50 research outputs found

    19F-nuclear magnetic resonance spectroscopy as a tool to investigate host-guest complexation of some antidepressant drugs with natural and modified cyclodextrins

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    Purpose: 19F-Nuclear magnetic resonance spectroscopy (19F-NMR) was used to study host-guest complexation of three fluorine containing antidepressant drugs, viz, fluoxetine hydrochloride, citalopram hydrobromide and fluvoxamine maleate, with various cyclodextrins (CD), including α-, β-cyclodextrin, methylated α-cyclodextrin (M-α-CD), diamino derivative of methylated α-cyclodextrin, (DAM-α-CD) and tetramino derivative of methylated α-cyclodextrin (TAM-α-CD).Methods: Using the mole ratio method, a 1:1 stoichiometry was determined for the resulting inclusion complexes. 19F chemical shifts were used to determine the formation constant of the complexes. Experiments were performed with solutions containing 0.001 M drug and various concentrations of CDs. NMR data were plotted as 19F chemical shift versus CD/drug mole ratio, and fitted using the nonlinear least-squares curve fitting program, KINFIT, to obtain the formation constant of CD-drug complex. Molecular modeling (MM) calculations were used to predict the geometry of the complex of fluvoxamine and β-CD. Molecular modeling studies were performed in vacuum phase, employing empirical force fields and semi-empirical quantum theory using AM1 Hamiltonian.Results: Complex formation caused separation of the fluorine peaks that can be assigned to the two enantiomers of fluoxetine hydrochloride. Molecular modeling data suggest that fluvoxamine/β-CD inclusion complexes have a 1:1 stoichiometry and that the CF3-substituted ring of fluvoxamine is embedded in the cavity of β-CD, indicating a good agreement between molecular modeling calculation and experimental data (NMR data).Conclusion: One-dimensional 19F-NMR is a fast and convenient method for the determination of complex stoichiometry and complexation constants of natural and modified CDs and fluorinated drugs.Keywords: Antidepressant drugs, Cyclodextrins, Complexation, Inclusion complex, Formation constant, 19F-NM

    Push Recovery of a Position-Controlled Humanoid Robot Based on Capture Point Feedback Control

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    In this paper, a combination of ankle and hip strategy is used for push recovery of a position-controlled humanoid robot. Ankle strategy and hip strategy are equivalent to Center of Pressure (CoP) and Centroidal Moment Pivot (CMP) regulation respectively. For controlling the CMP and CoP we need a torque-controlled robot, however most of the conventional humanoid robots are position controlled. In this regard, we present an efficient way for implementation of the hip and ankle strategies on a position controlled humanoid robot. We employ a feedback controller to compensate the capture point error. Using our scheme, a simple and practical push recovery controller is designed which can be implemented on the most of the conventional humanoid robots without the need for torque sensors. The effectiveness of the proposed approach is verified through push recovery experiments on SURENA-Mini humanoid robot under severe pushes

    Maternal Vitamin D Status among Different Ethnic Groups and Its Potential Contribution to Adverse Pregnancy and Child Outcomes

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    Maternal vitamin D deficiency in pregnancy is a widespread public health concern. Race and ethnicity as biological and cultural factors, respectively, can affect vitamin D status through differences in skin color, sunlight exposure, and dietary intake. Low maternal vitamin D status in pregnancy may affect both mother and fetus adversely. Vitamin D deficiency and insufficiency are linked to a wide variety of adverse pregnancy outcomes such as gestational diabetes, preeclampsia, and preterm delivery. Furthermore, maternal vitamin D deficiency has been linked to several adverse health outcomes in infants and children. The examples include, but not limited to, impaired growth, skeletal problems, and autoimmune diseases such as type 1 diabetes and asthma. This chapter reviews the vitamin D status during pregnancy across different ethnic groups, looking into the adverse pregnancy and child outcomes, followed by a discussion on the association between maternal and child vitamin D status and successful interventions. Strong evidence exists about the association between vitamin D and some health outcomes during pregnancy, while more studies are needed to confirm the other claim. The existing body of evidence justifies the need for well-designed policies and systematic interventions to ensure optimal vitamin D status of pregnant women and their offsprings across different ethnic and racial groups

    Association of Neonatal Asphyxia With Serum Levels of Heat Shock Protein 27 in a Small Sample of Newborns

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    Abstract- Neonatal asphyxia is a state of hypoxia and hypercapnia caused by failure to breathe spontaneously and regularly soon after birth. Heat shock proteins (HSPs) are a ubiquitous and diverse group of highly conserved proteins which are rapidly up-regulated following periods of cellular stress including exposure to heat, ultraviolet irradiation, or chemical toxicity. The aim of the current study was to explore whether there is a relation between serum levels of HSP27 and neonatal asphyxia in a small sample of newborns. A total of 25 healthy newborns and 25 newborns diagnosed with neonatal asphyxia were recruited form Imam Reza Hospital, Mashhad, Iran. The Apgar score was recorded at one minute after delivery by trained nurses and newborns with the Apgar score of less than 7 were considered to be asphyctic. The mean birth weight of newborns in the case and control groups were 3110.47±613.5 g and 3230.4±584.83 g, respectively (P=0.4). Moreover, the mean maternal age of infants in the case group was higher than the mean maternal age of infants in the control group (31.1±6.1 vs. 30.1±5.0). Although it was marginally significant, the level of HSP27 was higher in the case group than the control group (0.23±0.08 vs. 0.19±0.09; P=0.07). Levels of HSP27 were found to be higher in newborns with neonatal asphyxia compared with healthy controls

    The prognostic value of long noncoding RNA MEG3 expression in the survival of cancer patients: a meta-analysis

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    Long non-coding RNAs (lncRNAs) play an important role in carcinogenesis and cancer progression. lncRNA MEG3 is a tumor suppressor that is down-regulated in several cancers. However, its prognostic value in human malignancies remains controversial. We have therefore undertaken a meta-analysis to explore the relationship between cancer survival and the expression of long non-coding RNA MEG3. A systematic literature search identified 13 potentially eligible investigations comprising 1733 patients in nine different cancer types. In the pooled analysis, a low expression of MEG3 was associated with a low overall survival (OS) in cancer patients with a combined HR of 0.830 [hazard ratio (HR) =0.83; 95% CI: 0.70–0.98; P=0.0.03; random effect model]. However, sub-group analysis according to cancer type revealed that MEG3 expression was not associated with better OS in gastrointestinal cancer (HR = 0.58, 95% CI = 0.33 to 1.03, P = 0.06) and breast cancer patients (HR = 0.85, 95% CI: 0.12 to 5.88, P = 0.87). In conclusion, our results demonstrate that only in the pooled analysis, there was a significant relationship between MEG3 expression and cancer survival. Further investigation of other molecular biomarkers involved in tumorigenesis-related pathways is necessary
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