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https://www.readbyqxmd.com/read/28535125/preparation-and-characterization-of-adefovir-dipivoxil-stearic-acid-cocrystal-with-enhanced-physicochemical-properties
#1
Jeong-Woong Seo, Kyu-Min Hwang, Sung-Hoon Lee, Dong-Wook Kim, Eun-Seok Park
The objectives of this study were to prepare cocrystal composed of adefovir dipivoxil (AD) and stearic acid (SA) and to investigate the enhanced properties of the cocrystal. The cocrystal was prepared by antisolvent precipitation and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). The enhanced properties were evaluated by dissolution testing, permeability studies, and powder rheology analysis...
May 23, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28534498/estimating-the-basal-metabolic-rate-from-fat-free-mass-in-individuals-with-motor-complete-spinal-cord-injury
#2
S M Chun, H-R Kim, H I Shin
STUDY DESIGN: Cross-sectional study. OBJECTIVES: This study aimed to validate the existing basal metabolic rate (BMR) predictive equations that include fat free mass (FFM) as an independent variable and, based on the FFM assessment, to develop a new SCI population-specific equation. SETTING: Outpatient clinic in a general hospital. METHODS: Our study group was formed of 50 individuals with chronic motor complete SCI: 27 patients with tetraplegia and 23 with paraplegia...
May 23, 2017: Spinal Cord
https://www.readbyqxmd.com/read/28534300/formulation-and-evaluation-of-naringenin-nanosuspensions-for-bioavailability-enhancement
#3
Sonia Gera, Sreekanth Talluri, Nagarjun Rangaraj, Sunitha Sampathi
The clinical potential of naringenin (NRG) is compromised due to its poor aqueous solubility and low oral bioavailability. The study is aimed at addressing these issues by means of naringenin nanosuspensions (NRG-NS) formulated using polyvinylpyrrolidone (PVP K-90) as stabiliser via antisolvent sonoprecipitation method. Optimisation of sonication time, drug concentration and stabilisers was done based on particle size. Characterisation of pure NRG and NRG-NS was carried out by scanning electron microscopy, differential scanning calorimetry (DSC), x-ray powder diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR)...
May 22, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28534299/adsorption-onto-mesoporous-silica-using-supercritical-fluid-technology-improves-dissolution-rate-of-carbamazepine-a-poorly-soluble-compound
#4
Aditya V Gandhi, Priyanka Thipsay, Bharat Kirthivasan, Emilio Squillante
The purpose of this research was to design and characterize an immediate-release formulation of carbamazepine (CBZ), a poorly soluble anti-epileptic drug, using a porous silica carrier. Carbon dioxide in its supercritical state (2000 psi, 30-35°C) was used as an anti-solvent to precipitate CBZ onto two particle size variants of silica. Adsorption isotherms were used as a pre-formulation strategy to select optimum ratios of silica and CBZ. The obtained drug-silica formulations were characterized by dissolution studies, differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM)...
May 22, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28534056/carbon-nanomaterials-enhance-survival-of-agapanthus-praecox-callus-after-cryopreservation-by-vitrification
#5
S M Chen, L Ren, D Zhang, Y F Zhang, X H Shen
BACKGROUND: Adding exogenous compounds is an effective way to improve cell survival after cryopreservation. Carbon nanomaterials (CNMs) are novel exogenous substances with small particle size and good biocompatibility. OBJECTIVE: In this work, four types of CNMs were used for the cryopreservation of Agapanthus praecox callus and their possible effects and mechanism of action were analyzed. MATERIALS AND METHODS: The thermal properties of the vitrification solutions tested were detected by differential scanning calorimetry...
March 2017: Cryo Letters
https://www.readbyqxmd.com/read/28533680/preparation-characterization-and-in-vitro-vivo-studies-of-oleanolic-acid-loaded-lactoferrin-nanoparticles
#6
Xiaojing Xia, Haowei Liu, Huixia Lv, Jing Zhang, Jianping Zhou, Zhiying Zhao
Oleanolic acid (OA), a pentacyclic triterpene, is used to safely and economically treat hepatopathy. However, OA, a Biopharmaceutics Classification System IV category drug, has low bioavailability owing to low solubility (<1 μg/mL) and biomembrane permeability. We developed a novel OA nanoparticle (OA-NP)-loaded lactoferrin (Lf) nanodelivery system with enhanced in vitro OA dissolution and improved oral absorption and bioavailability. The OA-NPs were prepared using NP albumin-bound technology and characterized using dynamic light scattering, scanning electron microscopy, X-ray powder diffraction, differential scanning calorimetry, and in vitro dissolution test...
2017: Drug Design, Development and Therapy
https://www.readbyqxmd.com/read/28533433/changes-in-the-dynamics-of-the-cardiac-troponin-c-molecule-explain-the-effects-of-ca-2-sensitizing-mutations
#7
Charles M Stevens, Kaveh Rayani, Gurpreet Singh, Bairam Lotfalisalmasi, D Peter Tieleman, Glen F Tibbits
Cardiac troponin C (cTnC) is the regulatory protein that initiates cardiac contraction in response to Ca(2+) TnC binding Ca(2+) initiates a cascade of protein-protein interactions that begins with the opening of the N-terminal domain of cTnC, followed by cTnC binding the Troponin I switch peptide (TnISW). We have evaluated, through isothermal titration calorimetry (ITC) and MD simulation, the effect of several clinically relevant mutations (A8V, L29Q, A31S, L48Q, Q50R and C84Y) on the Ca(2+) affinity, structural dynamics, and calculated interaction strengths between cTnC and each of Ca(2+) and TnISW Surprisingly the Ca(2+) affinity measured by ITC was only significantly affected by half of these mutations, with the exceptions of the L48Q, Q50R and C84Y mutants, which had an affinity 10-fold, 3-fold and 3-fold higher than wild-type, respectively...
May 22, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28533263/prior-weight-loss-exacerbates-the-biological-drive-to-gain-weight-after-the-loss-of-ovarian-function
#8
Vanessa D Sherk, Matthew R Jackman, Erin D Giles, Janine A Higgins, Rebecca M Foright, David M Presby, Ginger C Johnson, Julie A Houck, Jordan L Houser, Robera Oljira, Paul S MacLean
Both the history of obesity and weight loss may change how menopause affects metabolic health. The purpose was to determine whether obesity and/or weight loss status alters energy balance (EB) and subsequent weight gain after the loss of ovarian function. Female lean and obese Wistar rats were randomized to 15% weight loss (WL) or ad libitum fed controls (CON). After the weight loss period, WL rats were kept in EB at the reduced weight for 8 weeks prior to ovariectomy (OVX). After OVX, all rats were allowed to eat ad libitum until weight plateaued...
May 2017: Physiological Reports
https://www.readbyqxmd.com/read/28532677/predicting-melt-rheology-for-hot-melt-extrusion-by-means-of-a-simple-tg-measurement
#9
Esther S Bochmann, Elgin E Üstüner, Andreas Gryczke, Karl G Wagner
The feasibility of predicting melt rheology by using the glass transition temperature (Tg) of a desired amorphous solid dispersion (ASD) for hot-melt extrusion (HME) and other melt based processes is presented. Three groups of three different active pharmaceutical ingredients (APIs) or plasticizer/copovidone mixtures, with identical glass transition in rheological testing, were used. Their rheological behavior as a function of temperature and frequency were analyzed by means of small amplitude oscillatory shear (SAOS) on an oscillatory rheometer...
May 19, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28532097/influence-of-telopeptides-on-the-structural-and-physical-properties-of-polymeric-and-monomeric-acid-soluble-type-i-collagen
#10
Róisín Holmes, Steve Kirk, Giuseppe Tronci, Xuebin Yang, David Wood
Currently two factors hinder the use of collagen as building block of regenerative devices: the limited mechanical strength in aqueous environment, and potential antigenicity. Polymeric collagen is naturally found in the cross-linked state and is mechanically tougher than the monomeric, acid-soluble collagen ex vivo. The antigenicity of collagen, on the other hand, is mainly ascribed to inter-species variations in amino acid sequences of the non-helical terminal telopeptides. These telopeptides can be removed through enzymatic treatment to produce atelocollagen, although the effect of this cleavage on triple helix organization, amino acidic composition and thermal properties is often disregarded...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532050/full-in-vitro-analyses-of-new-generation-bulk-fill-dental-composites-cured-by-halogen-light
#11
Tuçe Hazal Tekin, Aysel Kantürk Figen, Pınar Yılmaz Atalı, Bilge Coşkuner Filiz, Mehmet Burçin Pişkin
The objective of this study was to investigate the full in-vitro analyses of new-generation bulk-fill dental composites cured by halogen light (HLG). Two types' four composites were studied: Surefill SDR (SDR) and Xtra Base (XB) as bulk-fill flowable materials; QuixFill (QF) and XtraFill (XF) as packable bulk-fill materials. Samples were prepared for each analysis and test by applying the same procedure, but with different diameters and thicknesses appropriate to the analysis and test requirements. Thermal properties were determined by thermogravimetric analysis (TG/DTG) and differential scanning calorimetry (DSC) analysis; the Vickers microhardness (VHN) was measured after 1, 7, 15 and 30days of storage in water...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532029/surfactin-loaded-polyvinyl-alcohol-pva-nanofibers-alters-adhesion-of-listeria-monocytogenes-to-polystyrene
#12
J J Ahire, D D Robertson, A J van Reenen, L M T Dicks
Surfactin-loaded polyvinyl alcohol (PVA) nanofibers were spun using gravity electrospinning. Scanning electron microscopy (SEM) images showed that nanofibers spun with surfactin are free from bead formation and uniform in diameter. The average nanofiber diameters were decreased (273±39nm, 259±39nm and 217±33nm) with increasing levels of surfactin (0.5, 1.0 and 1.5%, w/v) into PVA (10%, w/v). The 10% (w/v) PVA had average fiber diameter of 303±33nm. Atomic force microscopy (AFM) analysis showed that fibers spun with surfactin are not smooth as PVA fibers...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532019/characterization-of-bladder-acellular-matrix-hydrogel-with-inherent-bioactive-factors
#13
Dan Jiang, Jianwen Huang, Huili Shao, Xuechao Hu, Lujie Song, Yaopeng Zhang
Bladder acellular matrix (BAM) hydrogel may have great potential in tissue engineering due to outstanding biocompatibility and the presence of inherent bioactive factors in BAM. In this study, we prepared the BAM hydrogel by the method of enzymatic solubilization with pepsin and characterize the microrheological properties of the BAM precursor solution. The structures of the BAM hydrogel were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC)...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531996/poly-epsilon-caprolactone-nanoparticles-enhance-ursolic-acid-in-vivo-efficacy-against-trypanosoma-cruzi-infection
#14
Juliana Palma Abriata, Josimar O Eloy, Thalita Bachelli Riul, Patricia Mazureki Campos, Marcelo Dias Baruffi, Juliana Maldonado Marchetti
Despite affecting millions of people worldwide, Chagas disease is still neglected by the academia and industry and the therapeutic option available, benznidazole, presents limited efficacy and side effects. Within this context, ursolic acid may serve as an option for treatment, however has low bioavailability, which can be enhanced through the encapsulation in polymeric nanoparticles. Therefore, herein we developed ursolic acid-loaded nanoparticles with poly-ε-caprolactone by the nanoprecipitation method and characterized them for particle size, zeta potential, polydispersity, encapsulation efficiency, morphology by scanning electron microscopy and thermal behavior by differential scanning calorimetry...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531991/multifunctional-polymer-drug-loading-system-with-ph-sensitive-fluorescent-and-targeting-property
#15
Xuening Fei, Shubei Li, Lingyun Cao, Baolian Zhang, Miaozhuo Yu
IA multifunctional drug loading system with pH-sensitive, fluorescent and targeting property was fabricated. Firstly, the amphipathic N-octyl-N'-(2-carboxyl-cyclohexamethenyl) chitosan (OCCC) was prepared by grafting hydrophobic octyl group and hydrophilic hexahydrophthalic anhydride onto chitosan, then it was modified with folic acid (FA) and thiazole orange (TO) using polyethylene glycol (PEG) as the link to fabricate a multifunctional drug loading system TO-PEG-OCCC-PEG-FA. Its chemical structure was determined by Fourier transform infrared spectroscopy (FT-IR), elemental analysis, differential scanning calorimetry (DSC) analysis, UV-vis and fluorescence spectrometer, and the results showed that the substitution degree of hydrophobic/hydrophilic group onto chitosan were 41...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531789/do-picu-patients-meet-technical-criteria-for-performing-indirect-calorimetry
#16
Megan R Beggs, Gonzalo Garcia Guerra, Bodil M K Larsen
BACKGROUND & AIMS: Indirect calorimetry (IC) is considered gold standard for assessing energy needs of critically ill children as predictive equations and clinical status indicators are often unreliable. Accurate assessment of energy requirements in this vulnerable population is essential given the high risk of over or underfeeding and the consequences thereof. The proportion of patients and patient days in pediatric intensive care (PICU) for which energy expenditure (EE) can be measured using IC is currently unknown...
October 2016: Clinical Nutrition ESPEN
https://www.readbyqxmd.com/read/28531779/overweight-postmenopausal-women-with-different-plasma-estradiol-concentrations-present-with-a-similar-pattern-of-energy-expenditure-and-substrate-oxidation-rate-before-and-after-a-fatty-meal-challenge
#17
Roberta de Souza Santos, Andressa Feijó da Silva Santos, Deborah J Clegg, Odilon Iannetta, Julio Sérgio Marchini, Vivian Marques Miguel Suen
Menopause-related withdrawal of ovarian estrogens is associated with reduced energy metabolism and overall impairment of substrate oxidation. Estradiol's withdrawal after menopause is associated with a reduction in energy metabolism and impaired substrate oxidation, which contributes to weight gain and visceral fat accumulation. Here we aimed to investigate the association between plasma estradiol concentrations and energy expenditure (EE)/substrate oxidation in a group of overweight postmenopausal women before and after a fatty meal challenge...
October 2016: Clinical Nutrition ESPEN
https://www.readbyqxmd.com/read/28531774/clinical-assessment-underestimates-fat-mass-and-overestimates-resting-energy-expenditure-in-children-with-neuromuscular-diseases
#18
Salesa Barja, Regina Pérez
BACKGROUND: Nutritional problems are frequent among patients with neuromuscular diseases, who consequently need an adequate evaluation. OBJECTIVE: to describe nutritional assessment and to estimate and measure body composition and energy requirement in children with neuromuscular diseases. SUBJECTS AND METHODS: We performed anthropometry, skinfold measurement and bioelectric impedance analysis (BIA) for estimate and measure, respectively, fat mass (FM)...
October 2016: Clinical Nutrition ESPEN
https://www.readbyqxmd.com/read/28531773/impact-of-metabolic-syndrome-on-resting-energy-expenditure-in-patients-with-chronic-kidney-disease
#19
Carolina Q D Rodrigues, Jacqueline A P Santos, Beata M R Quinto, Mauro S M Marrocos, Andrei A Teixeira, Cássio J O Rodrigues, Marcelo C Batista
BACKGROUND & AIMS: Resting energy expenditure (REE) changes in patients with chronic kidney disease (CKD) may contribute to mortality increase. The obesity and inflammation is associated with high REE and when not compensated by adequate intake, may determine an unfavorable clinical outcome in this population. We aimed to evaluate the influence of metabolic syndrome (MetS) on REE in CKD patients. METHODS: One hundred eighty-three patients were stratified according to glomerular filtration rate (GFR) and divided in groups: without CKD (GFR > 60 ml/min/1...
October 2016: Clinical Nutrition ESPEN
https://www.readbyqxmd.com/read/28531450/estimating-energy-expenditure-in-vascular-surgery-patients-are-predictive-equations-accurate-enough
#20
J Suen, J M Thomas, C L Delaney, J I Spark, M D Miller
BACKGROUND & AIMS: Malnutrition is prevalent in vascular surgical patients who commonly seek tertiary care at advanced stages of disease. Adjunct nutrition support is therefore pertinent to optimise patient outcomes. To negate consequences related to excessive or suboptimal dietary energy intake, it is essential to accurately determine energy expenditure and subsequent requirements. This study aims to compare resting energy expenditure (REE) measured by indirect calorimetry, a commonly used comparator, to REE estimated by predictive equations (Schofield, Harris-Benedict equations and Miller equation) to determine the most suitable equation for vascular surgery patients...
December 2016: Clinical Nutrition ESPEN
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