926 research outputs found

    Application of hyperbaric oxygen in bone tissue engineering : effect of hyperbaric oxygen treatment on bone marrow stem cells

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    and non-union of bony fractures has been proposed since 1966, little has been known about the effect of HBOT on bone marrow stem cells (BMSC). The aim of this study is to investigate the effect of HBO treatment on osteogenetic differentiation of BMSC and potential application in bone tissue engineering. Adhesive stromal cells harvested from bone marrow were characterized by mesenchymal differentiation potential, cell surface markers and their proliferation capacity. Mesenchymal stem cells, which demonstrated osteogenic, chondrogenic and adipogenic differentiation potential and expressed positively for CD 29, CD 44, CD 73, CD 90, CD 105, CD 166 and negatively for CD34 and CD 45, were selected and treated in a laboratory-scale HBO chamber using different oxygen pressures and exposure times. No obvious effect of HBO treatment on BMSC proliferation was noticed. However, cytotoxic effects of HBO were considerably less pronounced when cells were cultured in medium supplemented with 10% FBS in comparison to medium supplemented with 2% FCS, as was evaluated by WST-1 assay. Under HBO treatment, bone nodules were formed in three days, which was clearly revealed by Von Kossa staining. In contrasts, without HBO treatment, bone nodules were not detected until 9-12 days using the same inducing culture media. Calcium deposition was also significantly increased after three days of HBO treatments compared to no HBO treatment. In addition it was also found that oxygen played a direct role in the enhancement of BMSC osteogenic differentiation, which was independent of the effect of air pressure

    Using Intervention Mapping to Develop an Efficacious Multicomponent Systems-Based Intervention to Increase Human Papillomavirus (HPV) Vaccination in a Large Urban Pediatric Clinic Network

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    Background: The CDC recommends HPV vaccine for all adolescents to prevent cervical, anal, oropharyngeal, vaginal, vulvar, and penile cancers, and genital warts. HPV vaccine rates currently fall short of national vaccination goals. Despite evidence-based strategies with demonstrated efficacy to increase HPV vaccination rates, adoption and implementation of these strategies within clinics is lacking. The Adolescent Vaccination Program (AVP) is a multicomponent systems-based intervention designed to implement five evidence-based strategies within primary care pediatric practices. The AVP has demonstrated efficacy in increasing HPV vaccine initiation and completion among adolescents 10-17 years of age. The purpose of this paper is to describe the application of Intervention Mapping (IM) toward the development, implementation, and formative evaluation of the clinic-based AVP prototype. Methods: Intervention Mapping (IM) guided the development of the Adolescent Vaccination Program (AVP). Deliverables comprised: a logic model of the problem (IM Step 1); matrices of behavior change objectives (IM Step 2); a program planning document comprising scope, sequence, theory-based methods, and practical strategies (IM Step 3); functional AVP component prototypes (IM Step 4); and plans for implementation (IM Step 5) and evaluation (IM Step 6). Results: The AVP consists of six evidence-based strategies implemented in a successful sequenced roll-out that (1) established immunization champions in each clinic, (2) disseminated provider assessment and feedback reports with data-informed vaccination goals, (3) provided continued medical and nursing education (with ethics credit) on HPV, HPV vaccination, message bundling, and responding to parent hesitancy, (4) electronic health record cues to providers on patient eligibility, and (5) patient reminders for HPV vaccine initiation and completion. Conclusions: IM provided a logical and systematic approach to developing and evaluating a multicomponent systems-based intervention to increase HPV vaccination rates among adolescents in pediatric clinics

    Pilot study conducted on Exeter PMMA cement reamer

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    Pilot study and critical appraisal of the prototype Exeter PMMA Cement Reamer conducted in order to determine potential applications and improvements to design

    Association of the built environment with physical activity and adiposity in rural and urban youth

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    To determine if: (1) differences exist for body mass index (BMI) and moderate-to-vigorous physical activity (MVPA) between rural and urban youth, and (2) perceived and objective measures of environmental supports for physical activity differentially correlate with BMI and MVPA in middle school rural and urban youth

    Metal ion levels post primary unilateral total knee arthroplasty

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    BackgroundMetal ion release from metal implants through the processes of mechanical wear and corrosion has been one of the main concerns post total joint arthroplasty. However, there have been very few studies to show metal ion exposure post total knee implants.AimsThe aim of this study was to investigate whether blood metal ion levels are raised in patients with well-functioning unilateral primary total knee arthroplasty in the short and the long term after surgery.Methods Whole blood Chromium and serum Cobalt levels were measured in 22 patients following primary total knee arthroplasty at a minimum of 12 months after surgery and then repeated at a mean of four years. Eleven patients had the cemented triathlon knee system and 11 patients had an uncemented ACS knee system with multilayer coatings.Results Cobalt levels in our study are low one year after TKR and stayed within normal limits with no significant rise at four years (p=0.300). Chromium levels raised significantly by four years (p=0.007), but remained within normal range with no evidence of toxic systemic effects. Our data showed no statistically significant difference for cobalt and chromium levels between ACS and Triathlon groups (p=0.62; p=0.54 respectively).ConclusionAt an average of 50-months post well-functioning total knee arthroplasty, whole blood Chromium levels and serum Cobalt levels are within the normal range. The use of cement is unlikely to influence metal ion release and titanium nitride coating did not influence metal ion release from TKR implants

    Increasing HPV Vaccination in a Network of Pediatric Clinics using a Multi-component Approach

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    Background: Despite continued public health efforts to increase human papillomavirus (HPV) vaccination among adolescents, initiation remains below the level needed to reach the Healthy People 2020 goal of 80% series completion by age 13. Methods: We developed, implemented, and evaluated a multi-component program that used evidence-based strategies to increase HPV vaccine initiation in a network of 51 pediatric clinics in Houston, Texas. Our target populations were the clinic network, healthcare providers, male and female patients ages 11-17, and their parents. The program, called the Adolescent Vaccination Program (AVP), was conducted from March 2016 through March 2019 and contained strategies to increase vaccination including: HPV immunization champions; provider assessment and feedback; provider continuing education; provider reminders; and patient reminders. We used a single group pre/post design with an external comparison – NIS-Teen. Our primary outcome was initiation of the HPV vaccine based on the electronic health record. We used interrupted time series analysis (ITSA) to measure change in initiation over time. We calculated monthly, quarterly, and annual rates of initiation for each physician, clinic, and the network. We examined patterns of initiation by patient age, sex, race/ethnicity, and type of insurance. Results: By the end of the project, the 51 clinics averaged 77.4% initiation. Rates increased annually from September 2015 through March 2019. ITSA analysis over 75 months showed an increase in vaccine initiation of 0.396% per month from the introduction of the program in March 2016. Average individual clinic improvement was 0.37% per month ranging from -0.04% to 0.68% through March 2019. Data for the 11-12 year olds, the target age group for initiating the vaccine, showed a greater percentage increase (54.2%) compared with the 13-17 year olds (29.6%). Hispanics and African Americans had the highest initiation rates in all years while non-Hispanic whites had the lowest. Families without insurance had the lowest rates while those with Medicaid/Medicare had the highest. Conclusions: We observed a secular trend upward in both the network and NIS-Teen data; however, the network showed a steeper increase. The AVP is a promising program of strategies to increase HPV vaccination in a clinic setting

    Mortality and implant survival with simultaneous and staged bilateral total knee arthroplasty experience from the Australian Orthopaedic Association National Joint Replacement Registry

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    BACKGROUND: Total knee arthroplasty (TKA) is an effective procedure for relieving pain and restoring function in osteoarthritis, with a significant proportion of patients having severe disease bilaterally. However, although there are differences in patient selection criteria for bilateral procedures, there is no consensus regarding the optimal timing for bilateral TKA. The aim of this study was to compare rates and causes of revision and 30-day mortality between simultaneous and staged bilateral TKA using data from the Australian Orthopaedic Association National Joint Replacement Registry. METHODS: Data for over 36,000 bilateral TKAs were collected from September 1999 to December 2015. Rates and causes of revision and 30-day mortality rates were obtained for simultaneous bilateral and staged procedures with intervals of 1 day-6 weeks, 6 weeks-3 months, and 3-6 months. Yearly cumulative percent revision or cumulative percent survival with 95% confidence intervals calculated using the Kaplan-Meier method and adjusted hazard ratios were used for comparisons. RESULTS: There was no significant difference between revision rates or reasons for revision between staged bilateral and simultaneous TKA (hazard ratio 1.09 [95% confidence interval {CI} 0.85-1.40; P = .511] for 1 day-6 weeks, 0.93 [95% CI 0.77-1.14; P = .494] for 6 weeks-3 months, and 1.10 [95% CI 0.98-1.23; P = .115] for 3-6 months). The most common reasons for revision were loosening/lysis and infection. The 30-day mortality rates were lower in the 6 weeks-3 months group than simultaneous bilaterals (P = .007). CONCLUSION: This study demonstrates that simultaneous and staged bilateral TKA have similar rates of revision over the medium term but that 30-day mortality is reduced in the 6 weeks-3 months group

    Social origin and the financial feasibility of going to university: the role of wage penalties and availability of funding

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    The evidence on why students from lower social origin are persistently underrepresented in higher education (HE) suggests social, educational and economic factors all play a role. We concentrate on the influence of monetary costs/benefits and how these are influenced by social origin. In particular, we consider the effect of a class-based wage penalty in the labour market and, using evidence from a large-scale survey of Scottish students, we show how the greater financial constraints facing working-class students affects the incentive to participate in HE. Using a simple model of human capital investment, the low rate of working-class participation in HE is shown to be consistent with rational behaviour, i.e. weighing the monetary costs and benefits, participating in HE is a less attractive investment proposition for some students. We conduct simulations which suggest this could be mitigated by generous income-contingent support

    Systematic Cu-63 NQR studies of the stripe phase in La(1.6-x)Nd(0.4)Sr(x)CuO(4) for 0.07 <= x <= 0.25

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    We demonstrate that the integrated intensity of Cu-63 nuclear quadrupole resonance (NQR) in La(1.6-x)Nd(0.4)Sr(x)CuO(4) decreases dramatically below the charge-stripe ordering temperature T(charge). Comparison with neutron and X-ray scattering indicates that the wipeout fraction F(T) (i.e. the missing fraction of the integrated intensity of the NQR signal) represents the charge-stripe order parameter. The systematic study reveals bulk charge-stripe order throughout the superconducting region 0.07 <= x <= 0.25. As a function of the reduced temperature t = T/T(charge), the temperature dependence of F(t) is sharpest for the hole concentration x=1/8, indicating that x=1/8 is the optimum concentration for stripe formation.Comment: 10 pages of text and captions, 11 figures in postscript. Final version, with new data in Fig.

    To the Continuum and Beyond: Structure of U Nuclei

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    An experiment was performed at the 88-inch cyclotron at LBNL to investigate the structure of uranium isotopes and concurrently test the so-called surrogate ratio method. A 28 MeV proton beam was used to bombard 236U and 238U targets and the outgoing light ions were detected using the STARS silicon telescope allowing isotopic assignments and the excitation energy of the compound nucleus to be measured. A fission detector was placed at backward angles to give particle-fission coincidences, while the six clover germanium detectors of the LIBERACE array were used for particle-γ coincidences. The (p,d) reaction channels on 236U and 238U targets were used as a surrogate to measure the σ(234U(n,f))/σ(236U(n,f)) cross section ratio. The results give reasonable agreement with literature values over an equivalent neutron energy range between 0 MeV and 6 MeV. Structure results in 235U include a new (3/2−) level at 1035 keV, that is tentatively assigned as the 3/2−[501] Nilsson state. The analogue 3/2−[501] state in 237U may be associated with a previously observed level at 1201 keV, whose spin/parity is restricted to Jπ = 3/2− on the basis of newly observed decays to the ground band
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