37 research outputs found

    Importance of realistic phase space representations of initial quantum fluctuations using the stochastic mean-field approach for fermions

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    In the stochastic mean-field (SMF) approach, an ensemble of initial values for a selected set of one-body observables is formed by stochastic sampling from a phase-space distribution that reproduces the initial quantum fluctuations. Independent mean-field evolutions are performed with each set of initial values followed by averaging over the resulting ensemble. This approach has been recently shown to be rather versatile and accurate in describing the correlated dynamics beyond the independent particle picture. In the original formulation of SMF, it was proposed to use a Gaussian assumption for the phase-space distribution. This assumption turns out to be rather effective when the dynamics of an initially uncorrelated state is considered, which was the case in all applications of this approach up to now. Using the Lipkin-Meshkov-Glick (LMG) model, we show that such an assumption might not be adequate if the quantum system under interest is initially correlated and presents configuration mixing between several Slater determinants. In this case, a more realistic description of the initial phase-space is necessary. We show that the SMF approach can be advantageously combined with standard methods to describe phase-space in quantum mechanics. As an illustration, the Husimi distribution function is used here to obtain a realistic representation of the phase-space of a quantum many-body system. This method greatly improves the description of initially correlated fermionic many-body states. In the LMG model, while the Gaussian approximation failed to describe these systems in all interaction strength range, the novel approach gives a perfect agreement with the exact evolution in the weak coupling regime and significantly improves the description of correlated systems in the strong coupling regime.Comment: 12 pages, 10 figure

    The importance of carotid artery stiffness and increased intima-media thickness in obese children

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    Background. Atherosclerosis that starts in childhood invariably advances during adulthood. Aim. We aimed to study the effect of obesity on main carotid artery intima-media thickness and arterial stiffness. Material and methods. A total of 78 children were studied from October 2010 to February 2011. They were divided into obese (42 – group 1) and normal (36 – group 2). All the children were subjected to physical examination, routine biochemical and haematological analysis, carotid ultrasonography and echocardiographic measurements. A detailed medical history was obtained. Body mass index (BMI) was calculated by dividing participants’ weight in kilograms by the square of their height in metres. Stiffness index β was calculated using blood pressure and diameter of the systolic and diastolic artery. Intima-media thickness was also measured. Results. The mean age of the obese and normal (control) groups were 10.12±2.12 years and 9.78±1.78 years respectively. Weight, BMI, and systolic and and diastolic blood pressure values were significantly higher in the obese group (all

    Evaluation of nutritional status in pediatric intensive care unit patients: the results of a multicenter, prospective study in Turkey

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    IntroductionMalnutrition is defined as a pathological condition arising from deficient or imbalanced intake of nutritional elements. Factors such as increasing metabolic demands during the disease course in the hospitalized patients and inadequate calorie intake increase the risk of malnutrition. The aim of the present study is to evaluate nutritional status of patients admitted to pediatric intensive care units (PICU) in Turkey, examine the effect of nutrition on the treatment process and draw attention to the need for regulating nutritional support of patients while continuing existing therapies.Material and MethodIn this prospective multicenter study, the data was collected over a period of one month from PICUs participating in the PICU Nutrition Study Group in Turkey. Anthropometric data of the patients, calorie intake, 90-day mortality, need for mechanical ventilation, length of hospital stay and length of stay in intensive care unit were recorded and the relationship between these parameters was examined.ResultsOf the 614 patients included in the study, malnutrition was detected in 45.4% of the patients. Enteral feeding was initiated in 40.6% (n = 249) of the patients at day one upon admission to the intensive care unit. In the first 48 h, 86.82% (n = 533) of the patients achieved the target calorie intake, and 81.65% (n = 307) of the 376 patients remaining in the intensive care unit achieved the target calorie intake at the end of one week. The risk of mortality decreased with increasing upper mid-arm circumference and triceps skin fold thickness Z-score (OR = 0.871/0.894; p = 0.027/0.024). The risk of mortality was 2.723 times higher in patients who did not achieve the target calorie intake at first 48 h (p = 0.006) and the risk was 3.829 times higher in patients who did not achieve the target calorie intake at the end of one week (p = 0.001). The risk of mortality decreased with increasing triceps skin fold thickness Z-score (OR = 0.894; p = 0.024).ConclusionTimely and appropriate nutritional support in critically ill patients favorably affects the clinical course. The results of the present study suggest that mortality rate is higher in patients who fail to achieve the target calorie intake at first 48 h and day seven of admission to the intensive care unit. The risk of mortality decreases with increasing triceps skin fold thickness Z-score

    A Rare Presentation of Familial Mediterranean fever; Acute Scrotum and Hydrocele Amyloidosis

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    Background: Familial Mediterranean Fever (FMF) is a genetic disease characterized by recurrent febrile attacks and inflammation of serous membranes. Amyloidosis is frequent in untreated FMF patients and is also the most important complication of FMF. It is generally seen with renal, hepatic, gastrointestinal, spleen, testicular and thyroidal involvement. Case Presentation: Herein, we report a case with acute scrotum and hydrocele amyloidosis as a presenting finding in a child with FMF. Conclusion: Although the acute scrotum and scrotal swelling are not characteristic clinical features of FMF, this genetic disease should not be forgotten in the differential diagnosis of acute scrotum in patients of Mediterranean origins

    Coexistence of Familial Mediterranean Fever and Hyperimmunoglobulinemia D Syndrome in a Child

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    Hereditary periodic fever syndromes are Mendelian inherited single gene diseases which are also known as hereditary autoinflammatory syndromes, are characterized by recurrent attacks of fever and inflammation. Familial Mediterranean Fever and Hyperimmunoglobulinemia D syndrome are prototypes and are inherited autosomal recessively. The diagnosis is based on clinical course, family history and is confirmed with genetic mutation analysis. We describe a 5-year-old boy who had recurrent attacks of fever, skin rash, and cervical lymphadenopathy since he was 2 years old. His genetic analysis revealed homozygous M694V and V377I for MEFV and MVK gene respectively. Due to our knowledge, this is the first report of a patient who has both HIDS and FMF clinical and genetic features

    How does parents' visual perception of their child's weight status affect their feeding style?

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    Conclusion: Various feeding styles were related to maternal visual perception. The best approach to preventing obesity and underweight may be to focus on achieving correct parental perception of the weight status of their children, thus improving parental skills and leading them to implement proper feeding styles

    Examining the perceived stress and body image in burn patients: A cross-sectional study

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    This study aimed to examine the perceived stress and body image in burn patients and the relationship between these two variables. This is a descriptive and cross-sectional study. The study included total of 144 patients who had burn injuries, received treatment in a research and training hospital and were scheduled to be discharged. The data were collected prospectively by the researchers, using descriptive methods, Kruskal Wallis test, paired samples t test, and Pearson's correlation analysis. Of the patients, 59% were between the ages of 18 and 35 years, 68.1% were male, 65.3% had second-degree burns, 77.1% had burn surfaces ranging between 10% and 20% of their body, and 54.9% had autograft surgery. The burn patients aged 51 years and over had higher perceived stress than younger patients, and the difference between them was statistically significant (P < 0.05). As the percentage of burn surface increased, the perceived stress increased, and the perceived body image weakened (P < 0.05). The burn patients with autograft surgery had lower perceived stress and higher perceived body image than those without autograft surgery, and the difference between them was statistically significant (P < 0.01). This study found an inverse relationship between perceived stress and body image in burn patients, which was affected by the percentage of burn surface and autograft surgery. Relevant interventions are suggested to increase perceived body image in burn patients and reduce their perceived stress. © 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd

    Mannose-binding lectin (MBL) levels in children with Hashimoto’s thyroiditis

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    OBJECTIVE: Hashimoto’s thyroiditis (HT) was described many years ago, but the etiopathogenesis remains unclear. Man-nose-binding lectin (MBL) initiates complement activation in the lectin pathway. We determined MBL levels in children with HT and the associations thereof with thyroid hormone and thyroid autoantibody levels. METHODS: Thirty-nine patients with HT and 41 controls were enrolled from the pediatric outpatient clinics. Subjects were grouped according to their thyroid functions: Euthyroid, marked hypothyroidism and clinical/subclinical hyperthyroidism. MBL levels were compared among these groups. Serum MBL levels of the subjects were determined using MBL Human ELISA kit. RESULTS: Serum MBL levels were studied in serum samples from the 80 subjects (48 (60.0%) females). MBL levels in HT and control groups were 50.787±34.718 and 50.593±44.28 ng/ml (p=0,983), respectively. In HT group, there was no significant difference in MBL levels between thyroid function groups (p=0.869). In addition, gender was not detected as a factor for serum MBL levels. Also we found negative correlation between WBC and serum MBL levels (r=-0.532; p=0.050). Otherwise there was no correlation between TSH, anti-TPO and anti-TG with serum MBL levels. CONCLUSION: MBL levels did not decrease in HT patients. Further research is needed to elucidate more fully any role for MBL in the development of autoimmune thyroid disease
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