bluuebunny/crossref_metadata_2025 huggingface dataset:
Systemic immune response and peripheral blood cell count in patients with a history of breast cancer
Authors: Šrámek Vlastislav , Melichar Bohuslav , Študentová Hana , Kalábová Hana , Vrána David , Lukešová Lucie , Adam Tomáš , Hlídková Eva , Juráňová Jarmila , Krčmová Lenka Kujovská , Solichová Dagmar
Published: December 2013

The aim of the present study was to evaluate the association between changes in peripheral blood cell count and neopterin concentrations in patients with a history of breast cancer. Peripheral blood cell count, serum ferritin, serum neopterin and urinary neopterin concentrations were determined in 61 patients with a history of breast cancer and 74 control subjects. Hemoglobin, relative lymphocyte count and absolute lymphocyte count were lower, and relative neutrophil count, ferritin and serum neopterin concentrations were significantly higher in breast cancer patients than in controls. Compared to controls, the difference in hemoglobin concentration was statistically significant only in patients with active disease. Significant negative correlations were observed between urinary neopterin and hemoglobin as well as between serum neopterin and relative lymphocyte counts in breast cancer patients. Increased ferritin concentrations were associated with a history of hypertension, but higher absolute lymphocyte counts were associated with hypertension only in subjects without history of cancer. In conclusion, in patients with a history of breast cancer, anemia is associated with disease activity and systemic immune activation. Ferritin concentrations are increased in subjects with hypertension.
Modulation of phenylalanine and tyrosine concentrations by ischemia and guanosine in neuronal PC12 cells
Authors: Thauerer Bettina , Geisler Simon , Fuchs Dietmar , Baier-Bitterlich Gabriele
Published: December 2013

Survival of neurons is dependent on the presence of trophic and non-trophic factors. We have previously observed the protective capacity of purine nucleosides in hypoxic neuronal cell cultures. Guanosine appeared especially interesting with respect to its remarkable neurite-stimulating aptitude. Here we report the effect of ischemic stress and guanosine on the concentration of the essential amino acids phenylalanine and tyrosine, in culture supernatants of PC12 cells. In ischemic neuronal cultures, a substantial rise of phenylalanine and tyrosine levels was observed, indicating inhibition of cellular metabolism due to neuronal stress. Elevated phenylalanine and tyrosine concentrations were reduced by the addition of guanosine. Guanosine even down-regulated the ratio of phenylalanine to tyrosine. Results may support current efforts to propagate guanosine as a neuroprotective and neuroregenerative substance.
Strength Evaluation and Energy-Dissipation Behavior of Fiber-Reinforced Polymer Concrete
Authors: Toufigh Vahid , Toufigh Vahab , Saadatmanesh Hamid , Ahmari Saeed
Published: December 2013

There is a growing demand in finding a replacement for ordinary Portland cement (OPC) because of inherent weakness in mechanical properties and durability of the OPC. In this study, polymer concrete (PC) is investigated as a potential replacement for OPC-based concrete. PC contains a mixture of epoxy resin and aggregates for which the epoxy resin serves as the cementing agent. Processes of forming PC and FRPC (fiber-reinforced polymer concrete) have been developed and are presented in detail. Behavior of PC and FRPC under compressive, tensile, and impact loadings are determined through experiments. The studies are conducted in three phases with objectives of optimizing the bulk density and strength of the medium. Our experimental results indicate that the PC and FRPC specimens exhibit significantly higher compressive and tensile strength and impact toughness as compared to OPC. However, FRPC specimens have higher tensile strength and toughness relative to PC specimens, but the two sets are comparable in compressive strength. Furthermore, PC, as well as FRPC, have a faster curing rate as compared to OPC (less than 5 days for full curing).
Ungekühlte Thermoelement-Luftbrückenstruktur für
Anwendungen im THz-Bereich
Authors: Schinkel U. , Keßler E. , Ihring A. , Dillner U. , Hänschke F. , May T. , Meyer H.-G.
Published: December 2013

Eine Luftbrückenstruktur wurde entwickelt, auf der ein
Dünnschicht-Thermoelement angeordnet ist. Dieses Thermoelement
dient als Abschlusswiderstand einer Antenne und gleichzeitig als
Temperatursensor [1]. Die Brückenstruktur wurde
mittels Oberflächenmikromechanik hergestellt. Die thermischen
Eigenschaften der Luftbrückenstruktur wurden durch
Computersimulationen untersucht, und basierend auf diesen
Ergebnissen wurde eine geeignete Technologie entwickelt, um eine
hochleistungsfähige thermoelektrische Terahertz-Sensorstruktur
herzustellen. Die Messung der elektrischen Empfindlichkeit dieser
Thermoelement-Luftbrückenstruktur ergab eine NEP von
18 pW/Hz1/2 unter Vakuumbedingungen und von
67 pW/Hz1/2 an Luft.
Development of a Microfluidic GHz Impedance Cytometer
Authors: Haandbæk Niels , Bürgel Sebastian C. , Heer Flavio , Hierlemann Andreas
Published: December 2013

This article presents a novel microfluidic impedance cytometer
enabling dielectric characterization of single cells at
frequencies up to 500 MHz. The dielectric properties of cells at
lower frequencies contain information about their size and
membrane capacitance. The increased frequency range of the
presented cytometer potentially allows for characterization of
intracellular components, such as vacuoles or the cell nuclei. We
demonstrate the overall capabilities of the cytometer through
discrimination of polystyrene beads from Chinese hamster ovary
(CHO) cells. The discrimination is based on the difference in
dielectric properties at frequencies up to 500 MHz.
Different expression of TSH receptor and NIS genes in thyroid cancer: role of epigenetics
Authors: D'Agostino Maria , Sponziello Marialuisa , Puppin Cinzia , Celano Marilena , Maggisano Valentina , Baldan Federica , Biffoni Marco , Bulotta Stefania , Durante Cosimo , Filetti Sebastiano , Damante Giuseppe , Russo Diego
Published: December 2013

The TSH receptor (TSHR) and sodium/iodide symporter (NIS) are key players in radioiodine-based treatment of differentiated thyroid cancers. While NIS (SLC5AS) expression is diminished/lost in most thyroid tumors, TSHR is usually preserved. To examine the mechanisms that regulate the expression of NIS and TSHR genes in thyroid tumor cells, we analyzed their expression after inhibition of ras–BRAF–MAPK and PI3K–Akt–mTOR pathways and the epigenetic control occurring at the gene promoter level in four human thyroid cancer cell lines. Quantitative real-time PCR was used to measure NIS and TSHR mRNA in thyroid cancer cell lines (TPC-1, BCPAP, WRO, and FTC-133). Western blotting was used to assess the levels of total and phosphorylated ERK and Akt. Chromatin immunoprecipitation was performed for investigating histone post-translational modifications of the TSHR and NIS genes. ERK and Akt inhibitors elicited different responses of the cells in terms of TSHR and NIS mRNA levels. Akt inhibition increased NIS transcript levels and reduced those of TSHR in FTC-133 cells but had no significant effects in BCPAP. ERK inhibition increased the expression of both genes in BCPAP cells but had no effects in FTC-133. Histone post-translational modifications observed in the basal state of the four cell lines as well as in BCPAP treated with ERK inhibitor and FTC-133 treated with Akt inhibitor show cell- and gene-specific differences. In conclusion, our data indicate that in thyroid cancer cells the expression of TSHR and NIS genes is differently controlled by multiple mechanisms, including epigenetic events elicited by major signaling pathways involved in thyroid tumorigenesis.
MOLECULAR EVOLUTION OF GPCRS: Ghrelin/ghrelin receptors
Authors: Kaiya Hiroyuki , Kangawa Kenji , Miyazato Mikiya
Published: December 2013

After the discovery in 1996 of the GH secretagogue-receptor type-1a (GHS-R1a) as an orphan G-protein coupled receptor, many research groups attempted to identify the endogenous ligand. Finally, Kojima and colleagues successfully isolated the peptide ligand from rat stomach extracts, determined its structure, and named it ghrelin. The GHS-R1a is now accepted to be the ghrelin receptor. The existence of the ghrelin system has been demonstrated in many animal classes through biochemical and molecular biological strategies as well as through genome projects. Our work, focused on identifying the ghrelin receptor and its ligand ghrelin in laboratory animals, particularly nonmammalian vertebrates, has provided new insights into the molecular evolution of the ghrelin receptor. In mammals, it is assumed that the ghrelin receptor evolution is in line with the plate tectonics theory. In contrast, the evolution of the ghrelin receptor in nonmammalian vertebrates differs from that of mammals: multiplicity of the ghrelin receptor isoforms is observed in nonmammalian vertebrates only. This multiplicity is due to genome duplication and polyploidization events that particularly occurred in Teleostei. Furthermore, it is likely that the evolution of the ghrelin receptor is distinct from that of its ligand, ghrelin, because only one ghrelin isoform has been detected in all species examined so far. In this review, we summarize current knowledge related to the molecular evolution of the ghrelin receptor in mammalian and nonmammalian vertebrates.
New Perturbation Method for Predicting Solute Segregation Energies for Symmetric Tilt Grain Boundaries
Authors: Lu Shijing , Brenner Donald W.
Published: December 2013

Solute atoms in dilute alloys have been shown to segregate at grain boundaries and stabilize them against grain growth. At present, most theories of the stabilization of nanostructured alloys do not account for the detailed atomic structure of the interfaces, but instead rely on averaged segregation energies. One of the reasons for this is the daunting task of determining segregation energies for a large number of possible sites in a given microstructure. We have developed a new approach to predicting and organizing interface structures in alloys that takes advantage of perturbation techniques and a disclination structural units model (DSUM) developed previously to describe grain boundary structure and properties in pure systems. The fundamental idea is to treat dilute alloys as a perturbed form of the pure metal systems whose energy can be determined by the DSUM. This paper introduces this method and gives a preliminary validation by comparing segregation energies for zirconium solute segregating to a grain boundary in copper calculated via the perturbation method and full atomistic simulations.
Radial Growth Model for Conical Nanobridge in Resistive Switching Memory Devices
Authors: Liu Tong , Kang Yuhong , El-Helw Sarah , Potnis Tanmay , Orlowski Marius
Published: December 2013

A phenomenological model has been proposed for the radial growth of the copper or silver nanobridge in the conductive bridge random access memory devices. In this model, the growth rate of the bridge is proportional to the local ion flux based on the hopping mechanism. Due to the differences of the local electric field, the growth rate is different along a conical shape nanobridge. The model accounts for the growth rate difference by introducing a geometrical form factor. Based on the model, the top and bottom radii are predicted for truncated conical copper nanobridge. The model is validated with data obtained on Cu/TaOx/Pt resistive devices.
Structural Analysis of Pore Seal Layer Fabricated by Wet-process on Porous Low-k Films
Authors: Ono Shoko S. , Kayaba Yasuhisa , Suzuki Tsuneji , Kohmura Kazuo , Tanaka Hirofumi
Published: December 2013

Pore sealing has become a critical issue for the implementation of porous low-k dielectrics and for realizing acceptable reliability performance of the interconnect. This study focuses on fabrication of ultra-thin, conformal and plasma resistant pore seal layer and on understanding parameters playing a role in sealing the surfaces of porous low-k films. It was found that 2.5 nm-thick pore seal layer shows a perfect toluene seal property for the porous low-k film whose pore radius is 1.48 nm. The pore seal layer still show a good toluene seal property after irradiation of He plasma at 250°C for 10 sec. The increments of dielectric constant by applying the pore seal layer and by the He plasma irradiation for 10 sec are 0.04 and 0.03, respectively. Interestingly, all of toluene seal property, refractive index of the bottom part of the film and dielectric constant started to deteriorate after irradiation of He plasma for 20 sec. It was suggested that when toluene seal property degrades, plasma would start diffusing into pores and both refractive index of the bottom part of the film and k value start to increase.
Self-learning kinetic Monte Carlo model for arbitrary surface orientations
Authors: Latz Andreas , Brendel Lothar , Wolf Dietrich E.
Published: December 2013

While the self-learning kinetic Monte Carlo (SLKMC) method enables the calculation of transition rates from a realistic potential, implementations of it were usually limited to one specific surface orientation. An example is the fcc (111) surface in Latz et al. 2012, J. Phys.: Condens. Matter 24, 485005. This work provides an extension by means of detecting the local orientation, and thus allows for the accurate simulation of arbitrarily shaped surfaces. We applied the model to the diffusion of Ag monolayer islands and voids on a Ag(111) and Ag(001) surface, as well as the relaxation of a three-dimensional spherical particle.
Reactivity Analysis of the AunAgm (6 ≤ n + m ≤ 12) Bimetallic Clusters with Selected Proportions
Authors: Molina Bertha , Soto Jorge R. , Rojas Francisco E. , Castro Jorge J.
Published: December 2013

It is well known that Au-Ag bimetallic nanoparticles have better performance in catalytic processes compared to their counterpart pure clusters. The improvement in their catalytic properties has been attributed to a kind of synergy between the gold and silver atoms that has not been fully understood. Unlike pure clusters, there are very few studies on the catalytic behavior of the Au-Ag binary nanoparticles. From the theoretical point of view, in the subnanometer regimen, the bimetallic Au-Ag clusters present a challenging problem, since by combining the different gold and silver relativistic effects, a variety of skeletal geometric structures and homotopic distributions are obtained. In particular, pure gold has favorable planar structure even up to 16 atoms, while silver begins to favor 3D arrangements from 5-7 atoms. This dissimilar behavior produces a diverse population of 2D and 3D coexisting binary clusters, whose properties strongly depend of the Au/Ag mixing ratio. In this work we use the relativistic approach ZORA-DFT to model the AunAgm (with 4 ≤ (n + m) ≤ 12) binary nanoclusters in selected proportions (1:1, 3:1, 5:1) in the gas-phase and we study their reactivity from the descriptors based in the condensed Fukui indexes obtained from an NBO electronic population analysis.
Efficient blue luminescence from colloidal CdSe quantum-dot quantum-well nanocrystals
Authors: Lu Y. , Cao X. A.
Published: December 2013

CdS/CdSe/ZnS quantum dot quantum well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique. CdSe QWs with a well width of 1.05 nm emitted blue light at 467 nm with a spectral full-width-at-half-maximum of ∼30 nm. It was found that a 3-monolayer ZnS outer cladding layer can effectively passivate the QDQW structures, leading to a ∼35% quantum yield (QY) of the QW photoluminescence. QDQW light-emitting diodes (LEDs) with blue QW electroluminescence (EL) were fabricated. The devices with an emitting layer comprising QDQWs embedded in a poly(N-vinylcarbazole) host were five times brighter than LEDs based on closely-packed QDQWs. However, the overall EL of the devices was dominated by interface state emission due to poor charge injection into the QDQWs.
Electrophoretic Deposition of Carbon Nanotubes for Interconnections in Microelectronics
Authors: Lim Chiew Keat , Wang Yadong , Wu Shixin
Published: December 2013

Carbon nanotubes (CNTs) have been considered as a promising interconnect material to replace the solder bump used in the flip chip package because of their special electrical, mechanical and thermal properties, which may promote both the performance and reliability of the flip chip packaging. In this paper, electrophoretic deposition (EPD) of CNTs on substrates has been demonstrated for the interconnect application. EPD is a simple, low cost and high throughput process that is capable to produce densely packed film with good homogeneity at low temperature. By altering the electric fields and deposition time during the EPD process, the thickness of the CNTs film could be controlled. In this study, multi-walled carbon nanotubes (MWCNTs) were successfully coated on the various substrates using the EPD method. A highly uniform CNTs microstructure film with thickness over 5 µm was achieved. In addition, the selective depositions of CNTs on the pre-defined bond pads to form CNTs bumps were also accomplished. By employing typical flip-chip bonding technique, high density CNTs bumps were aligned to form a test chip/host substrate interconnects. The electrical conductivity of the CNTs interconnects was carried out using four-point probe measurement. Reliable electrical contacts with linear relationship in the current-voltage (I-V) characteristic suggesting ohmic behaviour were attained. The overall resistances extracted were also relatively low. These superior electrical properties have demonstrated that the CNTs bumps deposited using EPD method is a viable way to serve as an alternative to current metal solder interconnects material such as Sn-Pb alloys. Hence, it offers a promising interconnect application in the quest for device miniaturization in microelectronic industry.
ZnO Nanostructured Diodes - Enhancing Energy Generation through Scavenging Vibration
Authors: Briscoe Joe , Jalali Nimra , Loh Leonard , Shoaee Safa , Wooliams Peter , Stewart Mark , Cain Markys , Weaver Paul M. , Durrant James R. , Dunn Steve
Published: December 2013

Recent developments on the use of the piezoelectric effect in ZnO nanorod-based p-n junctions for energy harvesting applications are presented. Two types of junctions are used. The first is a hybrid p-n device combining the semiconducting polymer poly(3,4-ethylene-dioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) with ZnO nanorods. The second type of junction is an all-inorganic junction between n-type ZnO nanorods and p-type CuSCN. It is shown that both these diodes can be produced on flexible plastic substrates, which generate a voltage output when bent. The voltage output of the ZnO/PEDOT:PSS diodes are measured across a range of resistive loads while bending to find a maximum power point of 12 μWcm-2 at 4 kΩ. It is shown that a voltage output is also generated when this structure is vibrated acoustically. The ZnO/CuSCN diode is sensitized to sunlight with a Ru-based dye to form a photovoltaic device. It is shown that the device efficiency can be increased by application of acoustic vibrations. This is attributed to the electric field generated by the piezoelectric effect in ZnO affecting the charge-carrier recombination at the ZnO surface.
First-Principles Modeling for Current-Voltage Characteristics of Resistive Random Access Memories
Authors: Miyazaki Takehide , Nakamura Hisao , Nishio Kengo , Shima Hisashi , Akinaga Hiroyuki , Asai Yoshihiro
Published: December 2013

We present results of first-principles non-equilibrium Green’s function calculations for current-voltage (IV) characteristics of the electrode/HfO2/electrode model systems. In order to investigate the effect of the electrode materials on the IV characteristics, we considered two transition metals for electrode, Ta and W, which are both body-centered-cubic elemental metals but have different valence numbers. We simulated the ON state by placing oxygen vacancies in the HfO2 layer while the OFF state was modeled with HfO2 without oxygen vacancies. At the OFF state, no electric current flowed for -1 V up to +1 V, as expected. At the ON state, however, we found that the absolute current for the Ta electrode was twice as large as that for the W electrode. The analysis of the IV characteristics shows that the electronic coupling between Ta and HfO2 is substantially stronger than that between W and HfO2. Our study demonstrates the importance of the matching between electrode and insulator materials to achieve a high ON- to OFF-current ratio in ReRAMs at a low bias.
Mechanics of quasi-1D ZnO nanostructures for energy harvesting
Authors: Rinaldi Antonio , Araneo Rodolfo , Pea Marialilia , Notargiacomo Andrea
Published: December 2013

The mechanical properties of ZnO nanowires are the “enabling factor” for piezotronic nanogenerators. Examining the size effects entail the determination of both elastic (i.e. the Young’s Modulus, E) and failure strength (e.g. fracture, fatigue, buckling, etc.) properties of ZnO nanostructures for nanogenerators. An investigation directed to both types of effects is presented here for the first time. On one hand the strength size effects are pointed out and discussed in the framework of a generalized Weibull framework that is set forward for ZnO NWs. On the other hand, the implications of the size effects on elasticity properties are discussed and quantified using numerical simulations. The results demonstrate that the stiffening of smaller NWs can adversely affect the performance in a non-negligible manner, suggesting that both mechanical size-effects have to be considered for design purposes.
The Microstructure and Local Piezoelectric Response in Polymer Nanocomposites with Different Ferroelectric Crystalline Additions
Authors: Kiselev Dmitry A. , Malinkovich Mikhail D. , Parkhomenko Yuriy N. , Solnyshkin Alexandr V. , Bogomolov Alexey A. , Silibin Maxim V. , Gavrilov Sergei A. , Shvartsman Vladimir V. , Lupascu Doru C.
Published: December 2013

In this work, we report on local ferroelectric and piezoelectric properties of nanostructured polymer composites P(VDF-TrFE)+x(Ba,Pb)(Zr,Ti)O3 (x = 0 - 50 %). High-resolution imaging of ferroelectric domains, local polarization switching, and polarization relaxation dynamics were studied by piezoresponse force microscopy. In particular, we found that (Ba,Pb)(Zr,Ti)O3 inclusions usually show a strong unipolar piezoresponse signal, as compared to the polymer matrix. By scanning under high dc voltage the films can be polarized uniformly under both positive and negative electric fields. Stability of the polarized state is discussed.
Ab initio studies of the structure and the interaction of cellulose IIII crystal
Authors: Ueda Kazuyoshi , Ishikawa Tetsuya , Miyamoto Hitomi , Hayakawa Daichi
Published: December 2013

Cellulose is one of the most abundant renewable resources and has high potential for the use as a future energy and materials for the chemical industries. We have investigated the crystal structure of cellulose IIII by using first principle density functional theory (DFT) calculation. The geometry optimization was performed with variable-cell relaxation with the Quantum ESPRESSO program package. We used Perdew-Burke-Ernzerhof (PBE) functional and compared the results with long-range van der Waals type correction term approach (PBE-D). The results are in good agreement with the experimentally obtained crystal structure of cellulose IIII when we used the PBE-D. Although the calculated cell parameters were slightly smaller than the experimental one, it can be well explained to include the thermal expansion effect in the experimental condition of ambient temperature. From the optimized crystal structure, the CH/O interactions included in the crystal structure were evaluated using NBO method. In this work, we showed that the density functional calculation is a powerful method to investigate the detail structure and the arrangement in the crystal and the nano-structured materials.
Two-contact Circular Test Structure for Determining Specific Contact Resistivity
Authors: Pan Y. , Reeves G. K. , Leech P. W. , Tanner P. , Holland A. S.
Published: December 2013

As ohmic contacts decrease in size and approach nanoscale dimensions, accurate electrical characterization is essential, requiring the development of suitable test structures for this task. We present here a new test structure derived from the standard three-contact circular transmission line model (CTLM) [1], for determining the specific contact resistivity of ohmic contacts. This test structure minimizes sources of error which arise from the CTLM by – (i) reducing the number of contacts within one test pattern from three to two, (ii) ensuring the assumption of equipotential metal contacts used in modelling is more easily attained experimentally, and (iii) allowing the fabrication of reduced geometrical dimensions essential for determining low specific contact resistivity values. The analytical expressions are presented and experiment results are undertaken to demonstrate the accuracy of the technique. There are no error corrections required for determining contact parameters using the presented test structure.
Horizontal carbon nanotube interconnects for advanced integrated circuits.
Authors: Dijon Jean , Chiodarelli Nicolo , Fournier Adeline , Okuno Hanako , Ramos Raphael
Published: December 2013

Horizontal carbon nanotube (CNT) interconnects are fabricated using a novel integration scheme yielding record wall densities >1013 shell/cm2, i.e. close to the density required for implementation in advanced integrated circuits. The CNTs are grown vertically from individual via structure and subsequently flipped onto the horizontal wafer surface. Various electrode designs are then used to produce different geometries of metal-to-tube contact such as side contact or end contact. CNT lines - 50 to 100 nm wide and up to 20 µm long - are realized and electrically characterized. The sum of the contact resistances from both ends of the lines is close to 500 Ω for 100 nm diameter lines which leads to a specific contact resistance of 1.6 10-8 Ω.cm2 per tube. With the developed technology, post-annealing of the contact does not improve the resistance values. Both chromium and palladium are used as contact metal. While contact resistance is equivalent with the two metals, the resistance per unit length of the lines does change and is better with palladium. This dependence is explained using a tunnelling model which shows that statistics of individual tube-metal contact is required to properly model the electrical results. Direct experimental evidences showing that only a part of the CNTs in the bundle is electrically connected are also given. Our best line resistivity achieved is 1.6mΩ.cm which is among the best results published for horizontally aligned CNTs and the only one with a realistic geometry for future VLSI interconnects.
3D TSV - Influence of electrolyte composites and anneal temperatures to copper protrusion and planarization
Authors: Rudolph Catharina , Wachsmuth Holger , Bartusseck Irene , Parthenopoulos Michael , Goerner Loana , Boettcher Mathias , Grafe Juergen , Wolf Juergen M.
Published: December 2013

The motivation of this study is to provide answers to questions rising with 3D stacking of semiconductor chips. This includes the development and validation of concepts for 1) Through Silicon Via (TSV) formation, 2) metal layer build-up, 3) various types of assembly and packaging concepts and methods, as well as 4) process characterization.

The investigations discussed here have been conducted on test wafer (ATEC2) developed by Fraunhofer IZM-ASSID. This design contains dedicated test structures which have been implemented to enable different unit processes and allows easy physical analysis. One of those test structures has been used to study the impact of the TSV density on the stress generation after TSV fill, anneal and CMP (chemical mechanical planarization) including copper protrusion and planarization behaviour. First results of the interaction between different TSV plating bath chemicals, anneal procedures and wafer bow obtained using test wafer ATEC1 were already presented during ICPT 2011.

The process flow applied in this investigation was (1) TSV filling by electro-plating, (2) anneal, and (3) CMP. Physical analysis including inline metrology has been conducted between all process steps.

The test wafers processed were divided into two groups according to the utilized copper plating bath chemistries. The copper TSV metallization was carried out by electro-chemical deposition in plating bath chemicals from two different suppliers. 3D microscope inspection was conducted for surface analysis. After TSV filling the copper surface shows protrusion on top of the TSVs and ring-shaped non-uniformities around the filled TSV. These structures were analysed after each step of the process flow.

An anneal process was conducted after TSV plating. The annealing temperature was varied to investigate its influence on the material properties (protrusion caused by copper recrystallization) and the dip behaviour. The experiments were accomplished at 250 degree Celsius and above.

Afterwards all test samples were processed by CMP with different selective slurries and analysed by AFM (atomic force microscopy) and optical methods. Bow and warpage measurements of the test wafers taken after each process step have been analysed.

Our investigation has demonstrated the influence of the additives on the behaviour of different plating bath chemistries during temperature treatment (copper recrystallization) and therefore also the planarization behaviour after CMP.
Coherent Clustering of GdN in Epitaxial GaN:Gd Thin Film
Authors: Wu Mingjian , Erwin Steven C. , Trampert Achim
Published: December 2013

We present an in-depth transmission electron microscopy (TEM) study about the character of the Gd atom distribution in epitaxial GaN:Gd thin films grown by molecular beam epitaxy. High-resolution TEM (HRTEM) imaging reveals local lattice distortions of dimensions of a few atom planes only. Geometric phase analysis of HRTEM lattice images quantifies the associated displacement field. The results are explained by means of thin coherently strained GdN clusters with platelet shape being located along the basal plane. This is consistent with the observations obtained from strain contrast dark-field TEM images. Theoretically derived structure models provided by calculations based on density functional theory are used to simulate the HRTEM contrast and to determine the corresponding displacement field for matching the experimental data. Best fit is achieved in case of a coherent GdN bi-layer cluster that conclusively reflects the energy favorable configuration. The formation of the platelet clusters is explainable in the framework of spinodal decomposition.
Kinetics of spinodal decomposition and strain energy effects in Cu-Ni(Fe) nanolaminates
Authors: Jankowski Alan F.
Published: December 2013

The phase transformation of spinodal decomposition proceeds without nucleation and is affected by the alloy composition, temperature, interfaces and gradient energy, as well as the presence of lattice strain. As a consequence, a coherent spinodal can be depressed well below the chemical spinodal within the miscibility gap. Phase separation from a solid solution within the spinodal leads to the formation of characteristic composition wavelengths. In the nickel-based alloy system, a nanolaminate structure is used to initially create an artificial composition fluctuation with unique nanoscale wavelengths. The direct measurement of diffusivity at low temperatures in Cu-Ni and Cu-Ni(Fe), from the spinodal towards room temperature, requires sensitivity to the nanoscale fluctuations in composition. For this purpose, x-ray diffraction scans are used to assess changes in the short-range order of the composition fluctuation and the corresponding changes in the gradient energy, from which an evaluation of lattice distortion effects reveals a peak in strain energy for 2-3 nm composition wavelengths.
Indium Antimonide (InSb) Cavity Resonators based on Planar Plasmonic Terahertz Waveguide
Authors: Shourie Ranjana J. , Satyanarayan M. N. , Umesh G.
Published: December 2013

We present the studies of Terahertz (THz) Semiconductor-Insulator-Semiconductor (SIS) Planar Plasmonic waveguide of Indium Antimonide (InSb) with cavities along the waveguide acting as resonator. The Surface Plasmon Polariton (SPP) modes were confined in the SI interface and resonance behavior and filtering functionality of the device were demonstrated. The transmission characteristic of the structure depends on the interference effects between the SPP mode passing through the cavity and the one returning from the cavity. These effects were observed by studying the transmission from the SIS waveguide as a function of frequency and cavity length and proving analytically using the analogy with microwave transmission line network. Furthermore, we present the SIS cavity resonator’s transmission characteristics which vary with changes in the dielectric constant of the insulator region. Such a study was proposed to incorporate in the structure for sensing of biomolecules in THz region.
Surfactant Mediated Slurry Formulations for Ge CMP Applications
Authors: Basim G. Bahar , Karagoz Ayse , Chen Long , Vakarelski Ivan
Published: December 2013

In this study, slurry formulations in the presence of self-assembled surfactant structures were investigated for Ge/SiO2 CMP applications in the absence and presence of oxidizers. Both anionic (sodium dodecyl sulfate-SDS) and cationic (cetyl trimethyl ammonium bromide-C12TAB) micelles were used in the slurry formulations as a function of pH and oxidizer concentration. CMP performances of Ge and SiO2 wafers were evaluated in terms of material removal rates, selectivity and surface quality. The material removal rate responses were also assessed through AFM wear rate tests to obtain a faster response for preliminary analyses. The surfactant adsorption characteristics were studied through surface wettability responses of the Ge and SiO2 wafers through contact angle measurements. It was observed that the self-assembled surfactant structures can help obtain selectivity on the silica/germanium system at low concentrations of the oxidizer in the slurry.
The Thermal Effects of CMP as a Particle Augmented Mixed Lubrication Tribosystem
Authors: Srivastava Gagan , Higgs C . Fred
Published: December 2013

Most chemical mechanical polishing (CMP) researchers assume that the polishing occurs in the mixed-lubrication regime, where the applied load on the wafer is supported by the hydrodynamic slurry pressure and the contact stress generated during the pad-wafer contact. Consequently, the particle augmented mixed lubrication (PAML) approach has been employed as an extremely high-fidelity asperity-scale mixed-lubrication CMP model in the past. Recently, a more computationally efficient PAML approach, PAML-lite, which considers the slurry’s fluid and particle dynamics, the pad/wafer contact mechanics, and the resulting material removal, was introduced. The current work presents the PAML-lite framework with the isothermal assumption relaxed. As a result, wafer-scale interfacial temperatures during CMP can be predicted by considering asperity heating and dissipation of the heat into the solid and fluid media in the sliding contact.
Hematoma intraprotuberancial
Authors: Tenuto Rolando A. , Cruz Oswaldo Ricciardi
Published: December 2013

Os autores apresentam um caso de hematoma intraprotuberancial com bloqueio do trânsito do liqüido cefalorraquidiano na porção média do quarto ventrículo. Os sinais neurológicos e a evolução clínica do caso afastavam-se daqueles observados nos processos hemorrágicos maciços ao nível da ponte. O tratamento cirúrgico, uma vez verificada a impossibilidade da excisão, consistiu em derivação do trânsito liquórico por meio da abertura da lâmina terminalis. O caso evolveu favoràvelmente.
Qualidade física de um cambissolo sob sistemas de manejo
Authors: Mota Jaedson Cláudio Anunciato , Freire Alcione Guimarães , Assis Júnior Raimundo Nonato de
Published: December 2013

A Chapada do Apodi vem se destacando como um promissor polo de fruticultura irrigada em virtude da potencialidade agrícola dos seus solos, que são submetidos a diferentes tipos de manejo, condicionando mudanças em seus atributos físicos. Este trabalho teve como objetivo avaliar fisicamente um Cambissolo cultivado com mamoeiro (Carica papaya L.), sob dois sistemas de manejo, comparado com um sob vegetação nativa secundária. Foram coletadas amostras de solo com estruturas deformada e indeformada para determinação de: granulometria, argila dispersa em água, densidade do solo e de partículas, estabilidade de agregados, carbono orgânico e resistência à penetração. Foram calculados o grau de floculação das argilas e o teor de matéria orgânica. No campo, foi realizado ensaio de condutividade hidráulica do solo. Os dados experimentais foram analisados considerando o delineamento inteiramente casualizado, adotando-se para todas as análises o esquema em parcela subdividida 3 x 3 x 5 (dois sistemas de manejo do solo - plantio do mamoeiro em sulco e camalhão - e mata nativa secundária; três camadas de solo - 0,0-0,1; 0,1-0,2; e 0,2-0,3 m; e cinco repetições), exceção para a condutividade hidráulica, em que se adotou o esquema fatorial 3 x 2 x 5 (dois sistemas de manejo do solo e mata nativa secundária; duas tensões - 0 e 5 hPa; e cinco repetições). Foram aplicados os testes de Kolmogorov-Smirnov para verificar a normalidade dos dados, o F para a análise de variância e o de Tukey para a comparação de médias, todos a 5 %. Concluiu-se que a hipótese de que os sistemas de cultivo pioram os solos fisicamente foi refutada, indicando que a qualidade dos atributos do solo sob cultivo, em geral, está mantida ou melhorada em relação à condição atual da mata nativa secundária; o decréscimo do teor de matéria orgânica, da porcentagem de agregados estáveis na classe de 4,76-2,00 mm de diâmetro e do diâmetro médio ponderado em solo cultivado, apesar de ainda estarem distantes de limites considerados críticos, é indicador da necessidade de adoção de práticas de manejo que evitem o desencadeamento de um processo de degradação do solo; e os indicadores de qualidade foram sensíveis às alterações provocadas pelos sistemas de manejo do solo e, portanto, podem ser utilizados como fonte para a interpretação da dinâmica de processos físicos do solo no tempo.
Mineralization of organic phosphorus in soil size fractions under different vegetation covers in the north of Rio de Janeiro
Authors: Rita Joice Cleide de Oliveira , Gama-Rodrigues Antonio Carlos , Gama-Rodrigues Emanuela Forestieri , Zaia Francisco Costa , Nunes Danielle Aparecida Duarte
Published: December 2013

In unfertilized, highly weathered tropical soils, phosphorus (P) availability to plants is dependent on the mineralization of organic P (Po) compounds. The objective of this study was to estimate the mineralization of total and labile Po in soil size fractions of > 2.0, 2.0-0.25 and < 0.25 mm under leguminous forest tree species, pasture and "capoeira" (secondary forest) in the 0-10 cm layer of a Red-Yellow Latosol after 90 d of incubation. The type of vegetation cover, soil incubation time and soil size fractions had a significant effect on total P and labile P (Pi and Po) fraction contents. The total average Po content decreased in soil macroaggregates by 25 and 15 % in the > 2.0 and 2.0-0.25 mm fractions, respectively. In contrast, there was an average increase of 90 % of total Po in microaggregates of < 0.25 mm. Labile Po was significantly reduced by incubation in the > 2.0 (-50 %) and < 0.25 mm (-76 %) fractions, but labile Po increased by 35 % in the 2.0-0.25 mm fraction. The Po fraction relative to total extracted P and total labile P within the soil size fractions varied with the vegetation cover and incubation time. Therefore, the distribution of P fractions (Pi and Po) in the soil size fraction revealed the distinctive ability of the cover species to recycle soil P. Consequently, the potential of Po mineralization varied with the size fraction and vegetation cover. Because Po accounted for most of the total labile P, the P availability to plants was closely related to the mineralization of this P fraction.
Rill erosion on an oxisol influenced by a thin compacted layer
Authors: Thomaz Edivaldo Lopes
Published: December 2013

The presence of compacted layers in soils can induce subprocesses (e.g., discontinuity of water flow) and induces soil erosion and rill development. This study assesses how rill erosion in Oxisols is affected by a plow pan. The study shows that changes in hydraulic properties occur when the topsoil is eroded because the compacted layer lies close below the surface. The hydraulic properties that induce sediment transport and rill formation (i.e., hydraulic thresholds at which these processes occur) are not the same. Because of the resistance of the compacted layer, the hydraulic conditions leading to rill incision on the soil surface differed from the conditions inducing rill deepening. The Reynolds number was the best hydraulic predictor for both processes. The formed rills were shallow and could easily be removed by tillage between crops. However, during rill development, large amounts of soil and contaminants could also be transferred.
Avaliação das visitas domiciliárias por estudantes e pelas famílias: uma visão de quem as realiza e de quem as recebe
Authors: Asso Rie Nadia , Affonso Vivian Regina , Santos Simone Carvalho , Castanheira Bruna Eulálio , Zaha Mariana Sayuri , Losada Daniele Moraes , Santos Janiele dos
Published: December 2013

A Faculdade de Medicina de Marília (Famema) é reconhecida por favorecer o ensino baseado na prática e centrado no estudante. Os estudantes são inseridos em Unidades de Saúde da Família (USF), onde interagem com a comunidade no desenvolvimento de ações - reflexões - ações, por meio da realização de visitas domiciliárias durante os dois primeiros anos dos cursos de Enfermagem e Medicina. Tais visitas são consideradas ferramentas para a compreensão e o cuidado em necessidades de saúde da família. Dessa maneira, elas têm por objetivo englobar os aspectos sociais, psicológicos e econômicos do indivíduo. Objetivo: Esta pesquisa avalia comparativamente a opinião dos estudantes e das famílias que realizaram e receberam visitas domiciliárias. Métodos: Trata-se de um estudo descritivo e quantitativo que informa a opinião das famílias e dos estudantes a respeito das visitas domiciliárias. Conclusões: As famílias e os estudantes consideram importante a valorização e o aprimoramento da prática, visando à construção humanizada do processo saúde-doença, incentivando, desde o princípio, a formação acadêmica e o vínculo integral entre profissional da saúde e paciente.
Integração básico-clínica no internato médico: Psiquiatria e Farmacologia
Authors: Lazarini Carlos Alberto , Goulart Flávia Cristina
Published: December 2013

O presente estudo avaliou o ganho de conhecimentos de estudantes do curso médico que participaram de uma atividade integradora básico-clínica de Farmacologia e Psiquiatria no quinto ano, bem como verificou a opinião deles quanto à relevância em participar dessa atividade. Foi realizado estudo quali-quantitativo, utilizando avaliação pré e pós-teste, e a técnica do Discurso do Sujeito Coletivo (DSC) para a análise do conteúdo linguístico. Observou-se aumento significativo na porcentagem de acertos no pós-teste em relação ao pré-teste (p < 0,001). As ideias centrais obtidas na análise do DSC foram: atividade muito pertinente; ampliação desta atividade para outros estágios; dificuldade nas disciplinas básicas; aplicação de avaliação cognitiva; e participação ativa do professor nas discussões. Estes resultados sugerem que a integração entre a Farmacologia e as atividades práticas do internato em Psiquiatria possibilitou ampliar conceitos de Farmacologia, tornando o aprendizado significativo. Embora os estudantes tenham apontado a necessidade de melhor ajuste da atividade, o seu nível de aceitação foi verbalizado por meio da sugestão de que ela se estenda aos demais estágios do quinto ano.
Tecnologias de informação e comunicação e ensino semipresencial na educação médica
Authors: Goudouris Ekaterini Simões , Giannella Taís Rabetti , Struchiner Miriam
Published: December 2013

O ensino médico vem enfrentando desafios para modificar suas práticas pedagógicas e estrutura curricular. As tecnologias de informação e comunicação (TICs) podem auxiliar no enfrentamento de muitos desses desafios. Tendo em vista esse cenário, este estudo tem como objetivo caracterizar as formas de apropriação de uma Ferramenta de Autoria de cursos na Internet em processos formativos semipresenciais de graduação, pós-graduação, educação continuada e extensão na área médica, no contexto da UFRJ. Com base nas análises, foi possível identificar o perfil de utilização das TICs e discutir os resultados, a partir dos ambientes virtuais de aprendizagem construídos pelos professores, de acordo com as seguintes categorias: unidades acadêmicas de origem; disciplinas e níveis de ensino envolvidos; configuração de áreas de conhecimento dos cursos semipresenciais; conformação das equipes docentes dos cursos; recursos de conteúdo e de comunicação utilizados; e atividades pedagógicas adotadas.
Iniciação às práticas de saúde: bricolagem na seleção de conteúdos
Authors: Pedrosa José Ivo
Published: December 2013

O tema Práticas de Saúde apresenta-se como polissêmico, possibilitando múltiplas abordagens teóricas e metodológicas. Para definir o conteúdo da disciplina Iniciação às Práticas de Saúde do curso médico da Universidade Federal do Piauí, operou-se a bricolagem entre inúmeros significados de práticas de saúde, ordenando e conectando dimensões da prática médica aos princípios do SUS e ao sentido de emancipação e autonomia da prática pedagógica, apontando que temas dessa natureza podem ser contextualizados e organizados sob a forma de disciplina utilizando-se a bricolagem para articular aspectos aparentemente isolados e invisíveis, cujo sentido é atribuído intencionalmente pelo professor.
Estimativa do comportamento do fogo em queimas experimentais sob povoamentos de Pinus elliottii
Authors: Batista Antonio Carlos , Beutling Alexandre , Pereira José Fernando
Published: December 2013

Foram realizadas 23 queimas experimentais em um talhão de Pinus elliottii da Estação Experimental de Rio Negro-PR, município de Rio Negro, pertencente à Universidade Federal do Paraná, durante o inverno de 2008. O objetivo desta pesquisa foi desenvolver modelos de previsão do comportamento do fogo para o planejamento de prevenção e combate aos incêndios florestais. Nos locais preparados paras as queimas foram efetuadas observações e medições sobre o material combustível e variáveis meteorológicas e, durante as queimas, sobre o comportamento do fogo: velocidade de propagação, intensidade do fogo e dimensões da chama. Correlacionando-se os dois grupos de variáveis (do ambiente versus variáveis do comportamento do fogo), obtiveram-se associações significativas entre estas variáveis. Os modelos de regressão desenvolvidos através dos dados coletados produziram estimativas estatisticamente confiáveis do comportamento do fogo em termos de consumo de material combustível, temperatura do ar, umidade relativa e velocidade do vento. Também se verificou que a altura da chama é uma variável fortemente associada à intensidade do fogo, podendo ser empregada para estimativa desta nas condições em que o experimento foi realizado.