronha Ana Paula Porto
Published: June 2009

Este trabalho teve o objetivo principal de comparar dois sistemas de atribuição de pontos às respostas de sujeitos no Teste Informatizado de Percepção de Emoções: concordância com o consenso e concordância com critérios definidos por especialistas, com base na teoria relacionada à inteligência emocional e na teoria de resposta ao item. Participaram do estudo 55 sujeitos de ambos os sexos, de 18 a 74 anos, cujos protocolos foram avaliados pelos dois métodos de pontuação. Embora a correlação entre os dois métodos de pontuação tenha sido elevada, a atribuição de pontos por concordância com especialistas resultou em correlações item-total significativamente mais elevadas que as pontuações por concordância com o consenso. Os resultados sugerem que o desenvolvimento de instrumentos para avaliação de habilidades relacionadas à inteligência emocional deve priorizar o critério da concordância com especialistas, e mostra como a teoria de resposta ao item pode ser útil no processo de investigação e escolha desses critérios.
Questões acerca da percepção sonora de harmônicos: a função das variáveis sexo e aprendizagem
Authors: Antune Deborah Christina , Gouveia Jr Amauri
Published: June 2009

Este trabalho objetivou verificar o desempenho de homens e mulheres em uma tarefa de discriminação perceptiva de sons e o efeito de aprendizagem anterior sobre esta discriminação. O experimento foi realizado com 17 homens e 17 mulheres, submetidos individualmente a uma sessão de coleta de dados composta de questionário padronizado e de teste de discriminação com vinte tentativas gravadas em um CD-ROM. A análise estatística dos dados indicou diferenças de desempenho entre pessoas com e sem experiência musical prévia [F(1,33)=14,69, p<0,001]. Embora não significativo, as mulheres apresentaram melhor desempenho no grupo sem experiência prévia, e no grupo com experiência, os homens apresentaram melhor desempenho. Os dados indicam que, embora haja diferenças sexuais na percepção sonora, a experiência parece ser o fator mais importante neste tipo de discriminação.
Stress no cotidiano da equipe de enfermagem e sua correlação com o cronótipo
Authors: Ferreira Luciane Ruiz Carmona , De Martino Milva Maria Figueiredo
Published: June 2009

Este estudo teve como propósitoclassificar o cronótipo dos funcionários da equipe de enfermagem e identificar a presença de stress correlacionado ao cronótipo e turno de trabalho. Foi realizado em hospital privado da cidade de Limeira, estado de São Paulo, com 87 sujeitos, dos diferentes setores e turnos de trabalho. Os instrumentos utilizados foram o Inventário de Sintomas de Stress de Lipp e o Questionário de Indivíduos Matutinos e Vespertinos. Verificou-se que 74,7% dos sujeitos estavam adequados ao turno de trabalho; no entanto, 55,4% apresentavam sintomas de stress, demonstrando correlação estatisticamente significativa (Teste Exato de Fisher p=0,035). Verificou-se também stress nos sujeitos com maior tempo de serviço na instituição, com diferença significativa (Teste Exato de Fisher p=0,003). Concluiu-se que a maioria dos sujeitos estava adequada ao turno de trabalho, de acordo com seu cronótipo, porém mesmo nestes indivíduos o stress foi observado, levando à confirmação de dados obtidos em outras pesquisas quanto ao caráter estressante da profissão.