361 research outputs found
Flexible profile approach to the conjugate heat transfer problem
The flexible profile approach proposed earlier to create CTM (compact or
reduced order thermal models) is extended to cover the area of conjugate heat
transfer. The flexible profile approach is a methodology that allows building a
highly boundary conditions independent CTM, with any desired degree of
accuracy, that may adequately replace detailed 3D models for the whole spectrum
of applications in which the modeled object may be used. The extension to
conjugate problems radically solves the problem of interfacing two different
domains. Each domain, fluid or solid, can be "compacted" independently creating
two CTM that can be joined together to produce reliable results for any
arbitrary set of external boundary conditions.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Nonlinear structures: explosive, soliton and shock in a quantum electron-positron-ion magnetoplasma
Theoretical and numerical studies are performed for the nonlinear structures
(explosive, solitons and shock) in quantum electron-positron-ion
magnetoplasmas. For this purpose, the reductive perturbation method is employed
to the quantum hydrodynamical equations and the Poisson equation, obtaining
extended quantum Zakharov-Kuznetsov equation. The latter has been solved using
the generalized expansion method to obtain a set of analytical solutions, which
reflect the possibility of the propagation of various nonlinear structures. The
relevance of the present investigation to the white dwarfs is highlighted.Comment: 7 figure
Homing and reparative effect of intra-articular injection of autologus mesenchymal stem cells in osteoarthritic animal model
<p>Abstract</p> <p>Background</p> <p>This work aimed to study the homing evidence and the reparative effect of mesenchymal stem cells (MSCs) in the healing process of induced osteoarthritis in experimental animal model (donkeys).</p> <p>Methods</p> <p>Twenty-seven donkeys were equally divided into 3 groups based on the observation period after induction of arthritis (3, 6 and 9 weeks) to achieve different degrees of osteoarthritis. Each group was subdivided into three subgroups of three animals each based on the follow-up period (1, 2 and 6 months) after treatment. The induction was done through intra-articular (IA) injection of 2 ml of Amphotericin-B in both carpal joints. MSCs were harvested in a separate procedure, labeled with green fluorescent protein (GFP) using monster GFP vector and suspended in hyaluronic acid for IA injection. Treatment approaches consisted of cell-treatment using MSCs suspended in 3 ml of hyaluronic acid (HA) for the right carpal joint; and using the same amount of (HA) but without MSCs for the left contralateral carpal joint to serve as a control. Animals were assessed clinically and radiologically before and after treatment. Synovial fluid was also evaluated. Histopathologically; articular cartilage structural changes, reduction of articular cartilage matrix staining, osteophyte formation, and subchondral bone plate thickening were graded. Data was summarized using median and percentile for scores of histopathologic grading. Comparison between groups was done using non-parametric Mann Whitney test.</p> <p>Results</p> <p>The reparative effect of MSCs was significant both clinically and radiologically in all treated groups (P < 0.05) compared to the control groups. Fluorescence microscopy of sections of the cell-treated joints of all animals indicated that the GFP-transduced injected cells have participated effectively in the reparative process of the damaged articular surface and have integrated within the existing articular cartilage. The cells were associated with the surface of the cartilage and, were also detected in the interior.</p> <p>Conclusions</p> <p>Homing was confirmed by the incorporation of injected GFP-labeled MSCs within the repaired newly formed cartilage. Significant recovery proves that the use of IA injection of autologous MSCs is a viable and a practical option for treating different degrees of osteoarthritis.</p
INCREASED URINARY 8-OXO-7,8-DIHYDRO-2′-DEOXYGUANOSINE EXCRETION IN A SAMPLE OF EGYPTIAN CHILDREN WITH BETA THALASSEMIA MAJOR: MARKER FOR LIPID PEROXIDATION-INDUCED DNA DAMAGE
Objective: The objective of this research was to evaluate oxidative stress status in children with β-thalassemia major.Methods: Our study was conducted in children with β-thalassemia aged from 5 to 15 years. Investigate the urinary excretion of human 8-oxo-7,8- dihydro-2′-deoxyguanosine, which will be analyzed by enzyme-linked immunosorbent assay. To investigate serum levels of antioxidant enzymes include glutathione s-transferase (GST) and catalase (CAT).Results: We found a significant elevation of the urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine level with p=0.001 compared to control group, a significant reduction of both GST and CAT p=0.05 and 0.03, respectively, compared to control group. There was a significant negative correlation between urinary 8-oxo-7,8-dihydro-2′-deoxyguanisine and CAT level, r=−0.378, p=0.016, hemoglobin - r=−0.610, p=0.001, hematocrit (%) - r=−0.478, p=0.002, while a significant positive correlation between urinary 8-oxo-7,8-dihydro-2′-deoxyguanisine and alanine aminotransferase - r=0.547, p=0.001, and serum ferritin - r=0.391, p=0.013. There was a significant negative correlation between CAT and serum ferritin - r=−0.320, p=0.44.Conclusion: We conclude that the strongly increased urinary excretion 8-oxo-7,8=dihydro-2′-deoxyguanisine indicates elevated lipid peroxidation induced DNA damage in internal organs such as the liver. These highly pro mutagenic lesions may contribute to the increased risk of thalassemia patients to develop hepatocellular carcinoma
URINARY MARKERS OF OXIDATIVE DNA DAMAGE IN TYPE 1 DIABETIC CHILDREN: RELATION TO MICROVASCULAR COMPLICATIONS
  Objective: Type 1 diabetes mellitus (T1DM) is a widespread metabolic disease, which frequently carries with it a significant impact on human health. Oxidative damage and tissue inflammation have been claimed to be a typical pathogenic component for the progression of diabetic complications. We aim in this study to explore the relation of urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) (as a marker of nucleic acid oxidation) to microvascular complications in T1DM.Methods: A case–control study, enrolling 45 T1DM children and an equivalent number of healthy subjects, was performed. Full clinical examination and anthropometric measurement were performed to all subjects. Urinary assessment for 8-oxodG and albumin was done in addition to blood sampling for lipid profile and glycated Hb (HbA1c) assay. Complete ocular examination for assessment of diabetic retinopathy (DR) was also done.Results: Levels of urinary 8-oxodG, serum cholesterol, triglycerides, and low-density lipoprotein in cases were significantly higher than non-diabetics; these levels were likewise higher in uncontrolled T1DM patients in comparison with well-controlled T1DM subjects. Urinary 8-oxodG and HbA1c were significantly higher in diabetic patients with albuminuria and DR compared to patients without complications. Significant positive correlation was found between 8-oxodG with HbA1c (r=0.8, p<0.01), diastolic blood pressure (DBP) (r=0.4, p=0.02), and cholesterol (r=0.4, p=0.05).Conclusion: Urinary 8-oxodG was found to be a reliable marker for assessing oxidative DNA damage in T1DM and can be used in the determination of microvascular complications related to diabetes
Towards a canonical classical natural deduction system
This paper studies a new classical natural deduction system, presented as a typed calculus named \lml. It is designed to be
isomorphic to Curien-Herbelin's calculus, both at the level of proofs and reduction, and the isomorphism is based on the correct correspondence between cut (resp. left-introduction) in sequent calculus, and substitution (resp. elimination) in natural deduction. It is a combination of Parigot's -calculus with the idea
of ``coercion calculus'' due to Cervesato-Pfenning, accommodating let-expressions in a surprising way: they expand Parigot's syntactic class of named terms.
This calculus aims to be the simultaneous answer to three problems. The first problem is the lack of a canonical natural deduction
system for classical logic. \lml is not yet another classical calculus, but rather a canonical reflection in natural deduction of
the impeccable treatment of classical logic by sequent calculus. The second problem is the lack of a formalization of the usual semantics
of Curien-Herbelin's calculus, that explains co-terms and cuts as, respectively, contexts and hole-filling instructions. The mentioned
isomorphism is the required formalization, based on the precise notions of context and hole-expression offered by \lml. The third
problem is the lack of a robust process of ``read-back'' into natural deduction syntax of calculi in the sequent calculus format,
that affects mainly the recent proof-theoretic efforts of derivation of -calculi for call-by-value. An isomorphic counterpart
to the -subsystem of Curien-Herbelin's-calculus is derived, obtaining a new
-calculus for call-by-value, combining control and let-expressions.Fundação para a Ciência e a Tecnologia (FCT
Spin and Rotations in Galois Field Quantum Mechanics
We discuss the properties of Galois Field Quantum Mechanics constructed on a
vector space over the finite Galois field GF(q). In particular, we look at
2-level systems analogous to spin, and discuss how SO(3) rotations could be
embodied in such a system. We also consider two-particle `spin' correlations
and show that the Clauser-Horne-Shimony-Holt (CHSH) inequality is nonetheless
not violated in this model.Comment: 21 pages, 11 pdf figures, LaTeX. Uses iopart.cls. Revised
introduction. Additional reference
Causes and risk factors for common mental illnesses : the beliefs of paediatric hospital staff in the United Arab Emirates
Background
Children and adolescents with chronic physical health conditions are vulnerable to poor mental health outcomes. The measurement of mental health literacy of health professionals working with such populations is important because of their role in promoting early and appropriate help-seeking. This study sought to determine the beliefs regarding the causes of and risks factors for three types of mental illnesses amongst health professionals in United Arab Emirates.
Method
A culturally validated mental health literacy survey presenting three vignettes of fictional characters meeting diagnostic criteria for posttraumatic stress disorder, depression with suicidal thoughts and psychosis was distributed. The survey measured health care professionals’ beliefs regarding the causes of and risk factors for these disorders.
Results
A total of 317 health care professional (> 90% nurses) were surveyed from across the UAE. Although 43.8% correctly endorsed exposure to a ‘traumatic event’ as the most likely cause for developing posttraumatic stress disorder, there was a more limited understanding of the contribution of biopsychosocial factors to the development of the mental illness, particularly for psychosis. Participant socio-demographic variables were associated with attributions of religious or spiritual beliefs and personal weakness as causal and/or vulnerability factors in the development of depression with suicidal thoughts and psychosis.
Conclusions
Efforts to improve mental health systems and health care providers in UAE and other similar Middle Eastern countries requires targeted mental health literacy programs that seek to integrate biopsychosocial models of mental illness and their treatment with the positive aspects of religious and cultural beliefs that are dominant in this region
Influence of Interleukin-6 (174G/C) Gene Polymorphism on Obesity in Egyptian Children
BACKGROUND: Obesity is a multi-factorial chronic disorder. A considerable number of studies have been performed to figure out whether there is an association between obesity and polymorphisms of gene IL-6 (174G/C), but the results are equivocal.AIM: This study aimed to find out whether the IL-6 (174G/C) gene was associated with the risk of developing obesity in Egyptian children.SUBJECTS AND METHODS: The study included 149 children and adolescents with age ranged between 9.5 – 18 years. Eighty-five of them were obese which BMIZ-score is > 2, and sixty-four children with BMIZ-score ≤ 2 served as control group. Serum level of IL-6 and genetic analysis for IL-6 (174G/C) gene polymorphism were done.RESULTS: Obese children had significantly higher serum levels of IL-6 as compared to those of control children (P = 0.003). A high percentage of IL-6 polymorphism GC was found in obese subjects (93.7%), while the control group had a higher percentage of IL-6 polymorphism GG (70.6 %).CONCLUSION: Our study showed that carriers of the C allele for the IL-6 (174G/C) polymorphism have higher BMI. As the G174C polymorphism is likely to affect IL-6 expression and its physiological regulation; consequently this polymorphism may affect adiposity
Pentraxin 3: A Potential Novel Predictor for Neonatal Pulmonary Hypertension
BACKGROUND: Persistent pulmonary hypertension of the newborn (PPHN) is a serious neonatal problem which has a high mortality rate even with advanced modes of mechanical ventilation. Pentraxin 3 is one of the long pentraxins, which plays an essential role in regulation of cell proliferation and angiogenesis.
AIM: This study aims to assess serum pentraxin 3 levels in neonates with pulmonary arterial hypertension and compare them in those who have other congenital heart diseases and healthy neonates. Also, we intended to evaluate serum levels of CRP as a mediator of inflammation in the studied groups.
METHODS: The study is a case-control study. Cases were recruited from El Galaa Teaching Hospital, classified into three groups; each group had thirty cases. The first one: cases with pulmonary hypertension (PHT), the second one: cases with congenital heart diseases (CHD) without pulmonary hypertension and the third group included healthy neonates. All participants were subjected to full history taking and full clinical examination. Diagnosis of congenital heart disease and pulmonary hypertension was made according to echocardiographic ï¬ndings by pediatric cardiologist using echocardiography machine. Laboratory investigations included measurement of serum pentraxin 3, Routine CBC, CRP.
RESULTS: This study found that the mean serum pentraxin 3 in PHT neonates was significantly higher than that of the control and CHD neonates (p ≤ 0.001, p = 0.02 respectively). Also, the mean Pentraxin3 of the CHD neonates was significantly higher than that of the control (p = 0.06). Also, the mean CRP of the PHT neonates was significantly higher than that of the control (p = 0.01). Regression analysis showed that Pentraxin3 was the main predictor of PAP (P = 0.01).
CONCLUSION: Serum pentraxin 3 is significantly elevated in neonates with pulmonary hypertension, so measurement of pentraxin 3 levels in neonates may be valuable as a predictor for pulmonary hypertension in neonates
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