bluuebunny/crossref_metadata_2025 huggingface dataset:
Lyn-mediated procaspase 8 dimerization blocks apoptotic signaling in B-cell chronic lymphocytic leukemia
Authors: Zonta Francesca , Pagano Mario Angelo , Trentin Livio , Tibaldi Elena , Frezzato Federica , Gattazzo Cristina , Martini Veronica , Trimarco Valentina , Mazzorana Marco , Bordin Luciana , Semenzato Gianpietro , Brunati Anna Maria
Published: December 2013

Key Points

Lyn’s overexpression mediates resistance to apoptosis by promoting phosphorylation and dimerization of procaspase 8 in B-CLL cells.
Hypoglycaemic events in patients with type 2 diabetes in the United Kingdom: associations with patient-reported outcomes and self-reported HbA1c
Authors: Mitchell Beth D , Vietri Jeffrey , Zagar Anthony , Curtis Bradley , Reaney Matthew
Published: December 2013

Background

One possible barrier to effective diabetes self-management is hypoglycaemia associated with diabetes medication. The current study was conducted to characterize hypoglycaemic events among UK patients with type 2 diabetes (T2D) treated with antihyperglycaemic medications, and assess the relationship between experience of hypoglycaemic events and health outcomes, including glycaemic control, health-related quality of life, impairment to work and non-work activities, treatment satisfaction, adherence to treatment, fear of hypoglycaemia, and healthcare resource use.

Methods

An online survey of 1,329 T2D patients in UK drawn from an opt-in survey panel was conducted in February of 2012 with monthly follow-up questionnaires for five months. Measures included self-reported HbA1c, EQ-5D, Work Productivity and Activity Impairment questionnaire, Diabetes Medication Satisfaction Tool, Morisky medication adherence scale, the Hypoglycaemia Fear Survey (revised), and self-reported healthcare resource use. Comparisons were conducted using t-tests and chi-square tests for continuous and categorical variables, respectively.

Results

Baseline comparisons showed that worse HbA1c, greater diabetes-related healthcare resource use, greater fear of hypoglycaemia, and impaired health outcomes were associated with experience of hypoglycaemia in the four weeks prior to baseline. Longitudinal results were similar in direction but differences on few measures were significant.

Conclusions

In real-world UK T2D patients, hypoglycaemia is associated with worse self-reported glycaemic control, behaviours that contribute to worse glycaemic control, and impairment in patient-reported outcomes.
Detecting cellular reprogramming determinants by differential stability analysis of gene regulatory networks
Authors: Crespo Isaac , Perumal Thanneer M , Jurkowski Wiktor , del Sol Antonio
Published: December 2013

Background

Cellular differentiation and reprogramming are processes that are carefully orchestrated by the activation and repression of specific sets of genes. An increasing amount of experimental results show that despite the large number of genes participating in transcriptional programs of cellular phenotypes, only few key genes, which are coined here as reprogramming determinants, are required to be directly perturbed in order to induce cellular reprogramming. However, identification of reprogramming determinants still remains a combinatorial problem, and the state-of-art methods addressing this issue rests on exhaustive experimentation or prior knowledge to narrow down the list of candidates.

Results

Here we present a computational method, without any preliminary selection of candidate genes, to identify reduced subsets of genes, which when perturbed can induce transitions between cellular phenotypes. The method relies on the expression profiles of two stable cellular phenotypes along with a topological analysis stability elements in the gene regulatory network that are necessary to cause this multi-stability. Since stable cellular phenotypes can be considered as attractors of gene regulatory networks, cell fate and cellular reprogramming involves transition between these attractors, and therefore current method searches for combinations of genes that are able to destabilize a specific initial attractor and stabilize the final one in response to the appropriate perturbations.

Conclusions

The method presented here represents a useful framework to assist researchers in the field of cellular reprogramming to design experimental strategies with potential applications in the regenerative medicine and disease modelling.
C/EBP homologous protein drives pro-catabolic responses in chondrocytes
Authors: Husa Matt , Petursson Freyr , Lotz Martin , Terkeltaub Robert , Liu-Bryan Ru
Published: December 2013

Introduction

Excess C/EBP homologous protein (CHOP) expression is one feature of the unfolded protein response (UPR) to endoplasmic reticulum (ER) stress. Here, we focused on CHOP expression and function in chondrocytes.

Methods

We studied human knee osteoarthritis (OA) cartilage, bovine chondrocytes cultured in alginate and subjected to sub-lethal biomechanical injury, and knee chondrocytes of human autopsy donors. We performed siRNA knockdown and transfection.

Results

UPR activation was increased in human knee OA cartilage in situ, and in biomechanically injured cultured chondrocytes in vitro. In normal human chondrocytes, CHOP “gain of function” sensitized chondrocytes to IL-1β induced nitric oxide (NO) and matrix metalloproteinase (MMP)-3 release without inducing these responses by itself. Excess CHOP expression, by itself, induced superoxide production and apoptosis. Conversely, siRNA knockdown of CHOP and the UPR-specific mediator X-box binding protein (XBP1) inhibited NO release by >80% (P <0.0005) in response to IL-1β, and blunted MMP-3 release, whereas there were only minimal effects of the UPR mediator GRP78 on these responses. The anti-inflammatory metabolic “super-regulator” AMP kinase (AMPK) is known to limit UPR activation in vascular muscle cells. Here, CHOP supported the capacity of IL-1β to suppress AMPK activity in chondrocytes. We also observed that inhibition of AMPK activity promoted an increase in chondrocyte CHOP expression. Conversely, pharmacologic activation of AMPK by 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) blunted chondrocyte CHOP expression in response to biomechanical injury.

Conclusions

Biomechanical injury and IL-1 signaling stimulate UPR activation in chondrocytes. CHOP mediates chondrocyte catabolic and apoptotic responses to IL-1β, and does so partly by inhibiting AMPK activity. Conversely, development of excess CHOP activity is limited by AMPK activity in chondrocytes. Our findings suggest a mechanism for potential chondroprotection by AICAR and other AMPK activators. The work is of translational relevance for OA, since several drugs that activate AMPK are already in the clinic for arthritis (for example, allosteric AMPK activators sodium salicylate and high dose aspirin, and methotrexate, which activates AMPK by generating AICAR).
Uma tal de NI047
Authors: De Abreu Sergio Ricardo C. , De Araujo Maria Valeria Pereira , De Araújo Afranio Galdino
Published: December 2013

O novo gerente de auditoria de uma distribuidora de combustíveis nota que pequenos valores considerados não relevantes pelos auditores, quando somados, têm relevância no contexto gerencial. Vale a pena comunicar o Conselho de Auditoria? DOI: 10.12660/gvcasosv3n2c9http://dx.doi.org/10.12660/gvcasosv3n2c9
Livraria Nobel: os dilemas do crescimento (Notas de ensino)
Authors: Da Rocha Angela , Cotta de Mello Renato , Da Silva Gilberto Figueira
Published: December 2013

DOI: 10.12660/gvcasosv3n2n7http://dx.doi.org/10.12660/gvcasosv3n2n7
The nociceptive withdrawal reflex does not adapt to joint position change and short-term motor practice
Authors: Eckert Nathan , Riley Zachary A
Published: December 2013

The nociceptive withdrawal reflex is a protective mechanism to mediate interactions within a potentially dangerous environment. The reflex is formed by action-based sensory encoding during the early post-natal developmental period, and it is unknown if the protective motor function of the nociceptive withdrawal reflex in the human upper-limb is adaptable based on the configuration of the arm or if it can be modified by short-term practice of a similar or opposing motor action. In the present study, nociceptive withdrawal reflexes were evoked by a brief train of electrical stimuli applied to digit II, 1) in five different static arm positions and, 2) before and after motor practice that was opposite (EXT) or similar (FLEX) to the stereotyped withdrawal response, in 10 individuals. Withdrawal responses were quantified by the electromyography (EMG) reflex response in several upper limb muscles, and by the forces and moments recorded at the wrist. EMG onset latencies and response amplitudes were not significantly different across the arm positions or between the EXT and FLEX practice conditions, and the general direction of the withdrawal response was similar across arm positions. In addition, the force vectors were not different after practice in either the practice condition or between EXT and FLEX conditions. We conclude the withdrawal response is insensitive to changes in elbow or shoulder joint angles as well as remaining resistant to short-term adaptations from the practice of motor actions, resulting in a generalized limb withdrawal in each case. It is further hypothesized that the multisensory feedback is weighted differently in each arm position, but integrated to achieve a similar withdrawal response to safeguard against erroneous motor responses that could cause further harm. The results remain consistent with the concept that nociceptive withdrawal reflexes are shaped through long-term and not short-term action based sensory encoding.
Topological Closure of Translation Invariant Preorders
Authors: Ok Efe A. , Riella Gil
Published: December 2013

Our primary query is to find conditions under which the closure of a preorder on a topological space remains transitive. We study this problem for translation invariant preorders on topological groups. The results are fairly positive; we find that the closure of preorders and normal orders remain as such in this context. The same is true for factor orders as well under quite general conditions. In turn, in the context of topological linear spaces, these results allow us to obtain a simple condition under which the order-duals with respect to a vector order and its closure coincide. Various order-theoretic applications of these results are also provided in the paper.
Legacy Divestitures: Motives and Implications
Authors: Feldman Emilie R.
Published: December 2013

This paper investigates “legacy divestitures,” the sale or spinoff of a company’s original, or “legacy,” business. The central tension considered in this work is that the historical presence of a firm’s legacy business should simultaneously make that unit very interdependent with the company’s remaining operations and make the firm’s managers highly likely to take those same interdependencies for granted. Consistent with these predictions, the post-divestiture operating performance of firms that divest their legacy businesses falls short of that of firms that retain comparable legacy units, especially when the divested unit operates in the same industry as others of the divesting firm’s businesses. Newer chief executive officers (CEOs) are more likely to undertake legacy divestitures than their longer-tenured peers, and the most recently appointed CEOs undertake the most costly legacy divestitures. In summary, this paper provides insights into how historical interdependencies create value in diversified firms, as well as the decision-making processes that managers follow in overseeing these companies.
Effect of Barley Flour on Texture and Sensory Characteristics of Garraedduk Prepared by Retrogradation-Retardation Technology
Authors: Lee Jun Woo , Bae In Young , Kim Hong Sul , Oh Im Kyung , Kim Myung Hwan , Han Gwi Jung , Lee Hyeon Gyu
Published: December 2013

Retrogradation-retardation technology was utilized to prepare Garaedduk with different levels of barley flour for rice flour (0, 15, 30, and 45% by weight). Their physicochemical and sensory characteristics were evaluated before and after storage for 3 days at 4°C. The moisture contents of Garaedduk were reduced by increasing the ratios of barley flour while the color differences became distinct. After the storage, the Garaedduk with 15% of barley flour exhibited similar hardness in control without barley flour. The sensory evaluation showed that the overall acceptability of Garaedduk decreased with increasing levels of barley flour. However, there was no significant difference in the overall acceptability of Garaedduk with 0 and 15% of barley flour. The sensory attributes of freshly made Garaedduk were highly correlated with moisture (positive) and hardness (negative). After storage, the sensory attributes of Garaedduk showed positive correlation with adhesiveness. Therefore, rice flour can be replaced with barley flour up to 15% under the condition of retrogradation-retardation technology in order to produce Garaedduk without significant quality loss.
Changes of Proteins and Physicochemical Properties of Cow's Milk by High Voltage Pulsed Electric Field Treatment
Authors: Lee Sulhee , Kim Gun , Park Young-Seo
Published: December 2013

Raw milk, skim milk, HTST-, LTLT-, and UHT-milk were treated with pulsed electric field (PEF) process and the changes in proteins and physicochemical properties of milk were examined. When protein profiles in samples were identified by SDS-PAGE, the denaturation of milk proteins by PEF treatment was not observed. When the denaturation temperature (Td) of milk proteins was analyzed with a differential scanning calorimetry (DSC), the Td of skim milk treated with PEF at 65°C increased from 87.66 to 97.18°C, which indicated that PEF treatment affected the denaturation of milk protein. The PEF treatment of raw milk and skim milk resulted in the decrease of alkaline phosphatase activity, whereas protease and lactoperoxidase activities were not affected. Raw milk treated with PEF at 65°C showed more browning reaction than non-treated raw milk. The pH and titratable acidity of milk were not affected by PEF treatment.
Development of Rapid Detection Kit for Aflatoxin B1 in Cereals
Authors: Choi Sunmi , Kim Giyoung , Lee Sangdae , Moon Jihea , Om Aeson
Published: December 2013

The aim of this study is to develop the one dot rapid detection kit that meets the limit of detection (LOD) of KFDA (10 μg/kg) for Aflatoxin B1 (AFB1). The fabrication process of the one dot rapid detection kit, such as gold nanoparticle and AFB1-BSA conjugation, and AFB1-polyclonal antibody concentration was optimized. Fabricated rapid detection kits were tested with the standard AFB1 solutions and the solutions extracted from contaminated maize samples. The LOD in the standard AFB1 solution and extracted AFB1 solution was 5 μg/kg for both. This result is lower than the LOD of KFDA in food (10 μg/kg) and satisfies the LOD of EU (2-12 μg/kg) and Japan (10 μg/kg) in food.
Estimating Causal Effects in Observational Studies Using Electronic Health Data:
Challenges and (some) Solutions
Authors: Stuart Elizabeth A. , DuGof Eva , Abrams Michael , Salkever David , Steinwachs Donald
Published: December 2013

Electronic health data sets, including electronic health records (EHR) and other
administrative databases, are rich data sources that have the potential to help answer
important questions about the effects of clinical interventions as well as policy
changes. However, analyses using such data are almost always non-experimental, leading
to concerns that those who receive a particular intervention are likely different from
those who do not, in ways that may confound the effects of interest. This paper outlines
the challenges in estimating causal effects using electronic health data, and offers
some solutions, with particular attention paid to propensity score methods that help
ensure comparisons between similar groups. The methods are illustrated with a case study
describing the design of a study using Medicare and Medicaid administrative data to
estimate the effect of the Medicare Part D prescription drug program among individuals
with serious mental illness.
The Enhanced Cognitive Interview: Towards a Better Use and Understanding of This Procedure
Authors: Paulo Rui M. , Albuquerque Pedro B. , Bull Ray
Published: December 2013

The Enhanced Cognitive Interview is accepted as one of the most successful techniques for enhancing witness recollection. This type of interview has been studied all over the world (eg, Europe or the USA) and is used by police officers in many different countries (eg, the UK and New Zealand). Nonetheless, it is essential for police officers to understand how, and when, to properly apply this interview. Therefore, we examined the underlying psychological processes involved in this interview, and what research can tells us about the situations and purposes that can benefit from applying it.
A Novel Modified Starch/Carboxymethyl Cellulose/Montmorillonite Bionanocomposite Film: Structural and Physical Properties
Authors: Ghanbarzadeh Babak , Almasi Hadi , Oleyaei Seyed Amir
Published: December 2013

A novel glycerol-plasticized and citric acid (CA)-modified starch/carboxymethyl cellulose (CMC)/montmorillonite (MMT) bionanocomposite films were prepared from corn starch by casting, to study the effect of the 10% CA, 10% CMC and four different loadings of MMT on the properties of starch films. Atomic force microscopy surface analysis showed that starch/CMC/MMT films had the highest roughness. X-ray diffraction test showed that the clay nanolayers formed an intercalated structure in the bionanocomposites. However, completely exfoliated structure formed only in the pure starch/MMT nanocomposites (without CA and CMC). CA, CMC and MMT improved mechanical properties of starch films. MMT had the greatest effect on the mechanical properties. The MMT addition at content of 7% caused to increase in ultimate tensile strength by more than threefold in comparison to modified starch/CMC films. The water vapor permeability (WVP) decreased significantly (p < 0.05) by the addition of CA and CMC. When the MMT content of the starch films reached to 7%, the WVP decreased about 75% in comparison to the neat starch film. However, the hydrophilic character of bionanocomposites increased as the increasing of MMT content.
Maximizing Lyapunov Exponents in a Chaotic Oscillator by Applying Differential Evolution
Authors: Carbajal-Gómez V.H. , Tlelo-Cuautle E. , Fernández F.V. , de la Fraga L.G. , Sánchez-López C.
Published: December 2013

This paper shows the application of the heuristic Differential Evolution (DE) algorithm to maximize the positive Lyapunov exponent in a third-order multi-scroll chaotic oscillator. The case of study is the saturated nonlinear function series-based chaotic oscillator. The positive Lyapunov exponent is computed for a 4-scrolls chaotic oscillator by varying the coefficients of the dynamical system (a, b, c, d
1), in the range [0.001..1.000]. The experiments are performed and compared executing DE and a simple Genetic algorithm. The results show that DE algorithm is quite suitable to maximize the positive Lyapunov exponent of truncated coefficients over the continuous parameter spaces, because statistical studies show a small standard deviation. The comparison of the phase space diagrams of non-optimized and optimized chaotic oscillators show that for a low value of the positive Lyapunov exponent the attractor is well defined, while for its maximum value the attractor is not well appreciated, but the higher value of the exponent increases the unpredictability grade of the chaotic system.
Antiviral activity of interferon-γ involved in impaired immune function in infectious diseases
Authors: Sucher Robert , Kurz Katharina , Margreiter Raimund , Fuchs Dietmar , Brandacher Gerald
Published: December 2013

Pro-inflammatory cytokines like interferon-γ (IFN-γ) play dominant roles in pathophysiologic conditions like infections, cardiovascular and neurodegenerative disorders and autoimmune syndromes. As part of its antimicrobial and immunomodulatory armature, the tryptophan-degrading enzyme indoleamine (2,3)-dioxygenase (IDO) is mainly up-regulated in dendritic cells (DCs) and phagocytes by pro-inflammatory stimuli, most notably IFN-γ. By the breakdown of the essential amino acid l-tryptophan along the kynurenine pathway, IDO plays a key role in the inhibition of cell proliferation including that of activated T cells, thereby supporting immune tolerance in mammalian pregnancy, tumor development, allergic inflammation and allotransplantation. IFN-γ-induced tryptophan deprivation also seems to be involved in the pathogenesis of anemia and cachexia when erythroid progenitor cells suffer from insufficient amino acid supply or when protein biosynthesis of the organism is restricted by diminished tryptophan availability. This biochemical cascade seems also to be involved in the production of potentially neurotoxic tryptophan catabolites such as quinolinic acid, which ultimately leads to the development of neuropsychiatric symptoms like cognitive impairment and depression especially in patients suffering from severe and chronic infections.
Failure Analysis on 410 Stainless Square-Head Bolts Failing Wedge Tensile Test
Authors: Chimbli Sri Krishna
Published: December 2013

ASTM A193-12, grade B6 (Gr.B6), 3/4 in. (19.05 mm) in diameter by 4 in. (101.6 mm) in length, square-head bolts were breaking at the head to shank juncture during wedge tensile testing. Specimens from the same lot did meet the requirements of Gr.B6 for tensile strength, hardness, reduction of area, and elongation. Failure analysis was performed on the lot to indicate whether the discrepancy is with integrity of steel, forging or heading process, or the heat treatment. The investigation was carried out by dimensional inspection, visual inspection, chemical analysis, hardness and tensile test, scanning electron microscopy (SEM) analysis, and microstructure evaluation. SEM analysis indicated that the cause of fracture is because of embrittlement. The microstructure evaluation had showed the presence of tempered martensite in the core and needle martensite with retained austenite on the surface. Failure analysis concluded that cause of failure was because of the formation of unstable microstructure during heat treatment. The retained austenite with needle martensite structure had an average Vickers hardness (HV) of 301 at the surface and the tempered martensite structure had an average Vickers hardness of 262 HV at the core that led to a brittle failure on wedge tensile test. The lot was recommended to be re-tempered at 1180°F (637°C) with a holding time of 2.0 h to meet the requirements of wedge tensile testing.
Kompaktes photoakustisches Gasmesssystem mit
Potential zur weiteren Miniaturisierung
Authors: Huber Jochen , Wöllenstein Jürgen
Published: December 2013

Der photoakustische Effekt kann zur Detektion von IR-aktiven
Gasen genutzt werden. Es wird ein einfaches und kompaktes System
vorgestellt, welches nach theoretischen Vorbetrachtungen
entwickelt wurde. Das System besteht aus einem thermischen
Breitband-IR-Emitter und einer Messkammer mit einem MEMS-Mikrofon
als Detektor. Labormessungen mit den Gasen Kohlendioxid und Methan
zeigen die Eignung als selektives und kostengünstiges
Messsystem. Das Potential zur weiteren Miniaturisierung des
Messsystems wird aufgezeigt.
Surfaces and Interfaces of Nanoscale Silicon Materials
Authors: Wagner Sean R. , Zhang Pengpeng
Published: December 2013

Surfaces and interfaces play a critical role in determining properties and functions of nanomaterials, in many cases dominating bulk properties, owing to the large surface- and interface-area-to-volume ratio. Using Si nanomembranes, a well-controlled two-dimensional single-crystalline semiconductor, as a prototype system, we discuss how surfaces and interfaces influence electrical transport properties at the nanoscale. We show that electronic conduction in Si nanomembranes is not determined by bulk dopants but by the interplay of surface and interface electronic structures with the “bulk” band structure of the thin Si membrane. Additionally, we describe our recent experimental results on the control of highly ordered molecular structures on Si surfaces, which is of intense interest for the integration of ordered organic thin films in silicon-based electronics. This could also potentially lead to the rational design of Si nanostructures with controlled properties through regulation of the surface chemistry.
Nonvolatile memory MOS capacitors made of CdSe embedded ZrHfO high-k gate dielectric
Authors: Lin Chi-Chou , Kuo Yue
Published: December 2013

MOS capacitor composed of nc-CdSe embedded ZrHfO high-k gate dielectric stack was fabricated and characterized for nonvolatile memory functions. Detailed material and electrical properties have been investigated. With a large charge trapping capability, this kind of device can trap electrons or holes depending on the polarity and magnitude of the applied gate voltage. For the same stress time, the device trapped more holes than electrons under the same magnitude of gate voltage but different polarity. The negative differential resistance peak was observed at the room temperature due to the Coulomb blockade effect. The charge trapping mechanism was delineated with the constant voltage stress test. After 10 years of storage, about 56% of trapped charges still remain in the device.
Memory Characteristics of Filament Confined in Tiny ReRAM Structure
Authors: Koh S. G. , Kinoshita K. , Fukuhara T. , Sawai Y. , Kishida S.
Published: December 2013

Clarification of memory characteristics of tiny cell is important for practical use of resistive random access memory (ReRAM). However, limitation of semiconductor micro-fabrication technology hinders to obtain memory characteristics in tiny cell with an area comparable to the size of filaments. In this paper, we established a method to prepare a very small memory cell by fabricating ReRAM structure on the tip of a cantilever of atomic force microscope (AFM). We also established a method to avoid the overshoot of set current. As a result, reset current was successfully reduced enough to suppress serious damage to the cantilever. The effective cell size was estimated to be less than 10 nm in diameter due to electric field concentration at the tip of the cantilever, which was confirmed by an electric field simulator based on finite element method. We performed a unique experiment to verify the presence of oxygen pool in an anode, by utilizing removable bottom electrode structure. The result was not consistent with resistive switching models that require the anode to play a role as an oxygen reservoir.
SiC multilayer add/drop filter for optical interconnects
Authors: Vieira M. , Vieira M. A , Louro P. , Silva V. , Costa J.
Published: December 2013

In this paper we demonstrate an add/drop filter based on SiC technology. Tailoring of the channel bandwidth and wavelength is experimentally demonstrated. The concept is extended to implement a 1 by 4 wavelength division multiplexer in the visible range.The add/drop filter consists of a p-i'(a-SiC:H)-n/p-i(a-Si:H)-n photodetector with two front and back optical gates. Tailoring the filter wavelength is achieved by applying a 400 nm background and changing front and back biased optical gates. Results show that, front background enhances the light-to-dark sensitivity of the long and medium wavelength channels and quench strongly the others. Back violet background has the opposite behavior; it enhances channel magnitude in short wavelength range and reduces it in the long ones. This nonlinearity provides the possibility for selective removal or addition of wavelengths. An optoeletronic model gives insight on the system physics and explains the light filtering properties of the add/drop filter.
Post-etch treatment enabled electroless copper metallization of porous dielectric
Authors: Dordi Yezdi N.
Published: December 2013

This paper describes an alternate two-step metallization scheme for porous dielectrics. The patterned dielectric surface is first treated in a plasma etch chamber where the dielectric surface is coated with a very thin carbon-based film. This is followed by electroless copper deposition. The plasma post-etch treatment (PET) film seals the pores of the dielectric, minimizes dielectric damage, and functionalizes the dielectric to enable electroless plating.
Active Flexible Strain Sensor Based on Single ZnO Micro/Nanowire
Authors: Lin Pei , Cui Yan , Yan Xiaoqin , Zhang Zheng , Wang Peng , Zhang Yue
Published: December 2013

A facile and cost-effective fabrication approach of active strain sensor based on individual ZnO micro/nanowire was demonstrated. By connecting a ZnO micro/nanowire along polar growth direction with two Ag electrodes on flexible polystyrene (PS) substrate, the fabricated strain sensor was obtained as a typical M-S-M structure. The I-V characteristic of the device was highly sensitive to the strain caused by the obvious change of Schottky barrier height (SBH). Furthermore, both of the symmetric and asymmetric changes of the SBH at the source and drain were observed during device testing process. The respective contribution of piezoresistance effect and the piezoelectric effect to the change of SBHs were also systematically investigated.
Universal Anisotropically Conductive Nano-adhesive of PDMS Oligomers
Authors: Ding Yuzhe , Garland Shaun , Howland Michael , Revzin Alexander , Pan Tingrui
Published: December 2013

A nanopatternable oligomeric PDMS layer has been first verified as a nano-adhesive for its intrinsic transferability and universal adhesiveness. Utilizing the well-established PDMS surface modification and bonding techniques, we have been able to form irreversible bonding between a wide range of substrate pairs, representing ones within and across different material categories, including metals, ceramics, thermoset, and thermoplastic polymers. The anisotropic conductivity of the PDMS oligomer nano-adhesive has been investigated, which allows specific and excellent directional conductivity between bonded electrodes without risk of electrical shorts across different contacts.
Development of AlAsSb as a barrier material for ultra-thin-channel InGaAs nMOSFETs
Authors: Huang Cheng-Ying , Law Jeremy J. M. , Lu Hong , Rodwell Mark J. W. , Gossard Arthur C.
Published: December 2013

We investigated AlAs0.56Sb0.44 epitaxial layers lattice-matched to InP grown by molecular beam epitaxy (MBE). Silicon (Si) and tellurium (Te) were studied as n-type dopants in AlAs0.56Sb0.44 material. Similar to most Sb-based materials, AlAs0.56Sb0.44 demonstrates a maximum active carrier concentration around low-1018 cm-3 when using Te as a dopant. We propose the use of a heavily Si-doped InAlAs layer embedded in the AlAsSb barrier as a modulation-doped layer. The In0.53Ga0.47As/AlAs0.56Sb0.44 double heterostructures with a 10 nm InGaAs well show an electron mobility of about 9400 cm2/V・s at 295 K and 32000 cm2/V・s at 46 K. A thinner 5 nm InGaAs well has an electron mobility of about 4300 cm2/V・s at 295 K. This study demonstrates that AlAs0.56Sb0.44 is a promising barrier material for highly scaled InGaAs MOSFETs and HEMTs.
High-Performance MIM Capacitors based on TiO2/ZrO2/TiO2 and AlO-doped TiO2/ZrO2/TiO2 Dielectric Stacks for DRAM Applications
Authors: Padmanabhan Revathy , Bhat Navakanta , Mohan S. , Morozumi Y. , Kaushal Sanjeev
Published: December 2013

Metal-insulator-metal (MIM) capacitors for DRAM applications have been realized using TiO2/ZrO2/TiO2 (TZT) and AlO-doped TZT (TZAZT and TZAZAZT) dielectric stacks. High capacitance densities of about 46.6 fF/μm2 (for TZT stacks), 46.2 fF/μm2 (for TZAZT stacks), and 46.8 fF/μm2 (for TZAZAZT stacks) have been achieved. Low leakage current densities of about 4.9×10−8 A/cm2, 5.5×10−9 A/cm2, and 9.7×10−9 A/cm2 (at -1 V) have been obtained for TZT, TZAZT, and TZAZAZT stacks, respectively. We analyze the leakage current mechanisms at different electric field regimes, and compute the barrier heights. The effects of constant current stress and constant voltage stress on the device characteristics are studied, and excellent device reliability is demonstrated. We compare the device performance of the fabricated capacitors with other stacked high-k MIM capacitors reported in recent literature.
Vibrational distortions of the Au7+ hexagonal cluster
Authors: Soto J. R. , Molina B. , Castro J. J.
Published: December 2013

The study of the 2D-3D structural transition in Au7+ nanocluster as a function of the number of gold atoms has been a long standing problem due to contradictory results between experiments, that show a 2D structure, and some theoretical results predicting 3D. We present a theoretical analysis, based on the pseudo Jahn-Teller effect that explains the origin of the 2D-3D structural transition controversy. It is shown that the usually assumed 2D non-degenerate ground state cluster structure with D6h symmetry is unstable due to a vibronic coupling between the ground state and one excited state, producing a puckering effect ending in a 3D stable structure with D3d symmetry. This structure presents the same surface area than the 2D, being therefore compatible with ion mobility experimental results. We discuss the effect of symmetry breaking on the Raman, IR and UV-vis spectra, which might indicate some possible sensor capabilities for this subnanometric cluster. The study is based on scalar relativistic and time-dependent DFT calculations in the Zero Order Regular Approximation (ZORA).
Analysis of Cu-Line EM Failure Kinetics Using Mass Transport TCAD Simulations
Authors: Lee Mankoo , Zhang Xuena , Pramanik Dipankar
Published: December 2013

We describe a mass transport TCAD simulation by using a Sentaurus S-Interconnect tool [1] that models reported electro-migration (EM) behaviors: EM induced resistance (R) change, line length (L) effect, and temperature (T) dependency on L and current density (j) products. We performed trend and sensitivity analyses for key physical EM model parameters: Cu-void formation, a sudden jump in line R associated with void growth, and Cu-vacancy (Cv) and void (Cvoid) profiles. In this manner, we develop a new methodology for accurately determining the EM lifetime by identifying an “EM-aware” region to define the L dependence of Cu-lines under high current stress. This includes electron flow dependency to explain line and via depletion effects for void formations under various stress conditions. We report a non-linearity in the L dependence on the jL product and a slight temperature dependence on the Blech Threshold (jL)c.
Materials and scaling effects on on-chip interconnect reliability
Authors: Hu C.-K. , Liniger E. G. , Gignac L. M. , Bonilla G. , Edelstein D.
Published: December 2013

Scaling effects on Cu microstructure, resistivity, dielectric materials, and electromigration (EM) and time dependent dielectric break down (TDDB) reliabilities for Cu interconnects were reviewed. A simple empirical model of Cu resistivity related to Cu line area was presented. Cu line microstructures containing small grains mixed with large bamboo grains in Cu damascene lines from technology nodes below 65 nm were observed. As predicted in previous work, the EM lifetime was found to degrade by about 50% for every new generation even for the same current density. The Cu grain size was found to have a large impact on pure Cu and Cu alloy EM lifetime and activation energy Ea. Ea for pure Cu line capped with selective electroless CoWP on near-bamboo, bamboo-polycrystalline, to polycrystalline only line grain structures was reduced from 2.2 eV to 1.7 eV to 0.75 eV, respectively. Ea for 40 nm wide bamboo-polycrystalline lines capped with selective chemical vapor deposition (CVD) Co was found to be 1.7 eV. Using pure Cu and Cu(Al) or Cu(Mn) diluted impurity seed layers in 40 nm wide, bamboo-polycrystalline microstructure lines and above 100 nm wide, near bamboo-like grained lines, Cu-alloy lines enhanced EM lifetimes and increased QEM from 0.9 to 1. eV and 1.0 to 1.2 eV, respectively, compared to pure Cu lines. Inter-level TDDB testing on vias connecting M1 to M2 with a via chamfer angle that varied from 58o to 81o have very similar performance with intra-level M2 data with no vias tested at the same field. This result combined with the data from a separate study, which allowed the chamfer path to be isolated from the M2-level path, suggested that the failure took place preferentially along the weak cap/ILD interface at M2 and not at the via chamfer. TDDB acceleration data indicated that the root E model was overly conservative and a more aggressive model provided a better fit to the data. TDDB lifetimes correlated fairly well with the percentage of porosity in the dielectric materials.
A Fast, Experimentally validated, Particle Augmented Mixed Lubrication Framework to Predict CMP
Authors: Srivastava Gagan , Higgs C . Fred
Published: December 2013

Fabrication of integrated circuits is a multi-step process that involves chemical mechanical polishing (CMP) for planarizing the deposited layers. Although dependent on the consumables and machine operating conditions, most CMP researchers assume that the polishing occurs in the mixedlubrication 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. The particle augmented mixed lubrication (PAML) approach has been employed by Terrell and Higgs (2009) as a high-fidelity asperity-scale mixed-lubrication CMP model. The current work introduces a more computationally efficient wafer-scale PAML model, called PAML-lite, which employs a two-dimensional average flow Reynold's Equation incorporating spatial dependence of entrainment velocities to model the hydrodynamic pressure. The contact mechanics are modeled using a Winkler elastic foundation in cylindrical polar coordinates. The resulting slurry hydrodynamic pressure distribution and contact stress are used to determine the equilibrium configuration of the system in the form of a nominal clearance and rolling and pitch angles. Local and wafer scale material removal rate (MRR) is predicted by assuming a uniform distribution of particle sizes. The prediction of PAML-lite were then benchmarked against experimental results. Upon verification, parametric studies were conducted to understand the effect of some unexplored CMP parameters.
Reducing density-induced CMP non-uniformity for advanced semiconductor technology nodes
Authors: Zhang John H , Tseng Wei-Tsu , Chen Tien , Kim Ben , Flaitz Philip , Kleemier Walter , Goldberg Cindy , Truong Connie , Grunow Stephan
Published: December 2013

In this paper, a novel set of macros with line/space width from 128nm/128nm, 64nm/64nm to 32nm/32nm was designed and installed on 20nm technology-node hardware. The pitch-dependent pad erosion post Cu CMP was studied by atomic-force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) quantitatively on these macros. Two methods were investigated to reduce the difference between pitch- and density-induced CMP non-uniformity. The first is using new scheme of partial Cu plating process followed by SiCNH insulator deposition and then CMP. The second is through the selection of slurries and pads. Both results are discussed in this paper.
Eletroforese em papel das proteínas do líqüido cefalorraquidiano: III. Técnica
Authors: Spina-França A.
Published: December 2013

A técnica utilizada pelo autor para a eletroforese em papel das proteínas do liqüido cefalorraquidiano é descrita em detalhe, segundo a experiência já obtida no laboratório da Clínica Neurológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Atendendo à utilidade prática de exame eletroforético das proteínas do sôro sangüíneo, é exposta também a técnica utilizada para êste exame.
Educação interprofissional: formação de profissionais de saúde para o trabalho em equipe com foco nos usuários
Authors: Peduzzi Marina , Norman Ian James , Germani Ana Claudia Camargo Gonçalves , Silva Jaqueline Alcântara Marcelino da , Souza Geisa Colebrusco de
Published: December 2013

São analisados os constructos teóricos da educação interprofissional com base em duas revisões de literatura, considerado o contexto da formação dos profissionais de saúde no Brasil. Identificam-se três tipos de formação: uniprofissional, multiprofissional e interprofissional, com predomínio da primeira, que ocorre entre estudantes de uma mesma profissão de forma isolada; a segunda, entre estudantes de duas ou mais profissões de forma paralela, sem haver interação, e na terceira há aprendizagem compartilhada, com interação entre estudantes e/ou profissionais de diferentes áreas. Destaca-se a distinção entre interprofissionalidade e interdisciplinaridade, referidas, respectivamente, como a integração das práticas profissionais e das disciplinas ou áreas de conhecimento. Mediante a análise apresentada, conclui-se que no contexto brasileiro, a educação interprofissional, base para o trabalho em equipe colaborativo, ainda está restrita a iniciativas recentes, que merecem estudo.
Impacto do manejo da água na toxidez por ferro no arroz irrigado por alagamento
Authors: Schmidt Fabiana , Fortes Magali de Ávila , Wesz Jonas , Buss Gerson Lubke , Sousa Rogério Oliveira de
Published: December 2013

A toxidez por ferro é o distúrbio nutricional de maior ocorrência em arroz (Oryza sativa L.) cultivado em sistemas alagados, derivada da quantidade excessiva de íons ferrosos (Fe2+) gerados pela redução de óxidos de ferro em solos alagados. Em experimento conduzido em casa de vegetação, foram avaliados os efeitos de manejos da água de irrigação na dinâmica de redução de um Planossolo e na manifestação da toxidez por ferro em arroz. Os tratamentos dispostos em blocos completos ao acaso com quatro repetições constaram de cinco manejos da água: T1- início do alagamento no estádio V2-V3 do arroz; T2- início do alagamento no estádio V6-V7; T3- T1 e drenagem no estádio V10-V11; T4- T2 e drenagem no estádio V10-V11; e T5- T1 e drenagens nos estádios V7-V8 e V10-V11. O atraso do início do alagamento para o estádio V6-V7 do arroz manteve os valores do Eh da solução do solo mais elevados, promovendo menor disponibilidade de Fe2+ na solução do solo e deslocando a máxima liberação de Fe2+ na solução do solo para estádios fenológicos mais avançados do arroz. A realização de drenagens ao longo do ciclo vegetativo do arroz promoveu a reoxidação do solo, que ocasionou o aumento dos valores de Eh e redução da concentração de Fe2+ na solução do solo. O uso de drenagens durante o período vegetativo do arroz foi eficiente no controle da toxidez por excesso de ferro, em arroz cultivado em solo alagado.
Arsenic toxicity in Acacia mangium willd. and mimosa Caesalpiniaefolia benth. seedlings
Authors: Cipriani Henrique Nery , Dias Luiz Eduardo , Costa Maurício Dutra , Campos Naiara Viana , Azevedo Aristéa Alves , Gomes Roberto Junio , Fialho Izabela Ferreira , Amezquita Sandra Patrícia Montealegre
Published: December 2013

Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As)-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg-1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg-1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used.
Potencialidades no ensino-aprendizagem da comunicação médico-paciente em três escolas brasileira, espanhola e holandesa
Authors: Dohms Marcela , Tesser Charles Dalcanale , Grosseman Suely
Published: December 2013

Está bem estabelecida a necessidade de incluir o ensino da comunicação no currículo das escolas médicas de forma sistemática. Objetivo: Conhecer a percepção de estudantes de Medicina de três escolas médicas de países diferentes (Brasil, Espanha e Holanda) e as potencialidades de cada uma destas escolas no processo de ensino-aprendizagem da comunicação médico-paciente. Método: Estudo exploratório qualitativo, com estudantes do último ano de Medicina, mediante entrevista semiestruturada, observação direta e análise temática de conteúdo. No Brasil, foram utilizados dados secundários de pesquisa similar. Resultados: As principais potencialidades encontradas foram a aprendizagem por modelos, com pacientes simulados, uso de videogravação e a Atenção Primária da Saúde (APS) como ambiente de ensino. Conclusão: A associação dessas potencialidades no ensino, com inserção do estudante na APS desde o início do curso, inclusão de pacientes simulados e videogravação, pode maximizar a aprendizagem da comunicação-médico paciente.
Dimensão psicológica da qualidade de vida de estudantes de Medicina
Authors: Gonçalves Sofia Senna , Silvany Neto Annibal Muniz
Published: December 2013

Objetivos: Avaliar a Dimensão Psicológica da Qualidade de Vida (DPQV) dos estudantes de Medicina da Universidade Federal da Bahia, caracterizar a população segundo variáveis sociodemográficas e epidemiológicas, e identificar possíveis fatores associados. Método: Estudo transversal baseado em questionário autoaplicável com questões da DPQV propostas pela OMS, aplicado aos estudantes do primeiro ao oitavo semestre. Resultados: Os fatores relevantes de aumento da prevalência de baixa DPQV foram: estar cursando o segundo ano; ser do sexo feminino; ser casado(a); morar com os pais versus morar sozinho ou com outras pessoas; renda familiar menor que 15 salários mínimos ou não saber a renda familiar versus renda de mais de 15 salários mínimos; ter escolhido cursar Medicina por motivos não relacionados à aptidão; não dispor de dinheiro suficiente para as necessidades cotidianas; não ter atividades extra-acadêmicas prazerosas; insatisfação com o custo das refeições, a qualidade dos livros na biblioteca e a segurança no ambiente da faculdade; alimentação não saudável; ingerir álcool versus nenhuma ingestão; e fazer ou ter feito uso de drogas ilícitas. Conclusão: Os resultados sugerem influência do curso de Medicina na DPQV.