bluuebunny/crossref_metadata_2025 huggingface dataset:
Growing backwards: an inverted role for the shrimp ortholog of vertebrate myostatin and GDF11
Authors: De Santis Christian , Wade Nicholas M. , Jerry Dean R. , Preston Nigel P. , Glencross Brett D. , Sellars Melony J.
Published: July 2011

Myostatin (MSTN) and growth differentiation factor-11 (GDF11) are closely related proteins involved in muscle cell growth and differentiation as well as neurogenesis of vertebrates. Both MSTN and GDF11 negatively regulate their functions. Invertebrates possess a single ortholog of the MSTN/GDF11 family. In order to understand the role of MSTN/GDF11 in crustaceans, the gene ortholog was identified and characterized in the penaeid shrimp Penaeus monodon. The overall protein sequence and specific functional sites were highly conserved with other members of the MSTN/GDF11 family. Gene transcripts of pmMstn/Gdf11, assessed by real-time PCR, were detected in a variety of tissue types and were actively regulated in muscle across the moult cycle. To assess phenotypic function in shrimp, pmMstn/Gdf11 gene expression was downregulated by tail-muscle injection of sequence-specific double-stranded RNA. Shrimp with reduced levels of pmMstn/Gdf11 transcripts displayed a dramatic slowing in growth rate compared with control groups. Findings from this study place the MSTN/GDF11 gene at the centre of growth regulation in shrimp, but suggest that, compared with higher vertebrates, this gene has an opposite role in invertebrates such as shrimp, where levels of gene expression may positively regulate growth.
Hearing and morphological specializations of the mojarra (Eucinostomus argenteus)
Authors: Parmentier Eric , Mann Kenneth , Mann David
Published: July 2011

The air-filled swimbladder acts as an acoustic amplifier for some fish by converting sound pressure into particle motion, which is transmitted to the inner ear. Here, we describe in detail the specialized connection between the swimbladder and ear in the mojarra, as well as a modified cone on the anal fin in which the posterior end of the swimbladder sits. Hearing tests show the mojarra has better hearing sensitivity than other species of fish without a connection. However, mojarras do not seem to use this adaptation for communication. Furthermore, the inclined position of the swimbladder may help the fish to catch their prey more easily, as the swimbladder will be horizontal when they are picking up benthic prey.
The Trade Effects of Endogenous Preferential Trade Agreements
Authors: Egger Peter , Larch Mario , Staub Kevin E , Winkelmann Rainer
Published: July 2011

Structural new trade theory models have never been used to evaluate and quantify the role of preferential trade agreement (PTA) membership for trade in a way which is consistent with general equilibrium. Apart from filling this gap, the present paper aims at delivering an empirical model which takes into account both that PTA membership is endogenous and that the world matrix of bilateral trade flows contains numerous zero entries. These features are treated in an encompassing way by means of (possibly two-part) Poisson pseudo-maximum likelihood estimation with endogenous binary indicator variables in the empirical model. (JEL F11, F13, F15)
Do Child Tax Benefits Affect the Well-being of Children? Evidence from Canadian Child Benefit Expansions
Authors: Milligan Kevin , Stabile Mark
Published: July 2011

We exploit changes in child benefits in Canada to study the impact of family income on child and family well-being. Using variation in child benefits across province, time, and family type, we study outcomes spanning test scores, mental health, physical health, and deprivation measures. The findings suggest that child benefit programs had significant positive effects on test scores, maternal health, and mental health, among other measures. We find strong and interesting differences in the effects of benefits by child sex: benefits have stronger effects on educational outcomes and physical health for boys, and on mental health outcomes for girls. (JEL I12, I31, I38, J13)
Public-Place Smoking Laws and Exposure to Environmental Tobacco Smoke (ETS)
Authors: Carpenter Christopher , Postolek Sabina , Warman Casey
Published: July 2011

Public-place smoking restrictions are the most important non-price tobacco control measures worldwide, yet surprisingly little is known about their effects on exposure to environmental tobacco smoke (ETS). We study these laws in Canada using data with questions about respondents' ETS exposure in public and private places. In fixed effects models we find these laws had no effects on smoking but induced large and statistically significant reductions in public-place ETS exposure, especially in bars and restaurants. We do not find significant evidence of ETS displacement to private homes. Our results indicate wide latitude for health improvements from banning smoking in public places. (JEL D12, H75, I12, I18, Q51)
A's from Zzzz's? The Causal Effect of School Start Time on the Academic Achievement of Adolescents
Authors: Carrell Scott E , Maghakian Teny , West James E
Published: July 2011

Recent sleep research finds that many adolescents are sleep-deprived because of both early school start times and changing sleep patterns during the teen years. This study identifies the causal effect of school start time on academic achievement by using two policy changes in the daily schedule at the US Air Force Academy along with the randomized placement of freshman students to courses and instructors. Results show that starting the school day 50 minutes later has a significant positive effect on student achievement, which is roughly equivalent to raising teacher quality by one standard deviation. (JEL I23, J13)
Metrological traceability in clinical biochemistry
Authors: White Graham H
Published: July 2011

True and precise routine measurements of quantities of clinical interest are essential if results are to be optimally interpreted for patient care. Additionally, results produced by different measurement procedures for the same measurand must be comparable if common diagnostic decision values and clinical research findings are to be broadly applied. Metrology, the science of measurement, provides laboratory medicine with a structured approach to the development and terminology of reference measurement systems which, when implemented, improve the accuracy and comparability of patients' results. The metrological approach is underpinned by the concepts of common measurement units, traceability of measured values, measurement uncertainty and commutability. Where traceability to the International System of Units (SI units) is not yet realized for a measurand, result comparability may be achievable by other, less ideal, approaches. Measurements are the core activity of clinical laboratories, and clinical biochemists should ensure that patients' results are traceable to the highest available reference. This review introduces and illustrates the principles of metrological traceability, describes its critical importance to improving the quality of patients' results and highlights the need to actively promote traceability in clinical laboratories.
Institutional Contradictions and Loose Coupling: Postimplementation of NASA's Enterprise Information System
Authors: Berente Nicholas , Yoo Youngjin
Published: July 2011

Through a grounded analysis of the National Aeronautics and Space Administration (NASA's) enterprise information system (IS) implementation in the months immediately following the go-live, we show how NASA can be characterized as an institutionally plural organization, rife with diverse institutional logics, some consistent and some contradictory to each other. The enterprise system is introduced in accordance with the logic of managerial rationalism, but some of the institutional logics that organizational actors draw upon and reproduce contradict the logic of managerial rationalism in certain situations. In these situations, organizational actors loosely couple elements of their practices from the practices implied by the enterprise system, thus satisfying the demands associated with both institutional fields. We identify four generalizable forms of loose coupling that result from these institutional contradictions: temporal, material, procedural, and interpretive, and discuss their effects on both the system implementation and local practices. Further, we show how, through the use of institutional logics, researchers can identify fundamental institutional contradictions that explain regularities in the situated responses to enterprise system implementations—regularities that are consistently identified in the literature across a variety of organizational contexts.
Managing Emerging Infectious Diseases with Information Systems: Reconceptualizing Outbreak Management Through the Lens of Loose Coupling
Authors: Chen Yi-Da , Brown Susan A. , Hu Paul Jen-Hwa , King Chwan-Chuen , Chen Hsinchun
Published: July 2011

Increasing global connectivity makes emerging infectious diseases (EID) more threatening than ever before. Various information systems (IS) projects have been undertaken to enhance public health capacity for detecting EID in a timely manner and disseminating important public health information to concerned parties. While those initiatives seemed to offer promising solutions, public health researchers and practitioners raised concerns about their overall effectiveness. In this paper, we argue that the concerns about current public health IS projects are partially rooted in the lack of a comprehensive framework that captures the complexity of EID management to inform and evaluate the development of public health IS. We leverage loose coupling to analyze news coverage and contact tracing data from 479 patients associated with the severe acute respiratory syndrome (SARS) outbreak in Taiwan. From this analysis, we develop a framework for outbreak management. Our proposed framework identifies two types of causal circles—coupling and decoupling circles—between the central public health administration and the local capacity for detecting unusual patient cases. These two circles are triggered by important information-centric activities in public health practices and can have significant influence on the effectiveness of EID management. We derive seven design guidelines from the framework and our analysis of the SARS outbreak in Taiwan to inform the development of public health IS. We leverage the guidelines to evaluate current public health initiatives. By doing so, we identify limitations of existing public health IS, highlight the direction future development should consider, and discuss implications for research and public health policy.
How Do Product Users Influence Corporate Invention?
Authors: Chatterji Aaron K. , Fabrizio Kira
Published: July 2011

The extensive academic literature on innovation has long recognized product users as a potentially important source of ideas. Although prior work has primarily focused on understanding the unique motivations and knowledge that allow users to generate their own innovations, we extend existing theory to investigate the contribution of users to corporate invention. We draw on the knowledge-based view of the firm, evolutionary theory, and the user innovation literature to theorize that corporate inventions that integrate user knowledge will be of greater importance, contribute to a broader set of follow-on technologies, and occur earlier in the product life cycle than other corporate inventions do. We test these propositions with a large data set of medical device inventions. We find support for our predictions and discuss the implications of our results for the theoretical and empirical literature on organizational innovation.
The Effect of Going Public on Innovative Productivity and Exploratory Search
Authors: Wu Geraldine A.
Published: July 2011

This paper investigates whether and how going public affects firm innovation. I propose that initial public offerings (IPOs) fundamentally reshape core organizational structures and processes, and I consider implications for firms' overall innovative productivity and their exploratory search strategies. Using longitudinal data on U.S. medical device firms funded by venture capital and inverse probability of treatment weights to account for self-selection into IPOs and the presence of time-dependent confounders, I find that a firm's overall innovative productivity increases after the firm goes public. Going public also decreases the proportion of innovation search that explores new and recently developed knowledge and increases the proportion of exploratory search building on scientific knowledge. Estimates represent population average treatment effects.
Institutions, Capabilities, and Contracts: Make or Buy in the Electric Utility Industry
Authors: Fabrizio Kira R.
Published: July 2011

This paper integrates transaction cost economics with the resource-based view of the firm and new institutional economics to examine how firms' capabilities and institutional environments influence governance decisions. We demonstrate that the impact of firm capabilities on governance choice varies with the level of transaction costs, which is itself a function of the institutional environment. Based on panel data for 240 investor-owned utility companies in 1990–2007, we find that firms with strong institutional safeguards, prior contracting experience, and inferior firm production capabilities will buy more electricity, and make less, to meet increases in demand. We also find that institutional safeguards substitute for prior contracting experience and increase the influence of production capabilities on governance decisions. These findings suggest that firm heterogeneity is a significant factor in governance decisions and that firms' capabilities and institutional environments merit additional consideration in the study of firm governance.
Hepatic arterial infusion enhances DOTATOC radiopeptide therapy in patients with neuroendocrine liver metastases
Authors: Kratochwil Clemens , López-Benítez Ruben , Mier Walter , Haufe Sabine , Isermann Berend , Kauczor Hans-Ulrich , Choyke Peter L , Haberkorn Uwe , Giesel Frederik L
Published: July 2011

Intravenously administered radiolabeled peptides targeting somatostatin receptors are used for the treatment of unresectable gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Recently, we demonstrated a high first-pass effect during intra-arterial (i.a.) administration of positron emission tomography (PET) labeled 68Ga-DOTA0-d-Phe1-Tyr3-octreotide (DOTATOC). In this pilot study, we investigated the therapeutic effectiveness of arterial administered DOTATOC, labeled with the therapeutic β emitters 90Y and 177Lu. 90Y- and/or 177Lu-DOTATOC were infused into the hepatic artery of 15 patients with liver metastases arising from GEP-NETs. Response was assessed using DOTATOC-PET, multiphase contrast enhanced computed tomography, magnetic resonance imaging, and the serum tumor marker chromogranin A. Pharmacokinetic data of the arterial approach were assessed using 111In-DOTATOC scans. With the treatment regime of this pilot study, complete remission was achieved in one (7%) patient and partial remission was observed in eight (53%) patients, six patients were classified as stable (40%; response evaluation criteria in solid tumors criteria). The concomitant decrease of elevated serum tumor marker confirmed the radiologic response. Median time to progression was not reached within a mean follow-up period of 20 months. Receptor saturation and redistribution effects were identified as limiting factors for i.a. DOTATOC therapy. The high rate of objective radiologic response in NET patients treated with arterial infusion of 90Y-/177Lu-DOTATOC compares favorably with systemic chemotherapy and intravenous radiopeptide therapy. While i.a. DOTATOC therapy is only applicable to patients with tumors of limited anatomic distribution, the results of this pilot study are a promising development in the treatment of GEP-NET and warrants further investigation of this novel approach.
Controversial issues in colorectal screening in Hungary
Authors: Döbrőssy Lajos , Kovács Attila , Budai András , Simon Judit , Horváth Andrea Rita , Cornides Ágnes , Tulassay Zsolt
Published: July 2011

In Hungary, mortality rates from colorectal cancer are dramatically high, therefore the reduction by population screening as a public health measure is considered as one of the priorities of National Public Health Program. In the beginning, a human-specific immunological test was applied in the „model programs”, as a screening tool, to detect the occult blood in the stool; compliance was 32% in average. However, the objectives of the model programs have not been achieved, because – among other reasons – a debate on method to choice and the strategy to follow have divided the professional public opinion. In this study the debated issues are critically discussed, being convinced that – at present – population screening seems to be the most promising way to alleviate the burden of colorectal cancer. Orv. Hetil., 2011, 152, 1223–1232.
Atomic Layer Deposition of Aluminum Nitride Thin films from Trimethyl Aluminum (TMA) and Ammonia
Authors: Liu Xinye , Ramanathan Sasangan , Lee Eddie , Seidel Thomas E.
Published: July 2011

Aluminum nitride (AlN) thin films were deposited from trimethyl aluminum (TMA) and Ammonia (NH3) by thermal atomic layer deposition (thermal ALD) and plasma enhanced atomic layer deposition (PEALD) on 200 mm silicon wafers. For both thermal ALD and PEALD, the deposition rate increased significantly with the deposition temperature. The deposition rate did not fully saturate even with 10 seconds of NH3 pulse time. Plasma significantly increased the deposition rate of AlN films. A large number of incubation cycles were needed to deposit AlN films on Si wafers. 100% step coverage was achieved on trenches with aspect ratio of 35:1 at 100 nm feature size by thermal ALD. X-ray diffraction (XRD) data showed that the AlN films deposited from 370 °C to 470 °C were polycrystalline. Glancing angle X-ray reflection (XRR) results showed that the RMS roughness of the films increased as the film thickness increased.
Processing and On-Wafer Measurements of Ferroelectric Interdigitated Tunable Microwave Capacitors
Authors: Grishin Alexander M. , Kim Jang-Yong , Khartsev Sergey I.
Published: July 2011

Na0.5K0.5NbO3 (NKN) and Pb(Zr0.53Ti0.47)O3 (PZT) films have been grown by rf-magnetron sputtering and pulsed laser deposition techniques, correspondingly, on sapphire (Al2O3-0112, rcut), YAlO3 + 1% Nd (Nd:YAlO3-001), and quartz (Y+36°-cut) single crystal substrates. Interdigital capacitor (IDC) of coplanar waveguide (CPW) structures were defined by a standard lift off technique in a Au(0.5μm)/Cr(10nm) electrode electron beam evaporated on ferroelectric film surface. IDCs consisted of five pairs of fingers separated by 2 and 4 μm gap. On-wafer microwave characterization was performed using a workbench equipped with a coplanar probe station (Cascade Microtech) with G-S-G (Ground-Signal-Ground) Picoprobe, a network analyzer (Agilent Technologies E8364A) operating in 45 MHz to 40 GHz range and programmable power supply for dc DUT (Device Under Test) biasing. Assumed equivalent circuit for the IDC/CPW structure contains planar capacitor under test C, the coplanar line with a complex impedance ς and a parasitic capacitance Cp between the signal and ground lines. The de-embedding technique has been employed to determine all six complex parameters C, ς and Cp from S-parameter measurements performed for three different device structures: device, open and thru. NKN film interdigital capacitors on sapphire show superior performance in this microwave range: the frequency dispersion was as low as 18%, voltage tunability = 1 – C(40V)/C(0) (40 V, 200 kV/cm) about 14%, loss tangent ∼ 0.11, K-factor = tunability/tanδ from 131% @ 10 GHz to 56% @ 40 GHz. The reliability of the de-embedding procedure is clearly proved by analysis of the frequency dependences of the parasitic capacitance and loss tangent as well as impedance of the coplanar line. Within the accuracy of experimental data and de-embedding calculations these values appear to be voltage independent: Cp ∼ 70 fF, tan δp changes from 0.07@10 GHz to 0.15@40 GHz; real and imaginary part of interconnect impedance increases with frequency from 0.16Ω@10 GHz to 0.36Ω@40 GHz and from 1.6Ω@10 GHz to 5.84Ω@40 GHz respectively.
Study of pulsed RF DPN process parameters for 65 nm node MOSFET gate dielectrics
Authors: Rothschild A. , Kraus P. A. , Chua T.C. , Nouri F. , Cubaynes F.N. , Veloso A. , Mertens S. , Date L. , Schreutelkamp R. , Schaekers M.
Published: July 2011

In order to understand how N2plasma conditions impact on the incorporation of nitrogen species into a thin SiO2(1.4 nm), tuning of some pulsed RF (pRF) Decoupled Plasma Nitridation (DPN) process parameters was performed: duty cycle (DC) or on-time per period, frequency (f), process time (t) and some cross-combinations (DC*f, DC*t, DC*f*t). The N2plasma and the SiOxNyfilm were characterized using Langmuir probe analysis (LP) and Delay to Reoxidation (D2R) techniques, respectively. Correlations are established between ion density and electron temperature and the resultant nitrogen concentration and parasitic physical thickness increase. The LP results indicate that while DC impacts the ion density and energy, the frequency has no impact to first order. This is consistent with the physical characteristics of the film. From the combination of DC*f*t, the importance of the off-time portion of the pulse was revealed. With the help of a modified pulsed RF DPN generator, allowing a decrease of the frequency down to 2 kHz, a 5% improvement of the drive current for pMOS transistors was obtained.
Characterization of High-κ Nanolaminates of HfO2 and Al2O3 Used as Gate Dielectrics in pMOSFETs
Authors: Wu Dongping , Lu Jun , Persson Stefan , Hellström Per-Erik , Vainonen-Ahlgren Elizaveta , Tois Eva , Tuominen Marko , Östling Mikael , Zhang Shi-Li
Published: July 2011

In order to combine the merits of both HfO2 and Al2O3 as high-κ gate dielectrics for CMOS technology, high-κ nanolaminate structures in the form of either Al2O3/HfO2/Al2O3 or Al2O3/HfAlOx/Al2O3 were implemented in pMOSFETs and electrically and microstructurally charachterized. ALD TiN film was used as the metal gate electrodes for the pMOSFETs. After full transistor-processing including a rapid thermal processing step at 930 °C, the HfO2 film in the former nanolaminate was found to be crystallized. In contrast, the HfAlOx layer in the latter nanolaminate remained in the amorphous state. Both types of pMOSFETs exhibited a hysteresis as small as ∼20 mV in C-V characteristics in the bias range of +/− 2 V. They also showed a reduced gate leakage current. The pMOSFET with the Al2O3/HfAlOx/Al2O3 nanolaminate was characterized with a subthreshold slope of 77 mV/decade and a channel hole mobility close to the universal hole mobility curve. The pMOSFET with the Al2O3/HfO2/Al2O3, however, exhibited a subthreshold slope of 100 mV/decade and a ∼30% lower hole mobility than the universal curve.
Electrical breakdown in a two-layer dielectric in the MOS structure
Authors: Yang Xiaolong , Xie Qianghua , Tao Meng
Published: July 2011

The formation of interfacial oxide between high-k and Si creates a two-layer dielectric in the MOS structure. In this paper, we present a model to describe electrical breakdown in the two-layer dielectric. Depending on the thickness ratio of the two dielectric layers, electrical breakdown can occur either in one dielectric after the other or simultaneously. In the case of one-by-one breakdown, the current through the two-layer dielectric shows three regimes with applied voltage: tunneling through two layers, tunneling through one layer, and breakdown for both layers. Our model has been compared with experimental data obtained from the HfOx/SiO2 MOS structure, and a good agreement is achieved. This model can be used to estimate either the thickness, breakdown field, or dielectric constant of each of the two dielectric layers. It can also predict the overall breakdown voltage for different combinations of dielectric layers. When combined with C-V measurements, more information about the two-layer dielectric is obtained.
Engineering the nm-thick Interface Layer Formed Between a High-k Film and Silicon
Authors: Lu J. , Tewg J. -Y. , Kuo Y.
Published: July 2011

The interface layer between thin sputter-deposited tantalum oxide (TaOx) high-k film and silicon substrate was engineered with the Hf doping method and the insertion of a thin 5Å TaNx interface. The following results have been obtained: 1) the Hf dopant in the TaOx film was involved in the interface formation process, e.g., forming a new, thinner high-k HfSixOy interface layer rather than the SiOx layer, 2) when the TaNx interface was inserted, the interface layer composition was even more complicated, e.g., including TaOxNy and HfSixOy structures. No hafnium nitride or oxynitride was detected, 3) the interface layer structure was changed, e.g., from single-zone to multi-zone with different compositions, 4) when a low concentration of Hf existed in the TaOx film, the high-k dielectric properties, such as the k value, fixed charge density, dielectric strength, were improved, and 5) when the thin TaNx interface layer was inserted, the above electric properties were further improved. However, the fixed charge density and interface states were increased due to the insertion of the TaNx interface layer. These results were contributed by factors such as the charge-trapping characteristics in the interface layer and the some damage repairing mechanisms. In summary, this research proved that the high-k film's interface layer and bulk properties could be were improved with the doping process as well as the insertion of an ultra-thin TaNx interface film.
Controlling Area-Selective Atomic Layer Deposition of HfO2 Dielectric by Self-assembled Monolayers
Authors: Chen Rong , Kim Hyoungsub , McIntyre Paul C. , Bent Stacey F.
Published: July 2011

A series of self-assembled molecules have been investigated as deactivating agents for the HfO2 atomic layer deposition (ALD). Three important factors of self-assembled monolayers (SAMs) deactivating efficiency towards ALD--chain length, reactivity and steric effect--have been investigated and discussed as well as the initial blocking mechanism of this process. This investigation shows that in order to achieve satisfactory deactivation, it is crucial to choose high reactivity, low steric effect molecules with certain chain length to form condensed, high hydrophobic organic monolayers.
Structural, Dielectric and Pyroelectric properties of Lanthanum modified Lead Titanate Thin Films
Authors: Chopra Sonalee , Sharma Seema , Goel T.C. , Mendiratta R.G.
Published: July 2011

Ferroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.
Effects of Annealing on the Mechanical and Electrical Properties of DC Sputtered Tantalum Pentoxide (Ta2O5) Thin Films
Authors: Purswani J. M. , Pons A. P. , Glass J. T. , Evans R. D. , Cogdell J. D.
Published: July 2011

Tantalum oxide (Ta2O5) films were deposited onto p-type silicon substrates using reactive DC magnetron sputtering, and then annealed for one hour in a dry air ambient at temperatures of 730°C, 780°C, and 830°C. Annealing was shown to reduce stress from the as-deposited sample, and resulted in a compressive stress state for samples annealed at 730°C and a tensile stress state for the other samples. Hardness values were approximately 8 GPa, with the exception of the sample annealed at 780°C that demonstrated a hardness of 13 GPa. Leakage current generally decreased with annealing, especially at the lower temperatures. Electrical breakdown was observed for as-deposited and the 830°C annealed films. Resistivities of the films ranged from 6.5 × 109 to 6.1 × 1012 ω-cm, with the film annealed at 830°C being the most conductive. Annealing also led to an increase in dielectric constant. Dielectric constants varied from 9.3 for the as-deposited to greater than 30 for the 780°C and 830°C annealed sample. Annealing resulted in crystalline films that were close to stoichiometric.
Tunable Workfunction with TaN Metal Gate on HfO2-HfxSiyO Dielectrics
Authors: Olsen Christopher S. , Kraus Philip A. , Ahmed Khaled Z. , Kher Shreyas , Hung Steven , Krishna Nety , Chen Jeff , Date Lucien , Burey Marc , Campbell Jason
Published: July 2011

MOS capacitors were fabricated from MOCVD HfO2 and HfxSiyO gate dielectrics with ALD TaN / PVD Ta metal electrodes. Dielectrics with 1.8 to 2.6 nm capacitance equivalent thickness (CET) were investigated with gate leakage (Jg) of 1×10−7 to 1×10−3 A/cm2 at Vg = Vfb−1V in accumulation. In addition to the C-V and I-V characterization of the MOSCAPs, XPS physical characterization was performed on monitor wafers to determine composition and physical thickness. From the combined results of the electrical and physical characterization, the relative dielectric constants of the Hf-Si-O films and the metal electrode work functions are determined, and simple models for the compositional dependence of the dielectric constant are formulated. Capacitors with the same dielectric composition and thickness exhibited 100 mV Vfb change when the thickness of the ALD TaN electrode layer was changed from 40-80Å. This change is attributed to a change in the work function of the aggregate TaN / Ta metal electrode. Workfunctions were found to be located near middle of the Si band gap, with workfunctions of 4.6 eV to 4.7 eV.
Physical characterization of HfO2deposited on Ge substrates by MOCVD.
Authors: Van Elshocht S. , Brijs B. , Caymax M. , Conard T. , De Gendt S. , Kubicek S. , Meuris M. , Onsia B. , Richard O. , Teerlinck I. , Van Steenbergen J. , Zhao C. , Heyns M.
Published: July 2011

Germanium is because of its intrinsically higher mobility than Si, currently under consideration as an alternative approach to improve transistor performance. Germanium oxide, however, is thermodynamically unstable, preventing formation of the gate dielectric by simple oxidation. At present, high-k dielectrics might be considered as an enabling technology as much progress has been made in the deposition of thin high-quality layers.

In this paper, we study the growth and physical properties of HfO2 deposited on Ge by MOCVD, using TDEAH and O2 as precursors, and compare the results to similar layers deposited on silicon substrates. Our results show that the physical properties of MOCVD-deposited HfO2 layers on Ge are very similar to what we have observed in the past for Si. Unfortunately, some of the negative aspects observed for Si, such as diffusion of substrate material in the high-k layer, a low density for thinner layers, or a rough top surface, are also observed for the case of Ge. However, careful surface pretreatments such as NH3 annealing the Ge substrate prior to deposition, can greatly improve the physical properties. An important observation is the very thin interfacial layer between HfO2 and Ge substrate, allowing a more aggressive scaling for Ge.
Defect Energy Levels in HfO2, ZrO2, La2O3 and SrTiO3
Authors: Xiong K , Peacock P W , Robertson J
Published: July 2011

Defect energy levels of oxygen vacancies in various high K oxides HfO2, ZrO2, La2O3 and SrTiO3 have been calculated using methods which give the correct band gap, such as the screened exchange and weighted density approximation.
Ultrathin Dielectric Films Grown by Solid Phase Reaction of Pr with SiO2
Authors: Müssig Hans-Joachim , Dąbrowski Jarek , Wenger Christian , Łupina Grzegorz , Sorge Roland , Formanek Peter , Zaumseil Peter , Schmeißer Dieter
Published: July 2011

We have fabricated Pr-based high-k gate dielectric films by physical vapor deposition of metallic Pr on SiO2 under ultra-high vacuum (UHV) conditions at room temperature, followed by oxidation and annealing steps. The films have been analyzed by electrical measurements, X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). Some insight into the physical processes involved has been obtained from ab initio calculations. The high-k gate stacks consist of a SiO2-based buffer with an enhanced dielectric constant and a Pr silicate barrier with a high dielectric constant. The role of the buffer is to preserve the high quality of the SiO2/Si(001) interface, and the role of the barrier is to keep the tunneling currents low by increasing its physical thickness. A Pr film deposited on a 1.8 nm SiO2 layer, oxidized at room temperature by air, and annealed in N2 atmosphere with O2 partial pressure of 10−3 mbar results in a stack with the Capacitance Equivalent Thickness of 1.5 nm and leakage of 10−4 A/cm2.
Atomic Vapour Deposition (AVD™) Process for High Performance HfO22 Dielectric Layers
Authors: Cosnier V. , Dabertrand K. , Blonkowski S. , Lhostis S. , Zoll S. , Morand Y. , Descombes S. , Guillaumot B. , Hobbs C. , Rochat N. , Rolland G. , Renault O. , Garros X. , Cassé M. , Mitard J. , Lehnen P. , Miedl S. , Lindner J. , Schumacher M.
Published: July 2011

Hf-family compounds have been widely studied as high k gate dielectric materials, they can be elaborated in a wide range of deposition techniques but ALD and MOCVD are the most advanced. In this contribution, the deposition of pure HfO2 is performed by Atomic Vapour Deposition, which is a sort of pulsed-mode MOCVD. The precursor, diluted into a solvent, is pulsed through specific injectors (TriJet®), micro-droplets are vaporised and distributed to the substrate through a showerhead. ATR-FTIR and Hg-probe measurements have been extensively used to evaluate the materials. The advantage of this specific MOCVD system is that it allows working within a wide range of liquid injection frequencies. Thus, we have been able to show that the frequency of injection has a huge impact on the structural and electrical properties of the material. It has been evidence that working at low frequencies is crucial in order to get good electrical behaviour. Higher temperature deposition shows also a clear benefit. An EOT of 1.15 nm with 6.10−2 A/cm2 at |Vfb| + 1 V, that is to say about 3 orders of magnitude below what is obtained with SiO2 has been obtained on capacitors with TiN gate. This is a very good achievement fore pure HfO2 deposited by MOCVD.

This work has been made in the frame of MEDEA + T207 European project with the help of Air Liquide and Epichem.
Impact of an Antimicrobial Allergy Label in the Medical Record on Clinical Outcomes in Hospitalized Patients
Authors: Charneski Lisa , Deshpande Gaurav , Smith Sheila Weiss
Published: July 2011

Study Objective. To determine the impact of having an antimicrobial allergy label in the medical record on clinical outcomes in hospitalized patients.

Design. Retrospective cohort study.

Setting. Urban academic teaching hospital.

Patients. A total of 11,872 adults admitted to nonsurgical patient care wards who received at least one antimicrobial between August 1, 2007, and July 31, 2008; of these patients, 1324 (11.2%) had an antimicrobial allergy label and 10,548 (88.8%) did not have an allergy label documented in the medical record.

Measurements and Main Results. The following clinical outcomes were compared in patients with allergy labels versus patients without allergy labels: length of stay, admission to the intensive care unit (ICU), number of antimicrobials received during hospitalization, readmission within 4 weeks of hospital discharge, and death during hospitalization. Presence of an allergy label in the medical record was associated with increased length of stay, a higher ICU admission rate, receipt of more than one antimicrobial, and a higher mortality rate during the hospitalization. Logistic regression models were used to assess the association of allergy label with these outcomes while adjusting for covariates (age group, sex, surgery during hospitalization, and season of admission); multiple regression was used to model the association of allergy label with length of stay. On average, length of stay was 1.21 days (unadjusted) and 1.16 days (adjusted for covariates) longer in patients with allergy labels. The likelihood of an ICU admission were 1.4 times (adjusted odds ratio [OR 1.42, 95% confidence interval [CI 1.21–1.67) higher in patients with allergy labels. Presence of an allergy label was also associated with receipt of more than one antibiotic during the hospitalization (crude OR 1.61, 95% CI 1.43–1.81) and a 1.6fold higher risk of dying during the hospitalization (crude OR 1.56, 95% CI 1.20–2.04). Presence of an allergy label was not associated with an increased risk of readmission within 4 weeks of discharge (adjusted OR 0.71, 95% CI 0.63–0.80).

Conclusion. Presence of an allergy label in the medical record was associated with increased length of hospital stay and worse clinical outcomes compared with no allergy label in hospitalized patients treated with antimicrobials.
The Anabolic 500 Survey: Characteristics of Male Users versus Nonusers of Anabolic‐Androgenic Steroids for Strength Training
Authors: Ip Eric J. , Barnett Mitchell J. , Tenerowicz Michael J. , Perry Paul J.
Published: July 2011

Study Objective. To contrast the characteristics of two groups of men who participated in strength‐training exercise—those who reported anabolic‐androgenic steroid (AAS) use versus those who reported no AAS use.

Design. Analysis of data from the Anabolic 500, a cross‐sectional survey.

Participants. Five hundred six male self‐reported AAS users (mean age 29.3 yrs) and 771 male self‐reported nonusers of AAS (mean age 25.2 yrs) who completed an online survey between February 19 and June 30, 2009.

Measurements and Main Results. Respondents were recruited from Internet discussion boards of 38 fitness, bodybuilding, weightlifting, and steroid Web sites. The respondents provided online informed consent and completed the Anabolic 500, a 99‐item Web‐based survey. Data were collected on demographics, use of AAS and other performance‐enhancing agents, alcohol and illicit drug use, substance dependence disorder, other Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnoses, and history of sexual and/or physical abuse. Most (70.4%) of the AAS users were recreational exercisers who reported using an average of 11.1 performance‐enhancing agents in their routine. Compared with nonusers, the AAS users were more likely to meet criteria for substance dependence disorder (23.4% vs 11.2%, p<0.001), report a diagnosis of an anxiety disorder (10.1% vs 6.1%, p=0.010), use cocaine within the past 12 months (11.3% vs 4.7%, p<0.001), and report a history of sexual abuse (6.1% vs 2.7%, p=0.005).

Conclusion. Most of the AAS users in this study were recreational exercisers who practiced polypharmacy. The AAS users were more likely than nonusers to meet criteria for substance dependence disorder, report a diagnosis of an anxiety disorder, report recent cocaine use, and have a history of sexual abuse. The information uncovered in this study may help clinicians and researchers develop appropriate intervention strategies for AAS abuse.
Association of Apolipoprotein E Genotype with Duration of Time to Achieve a Stable Warfarin Dose in African‐American Patients
Authors: Cavallari Larisa H. , Butler Christopher , Langaee Taimour Y. , Wardak Nargis , Patel Shitalben R. , Viana Marlos A. G. , Shapiro Nancy L. , Nutescu Edith A.
Published: July 2011

Study Objective. To test the hypothesis that genotypes for proteins affecting vitamin K availability influence the duration of time required to achieve a stable warfarin dose in African‐American patients.

Design. Retrospective cohort study.

Setting. Pharmacist‐managed antithrombosis clinic.

Patients. Ninety‐two African‐American adults whose warfarin therapy was initiated between September 2, 1999, and July 8, 2009.

Measurements and Main Results. During a routine anticoagulation clinic visit, a sample was collected from each patient for genetic analysis. Genotyping was performed for the following variants: apolipoprotein E ε2, ε3, and ε4; NAD(P)H:quinone oxidoreductase (NQO1)*2; cytochrome P450 (CYP) 4F2 V433M; CYP2C9*2, *3, *5, *8, and *11; and vitamin K epoxide reductase complex 1 (VKORC1) ‐1639G>A. Patients' medical records were then reviewed, and data were collected retrospectively for each anticoagulation clinic visit during the first 6 months of warfarin therapy or until dose stabilization. The median time required to reach a stable warfarin dose, defined as the dose that produced therapeutic anticoagulation for three consecutive clinic visits, was 83 days. Compared with the 46 patients who achieved a stable warfarin dose within 83 days, the 46 patients who required longer durations for dose stabilization had a higher frequency of the apolipoprotein E ε3/ε3 genotype (37% vs 59%, p=0.037). Sixty‐one percent of patients with the ε3/ε3 genotype versus 40% of those with an ε2 or ε4 allele had a delay in achieving a stable dose (p=0.037). Neither the CYP4F2 nor NQO1 genotype was associated with warfarin dose stabilization.

Conclusion. Our data support the hypothesis that the apolipoprotein E genotype is associated with duration of time to reach a stable warfarin dose in African‐American patients. Further insight into the genetic effects on warfarin dose stabilization could reveal novel methods to improve anticoagulation control during the warfarin initiation period.
A Phase II Trial of Bevacizumab plus Everolimus for Patients with Refractory Metastatic Colorectal Cancer
Authors: Altomare Ivy , Bendell Johanna C. , Bullock Karen E. , Uronis Hope E. , Morse Michael A. , Hsu S. David , Zafar S. Yousuf , Blobe Gerard C. , Pang Herbert , Honeycutt Wanda , Sutton Linda , Hurwitz Herbert I.
Published: July 2011

Purpose.

For patients with metastatic colorectal cancer (mCRC), no standard therapy exists after progression on 5-fluorouracil, oxaliplatin, irinotecan, bevacizumab, and cetuximab or panitumumab. Preclinical data demonstrated that combined vascular endothelial growth factor and mammalian target of rapamycin inhibition has greater antiangiogenic and antitumor activity than either monotherapy. A phase I study of bevacizumab plus everolimus demonstrated that the combination is safe; activity was seen in several patients with refractory mCRC.

Methods.

Fifty patients with refractory mCRC were enrolled and received bevacizumab at 10 mg/kg every 2 weeks and everolimus at 10 mg orally daily.

Results.

Of the 50 patients enrolled, the median age was 56 years and the median number of prior regimens was four. Forty-seven patients (96%) had prior bevacizumab exposure and 42 patients (84%) had documented progression on prior bevacizumab-based therapy. Forty-nine patients were evaluable for response; eight patients had minor responses (16%) and an additional 15 patients (30%) had stable disease (SD). No complete or partial responses were seen. The median progression-free survival interval was 2.3 months; however, 26% of patients achieved prolonged SD for ≥6 months, and three patients (6%) were on study for >1 year. The median overall survival duration was 8.1 months. The most common grade 1–2 toxicities were mucositis (68%) and hyperlipidemia (64%). Clinically significant grade ≥3 toxicities included hypertension (14%), fistula/abscess/perforation (8%), mucositis (6%), and hemorrhage (2%).

Conclusions.

Bevacizumab plus everolimus is generally tolerable but may have risks related to mucosal damage and/or wound healing. Bevacizumab plus everolimus appears to have modest activity in refractory mCRC in patients.
Bending moments in D-regions of reinforced concrete beams
Authors: do Carmo Ricardo N. F. , Lopes Sérgio M. R.
Published: July 2011

This paper presents a study of the behaviour of D-regions in reinforced concrete frames. Within the study, 12 two-span beams were tested to failure. The type of discontinuity imposed on the test beams reflects some common layouts that take place in nodes of actual reinforced concrete frames. The beams, 6 m long, were divided into two series (a first set had six beams with no crossing column and a second set had six beams with a crossing column at the inner support). The strength and the deformation capacity in beams with geometric discontinuities were studied as well as the influence of the column presence in the development of the plastic hinges. The main results are presented and discussed: evolution of the bending moment diagrams, moment–curvature relationships, plastic rotation behaviour, stiffness of the connection between the two spans and moment redistribution. As explained in the paper, the presence of a geometric discontinuity at the inner support region leads to a sharp decreasing of the ultimate moment at this region and consequently to a great decreasing of the ultimate load of the beam. Other consequences of having discontinuity in beams are explained. A strut-and-tie model was developed and presented. This model could be useful for the design D-regions.
Wind-induced vibrations of buildings: role of transient events
Authors: Kijewski-Correa Tracy , Bentz Audrey
Published: July 2011

The design of tall buildings, in many cases, is governed by habitability limit states, where accelerations predicted from wind tunnel studies emulating stationary, boundary layer flows associated with synoptic winds are compared to accepted standards for occupant comfort. In both the accelerations predicted for these design limit states and the criteria they are evaluated against, tall building design practice has consciously neglected other types of responses that result from more transient wind events, such as thunderstorms, owing to their short duration. In fact, these types of events and the impulse-like responses they induce in dynamically sensitive structures were not even considered in occupant comfort tests on human subjects until very recently. However, full-scale monitoring programmes on tall buildings, and anecdotal reports from their occupants, have verified that these events do occur regularly and are capable of producing accelerations that exceed those generated by their stationary synoptic counterparts at comparable wind speeds, thus generating perceptible motions on more frequent recurrence intervals. Therefore, it becomes important to investigate the dynamic behaviour of tall buildings under transient wind events and to attempt to gain some understanding of the mechanisms causing these large acceleration responses. The present study attempts to do just that, developing analysis frameworks appropriate for non-stationary records and applying them to full-scale data to enable rare insights into the dynamics of tall buildings under transient wind events, particularly those buildings with marked amplitude dependence and coupling between lateral and torsional modes.