114 research outputs found
A Rare Cause of Neck Mass: Pilomatrixoma
Pilomatrixoma (pilomatricoma) (Malherbe’s calcifying epithelioma), although rare, is the second most frequent benign skin tumour in childhood. It originates from the hair follicles. It is most commonly seen on the head and in the neck region, it also may be located on the upper extremities. Diagnosis may be confused with other skin tumours and malignancies. In this case, we report on a patient who presented with a mass on the neck diagnosed as a pilomatrixoma
Container vessel stowage plan using genetic, hill-climbing and simulated annealing algorithms
Container vessel stowage is vital for reducing extra cost and the vessel’s turn-around time in ports. Several studies have been conducted to be able to solve this problem. However, this problem has not been dealt with completely due to container stowage problem is complex problem which is literally considered as a NP-hard problem. Hence, the principal objective of this study is to find optimal container stowage plan for container vessel calling at multiple ports. Algorithms are the most widely-used methods for finding optimal solution in container vessel stowage problem. In this study, Genetic, Hill-Climbing and Simulated Annealing algorithm are implemented considering same size and two different types of containers (refrigerated and standard containers). After finding the numerical test results from these three algorithms, the effectiveness of the algorithms for the problem are evaluated
Alüminyum hidroksit ve magnezyum hidroksit katkısının termoplastik poliüretan malzemelerin mekanik özelliklerine etkisi
Thermoplastic polyurethane materials are widely used in automotive, clothing, electrical and electronics, medical, construction, machine industry due to excellent physical and chemical properties. Thermoplastic polyurethane materials combustion and resistance to high temperature characteristics are poor. Additives and fillers are added into the polyurethane matrix to improve those properties. Particularly adding these agents as a flame retardant are affect mechanical properties of polyurethane materials. Therefore, it is important to determinate the mechanical properties of these materials. In this study, 5% by weight of the thermoplastic polyurethane material, aluminium tri hydroxide (ATH, (Al2O3 3H(2)O)) and magnesium hydroxide (MgOH, (Mg(OH)(2))) were added. Ammonium polyphosphate (APP) as an intumescent flame retardant with inorganic flame retardants were added to increase the flame resistance of produced composite structure. Tensile test, tear test, hardness and Izod impact tests were made and compared of those produced composites. As a result of experiments the addition of ATH has lowered the tensile strength and tear strength contrast to this the addition of MgOH has improved those properties. Hardness and Izod impact test results were showed that both of the additives have no negative effect
A Rare Cause of Acute Abdominal Pain in Childhood: Peptic Ulcer Perforation
Four children with a mean age of 12 years were referred to our emergency department with a history of abdominal pain. Examination revealed tenderness in the lower abdomen, in particular the left iliac fossa. The youngest child, who was 3 years old, also presented with shock. Abdominal X-rays revealed free air under both hemidiaphragms. Subsequent surgery was administered as the primary treatment of three patients and a partial resection was performed in the remaining one. The youngest child died and the others were discharged. These cases emphasize that although uncommon, alternate diagnoses must be kept in mind in children presenting with lower abdominal pain
The Comparison of Reported Ingested Paracetamol Dose with Serum Blood Concentrations and Their Relationship with N-Acetylcysteine Administration: A Retrospective Study of 117 Patients
Introduction:We aimed to compare the patient reported ingested and blood paracetamol concentrations (BPC) and to investigate the indications for N-acetylcysteine (NAC) administration in referred patients.Methods:This is a retrospective study of acute paracetamol intoxications (API) at the tertiary paediatric emergency department (ED) between June 2015-June 2019. We evaluated the demographics, cause of intoxications, reported doses (mg/kg), BPCs (8/4/12/16 and/or 24th hours). Indications of antidote usage and referral to ED were accepted as BPC >150 mg/kg.Results:Overall, we reviewed 117 cases of acute API. The mean age was 8.97 (±6.0) years, and 68.3% were female. The reported ingested of paracetamol (RIP) median dose was 2725 mg (mean 138±51.9 mg/kg). Adolescents had a significantly higher RIP than that of younger subjects (p150 mg/kg, physicians at the first healthcare facility tended to administer activated charcoal (90.9%), gastric lavage (68%) and intravenous NAC (48%). The referring healthcare facility physicians-initiated NAC particularly for patients who reported ingesting >150 mg/kg (p=0.001).Conclusion:RIP doses should not be used to determine the need for NAC. The antidote should be used in centres where BPCs are not available or in a group of patients who cannot be transferred to a referral centre within the first eight hours
A novel survival algorithm in COVID-19 intensive care patients: the classification and regression tree (CRT) method
Background/aim: The present study aimed to create a decision tree for
the identification of clinical, laboratory and radiological data of
individuals with COVID-19 diagnosis or suspicion of Covid-19 in the
Intensive Care Units of a Training and Research Hospital of the
Ministry of Health on the European side of the city of Istanbul.
Materials and methods: The present study, which had a retrospective and
sectional design, covered all the 97 patients treated with Covid-19
diagnosis or suspicion of COVID-19 in the intensive care unit between
12 March and 30 April 2020. In all cases who had symptoms admitted to
the COVID-19 clinic, nasal swab samples were taken and thoracic CT was
performed when considered necessary by the physician, radiological
findings were interpreted, clinical and laboratory data were included
to create the decision tree. Results: A total of 61 (21 women, 40 men)
of the cases included in the study died, and 36 were discharged with a
cure from the intensive care process. By using the decision tree
algorithm created in this study, dead cases will be predicted at a rate
of 95%, and those who survive will be predicted at a rate of 81%. The
overall accuracy rate of the model was found at 90%. Conclusions: There
were no differences in terms of gender between dead and live patients.
Those who died were older, had lower MON, MPV, and had higher D-Dimer
values than those who survived
Analysis of the integrated intensity of the central peaks calculated as a function of temperature in the ferroelectric phase of lithium tantalate
The integrated intensity of the central peak is calculated as a function of temperature in the ferroelectric phase (T < TC) of nearly stoichiometric LiTaO3. This calculation is performed using the temperature dependence of the order parameter obtained from the mean field theory at temperatures lower than the transition temperature TC (TC = 963 K) of this crystal. The calculated values of the order parameter (squared) are fitted to the integrated intensity of the central peaks as observed from the Raman and Brillouin scattering experiments as reported in the literature in the ferroelectric phase of nearly stoichiometric LiTaO3. Our results are in good agreement with the observed behavior of LiTaO3 crystal. Because of the applications of LiTaO3 in several academic disciplines including the material science and thermal science, it is beneficial to investigate dynamic properties of this crystal such as the damping constant, inverse relaxation time and the activation energy as also we studied here
Calculation of the DampingConstant, Relaxation Timeand the Activation Energy ofRaman Modes inStoichiometric LiTaO3
Order-disorder transition in the ferroelectric LiTaO3
The temperature dependences of the damping constant and the relaxation time are calculated by using the Raman frequencies of a* and the lowest A(1) (TO) phonons in the ferroelectric phase close to the ferroelectric-paraelectric transition in LiTaO3 (T-C = 963 K). Both calculations are performed by considering the frequency as an order parameter for the pseudospin-phonon (PS) and the energy fluctuation (EF) models using the observed data from the literature. Values of the activation energies of this crystal are also deduced by using both models in this crystal. Our results show that the PS and EF models can describe the observed behavior adequately for the order-disorder transition in LiTaO3
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