bluuebunny/crossref_metadata_2025 huggingface dataset:
An Evaluation of an Intervention to Assist Primary Care Physicians in Screening and Educating Older Patients Who Use Alcohol
Authors: Fink Arlene , Elliott Marc N. , Tsai Mark , Beck John C.
Published: September 2005

Objectives:To evaluate whether providing physicians and older patients with personalized reports of drinking risks and benefits and patient education reduces alcohol‐related risks and problems.

Design:Prospective comparison study.

Setting:Community primary care.

Participants:Twenty‐three physicians and 665 patients aged 65 and older.

Intervention:Combined report, in which six physicians and 212 patients received reports of patients' drinking classifications and patients also received education; patient report, in which 245 patients received reports and education, but their five physicians did not receive reports; and usual care.

Measurements:Assessments at baseline and 12 months later to determine patients' nonhazardous (no known risks), hazardous (risks for problems), or harmful (presence of problems) classifications using the Computerized Alcohol‐Related Problems Survey (CARPS). The CARPS contains a scanned screening measure and scoring algorithms and automatically produces patient and physician reports and patient education.

Results:At baseline, 21% were harmful drinkers, and 26% were hazardous drinkers. The patient report and combined report interventions were each associated with greater odds of lower‐risk drinking at follow‐up than usual care (odds ratio=1.59 and 1.23, respectively,P<.05 for each). The patient report intervention significantly reduced harmful drinking at follow‐up from an expected 21% in usual care to 16% and increased nonhazardous drinking from 52% expected in usual care to 58%. Patients in the combined report intervention experienced a significantly greater average decrease in quantity and frequency.

Conclusion:Older primary care patients can effectively reduce their alcohol consumption and other drinking risks when given personalized information about their drinking and health.
Clinical Performance of a Ventricular Automatic Capture Verification Algorithm
Authors: SPERZEL JOHANNES , KENNERGREN CHARLES , BIFFI MAURO , SMITH MITCHELL , KNOPS MARIE , GILL JASWINDER , BOLAND JEAN ,   European Insignia® I Ultra Investigational Group
Published: September 2005

Background: This study was conducted to evaluate the clinical performance of the ventricular automatic capture feature as implemented in the Insignia I Ultra pacemaker system (Guidant) utilizing a variety of ventricular leads

Currently, the optimal programming of the pacemaker output considers both pacemaker efficiency (prolonging battery longevity) and patient safety (adequate safety margin). The ability of a pacemaker to automatically adjust the ventricular output above the pacing threshold while maintaining the appropriate safety margin has been explored since the early 1970s and is only available today in conjunction with a specific low polarization lead system.

Methods: One hundred and five patients were enrolled from 17 European centers utilizing 31 different types of ventricular leads were followed through their 3‐month follow‐up visit. There were no restrictions on the type of ventricular leads used.

Results: The average mean difference between the commanded autothreshold test (0.652 + 0.335 V) and the manual threshold test (0.651 + 0.335 V) was 0.001 + 0.49 (P < 0.0001). The average mean difference between the ambulatory autothreshold test (0.696 + 0.322 V) and the commanded autothreshold test (0.682 + 0.315 V) was 0.002 + 0.74 (P < 0.0001). Holter recordings confirmed that there were no loss of capture incidences without a backup pulse being delivered. In addition, the mean number of backup pulses delivered in a 24‐hour period was less than 0.1% of the total number of paced beats.

Conclusions: This study provided that the automatic capture feature while using a variety of leads accurately determines the ventricular stimulation threshold and safely delivers a backup pulse when required.
Rapid Decline in Acute Stimulation Thresholds with Steroid‐Eluting Active‐Fixation Pacing Leads
Authors: KISTLER PETER M. , KALMAN JONATHAN M. , FYNN SIMON P. , SINGARAYAR SURESH , ROBERTS‐THOMSON KURT C. , LINDSAY CATHERINE B. , KHONG UYEN , SPARKS PAUL B. , STRATHMORE NEIL , MOND HARRY G.
Published: September 2005

Background and Aim: There is an increasing use of active‐fixation leads for cardiac pacing, yet concerns remain regarding initial high stimulation thresholds. The aim was to perform a detailed analysis of pacing parameters at the time of implantation to determine when lead repositioning should be considered.

Methods: We performed a prospective observational study of consecutive new pacemaker implants. Detailed analysis of pacing parameters was collected at 2‐minute intervals for 10 minutes, and at day 1 and week 8 following implant.

Results: Ninety‐four patients underwent implantation of 79 dual‐chamber and 15 single‐chamber pacemakers using active‐fixation leads in both chambers. An initial threshold of >1 V was demonstrated in 45/94 (48%) ventricular leads (mean threshold 1.5 ± 0.3 V). This declined rapidly to 0.9 ± 0.3 V at 4 minutes (P < 0.01), 0.7 ± 0.3 V at 10 minutes (P < 0.01), and 0.6 ± 0.3 V at day 1 (P < 0.01). At day 1, 43/45 leads were <1 V. There were 79 atrial leads. An initial threshold of >1 V (mean 1.7 ± 0.6 V) was demonstrated in 41/79 (52%) leads falling significantly to 1.1 ± 0.5 V at 4 minutes (P < 0.01), 0.9 ± 0.4 V at 10 minutes (P < 0.01), and 0.6 ± 0.2 V at day 1 (P < 0.01). At 10 minutes, 32 of 41 leads demonstrated a threshold of <1 V with all leads <1 V at day 1. Thresholds were maintained medium term.

Conclusions: Active‐fixation leads are commonly associated with initially high thresholds that fall rapidly. An initial threshold of 2 V should be provisionally accepted and retested at 4 minutes. The majority will have a threshold of <1 V the following day. A failure of a high threshold to decline at 4 minutes requires lead repositioning.
Low‐Temperature High‐Pressure Consolidation of Amorphous Al2O3–15 mol% Y2O3
Authors: Thangamani Nithyanantham , Gandhi Ashutosh S. , Jayaram Vikram , Chokshi Atul H.
Published: September 2005

This study examined pressure consolidation of amorphous Al2O3–15 mol% Y2O3 powders prepared by co‐precipitation and spray pyrolysis. The two amorphous powders had similar true densities and crystallization sequences. Uniaxial hot pressing was carried out at 450°–600°C with a moderate pressure of 750 MPa. The co‐precipitated powder could be hot pressed to a maximum relative density of 98% and remained amorphous. Pressure adversely affected the densification of the spray‐pyrolyzed powder by favoring an early crystallization of γ‐Al2O3 phase at 580°C. Plastic deformation of the amorphous phase is believed to be responsible for the large densification of the amorphous powders.
Influence of Test Methods on Fracture Toughness of a Dental Porcelain and a Soda Lime Glass
Authors: Wang Hang , Isgrò Giuseppe , Pallav Prem , Feilzer Albert J. , Chao Yonglie
Published: September 2005

The aim of this study was to investigate the influence of the test method on fracture toughness of a dental porcelain and a soda lime glass. Three methods were used to determine fracture toughness: the indentation strength (IS) by bending, chevron‐notched beam (CNB), and the single‐edge‐notched beam (SENB). In the IS method, the ratio of elastic modulus to hardness (E/H) in the formula was determined by two methods: individual measurement for E and H (ISM) as well as direct estimation from Knoop's indentation method (ISK). The tested materials were a dentin porcelain, a traditional feldspar‐based leucite‐reinforced glass ceramic (Carrara Vincent), and a soda lime glass. Carrara Vincent showed a higher toughness (P<0.01) than glass with all three test methods. The toughness values manifested significant differences between the methods used (P<0.01). The two‐way analysis of variance suggested that the materials tested and the test methods used had interaction effects, which statistically means that differences in materials and methods influenced the comparability of the toughness result. In this study, a first step was made to compare different toughness test methods by testing the toughness of a traditional feldspar‐based leucite‐reinforced glass ceramic and a soda lime glass that has a homogeneous microstructure. An interaction effect of the method and the material used was shown. As a consequence, none of the methods tested is suitable as a universal fracture toughness test method. Further research is needed to investigate more extensively the influence of material composition on the fracture toughness test methods' comparability.
Processing Effects for Integrated PZT: Residual Stress, Thickness, and Dielectric Properties
Authors: Ong Ryan J. , Payne David A. , Sottos Nancy R.
Published: September 2005

Processing effects on the dielectric properties of sol–gel‐derived PbZrO3–PbTiO3 (PZT) films integrated onto Pt/Ti/SiO2//Si substrates are reported. Sol–gel synthesis and deposition conditions were designed to produce films of varying thickness (95–500 nm) with consistent chemical composition (Pb (Zr0.53Ti0.47)O3), phase content (perovskite), grain size (∼110 nm), crystallographic orientation (nominally (111) fiber textured), and measured residual stress. The Stoney method, using laser reflectance to determine wafer curvature, derived biaxial tensile stress values of 150 and 180 MPa for PZT films after a baseline correction for electrode interactions during thermal processing was employed. The PZT films were of high dielectric quality, with low losses and negligible dispersion. Calculated values of dielectric constant (K̄′) were found to decrease from 960 to 600 with decreasing film thickness. A series‐capacitor model successfully recovered a room‐temperature K1′ for the PZT (1,170) in good agreement with bulk reports but was unable to reproduce the expected dielectric anomaly near 380°C. This discrepancy and the resulting diffuse phase transformation were attributed to the biaxial tensile stress present in the PZT films.
The Judicial Confirmation Process: The Difficulty with Being Smart
Authors: Lott John R.
Published: September 2005

Republicans and Democrats both complain about the difficulty in getting judges confirmed when it is their nominees who are up for confirmation, but there has not been any systematic study of either how much worse this problem has gotten or what its causes might be. Several patterns do emerge for data from the beginning of Jimmy Carter's administration through the end of George W. Bush's first term. It is taking even longer for confirmation, and the more important the position, the longer confirmation takes. Among the findings, it took almost three times longer for circuit court judges to be confirmed under George W. Bush than under his father. The rate of confirmation for circuit court judges has also fallen while the confirmation rate for district court judges has risen. Higher‐quality judges, measured by their output once they are on the court (e.g., number of citations to their opinions or number of published opinions), take much longer to get confirmed. Evaluated at the mean judicial quality, a 1 percent increase in judicial quality increases the length of the confirmation process by between 1 and 3 percent. Many of the traditional ex ante measures of judicial quality such as where the judge went to law school or a nominee's American Bar Association (ABA) ratings add little if anything to predicting how well he or she will do on the bench. A 1 percent increase in polarization in the voting differences between the political parties in the Senate produces between a 3 and 10 percent increase in the length of the confirmation process for circuit court judges. Even after accounting for differences in nominee quality, Republican circuit court nominees also have significantly lower ABA ratings than Democratic nominees and ABA scores do not affect the length of circuit court confirmations.
Data Gold Mining: MIDAS and Journey Time Predictors
Authors: Gibbens Richard , Werft Wiebke
Published: September 2005

The Motorway Incident Detection and Automatic Signalling (MIDAS) system data are summaries of traffic volumes, speeds and vehicle types, derived from loop detectors that sense traffic passing over them. These sensors are being rolled out across the UK's strategic highway network (motorways and major A-roads) and data from portions of one of the busiest motorways, the M25, now go back 10 years. Richard Gibbens and Wiebke Werft describe a journey time predictor based on MIDAS and explain how the data can shed light on topical issues such as road pricing.
A Rich Opportunity: Data Analysis in Personal Financial Services
Authors: Hand David J.
Published: September 2005

Certain sectors are well known for employing large numbers of statisticians, points out David Hand. These include the pharmaceutical sector, medical research and government. Less well known, however, is that the personal financial services sector also requires large numbers of numerate people, and that statisticians, with their understanding of risk and uncertainty and their ability to extract information from large quantities of data, are in particular demand.
In Vino Veritas
Authors: Hin Lin Y.
Published: September 2005

Wine consumption, once predominantly in Europe and the USA, is rapidly evolving into a global trend, with lucrative markets opening up in the Far East, notably Japan, Taiwan, Hong Kong and mainland China. The demand for fine wines, in these regions in particular, sends prices rising through the stratosphere. Lin Y. Hin looks at the professional tasters' ratings and considers issues of score consignment and lifetime estimation.
Life and Death Decisions: A Statistician on a Data Monitoring and Ethics Committee
Authors: Campbell Mike
Published: September 2005

It has recently been suggested that many clinical trials should have a data monitoring and ethics committee, and that on this committee should be a statistician. Such committees are attached to individual trials and are distinct from local ethics committees, which are not required to have a statistician and are not concerned solely with trials. Given the plethora of trials, there will be increasing demand for statisticians to sit on these committees. Although it is both an honour and a privilege, Mike Campbell warns that membership should not be undertaken lightly.
Boxplots
Authors: Reese R. Allan
Published: September 2005

Boxplots, or box-and-whisker plots, offer simple visual summaries of samples of data. R. Allan Reese thinks they should be used more widely.
Teaching Potential Energy Functions and Stability with Slap Bracelets
Authors: Van Hook Stephen J.
Published: September 2005

The slap bracelet, an inexpensive child's toy,1 makes it easy to engage students in hands-on exploration of potential energy curves as well as of stable, unstable, and meta-stable states. Rather than just observing the teacher performing a demonstration, the students can manipulate the equipment themselves and make their own observations, which are then pooled to focus a class discussion on potential energy functions and stability.
Modeling Vehicle Rollover
Authors: Hall Jonathan , Magraw Jerry
Published: September 2005

Inspired by the recent paper1 in The Physics Teacher on the dynamics of vehicle rollovers, we modeled “rollover” in a laboratory experiment. The combination of fundamental physical principles, application to a “real world” problem, and ease of doing the experiment with readily available material and equipment makes the experiment an attractive one for use in a high school or introductory college physics course. A suggested method, sample results, and suggestions for further experimentation follow.
Conductors and Insulators: A QuickTime Movie
Authors: Zou Xueli
Published: September 2005

A solid understanding of the difference in the electric properties of conductors and insulators is key to making sense of the rest of the material in introductory electricity and magnetism. When asked “What is a conductor (or insulator)?” many introductory physics students can easily tell you: “A metal is a conductor,” and/ or they recite the definition. However, when asked “How do you know or how do you convince a friend in your physics class that electric charges can move freely in a (electrical) conductor?” most students have great difficulty answering the question.1 Don't be surprised if they just tell you that is what the textbook or physics professor says. This paper will illustrate a simple demonstration using an aluminum pie pan and foam board that helps students develop a solid understanding of the fundamental difference between a conductor and insulator. Table I shows detailed information on how to prepare the demonstration. Like any other electrostatics experiment, this demonstration requires low humidity in air. As a matter of fact, it is very difficult to perform the experiment successfully when a classroom is full of students.2 To help teachers do this, a QuickTime movie of the demonstration is made and can be downloaded from http://www.csuchico.edu/~xzou.
Toward High-Resolution de Novo Structure Prediction for Small Proteins
Authors: Bradley Philip , Misura Kira M. S. , Baker David
Published: September 2005

The prediction of protein structure from amino acid sequence is a grand challenge of computational molecular biology. By using a combination of improved low- and high-resolution conformational sampling methods, improved atomically detailed potential functions that capture the jigsaw puzzle–like packing of protein cores, and high-performance computing, high-resolution structure prediction (<1.5 angstroms) can be achieved for small protein domains (<85 residues). The primary bottleneck to consistent high-resolution prediction appears to be conformational sampling.
Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment
Authors: Webster P. J. , Holland G. J. , Curry J. A. , Chang H.-R.
Published: September 2005

We examined the number of tropical cyclones and cyclone days as well as tropical cyclone intensity over the past 35 years, in an environment of increasing sea surface temperature. A large increase was seen in the number and proportion of hurricanes reaching categories 4 and 5. The largest increase occurred in the North Pacific, Indian, and Southwest Pacific Oceans, and the smallest percentage increase occurred in the North Atlantic Ocean. These increases have taken place while the number of cyclones and cyclone days has decreased in all basins except the North Atlantic during the past decade.
TolC Is Involved in Enterobactin Efflux across the Outer Membrane of
Escherichia coli
Authors: Bleuel Corinna , Große Cornelia , Taudte Nadine , Scherer Judith , Wesenberg Dirk , Krauß Gerd J. , Nies Dietrich H. , Grass Gregor
Published: September 2005

Escherichia coli
excretes the catecholate siderophore enterobactin in response to iron deprivation. While the mechanisms underlying enterobactin biosynthesis and ferric enterobactin uptake and utilization are widely understood, nearly nothing is known about how enterobactin is exported from the cell. Mutant and high-performance liquid chromatography analyses demonstrated that the outer membrane channel tunnel protein TolC but none of the respective seven resistance nodulation cell division (RND) proteins CusA, AcrB, AcrD, AcrF, MdtF (YhiV), or the twin RND MdtBC (YegNO) was essential for enterobactin export across the outer membrane. Mutant
E. coli
strains with additional deletion of
tolC
or the major facilitator
entS
were growth deficient in iron-depleted medium. Strains with deletion of
tolC
or
entS
, but not with deletion of genes encoding RND transporters, excreted very little enterobactin into the growth medium. Enterobactin excretion in
E. coli
is thus probably a two-step process involving the major facilitator EntS and the outer membrane channel tunnel protein TolC. Quantitative reverse transcription-PCR analysis of gene-specific transcripts showed no significant changes in
tolC
expression upon iron depletion. However, iron starvation led to increased expression of the RND gene
mdtF
and a decrease in
acrD
.
d
-Alanylation of Teichoic Acids Promotes Group A
Streptococcus
Antimicrobial Peptide Resistance, Neutrophil Survival, and Epithelial Cell Invasion
Authors: Kristian Sascha A. , Datta Vivekanand , Weidenmaier Christopher , Kansal Rita , Fedtke Iris , Peschel Andreas , Gallo Richard L. , Nizet Victor
Published: September 2005

Group A streptococcus (GAS) is a leading cause of severe, invasive human infections, including necrotizing fasciitis and toxic shock syndrome. An important element of the mammalian innate defense system against invasive bacterial infections such as GAS is the production of antimicrobial peptides (AMPs) such as cathelicidins. In this study, we identify a specific GAS phenotype that confers resistance to host AMPs. Allelic replacement of the
dltA
gene encoding
d
-alanine-
d
-alanyl carrier protein ligase in an invasive serotype M1 GAS isolate led to loss of teichoic acid
d
-alanylation and an increase in net negative charge on the bacterial surface. Compared to the wild-type (WT) parent strain, the GAS Δ
dltA
mutant exhibited increased susceptibility to AMP and lysozyme killing and to acidic pH. While phagocytic uptake of WT and Δ
dltA
mutants by human neutrophils was equivalent, neutrophil-mediated killing of the Δ
dltA
strain was greatly accelerated. Furthermore, we observed the Δ
dltA
mutant to be diminished in its ability to adhere to and invade cultured human pharyngeal epithelial cells, a likely proximal step in the pathogenesis of invasive infection. Thus, teichoic acid
d
-alanylation may contribute in multiple ways to the propensity of invasive GAS to bypass mucosal defenses and produce systemic infection.
Natural Transposon Mutagenesis of Clinical Isolates of
Mycobacterium tuberculosis
: How Many Genes Does a Pathogen Need?
Authors: Yesilkaya Hasan , Dale Jeremy W. , Strachan Norval J. C. , Forbes Ken J.
Published: September 2005

Transposable elements can affect an organism's fitness through the insertional inactivation of genes and can therefore be used to identify genes that are nonessential for growth in vitro or in animal models. However, these models may not adequately represent the genetic requirements during chains of human infection. We have therefore conducted a genome-wide survey of transposon mutations in
Mycobacterium tuberculosis
isolates from cases of human infection, identifying the precise, base-specific insertion sites of the naturally occurring transposable element IS
6110
. Of 294 distinct insertions mapped to the strain H37Rv genome, 180 were intragenic, affecting 100 open reading frames. The number of genes carrying IS
6110
in clinical isolates, and hence apparently not essential for infection and transmission, is very much lower than the estimates of nonessential genes derived from in vitro studies. This suggests that most genes in
M. tuberculosis
play a significant role in human infection chains. IS
6110
insertions were underrepresented in genes associated with virulence, information pathways, lipid metabolism, and membrane proteins but overrepresented in multicopy genes of the PPE family, genes of unknown function, and intergenic sequences. Population genomic analysis of isolates recovered from an organism's natural habitat is an important tool for determining the significance of genes or classes of genes in the natural biology of an organism.
Control of the Expression and Compartmentalization of σ
G
Activity during Sporulation of
Bacillus subtilis
by Regulators of σ
F
and σ
E
Authors: Chary Vasant K. , Meloni Mauro , Hilbert David W. , Piggot Patrick J.
Published: September 2005

During formation of spores by
Bacillus subtilis
the RNA polymerase factor σ
G
ordinarily becomes active during spore formation exclusively in the prespore upon completion of engulfment of the prespore by the mother cell. Formation and activation of σ
G
ordinarily requires prior activity of σ
F
in the prespore and σ
E
in the mother cell. Here we report that in
spoIIA
mutants lacking both σ
F
and the anti-sigma factor SpoIIAB and in which σ
E
is not active, σ
G
nevertheless becomes active. Further, its activity is largely confined to the mother cell. Thus, there is a switch in the location of σ
G
activity from prespore to mother cell. Factors contributing to the mother cell location are inferred to be read-through of
spoIIIG
, the structural gene for σ
G
, from the upstream
spoIIG
locus and the absence of SpoIIAB, which can act in the mother cell as an anti-sigma factor to σ
G
. When the
spoIIIG
locus was moved away from
spoIIG
to the distal
amyE
locus, σ
G
became active earlier in sporulation in
spoIIA
deletion mutants, and the sporulation septum was not formed, suggesting that premature σ
G
activation can block septum formation. We report a previously unrecognized control in which SpoIIGA can prevent the appearance of σ
G
activity, and pro-σ
E
(but not σ
E
) can counteract this effect of SpoIIGA. We find that in strains lacking σ
F
and SpoIIAB and engineered to produce active σ
E
in the mother cell without the need for SpoIIGA, σ
G
also becomes active in the mother cell.
GAUGE THEORIES WITH LORENTZ-SYMMETRY VIOLATION BY SYMPLECTIC PROJECTOR METHOD
Authors: BELICH H. , DE ANDRADE M. A. , SANTOS M. A.
Published: September 2005

The violation of Lorentz symmetry is studied from the point of view of a canonical formulation. We make the usual analysis on the constraints structure of the Carroll–Field–Jackiw model. In this context we derive the equations of motion for the physical variables and check out the dispersion relations obtained from them. Therefore, by the analysis using Symplectic Projector Method (SPM), we can check the results about this type of Lorentz breaking with those in the recent literature: in this sense we can confirm that the configuration of vμspace-like is stable, and the vμtime-like carry tachionic modes.
QUENCHED MEAN LIMIT THEOREMS FOR THE SUPER-BROWNIAN MOTION WITH SUPER-BROWNIAN IMMIGRATION
Authors: HONG WENMING
Published: September 2005

The limiting behavior of the expectation of the super-Brownian motion with super-Brownian immigration under the quenched probability is considered: A central limit theorem is proved for d≥3, an ergodic property is considered for d =2 and a local large deviation is obtained for d = 3.
IRREDUCIBILITY OF THE TRANSITION SEMIGROUP ASSOCIATED WITH THE STOCHASTIC OBSTACLE PROBLEM
Authors: BARBU VIOREL , DA PRATO GIUSEPPE
Published: September 2005

The transition semigroup corresponding to stochastic obstacle problem is irreducible.
CUMULANTS IN NONCOMMUTATIVE PROBABILITY THEORY III: CREATION AND ANNIHILATION OPERATORS ON FOCK SPACES
Authors: LEHNER FRANZ
Published: September 2005

Exchangeability systems arising from Fock space constructions are considered and the corresponding cumulants are computed for generalized Toeplitz operators and similar noncommutative random variables. In particular, simplified calculations are given for the two known examples of q-cumulants.

In the second half of the paper we consider in detail the Fock states associated to characters of the infinite symmetric group recently constructed by Bożejko and Guta. We express moments of multidimensional Dyck words in terms of the so-called cycle indicator polynomials of certain digraphs.
SECOND QUANTIZATION AND THE Lp-SPECTRUM OF NONSYMMETRIC ORNSTEIN–UHLENBECK OPERATORS
Authors: VAN NEERVEN J. M. A. M
Published: September 2005

The spectra of the second quantization and the symmetric second quantization of a strict Hilbert space contraction are computed explicitly and shown to coincide. As an application, we compute the spectrum of the nonsymmetric Ornstein–Uhlenbeck operator L associated with the infinite-dimensional Langevin equation [Formula: see text] where A is the generator of a strongly continuous semigroup on a Banach space E and W is a cylindrical Wiener process in E. Assuming the existence of an invariant measure μ for L, under suitable assumptions on A we show that the spectrum of L in the space Lp (E, μ) (1< p< ∞) is given by [Formula: see text] where Aμ is the generator of a Hilbert space contraction semigroup canonically associated with A and μ. We prove that the assumptions on A are always satisfied in the strong Feller case and in the finite-dimensional case. In the latter case we recover the recent Metafune–Pallara–Priola formula for σ(L).
Effect of Rapid Thermal Annealing on Al Doped n-ZnO Films Grown by RF-Magnetron Sputtering
Authors: Kim Kyoung-Kook , Tampo Hitoshi , Song June-O , Seong Tae-Yeon , Park Seong-Ju , Lee Ji-Myon , Kim Sang-Woo , Fujita Shizuo , Niki Shigeru
Published: September 2005

High-quality Al-doped n-type ZnO (n-ZnO:Al) epilayers have been grown by an rf-magnetron sputtering technique combined with a rapid thermal annealing (RTA) process. The electrical and optical properties of as-deposited samples are considerably improved upon annealing at 900°C for 3 min in nitrogen ambient. The improvement is attributed to the deoxidation of Al-oxides, i.e., the activation of Al dopants. The samples annealed at 900°C produce a mobility of 65.5 cm2/V·s and a carrier concentration of 1.03×1020 cm-3. It is also shown that the sample surface becomes significantly smoother after annealing. The results show that the RTA process effectively improves the electrical and optical properties of the Al-doped ZnO films.
Metamorphic Resonant Tunneling Diodes and Its Application to Chaos Generator ICs
Authors: Maezawa Koichi , Iwase Takashi , Ohno Yutaka , Kishimoto Shigeru , Mizutani Takashi , Sano Kimikazu , Takakusaki Misao , Nakata Hirofumi
Published: September 2005

In this paper we discuss the properties of InGaAs/AlAs metamorphic resonant tunneling diodes (RTDs) on GaAs substrates. The current–voltage, surface roughness, and low-frequency noise characteristics were investigated to clarify the effect of step-grading buffer layers. No degradation of the current–voltage characteristics were observed despite the large surface roughness due to a lattice mismatch. Moreover, low-frequency noise measurements showed only 1/ f noise without special peak structures, and the amplitudes of which were comparable to those of the lattice-matched ones. Next, we fabricated resonant tunneling frequency divider ICs, which is based on the bifurcation phenomenon in a chaos system, on metamorphic substrates. A maximum operation frequency of 88 GHz and good phase noise properties were obtained, which are similar to those of the lattice-matched ones. These results demonstrate the effectiveness of the step-grading buffer layers even for the RTDs that consist of very thin layers and are sensitive to crystal qualities.
Effect of Carrier Distribution on Carrier Cooling in GaAs/AlGaAs Quantum Wells
Authors: Sun Kien Wen , Huang Chu Long , Chen Jyong Wun
Published: September 2005

A quantitative study of the effect of carrier–carrier scattering on carrier distribution in two-dimensional systems is carried out by means of calculations using the dynamically screened Boltzmann equation. Photoexcited carrier relaxation processes in both n-type-doped and undoped quantum wells (QWs) are also studied by time-resolved photoluminescence measurements using an up-conversion technique with a high time resolution of approximately 120 fs. By measuring the time evolution of the photoluminescence (PL) intensity, the scattering rate of electrons into the conduction band minimum is obtained directly. Our simulations and experimental results demonstrate that the presence of the cool distribution does affect the carrier–carrier scattering rates significantly.
pH and Procaine Sensing Characteristics of Extended-Gate Field-Effect Transistor Based on Indium Tin Oxide Glass
Authors: Chou Jung-Chuan , Chiang Jung-Lung , Wu Chin-Lung
Published: September 2005

The pH sensing properties of an extended-gate field-effect transistor (EGFET) based on indium tin oxide (ITO) glass are investigated in this study. The separating structures in the EGFET are examined using a current–voltage measurement system to measure I–V curves. A readout circuit is applied to measure the pH sensing EGFET output voltage, and nonideal factors (drift and hysteresis effects) are monitored in different buffer solutions (pH=1–11). It was found that separating structures for ITO glass sensors have a high pH sensitivity (∼55 mV/pH), a low drift rate and a small hysteresis width in the concentration range between pH=1 and 11 in buffer solutions. The EGFET was used in fabricating a drug-sensitive field-effect transistor (DrugFET) sensor for procaine hydrochloride. The DrugFET was prepared using a combination of the EGFET and a drug-sensitive membrane that measured the procaine concentration in the 1×10-2–1×10-6 mol/L range. The separating structure was used with a procaine DrugFET with a good response (∼200 s) at room temperature.
Highly Reliable 250 W GaN High Electron Mobility Transistor Power Amplifier
Authors: Kikkawa Toshihide
Published: September 2005

A state-of-the-art highly reliable 250 W AlGaN/GaN high electron mobility transistor (HEMT) push-pull transmitter amplifier operated at a drain bias voltage of 50 V is described. The amplifier, combined with a digital predistortion (DPD) system, also achieved an adjacent channel leakage power ratio (ACLR) of less than -50 dBc for 4-carrier wideband code division multiple access (W-CDMA) signals with a drain supply voltage of 50 V. I also demonstrate its stable operation under RF stress testing for 1000 h at a drain bias voltage of 60 V. Stable gate-leakage current for high-temperature operation was verified. Device fabrications on 4 inch sapphire and 3 inch semi-insulating (S.I.) SiC substrates were also addressed. These performances clarify that an AlGaN/GaN HEMTs amplifier is suitable for 3G W-CDMA systems.
Liquid Crystal Negative Lens
Authors: Wang Bin , Ye Mao , Sato Susumu
Published: September 2005

A liquid crystal (LC) negative lens is realized using a two-voltage-driving system. The focal length of the lens is tuned electrically. The properties of the lens are calculated and measured. The LC lens has a very wide focus range, and it preserves its optical quality over the entire range.
Compositional Dependence of Fluorescence Spectra of Cr3+/Cr4+-Doped Calcium Alumino-Silicate Glasses for Broadband Telecommunication
Authors: Yamazaki Hiroshi , Tanabe Setsuhisa
Published: September 2005

The compositional dependence of the optical properties of Cr-doped glasses in a calcium alumino-silicate ternary system were investigated. By 792 nm excitation, two broad emission bands centered at 1000 and 1350 nm, which were attributed to Cr3+ and Cr4+ ions, respectively, were observed. The intensity ratio of these bands changed continuously as the host composition was varied; a positive correlation between the relative intensity of the Cr4+ band and the optical basicity Λ of the host glass was observed. In glasses with Λ=0.68–0.70, the two bands became comparable in their intensities and formed an extremely broad emission band with a bandwidth of more than 500 nm as their superposition.
Phase Formation and Electrical Conductivity of Ba-Doped LaScO3
Authors: Lee Kyu Hyoung , Kim Hye Lim , Kim Shin , Lee Hong Lim
Published: September 2005

Phase formation and conduction behavior in BaO-doped LaScO3 with the perovskite structure have been investigated. The structures of La1-x
Ba
x
ScO3-δ were analyzed to be cubic for La0.6Ba0.4ScO3-δ and La0.5Ba0.5ScO3-δ, a mixture of cubic and orthorhombic for La0.9Ba0.1ScO3-δ, La0.8Ba0.2ScO3-δ and La0.7Ba0.3ScO3-δ, and orthorhombic for La0.95Ba0.05ScO3-δ. La1-x
Ba
x
ScO3-δ showed a pure oxide-ion conduction below intermediate oxygen partial pressures under dry atmosphere. At high oxygen partial pressures, it exhibited mixed oxide-ion and p-type electronic conduction. In the presence of water vapor, proton conduction was observed due to the formation of protonic defects and the bulk conductivity by protons was highest in the composition of La0.5Ba0.5ScO2.75. The apparent activation energy for proton conduction was almost the same in each compound, 0.66–0.68 eV, despite the differences in crystal structure and A-site dopant concentration.
Reduction of Dielectric Losses in Pb(Fe1/2Nb1/2)O3-Based Ferroelectric Ceramics
Authors: Fang Bijun , Shan Yuejin , Tezuka Keitaro , Imoto Hideo
Published: September 2005

Pseudoternary Pb(Fe1/2Nb1/2)O3–PbZrO3–PbTiO3 (PFN–PZ–PT) ferroelectric ceramics with a pure perovskite phase were fabricated by a conventional solid-state reaction method via a B-site oxide mixing route in the whole composition range. The ceramics obtained exhibit marked frequency-dependent dielectric behavior and a large dielectric loss when the concentration of Pb(Fe1/2Nb1/2)O3 exceeds 40 mol %. The large dielectric loss is thought to correlate with the thermally activated hole conduction induced by the partial reduction of Fe3+ to Fe2+ ions during sintering, which can be greatly decreased by adding a small amount of MnO2 or by cycling under an alternating electric field. The values of the dielectric constant and the frequency-dependent dielectric behavior at temperatures around and below the temperatures of the dielectric maximum (T
m) are reduced accordingly. The decrease in dielectric loss is believed to be related to the ionization of the manganese-substituted donor defects. The effect of manganese doping on the depression of mechanical vibration loss also contributes little to the decrease in total dielectric loss through pinning down the rotation of space-charge polarization induced by the combining of complex manganese-substituted defects (Mn2+) with oxygen vacancies and standing near the grain boundaries.
Surface Tension and Viscosity Measurements of Liquid and Undercooled Alumina by Containerless Techniques
Authors: Paradis Paul-François , Ishikawa Takehiko
Published: September 2005

Electrostatic levitation and multi-beam radiative heating overcame contamination and sample position instability problems associated with handling of liquid alumina. This allowed the measurements of the surface tension and viscosity in the superheated and undercooled states using the oscillation drop method. Over the 2190–2500 K interval, the surface tension of alumina was measured as σ(T)=0.64–8.2×10-5 (T-T
m) (N/m), where T
m, the melting temperature, is 2327 K. Similarly, on the same temperature range, the viscosity was determined as η(T)=3.2exp
[43.2×103/(R
T)] (mPa·s). Both sets of data agree well with the literature values.
Surface Segregation of CaF2 in Thin Si(111)/CaF2/Si Multilayers Studied by Total Electron Yield Spectroscopy and In situ Ellipsometry
Authors: Ejima Takeo , Ohuchi Katsumi , Watanabe Makoto
Published: September 2005

Total electron yield (TEY) measurements of a Si(111)/CaF2 single-layer, Si(111)/CaF2/Si double-layers, and Si(111)/CaF2/Si/CaF2 triple-layers were performed at around the Si-L edge from 0° to 80° of angles of incidence. From the resemblance of the spectrum of the Si(111)/CaF2/Si double-layers to those of the Si(111)/CaF2 single- and the Si(111)/CaF2/Si/CaF2 triple-layers and from simulations, it is suggested that the Si layer grows on the bottom CaF2 layer and is covered with a segregated top CaF2 layer in the present multilayers. In situ ellipsometry measurements using a He–Ne laser were also performed during epitaxial Si growth on the Si(111)/CaF2 epitaxial film. The measured track is different from the expected curve of epitaxial Si growth, which suggests that the grown Si layer was a mixture layer of Si platelets (islands) surrounded by CaF2. Furthermore, the track showed that the curvature changed during the Si growth, which suggests that the CaF2 segregation has several steps during the Si growth. From the TEY and ellipsometry results, the diameter of the platelets is estimated as 20.0–100.0 nm, the diffraction effect of the light used being taken into account.
Photochemical Oxidation of Chloromethylphenylsiloxane Self-assembled Monolayer Amplified with Atmospheric Oxygen and Its Application to Micropatterning
Authors: Sugimura Hiroyuki , Hong Lan , Lee Kyung-Hwang
Published: September 2005

An excimer lamp irradiating vacuum ultraviolet (VUV) light 172 nm in wavelength has been applied to the photochemical conversion and micropatterning of a p-chloromethylphenylsilyl self-assembled monolayer (CMPhS-SAM) in the presence of atmospheric oxygen. The terminal functional groups of the CMPhS-SAM, the –CH2Cl, were photochemically converted to polar functional groups, mostly –COOH. This chemical conversion was accelerated with atomic oxygen species photochemically generated through VUV excitation of atmospheric oxygen molecules. By irradiating a CMPhS-SAM sample with VUV thorough a photomask, a microchemical pattern consisting of hydrophobic and hydrophilic regions was formed on the SAM surface. Furthermore, by selectively depositing n-octadecyltrimethoxysilane (ODS) molecules on the hydrophilic region, a binary microstructure consisting of CMPhS and ODS was successfully fabricated with an optimum spatial resolution of 1 µm.
Measurement of Electron Transport Properties of Single Molecules
Authors: Li Xiulan , Xu Bingqian , Xiao Xiaoyin , Hihath Joshua , Tao Nongjian
Published: September 2005

The conductance of a single molecule covalently connected to two gold electrodes can be determined by the statistical analysis of many repeatedly created gold-molecule-gold junctions. Conductance histograms reveal well-defined peaks at integer multiples of a fundamental conductance, which is used to identify the average conductance of a single molecule. The large width of the peaks indicates considerable variations in conductance of individual molecular junctions due to difference in the microscopic details of molecule-electrode contacts. Using the method, electron transport properties of a variety of molecules, from N-alkanedithiol molecules to DNA duplexes, have been studied.
Analysis of Time-Resolved Tunnel Current Signal in Sub-Picosecond Range Observed by Shaken-Pulse-Pair-Excited Scanning Tunneling Miscroscopy
Authors: Takeuchi Osamu , Aoyama Masahiro , Shigekawa Hidemi
Published: September 2005

The data analysis procedure for the time-resolved tunnel current signal obtained by the shaken-pulse-pair method was studied. The fitting function composed of a step function and two double exponential functions that decay from delay time zero towards negative and positive infinities, respectively, reproduced the experimental data. In the analysis, the effects of the interference of the two pulses in a pulse pair, the finite width of impinging pulses, the amplitude of the delay time modulation and the lock-in time constant were considered, for obtaining accurate decay parameters.
Imaging and Manipulation of Initial Oxidation Product on Si(111)-(7×7)
Authors: Okuyama Hiroshi , Yamada Takashi , Aruga Tetsuya
Published: September 2005

The initial reaction of an O2 molecule with Si(111)-(7×7) was studied using a scanning tunneling microscope at 10 K. The reacted site shows a characteristic dark feature which is ascribed to a metastable product with one oxygen atom bonded on top of a Si adatom and another inserted into a back bond. The dark site appears asymmetric with respect to the surface mirror plane, possibly reflecting the location of the inserted oxygen atom. No evidence for molecular chemisorption was obtained even at 10 K. The atomic-scale manipulation of the initial oxidation product was demonstrated.
Simple Model of Electronic Density of States of Graphite and Its Application to the Investigation of Superlattices
Authors: Pong Wing-Tat , Durkan Colm
Published: September 2005

A model of graphite which is easy to comprehend and simple to implement for the simulation of scanning tunneling microscopy (STM) images is described. This model simulates the atomic density of graphite layers, which in turn correlates with the local density of states. The mechanism and construction of such a model is explained with all the necessary details which have not been explicitly reported before. This model is applied to the investigation of rippling fringes which have been experimentally observed on a superlattice, and it is found that the rippling fringes are not related to the superlattice itself. A superlattice with abnormal topmost layers interaction is simulated, and the result affirms the validity of the moiré rotation pattern assumption. The “odd-even” transition along the atomic rows of a superlattice is simulated, and the simulation result shows that when there is more than one rotated layer at the top, the “odd-even” transition will not be manifest.
Carbon Multiprobes with Nanosprings Integrated on Si Cantilever Using Focused-Ion-Beam Technology
Authors: Nagase Masao , Nakamatsu Kenichiro , Matsui Shinji , Namatsu Hideo
Published: September 2005

A new multiprobe system for scanning probe microscopy for electrical property measurements has been developed. Four carbon probes with nanosprings have been grown using focused-ion-beam chemical vapor deposition (FIB-CVD) on a Si cantilever with Al electrodes. The diameter of the carbon probe is 110 nm, and the diameter of the nanospring is 380 nm. The total height of the probe with the nanospring is approximately 10 µm. The stiffness of the probe is sufficiently high for imaging in the contact mode. The nanosprings compensate for the height differences between the four probes. It is confirmed that electrical contacts between a conductive sample and all four probes are established. This is the first report on a FIB-CVD probe with a nanospring actually operating as a nano-electromechanical system.
Adsorption of Fluorescein Isothiocyanate Isomer-I (FITC-I) Dye on TiO2(110) from an Acetone Solution
Authors: Pang Chi Lun , Ishibashi Taka-aki , Onishi Hiroshi
Published: September 2005

We have adsorbed fluorescein isothiocyanate isomer-I (FITC-I) dye (C21H11NO5S) onto the rutile TiO2(110) surface via a substitutional reaction between the dye and a pre-adsorbed, (2×1) ordered trimethyl acetate (TMA) layer. The TMA was prepared by evaporation of trimethyl acetic acid in an ultra-high vacuum (UHV) chamber. The TiO2(110)-(2×1)-TMA crystal was then removed from the vacuum chamber and immersed in a 10 mM FITC-I/acetone solution. The resulting TiO2(110)-FITC-I sample was analysed using UHV scanning tunneling microscopy (STM) and infrared-visible sum-frequency (SF) spectroscopy. STM showed the presence of large, bright spots attributed to adsorbed FITC-I dye molecules and SF spectroscopy showed vibrational bands assignable to FITC-I molecules. Together, this indicates that the dye molecule can be adsorbed intact onto the TiO2(110) surface via an exchange-reaction in solution.
Spatiotemporal Variation in Cellular Stiffness Corresponding to Development of Morphological Polarity
Authors: Toko Satoshi , Mizutani Takeomi , Haga Hisashi , Kawabata Kazushige
Published: September 2005

The spatiotemporal variation in the local stiffness of fibroblasts was visualized successfully using wide-range scanning probe microscopy (SPM) in the force mapping mode when the cells attach and spread on a substratum, to clarify the cellular mechanical effects on the development of morphological polarity. We found that the stiffness distribution in inhomogeneous in a circular cell. When the cell shape is polarized, several stiff bands appear clearly along the direction of the morphological polarity. The SPM measurements give new information on the cellular mechanical effect on the development of morphological polarity.