1,250 research outputs found

    Temperature dependence of Raman vibrational bandwidths in poly(rA) and rAMP

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    Isotropic and anisotropic spontaneous Raman spectra were obtained from solutions of poly(ra) and rAMP in buffer. The temperature dependence of these spectra was measured to elucidate the influence of macromolecular dynamics and solvent dynamics on the bandwidths of base vibrations in the single stranded polynucleotide poly(rA). The temperature dependence of a bandwidth depends upon the particular vibration under study. The bands can for the larger part be described by Lorentz functions. When fitted by Voigt functions, maximally 10% of each bandprofile of the adenine base vibrations can be attributed to a Gaussian component. The second moment has been determined from the spectra for the 725 cm¿1 band. From the second moment and the bandwidth, we were able to deduce that the vibrational oscillator is in the fast modulation limit. The determined timescale (perturbation correlation time 0.13 ps) eliminate perturbations connected to long range diffusion like concentration fluctuations (timescale in the order of 10 ps). The spectra were analyzed by an extensive curve fitting procedure providing accurate bandparameters (position, width and integrated intensity). The 725 cm¿1 band of adenine has a bandwidth which is dependent upon the degree of polymerization. In RAMP it is 17.6 cm¿1, in stacked (i.e. low temperature 5°C) poly(rA) it is 11.5 cm¿1. The bandwidth of the adenine vibration at 1336 cm¿1 cm¿1 has a temperature dependence which is similar to the intensity changes of the Raman and the absorption hypochromic effect as a function of temperature. The melting transition can therefore be followed by the changes in bandwidth of suitable vibrations

    Building Collaborative Partnerships to Increase Postsecondary Education Opportunities for Students with Intellectual and Developmental Disabilities

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    Transitioning from high school to the next phase of life can be especially challenging for youth with intellectual and other developmental disabilities (IDD). Federal mandates are in place to provide individualized transition services to students with disabilities up to age 22; however, there is variability in the location of service delivery. A growing number of school districts have partnered with institutions of higher education (IHE) in an effort to enhance postsecondary education (PSE) opportunities for individuals with IDD who are between the ages of 18-21. While there are some differences in PSE programs, the core foundational component is constant across models: establishing and maintaining collaborative partnerships between school districts and IHE. This paper describes PSE program models and highlights the necessity to continue to build partnerships in an effort to expand PSE opportunities for young adults with IDD

    Effective treatment of liver metastases with photodynamic therapy, using the second-generation photosensitizer meta-tetra(hydroxyphenyl)chlorin (mTHPC), in a rat model

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    The only curative treatment for patients with liver metastases to date is surgery, but few patients are suitable candidates for hepatic resection. The majority of patients will have to rely on other treatment modalities for palliation. Photodynamic therapy (PDT) could be a selective, minimally invasive treatment for patients with liver metastases. We studied PDT in an implanted colon carcinoma in the liver of Wag/Rij rats, using the photosensitizer meta-tetra(hydroxyphenyl)chlorin (mTHPC). mTHPC tissue kinetics were studied using ex vivo extractions and in vivo fluorescence measurements. Both methods showed that mTHPC kinetics were different for liver and tumour tissue. After initial high levels at 4 h after administration (0.1 and 0.3 mg kg−1) mTHPC in liver tissue decreased rapidly in time. In tumour tissue no decrease in photosensitizer levels occurred, with mTHPC remaining high up to 48 h after administration. Both concentration data and fluorescence data showed an increase in tumour to liver ratios of up to 6.3 and 5.0 respectively. Illumination with 652 nm (15 J) resulted in extensive damage to tumour tissue, with necrosis of up to 13 mm in diameter. Damage to normal liver tissue was mild and transient as serum aspartate aminotransferase and alanine aminotransferase levels normalized within a week after PDT treatment. Long-term effects of mTHPC-PDT were studied on day 28 after treatment. Regardless of drug dose and drug–light interval, PDT with mTHPC resulted in complete tumour remission in 27 out of 31 treated animals (87%), with only four animals in which tumour regrowth was observed. Non-responding tumours proved to be significantly larger (P < 0.001) in size before PDT treatment. This study demonstrates that mTHPC is retained in an intrahepatic tumour and that mTHPC-PDT is capable of inducing complete tumour remission of liver tumours. © 1999 Cancer Research Campaig

    Measuring teaching skills in elementary education using the Rasch model

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    Observation scales for measuring teaching skills were developed for both elementary education and kindergarten. Based on 500 observations, we found that both scales meet the requirements of the dichotomous Rasch model. These observation scales can help in finding the zone of proximal development of teachers in elementary education and kindergarten. This can help in improving teachers' skills

    Predictors of Hospitals with Endemic Community-Associated Methicillin-Resistant Staphylococcus aureus

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    OBJECTIVE: We sought to identify hospital characteristics associated with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carriage among inpatients. DESIGN: Prospective cohort study. SETTING: Orange County, California. PARTICIPANTS: Thirty hospitals in a single county. METHODS: We collected clinical MRSA isolates from inpatients in 30 of 31 hospitals in Orange County, California, from October 2008 through April 2010. We characterized isolates by spa typing to identify CA-MRSA strains. Using California’s mandatory hospitalization data set, we identified hospital-level predictors of CA-MRSA isolation. RESULTS: CA-MRSA strains represented 1,033 (46%) of 2,246 of MRSA isolates. By hospital, the median percentage of CA-MRSA isolates was 46% (range, 14%–81%). In multivariate models, CA-MRSA isolation was associated with smaller hospitals (odds ratio [OR], 0.97, or 3% decreased odds of CA-MRSA isolation per 1,000 annual admissions; P < .001), hospitals with more Medicaid-insured patients (OR, 1.2; P = .002), and hospitals with more patients with low comorbidity scores (OR, 1.3; P < .001). Results were similar when restricted to isolates from patients with hospital-onset infection. CONCLUSIONS: Among 30 hospitals, CA-MRSA comprised nearly half of MRSA isolates. There was substantial variability in CA-MRSA penetration across hospitals, with more CA-MRSA in smaller hospitals with healthier but socially disadvantaged patient populations. Additional research is needed to determine whether infection control strategies can be successful in targeting CA-MRSA influx

    White Rabbit Applications for FAIR Experiments

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    The Effects of Long-Term Graft Preservation on Intraoperative Hemostatic Changes in Liver Transplantation

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    We compared hemostatic changes during OLT and HLT after various periods of graft storage, to investigate whether the host liver in HLT protects the recipient from hemostatic deterioration induced by severe graft storage damage. In particular, the mechanism of fibrinolytic deterioration was investigated. The effect of prostaglandin E1 (PGE1) on these parameters was also studied
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