Reduction of Large Detailed Chemical Kinetic Mechanisms for Autoignition Using Joint Analyses of Reaction Rates and Sensitivities

A new technique of reduction of detailed mechanisms for autoignition, which is based on two analysis methods is described. An analysis of reaction rates is coupled to an analysis of reaction sensitivity for the detection of redundant reactions. Thresholds associated with the two analyses have a great influence on the size and efficiency of the reduced mechanism. Rules of selection of the thresholds are defined. The reduction technique has been successfully applied to detailed autoignition mechanisms of two reference hydrocarbons: n-heptane and iso-octane. The efficiency of the technique and the ability of the reduced mechanisms to reproduce well the results generated by the full mechanism are discussed. A speedup of calculations by a factor of 5.9 for n-heptane mechanism and by a factor of 16.7 for iso-octane mechanism is obtained without losing accuracy of the prediction of autoignition delay times and concentrations of intermediate species

Relationship of creative projects in anatomy to medical student professionalism, test performance and stress: an exploratory study

<p>Abstract</p> <p>Background</p> <p>The anatomy course offers important opportunities to develop professionalism at an early stage in medical education. It is an academically significant course that also engenders stress in some students.</p> <p>Methods</p> <p>Over a three-year period, 115 of 297 students completed creative projects. Thirty-four project completers and 47 non-completers consented to participate in the study. Projects were analyzed for professionalism themes using grounded theory. A subset of project completers and non-completers were interviewed to determine their views about the stress of anatomy and medical school, as well as the value of the creative projects. We also compared test performance of project completers and non-completers.</p> <p>Results</p> <p>Projects completed early in the course often expressed ambivalence about anatomy, whereas later projects showed more gratitude and sense of awe. Project completers tended to report greater stress than noncompleters, but stated that doing projects reduced stress and caused them to develop a richer appreciation for anatomy and medicine. Project completers performed significantly lower than non-completers on the first written exam (pre-project). Differences between groups on individual exams after both the first and second creative project were nonsignificant.</p> <p>Conclusion</p> <p>For some students, creative projects may offer a useful way of reflecting on various aspects of professionalism while helping them to manage stress.</p

Aorto-ventricular tunnel

Aorto-ventricular tunnel is a congenital, extracardiac channel which connects the ascending aorta above the sinutubular junction to the cavity of the left, or (less commonly) right ventricle. The exact incidence is unknown, estimates ranging from 0.5% of fetal cardiac malformations to less than 0.1% of congenitally malformed hearts in clinico-pathological series. Approximately 130 cases have been reported in the literature, about twice as many cases in males as in females. Associated defects, usually involving the proximal coronary arteries, or the aortic or pulmonary valves, are present in nearly half the cases. Occasional patients present with an asymptomatic heart murmur and cardiac enlargement, but most suffer heart failure in the first year of life. The etiology of aorto-ventricular tunnel is uncertain. It appears to result from a combination of maldevelopment of the cushions which give rise to the pulmonary and aortic roots, and abnormal separation of these structures. Echocardiography is the diagnostic investigation of choice. Antenatal diagnosis by fetal echocardiography is reliable after 18 weeks gestation. Aorto-ventricular tunnel must be distinguished from other lesions which cause rapid run-off of blood from the aorta and produce cardiac failure. Optimal management of symptomatic aorto-ventricular tunnel consists of diagnosis by echocardiography, complimented with cardiac catheterization as needed to elucidate coronary arterial origins or associated defects, and prompt surgical repair. Observation of the exceedingly rare, asymptomatic patient with a small tunnel may be justified by occasional spontaneous closure. All patients require life-long follow-up for recurrence of the tunnel, aortic valve incompetence, left ventricular function, and aneurysmal enlargement of the ascending aorta

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

SOCİAL AND CULTURAL LİFE IN ANATOLİAN PRİNCİPALİTİES IN THE PERSPECT OF VAKFİYES

Anadolu Beylikleri dönemi, Türk tarihinin, kısa sayılabilecek fakat etkilerinden dolayı büyük önemi olan bir dönemidir. Bu dönem, Türk Tarihi içerisinde, kendinden önceki Türk Devletleri'nin bir devamı ve kendinden sonrakilere bir örnektir. Bu Beylikler arasından çıkan Osmanlılar, zamanla, her yönüyle büyük bir imparatorluk haline gelmiştir. Beylikler döneminin daha iyi aydınlatılmasında resmi belgeler olan vakfiyeler, yararlanılabilecek tarihi kaynaklardandır. İncelediğimiz vakfiyelerde, Anadolu Beylikleri dönemine ait sosyal, kültürel, ekonomik, siyasi ve dini bilgiler bulunmaktadır. İncelediğimiz vakfiyelerdeki bilgiler, Türk Kültürünün Anadolu Beylikleri'nden günümüze kadar, gelişerek, devam ettiğini göstermektedir. Vakfiye çalışmalarının artmasıyla, tarihimizdeki birçok mesele aydınlığa kavuşacaktır.The period of Anatolian Principalities is not only a short period but it is also a great time for the it's effectiveness of the time.This period is a great example of for it's former Turkish states and the followings.The Ottoman Empire came out from this pirincipalities and it became a great empire from many aspects. The vakfiyes are historic and formal documents to enlighten the periods of Principalities. When we survey the vakfiyes, they contain the information of social, cultural, economic, politics and religious that belong to the period of Anatolian Principalities. The information in vakfiyes shows us that the Turkish culture is devoloping itself from the past to the present. With the increase of workings in vakfiyes, many problems in our history are going to be solved

Migration Of A Bullet From The Inferior Vena Cava To The Right Pulmonary Artery: Case Report

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