Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome, cardiogenic shock, and sudden cardiac death in women of reproductive age who have no traditional risk factors for coronary artery disease. The etiology, prognosis, and treatment of SCAD remain poorly defined. Coronary angiography is the gold standard for diagnosis. Management includes medical therapy and revascularization procedures using percutaneous intervention and coronary artery bypass grafting. Possible mechanisms of SCAD include rupture of atherosclerotic plaque or vasa vasorum, hemorrhage between the outer media and external lamina with intramedial hematoma expansion, and compression of the vessel lumen. We report a case of SCAD in a 39-year-old woman presenting with ST-elevation myocardial infarction midway through her menstrual cycle. Her medications included fenfluramine for obesity and hydrochlorothiazide, amlodipine, and atenolol for hypertension.

Research on analogical problem solving has delineated several factors that impact one's ability to spontaneously generate a correct solution strategy to a target problem. These factors include, but are not limited to, type of analogy provided to subjects (i.e., partial versus complete), the level of analogical problem-solving expertise, and the absence of or type of analogical problem-solving training (i.e., teacher-generated or learner-generated) provided to learners. Recently, researchers have begun to focus on providing solvers with multiple practice opportunities and extending these opportunities over a systematically distributed period of time. When combined with analogical problem-solving training, these factors will augment the learner's ability to spontaneously generate a correct solution strategy to both complete and partial target problems. Using an experimental design, the present study examined the differential effects of type of analogue (partial versus complete), type of training (teacher-generated, learner-generated, or no training), and length of training (condensed versus extended) on novice learners' ability to spontaneously generate correct solution strategies to two target problems. Findings indicate that, on the complete target problem, regardless of training group membership, no effect over control group participants was found. Partial target problem results indicate a slight advantage for participating in the learner-generated extended training group over no training. Also on the partial target problem, a moderate advantage was found for participating in the learner-generated extended training group over the condensed training. Limitations of the study, implications for educators, and recommendations for future studies are provided.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第17946号 / 医博第3830号 / 新制||医||1000(附属図書館) / 30776 / 京都大学大学院医学研究科医学専攻 / (主査)教授 稲垣 暢也, 教授 小西 郁生, 教授 安達 泰治 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

This literature review explored health care system experiences of women who miscarried. Particular attention was placed on the women's psychological well-being including coping and, grief needs along with cultural concerns. The findings indicated a need for future qualitative research to be conducted in order to examine the lived experience of women who miscarry. With new advanced home diagnostic technologies allowing women to confirm pregnancy before their first missed menstrual period, future research must place focus on early pregnancy loss occurring before the 12th week of gestation. With pregnancies capable of being identified prior to establishment of formal prenatal care, there is a need to provide better support and counseling services in the ambulatory setting. Additionally, in an effort to optimize pregnancy outcomes, perinatal care guidelines must include preconception counseling for all women of childbearing age. Lastly, the phenomenon of miscarriage requires further examination from the male partner's perspective in order to improve overall nursing care within an event that affects a family.

Spontaneous mutagenesis can be divided into three main steps: the introduction of DNA damage and lesions, damage recognition and DNA repair. All sources of spontaneous mutagenesis originate from within the cell itself, e.g., polymerase errors cause DNA mismatches and reactive oxygen species alter the chemical composition of DNA bases. The combined effects of all these processes influence spontaneous genomic mutation rates, which are thought to be a characteristic of individual species and/or groups of species. Although much is known about different mutagens and how they cause mutations the sequence context of these mutations are less well understood. The results of this MSc study on mutation in the filamentous fungus Fusarium circinatum showed that the 5ʹ and 3ʹ neighbouring bases of a single nucleotide polymorphism can significantly influence the type of substitution that occurred leading to the formation of mutational motifs. This was the case for both sets of genes examined (core housekeeping and non-ribosomal protein synthetase genes), whose evolution is known to differ. The fact that none of the identified motifs are shared between the two sets of genes could indicate that the cellular mutagens and/or repair machinery function differently for the two gene groups. Furthermore, none of the mutable motifs that have been identified for the well-known mutagens in model organisms could be detected in the fungus, which suggests that mutagens and/or DNA repair mechanisms of this fungus are unique. Although limited information is available for non-model eukaryotes, an estimate for the rate at which mutations arise across the genome of F. circinatum could be a good starting point for comparisons of its evolutionary rate to those of its close relatives. This was accomplished using a fluctuation analysis involving nitrate non-utilizing mutation reversion. Although mutation rate determined in this study is probably not precisely accurate, it represents a good starting point for future comparative studies on the evolutionary rate of Fusarium species. As a whole this study laid the foundation for a better understanding of spontaneous mutagenesis at specific sites in certain groups of genes as well as across the genome of the economically important plant pathogen F. circinatum. Restricted until August 2017 / Dissertation (MSc)--University of Pretoria, 2013. / gm2013 / Microbiology and Plant Pathology / Unrestricted

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Figueroa-Ramosa et al. (2013) concluded that the combination of sedation withdrawal and mechanical ventilation withdrawal trial was feasible and well tolerated. The conclusion is not well supported because of the absence of a comparison to the uncombined protocol and due to evidence that the patients did not tolerate them particularly well.

Boerhaave syndrome is a spontaneous rupture of the esophagus. It results from a sudden increase in esophageal pressure combined with negative intrathoracic pressure as seen with severe straining or vomiting. Esophageal perforation is extremely rare with an incidence of approximately 3.1 per 1,000,000 per year with a mortality rate estimated to be 20-50%. The rare occurrence and fatal nature of an esophageal perforation makes this syndrome a difficult yet important diagnosis to consider in the clinical setting. This case presents a previously healthy 47-year-old gentleman who presented to a local emergency department with syncope, vomiting, and chest pain sequentially. He reported a 24-hour history of dark stools followed by syncope, and when he regained consciousness he had three bouts of retching and expulsion of coffee-ground vomitus. Shortly after emesis, the patient developed severe and continuous pain located in his central chest that radiated to his back. Upon arrival to the hospital he was tachycardic. Blood tests revealed metabolic acidosis, increased white blood cell count, elevated lactate, and significant anemia. The patient’s hemoglobin was 7.7 gm/dL, a significant drop from the patient’s baseline level of 14. The patient received 1 unit of packed red blood cells and was sent for imaging studies. Chest X-ray and CT imaging revealed free air in the mediastinum, and a subsequent Gastrografin esophagogram study revealed a lower esophageal perforation proximal to gastroesophageal junction. The patient was rushed to the operating room for emergency surgery. An esophagogastroduodenoscopy showed no active bleeds and confirmed a distal mucosal defect suggestive of perforation. The surgery team then performed a left thoracotomy with intercostal muscle harvest and esophageal repair, with the patient needing an additional 4 units of packed red blood cells during surgery. He tolerated the surgery well and received appropriate post-op care in the ICU. A repeat Gastrografin and barium swallow esophagogram revealed no evidence of leak, strictures, or complications from the operation. A follow up CT image of the chest, abdomen, and pelvis was performed one month after hospital discharge, and results showed complete resolution of mediastinal air without evidence of esophageal leak. This case demonstrates how a spontaneous esophageal perforation can occur in previously healthy, middle aged patients with no significant GI history or identifiable risk factors. Given this information, clinicians should consider Boerhaave Syndrome when a patient of any age presents with chest pain after an episode of emesis.

Landfill fires are relatively common incidents that landfill operators encounter which have great impact on landfill structure and the environment. According to a U.S. Fire Administration report in 2001, an average of 8,300 landfill fires occurs each year in the United States, most of them in the spring and summer months. Subsurface spontaneous fires are considered the most dangerous and difficult to detect and extinguish among landfill fires. Few studies have been conducted on spontaneous fires in landfills. Information regarding the thermal behavior of solid waste is not available nor have measurements been made to evaluate spontaneous ignition of solid waste. The purpose of this research was to provide information concerning the initiation of spontaneous ignition incidents in landfills, and investigate the conditions favoring their occurrence. This study enabled better understanding of the self-heating process and spontaneous combustion in landfills. Effects of parameters critical to landfill operation on spontaneous combustion were determined. Spontaneous combustion occurs when materials are heated beyond the ignition temperature. Temperature rise occurs inside the landfill due to exothermic reactions which cause self-heating of the solid waste. Oxygen introduction leading to biological waste degradation and chemical oxidation is believed to be the main cause of rising solid waste temperatures to the point of ignition. A survey was distributed to landfill operators collecting information regarding spontaneous firs incidents in their landfills. Survey results raised new questions necessitating further study of subsurface fires incidents. Subsurface spontaneous fires were not restricted to any landfill geometry or type of waste (municipal, industrial, commercial, and construction and demolition). Results showed that landfill fires occur in landfills that do and do not recirculate leachate. Although new methods have been developed to detect subsurface fires, landfill operators depend primarily on visual observation of smoke or steam to detect the subsurface fires. Also, survey results indicated that excavating and covering with soil are the most widespread methods for extinguishing subsurface fires. Methane often has been suspected for initiating spontaneous subsurface firs in the landfill. However, combustible mixture of methane and oxygen requires very high temperature to ignite. In this study it was shown that spontaneous fires are initiated by solid materials with lower ignition points. Laboratory tests were conducted evaluating the effect of moisture content, oxygen concentration and leachate on spontaneous ignition of solid waste. A new procedure for testing spontaneous ignition is described based on the crossing-point method. The procedure was used to study the spontaneous combustion of solid waste and determine the auto-ignition temperature of the solid waste components and a synthesized solid waste. Correlations have been established between auto-ignition temperature, specific weight and energy content and between self-heating temperature and specific weight. Correlations indicated that compaction can help avoid spontaneous combustion in the landfill. Dense materials require higher energy to increase in temperature and limit the accessibility of oxygen. In the experimental work, moisture was found to promote both biological and chemical self-heating. Increasing moisture content lowers the solid waste permeability and absorbs more energy as it evaporates. Dissolved solids in leachate were found to promote self-heating and ignition more than distilled water. Varying oxygen concentrations indicated that heat generation occurs due to chemical oxidation even at oxygen concentration as low as 10% by volume. However, at 10% by volume oxygen, solid waste did not exhibit thermal runaway nor flammable combustion. At 0% by volume oxygen, tests results indicated occurrence of self-heating due to slow pyrolysis. A numerical one-dimensional energy model was created to simulate temperature rise in landfill for four different scenarios. Using the results from the laboratory experiment, the model estimated the heat generation in solid waste due to chemical reactions. Results from the scenario simulations indicated that moisture evaporation is the major heat sink in the landfill. The model showed that gas flow has a cooling effect due to increasing amount of evaporated water and can control the temperature inside the landfill. The model showed that a temperature higher than the biological limit can be maintained in the landfill without initiating spontaneous fire.

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