bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of nerve growth factor and keratinocyte growth factor on wound healing of the sinus mucosa
Authors: Tan Lorwai , Hatzirodos Nick , Wormald Peter‐John
Published: August 2008

The healing of the sinuses after sinus surgery is often compromised by the development of adhesions. The aim of this study was to determine whether nerve growth factor (NGF) and keratinocyte growth factor (KGF) aid epithelial and fibroblast wound healing after surgery. Two in vitro models were used to compare their effect on wound closure rates and expression of cell adhesion (E‐cadherin), tight junction formation (zona occludens‐1), cell proliferation (proliferative cell nuclear antigen and Ki67), and ciliogenesis (Foxj1 and β tubulin IVb) genes by real‐time reverse transcription polymerase chain reaction. Epithelial cells from sinonasal tissue were seeded in collagen‐coated Transwells, creating an air–liquid interface, and a submergent model was used for fibroblasts. In epithelial cells, NGF (20–50 ng/mL) significantly decreased wound areas to <40% compared with controls that were still 70% of their original sizes by 24 hours (p<0.05). E‐cadherin and zona occludens‐1 expression were up‐regulated by 20‐ and 2.5‐fold, respectively, relative to controls. KGF (5–100 ng/mL) slowed fibroblast proliferation by reducing (0.8‐fold) and Ki67 (0.25‐fold) expression. NGF (10 ng/mL) slowed Ki67 expression by 0.5‐fold. NGF accelerated in vitro epithelial wound closure while NGF and KGF reduced fibroblast proliferation.
Influence of external forces (pressure and shear force) on superficial layer and subcutis of porcine skin and effects of dressing materials: Are dressing materials beneficial for reducing pressure and shear force in tissues?
Authors: Ohura Takehiko , Takahashi Makoto , Ohura Norihiko
Published: August 2008

The purpose of this study was to measure the impact of external shear force and pressure on a superficial layer of skin and subcutaneous layer with an underlying bony prominence, and also to verify how the influence of these external forces can be reduced after dressings are applied. For this purpose, an experimental model was prepared, consisting of porcine skin and a Predia sensor capable of measuring pressure and shear force simultaneously. External force was applied to the skin model using a 1 kg weight consisting of metal beads. As a result, the control of the shear force value in the subcutaneous layer became approximately 35% smaller than the control in the superficial layer. The shear forces present in the subcutaneous layer were significantly reduced to within 31–45% when compared with the control values, depending on the dressing applied. Regarding the maximum pressures in the subcutaneous layer, the pressure measured following movement was 2.4 times higher in the control than the static pressure and they were also 1.3–1.8 times higher than the static pressure in all instances with the dressing tested. All the dressing materials tested proved to be effective in reducing pressure in the subcutaneous layer compared with the control. Film dressings and hydrocolloid dressings were more effective than hydropolymer and hydrocellular dressings. From the above results, we conclude that efforts made to reduce shear force and pressure may be clinically important.
Permissive environment in postnatal wounds induced by adenoviral‐mediated overexpression of the anti‐inflammatory cytokine interleukin‐10 prevents scar formation
Authors: Gordon Ashley , Kozin Elliott D. , Keswani Sundeep G. , Vaikunth Sachin S. , Katz Anna B. , Zoltick Philip W. , Favata Michele , Radu Antoneta P. , Soslowsky Louis J. , Herlyn Meenhard , Crombleholme Timothy M.
Published: August 2008

Wound healing in the mid‐gestation fetus is scarless with minimal inflammation and a unique extracellular matrix. We have previously documented the relative lack of inflammatory cytokines in this environment. We demonstrate that interleukin (IL)‐10 is highly expressed in mid‐gestation human fetal skin but is absent in postnatal human skin. We hypothesize that overexpression of IL‐10 in postnatal skin may replicate a permissive environment for scarless healing. To study the mechanism underlying this process we performed immunohistochemistry for IL‐10 in human mid‐gestation fetal and postnatal skin. We also determined if adenoviral‐mediated overexpression of IL‐10 could allow for scarless wound healing in a murine incisional wound model. Wounds were analyzed at 1–90 days postwounding for effects on scar formation, inflammatory response, and biomechanical properties. Ad‐IL‐10 reconstitutes a permissive environment for scarless healing as shown by reconstitution of a normal dermal reticular collagen pattern and distribution of dermal elements. Compared with controls, Ad‐IL‐10 treated wounds showed reduced inflammatory response and no difference in biomechanical parameters. Therefore, overexpression of IL‐10 in postnatal wounds results in a permissive environment for scarless wound repair, possibly by replicating a fetal wound environment.
Early healing rates and wound area measurements are reliable predictors of later complete wound closure
Authors: Cardinal Matthew , Eisenbud David E. , Phillips Tania , Harding Keith
Published: August 2008

This study was undertaken to determine if healing rates are reliable early predictors of ultimate complete wound closure in venous leg ulcers and diabetic foot wounds. We conducted a retrospective analysis of 306 venous leg ulcers and 241 diabetic foot ulcers enrolled in two large controlled, prospective, randomized pivotal trials to compare topical wound treatments, to determine whether certain early markers of healing could be correlated with later total wound closure. Two‐sided tests at 95% confidence demonstrated that wound margin advance, initial healing rate, percent wound surface area reduction, and wound healing trajectories (all p<0.001) were powerful predictors of complete wound healing at 12 weeks. Wounds with poor healing progress by these criteria at 4 weeks were highly likely to remain unhealed after 8 additional weeks of treatment. Analysis of the diabetic foot ulcers and venous leg ulcers subgroups separately demonstrated consistent statistical test results with high significance; similarly, the results remained valid independent of the topical treatment used. The early prediction of eventual wound healing or nonhealing using early healing rates may enable more efficient triage of patients to advanced healing technologies. We believe that these surrogate markers are robust predictors of healing regardless of wound etiology and that they merit wider use in clinical trials and routine patient care.
Relationship of Symptoms, Perceived Health, and Stigma With Quality of Life Among Urban HIV‐Infected African American Men
Authors: Buseh Aaron G. , Kelber Sheryl T. , Stevens Patricia E. , Park Chang Gi
Published: August 2008

ABSTRACT
Objectives: To explore the relationship of symptom prevalence and intensity, perceptions of health, and stigma on quality of life (QOL) among HIV‐infected African American men.

Design: Cross‐sectional correlational descriptive study.

Samples: The sample consisted of HIV‐infected African American men (N=55), all urban, age range 23–66 years (M=48.84, SD=7.67), average length of time since HIV diagnosis 10.79 years (SD=6.4).

Measurements: A questionnaire consisting of 5 instruments was used: (a) sociodemographic characteristics, (b) Holzemer Signs and Symptom Checklist for HIV, (c) perceptions of health, (d) Berger HIV Stigma Scale, and (e) Holmes HIV/AIDS‐Targeted Quality of Life Scale.

Results: Prevalent symptoms were fatigue (98%), fear (92.7%), shortness of breath (92.7%), gastrointestinal upset (85.5%), numbness (80.0%), and headache (76.4%). Symptoms with the highest intensity were gastrointestinal upset, body changes, fear, and fatigue. Symptom intensity was significantly associated with the measures of stigma and QOL.

Conclusions: The results underscore the importance of incorporating a holistic view of the relationship of symptoms with QOL for HIV‐infected African American men. Without efforts to ameliorate stigmatizing effects, however, nurses may be falling short in helping individual African American men with HIV infection achieve a better QOL.
Factors Affecting Satisfaction Levels of Japanese Volunteers in Meal Delivery Services for the Elderly
Authors: Yanagisawa Hisayo , Sakakibara Hisataka
Published: August 2008

ABSTRACT
Objectives: The purpose of this study was to investigate the factors affecting satisfaction with volunteer work of participants in a meal delivery service for the elderly.

Design: A cross‐sectional study with a self‐administered survey was carried out.

Sample: Of 364 volunteers assisting with a meal delivery service for the elderly in rural towns A (80), B (159), and C (125), 247 responded (response rate: 68%).

Method: An anonymous self‐administered questionnaire survey was administered seeking information about basic attributes, sense of satisfaction with volunteer work, and working circumstances such as human relationships with fellow volunteers, meal service users or professional staff members, opportunities for meetings or workshop, publicity through public relations magazines, and the like.

Results: In multivariate logistic analysis, the sense of satisfaction of volunteers was closely associated with human relations among volunteers (odds ratio [OR] 5.15, 95% Confidence Interval (CI) 1.84–14.40, p<.01), meal service users (OR 3.84, 95% CI 1.37–10.77, p<.05), and professional staff members supervising the meal delivery service (OR 3.53, 95% CI 1.27–9.84, p<.05). Human relations were also affected by the emphasis on communication, consultation with supervisory staff members, having opportunities for meetings, having friends with whom to confer, and publicity through public relations magazines.

Conclusion: Satisfaction levels of volunteers in meal delivery services for the elderly were most affected by human relations with fellow volunteers, meal service users, and professional staff members. Increasing opportunities for communication may be important to promote good human relationships among volunteers and volunteer activities.
Home or Nursing Home: Does Place of Residence Affect Longevity in Patients With Alzheimer's Disease? The Experience of CERAD Patients
Authors: Peterson Bercedis L. , Fillenbaum Gerda G. , Pieper Carl F. , Heyman Albert
Published: August 2008

ABSTRACT
There is concern that life is curtailed when patients with Alzheimer's disease (AD) are institutionalized. To determine whether placement in a nursing home reduces their remaining years of life, we examined the experience of White patients with AD (n=890) enrolled in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Proportional hazards survival analysis using the landmark approach (with the landmark set to 12 months after CERAD entry and reevaluated at succeeding 6‐month time intervals through 5 years) indicated that longevity at home and in the nursing home was comparable. Thus, in these patients enrolled at tertiary care medical centers, living at home or in a nursing home did not affect time to death. These data suggest that when home care is no longer feasible, families and nurses counseling them should not feel that they are curtailing life by placing an AD patient in a nursing home.
A Senior Center–Based Pilot Trial of the Effect of Lifestyle Intervention on Blood Pressure in Minority Elderly People with Hypertension
Authors: Fernandez Senaida , Scales Kasandra L. , Pineiro Johanna M. , Schoenthaler Antoinette M. , Ogedegbe Gbenga
Published: August 2008

OBJECTIVES: To test the feasibility, acceptability, and effect of a senior center–based behavioral counseling lifestyle intervention on systolic blood pressure (BP).

DESIGN: A pre‐post design pilot trial of behavioral counseling for therapeutic lifestyle changes in minority elderly people with hypertension. Participants completed baseline visit, Visit 1 (approximately 6 weeks postbaseline), and a final study Visit 2 (approximately 14 weeks postbaseline) within 4 months.

SETTING: The study took place in six community‐based senior centers in New York City with 65 seniors (mean age 72.29±6.92; 53.8% female; 84.6% African American).

PARTICIPANTS: Sixty‐five minority elderly people.

INTERVENTION: Six weekly and two monthly “booster” group sessions on lifestyle changes to improve BP (e.g., diet, exercise, adherence to prescribed antihypertensive medications).

MEASUREMENTS: Primary outcome was systolic BP (SBP) measured using an automated BP monitor. Secondary outcomes were diastolic BP (DBP), physical activity, diet, and adherence to prescribed antihypertensive medications.

RESULTS: There was a significant reduction in average SBP of 13.0±21.1 mmHg for the intervention group (t(25)=3.14, P=.004) and a nonsignificant reduction in mean SBP of 10.6±30.0 mmHg for the waitlist control group (t(29)=1.95, P=.06). For the intervention group, adherence improved 26% (t(23)=2.31, P=.03), and vegetable intake improved 23% (t(25)=2.29, P=.03).

CONCLUSION: This senior center–based lifestyle intervention was associated with a significant reduction in SBP and adherence to prescribed antihypertensive medications and diet in the intervention group. Participant retention and group attendance rates suggest that implementing a group‐counseling intervention in senior centers is feasible.
Subsequent Fracture in Nursing Home Residents with a Hip Fracture: A Competing Risks Approach
Authors: Berry Sarah D. , Samelson Elizabeth J. , Ngo Long , Bordes Malynda , Broe Kerry E. , Kiel Douglas P.
Published: August 2008

OBJECTIVES:To determine the incidence and predictors of subsequent fracture in nursing home residents with a hip fracture, accounting for the competing risk of death.

DESIGN:Dynamic cohort study.

SETTING:Hebrew Rehabilitation Center, a 725‐bed, long‐term care facility in Boston, Massachusetts.

PARTICIPANTS:Long‐term care residents with a surgically repaired hip fracture (1999–2006) followed through June 30, 2007, for the occurrence of subsequent fracture at any skeletal site.

MEASUREMENTS:Information on age, sex, anatomic location, type of repair, body mass index (BMI), comorbidities, functional status, cognitive status, and medication use were evaluated as potential risk factors for subsequent fracture.

RESULTS:The study included 184 residents with a baseline hip fracture. Thirty‐nine residents (7 men, 32 women) experienced a subsequent fracture over a median follow‐up of 1.1 years. After the baseline hip fracture, 6% of residents experienced a subsequent fracture within 6 months, 12% within 1 year, and 21% within 5 years. In addition, 23% of residents died within 6 months, 31% within 1 year, and 60% within 5 years. High functional status was associated with a five times greater risk of subsequent fracture (high vs low functional status, hazard ratio=5.10,P<.005). Age, sex, BMI, comorbidities, cognitive status, and medication use were not associated with subsequent fracture.

CONCLUSION:Hip fractures are a sentinel event in nursing home residents, with a high incidence of subsequent fracture and death occurring within 1 year. Identification of prefracture characteristics and postfracture complications associated with mortality should help guide secondary prevention efforts in nursing home residents.
Antimicrobial and mechanical properties of acrylic resins with incorporated silver–zinc zeolite – part I
Authors: Casemiro Luciana Assirati , Martins Carlos Henrique Gomes , Pires‐de‐Souza Fernanda de Carvalho Panzeri , Panzeri Heitor
Published: August 2008

Objective: The purpose of thisin vitrostudy was to evaluate the antimicrobial activity of acrylic resins containing different percentages of silver and zinc zeolite, and to assess whether the addition of zeolite alters the flexural and impact strength of the resins.

Background: The characteristics of acrylic resins support microorganism development that can threaten the health of the dentures user.

Material and methods: A microwave‐polymerised (Onda‐Cryl) and two heat‐polymerised (QC20 and Lucitone 550) acrylic resins were used. The materials were handled according to the manufacturers’ instructions. Fifty rectangular‐shaped specimens (8 × 10 × 4mm) were fabricated from each resin and assigned to 5 groups (n = 10) according to their percentage of Irgaguard B5000 silver–zinc zeolite (0%– control, 2.5%, 5.0%, 7.5% and 10%). Flexural strength and Izod impact strength were evaluated. The antimicrobial activity against two strains ofCandida albicansand two strains ofStreptococcus mutanswas assessed by agar diffusion method. Data were analysed statistically by one‐wayanovaand Tukey’s test at 5% significance level.

Results: The addition of 2.5% of Irgaguard B5000 to the materials resulted in antimicrobial activity against all strains. Flexural strength decreased significantly with the addition of 2.5% (QC20 and Lucitone 550) and 5.0% (Onda‐Cryl) of Irgaguard B5000. The impact strength decreased significantly with the addition of 2.5% (Lucitone 550) and 5.0% (QC20 and Onda‐Cryl) of zeolite.

Conclusion: The addition of silver–zinc zeolite to acrylic resins yields antimicrobial activity, but may affect negatively the mechanical properties, depending on the percentage of zeolite.
Retention of telescopic denture in elderly patients with maximum partially edentulous arch
Authors: Stančić Ivica , Jelenković Aleksandra
Published: August 2008

The telescopic denture is one possible solution for prosthetic rehabilitation for a partially dentate arch with few remaining teeth, which is the reason why it is usually considered in elderly patients. The system of double crowns consists of the male component of attachment or patrix, which is cemented to the abutment tooth, and the female component of attachment or matrix, which is the removable part of the restoration.

Retention force represents resistance to those forces which tend to separate the partial denture and supporting tissue in the occlusal direction. Its optimal value is 5–9 N per each patrix and it should strictly be between these limits as a stronger or weaker force will endanger the functionality of the denture or damage the supporting tissue of the abutment teeth.

Objective:  The goal of this study was to establish the exact value of the individual and total retention force of the completed telescopic system.

Method:  The Bredent dynamometer was used for measuring these values. The study involved measuring the individual force of separation of 50 patrix–matrix components, and total force of 20 partial dentures of various designs retained by double crowns made in the Dental Laboratory of the Clinic for Prosthetic Dentistry, Faculty of Stomatology, Belgrade University. The research was carried out in the period from January 2006 to October 2006.

Results and conclusion:  The results showed different values of separation force – from very low values to those exceeding optimal limits. A reduction in the force of separation is necessary in the case of excessive tightness. If there was looseness between patrix and matrix, the cylindrical components of double crowns need to be lined by a suitable composite material.
Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coliσ32 by λCIII
Authors: Halder Sabyasachi , Banerjee Subhamoy , Parrack Pradeep
Published: August 2008

The CIII protein of bacteriophage lambda exhibits antiproteolytic activity against the ubiquitous metalloprotease HflB (FtsH) of Escherichia coli, thereby stabilizing the λCII protein and promoting lysogenic development of the phage. CIII also protects E. coliσ32, another substrate of HflB. We have recently shown that the protection of CII from HflB by CIII involves direct CIII–HflB binding, without any interaction between CII and CIII [Halder S, Datta AB & Parrack P (2007) J Bacteriol189, 8130–8138]. Such a mode of action for λCIII would be independent of the HflB substrate. In this study, we tested the ability of CIII to protect σ32 from HflB digestion. The inhibition of HflB‐mediated proteolysis of σ32 by CIII is very similar to that of λCII, characterized by an enhanced protection by the core CIII peptide CIIIC (amino acids 14–41 of λCIII) and a lack of interaction between σ32 and CIII.
ADVOCATING FOR COMPREHENSIVE ASSESSMENTS IN DOMESTIC VIOLENCE CASES
Authors: D’Ambrosio Zandra
Published: August 2008

Many jurisdictions handle domestic violence cases on a one‐size‐fits‐all basis, with a presumption in favor of a finding of child neglect and removal when children are exposed to domestic violence. Such a standard fails to recognize that not all domestic violence is the same and not all families are equally affected. The impact of domestic violence depends on several factors such as the different types of domestic violence the frequency and intensity of the violence, the frequency and extent of the child's exposure, and each family member's unique experiences and characteristics. This view takes the position that parents’ capacity to participate in counseling and services promoting the health and safety of their children varies, as does the appropriateness of children being removed from the home as a result of exposure to domestic violence. Therefore, this Note proposes that states develop a standard for both courts and child protective agencies that carefully examines each domestic violence case using an individualized factual analysis and attempt to mitigate the effects of a child's exposure to domestic violence by means other than a presumption for or against removal (temporary or permanent) in every case.
THE REPRODUCTIVE AND PARENTAL RIGHTS OF INCARCERATED MOTHERS
Authors: Vainik Jenni
Published: August 2008

Acknowledging the explosive growth in the number of incarcerated women in the United States, this Note critically examines the current treatment of mothers and expectant mothers in the U.S. prison system. This Note highlights the severe inadequacy of current prison policies and accompanying maltreatment of incarcerated women and their children, especially with regard to the frequent separation of mothers from their children and the poor health care available to expectant mothers. The damage inflicted by current prison policies must be comprehensively redressed through the creation of prison nursery programs, halfway houses, the provision of optimal prenatal care, and the elimination of the draconian practice of shackling pregnant women. Such reforms will not only benefit incarcerated women and their children, but will also deter recidivism and promote the welfare of the community at large.
Estuarine capacity in removal of trace metals from contaminated river water, Southern Caspian Sea
Authors: Saeedi Mohsen , Karbassi Abdulreza
Published: August 2008

In the present investigation, the flocculation of dissolved Cd, Cu, Ni, Pb, Mn and Zn with initial concentrations of 1, 2.5 and 5 mg/L in Tadjan River water during mixing with the Caspian Sea water has been studied in order to determine estuarine capacity to remove dissolved metals in the accidental contamination of the river. The flocculation process was investigated on a series of mixtures with salinities ranging from 0.1 to 11 p.p.t. The flocculation rates were indicative of the nonconservative behaviour of Cd, Cu, Ni, Pb, Mn and Zn during estuarine mixing. The order of the final flocculation rate of dissolved metals at 1, 2.5 and 5 mg/L of initial metal concentrations in the river water is as follows:Cu (99%)>Cd (95%)>Zn (88%)>Mn (85%)>Pb (83%)>Ni (73%), Cu(95.6%)>Pb(92.4%)>Cd (90%)>Zn(88.4%)>Mn (81.6%)>Ni(78.8%) and Cd (100%)>Cu(88%)>Ni (85.2%)>Pb (84%)>Zn (83.2%)>Mn (81.2%), respectively. The results also revealed that removal of dissolved metals is not influenced by pH changes and precipitation processes. The flocculation rates revealed that the overall dissolved metal pollution loads may be reduced to about 70% up to about more than 90% during estuarine mixing of Tadjan River with the Caspian Sea water.
Isolation and characterization of 10 microsatellite loci in Callicarpa subpubescens (Verbenaceae), an endemic species of the Bonin Islands
Authors: MORI K. , KANEKO S. , ISAGI Y. , MURAKAMI N. , KATO H.
Published: August 2008

Ten microsatellite loci were isolated and characterized for Callicarpa subpubescens (Verbenaceae), an endemic tree species of the Bonin Islands. The observed number of alleles at each locus ranged from two to eight with an average of 4.9, and the expected heterozygosity ranged from 0.238 to 0.690 with an average of 0.483. All 10 loci were screened in cross‐amplification tests for two other endemic Callicarpa species that also inhabit the Bonin Islands. All loci were successfully amplified in these species.
Isolation and characterization of 100 polymorphic microsatellite loci for the Siberian jay (Perisoreus infaustus)
Authors: JAARI SONJA , VÄLIMÄKI KAISA , MERILÄ JUHA
Published: August 2008

We describe primers and polymerase chain reaction conditions to amplify 100 microsatellite loci from the Siberian jay (Perisoreus infaustus). The primers were tested on two geographically separated Finnish populations. The developed primer pairs yielded an average of 4.72 alleles per locus (range one to 17) and an average observed heterozygosity of 0.55 (range 0.04 to 1).
Prophylactic administration of antibiotics unnecessary following ultrasound‐guided biopsy and ablation therapy for liver tumors: Open‐labeled randomized prospective study
Authors: Sato Shuichi , Mishiro Tomoko , Miyake Tatsuya , Okamoto Eisuke , Furuta Kohichiro , Azumi Takane , Oshima Naoki , Takahashi Yoshiko , Ishihara Shunnji , Adachi Kyoichi , Amano Yuji , Kinoshita Yoshikazu
Published: August 2008

Aim:  To determine the prophylactic effect of antibiotics administration in the prevention of infection following an ultrasound‐guided percutaneous liver biopsy or treatment of liver tumors, we performed an open‐labeled randomized prospective study of patients who received prophylactic antibiotics after undergoing those procedures.

Methods:  We studied 101 patients, with ultrasound‐guided percutaneous aspiration biopsies of the liver performed in 48 to diagnose diffuse liver diseases or liver tumors, while percutaneous ethanol‐injection therapy was performed in two patients with malignant liver tumors and percutaneous radiofrequency ablation was performed in 51 patients. An oral administration of levofloxacin at 400 mg/day was given to 50 of the enrolled patients from the morning of the treatment day for three days. Preventive antibiotics were not administered to the remaining 51 patients. Body temperature, peripheral blood leukocyte number, c‐reactive protein, alanine aminotransferase, and lactic dehydrogenase were measured daily for three days after treatment.

Results:  Most parameters changed following percutaneous treatments of liver tumors, though no significant differences were seen between the patients treated with antibiotics and those untreated. Most significantly, there was no difference in the frequency of post‐procedure infection between the groups.

Conclusion:  Our results suggest that prophylactic administration of antibiotics following a percutaneous liver biopsy and treatment of liver tumors does not have a significant impact on the post‐procedure results or incidence of infection.
Effect of Friction on the Performance of an Octostrut Vibration Isolation Platform
Authors: He L. , Liu L. K. , Liang L. , Zheng G. T.
Published: August 2008

To improve the dynamic environment of a spacecraft, an octostrut vibration isolation platform is designed to replace the payload attach fitting, which can significantly attenuate the vibration transmitted to payload except that an extra isolation frequency is introduced. However, it is found from the experimental results that when the excitation amplitude is lower than a certain level, the first resonance occurs at a higher frequency (i.e., the isolation frequency). This is caused by the nonlinearity that is a result of the friction existing in every actuator. Therefore, in this paper, the friction force of the single actuator is taken into account and is described by a bilinear hysteresis model. With this friction force model, a new nonlinear model of the octostrut vibration isolation platform is established. Meanwhile, the harmonic balance method is used to solve the nonlinear equations. The theoretical and experimental results indicate that the friction plays an important role in the performance of the platform. It is identified from the study that to ensure the performance of an isolator, in its design, either the maximum friction force or the minimum excitation should be restricted.
Parametric Instability of a Traveling Plate Partially Supported by a Laterally Moving Elastic Foundation
Authors: Kartik V. , Wickert J. A.
Published: August 2008

The parametric excitation of an axially moving plate is examined in an application where a partial foundation moves in the plane of the plate and in a direction orthogonal to the plate’s transport. The stability of the plate’s out-of-plane vibration is of interest in a magnetic tape data storage application where the read/write head is substantially narrower than the tape’s width and is repositioned during track-following maneuvers. In this case, the model’s equation of motion has time-dependent coefficients, and vibration is excited both parametrically and by direct forcing. The parametric instability of out-of-plane vibration is analyzed by using the Floquet theory for finite values of the foundation’s range of motion. For a relatively soft foundation, vibration is excited preferentially at the primary resonance of the plate’s fundamental torsional mode. As the foundation’s stiffness increases, multiple primary and combination resonances occur, and they dominate the plate’s stability; small islands, however, do exist within unstable zones of the frequency-amplitude parameter space for which vibration is marginally stable. The plate’s and foundation’s geometry, the foundation’s stiffness, and the excitation’s amplitude and frequency can be selected in order to reduce undesirable vibration that occurs along the plate’s free edge.
Vibration Control and Trajectory Tracking for General In-Plane Motion of an Euler–Bernoulli Beam Via Two-Time Scale and Boundary Control Methods
Authors: Lotfazar Amir , Eghtesad Mohammad , Najafi Ali
Published: August 2008

In this paper, general in-plane trajectory tracking problem of a flexible beam is studied. To obtain the dynamic equations of motion of the beam, Hamiltonian dynamics is used and then Lagrange’s equations of beam dynamics and corresponding expressions for boundary conditions are derived. Resulting equations show that the coupled beam dynamics including beam vibration and its rigid in-plane motion take place in two different time domains. By using two-time scale (TTS) control theory, a control scheme is elaborated that makes the orientation and position of the mass center of the beam track a desired trajectory while suppressing its vibration. TTS composite controller has two parts: one is a tracking controller designed for the slow (rigid) subsystem, and the other one is a stabilizing controller for the fast (flexible) subsystem. For the fast subsystem, the proposed boundary control (BC) method does not require any information about vibration along the beam except at the end points, nor requires discretizing the partial differential equation of beam vibration to a set of ordinary differential equations. So, the method avoids the need for instruments to measure data from vibration of any point along the beam or designing an observer for estimating this information. Also, the proposed method prevents control spillover due to discretization. Simulation results show that fast BC is able to remove undesirable vibration of the flexible beam and the slow controller provides very good trajectory tracking with acceptable actuating forces/moments.
Adaptive Slicing of Moving Least Squares Surfaces: Toward Direct Manufacturing of Point Set Surfaces
Authors: Yang Pinghai , Qian Xiaoping
Published: August 2008

Rapid advancement of 3D sensing techniques has led to dense and accurate point cloud of an object to be readily available. The growing use of such scanned point sets in product design, analysis, and manufacturing necessitates research on direct processing of point set surfaces. In this paper, we present an approach that enables the direct layered manufacturing of point set surfaces. This new approach is based on adaptive slicing of moving least squares (MLS) surfaces. Salient features of this new approach include the following: (1) It bypasses the laborious surface reconstruction and avoids model conversion induced accuracy loss. (2) The resulting layer thickness and layer contours are adaptive to local curvatures, and thus it leads to better surface quality and more efficient fabrication. (3) The curvatures are computed from a set of closed formula based on the MLS surface. The MLS surface naturally smoothes the point cloud and allows upsampling and downsampling, and thus it is robust even for noisy or sparse point sets. Experimental results on both synthetic and scanned point sets are presented.
Evaluating Supplier Performance Using DEA and Piecewise Triangular Fuzzy AHP
Authors: Yuan Shouhua , Liu Xiao , Tu Yiliu , Xue Deyi
Published: August 2008

Data envelopment analysis (DEA) has been widely applied in evaluating multicriteria decision making problems, which have multi-input and multi-output. However, the traditional DEA method does neither take the decision maker’s subjective preferences to the individual criteria into consideration nor rank the selected options or decision making units (DMUs). On the other hand, Satty’s analytical hierarchy process (AHP) was established to rank options or DMUs under multi-input and multi-output through pairwise comparisons. However, in most cases, the AHP pairwise comparison method is not perfectly consistent, which may give rise to confusions in determining the appropriate priorities of each criterion to be considered. The inconsistency implicates the fuzziness in generating the relative important weight for each criterion. In this paper, a novel method, which employs both DEA and AHP methods, is proposed to evaluate the overall performance of suppliers’ involvement in the production of a manufacturing company. This method has been developed through modifying the DEA method into a weighting constrained DEA method by using a piecewise triangular weighting fuzzy set, which is generated from the inconsistent AHP comparisons. A bias tolerance ratio (BTR) is introduced to represent the varying but restrained weighting values of each criterion. Accordingly, the BTR provides the decision maker a controllable parameter by tightening or loosening the range of the weighting values in evaluating the overall performance of available suppliers, which in hence, overcomes the two weaknesses of the traditional DEA method.
Geometric Modeling of Cutter/Workpiece Engagements in Three-Axis Milling Using Polyhedral Representations
Authors: Aras Eyyup , Yip-Hoi Derek
Published: August 2008

Modeling the milling process requires cutter/workpiece engagement (CWE) geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. This geometry defines the instantaneous intersection boundary between the cutting tool and the in-process workpiece at each location along a tool path. This paper presents components of a robust and efficient geometric modeling methodology for finding CWEs generated during three-axis machining of surfaces using a range of different types of cutting tool geometries. A mapping technique has been developed that transforms a polyhedral model of the removal volume from the Euclidean space to a parametric space defined by the location along the tool path, the engagement angle, and the depth of cut. As a result, intersection operations are reduced to first order plane-plane intersections. This approach reduces the complexity of the cutter/workpiece intersections and also eliminates robustness problems found in standard polyhedral modeling and improves accuracy over the Z-buffer technique. The CWEs extracted from this method are used as input to a force prediction model that determines the cutting forces experienced during the milling operation. The reported method has been implemented and tested using a combination of commercial applications. This paper highlights ongoing collaborative research into developing a virtual machining system.
Tunable double dots and Kondo enhanced Andreev transport in InAs nanowires
Authors: Sand-Jespersen T. , Aagesen M. , Sørensen C. B. , Lindelof P. E. , Nygård J.
Published: August 2008

The effect of Kondo correlations on the subgap structure of a quantum dot contacted by superconducting leads is investigated experimentally in indium-arsenide nanowires. When the zero-bias Kondo effect is suppressed by the superconducting pairing of the electrons a profound enhancement of the first-order Andreev reflection is observed. Devices with local gate control allow individual tuning of multiple quantum dots along the wire, a double dot with tunable interdot coupling is demonstrated.
Other one-dimensional systems and thermal properties
Authors: Dresselhaus M. S. , Dresselhaus G. , Hofmann Mario
Published: August 2008

Since the ICON 2007 conference was heavily focused on nanowires, one session was devoted to providing a broader picture of one-dimensional systems and how thermal properties are enhanced in these low-dimensional systems. This article is directed toward giving an overview of these topics, summarizing some of the most relevant issues, and providing a vision for the future directions of these topics.
Depth-resolved cathodoluminescence spectroscopy study of defects in SrTiO3
Authors: Zhang Jun , Walsh S. , Brooks C. , Schlom D. G. , Brillson L. J.
Published: August 2008

The authors report a depth-resolved cathodoluminescence spectroscopy study of defects and their distributions in SrTiO3 single crystals and epilayers. In SrTiO3 single crystals, the dominant defects are oxygen vacancies that locate mainly near the free surface, while Ti interstitials locate further into the bulk. Vacuum annealing increases the density of oxygen vacancies at SrTiO3 surfaces but reduces the density of Ti interstitials located deeper. In epilayers, the density and distribution of the defects depend on the film thickness and stoichiometry. The results reveal a strong dependence of SrTiO3 native point defects and their depth distributions on epitaxial growth and process conditions.
System-level line-edge roughness limits in extreme ultraviolet lithography
Authors: Naulleau Patrick P. , Niakoula Dimitra , Zhang Guojing
Published: August 2008

As critical dimensions shrink, line-edge roughness (LER) and linewidth roughness become of increasing concern. Traditionally, LER is viewed as a resist-limited effect; however, as critical dimensions shrink and LER requirements become proportionally more stringent, system-level effects begin to play an important role. Recent advanced extreme-ultraviolet resist testing results have demonstrated lower bounds on achievable LER at the level of approximately 2–3nm. Here, the authors use modeling to demonstrate that a significant portion of this low bound may, in fact, be do to system-level effects and, in particular, the mask. Of concern are both LER on the mask as well as roughness of the multilayer reflector. Modeling also shows roughness (flare) in the projection optics not to be of concern.
Characterization of photoconductive CdS thin films prepared on glass substrates for photoconductive-sensor applications
Authors: Hur Sung-Gi , Kim Eui-Tae , Lee Ji-Hong , Kim Geun-Hong , Yoon Soon-Gil
Published: August 2008

Cadmium sulfide (CdS) thin films with n-type semiconductor characteristics were prepared at room temperature on glass substrates by radio-frequency magnetron sputtering for photoconductive-sensor applications. Films deposited at room temperature exhibit polycrystalline phases and show smooth surface morphologies. The deposition rate of the films decreases with increasing working pressure. The dark- and photoresistances in 400-nm-thick CdS films deposited at 6.7×10−1Pa and 80W were approximately 1×105 and 3×104Ω∕sq, respectively. Lowering both the dark- and photoresistances lowers the sensitivity (Rdark∕Rphoto) of the resistance.
A thermocompressive bonding method using a pure sputtered Au layer and its wafer scale package application
Authors: Kim Jongseok , Kwon Sangwook , Hong Youngteak , Song Insang , Ju Byeongkwon
Published: August 2008

The authors have developed a thermocompressive bonding method using a sputtered Au layer and applied it to the coplanar waveguide (CPW) package. The bonding temperature is 350°C, the bonding pressure is 63MPa, and the duration time is limited to 30min. The bonding strength is evaluated using the Scotch tape and tweezers detaching method and the hermeticity is evaluated using helium leak detection work station. The measured hermeticity is 1.0×10−9Pam3∕s. To measure the electrical properties, the CPW line is packaged and the rf characteristics and dc resistance are measured. The insertion loss of the packaged CPW line is −0.074dB at 2GHz and the dc resistance is from 0.019to0.046Ω. This result shows that their Au compressive bonding method is very useful and good for microdevice wafer level packaging applications.
Improvement in GaN and AlGaN/GaN Schottky diode performance by reduction in epitaxial film dislocation density
Authors: Ewing D. J. , Derenge M. A. , Shah P. B. , Lee U. , Zheleva T. S. , Jones K. A.
Published: August 2008

The electrical characteristics of AlGaN/GaN heterostructures and GaN Schottky diodes were correlated with dislocations and other material defects. GaN epitaxial films were grown using conventional metal organic chemical vapor deposition (MOCVD) and pendeo-epitaxy, while AlGaN/GaN heterostructures were grown using conventional MOCVD. Current-voltage (I-V) measurements displayed a wide variation in ideality factor and reverse leakage current density. Schottky diodes fabricated on the pendeo-epitaxial material displayed improved ideality factor (n=1.35) and leakage current density measured at −2 V (J=54.5 A/cm2) compared to conventionally grown GaN (n=1.73,J=117 A/cm2). The electrical properties of the Schottky diodes on the AlGaN/GaN heterostructure varied across the sample, showing no spatial dependence. Ideality factor and Schottky barrier height ranged n=1.6−3.0 and ϕB=0.69−0.87, respectively. Reverse leakage current density at −2 V varied by up to three orders of magnitude. Etch pit density and atomic force microscopy revealed three orders of magnitude reduction in dislocation density for the pendeo-epitaxial GaN compared to conventional GaN, while cathodoluminescence indicated lower defect density for the pendeo-epitaxial GaN. Etch pit density revealed almost an order of magnitude lower dislocation density beneath those diodes with improved characteristics on the AlGaN/GaN heterostructure.
Etching rate, optical transmittance, and charge trapping characteristics of Al-rich Al2O3 thin film fabricated by rf magnetron cosputtering
Authors: Nakata Shunji , Nagai Shingo , Kumeda Minoru , Kawae Takeshi , Morimoto Akiharu , Shimizu Tatsuo
Published: August 2008

Radio-frequency magnetron cosputtering by setting an Al metal plate on an Al2O3 target is an effective method for fabricating Al-rich Al2O3 thin film, which is used as a charge storage layer for nonvolatile Al2O3 memory. The wet etching rate of the fabricated AlO film increases with Al content. The optical transmittance decreases when the Al content in AlO increases. Using rf magnetron cosputtering, the authors fabricated an Al2O3 film with an embedded Al-rich Al2O3 and investigated the charge trapping characteristics after a 30 min annealing at 550 °C. C-V characteristics indicate that the Al-rich Al2O3 structure is very stable after annealing. The charge trap density in Al-rich Al2O3 after annealing is much larger than that in stoichiometric Al2O3.
Effects of film reoxidation on the growth and material properties of ultrathin dielectrics grown by rapid thermal nitridation in ammonia
Authors: D’Emic C. , Newbury J. , Scerbo C. , Copel M. , Gordon M.
Published: August 2008

Ultrathin silicon oxynitrides have been used successfully as gate dielectrics for advanced complementary metal-oxide semiconductor technologies. Here, the authors compare the growth and material properties of oxynitrides grown by rapid thermal nitridation of silicon in ammonia (RT-NH3) followed by reoxidation in NO, O2, or N2O. While the nitrogen concentration of the film is primarily determined by the RT-NH3 condition, reoxidation causes a slight change in nitrogen content and increase in film thickness which varies depending on the initial nitrogen concentration in the film and the oxidizing conditions used. The nitrogen/oxygen concentration ratio was determined to be sensitive to the reoxidizing species, process pressure, and exposure time. Compositional analysis by medium energy ion scattering indicates similarities in microstructure but differences in nitrogen and oxygen profiles among the different films. Results indicate that reoxidation in NO, O2, or N2O can result in different nitrogen concentrations at the bottom interface under the same process conditions. Thus, the choice of reoxidizing species may be an important decision for a gate dielectric process since the amount and placement of nitrogen needs to be optimized to reduce the impact on device peak mobility and threshold voltage, while still be sufficient to improve hot carrier reliability, reduce defect generation rates and gate leakage current, and suppress boron penetration from the gate electrode [D. A. Buchanan, IBM J. Res. Dev. 43, 245 (1999); M. L. Green et al., J. Appl. Phys. 90, 205 (2001); E. Gusev et al., IBM J. Res. Dev. 43, 265 (1999)].
X-ray photoelectron spectroscopy and low-energy electron diffraction analyses on the extremely low work-function surface of W(100) modified by yttrium oxide
Authors: Kawakubo Takashi , Shimoyama Yusuke , Nakane Hideaki , Adachi Hiroshi
Published: August 2008

Electron emission concentrates selectively on the (100) surface at the top of a needle-shaped tungsten tip when a slight amount of Y2O3 powder is put on the side surface of the tip and heat-treated afterward [T. Kawakubo et al., J. Vac. Sci. Technol. B 22, 1258 (2004)]. The work function determined by the Fowler-Nordheim plot shows an extremely low value of 2.0eV. The value is much lower than the 4.6eV of the bare tungsten (100) surface and lower than the 2.7eV of the ZrO∕W(100) thermal field-emission cathode, which is used for electron sources for scanning-electron microscopes and for some mask-patterning equipment for the semiconductor industry. The apparently low value of the work function motivated us to investigate the surface using x-ray photoelectron spectroscopy and low-energy electron diffraction. The experimental results do not agree with the results of the ZrO∕W(100) surface.
Electronic signature of MnAs phases in bare and buried films grown on GaAs(001)
Authors: Moreno M. , Kumar A. , Tallarida M. , Ney A. , Ploog K. H. , Horn K.
Published: August 2008

Photoelectron emission spectroscopy analyses of the arsenic bonding in the near-surface region of an initially arsenic-capped MnAs (11¯00) film grown on GaAs(001) have been carried out for progressive thermal decapping stages. Electronically distinct As-bonding states are identified and assigned to bulk MnAs phases, bulk arsenic, and interfacial environments. The arsenic coating imposes mechanical constraints to the MnAs film, in addition to those imposed by the GaAs substrate, which appear to alter the relative stability of the α and β MnAs phases around room temperature.