Phase equilibrium temperature and dissociation enthalpy in the tri-n-butylalkylphosphonium bromide semiclathrate hydrate systems

Semiclathrate hydrate (SCH) is one of the phase change materials suitable for cold storage. The thermodynamic properties of SCHs, such as an equilibrium temperature and a dissociation enthalpy, depend on the size and shape of guest substances. In this study, to reveal the effect of cation size and shape on the thermodynamic properties, tri-n-butylalkylphosphonium bromide (P444R-Br) SCHs, where the alkyl group was n-propyl (R = 3), n-butyl (R = 4), n-pentyl (R = 5), i-butyl (R = i-4), i-pentyl (R = i-5), or allyl (R = Al)), were investigated. The branched alkyl groups (R = i-4 or i-5) raised the equilibrium temperature, whereas the shorter alkyl groups (R = 3 or Al) lowered one. Except for P4445-Br and P444(Al)-Br SCHs, the other P444R-Br SCHs had the same orthorhombic structure. Among the orthorhombic systems in the present study, the semiclathrate hydrate with a higher equilibrium temperature had a larger dissociation enthalpy

Phase Equilibrium Relations of Semiclathrate Hydrates Based on Tetra- n-butylphosphonium Formate, Acetate, and Lactate

Phase equilibrium (temperature-composition) relations of tetra-n-butylphosphonium formate (TBP-For), acetate (TBP-Ace), and lactate (TBP-Lac) semiclathrate hydrate systems have been measured. The highest equilibrium temperatures of TBP-For, TBP-Ace, and TBP-Lac semiclathrate hydrates were 280.9, 284.6, and 283.8 K at the atmospheric pressure, respectively, where the composition of tetra-n-butylphosphonium carboxylate was approximately 0.035 ± 0.001 (mole fraction) in every system. The dissociation enthalpies of tetra-n-butylphosphonium carboxylate semiclathrate hydrates were measured by differential scanning calorimetry. The dissociation enthalpies of TBP-For, TBP-Ace, and TBP-Lac semiclathrate hydrates were (187 ± 3), (193 ± 3), and (177 ± 3) J·g-1, respectively.Jin Shimada, Masami Shimada, Takeshi Sugahara, et al. Phase Equilibrium Relations of Semiclathrate Hydrates Based on Tetra-n-butylphosphonium Formate, Acetate, and Lactate. Journal of Chemical & Engineering Data, 63 (9), 3615-3620, September 13, © 2018 American Chemical Society. https://doi.org/10.1021/acs.jced.8b0048

A Disseminated Fusarium fujikuroi Species Complex Infection Prior to Allogeneic Hematopoietic Stem Cell Transplantation

A 53-year-old man was diagnosed with acute myeloid leukemia, which was refractory to chemotherapies. Systemic papules appeared afterward. The skin biopsies revealed filamentous fungal infection including fusariosis. Despite antifungal therapy, the infection did not resolve, because neutropenia persisted with the leukemia. He underwent hematopoietic stem cell transplantation (HSCT) to overcome the leukemia and restore normal hematopoiesis but died from fusariosis just before engraftment. Fusarium fujikuroi species complex was detected in blood cultures with poor antifungal susceptibility. Because restoring normal hematopoiesis is important in the treatment of fusariosis, HSCT might be considered for patients with persistent pancytopenia

Filmless versus film-based systems in radiographic examination costs: an activity-based costing method

Background: Since the shift from a radiographic film-based system to that of a filmless system, the change in radiographic examination costs and costs structure have been undetermined. The activity-based costing (ABC) method measures the cost and performance of activities, resources, and cost objects. The purpose of this study is to identify the cost structure of a radiographic examination comparing a filmless system to that of a film-based system using the ABC method. Methods: We calculated the costs of radiographic examinations for both a filmless and a film-based system, and assessed the costs or cost components by simulating radiographic examinations in a health clinic. The cost objects of the radiographic examinations included lumbar (six views), knee (three views), wrist (two views), and other. Indirect costs were allocated to cost objects using the ABC method. Results: The costs of a radiographic examination using a filmless system are as follows: lumbar 2,085 yen; knee 1,599 yen; wrist 1,165 yen; and other 1,641 yen. The costs for a film-based system are: lumbar 3,407 yen; knee 2,257 yen; wrist 1,602 yen; and other 2,521 yen. The primary activities were "calling patient," "explanation of scan," " take photographs," and "aftercare" for both filmless and film-based systems. The cost of these activities cost represented 36.0% of the total cost for a filmless system and 23.6% of a film-based system. Conclusions: The costs of radiographic examinations using a filmless system and a film-based system were calculated using the ABC method. Our results provide clear evidence that the filmless system is more effective than the film-based system in providing greater value services directly to patients

Behavioral Analysis of Visitors to a Medical Institution's Website Using Markov Chain Monte Carlo Methods

Background: Consistent with the "attention, interest, desire, memory, action" (AIDMA) model of consumer behavior, patients collect information about available medical institutions using the Internet to select information for their particular needs. Studies of consumer behavior may be found in areas other than medical institution websites. Such research uses Web access logs for visitor search behavior. At this time, research applying the patient searching behavior model to medical institution website visitors is lacking. Objective: We have developed a hospital website search behavior model using a Bayesian approach to clarify the behavior of medical institution website visitors and determine the probability of their visits, classified by search keyword. Methods: We used the website data access log of a clinic of internal medicine and gastroenterology in the Sapporo suburbs, collecting data from January 1 through June 31, 2011. The contents of the 6 website pages included the following: home, news, content introduction for medical examinations, mammography screening, holiday person-on-duty information, and other. The search keywords we identified as best expressing website visitor needs were listed as the top 4 headings from the access log: clinic name, clinic name + regional name, clinic name + medical examination, and mammography screening. Using the search keywords as the explaining variable, we built a binomial probit model that allows inspection of the contents of each purpose variable. Using this model, we determined a beta value and generated a posterior distribution. We performed the simulation using Markov Chain Monte Carlo methods with a noninformation prior distribution for this model and determined the visit probability classified by keyword for each category. Results: In the case of the keyword "clinic name," the visit probability to the website, repeated visit to the website, and contents page for medical examination was positive. In the case of the keyword "clinic name and regional name," the probability for a repeated visit to the website and the mammography screening page was negative. In the case of the keyword "clinic name + medical examination," the visit probability to the website was positive, and the visit probability to the information page was negative. When visitors referred to the keywords "mammography screening," the visit probability to the mammography screening page was positive (95% highest posterior density interval = 3.38-26.66). Conclusions: Further analysis for not only the clinic website but also various other medical institution websites is necessary to build a general inspection model for medical institution websites; we want to consider this in future research. Additionally, we hope to use the results obtained in this study as a prior distribution for future work to conduct higher-precision analysis

Analysis of Factors Inhibiting the Dissemination of Telemedicine in Japan : Using the Interpretive Structural Modeling

Background:Telemedicine is not significantly spreading globally and large variations in its availability and use exist internationally. Although many factors already inhibit the dissemination of telemedicine, its complexly intertwined factors make it more difficult to solve this problem. This study aimed to analyze and visualize relationships among factors inhibiting the dissemination of telemedicine. We applied the interpretive structural modeling method and cross-impact matrix multiplication applied to classification analysis. Materials and Methods:Factors inhibiting the dissemination of telemedicine in Japan were extracted by literature review and hearing from four medical informatics experts belonging to a university or hospital using the Kawakita Jiro method. Results:Eighteen factors were extracted as those inhibiting the dissemination of telemedicine service in Japan: initial and operation cost, research data, legal development, profitability, usability, human resources, image quality, network speed, information security, technical limitation, restriction for clinical practice, practice continuity, target use case, burden for physicians, respondence, risks for clinical safety, understanding of medical staff, and understanding of patients. The hierarchical structure chart showed a nine-level structure and the cross-impact matrix showed the relationship among factors and the classification of them inhibiting the dissemination of telemedicine. Discussion:We found that the underlying factors were high implementation and operation costs, low research data, and risks for clinical safety. Implementation and operation costs, research data, legal development, and profitability have high driving power; thus, it is expected that the elimination of these inhibiting factors would lead to the dissemination of telemedicine. Conclusions:There are many kinds of factors inhibiting the dissemination of telemedicine in Japan. The result of this showed the structure of these factors visually and could be useful to solve the problem inhibiting the dissemination of telemedicine effectively and efficiently

Study on the Preparation, Photophysics and Photostability of J-aggregate Thin Films of Cyanine Dyes

学位記番号：工博甲34

Penetration factors and introduction possibility for image diagnostic equipment

Background: This study investigated and analyzed the relationship between medical resources and economic conditions of OECD member countries and extracted factors for introducing imaging diagnostic equipment in each country. We also investigated the possibility of introducing diagnostic imaging equipment. Methods: A principal component analysis was conducted from medical environment indices and economic situation indices; the results were visualized on a graph with the extracted two principal components as axes, and the target nations were categorized according to the possibility of introducing diagnostic imaging equipment. Next, with the number of CTs and MRIs as response variables, we visualized the probability results on a graph by conducting a multiple regression analysis with the indices as explanatory variables and extracting the most influential factors on the number of diagnostic imaging equipment introduced. Results: We classified 29 countries into four groups according to medical environment and economic situation indices. By extracting from the four groups a group with a high possibility for introducing medical equipment then conducting a multiple regression analysis with CT and MRI unit counts as objective variables and other medical environment and economic situation indices as explanatory variables, it became clear that the factor with the greatest influence on CT and MRI unit counts is the number of hospital beds. Conclusion: As topics of future studies, we would like to clarify the factors behind as well as the probability for the introduction of medical equipment in each nation by researching high-growth medical equipment markets. (C) 2018 Fellowship of Postgraduate Medicine. Published by Elsevier Ltd. All rights reserved