bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebro-cerebellar Interactions Underlying Temporal Information Processing
Authors: Aso Kenji , Hanakawa Takashi , Aso Toshihiko , Fukuyama Hidenao
Published: January 2010

The neural basis of temporal information processing remains unclear, but it is proposed that the cerebellum plays an important role through its internal clock or feed-forward computation functions. In this study, fMRI was used to investigate the brain networks engaged in perceptual and motor aspects of subsecond temporal processing without accompanying coprocessing of spatial information. Direct comparison between perceptual and motor aspects of time processing was made with a categorical-design analysis. The right lateral cerebellum (lobule VI) was active during a time discrimination task, whereas the left cerebellar lobule VI was activated during a timed movement generation task. These findings were consistent with the idea that the cerebellum contributed to subsecond time processing in both perceptual and motor aspects. The feed-forward computational theory of the cerebellum predicted increased cerebro-cerebellar interactions during time information processing. In fact, a psychophysiological interaction analysis identified the supplementary motor and dorsal premotor areas, which had a significant functional connectivity with the right cerebellar region during a time discrimination task and with the left lateral cerebellum during a timed movement generation task. The involvement of cerebro-cerebellar interactions may provide supportive evidence that temporal information processing relies on the simulation of timing information through feed-forward computation in the cerebellum.
Fixed boundaries, fluid landscapes
Authors: Cederlöf Gunnel
Published: January 2010

This article focuses on questions of the formation of new polities and ruler–subject relations as a result of British colonial conquest of northern east Bengal and neighbouring states in the early nineteenth century. It emphasises ecological and climatic structuring conditions and is a contribution to research on changing spatial relations and transactions, transformation of hill–plain relations, and collisions between synoptic political visions and knowledge systems, and their implementation on particular landscapes and people. Particular attention is given to the time and place–bound formation of law for the control and access of land and natural resources.

The study thus explores the tense relationship between a fluid, continuously changing land-scape and the fixed notions of boundaries, government control and polities held by the British East India Company (EIC) and which they strove to implement in military and fiscal control in northern east Bengal. The study suggests that the means and principles by which bureaucratic control was established formed the basis for a form of fiscal citizenship whereby the subject was acknowledged as a person with rights and in communication with government. Such control was established in the former Nawab’s territories which mainly consisted of plains and therefore were landscapes that were intended to be agrarian. It is further suggested that when the neighbouring independent states and autonomous villages were brought under EIC rule, this was done by other means which in turn shaped different ruler–subject relations and eventually paved the way for the formation of dual polities under one government.
Telling her tale? Unravelling a life in conflict in Peero’s Ik Sau Saṭh Kāfiaṅ. (one hundred and sixty kafis)
Authors: Malhotra Anshu
Published: January 2010

This article explores the manner in which Peero, a denizen of nineteenth century Punjab, in her 160 Kafis tries to communicate aspects of her own story and life through the diverse cultural resources at her command. The questions of self-representation and self-fashioning are central to this text, and Peero speaks of certain events in her life by relating sagas and evoking moods familiar in the cultural landscape of Punjab. Peero, self-confessedly a prostitute, and a Muslim, came to live in the middle of the nineteenth century in the Gulabdasi dera, a nominally ‘Sikh’ sect. This remarkable move, and her relationship with Guru Gulab Das, probably generated discord that pushed Peero into inserting her ‘self’ into the 160 Kafis. An attempt is made to read Peero’s crafting of her story, along with her silences, and bring out the nuances embedded in her text. The article also examines why Peero writes of her personal trauma and experience in the language of religious conflict between the ‘Hindus’ and the ‘Turaks’. This was particularly surprising as the Gulabdasi dera displayed eclecticism in its philosophical choices, and imbibed radical aspects of Vedantic monism. It also borrowed freely from hybrid religious sources including rhetoric familiar within the Bhakti movement, and the Punjabi Sufis’ anti-establishment mien.
Time to Prison Return for Offenders With Serious Mental Illness Released From Prison
Authors: Cloyes Kristin G. , Wong Bob , Latimer Seth , Abarca Jose
Published: January 2010

Serious mental illness (SMI) represents a major risk for repeated incarceration, yet recidivism studies often do not specifically focus on persons with SMI as compared to non-SMI offenders. The study reported here systematically identified Utah State prisoners released from 1998 to 2002 ( N = 9,245) who meet criteria for SMI and compared SMI and non-SMI offenders on length of time to prison return. Findings indicate that 23% of the sample met criteria for SMI ( n = 2,112). Moreover, survival analyses demonstrated a significant difference in return rates and community tenure for offenders with SMI compared to non-SMI offenders when controlling for demographics, condition of release, offense type, and condition of return (parole violation vs. new commitment). The median time for all SMI offenders to return to prison was 385 days versus 743 days for all non-SMI offenders, 358 days sooner ( p < .001). Implications of these findings are discussed.
Ethnographic Writing Is as Good as Ten Mothers
Authors: Jenkins Mercilee M.
Published: January 2010

Ethnography and ethnographic writing are celebrated as means of exploring and rendering our understandings of human interactions via creative modes of expression. The article stresses the importance of writing during all phases of ethnography from data collection to reporting. Specifically, the author seeks to demonstrate how ethnography and playwriting can work together as both research and art. The author has been writing plays inspired by ethnographic research and getting them produced at small professional theatres for about 20 years and hopes to pass on some of what she has learned in the form of general principles. Excerpts from her latest play, The Fabulous Ruins of Detroit (2009), are included to illustrate points addressed in the article.
The Fabulous Ruins of Detroit: Selected Excerpts
Authors: Jenkins Mercilee M.
Published: January 2010

Excerpts are presented from each of three acts of The Fabulous Ruins of Detroit, a play that tells the story of a Black man and a White woman, who grow up in the same neighborhood, survive the 1967 riots/rebellion together, and meet again 40 years later. Ruins is based on the author’s autoethnography, oral histories, archival materials, and the imaginative re-creation of actual events.
Improving Newspapers’ Economic Prospects by Augmenting Their Contributions to Democracy
Authors: Entman Robert M.
Published: January 2010

Newspapers confront an acute dilemma: how to give citizens more of what they need in a democracy—more than citizens now know enough to demand in the marketplace. The more news production strays from the core function of enhancing democracy, the more potential consumers learn they have little reason to invest their free time consuming serious political journalism. So they don’t, and newspapers and the stock market continue redirecting their resources. To counter this, industry observers have been urging non-profit business models. Yet even in this scenario, maintaining their watchdog function requires newspapers to support staffs large enough to investigate the powerful. Therefore, this essay argues, even a non-profit newspaper industry should still pursue mass audiences. Building on a synthesis of scholarly findings, this article suggests ways of doing political journalism that respond to changing audience interests and ever-growing alternatives to traditional daily newspapers—while remaining true to the higher ideals of watchdog journalism. To illustrate pitfalls of current practice and benefits of innovation it analyzes news about global warming.
Editorial: Leukocyte trafficking and matrix metalloproteinase-8 in obliterative bronchiolitis
Authors: Grasemann Hartmut , Ratjen Felix
Published: January 2010

The importance of MMP-8 in the pathogenesis of transplant associated obliterative bronchiolitis is discussed.
Editorial: Quality versus quantity in myeloid infection by a herpesvirus: more than one way to skin the CCAAT?
Authors: Lukac David M
Published: January 2010

KSHV and other herpes viruses use redundant proteins and miRNAs to subvert the host cell.
Hemopexin: anti-inflammatory, pro-inflammatory, or both?
Authors: Bakker W W , Melgert B N , Faas M M
Published: January 2010

Comment on Fink Editorial: premature to label Hx as an anti-inflammatory molecule? Are we ignoring its potential pleiotropic nature?
Editorial: Glycyrrhizin against multi-resistant bacteria?
Authors: Steinstraesser Lars , Schubert Cornelius , Jacobsen Frank , Al-Benna Sammy
Published: January 2010

A remarkable contribution towards new leads for the fight against multiresistant microorganisms is discussed.
Editorial: Memory CD8 T cells now join “Club 21”
Authors: Tagaya Yutaka
Published: January 2010

The role of IL-21 on CD8 memory T cells is discussed regarding the relevance of emerging data.

In this volume, Nguyen and Weng [1] show an intriguing study in which they observed an antagonizing effect by IL-21 on the IL-7- or IL-15-driven expansion of CD28− nonfunctional memory CD8 T cells and thereby, proposed a new role for IL-21 to keep the memory pool fresh and competent. I will summarize previous studies and discuss the recent advancement in this context.
Extraction of structure-based geoelectric models by hybrid genetic algorithms
Authors: Akça Irfan , Basokur Ahmet Tuğrul
Published: January 2010

A major difficulty in electrical resistivity imaging is the identification of the lithologic units, especially in the sedimentary environments. The geologic interpretation generally is realized by visual inspection of the final resistivity section. Although sharp boundary inversion techniques based on a local linearization could allow the delineation of interfaces between geologic units, these techniques will succeed only if an initial model already close to the best solution is available. Stochastic algorithms might localize a point around the global minimum of the misfit function; however, they are not efficient at finding the precise solution. For this reason, our previously published hybrid genetic algorithms, derived from evolution theories, are used to verify structure-based models. The geometric parameters are defined by thickness values of the lithologic units at control points distributed along the horizontal axis. A zero thickness value indicates the nonexistence of a certain unit at the corresponding con-trol point. An unstructured grid composed of irregular triangles is constructed by the application of Delaunay triangulations to represent complicated structural boundaries. In addition, the computation time for the calculation of model response is reduced greatly by this strategy. Because the suggested parameterization reduces the number of unknown parameters to a few tens and the computation time for the model responses is reduced by the Delaunay triangulation, the implementation of hybrid genetic algorithms for 2D problems becomes possible. A huge number of models are generated randomly in the first generation (a population of parameters) and then updated in subsequent generations by the simulation of biological processes. The suggested algorithms consist of two computational phases. In the first stage, the physical property of each subsurface layer is represented by a distinct resistivity value. After some succeeding genera-tions, laterally varying resistivities within the same lithologic unit are permitted to simulate lateral changes in geologic conditions.
Autism in fiction and autobiography
Authors: Bates Gordon
Published: January 2010

Many memorable characters in Western culture could be viewed as having features of autism or Asperger syndrome. In spite of the familiarity of autistic stereotypes such as Star Trek‘s Mr Spock, more completely described characters with autism are still unusual. In recent years there has been a growing interest in autism, mirrored by an increase in depictions of autism in popular works of fiction and autobiography. In this article I will outline the issues that have preoccupied writers and the techniques they have used to demonstrate autistic difference. Some writers have illuminated aspects of the autistic triad of social impairment, abnormalities of language and need for sameness. Other writers have opened our eyes to the autistic world view in its strangeness and richness. Still more have started to examine prejudice, disability rights and the implications of an international autism community. As in other areas of mental health, literature can help inform, entertain and question our attitudes and values.
Medical professionalism in psychiatry
Authors: Bhugra Dinesh , Gupta Susham
Published: January 2010

The principles of primacy of patient welfare, patient autonomy and social justice are fundamental to medical and psychiatric professionalism. Medical professionalism is also about encouraging and celebrating good practice. As a set of values and behaviours on the one hand, and relationships with patients, carers and other stakeholders on the other, the implicit contract between psychiatry and society needs to be renegotiated regularly. Serious threats to medical professionalism in the past 30 years have led to the demoralisation of professionals. Learned helplessness and a perceived loss of autonomy have been recognised as important factors in the ‘loss’ of professionalism. Psychiatry as a profession needs to identify its core attributes, skills and competencies. Professionalism should allow individuals to set and maintain their own standards of care.
Understanding offenders with autism-spectrum disorders: what can forensic services do?
Authors: Murphy David
Published: January 2010

This commentary aims to support and elaborate on some of the specific issues raised by Dein & Woodbury-Smith. Although I agree with many of their comments, I believe that the role of neuropsychological and sensory impairments, as well as dysfunctional coping strategies among individuals with an autism-spectrum disorder who offend, need to be expanded from a psychological perspective. In my experience, the assessment of these factors plays a crucial role in guiding opinions on mental capacity, individual interventions, risk assessment and management. Elements of psychopathy in autism also require clarification. It could be argued that by understanding these issues, any attempts at social inclusion and preventing offending will be more successful.
Revision of the classification of mental disorders in ICD–11 and DSM–V: work in progress
Authors: Sartorius Norman
Published: January 2010

This editorial summarises the work done to prepare ICD–11 and DSM–V (which should be published in 2015 and 2013 respectively). It gives a brief description of the structures that have been put in place by the World Health Organization and by the American Psychiatric Association and lists the issues and challenges that face the two organisations on their road to the revisions of the classifications. These include dilemmas about the ways of presentation of the revisions (e.g. whether dimensions should be added to categories or even replace them), about different versions of the classifications (e.g. the primary care and research versions), about ways to ensure that the best of evidence as well as experience are taken into account in drafting the revision and many other issues that will have to be resolved in the immediate future.
Metallomics: Guidelines for terminology and critical evaluation of analytical chemistry approaches (IUPAC Technical Report)
Authors: Lobinski Ryszard , Becker J. Sabine , Haraguchi Hiroki , Sarkar Bibundhendra
Published: January 2010

Definitions for the terms "metallome" and "metallomics" are proposed. The state of the art of analytical techniques and methods for systematic studies of metal content, speciation, localization, and use in biological systems is briefly summarized and critically evaluated.
NICU Nursing for the 21st Century
Authors: McCann Debra , Kenner Carole , Boykova Marina
Published: January 2010

The role of the neonatal nurse continues to evolve. Earlier identified as technicians, contracted clinicians, advocates, and surrogate parents, today's neonatal intensive care unit (NICU) nurse plays a much larger role as a key part of the health-care team. Nursing budgets in many NICUs account for 25% to 30% of costs, which has forced nursing staff to clarify their role in the NICU and justify their value at the bedside. Despite years of debate, confusion still exists about the role of nursing, which rarely is defined clearly by job descriptions. This article explores the role of the NICU nurse as part of an interdisciplinary team.
Neonatal Nurse Practitioners in Interdisciplinary Care of High-risk Infants
Authors: Parker Leslie A.
Published: January 2010

Neonatal nurse practitioners (NNPs) have become an integral component of interdisciplinary care in the neonatal intensive care unit (NICU). They provide competent and cost-effective care for infants both in the NICU and following discharge. Although most NNPs care for infants in level III NICUs, they also provide other services, including functioning as first responders for high-risk deliveries and emergency services in level I and II nurseries and caring for infants in outpatient settings such as high-risk newborn follow-up clinics and pediatricians’ offices. By providing holistic, comprehensive, and consistent care to high-risk infants, NNPs facilitate optimal care to vulnerable infants both in the hospital and following discharge. The functions and achievements of NNPs are intrinsically bound to their collaborative relationships with neonatologists and other health-care practitioners. Collaboration is imperative for providing safe, optimal care; decreasing medical errors; developing evidence-based guidelines; facilitating interdisciplinary research; and educating various health-care practitioners. NNPs can serve as role models for interdisciplinary care of high-risk infants that crosses conventional role boundaries. This article discusses the history, role, and unique contributions of NNPs.
Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals With ASDs: A Consensus Report
Authors: Buie Timothy , Campbell Daniel B. , Fuchs George J. , Furuta Glenn T. , Levy Joseph , VandeWater Judy , Whitaker Agnes H. , Atkins Dan , Bauman Margaret L. , Beaudet Arthur L. , Carr Edward G. , Gershon Michael D. , Hyman Susan L. , Jirapinyo Pipop , Jyonouchi Harumi , Kooros Koorosh , Kushak Rafail , Levitt Pat , Levy Susan E. , Lewis Jeffery D. , Murray Katherine F. , Natowicz Marvin R. , Sabra Aderbal , Wershil Barry K. , Weston Sharon C. , Zeltzer Lonnie , Winter Harland
Published: January 2010

Autism spectrum disorders (ASDs) are common and clinically heterogeneous neurodevelopmental disorders. Gastrointestinal disorders and associated symptoms are commonly reported in individuals with ASDs, but key issues such as the prevalence and best treatment of these conditions are incompletely understood. A central difficulty in recognizing and characterizing gastrointestinal dysfunction with ASDs is the communication difficulties experienced by many affected individuals. A multidisciplinary panel reviewed the medical literature with the aim of generating evidence-based recommendations for diagnostic evaluation and management of gastrointestinal problems in this patient population. The panel concluded that evidence-based recommendations are not yet available. The consensus expert opinion of the panel was that individuals with ASDs deserve the same thoroughness and standard of care in the diagnostic workup and treatment of gastrointestinal concerns as should occur for patients without ASDs. Care providers should be aware that problem behavior in patients with ASDs may be the primary or sole symptom of the underlying medical condition, including some gastrointestinal disorders. For these patients, integration of behavioral and medical care may be most beneficial. Priorities for future research are identified to advance our understanding and management of gastrointestinal disorders in persons with ASDs.
Gate Stack Reliability of High-Mobility 4H SiC Lateral MOSFETs with Deposited Al2O3 Gate Dielectric
Authors: Lichtenwalner Daniel J , Misra Veena , Dhar Sarit , Ryu Sei-Hyung , Agarwal Anant
Published: January 2010

Lateral nMOSFETs have been fabricated on 4H-SiC utilizing deposited dielectrics and gate-last processing. A bi-layer dielectric was utilized consisting of thin nitrided SiO2 covered by 25nm of Al2O3 deposited using atomic layer deposition. Field-effect mobility and threshold voltage (VT) were found to vary with SiC nitric oxide (NO) anneal temperature. High peak mobility values of 106 cm2/V·s were obtained, with a corresponding VT of 0.8 V, using an 1175 °C 20 min NO anneal of the SiC before Al2O3 deposition. Constant voltage stressing (CVS) of the gate (3 MV/cm) for 1000s induces a VT increase of only 0.12 V for the devices stressed at RT, whereas a VT shift of 0.34 V occurs for devices stressed at 150 °C. Heating unstressed devices to 200 °C reveals a stable VT with temperature. Negative charge in the gate region allows for the attainment of positive VT, while VT stability does not suffer.
ZnO-based MESFET Devices
Authors: Grundmann Marius , Frenzel Heiko , Lajn Alexander , von Wenckstern Holger , Schein Friedrich , Lorenz Michael
Published: January 2010

We present transistors and inverters based on the MESFET principle. The channel consists of thin ZnO:Mg thin films on sapphire, deposited with pulsed laser deposition. The ohmic source and drain contacts are formed with sputtered gold. The Schottky gate electrode is formed by metal oxides providing high barrier height and a reliable contact. The voltage swing of our inverters is superior to any other reported oxide devices. Annealing studies show that our devices withstand temperatures up to 150°C, partly improving during annealing.
Cyan electroluminescence from n-ZnO/i-CdZnO/p-Si heterojunction diodes
Authors: Li Lin , Yang Zheng , Liu Jianlin
Published: January 2010

n-ZnO/i-CdZnO thin film was grown on p-type Si substrate by plasma-assisted molecular-beam epitaxy (MBE). Rectifying I-V curves show typical diode characteristics. Cyan electroluminescence emissions at around 473 nm were observed when the diodes were forward-biased at room temperature. The emission intensity increases with the increase of the injection current. Room temperature photoluminescence verifies the electroluminescence emissions come from CdZnO layer.
Electrical and thermal stress analysis of In2O3-Ga2O3-ZnO thin-film transistors
Authors: Fujii Mami , Maruyama Tomoki , Horita Masahiro , Uchiyama Kiyoshi , Jung Ji Sim , kwon jang yeon , Uraoka Yukiharu
Published: January 2010

Degradation of In2O3-Ga2O3-ZnO (IGZO) thin-film transistors (TFTs)) was studied. We evaluated degradation caused by applying gate voltage and drain voltage stress. A parallel shift of the transfer curve was observed under gate voltage stress. Joule heating caused by the drain current was observed. We tried to reproduce this degradation of the transfer curve change by device simulation. When we assumed the trap level as the density of state (DOS) model and increased two kinds of trap density, we obtained properties that show the same trends as the experimental results. We concluded that two degradation mechanisms occur under gate and drain voltage stress conditions. And then, we tried to improve the TFT characteristics using high pressure water vapor (HPV) annealing. We also found that the cooling conditions after HPV annealing affect the IGZO TFT characteristics.
MBE-grown NiyMg1-yO and ZnxMg1-xO Thin Films for Deep Ultraviolet Optoelectronic Applications
Authors: Mares Jeremy West , Boutwell Ryan Casey , Falanga Matthew Thomas , Scheurer Amber , Schoenfeld Winston Vaughan
Published: January 2010

We report on the heteroepitaxial growth of high-quality single crystal cubic ZnxMg1-xO and NiyMg1-yO thin films by radio frequency oxygen plasma-assisted molecular beam epitaxy (RF-MBE). Film compositions over the ranges x = 0 to x = 0.65 and y = 0 to y = 1 have been grown on lattice-matched MgO (100) and characterized optically, morphologically, compositionally, and electrically. Both of these ternary materials are shown to have bandgaps which vary directly as a function of transition metal (Ni or Zn) concentration. Optical transmission measurements of NiyMg1-yO show the bandgap to shift continuously over the approximate range 3.5 eV (for NiO) to 4.81 eV (for y=0.075). Similarly, the bandgap of cubic ZnxMg1-xO is shifted from about 4.9 eV (for x = 0.65) to 6.25 eV (for x=0.12). Films exhibit good morphological quality and typical roughness of NiyMg1-yO films is 5 Å while that of ZnxMg1-xO is less than 15 Å, as measured by atomic force microscopy (AFM). X-ray diffraction (XRD) is employed to confirm crystal orientation and to determine the films' lattice constants. Film compositions are interrogated by Rutherford Backscattering (RBS) and electrical characterization is made by room-temperature Hall measurements.
Room Temperature Ferromagnetism in Powder Form of Sn1-xCrxO2 (x = 0.01, 0.02, 0.03, 0.04 and 0.05) Solid Solution
Authors: Xu Kun , Izumi Mitsuru , Yanagisawa Osami , Ida Tetsuya
Published: January 2010

Structural and magnetic properties were investigated in the mixed powders of Sn1-xCrxO2 (x = 0.01, 0.02, 0.03, 0.04 and 0.05) in nominal composition. The lattice parameter observed in (110) x-ray diffraction indicates two step changes with increasing Cr content. The occupation of Cr ion at the interstitial position leads to elongation of the lattice parameter for x = 0.01 to x =0.03. Then, the Cr3+ ions are remarkably substituted into the Sn4+ ion site for x = 0.04 to x = 0.05, which results in shortening of the lattice. The lattice parameters for x = 0.01 and 0.02 are larger than x = 0.03 to 0.05. The room temperature ferromagnetism appeared in the sample with x = 0.01 and reaches maximum at the doping rate of x = 0.02; while the magnetization decreases for x > 0.02 was observed. Present study clearly shows the existence of correlation between appearance of ferromagnetism and the structural change.
Kinetics and Mechanism of Formation of GaN from β-Ga2O3 by NH3
Authors: Sakai Toshiki , Kiyono Hajime , Shimada Shiro
Published: January 2010

Nitridation of β-Ga2O3 to GaN in an atmosphere of NH3/Ar was investigated from the view points of kinetic results by thermogravimetric analysis (TGA) and microstructural observation. TGA and X-ray powder diffraction results showed that the nitridation of Ga2O3 to GaN starts at about 650°C and decomposition of GaN formed occurs from 870°C. Isothermal TGA results showed that the nitridation proceeds linearly with time at 800 – 1000°C. Microstructural observation of the samples nitrided at 800°C showed that fine GaN particles (∼50 nm size) deposit on surfaces of Ga2O3 particles at an early stage, and the deposits grow with progress of the nitridation.
Low-resistance Ohmic Contacts to N-face p-GaN for the Fabrication of Functional Devices
Authors: Han Seung-Cheol , Kim Jae-Kwan , Kim jun Young , Kwak Joon Seop , Kim Kangho , Kim Jong Kyo , Schubert E. , Kim Kyoung-Kook , Lee Ji-Myon
Published: January 2010

The electrical properties of Ni-based ohmic contacts N-face p-type GaN are presented. The specific contact resistance of N-face p-GaN exhibits a liner decrease from 1.01 × cm2 to 9.05 × 10-3 Ω cm2 for the as-deposited and the annealed Ni/Au contacts, respectively, with increasing annealing temperature Furthermore, the specific contact resistance could be decreased by four orders of magnitude to 1.03 × 10-4 Ω cm2 as a result of surface treatment using an alcohol-based (NH4)2S solution. The depth profile data measured by the intensity of O1s core peak in the x-ray photoemission spectra showed that the alcohol-based (NH4)2S treatment was effective in removing of the surface oxide layer of GaN. In addition, a Ga 2p core-level peak showed a red-shift of binding energy by 0.3 eV by alcohol-based (NH4)2S treatment, indicating that the surface Fermi level was shifted toward the valence-band edge. Thus, the low ohmic contact behavior observed in our treated sample might be explained in terms of the removal of the oxide layer and reducing the barrier heights by reduced band-bending effect.
Recent Advances in Wide Bandgap Semiconductor Biological and Gas Sensors
Authors: Pearton S.J. , Ren F. , Wang Yu-Lin , Chu B. H. , Chen K. H. , Chang C. Y. , Lim Wantae , Lin Jenshan
Published: January 2010

There has been significant recent interest in the use of surface-functionalized thin film and nanowire wide bandgap semiconductors, principally GaN, InN, ZnO and SiC, for sensing of gases, heavy metals, UV photons and biological molecules. For the detection of gases such as hydrogen, the semiconductors are typically coated with a catalyst metal such as Pd or Pt to increase the detection sensitivity at room temperature. Functionalizing the surface with oxides, polymers and nitrides is also useful in enhancing the detection sensitivity for gases and ionic solutions. The wide energy bandgap of these materials make them ideal for solar-blind UV detection, which can be of use for detecting fluorescence from biotoxins. The use of enzymes or adsorbed antibody layers on the semiconductor surface leads to highly specific detection of a broad range of antigens of interest in the medical and homeland security fields. We give examples of recent work showing sensitive detection of glucose, lactic acid, prostate cancer and breast cancer markers and the integration of the sensors with wireless data transmission systems to achieve robust, portable sensors.
A novel functionalization of AlGaN/GaN-pH-Sensors for DNA-sensors
Authors: Linkohr Stefanie , Schwarz S. U. , Krischok S. , Lorenz P. , Nakamura T. , Polyakov V. , Cimalla V. , Nebell C. , Ambacher O.
Published: January 2010

AlGaN/GaN pH sensitive devices were functionalized and passivated for the use as selective bio-sensors. For the passivation, a multilayer of SiO2 and SiNx is proposed, which stabilizes the pH-sensor, is biocompatible and has no negative impact on the following bio-functionalization. The functionalization of the GaN-surface was achieved by covalent bonding of 10-amino-dec-1-ene molecules by a photochemical process. After two different surface preparations islands of TFAAD are growing on the sensor surface by exposure with UV-light. In dependence on the surface pre-treatment and the illumination wavelength the first monolayer is completed after 3 h or 7 h exposure time dependent on the pre-treatment and illumination wavelength. Further exposure results in thicker films as a consequence of cross polymerization. The bonding to the sensor surface was analyzed by X-ray photoelectron spectroscopy, while the thickness of the functionalization was determined by atomic force microscopy scratching experiments. These functionalized devices based on the pH-sensitive AlGaN/GaN ISFET will establish a new family of adaptive, selective biomolecular sensors such as selective, reusable DNA sensors.
Short-Wavelength Intersubband Light Emission from Optically Pumped GaN/AlN Quantum Wells
Authors: Paiella Roberto , Driscoll Kristina , Liao Yitao , Bhattacharyya Anirban , Zhou Lin , Smith David J. , Moustakas Theodore D.
Published: January 2010

Due to their large conduction-band offsets, GaN/Al(Ga)N quantum wells are currently the subject of extensive research efforts aimed at extending the spectral range of intersubband optoelectronic devices towards shorter and shorter wavelengths. Here we report our recent measurement of optically pumped intersubband light emission from GaN/AlN quantum wells at the record short wavelength of about 2 μm. Nanosecond-scale optical pulses are used to resonantly pump electrons from the ground states to the second excited subbands, followed by radiative relaxation into the first excited subbands. The intersubband origin of the measured photoluminescence is confirmed via an extensive study of its polarization properties and pump wavelength dependence.
CH2 group migration between the H-terminated 2×1 reconstructed {100} and {111} surfaces of diamond
Authors: Richley James C. , Harvey Jeremy N. , Ashfold Mike N.R.
Published: January 2010

Various possible routes for the migration of a CH2 group between the H-terminated 2×1 reconstructed {100} surface and the H-terminated {111} surface of diamond have been explored using a hybrid quantum mechanical/molecular mechanical method. The calculated energies suggest that movement of such surface bound species across step edges should be a facile process under typical diamond growth conditions, and that such migrations are significant contributors to the observed morphologies of diamond grown by chemical vapor deposition methods.
Pressure-induced Structural Phase Transition of Carbon Nanotubes into New Nanostructured Carbon Solids
Authors: Sakurai Masahiro , Saito Susumu
Published: January 2010

We study pressure-induced structural phase transition of carbon nanotubes using the constant-pressure tight-binding molecular-dynamics simulation. The systems studied are nanotube bundles composed of (6,6) armchair nanotube and/or (7,4) chiral nanotube, which are reported to be the nanotubes relatively abundant in experimentally purified sample. We find that the nanotube bundles transforms into a new phase that consist of graphitic ribbons and diamond blocks, “graphitic nanoribbon solid”. It is also found that sp3-rich phases obtained from the armchair nanotubes possess an anisotropic network and have high hardness which is comparable to that of cubic diamond. In the case of the bundles containing chiral nanotubes, on the other hand, amorphous diamond phase is obtained. Based on the local-density approximation in the density-functional theory, we also investigate the energetics and electronic structure of some of new carbon phases obtained in the molecular-dynamics study.
Flexible and Transparent SWCNT Electrodes for Alternating Current Electroluminescence (ACEL) Devices
Authors: Schrage Christian , Kaskel Stefan
Published: January 2010

The application of transparent single-walled carbon nanotube (SWCNT) electrodes in rigid and flexible alternating current electroluminescence (ACEL) devices is demonstrated. SWCNT thin film electrodes (50 – 160 nm) were made using a spray-coating process suitable for adjusting transparency and sheet resistance. The emission intensity was as high as for indium tin oxide (ITO) based ACEL devices with transparencies comparable to ITO coated polymer slides.
The Effect of Ion Delivery on Polypyrrole Strain and Strain Rate under Elevated Temperature
Authors: Keng Yenmei , Pillai Priam Vasudevan , Hunter Ian W
Published: January 2010

Conducting polymers can act as actuators when an electrochemical stimulus causes the materials to undergo volumetric changes. Ion flux into the polymer causes volumetric expansion and ion outflow causes contraction. Polypyrrole is an attractive actuator material due to its ability to generate up to 30 MPa active stress and 10% to 26% maximum strain with voltage supply lower than 2 V. The polymer’s mechanical performance depends upon the solvent used and the dominating ion species. In this study, we used 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6) to characterize the effect of temperature increase on ion flow and how it contributes to strain and maximum strain rate of polypyrrole. In this solvent, the cation BMIM+ diffuses in and out of the polymer under applied voltage to cause strain changes. For approximately each increment of 10°C from 27°C to 83°C, isotonic tests were done with +/-0.8 V square pulses, using a custom built device that is capable of performing temperature controlled dynamic mechanical analyses and electrochemistry simultaneously. Results showed that, independent of voltage polarity, from 27 to 83°C the strain increased from 0.4% to 2.0%. Both the maximum charge and strain rate rates increased with temperature, and were higher at positive voltage than at negative voltage throughout the same temperature range. Positive voltage caused the maximum strain rate to increase exponentially from 0.1 %/s to 0.67 %/s, while negative voltage caused it to increase more linearly from 0.06 %/s to 0.23 %/s. The results suggest that the increase in strain resulted from the charge delivered to the polymer in higher quantities at higher temperature. Furthermore, BMIM+ ions are expelled faster than those being attracted in to the polymer, perhaps due to the ions preferentially remaining in the bulk solution. As the temperature increased, the ionic mobility increased and as a result, BMIM+ ions are expelled back into the solvent even faster.
Thin Film Bulk Acoustic Wave Resonators for Continuous Monitoring in the Physical, Chemical and Biological Realms
Authors: Ashley Greg , Luo Jack , Kirby Paul , Butler Timothy , Cullen David
Published: January 2010

A transducer that can act as a highly sensitive and reliable universal sensor capable of detecting and continuously monitoring changes in the physical, chemical and biological domains is a potentially useful scientific tool. The Thin Film Bulk Acoustic Wave Resonator (FBAR) is a microwave device that is becoming increasingly recognised as a universal transduction platform with the added advantage of potential integration into CMOS architecture and array-like formats. This work shows preliminary results on FBAR where a continuous monitoring arrangement demonstrated the capability of FBAR to respond to changes in physical parameters such as temperature and light levels, the work goes on further to show the ability of FBAR to respond to changes in humidity in a gas flow and can have sensitivity increased with the addition of hygroscopic polymers on its surface and finally how FBAR can be adapted to act as a biosensor in the form of an immunosensor with sensitivity some orders of magnitude greater than traditional lower frequency bulk acoustic wave platforms.
Thickness-Dependant Electrical Characteristics of Nitrogen-Doped Polycrystalline 3C-SiC Thin Films Deposited by LPCVD
Authors: Lei Man I , Lee Te-Hao , Mehregany Mehran
Published: January 2010

The effect of film thickness on the electrical resistivity of heavily-nitrogen-doped polycrystalline SiC (poly-SiC) thin films is investigated. The resistivity of poly-SiC thin films decreases by a factor of ˜7 for thickness increasing from 100 nm-thick to 1.78 μm-thick; the resistivity begins to stabilize as thickness approaches 1 μm. The increased resistivity for the thinner films is shown to be related to the grain boundary effect. Secondary ion mass spectrometry indicates a nitrogen concentration of 9×1020 atoms/cm3 in the films. However, Hall measurements reveal that only 45% of the dopants are electrically active in the 100 nm-thick film. The percentage of active dopants rises to 80% when film thickness increases to 680 nm. From the studies of surface roughness and microstructure, it is seen that small grains are formed at the initial stage of deposition, which then grow into larger columnar grains as film thickness increases. The presence of a large density of grain boundaries and limited grain growth for the very thin films contribute to increased electrical resistivity from increased trapped mobile carriers and reduced carrier mobility. The free carrier trapping phenomenon can further be observed in the temperature-dependence of resistance measurement.
Polycrystalline Silicon-Germanium Electrode Contact Technology Improvement for MEMS Applications
Authors: Claes Gert , Severi Simone , Decoutere Stefaan , Celis Jean-Pierre , Witvrouw Ann
Published: January 2010

Poly-SiGe has quite some potential as structural MEMS layer for CMOS-MEMS integration. However, the contact resistance between SiGe MEMS and top CMOS metal should be low to avoid parasitic effects that would reduce the system performance. In this paper, a new and simple approach is proposed to achieve a low contact resistance between a top CMOS interconnect and a boron doped poly-SiGe MEMS layer deposited at 450 °C. The use of a 20 nm soft sputter etch in combination with a Ti-TiN (5-10 nm) interlayer results in a contact resistivity of 6.2 ± 0.4 × 10-7Ωcm2that is lower than previously reported. The uniformity of the contact resistivity across the wafer is also better than the state-of-the-art value.
Densely-Packed Microbowl Array with Balanced Dielectrophoretic Forces for Single-Cell Microarray
Authors: Im Maesoon , Kim Dong-Haan , Lee Joo-Hyung , Yoon Jun-Bo , Choi Yang-Kyu
Published: January 2010

In this paper, we demonstrate a perfectly-ordered microbowl array with balanced dielectrophoresis (DEP) for a high-throughput single-cell analysis. In order to fabricate well-ordered microbowl array in a large area, we utilized three-dimensional diffuser lithography for photoresist mold and nickel electroplating technique for final microbowl structures on a silicon substrate. Single microbowl has six sharp apexes surrounding the microbowl perimeter. Each microbowl has a diameter of 10 μm, and a height of 9 μm, which can be controllable by patterns on mask and lithography conditions. To investigate feasibility for application to the microbowl array as a single-cell microarray, we used latex beads of 6.4 μm in an average diameter to be captured by dielectrophoretic force. The nickel microbowl array densely packed with a hexagonal geometry played as a bottom electrode, and an ITO-coated glass covered the nickel microbowl array as a top electrode while keeping a uniform gap between two electrodes. After injecting solution containing latex beads through the gap, we applied an AC signal (2 VPP, 1 MHz) between two electrodes to induce high electric field near the sharp apexes of the single microbowl. A negative DEP trap is formed at the center of the single microbowl with balanced DEP force from the six apexes. The experimental result shows that injected latex beads had been successfully and uniformly aligned and trapped at the microbowl array sustained by negative DEP.
Migration of Marrow Stromal Cells in Response to Sustained Release of Stromal-Derived Factor-1α from Poly(lactide ethylene oxide fumarate) Hydrogels
Authors: He Xuezhong , Ma Junyu , Jabbari Esmaiel
Published: January 2010

Stromal derived factor-1α (SDF-1α) is an important chemokine in stem cell trafficking and plays a critical role in the homing, osteogenesis as well as angiogenesis of bone marrow stromal (BMS) cells. The objective of this work was to investigate the release characteristics of SDF-1α from the degradable poly(lactide ethylene oxide fumarate) (PLEOF) hydrogels and to determine the effect of sustained release of SDF-1α on migration of BMS cells. Three PLEOF macromers with PLA content of 6, 9, and 24 by weight were synthesized by condensation polymerization. The cumulative amount of biologically-active SDF-1α released from the PLEOF hydrogels after 3 weeks was between 20-25% of the initial loading and was independent of PLA/PEG ratio in the hydrogel. The migration of BMS cells in response to the time-release SDF-1α from PLEOF hydrogels closely followed the release kinetics of SDF-1α from the hydrogels. Results demonstrate that migration of BMS cells was significantly increased by the sustained release of SDF-1α from PLEOF hydrogels.
Functionalization of Nanofibrous Spiral Structured Scaffolds for Bone Tissue Engineering
Authors: Wang Junping , Yu Xiaojun
Published: January 2010

In the previous studies, we have successfully developed a novel spiral structured nanofibrous scaffolds with improved osteoconductivity for bone tissue engineering. The spiral structure design facilitates the nutrient transport and waste removal, and allows uniform cellular growth and distribution within the scaffolds, thus enhanced the bioactivity of the scaffolds. In this chapter, HAP and BMP-2 were incorporated within the nanofibrous spiral scaffolds in order to enhance the osteoinductivity of the established system. The effect of the blending materials was evaluated through cell proliferation, cell differentiation of human osteoblast cells seeded on the scaffolds and cultured for 4 and 8 days. The results has demonstrated that the functionalization of PCL nanofibrous spiral scaffolds leads to higher ALP expression level and increased amount of mineralization level however lower cell proliferation rate.
Removal and successful re-implantation of a customized interpositional knee device following an early postoperative infection: A case report
Authors: Koeck Franz , Rath Bjoern , Springorum Hans-Robert , Tingart Markus , Grifka Joachim , Beckmann Johannes
Published: January 2010

We report the first case of early postoperative infection after a medial hemiarthroplasty of the knee with a customized ConforMIS iForma™ interpositional device. The infection was treated successfully by revision surgery with implant removal and antibiotic therapy. Despite the additional diagnosis of rheumatoid arthritis that did not affect the treated knee, the preservation of bony and ligamentous structures enabled a successful re-implantation of another iForma™ implant 9 months later with good clinical results at follow-up examination 1 year postoperatively. This is very much in contrast to the extensive and complex revision surgery, with significant bone loss, in patients with infected unicompartmental or total knee arthroplasties. The iForma™ device may be an alternative treatment option in early and moderate unicompartmental arthritis of the knee, with easy revision with the same type of implant in the rare case of infection.