76 research outputs found

    Time-resolved propagation of polarized light in turbid media: experiment and theory

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    This paper presents our study of time-resolved propagation of polarized light in scattering media. Monte Carlo simulated time-resolved Stokes vectors of transmitted light were compared with the experimental results. A satisfying match has been obtained

    Polarization-gated imaging techniques based on time-resolved Stokes vectors for filament tissues

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    We report the discovery of using various time-resolved Stokes vector components for more efficient imaging of filament tissues. In particular, the Stokes vector components S2 and S3 were found more useful, compared with the other two components. The time-resolved Stokes vectors of signals transmitting chicken breast tissue, mouse cardiac muscle tissue, and polystyrene micro-sphere solution are compared. A target of chicken bone in chicken breast tissue is used for demonstrating the effectiveness of various Stokes vector components for imaging purpose. Also, Monte Carlo simulations were conducted for comparison

    Study of polarization evolution in phantom tissues with ultrafast optics techniques: Monte Carlo simulations and experiments

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    This paper presents our study results of polarized short pulse transmission through phantom tissues made of polystyrene particle solutions with various concentrations and particle sizes. To improve the quality of optical imaging using an ultrafast light source, study is required to fully understand the evolution of the polarization state in the sample, as well as the time- and polarization-dependent distributions of optical intensity exiting from samples. Temporal profiles of the Stokes vectors and the degree of polarization are measured experimentally. The results agree well with those resulting from Monte Carlo simulations. Analyses based on the Stokes-Mueller formalism show that the first scattering event determines the spatial patterns of the transmitted Stokes vectors. When a detected area at the output surface of the sample is symmetric about the incident beam, the temporal profile of transmittance is independent of the incident polarization state. The linear relationship between the average order of scatters and the light propagation time can be used to explain the exponential decay of the degree of polarization and the inversely proportional relationship between the FWHM of the degree of polarization and the scatterer concentration

    Polarization-gated imaging techniques based on time-resolved Stokes vectors for filament tissues

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    We report the discovery of using various time-resolved Stokes vector components for more efficient imaging of filament tissues. In particular, the Stokes vector components S2 and S3 were found more useful, compared with the other two components. The time-resolved Stokes vectors of signals transmitting chicken breast tissue, mouse cardiac muscle tissue, and polystyrene micro-sphere solution are compared. A target of chicken bone in chicken breast tissue is used for demonstrating the effectiveness of various Stokes vector components for imaging purpose. Also, Monte Carlo simulations were conducted for comparison

    Preclinical Evaluation on the Tumor Suppression Efficiency and Combination Drug Effects of Fermented Wheat Germ Extract in Human Ovarian Carcinoma Cells

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    Fermented wheat germ extract (FWGE) is a nutrient supplement and a potential antitumor ingredient for developing an integrated chemotherapy with standard chemotherapeutic drugs for treating ovarian cancer patients. In this study, we evaluated the tumor suppression efficiency of FWGE in human ovarian carcinoma cells, SKOV-3 and ES-2, and found the half-maximal inhibitory concentrations (IC50s) to be 643.76 μg/mL and 246.11 μg/mL after 48 h of FWGE treatment. FWGE treatment also induced programmed cell death by activating the caspase-7 cleavage in both SKOV-3 and ES-2 cells, but only caspase-3 and poly(adenosine diphosphate-ribose) polymerase cleavages were activated in SKOV-3 cells. Moreover, FWGE exhibited combination drug effects with cisplatin and docetaxel in SKOV-3 and ES-2 cells by enhancing the cytotoxicity of both drugs. In conclusion, we found that FWGE not only suppressed cell growth but also induced caspase-3-related and caspase-7-related cell death in human ovarian carcinoma cells. FWGE treatment further enhanced the cytotoxicity of cisplatin and docetaxel, suggesting that FWGE is a potential ingredient in the development of adjuvant chemotherapy with cisplatin or docetaxel for treating ovarian cancer patients

    Void Structures in Regularly Patterned ZnO Nanorods Grown with the Hydrothermal Method

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    The void structures and related optical properties after thermal annealing with ambient oxygen in regularly patterned ZnO nanrorod (NR) arrays grown with the hydrothermal method are studied. In increasing the thermal annealing temperature, void distribution starts from the bottom and extends to the top of an NR in the vertical (c-axis) growth region. When the annealing temperature is higher than 400°C, void distribution spreads into the lateral (m-axis) growth region. Photoluminescence measurement shows that the ZnO band-edge emission, in contrast to defect emission in the yellow-red range, is the strongest under the n-ZnO NR process conditions of 0.003 M in Ga-doping concentration and 300°C in thermal annealing temperature with ambient oxygen. Energy dispersive X-ray spectroscopy data indicate that the concentration of hydroxyl groups in the vertical growth region is significantly higher than that in the lateral growth region. During thermal annealing, hydroxyl groups are desorbed from the NR leaving anion vacancies for reacting with cation vacancies to form voids

    Exploring factors influencing the work-related morale for certified nursing assistants in hospice care: A structural equation modeling study.

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    BACKGROUND:Certified nursing assistants (CNAs) in palliative care units often encounter the death of patients and undergo emotional burdens because of their altruistic practices. However, the influences of altruism and perceptions of death on the work morale of CNAs remain unclear. The fact that morale can be improved by modifying related factors justifies the necessity of a theoretical model of morale for CNAs. However, such a model is currently absent. Based on relevant literature, factors including altruism, social support, perceptions of death, and job satisfaction are related to morale through the mediation of job stress. AIM:This study was aimed toward determining the influencing factors and developing a structural model of morale with regard to CNAs working in palliative care units. DESIGN:The hypothesized model was tested in a cross-sectional design with structural equation modeling using AMOS 23. SETTING/PARTICIPANTS:A total of 413 CNAs from five hospice units in Taiwan participated in the survey. RESULTS:Goodness-of-fit indexes, including χ2/DF = 2.187, PGFI = 0.461, and PNFI = 0.462, among others, confirmed the modified model fit the data well. Altruism, social support, perceptions of death, and job satisfaction were negatively related to job stress (-0.238, -0.196, -0.204, and -0.131, respectively). Altruism and social support positively affected job satisfaction (0.635 and 0.553). Factors directly affecting morale included altruism, social support, job stress, and job satisfaction (0.837, 0.711, -0.244, and 0.540, respectively). The relationship between altruism and morale was the strongest among all the direct paths toward morale. Job stress was the major mediator in these relationships. CONCLUSION:Altruism is imperative for morale. The confirmed model is called the Five Constructs to Morale (5CM) model. These findings indicate the need to assess the levels of altruism and perceptions of death during the recruitment of CNAs. From the perspective of human resource management and organizational behavior, CNAs with a high level of altruism and a positive attitude toward death assure the well-being of end of life patients because of work involvement and commitment to the challenging work of hospice care. The cultivation of a supportive environment and coping strategies are suggested for the management of CNAs facing patient death. Hospice care decision makers should carefully assess morale levels among health professionals by applying the 5CM model. Identifying modifiable factors that can improve morale among nursing staff in hospice care to ensure work fulfillment and quality care merits emphasis in clinical practice. The establishment of effective strategies to facilitate the work morale of nursing staff is suggested for palliative care units. Morale improvement related task should be a global public health priority
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