bluuebunny/crossref_metadata_2025 huggingface dataset:
First Principles Identification of Divacancy Related Photoluminescence Lines in 4H and 6H-SiC
Authors: Ivády Viktor , Szasz Krisztian , Falk Abram L. , Klimov Paul V. , Janzén Erik , Abrikosov Igor A. , Awschalom David D. , Gali Ádám
Published: May 2016

Nowadays, computational techniques can greatly facilitate the identification of point defect related photoluminescence and EPR centers in semiconductors. Once the identification has been achieved, one can gain a detailed description of the microstructure and the electron configuration of the defect, providing a basis for further understanding and development. Recently, the importance of divacancy and related point defects in different polytypes of SiC has substantially increased due to their possible quantum bit application. However, their different configurations have not been satisfactorily identified yet. In our study, we carry out large-scale first principles supercell calculations to identify the divacancy related point defects in 4H and 6H-SiC. By resolving some general accuracy issues of usual ab initio supercell techniques, we are able to obtain convergent photoluminescence (PL) energies, zero-field-splitting, and hyperfine parameters. Our results confirm the previous assignment of the PL1-4 PL lines in 4H-SiC (also known as UD-2 luminescence lines previously) to the four possible divacancy configurations and provide the identification of QL1,QL2, and QL6 PL lines in 6H-SiC. In all cases the calculated zero-field and hyperfine tensors’ parameters are provided.
Post-Growth Micropipe Formation in 4H-SiC
Authors: Quast Jeffrey , Dudley Michael , Guo Jian Qiu , Hansen Darren , Manning Ian , Mueller Stephan , Raghothamachar Balaji , Sanchez Edward , Whiteley Clinton , Yang Yu
Published: May 2016

Understanding the growth and propagation of defects in SiC remains of interest in an effort to continue to improve device performance. A post-growth boule heat-treatment revealed to form micropipe pairs from apparent single screw dislocations is reviewed. In the treated samples almost no 1c threading screw dislocations were found. Instead, micropipe pairs were observed in similar densities to 1c threading screw dislocations in non-heat treated samples. It is hypothesized that the elevated temperatures allowed for enhanced dislocation mobility, enabling the transition.
Dislocations in SiC Revealed by NaOH Vapor Etching and a Comparison with X-Ray Topography Taken with Various g-Vectors
Authors: Yao Yong Zhao , Ishikawa Yukari , Sugawara Yoshihiro , Sato Koji , Danno Katsunori , Shirai Takayuki , Sato Kazuaki , Bessho Takeshi , Takahashi Yumiko , Yamashita Yoshiki , Hirano Keiichi
Published: May 2016

Threading dislocations (TDs) in 4H-SiC have been studied by comparing etch pits formed by NaOH vapor etching with results of synchrotron monochromatic-beam X-ray topography (XRT) taken under different g-vectors. Burgers vectors determined based on XRT results were utilized to investigate the etch pit characteristics of edge (TED), screw (TSD) and mixed (Burgers vector b=c+a, TMD) threading dislocations. It has been found that pit formation by NaOH vapor etching was very different to that by conventional molten KOH etching. We discuss the possibility of using NaOH vapor etching to distinguish TMDs from TSDs, and report a variety of characteristic etch pits formed by this method and their correlations to dislocation behavior.
Characterization of Threading Screw Dislocations of Burgers Vectors with A-Components in 4H-SiC
Authors: Onda Shoichi , Okamoto Takeshi , Uehigashi Hideyuki , Kondo Hiroyuki , Saka Hiroyasu
Published: May 2016

We characterized threading screw dislocations to investigate the influence on device performance. The Burgers vectors of the threading screw dislocations (a total of 28dislocations) in 4H-SiC were determined by large-angle convergent-beam electron diffraction. A new type of TSD, b=c+2a dislocation was identified. And all of the four types of TSD predicted were identified. The frequency of their occurrence observed experimentally is in good agreement with theoretical prediction. In addition, we investigated relations of Burgers vector and the dislocation line direction.　 It has been confirmed that the Burgers vector of TSD does not necessarily coincide with the direction of dislocation lines. Looking ahead,　we need to investigate how the angle between Burgers vector and dislocation line influence device performance.
Characterization of 4H-SiC PiN Diodes Formed on Defects Identified by PL Imaging
Authors: Bonyadi Yeganeh , Gammon Peter Michael , Bonyadi Roozbeh , Shah Vishal A. , Fisher C.A. , Martin David M. , Mawby Philip  Andrew
Published: May 2016

In this paper the results of a study in which the surface quality of 30, 35 and 110 µm 4H-SiC epitaxial layers from different manufacturers are evaluated using AFM and photoluminescence (PL) imaging. PiN diodes are then intentionally fabricated on triangular defects and polytypes grains which are formed, in order to understand their impact on the resulting electrical characteristics, which includes on-state behaviour, turn-on characteristics and reverse leakage current behaviour. The results indicate that the defects form a high resistance short through the p-type anode. This results in higher leakage current, well over 108 times higher than the devices formed off-defect. PiN diodes fabricated on-defect also suffered from soft breakdown unlike those off-defect.
Cathodoluminescence Study of SiO2/4H-SiC Structures Treated with High-Temperature Post-Oxidation Annealing
Authors: Chanthaphan Atthawut , Fukushima Yuta , Yamamoto Kenji , Aketa Masatoshi , Asahara Hirokazu , Nakamura Takashi , Hosoi Takuji , Shimura Takayoshi , Watanabe Heiji
Published: May 2016

The radiative defect centers in thermally-grown SiO2/4H-SiC structures with high-temperature post-oxidation annealing (POA) in various ambient gas, i.e. Ar, H2, and NOx, were examined using cathodoluminescence (CL) measurement. It was found that radiative centers with an extremely high luminescent efficiency were remained at the SiO2/SiC interfaces after Ar-POA and FGA. Thus, these defect centers are very stable against high-temperature annealing and reducing ambient. In contrast, NOx-POA significantly reduced amounts of the radiative defects that might be related to channel mobility improvement in SiC-MOSFETs.
Characterization of Thermally Oxidized SiO2/SiC Interfaces by Leakage Current under High Electric Field, Cathode Luminescence (CL), X-Ray Photoelectron Spectroscopy (XPS) and High-Resolution Rutherford Backscattering Spectroscopy (HR-RBS)
Authors: Kiuchi Yuji , Kitai Hidenori , Shiomi Hiromu , Tsujimura Masatoshi , Nakata Daisuke , Harada Shinsuke , Yonezawa Yoshiyuki , Fukuda Kenji , Sakamoto Kunihiro , Yamasaki Kimiyoshi , Yano Hiroshi , Okumura Hajime
Published: May 2016

Wet and N2O oxidized SiO2/SiC for C-face substrates were comprehensively investigated to clarify the origin of oxide defects which affect channel mobility and threshold voltage stability by using leakage-current analysis. The estimated defects are identified by cathode luminescence, X-ray photoelectron spectroscopy, and high-resolution Rutherford backscattering spectroscopy. The origin of the observed oxide defects might be complex defect of O vacancy defects and/or C related defects including N.
Importance of SiC Stacking to Interlayer States at the SiC/SiO2 Interface
Authors: Kirkham Christopher James , Ono Tomoya
Published: May 2016

We investigated the effect of SiC stacking on the 4H-SiC/SiO2 interface via first principles calculations. Interlayer states are observed along the SiC conduction band edge, and are affected by the local structure at the interface. The location of these states changes depending on which of two lattice sites, h or k is at the interface. This difference is important for SiC based metal-oxide-semiconductor field-effect transistors which rely on the electronic structure of the conduction band.
On the Origin of Threshold Voltage Instability under Operating Conditions of 4H-SiC n-Channel MOSFETs
Authors: Pobegen Gregor , Weisse Julietta , Hauck Martin , Weber Heiko B. , Krieger M.
Published: May 2016

We report on the threshold voltage () instability under operating conditions after gate bias switches at constant drain voltage for n-MOSFETs fabricated on 4H silicon carbide (4H-SiC). This effect occurs at room temperature and close to the of the device. We show that the origin of the instability is electron trapping into SiO2 over an energy barrier of (0.3-0.4) eV. These traps show similarities to traps previously observed in 4H-SiC MOS capacitors and labelled near interface traps (NITs). Further, the density of the traps can be reduced by one order of magnitude through post-oxidation annealing in nitric oxide atmosphere.
Junction Barrier Schottky (JBS) Rectifier Interface Engineering Facilitated by Two-Dimensional (2D) Dopant Imaging
Authors: ROSSMANN Harald , Gysin Urs , Bubendorf Alexander , Glatzel Thilo , Reshanov Sergey A. , Zhang A. , Schöner Adolf , Jung T.A. , Meyer Ernst , Bartolf Holger
Published: May 2016

The shielding cell architecture of a buried grid (BG) Junction Barrier Schottky (JBS) diode consisting of multiple consecutive p+-implanted stripes below the metal/semiconductor interface has been observed by performing non-contact Scanning Probe Microscopy (SPM) and Secondary Electron Potential Contrast (SEPC) measurements on the cross-section of the device. We have demonstrated that these techniques succeeded in mapping the two-dimensional carrier distribution inside the active area of the device, however with different resolution and quantification possibilities.
Spatial Distribution of Carrier Concentration in 4H-SiС Crystal Grown by Solution Method
Authors: Wang Zhen Jiang , Kawaguchi Takahiko , Murayama Kenta , Aoyagi Kenta , Harada Shunta , Tagawa Miho , Sakai Takenobu , Kato Tomohisa , Ujihara Toru
Published: May 2016

We investigated the spatial distribution of carrier concentration in n-type 4H-SiC grown by the solution method from the peak frequency of the longitudinal optical phonon-plasmon coupled (LOPC) mode of the Raman spectra on the surface. The carrier concentration at the position of the smooth terrace was higher than the carrier concentration at the position where the macrosteps were formed. This indicates the nitrogen incorporation efficiently occurs on the smooth surface where the density of macrosteps is relatively low. The different incorporation of nitrogen depending on the surface morphology can be understood from the view point of the adsorption time of impurity on the terrace. The present result implies that the uniform surface morphology is necessary to achieve uniform doping concentration in SiC crystal.
Novel 3C-SiC Microstructure for MEMS Applications
Authors: Michaud Jean François , Portail Marc , Khazaka Rami , Zielinski Marcin , Chassagne Thierry , Alquier Daniel
Published: May 2016

The aim of this paper is to review the recent developments conducted for the achievement of 3C-SiC‑based heterostructures compatible with MEMS applications. Indeed, the research activities engaged since years permitted to demonstrate that the defect density has an impact towards the Young’s modulus of sub-micron 3C‑SiC epilayers. We also gained knowledge about the stress relaxation mechanisms, targeting to master the stress gradient, as stress is a key parameter to consider MEMS applications.Based on these results, we investigated the elaboration of microstructures using 3C‑SiC/Si/3C‑SiC stacks on silicon substrates. Our first noticeable result was the elaboration of a (110)-oriented 3C‑SiC membrane on a 3C‑SiC pseudo-substrate, using the silicon epilayer as a sacrificial one. But the surface of the 3C‑SiC membrane was facetted and rough, which could hamper its use for the development of new MEMS devices. Then, with further improvements, we succeeded to master the growth of a (111)‑oriented 3C‑SiC epilayer. This feature led to a drastic reduction of the roughness in comparison with the (110) orientation. Actually, using the same experimental protocol than previously, we succeeded to complete a (111)‑oriented 3C‑SiC membrane with a RMS roughness limited to 9nm. Such an optimized structure could be the starting point for the achievement of new MEMS devices operating in harsh environment or for medical applications benefiting of the 3C‑SiC biocompatibility
Anomalous Scatter of Forward Current-Voltage Characteristics of He+-Irradiated Ni/4H-SiC Schottky Diodes
Authors: Strel'chuk Anatoly M. , Zelenin Viktor V. , Kuznetsov Alexei N. , Tringe Joseph , Davydov Albert V. , Lebedev Alexander A.
Published: May 2016

A study of forward current-voltage characteristics of Ni/4H-SiC Schottky diodes (SDs) before and after irradiation with He+ ions revealed features that characterize defect structures and reveal the degradation mechanism of the diodes. These features are the presence of excess currents of certain type in the unirradiated SDs, their appearance in forward-biased originally ideal SDs, and a >10 orders of magnitude scatter of the series resistance of the SDs upon their irradiation with He+ ions. A model of localized defect-induced current paths (shunts) in the form of unintentionally produced SDs with the substrate is suggested.
Short Circuit Robustness of 1200 V SiC Junction Transistors and Power MOSFETs
Authors: Sundaresan Siddarth G. , Grummel Brian , Singh Ranbir
Published: May 2016

Short-circuit (SC) robustness of 1200 V-rated SiC npn Junction Transistors (SJTs) and commercial power DMOSFETs is investigated. Due to low (2x) overdrive base currents and low short-circuit currents, SJTs demonstrate superior SC capability including: (a) minimum short-circuit withstand time (tSC) of 14 µs, even at VDS=1000 V (b) Perfectly stable output and blocking characteristics after 10,000, 10 µs long SC pulses at 800 V, (c) tSC ≥ 18 µs at 800 V up to (at-least) 175°C base-plate temperatures. In contrast, commercial (Gen-II) 1200 V/80 mΩ SiC MOSFETs exhibit catastrophic failure beyond tSC = 7 µs at 500 V, and tSC = 3 µs at 800 V, due to excessive SC currents of > 200 A resulting in junction temperatures in excess of 650°C. The MOSFET’s drain leakage current increases by a factor of 120, and the VTH reduces by 20%, after 7 µs-long SC pulses at 500 V.
The Influence of Surface Pit Shape on 4H-SiC MOSFETs Reliability under High Temperature Bias Tests
Authors: Uchida Kosuke , Hiyoshi Toru , Nishiguchi Taro , Yamamoto Hirofumi , Matsukawa Shinji , Furumai Masaki , Mikamura Yasuki
Published: May 2016

The influence of surface pit shape on 4H-SiC double implanted MOSFETs (DMOSFETs) reliability under a high temperature drain bias test has been investigated. Threading dislocations formed two types of pit shapes (deep pit and shallow pit) on an epitaxial layer surface. The cause of the failure was revealed to be an oxide breakdown above the pit generated at the threading mixed dislocation in both pit shapes. Weibull distributions between two types of pits were different. Although the DMOSFETs on the epitaxial layer with the deep pit show longer lifetime than those with the shallow pit, the epitaxial layer with the shallow pit is suitable to estimate the lifetime of the DMOSFETs because of a linearity of the Weibull plot. The lifetime of the DMOSFETs with the shallow pit was dominated by an oxide electric field. The maximum oxide electric field required to obtain the lifetime of more than 10 years was estimated to be 2.7 MV/cm.
Si/SiC Substrates for the Implementation of Linear-Doped Power LDMOS Studied with Device Simulation
Authors: Chan Chun W. , Bonyadi Yeganeh , Mawby Philip  Andrew , Gammon Peter Michael
Published: May 2016

In this study, a 600 V LDMOSFET using a silicon-on-silicon carbide (Si/SiC) substrate is presented. An SOI counterpart is established with a linear-doped drift region the same as that of the Si/SiC transistor. Simulation results show that they perform similar off-state behaviours, both with a significant tunneling leakage emerging above 450 V at 300 K. In the on-state, the proposed structure has advantages over the SOI, namely lower resistance, higher saturation current and improved self-heating effect. Turn-off performance is also enhanced owing to substantial reduction of the drain-substrate capacitance. These are realised by an “IOS” (Insulator on Silicon) setup embedded in the Si/SiC structure.
Characterization of 4H-SiC nMOSFETs in Harsh Environments, High-Temperature and High Gamma-Ray Radiation
Authors: Kuroki Shin Ichiro , Nagatsuma Hirofumi , De Silva Wijemuni , Ishikawa Seiji , Maeda Tomonori , Sezaki Hiroshi , Kikkawa Takamaro , Makino Takahiro , Ohshima Takeshi , Östling Mikael , Zetterling Carl Mikael
Published: May 2016

Characteristics of 4H-SiC nMOSFETs with arsenic-doped S/D and NbNi silicide contacts in harsh environments of high-temperature up to 450°C, and high gamma-ray radiation up to over 100 Mrad, were investigated. At high temperature, field effect mobility increased as proportional to T3/2, and threshold voltage was shifted with temperature coefficients of -4.3 mV/K and -2.6 mV/K for oxide thicknesses of 10 nm and 20 nm, respectively. After Co60 gamma-ray exposure of 113 Mrad, the field effect mobility was varied within 8% for oxide thickness of 10 nm, however for 20 nm oxide thickness, this variation was 26%. The threshold voltage shifts were within 6%.
Gamma-Ray Irradiation Response of the Motor-Driver Circuit with SiC MOSFETs
Authors: Kobayashi Yugo , Yokozeki Takashi , Matsuda Takuma , Mitomo Satoshi , Murata Koichi , Hachisuka Michihiro , Kaneko Yasuyoshi , Makino Takahiro , Takeyama Akinori , Onoda Shinobu , Ohshima Takeshi , Tanaka Yuki , Kandori Mikio , Yoshie Toru , Hijikata Yasuto
Published: May 2016

Gamma-ray irradiation effects of motor-driver circuit composed of SiC MOSFETs under motor driving with different PWM frequencies were investigated. The driving current and voltage waveforms were normal when the irradiation exceeded 1.1 MGy at PWM frequency of 10 kHz. In addition, the motor was still rotating in this total dose. We compared the irradiation responses of SiC MOSFETs between the cases of driving states and no bias. The drain current – gate voltage characteristics with no bias shifted to the negative voltage side wider than the driving states. Also the leakage current in the case of driving state is fewer than that of no bias.
Avalanche Capabilities of Commercial 1200 V 4H-SiC Power MOSFETs
Authors: Di Marino Christina , Hull Brett
Published: May 2016

Avalanche testing is a common method for evaluating the ruggedness of switching devices. Typically, datasheets specify an avalanche rating under a single operating condition. Instead, in this work, 1.2 kV, 24 A SiC MOSFETs are subjected to avalanche events under a variety of conditions. From this testing, a curve is drawn which shows the area for safe avalanche operation. Post-characterization and high temperature reverse bias testing were performed to ensure that the avalanche events did not degrade the device performance or lifetime. CoolMOS devices were also tested for comparison, and, unlike the SiC MOSFETs, the Si devices showed a notable decrease in avalanche capability as the current in avalanche was increased. The SiC MOSFETs were able to endure one hundred single avalanche events at 20 A and 1000 mJ without any sign of lifetime degradation.
Electrical Characterization of 1.2 kV-Class SiC MOSFET at High Temperature up to 380°C
Authors: Nanen Yuichiro , Aketa Masatoshi , Nakano Yuki , Asahara Hirokazu , Nakamura Takashi
Published: May 2016

Dynamic and static characteristics of SiC power MOSFETs at high temperature up to 380°C were investigated. Investigated devices have exhibited a behavior as a normally-off MOSFET even at such high temperature as 380°C. Temperature dependence of the MOSFET characteristics are reported in this paper, such as threshold voltage (VTH), on-resistance, internal gate resistance, and turn-on and turn-off losses (EON, EOFF). EON decreases and EOFF increases with increased temperature. Temperature dependence of switching losses is affected by transfer time of VDS, which was mainly determined from VTH.
Physical Vapor Growth of Double Position Boundary Free, Quasi-Bulk 3C-SiC on High Quality 3C-SiC on Si CVD Templates
Authors: Schuh Philipp , Vecera Philipp , Hirsch Andreas , Syväjärvi Mikael , Litrico Grazia , La Via Francesco , Mauceri Marco , Wellmann Peter J.
Published: May 2016

We have developed and investigated the quasi-bulk crystal growth of 3C-SiC on transferred, high quality, CVD-grown templates using a sublimation sandwich related technique. The seeding layers were removed from the silicon carrier using a solution of hydrogen fluoride, nitric acid and water and glued to a substrate using carbon glue. The transferred layers were used as seeding material to grow high quality, single crystalline, DPBs free 3C-SiC crystals with thicknesses of up to 860 μm and a size of 18 x 20 mm. Analysis of the 3C-SiC layers was carried out using Laue measurement in back-reflecting geometry, Raman spectroscopy and optical microscopy.
Conduction Loss Reduction for Bipolar Injection Field-Effect-Transistors (BIFET)
Authors: Hürner Andreas , Mitlehner Heinz , Erlbacher Tobias , Bauer Anton J. , Frey Lothar
Published: May 2016

In this study, the potential of forward conduction loss reduction of Bipolar-Injection Field-Effect-Transistors (SiC-p-BIFET) with an intended blocking voltage of 10kV by adjusting the doping concentration in the channel-region is analyzed. For the optimization of the SiC-p-BIFET, numerical simulations were carried out. Regarding a desired turn-off voltage of approximately 25V, the optimum doping concentration in the channel-region was found to be 1.4x1017cm-3. Based on these results, SiC-p-BIFETs were fabricated and electrically characterized in the temperature range from 25°C up to 175°C. In this study, the differential on-resistance was found to be 110mΩcm2 for a temperature of 25°C and 55mΩcm2 for a temperature of 175°C. In comparison to our former results, a reduction of the differential on-resistance of about 310mΩcm2 at room temperature is demonstrated.
An Analysis of Forward Conduction Characteristics of Ultra High Voltage 4H-SiC N-IGBTs
Authors: Ryu Sei Hyung , Capell Craig , Jonas Charlotte , O’Loughlin Michael , Clayton Jack , Lam Khiem , van Brunt Edward , Lemma Yemane , Richmond Jim , Grider David , Allen Scott , Palmour John W.
Published: May 2016

Ultra High Voltage (UHV) 4H-SiC N-IGBTs, with drift layer thicknesses ranging from 140 μm to 240 μm, were fabricated and characterized. A blocking voltage of 25 kV, and a forward voltage drop (VF) of 12.8 V were measured from a 9 mm x 9 mm device with a 240 μm drift layer. A positive temperature coefficient of VF was observed, which is desirable for paralleling, but unusual for a bipolar device. The cause of this behavior was investigated using a test structure that allowed separate observations of electron and hole currents in the 4H-SiC IGBT structure. It was revealed that the hole current increases with temperature, due to increases in charge injection and carrier lifetimes at elevated temperatures, while the electron current decreases with temperature due to a unipolar resistance component in its path, most likely due to JFET resistance, formed by depletion regions extending into the lightly doped drift region. The concept of Carrier Storage Layer (CSL) was implemented in UHV 4H-SiC N-IGBTs to suppress this effect, resulting in a negative temperature coefficient of VF. A 15 kV 4H-SiC N-IGBT with a 1x1016cm-3 doped CSL showed a VF reduction of 3 V at a collector current of 20 A, at a junction temperature of 150°C, compared to a 15 kV SiC N-IGBT without a CSL at the same collector current value.
Effect of Platinum Particle Size and Oxygen Pressure on Activity of Platinum/Carbon Gas Diffusion Electrodes in High Temperature Acid Medium
Authors: Tang Jing , Meng Hui Min , Liang Xuan
Published: May 2016

The Platinum/Carbon (Pt/C) gas diffusion electrode was used as cathode instead of the traditional electrode for energy saving electrodeposition of manganese dioxide (MnO2). This paper studies Pt particle size and oxygen pressure (PO2) effect on activity of Pt/C gas diffusion electrodes in high temperature acid medium. The Pt nanoparticles evenly distributed on the carbon black surface except the Pt/C-4 and the diameters of the Pt particles size are different (Pt/C-1, Pt/C-2, Pt/C-3, Pt/C-4). The particle sizes of the Pt/C-1, Pt/C-2, Pt/C-3, Pt/C-4 are about 1.6 nm, 2.02 nm, 3.0 nm and 9 nm, respectively. When the loading amount of Pt is the same, the electrode performance of the Pt/C-3 gas-diffusion cathode is better than that of the Pt/C-1, Pt/C-2 and Pt/C-4 gas-diffusion cathode. The open circuit potential, oxygen reduction current of the Pt/C gas diffusion electrode increase with increasing oxygen pressure.
Morphology and Mechanical Property of Compressible Graphene Aerogel
Authors: Wu Bin , Chen Ri Ming , Jin Jun Hong , Li Guang
Published: May 2016

Compressible graphene aerogel (CGA) was prepared via one-step reduction and self-assembly of graphene oxide with urea as reducing agent and then freeze-drying. The morphology and mechanical property of CGA were characterized by scanning electron microscope (SEM) and mechanical testing. The results revealed 3D honeycomb-shaped porous structure was built and ultra-light CGA with density of 6.3 mg·cm-3 was achieved. The CGAs showed exceptional compression performance, which could be compressed to more than 50% of its own height and recover to original state immediately after released. The maximum stress reached to 8.1kPa with 50% strain and decreased quite little after compression up to 100 cycles.
A Multistep Scheme for Decoupled Forward-Backward Stochastic Differential Equations
Authors: Zhao Weidong , Zhang Wei , Ju Lili
Published: May 2016

Upon a set of backward orthogonal polynomials, we propose a novel multi-step numerical scheme for solving the decoupled forward-backward stochastic differential equations (FBSDEs). Under Lipschtiz conditions on the coefficients of the FBSDEs, we first get a general error estimate result which implies zero-stability of the proposed scheme, and then we further prove that the convergence rate of the scheme can be of high order for Markovian FBSDEs. Some numerical experiments are presented to demonstrate the accuracy of the proposed multi-step scheme and to numerically verify the theoretical results.
Sensory Features of Toddlers at Risk for Autism Spectrum Disorder
Authors: Philpott-Robinson Kelsey , Lane Alison E. , Harpster Karen
Published: May 2016

OBJECTIVE. We observed sensory features in toddlers ages 12–24 mo with risk factors for autism spectrum disorder (ASD) and explored their relationship to general development and early signs of ASD.

METHOD. Participants (N = 46) included toddlers with higher risk for ASD. All participants were administered standardized assessments of sensory features, early signs of ASD, and general development at a single study visit.

RESULTS. Sensory features in toddlers were characterized as either adaptive or reactive. Toddlers with more difficulties in oral sensory processing displayed more early signs of ASD. Typical oral and auditory processing were associated with higher cognitive function, and toddlers with fewer sensory features overall had more mature language skills.

CONCLUSION. Specific sensory features were associated with both early signs of ASD and less mature general development. Replication of this preliminary study is required.
Psicodrama: cuerpo, espacio y tiempo hacia la libertad creadora
Authors: Severino Gabriela , Silva Walter Sergio , Silva Severino Mª Florencia
Published: May 2016

El Psicodrama, creado por Jacob Levy Moreno, es un método de abordaje del individuo, la familia, los grupos y la comunidad, que tuvo sus orígenes en el teatro, la sociología y la psicología. Desde su trabajo con niños y grupos marginales, su creador va gestando su teoría y su técnica. Se desarrolla en diferentes ámbitos: clínica, psicoterapia, pedagogía y comunidad. El cuerpo, el juego, el espacio y el tiempo confluyen de una manera poética y contribuyen a la libertad creadora y a la tan añorada espontaneidad. El Psicodrama se desarrolla en ese espacio transicional, que no siendo ni interno, ni externo, se transforma en ese espacio pluripotencial de infinitas posibilidades creadoras.
Musicoterapia y Arteterapia. Puntos de encuentro en el camino terapéutico
Authors: Pérez Eizaguirre Miren , Fernández Compañ José Fernando
Published: May 2016

En este artículo pretendemos buscar los aspectos que confluyen en el ámbito de la musicoterapia y el arteterapia, comenzando por su definición y orígenes y siguiendo con los modelos teóricos más importantes. Al analizar los trabajos de investigación elaborados a partir de proyectos en los que se combina la práctica de las dos disciplinas, observamos la necesidad de una mayor interdisciplinareidad. Esto daría lugar a un mayor enriquecimiento de las sesiones y por tanto, del trabajo terapéutico, lo que revertiría en una mejora de la calidad de la intervención.
Sobre el acompañamiento en Arteterapia
Authors: Serrano Navarro Ana
Published: May 2016

En el presente artículo comparto algunas reflexiones a partir del relato del caso de un menor, diagnosticado de trastorno de apego reactivo, con el que trabajé a través del arteterapia desde los 11 a los 13 años en el marco de un Hospital de Día. Me sirven tales reflexiones en un intento por ahondar en algunos elementos específicos de la disciplina que nos ayuden a delimitar su posible alcance teórico y metodológico. Así, desde lo particular del caso se propone reflexionar sobre aquellos elementos que van constituyendo una metodología en el hacer del arteterapeuta y que permiten concretar y evaluar posibles intervenciones a desarrollar con otros casos y contextos similares.
Indicadores sobre prácticas artísticas comunitarias: algunas reflexiones
Authors: López Fdz.Cao Marián
Published: May 2016

A partir del proyecto Divercity, se ha reflexionado sobre la metodología, las buneas prácticas y los indicadores útiles para las prácticas artísticas comunitarias. En un primer término, se define qué se considera como “exclusión social”, qué es el arte comunitario, qué carácterísticas presenta. Posteriormente, el artículo revisa los indicadores que se están utilizando para medir el éxito o grado de consecución de los mismos, planteando críticas desde la igualdad e incluyendo indicadores que midan el bienestar de las mujeres.
Valorization of cultural diversity throught Good Practices Dissemination on Art Mediation: sharing experiencies
Authors: Semova Dimitrina J.
Published: May 2016

In this article, as part of the Erasmus+ project “Divercity”, we focus on the collection and analysis of good practices in Spain and other countries in Europe. The project revolves around the development of methods that valorize cultural diversity and in this respect, identifying and sharing best practices on diversity and inclusion through artistic mediation inside museums, culture institutions, our urban walks, forms an mandatory stage of the research process.
Circus Workshop in the chid Psychiatry
Authors: Dora Crusös
Published: May 2016

The following paper is about the possible psychological effects of social circus, and our experiences with teaching circus methods in children psychiatry. In the beginning the paper try to place social circus in a wider theoretical frame, and searches for the place of it among psychological methods and therapies. We look at the wider and the more specific psychological constructs, what can be effected by social circus, especially the factors which are damaged in children with psycological or psychiatrycal problems. We examine the different parts of circus, how they can help in different problems. The further aim is to research the effects of a continuous social circus group, and to find it’s own way among psychotherapies.
Sosialhjelpsmottakeres dødelighet: I hvilken grad kan overdødeligheten tilskrives deres sosiale status?
Authors: Naper Sille Ohrem , Dahl Espen
Published: May 2016

I denne artikkelen undersøker vi dødelighet blant sosialhjelpsmottakere i Norge, som sammenlignes med dødeligheten i resten av befolkningen, og om en antatt overdødelighet kan forklares ved sosiale forhold som kjennetegner dem som har status som sosialhjelpsmottakerne, og som har betydning for dødelighetsnivå. Data er hentet fra FD-trygd og omfatter hele den norske befolkningen i aldersgruppen 18-57 år i 1992. Vi analyserer dødeligheten fra 1994 til 2003. Sosialhjelpsmottakere er definert som personer som mottok sosialhjelp i 1993 (N=146 176), og det skilles mellom korttids- og langtidsmottakere (≥ 6 måneder). Menn og kvinner behandles separat. En serie multiple Cox regresjonsmodeller er estimert for å belyse problemstillingene. Den enkleste modellen, som kun inneholder sosialhjelp og alder, viser at dødeligheten til sosialhjelpsmottakere er langt høyere enn andres. Hasardratioene (HR) for mannlige kortidsmottakere av sosialhjelp sammenlignet med befolkningen er 3,5 (95% KI = 3,34-3,62), for langtidsmottakere 4,8 (4,64-5,01). For kvinner er HR henholdsvis 2,8 (2,60-2,93) og 3,9 (3,66-4,15). Overdødeligheten blant sosialhjelpsmottakere reduseres ettersom forklaringsvariablene introduseres. I den fulle modellen, som inneholder alder, sivilstand, utdanning, inntekt og uførepensjon, er HR for kvinner redusert med 60 prosent for korttidsmottakere, og 50 prosent for langtidsmottakere, noe mindre for menn. HR er fortsatt høye i de justerte modellene, særlig for langtidsmottakere av sosialhjelp. De er nå for menn, korttid: 2,1 (1,98-2,15) og langtid: 3,1 (2,98-3,23), kvinner, korttid: 1,7 (1,61-1,82) og langtid: 2,5 (2,29-2,62). I lys av tidligere forskning på feltet argumenter vi for at et livsløpsperspektiv er fruktbart for å forstå sosialhjelpsmottakeres overdødelighet. Samtidig peker vi på flere trekk ved posisjonen som sosialhjelpsmottaker som kan være helseskadelig
Kan lokalbaserte strategier bidra til å redusere sosiale helseforskjeller? MoRo-prosjektet – bakgrunn, hovedresultater og erfaringer
Authors: Jenum Anne Karen , Lorentzen Catherine , Graff-Iversen Sidsel , Andersen Sigmund , Ødegaard Ann Kristin , Holme Ingar , Birkeland Kåre , Ommundsen Yngvar
Published: May 2016

I en multietnisk bydel i Oslo med høy dødelighet og lav sosioøkonomisk status ble en teoribasert befolkningsrettet intervensjon for å fremme fysisk aktivitet utviklet og evaluert. Alle i alderen 31-67 år i intervensjonsbydelen og et aldersmatchet utvalg i kontrollbydelen ble invitert til en helseundersøkelse i 2000, og 2950 (48%) møtte. Store etniske forskjeller i diabetesforekomst ble funnet. I aldersgruppen 30-59 år var forekomsten hos sør-asiatiske kvinner 27,5% (95% KI 18,1-36,9) og hos menn 14,3% (8,0-20,7), mot 2,9% (1,9-3,9) hos norske kvinner og 5,9% (4,2-7,5) hos menn. De etniske forskjellene var signifikante etter justering for alder, midje/hofteratio, fysisk aktivitet og utdanning. Etter ytterligere justering for kroppshøyde var OR for kvinner (også justert for paritet) 6,0 (2,3-15,4) og for menn 1,9 (0,9-4,0). En sterk invers assosiasjon mellom diabetes og utdanning og inntekt ble funnet hos de vestlige. Hos innvandrere ga økt inntekt økt risiko for diabetes. Etter intervensjonen møtte 67% til oppfølgingsundersøkelsen i 2003. Endringer i fysisk aktivitet, dagligrøyking og biologiske variabler ble beregnet hos dem som møtte begge ganger. Netto økning i fysisk aktivitet (forskjell i endring fra 2000-2003 mellom bydelene) var 9,5% (p=0,008). Andel inaktive ble redusert med 22%. Andelen som gikk opp i vekt, ble redusert med 50% i forhold til kontrollbydelen (p
Fødsler i førti år
Authors: Lie Rolv T. , Kristensen Petter
Published: May 2016

Fødsel er et grunnleggende positivt uttrykk for livskraft og ny begynnelse. I vårt språk brukes fødsel som synonym for tilblivelse i mange sammenhenger. Men uttrykket følges ofte av en liten skygge av smerte eller belastning. Dette nummeret markerer at Medisinsk fødselsregister har registrert alle fødsler i Norge i førti år og hva dette har avfødt av viktig forskning og kunnskap. Nummeret markerer også at Lorentz Irgens går av som mangeårig leder ved registeret
Det nye pasientregisteret kan redde liv
Authors: Stoltenberg Camilla
Published: May 2016

Første juli 2007 ble Helseregisterloven endret og Norsk pasientregister (NPR) blir personidentifiserbart uten samtykke. Dette er en milepæl i den lange historien om forsøkene på å etablere et sykdoms- og skaderegister i Norge.
The Norwegian Mother and Child Cohort Study (MoBa) – new research possibilities
Authors: Magnus Per
Published: May 2016

The Norwegian Mother and Child Cohort Study (MoBa) is an observational, prospective study of up to 100 000 families. The study aims to find causes of diseases, with a focus on the interplay between early exposures and genetic factors. The collection of possible exposures starts in pregnancy. As of September 2007, about 80 000 families participate. A series of subprojects are ongoing, and analyses and publications are on their way. This paper presents the present situation of MoBa, and highlights new challenges and opportunities.
B-vitaminet folat og svangerskap
Authors: Vollset Stein Emil , Nilsen Roy M. , Daltveit Anne Kjersti
Published: May 2016

Foreldre redder mer enn 100 spedbarn hvert år i Norge fordi de lar dem sove på ryggen. Medisinsk fødselsregister har vært sentral i å vise at krybbedød økte allerede på slutten av 1970-tallet, at økningen skyldtes den populære sovestillingen mageleie, at ryggleie hindrer krybbedød, og at vi fortsatt må overvåke hyppigheten av krybbedød og forekomsten av risikofaktorene i spedbarnspopulasjonen. Epidemiologiske studier danner det viktigste bevisgrunnlaget for årsaken til krybbedød
The potential use of Apgar score and neonatal encephalopathy in registry based studies
Authors: Moster Dag , Markestad Trond
Published: May 2016

We have previously described the impact of Apgar scores on later major and minor disabilities. According to these and other studies, children with low Apgar scores have to show symptoms of neonatal encephalopathy in the first week of life to be at risk of developing later disabilities. Information on neonatal encephalopathy has traditionally been less accessible than Apgar scores in The Medical Birth Registry of Norway (MBRN). In the present study the possibility of extracting information on neonatal encephalopathy from the new notification form to the MBRN, which was introduced in late 1998, was investigated. The introduction of specific and generally accepted definitions of neonatal diagnoses combined with more comprehensive reports to MBRN from the neonatal departments may render registry based studies on neonatal encephalopathy possible in the future
SUPLEMENTOS NUTRICIONAIS
Authors: Costa Tatiana Munhoz da Rocha Lemos , Borba Victória Zeghbi Cochenski
Published: May 2016

A promessa de resultados rápidos e milagrosos no ganho de massa muscular, definição corporal, redução de gordura e peso corporal vem contribuindo para o uso abusivo de suplementos nutricionais. Porém, previamente à indicação de qualquer suplementação, faz-se necessária uma orientação dietética adequada. A ingestão da quantidade correta de calorias, carboidratos, proteínas, gorduras, vitaminas e minerais é a base fundamental para qualquer praticante de atividade física. E a suplementação primária deve ocorrer quando não se consegue suprir a necessidade diária dos nutrientes através da alimentação. Já foram descritos mais de duzentos e cinquenta tipos de suplementos alimentares. Os suplementos podem conter carboidratos, proteínas, gorduras, minerais, vitaminas, ervas, enzimas, substâncias do metabolismo intermediário (como aminoácidos) e vários tipos de extratos vegetais e animais. Este artigo é uma revisão sobre os suplementos nutricionais que apresentam embasamentos científicos consistentes: carboidratos, proteínas, BCAAs (Aminoácidos de Cadeia Ramificada) e creatina. O intuito é de prover um esclarecimento e orientar a população médica quanto à indicação, benefícios e riscos dessas substâncias.
USO DA DIÁLISE PROLONGADA DE BAIXA EFICIÊNCIA EM PACIENTES DO HOSPITAL DE CLÍNICAS-UFPR
Authors: Chornobay Ana Paula , Braga Ariane Coutinho , Sevignani Gabriela , Hocama Nathalia , Chula Domingos Candiota , Nascimento Marcelo Mazza
Published: May 2016

Introdução: A Diálise Prolongada de Baixa Eficiência (DPBE), terapia híbrida de substituição da função renal, surgiu como alternativa aos métodos intermitentes e contínuos de diálise na insuficiência renal aguda. Objetivo: Demonstrar a experiência com a DPBE no tratamento de pacientes da Unidade de Terapia Intensiva (UTI) e do Centro de Terapia Semi-Intensiva (CTSI) do Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR) entre Abril/2013 e Outubro/2014. Materiais e Métodos: As informações foram coletadas dos prontuários de pacientes da UTI/CTSI, submetidos à DPBE (sistema GENIUS®) com duração de 8 horas. Incluíram-se dados demográficos como: sexo, idade, presença de diabetes mellitus (DM), hipertensão arterial sistêmica (HAS) e doença renal crônica (DRC), uso de drogas vasoativas (DVA) e de ventilação mecânica (VM). Foram obtidas dosagens plasmáticas de ureia, creatinina, sódio, potássio, fósforo, magnésio, bicarbonato, glicose, saturação de O2 e pressão parcial de O2 e de CO2 em três momentos: antes, na 4ª hora e após o procedimento (8ª hora). Resultados: 41 DPBE foram realizadas em 17 pacientes, 8 mulheres. 88% estavam em VM e DVA. A taxa de mortalidade no internamento foi de 76%. 35% apresentavam DM, quase 60%, HAS, e em torno de 17%, DRC. O percentual médio de redução de ureia (%) foi de 62 ± 8,4. O fósforo (mg/dL) reduziu significativamente entre primeira (4,09l ± 2,28) e oitava horas (2,03 ± 1,04), p<0,05. Conclusão: A DPBE demonstrou-se efetiva e segura em relação à diálise convencional, havendo necessidade de reposição de fósforo durante o tratamento devido à hipofosfatemia observada na maioria dos casos.
BRONQUIOLITE OBLITERANTE E PNEUMONIA EM ORGANIZAÇÃO SECUNDÁRIA AO USO DE AMIODARONA
Authors: Pereira da Cunha João Pedro , Frandoloso Gibran Avelino , Cervi Lagana Caio Cesar , Pupo Melissa
Published: May 2016

A amiodarona é um antiarrítmico comumente utilizado na prática clínica e pode estar associado a diversos efeitos adversos, muitos deles com significativa morbimortalidade, como o acometimento pulmonar. O presente caso descreve uma mulher de 63 anos com toxicidade pulmonar aguda pela amiodarona, utilizada em curto período de tempo. A realização de biópsia pulmonar demonstrou bronquiolite obliterante e pneumonia em organização (BOOP). Após interrupção do uso do antiarrítmico e o início da corticoterapia, a paciente obteve expressiva melhora clínica e radiológica.
ANÁLISE DA ALTURA DO SORO NO FLUXO DE SAÍDA DE EQUIPO USADO PARA ARTROSCOPIA
Authors: Ziesemer Costa Isabel , Ribas Carmem Australia Paredes Marcondes , Namba Mário Massatomo , Bauer Luiz Antonio de Ridder , Franco Ana Paula Gebert de Oliveira , Stieven Filho Edmar
Published: May 2016

Objetivo: Este trabalho tem como objetivo analisar a influência da altura das bolsas de soro no fluxo de saída, ou vazão, do fluido através de um equipo quatro vias acoplado a uma camisa e ótica artroscópica. Métodos: Foi analisado o tempo de escoamento do soro fisiológico 0,9% por um equipo quatro vias, acoplado em uma camisa e ótica artroscópica, para atingir os volumes de 2000 mL e 4000 mL. Foram realizados 20 testes experimentais, divididos em dois grupos: Grupo 1- suporte elevado a uma altura de 80 cm, Grupo 2- suporte elevado a uma altura de 150 cm. Resultados: O fluxo médio nos testes realizados com as bolsas de soro a 80 cm foi de 7,78 cm3/s no período de tempo decorrido até o escoamento de 2000 mL e 6,82 cm3/s para 4000 mL. Com a elevação das bolsas de soro até 150 cm o fluxo médio foi para 12,11 cm3/s durante o período de enchimento dos 2000 mL e 10,59 cm3/s para 4000 mL. Conclusão: O aumento da altura das bolsas de soro de 80 cm para 150 cm gerou um aumento de 60% na vazão do soro fisiológico.
DO EDITOR
Authors: Carvalho Mauricio
Published: May 2016

Duas publicações referente às escolas de Medicina no Brasil chamaram a atenção nestes últimos dias.Primeiramente, de 2003 a 2015, o número de escolas médicas saltou de 126 para 257, sendo que as particulares pularam de 64 para 154 e as públicas aumentaram de 62 para 103. Este é um dos dados da Radiografia das Escolas Médicas Brasileiras, lançada pelo Conselho Federal de Medicina (CFM) em agosto (acessado em 16.09.2015 em http://portal.cfm.org.br/index.php?option=com_content&view=article&id=25714:2015-09-04-21-13-21&catid=3). Este levantamento do CFM revela dados preocupantes sobre a qualidade do sistema formador de novos médicos no país. Só em nosso estado são 1400 vagas, distribuídas em 15 escolas (sete federais e estaduais e oito escolas privadas).Quase ao mesmo tempo, um ranking realizado por um grande jornal brasileiro (Folha de São Paulo, Ranking Universitário Folha 2015, acessado em http://ruf.folha.uol.com.br/2015/) coloca a UFPR na 8º posição dentre todas as universidades brasileiras. Especificamente, quando analisamos o curso de Medicina, caímos para o 29º lugar em nível nacional e somos a 2ª no estado do Paraná (a Universidade Estadual de Maringá é a primeira colocada em nosso estado, na 26º colocação nacional).Obviamente, classificações como esta podem ser questionadas e seus parâmetros discutidos. Um dos critérios utilizados para a categorização das universidades trata de pesquisa médica, avaliada por este ranking como total de publicações, total de citações, citações por artigo, publicações por docente, citações por docente, publicações em revistas nacionais, recursos captados e bolsistas CNPq. Este fato reforça a necessidade de se criar em nossa Universidade uma nova geração de alunos e futuros médicos capacitados com as mais modernas técnicas de metodologia científica. Mesmo para aqueles que não pretendam direcionar sua formação primariamente à pesquisa, o conhecimento metodológico é importante para, por exemplo, ler e interpretar corretamente a literatura médica, tão abundante em quantidade nestas últimas décadas.Desta forma, reforça-se a vocação da RMU como instrumento de divulgação da produção científica local. Modestamente, temos a consciência de estarmos localizados na base da pirâmide em termos de impacto. Muito trabalho existe pela frente. Estamos a cada dia vencendo o desafio da periodicidade. Temos já o ISSN para a versão impressa e eletrônica e estamos nos candidatando para indexação em algumas bases de dados.Ensino, pesquisa e extensão. Vamos criar uma agenda positiva. Evoé!
RELATO DE CASO: FASCEÍTE NECROTIZANTE POR ACINETOBACTER BAUMANII
Authors: Fagundes Grobe Sarah , Perussolo Alberton Helen Carolina , Albanske Raboni Lenisa , Tuon Felipe Francisco
Published: May 2016

A Fasceíte Necrotizante (FN) é uma infecção grave com início súbito e evolução progressiva, com alta mortalidade e que acomete o tecido celular subcutâneo e a fáscia muscular. O trauma é fator de risco para este tipo de infecção. O diagnóstico é clínico e o tratamento baseia-se em intervenção cirúrgica imediata e antibioticoterapia empírica de amplo espectro. O Acinetobacter baumannii apesar de não estar comumente relacionado à FN, possui alta virulência e ampla capacidade de adquirir resistência a antimicrobianos de amplo espectro. Relato de caso: E.P, 29 anos, admitido em um hospital universitário após trauma extenso em membro inferior esquerdo. Submetido a diversas intervenções cirúrgicas com necessidade de amputação transtibial de perna esquerda. Após 48h da amputação, evoluiu com dor intensa no coto cirúrgico, associado a hiperemia local e lesões bolhosas róseas e hemorrágicas. Submetido a reabordagem cirúrgica de emergência e antibioticoterapia empírica de amplo espectro imediatamente. Durante a manipulação cirúrgica, notou-se grande quantidade de necrose e secreção purulenta, sendo necessário ampliação da amputação para nível supracondiliano. Em culturas coletadas, de partes moles e osso, houve crescimento de Enterobacter cloacae e Acinetobacter baumannii, sensível à polimixina e tigeciclina, sendo então realizada antibioticoterapia dirigida com o primeiro antimicrobiano. No 5º dia de tratamento, paciente evolui com piora aguda da função renal, sendo então suspensa  polimixina e iniciado tigeciclina durante 30 dias, com resposta clínica completa. Conclusão: Apesar da grave infecção e da virulência do agente etiológico, o diagnóstico e tratamento precoce foram importantes para a boa evolução do caso relatado.