5 resultados para Other Analytical, Diagnostic and Therapeutic Techniques and Equipment

em Bucknell University Digital Commons - Pensilvania - USA


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Background: UV exposure causes a wide range of skin damage including cutaneous melanoma. The mechanisms of cellular and molecular damage as well as erythemal and pigmentation responses to UV exposure have largely been studied in the White population. Methods: This study systematically investigates responses to UV exposure in the Native Hawaiian and Pacific Islanders (NHPI) and Asian populations living in Hawai’i (A/HI) as well as in Asians living in Maryland (A/MD). Results: Our analyses indicate that the NHPI population is less sensitive to UV exposure than the A/HI population. Comparisons between the two Asian groups suggest that, despite slightly but not statistically different baseline constitutive pigmentation (pre-UV exposure), the A/HI and A/MD had similar UV sensitivity, measured as minimal erythemal dose (MED). However, the A/MD population had higher levels of oxy-hemoglobin at doses of 2.0, 2.8 and 4.0 MED. Unexpectedly the A/MD subjects retained higher levels of pigmentation 2 weeks post UV exposure. Conclusion: This study provides insight into UV responses of the inhabitants of Hawai’i and shows that such responses are statistically significant for relatively small samples of Native Hawaiian and Pacific Islanders, and for Asians living in Hawai’i and Asians living in Maryland.

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Biodegradable polymer nanoparticles have the properties necessary to address many of the issues associated with current drug delivery techniques including targeted and controlled delivery. A novel drug delivery vehicle is proposed consisting of a poly(lactic acid) nanoparticle core, with a functionalized, mesoporous silica shell. In this study, the production of PLA nanoparticles is investigated using solvent displacement in both a batch and continuous manner, and the effects of various system parameters are examined. Using Pluronic F-127 as the stabilization agent throughout the study, PLA nanoparticles are produced through solvent displacement with diameters ranging from 200 to 250 nm using two different methods: dropwise addition and in an impinging jet mixer. The impinging jet mixer allows for easy scale-up of particle production. The concentration of surfactant and volume of quench solution is found to have minimal impact on particle diameter; however, the concentration of PLA is found to significantly impact the diameter mean and polydispersity. In addition, the stability of the PLA nanoparticles is observed to increase as residual THF is evaporated. Lastly, the isolated PLA nanoparticles are coated with a silica shell using the Stöber Process. It is found that functionalizing the silica with a phosphonic silane in the presence of excess Pluronic F-127 decreases coalescence of the particles during the coating process. Future work should be conducted to fine-tune the PLA nanoparticle synthesis process by understanding the effect of other system parameters and in synthesizing mesoporous silica shells.

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Nursing homes have been criticized for frequent use and possible misuse of psycho-active agents. These issues are of clinical concern and policy relevance, especially since the passage of the Omnibus Budget Reconciliation Act (OBRA) of 1987. Using a sample of 419 residents, the authors examined the relationships among antipsychotic drug (AP) use, behavior, and mental health diagnoses. Only 23.2% of the residents were administered APs on a routine and/or "as-needed" basis. Based on the Multidimensional Observation Scale for Elderly Subjects (MOSES) ratings, AP users were more irritable, disoriented, and withdrawn than were nonusers. Also, AP users demonstrated agitated behaviors more frequently. Notably, AP users and nonusers differed significantly in terms of documented mental health diagnoses. Among AP users, 70.1% had documented dementia, 8.3% were psychotic or had other psychiatric disorders, and 21.6% had no mental health diagnoses. In contrast, the majority of nonusers had no mental health disorders. Logistic regression revealed that diagnostic factors, frequency of agitation, level of withdrawal, and marital status were significant predictors of AP use.