930 research outputs found

    Development and Initial Psychometric Evaluation of the Computer-Based Prostate Cancer Screening Decision Aid Acceptance Scale for African-American Men

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    BACKGROUND: To reliably evaluate the acceptance and use of computer-based prostate cancer decision aids (CBDAs) for African-American men, culturally relevant measures are needed. This study describes the development and initial psychometric evaluation of the 24-item Computer-Based Prostate Cancer Screening Decision Aid Acceptance Scale among 357 African-American men. METHODS: Exploratory factor analysis (EFA) with maximum likelihood estimation and polychoric correlations followed by Promax and Varimax rotations. RESULTS: EFA yielded three factors: Technology Use Expectancy and Intention (16 items), Technology Use Anxiety (5 items), and Technology Use Self-Efficacy (3 items) with good to excellent internal consistency reliability at .95, .90, and .85, respectively. The standardized root mean square residual (0.035) indicated the factor structure explained most of the correlations. CONCLUSIONS: Findings suggest the three-factor, 24-item Computer-Based Prostate Cancer Screening Decision Aid Acceptance Scale has utility in determining the acceptance and use of CBDAs among African-American men at risk for prostate cancer. Future research is needed to confirm this factor structure among socio-demographically diverse African-Americans

    First geophysical investigations to study a fragile Pomor cultural heritage site at Russekeila – Kapp Linné), Svalbard

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    With climate warming, the cultural heritage sites of the Arctic are in great danger. Extensive research is needed to study such sites. The archaeological site at Russekeila – Kapp Linné, Svalbard was selected for the survey as previous research had highlighted its vulnerability to cryospheric hazards. The main objectives of the survey were (i) to register the precise surface and subsurface locations of cultural heritage (CH) (remains of an 18th century Russian Pomor trapper's hut) objects within the study area, (ii) to determine the impact of coastal erosion on the CH objects and (iii) to understand the near-surface stratigraphy of the site. The geophysical surveys were carried out using a Ground Penetrating Radar (GPR) instrument with two shielded antennas of 500 MHz and 800 MHz centre frequencies. Only weak anomalies were observed at the intersections with wooden drifts, which can be explained by the low contrast between the relative dielectric constant values of the driftwood and the background soil. The depth extent of the driftwood within the soil was understood from the processed GPR data to a depth of approximately 25 cm. A near-surface stratigraphy of the site morphology, including thaw depth, saturated and unsaturated sediments and soil cover, was established based on multiple reflectors observed to 2 m depth. Loose sediments are indicated by reflectors to a depth of approximately 20 cm. Unsaturated fine sediments, which show a stronger signal compared to the underlying saturated sand layers, can be observed from about 1.2 m depth. No reflectors are shown below the thaw depth.First geophysical investigations to study a fragile Pomor cultural heritage site at Russekeila – Kapp Linné), SvalbardpublishedVersio

    Poroelasticity is the dominant energy dissipation mechanism in cartilage at the nano-scale

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    Recent studies of micro- and nano-scale mechanics of cartilage and chondrocyte pericellular matrix have begun to relate matrix molecular structure to its mechanical response. AFM-based indentation has revealed rate-dependent stiffness at the micro-scale. While multi-scale elastic behavior has been studied, and poro-viscoelastic properties have been extensively documented at the tissue-level, time-dependent behavior and energy dissipation mechanisms of cartilage matrix at the nano-scale are not well understood. Here, we used AFM-based dynamic compression in conjunction with poroelastic finite element modeling to study the frequency-dependent behavior of cartilage using nano-scale oscillatory displacement amplitudes. We introduce the characteristic frequency f[subscript peak] at which the maximum energy dissipation occurs as an important parameter to characterize matrix time-dependent behavior. Use of micron-sized AFM probe tips with nano-scale oscillatory displacements over a 3-decade frequency range enabled clear identification of this characteristic frequency f[subscript peak]. The length-scale dependence of poroelastic behavior combined with judicious choice of probe tip geometry revealed flow-dependent and flow-independent behavior during matrix displacement amplitudes on the order of macromolecular dimensions and intermolecular pore-sizes.National Science Foundation (U.S.) (Grant CMMI-0758651)National Institutes of Health (U.S.) (National Institute of Arthritis and Musculoskeletal and Skin Diseases (U.S.) Grant AR33236

    Predictors of quality of life in HIV-infected rural women: Psychometric test of the Chronic Illness Quality of Life Ladder

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    The Chronic Illness Quality of Life Ladder (CIQOLL) underwent psychometric testing in a sample of 278 women with HIV disease. The CIQOLL, a self-anchoring striving scale based on Cantril’s Ladder, measures seven domains (physical , emotional, financial, family and friends, spiritual well-being, peace of mind, and overall life satisfaction) across four time periods (present, past, future, life without a diagnosis of HIV). The domains were derived from focus groups with persons with HIV disease. Women with a diagnosis of HIV Infection, age 18 or older, residing in rural areas in the southeastern United States, completed questionnaires that measured physical functioning, HIV related symptom frequency and distress, depressive symptoms, social support, and quality of life. Procedures used to assess reliability included item–item, item–total, and subscale–subscale correlations, and Chronbach’s coefficient a. Criterion-related (concurrent) validity was assessed by correlating the CIQOLL with HIV symptoms, functional status and social support. Construct validity was estimated using factor analysis and predictive modeling. Results provide preliminary evidence that the CIQOLL is a reliable and valid scale that may provide meaningful information about persons living with a chronic illness, such as HIV disease, especially low literacy and unacculturated populations. Additional research is needed to weight the domains, test the sensitivity of the scale to changes over time, and explore the usefulness of discrepancy scores

    Development and Psychometric Properties of a Prostate Cancer Knowledge Scale for African American Men

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    African American men have the highest prostate cancer-related mortality nationally. In response to this disparity, targeted interventions are emerging to enhance African American men\u27s prostate cancer (PrCA) knowledge to ensure they are equipped to make informed decisions about PrCA screening with health-care providers. African American men\u27s PrCA knowledge has been measured inconsistently over time with limited psychometric evidence. The factor structure of this construct in African American men is relatively unknown. This study describes the development and psychometric evaluation of an 18-item Prostate Cancer Knowledge Scale among 352 African American men. Exploratory factor analysis (EFA) was conducted using weighted least square mean and variance estimation with Geomin rotation. EFA yielded three factors: (6 items), (5 items), (7 items) with good internal consistency reliability at KR-20 = .80 for the total scale and .64, .66, and .75, respectively, for each subscale. Factor loadings ranged from .31 to .86. The standardized root mean square residual (0.08) indicated that the factor structure explained most of the correlations. The three-factor, 18-item Prostate Cancer Knowledge Scale demonstrates that PrCA knowledge is a multidimensional construct and has utility for reliably measuring PrCA knowledge among African American men. Future research is required to confirm this factor structure among socio-demographically diverse African Americans

    Novel Bacterial Cellulose/Gelatin Hydrogels as 3D Scaffolds for Tumor Cell Culture.

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    Three-dimensional (3D) cells in vitro culture are becoming increasingly popular in cancer research because some important signals are lost when cells are cultured in a two-dimensional (2D) substrate. In this work, bacterial cellulose (BC)/gelatin hydrogels were successfully synthesized and were investigated as scaffolds for cancer cells in vitro culture to simulate tumor microenvironment. Their properties and ability to support normal growth of cancer cells were evaluated. In particular, the human breast cancer cell line (MDA-MD-231) was seeded into BC/gelatin scaffolds to investigate their potential in 3D cell in vitro culture. MTT proliferation assay, scanning electron microscopy, hematoxylin and eosin staining and immunofluorescence were used to determine cell proliferation, morphology, adhesion, infiltration, and receptor expression. The in vitro MDA-MD-231 cell culture results demonstrated that cells cultured on the BC/gelatin scaffolds had significant adhesion, proliferation, ingrowth and differentiation. More importantly, MDA-MD-231 cells cultured in BC/gelatin scaffolds retained triple-negative receptor expression, demonstrating that BC/gelatin scaffolds could be used as ideal in vitro culture scaffolds for tumor cells

    Prevalence of human respiratory syncytial virus circulating in Iran

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    Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infection during early childhood and is associated with a great burden on patients, parents, and society. While no treatment is yet available, results from recent phase 2 clinical trials of cell-entry inhibitors and RSV vaccines are promising. To prepare for introduction of these novel therapeutics, good understanding of its molecular epidemiology and continuous RSV surveillance data are necessary. This paper provides an overview of RSV prevalence and genotype distribution in Iran from 1996 to 2013. This meta-analysis includes 21 published studies. In total, 775 (18.7) of 4140 respiratory specimens were positive for RSV infection. The male-female ratio of RSV-positive patients was 1.5:1. Significant peaks of RSV infection were detected during the cold season (November-March). RSV infection was mainly observed in patients <2 years of age. Phylogenetic studies showed that genotypes GA1, GA2, GA5, and BA co-circulated in Iran in 2007-2013. This review highlights the necessity of introducing standard molecular surveillance programs to inform the epidemiological, clinical, and pathological characteristics of various RSV genotypes. Improved understanding of the molecular epidemiology will be useful for development of novel RSV therapeutics. © 2015 King Saud Bin Abdulaziz University for Health Sciences

    Numerical analysis of shipping water impacting a step structure

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    Shipping water, the flow washing over and impacting the upper decks of ships and offshore structures, occurs frequently during their service life and often causes structural problems. For engineers to design safe floating structures subjected to shipping water it is essential to gain an in-depth understanding of its depth and flow field, and the resulting impact forces. In this work, Computational Fluid Dynamics (CFD) is applied to understand the physics of shipping water washing over a stepped platform. We find that the most accurate solutions are obtained with the turbulence closure. The hydrodynamic load generated by the shipping water is found to strongly depends on the kinematic energy of the water hitting the step. It is shown that with smaller values of the freeboard a more dynamic flow ensues, with a stronger vortex and larger velocity gradient resulting in deeper shipping water and a larger impact force
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