Spin polarized liquid 3He

We have employed the constrained variational method to study the influence of spin polarization on the ground state properties of liquid $^3{\rm He}$. The spin polarized phase, we have found, has stronger correlation with respect to the unpolarized phase. It is shown that the internal energy of liquid $^3{\rm He}$ increases by increasing polarization with no crossing point between polarized and unpolarized energy curves over the liquid density range. The obtained internal energy curves show a bound state, even in the case of fully spin polarized matter. We have also investigated the validity of using a parabolic formula for calculating the energy of spin polarized liquid $^3{\rm He}$. Finally, we have compared our results with other calculations.Comment: 16 pages, 6 figure

Finite temperature calculations for the bulk properties of strange star using a many-body approach

We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetric nuclear matter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.Comment: 21 pages, 2 tables, 12 figures Astrophys. (2011) accepte

Acylated ghrelin, growth hormone and IGF-1 levels in the cord blood of small for gestational age newborns

Background: Ghrelin is a pleiotropic hormone that regulates feeding and energy balance and stimulates growth hormone release. Ghrelin also exerts developmental and organizational effects during prenatal life. Objectives: The aim of this study was to determine ghrelin levels in cord blood of small for gestational age (SGA) infants and its association with GH (growth hormone) and IGF-1 levels (insulin-like growth factor-1). Methods: Cord blood sample was obtained from 31 SGA and 25 appropriate for gestational age (AGA) infants. Acylated ghrelin, GH, and IGF-1 levels were measured by enzyme-linked immunosorbent assay. Results: No significant differences were observed in ghrelin and GH concentrations between SGA and AGA infants. However, IGF-1 levels were significantly lower in SGA infants. Cord blood ghrelin was negatively correlated with the infants' birth weight (r = -0.33, P = 0.013); on the other hand, IGF-1 level was positively correlated with birth weight (r = 0.43, P = 0.002). Conclusions: IGF-1 has the most significant effect on intrauterine growth. Acylated ghrelin is detectable in cord blood and correlated with birth weight, suggesting a role in intrauterine development, but its level is not affected by intrauterine growth retardation. © 2016, Iranian Society of Pediatrics

Structure of Neutron Star with a Quark Core

The equation of state of de-confined quark matter within the MIT bag model is calculated. This equation of state is used to compute the structure of a neutron star with quark core. It is found that the limiting mass of the neutron star is affected considerably by this modification of the equation of state. Calculations are carried out for different choices of the bag constant.Comment: 19 pages, 8 figure

Troppo - A Python framework for the reconstruction of context-specific metabolic models

The surge in high-throughput technology availability for molecular biology has enabled the development of powerful predictive tools for use in many applications, including (but not limited to) the diagnosis and treatment of human diseases such as cancer. Genome-scale metabolic models have shown some promise in clearing a path towards precise and personalized medicine, although some challenges still persist. The integration of omics data and subsequent creation of context-specific models for specific cells/tissues still poses a significant hurdle, and most current tools for this purpose have been implemented using proprietary software. Here, we present a new software tool developed in Python, troppo - Tissue-specific RecOnstruction and Phenotype Prediction using Omics data, implementing a large variety of context-specific reconstruction algorithms. Our framework and workflow are modular, which facilitates the development of newer algorithms or omics data sources.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also thank the PhD scholarships funded by national funds through Fundacao para a Ciencia e Tecnologia, with references: SFRH/BD/133248/2017 (J.F.), SFRH/BD/118657/2016 (V.V.).info:eu-repo/semantics/publishedVersio

Acute renal failure: A rare initial presentation of acute lymphoblastic leukemia

Acute lymphoblastic leukemia has several presentations associated with bone marrow and extramedullary involvement. The unusual presentation may be due to the infiltration of leukemic cells in any organ. An 11-year-old girl presented with fever and vomiting, since one day before admission after starfish biting during swimming. Her vital signs were: blood pressure 150/100 mmHg, pulse 98 beats per minute, respiration 18 breathes per minute, and temperature 37.2 °C (99 F). Laboratory work-up showed blood urea nitrogen 38 mg/dl and creatinine 2.8 mg/dl. In peripheral blood smear, few atypical cells, mild anemia (Hb: 9.2 g/dl), and mild thrombocytopenia (Platelet: 109,000/µL) were detected. Bone marrow aspiration and immunophenotyping were in favor of acute precursor B cell type lymphoblastic leukemia. The patient had a favorable response to treatment after initiating high-risk chemotherapy. Therefore, acute renal failure can be a rare initial presentation of acute lymphoblastic leukemia, and azotemia will improve with an early chemotherapy treatment

Prevalence of meningitis among hospitalized neonates with urinary tract infection

Background: Bacteremia is relatively common in children with urinary tract infection (UTI). The aim of the present study was to determine the frequency of bacterial meningitis among neonates with laboratory-confirmed UTI. Methods: This retrospective cross-sectional study was performed on 163 hospitalized neonates in Ali Asghar and Shahid Akbarabadi hospitals affiliated to Iran University of Medical Sciences in Tehran, Iran. The demographic and clinical data of hospitalized neonates due to UTI during the recent 6 years (2010-2016) who were aged < 28 days and had cerebrospinal fluid (CSF) culture via lumbar puncture were extracted from medical records and recorded in some checklists. Results: A total of 163 neonates with laboratory-confirmed UTI with the mean age of 18.25±5.41 days were included. In this study, 54 of the neonates were male. Out of all neonates, 23 (14.1) cases had positive blood culture. The positive CSF culture was observed in only two (1.2) neonates. Positive voiding cystourethrogram (VCUG) test was reported in 50 of the neonates with positive CSF culture (P=0.047). Although abnormal ultrasound findings related to the urinary tract in positive CSF neonates were higher by approximately twofold, compared to those reported for negative CSF neonates, this difference was not statistically significant (50 and 24.2, respectively; P=0.432). Conclusion: The frequency of the concurrent occurrence of UTI and meningitis in our neonates was 1.2. Out of all indicators associated with meningitis occurrence, positive VCUG may be a risk factor. Further prospective studies are needed to approve these results. © 2020 Mashhad University of Medical Sciences. All rights reserved

Cardioprotective effects of deferoxamine in acute and subacute cardiotoxicities of doxorubicin: a randomized clinical trial

Background: Cardiotoxicity is a major concern following doxorubicin (DOX) use in the treatment of malignancies. We aimed to investigate whether deferoxamine (DFO) can prevent acute cardiotoxicity in children with cancer who were treated with DOX as part of their chemotherapy. Results: Sixty-two newly-diagnosed pediatric cancer patients aged 2–18 years with DOX as part of their treatment regimens were assigned to three groups: group 1 (no intervention, n = 21), group II (Deferoxamine (DFO) 10 times DOX dose, n = 20), and group III (DFO 50 mg/kg, n = 21). Patients in the intervention groups were pretreated with DFO 8-h intravenous infusion in each chemotherapy course during and after completion of DOX infusion. Conventional and tissue Doppler echocardiography, serum concentrations of human brain natriuretic peptide (BNP), and cardiac troponin I (cTnI) were checked after the last course of chemotherapy. Sixty patients were analyzed. The level of cTnI was < 0.01 in all patients. Serum BNP was significantly lower in group 3 compared to control subjects (P = 0.036). No significant differences were observed in the parameters of Doppler echocardiography. Significant lower values of tissue Doppler late diastolic velocity at the lateral annulus of the tricuspid valve were noticed in group 3 in comparison with controls. By using Pearson analysis, tissue Doppler systolic velocity of the septum showed a marginally significant negative correlation with DOX dose (P = 0.05, r = − 0.308). No adverse effect was reported in the intervention groups. Conclusions: High-dose DFO (50 mg/kg) may serve as a promising cardioprotective agent at least at the molecular level in cancer patients treated with DOX. Further multicenter trials with longer follow-ups are needed to investigate its protective role in delayed DOX-induced cardiac damage. Trial registration IRCT, IRCT2016080615666N5. Registered 6 September 2016

Evaluation of rate law approximations in bottom-up kinetic models of metabolism.

BackgroundThe mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question.ResultsIn this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations.ConclusionsOverall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches