Chemical diffusion of fluorine in melts in the system Na2OAl2O3SiO2

The volatilization of fluorine from three melts in the system Na2OAl2O3SiO2 has been investigated at 1 atm pressure and 1200–1400°C. The melts chosen have base compositions corresponding to albite, jadeite and a peraluminous melt with 75 mole % SiO2. Melt spheres were suspended from platinum loops in a vertical tube furnace in a flow of oxygen gas, then quenched, sectioned and analysed by electron microprobe. The microprobe scans indicate that transport of fluorine to the melt-vapor interface is by binary, concentration-independent interdiffusion of fluorine and oxygen. FO interdiffusivity increases in the order albite < peraluminous < jadeite. There is no simple reciprocal relationship between FO interdiffusivity and melt viscosity. Comparison with data on high-pressure interdiffusivity of fluorine and oxygen in jadeite melt indicates that FO interdiffusivity increases with pressure from 0.001 to 10 kbar while the activation energy remains unchanged. Fluorine chemical diffusivity in albite melt is substantially lower than H2O chemical diffusivity in obsidian melts suggesting that different diffusive mechanisms are responsible for the transport of F and H2O in igneous melts. Fluorine diffuses in albite melt via an anionic exchange with oxygen whereas water probably diffuses in obsidian melt via an alkali exchange mechanism

ASSESSMENT OF TWO PHASE FLOW IN A VENTURE CONVERGENT- DIVERGENT NOZZLE.

The present study emphasized on the information of cavitations during the dual phase flow i.e. (water and vapor) in venture  converge-diverge nozzle. The choice of nozzle with a transparent material (PMMA), was found suitable for the observation and measurements. The model of this problem of defining dual compressible viscous flow, and k-epsilon model. The comparisons of numerical calculation and experimental observation were found to be comparatively coincidable in cavitational zone and throat pressure, and fractional phase flow.</p

Herpes Zoster after COVID-vaccination

COVID-19 presents in various ways, but mainly as a pulmonary disease (Marzano, 2020). Skin manifestations have been reported, including reactivation of the varicella-zoster virus (Marzano, 2020). Our case report describes two adults developing herpes zoster after vaccination with tozinameran (the Pfizer-BioNTech COVID-19 mRNA vaccine). A possible cause for this reaction is a transient lymphocytopenia that occurs after the vaccination — similar to that in COVID-19 disease (Mulligan, 2020; Wang, 2020; Qin, 2020; Brabilla, 2020; Wang, 2020; Wei, 2017). In the context of vaccinating older and/or immunocompromised adults, our observations can be the starting point for further evaluation of a possible relationship between COVID-19, COVID vaccines, and herpes zoster

Risk factors for medication errors at admission in preoperatively screened patients

Personalised Therapeutic

Therapeutic reasoning: from hiatus to hypothetical model

Rationale Extensive research has been conducted on clinical reasoning to gain better understanding of this process. Clinical reasoning has been defined as the process of thinking critically about the diagnosis and patient management. However, most research has focused on the process of diagnostic reasoning. Because of the lack of understanding regarding therapeutic reasoning, education in patient management decisions lacks a solid theoretical basis. Aims and objective To improve medical education, training and refresher courses with regard to therapeutic decision making. Methods A search on the literature about clinical reasoning has been conducted. Based on this literature a hypothetical model of therapeutic reasoning is developed. Results It is assumed on the literature about diagnostic and therapeutic reasoning that after the diagnosis has been formulated, the process of determining the therapy is initiated by a concept called the therapy script. Patient cases unconsciously elicit such scripts and they consist of relevant treatments, knowledge and clinical experiences. Analytical and non-analytical processes determine the final choice of therapy. Subsequently, these processes adapt the therapy script continuously. Conclusions A hypothetical model of therapeutic reasoning has been developed in order to improve medical education, training and refresher courses with regard to therapeutic decision making. Future research should empirically test the validity of this hypothetical model in different phases of the medical education continuu

Internal Hernia After Laparoscopic Antecolic Roux-en-Y Gastric Bypass

BACKGROUND: We evaluated the incidence and presentations of internal hernias (IH) after laparoscopic antecolic Roux-en-Y gastric bypass (RYGB) at our institution. METHODS: We retrospectively reviewed the records of 594 patients who underwent laparoscopic antecolic RYGB at our institution between December 2004 and December 2010. RESULTS: Five hundred ninety-four patients underwent laparoscopic antecolic RYGB with a mean follow-up of 50.5 months. Thirty-six patients developed 37 IH (6.2 %) requiring surgical intervention. Mean age of IH patients was 36.9 years. Thirty-one out of 36 were female. Mean preoperative BMI was 44.3 Kg/m(2). The mean time of presentation after their RYGB was 25.9 months. The mean % excess body weight loss at time of presentation was 54.0 %. Twenty-five out of 37 of IH occurred at Petersen\u27s space; 9/37 IH occurred under the jejunojejunostomy; three patients had hernias at both locations. Mesenteric swirling was the most common CT scan finding in 20/36 (55.6 %). Six out of 36 CT were initially read as normal; however, on retrospective review by a radiologist, abnormalities indicating IH were found in 4/6. Patients presented with different degrees of acuity: 6/37 with chronic abdominal pain and 28/37 with acute abdominal pain. Bowel necrosis was found in 3/37. CONCLUSION: IH is a serious and potentially fatal complication of RYGB. Presentation can vary from chronic abdominal pain to bowel necrosis. CT is helpful in providing diagnosis; however, careful attention to the specific signs of small bowel volvulus, such as mesenteric swirl sign, should be given. IH should be considered in RYGB patients who present with even vague symptoms

Association of a Multifaceted Intervention With Ordering of Unnecessary Laboratory Tests Among Caregivers in Internal Medicine Departments

Importance: Inappropriate use of laboratory testing is a challenging problem. Estimated overuse rates of approximately 20% have been reported. Effective, sustainable solutions to stimulate optimal use are needed. Objective: To determine the association of a multifaceted intervention with laboratory test volume. Design, Setting, and Participants: A before-after quality improvement study was performed between August 1, 2016, and April 30, 2018, in the internal medicine departments of 4 teaching hospitals in the Netherlands. Data on laboratory order volumes from 19 comparable hospitals were used as controls. The participants were clinicians ordering laboratory tests. Interventions: The intervention included creating awareness through education and feedback, intensified supervision of residents, and changes in order entry systems. Interventions were performed by local project teams and guided by a central project team during a 6-month period. Sustainability was investigated during an 8-month follow-up period. Main Outcomes and Measures: The primary outcome was the change in slope for laboratory test volume. Secondary outcomes were change in slope for laboratory expenditure, order volumes and expenditure for other diagnostic procedures, and clinical outcomes. Data were collected on duration of hospital stay, rate of repeated outpatient visits, 30-day readmission rate, and rate of unexpected prolonged duration of hospital stay for patients admitted for pneumonia. Results: The numbers of internists and residents ordering tests in hospitals 1 to 4 were 16 and 30, 18 and 20, 13 and 17, and 21 and 60, respectively. Statistically significant changes in slope for laboratory test volume per patient contact were found at hospital 1 (change in slope, -1.55; 95% CI, -1.98 to -1.11; P <.001), hospital 3 (change in slope, -0.74; 95% CI, -1.42 to -0.07; P =.03), and hospital 4 (change in slope, -2.18; 95% CI, -3.27 to -1.08; P <.001). At hospital 2, the change in slope was not statistically significant (-0.34; 95% CI, -2.27 to 1.58; P =.73). Laboratory test volume per patient contact decreased by 11.4%, whereas the volume increased by 2.4% in 19 comparable hospitals. Statistically significant changes in slopes for laboratory costs and volumes and costs for other diagnostic procedures were also observed. Clinical outcomes were not associated with negative changes. Important facilitators were education, continuous attention for overuse, feedback, and residents' involvement. Important barriers were difficulties in data retrieval, difficulty in incorporation of principles in daily practice, and high resident turnover. Conclusions and relevance: A set of interventions aimed at changing caregivers' mindset was associated with a reduction in the laboratory test volume in all departments, whereas the volume increased in comparable hospitals in the Netherlands. This study provides a framework for nationwide implementation of interventions to reduce unnecessary laboratory testing