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https://www.readbyqxmd.com/read/29240819/use-of-thermal-analysis-coupled-with-differential-scanning-calorimetry-quadrupole-mass-spectrometry-and-infrared-spectroscopy-tg-dsc-qms-ftir-to-monitor-chemical-properties-and-thermal-stability-of-fulvic-and-humic-acids
#1
Patrycja Boguta, Zofia Sokołowska, Kamil Skic
Thermogravimetry-coupled with differential scanning calorimetry, quadrupole mass spectrometry, and Fourier-transform infrared spectroscopy (TG-DSC-QMS-FTIR)-was applied to monitor the thermal stability (in an N2 pyrolytic atmosphere) and chemical properties of natural polymers, fulvic (FA) and humic acids (HA), isolated from chemically different soils. Three temperature ranges, R1, 40-220°C; R2, 220-430°C; and R3, 430-650°C, were distinguished from the DSC data, related to the main thermal processes of different structures (including transformations without weight loss)...
2017: PloS One
https://www.readbyqxmd.com/read/29239606/biosurfactant-protein-interaction-in%C3%AF-uences-of-mannosylerythritol-lipids-a-on-%C3%AE-glucosidase
#2
Linlin Fan, Pu-Jun Xie, Ying Wang, Zisu Huang, Jianzhong Zhou
In this work, the influences of a biosurfactant, mannosylerythritol lipids-A (MEL-A) towards β-glucosidase activity and their molecular interactions were studied by using differential scanning calorimetry (DSC), circular dichroism spectroscopy (CD), isothermal titration calorimetry (ITC) and docking simulation. The enzyme inhibition kinetics data showed that MEL-A at a low concentration (< CMC, 20.0±5.0 μM) enhanced β-glucosidase activity, whereas it inhibited the enzyme activity at higher concentrations more than 20...
December 14, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29237390/chronopharmacokinetic-evaluation-of-budesonide-multiparticulate-systems
#3
Sowjanya Battu, Prasanna Raju Yalavarthi, G V Subbareddy, Uma Maheswara Rao, Jyothshna Devi Katamreddy, Harini Cowdary Vadlamudi
Poor oral absorption of budesonide limits design of its solid oral dosage form. With this context, multiparticulate pulsatile system of budesonide for chronotherapy of nocturnal asthma was aimed in this study. Initially, solid dispersions of budesonide (BD) using sodium starch glycolate (SSG) and guar gum (GG) were developed and characterized. Uniform sized non-pariel seeds (~400 µm) were coated with solid dispersions to obtain immediate (BMP) and controlled release pellets by solution layering technique. Pulsatile drug release pellets (BMPP) were obtained by coating the controlled release pellets with Eudragit L100 and RS 100...
December 12, 2017: Recent Patents on Drug Delivery & Formulation
https://www.readbyqxmd.com/read/29236057/development-of-houttuynia-cordata-extract-loaded-solid-lipid-nanoparticles-for-oral-delivery-high-drug-loading-efficiency-and-controlled-release
#4
Ju-Heon Kim, Jong-Suep Baek, Jin-Kyu Park, Bong-Joo Lee, Min-Soo Kim, Sung-Joo Hwang, Jae-Young Lee, Cheong-Weon Cho
Houttuynia cordata (H. cordata) has been used for diuresis and detoxification in folk medicine as well as a herbal medicine with antiviral and antibacterial activities. H. cordata extract-loaded solid lipid nanoparticles (H-SLNs) were prepared with various concentration of poloxamer 188 or poloxamer 407 by a hot homogenization and ultrasonication method. H-SLNs dispersion was freeze-dried with or without trehalose as a cryoprotectant. The physicochemical characteristics of H-SLNs were evaluated by dynamic laser scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM)...
December 13, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29234526/usefulness-of-urea-as-a-means-of-improving-the-solubility-of-poorly-water-soluble-ascorbyl-palmitate
#5
Yutaka Inoue, Daichi Niiyama, Isamu Murata, Ikuo Kanamoto
The aim of this study was to evaluate complexes of L-ascorbyl palmitate (ASCP) and urea (UR). This evaluation involved differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), near-infrared spectroscopy (NIR), a solubility test, a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, and a mushroom tyrosinase inhibition assay. Physicochemical evaluation revealed that ASCP/UR complexes form at a molar ratio of 1/12. The solubility test revealed that ASCP/UR complexes had increased solubility compared to ASCP...
2017: International Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29230541/theoretical-and-experimental-investigation-into-a-eutectic-system-of-3-4-dinitropyrazole-and-1-methyl-3-4-5-trinitropyrazole
#6
Shuang-Fei Zhu, Shu-Hai Zhang, Rui-Jun Gou, Fu-de Ren
Eutectic mixtures of 3,4-dinitropyrazole (DNP) and 1-methyl-3,4,5-trinitropyrazole (MTNP) were investigated by theoretical and experimental methods. The mass ratio of DNP and MTNP ranged from 0:100 to 100:0. Melting points of the mixtures were predicted through observing the inflection point of a specific volume vs. temperature in molecular dynamics (MD) simulation. The results are in good agreement with experimental results obtained from the differential scanning calorimeter (DSC) study. The binding energy of a 50/50 DNP/MTNP eutectic mixture is lower than those of other mixtures, in accordance with the common sense that the melting point of materials is linked to the strength of intermolecular interactions...
December 11, 2017: Journal of Molecular Modeling
https://www.readbyqxmd.com/read/29229244/the-functional-properties-and-structural-characteristics-of-deamidated-and-succinylated-wheat-gluten
#7
Yanhong Liu, Lingling Zhang, Yongxiang Li, Yang Yang, Fei Yang, Shuo Wang
Wheat gluten protein (WGP) was modified by deamidation and succinylation to improve its functional properties. The properties of deamidated and succinylated WGP were compared with those of unmodified WGP, deamidated WGP and succinylated WGP. Structural analysis was carried out with FTIR. Surface visualization was carried out with SEM and the thermal stability was determined by DSC. The results showed that an acylation level of 73.64% produced the optimal properties for modified WGP. After modification, its functional properties were significantly improved...
December 8, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29227485/solid-liquid-equilibria-for-a-pyrrolidinium-based-common-cation-ternary-ionic-liquid-system-and-for-a-pyridinium-based-ternary-reciprocal-ionic-liquid-system-an-experimental-study-and-a-thermodynamic-model
#8
Meysam Mirarabrazi, Olga Stolarska, Marcin Smiglak, Christian Robelin
The present paper describes an experimental study and a thermodynamic model for the phase diagrams of the common-cation ternary system [C4MPyrr]Cl-[C4MPyrr]Br-[C4MPyrr]BF4 (where [C4MPyrr] refers to 1-butyl-1-methyl-pyrrolidinium) and of the ternary reciprocal system [C2Py], [C4Py]‖Cl, Br (where [CnPy] refers to 1-alkyl-pyridinium). Phase equilibria were measured by Differential Scanning Calorimetry (DSC) for two isoplethal sections in the common-cation pyrrolidinium-based ternary system. Phase diagram measurements were recently performed for the four common-ion binary subsystems and the two diagonal sections in the pyridinium-based ternary reciprocal system...
December 11, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29226149/role-of-p-glycoprotein-inhibitors-in-the-bioavailability-enhancement-of-solid-dispersion-of-darunavir
#9
Saleha Rehman, Bushra Nabi, Mohammad Fazil, Saba Khan, Naimat Kalim Bari, Romi Singh, Shavej Ahmad, Varinder Kumar, Sanjula Baboota, Javed Ali
Objective: The aim of the present study was to improve bioavailability of an important antiretroviral drug, Darunavir (DRV), which has low water solubility and poor intestinal absorption through solid dispersion (SD) approach incorporating polymer with P-glycoprotein inhibitory potential. Methods: A statistical approach where design of experiment (DoE) was used to prepare SD of DRV with incorporation of P-glycoprotein inhibitors. Using DoE, different methods of preparation, like melt, solvent evaporation, and spray drying method, utilizing carriers like Kolliphor TPGS and Soluplus were evaluated...
2017: BioMed Research International
https://www.readbyqxmd.com/read/29225461/risperidone-mucoadhesive-buccal-tablets-formulation-design-optimization-and-evaluation
#10
Burak Çelik
The aim of this study was to design and optimize risperidone (RIS) mucoadhesive buccal tablets for systemic delivery as an alternative route. Direct compression method was used for the preparation of buccal tablets, and screening studies were conducted with different polymers to determine their effects on tablet characteristics. Carbopol® (CP) and sodium alginate (SA) were selected as two polymer types for further optimization studies by applying response surface methodology. Tablet hardness (TH), ex vivo residence time (RT), and peak detachment force (DF) from buccal mucosa were selected as three important responses...
2017: Drug Design, Development and Therapy
https://www.readbyqxmd.com/read/29223713/diagnostic-values-of-dce-mri-and-dsc-mri-for-differentiation-between-high-grade-and-low-grade-gliomas-a-comprehensive-meta-analysis
#11
Jianye Liang, Dexiang Liu, Peng Gao, Dong Zhang, Hanwei Chen, Changzheng Shi, Liangping Luo
RATIONALE AND OBJECTIVES: This study aimed to collect the studies on the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI) in differentiating the grades of gliomas, and evaluate the diagnostic performances of relevant quantitative parameters in glioma grading. MATERIALS AND METHODS: We systematically searched studies on the diagnosis of gliomas with DCE-MRI or DSC-MRI in Medline, PubMed, China National Knowledge Infrastructure database, Cochrane Library, and Embase published between January 2005 and December 2016...
December 6, 2017: Academic Radiology
https://www.readbyqxmd.com/read/29223683/a-method-to-combine-target-volume-data-from-3d-and-4d-planned-thoracic-radiotherapy-patient-cohorts-for-machine-learning-applications
#12
Corinne Johnson, Gareth Price, Jonathan Khalifa, Corinne Faivre-Finn, Andre Dekker, Christopher Moore, Marcel van Herk
BACKGROUND AND PURPOSE: The gross tumour volume (GTV) is predictive of clinical outcome and consequently features in many machine-learned models. 4D-planning, however, has prompted substitution of the GTV with the internal gross target volume (iGTV). We present and validate a method to synthesise GTV data from the iGTV, allowing the combination of 3D and 4D planned patient cohorts for modelling. MATERIAL AND METHODS: Expert delineations in 40 non-small cell lung cancer patients were used to develop linear fit and erosion methods to synthesise the GTV volume and shape...
December 6, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29222025/preparation-and-comparison-of-tacrolimus-loaded-solid-dispersion-and-self-microemulsifying-drug-delivery-system-by-in-vitro-in-vivo-evaluation
#13
Taotao Huo, Chun Tao, Minxin Zhang, Qinghong Liu, Bing Lin, Zhihong Liu, Jialiang Zhang, Meijing Zhang, Haiyue Yang, Jue Wu, Xinrong Sun, Qian Zhang, Hongtao Song
This study aimed to compare the dissolution and the intestinal absorption of tacrolimus in self-microemulsifying drug delivery system (SMEDDS) and solid dispersion (SD). Poloxamer 188 SD was prepared by the combination of the solvent evaporation method and the freeze drying method. Hydroxypropyl methylcellulose (HPMC) SD was prepared by the solvent evaporation method combined with the vacuum drying method. The formation of SD was confirmed by SEM images which showed new solid phases. The SMEDDS was composed of oil (Labrafil M1944 CS 28%), surfactant (Cremophor EL 48%) and co-surfactant (Transcutol P 24%)...
December 5, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/29221707/development-of-a-borreliosis-assay-mannan-coated-polyethylene-sinter-bodies-as-a-new-platform-technology
#14
Mohammed Alasel, Nina Dassinger, Doru Vornicescu, Michael Keusgen
Rapid diagnosis of Lyme borreliosis has been carried out on chemically modified porous polyethylene sinter bodies. Photografting of 2-propenol on sinter body's surface was performed as a first step, introducing active hydroxyl groups as a result of polyalcohol formation. The hydroxyl groups were used for further immobilization and could be linked via 3-aminopropyltriethoxysilane (APTES) to polysaccharides like mannan. Prone to coupling, mannan was activated using N, N'-disuccinimidyl carbonate (DSC) to allow smooth reaction with the primary amine groups of the silane layer...
December 5, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/29221040/polymethyl-methacrylate-pmma-recycling-for-the-production-of-optical-fiber-sensor-systems
#15
Adilson R Prado, Arnaldo G Leal-Junior, Carlos Marques, Samara Leite, Geovane L de Sena, Luiz C Machado, Anselmo Frizera, Moises R N Ribeiro, Maria José Pontes
This paper proposes the recycling of poly (methyl methacrylate) plates, formerly used in LCD monitors to produce polymer optical fibers without cladding for sensor systems and a discussion about the fabrication process of the fiber cladding is briefly presented. After disassembling LCD monitors the acrylic plate is cleaned and submitted to an extrusion process. Extrusion temperatures of 220°C, 230°C and 240°C were applied, and the produced polymer fibers were characterized by infrared and visible spectrometry, as well as evaluated for thermal analysis through differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA)...
November 27, 2017: Optics Express
https://www.readbyqxmd.com/read/29220331/regenerative-potential-of-secretome-from-dental-stem-cells-a-systematic-review-of-preclinical-studies
#16
Suleiman Alhaji Muhammad, Norshariza Nordin, Sharida Fakurazi
Injury to tissues is a major clinical challenge due to the limited regenerative capacity of endogenous cells. Stem cell therapy is evolving rapidly as an alternative for tissue regeneration. However, increasing evidence suggests that the regenerative ability of stem cells is mainly mediated by paracrine actions of secretome that are generally secreted by the cells. We aimed to systematically evaluate the efficacy of dental stem cell (DSC)-conditioned medium in in vivo animal models of various tissue defects...
December 8, 2017: Reviews in the Neurosciences
https://www.readbyqxmd.com/read/29216584/differential-scanning-calorimetry-isothermal-hold-times-can-impact-interpretations-of-drug-polymer-dispersability-in-amorphous-solid-dispersions
#17
Kevin DeBoyace, Christine Zdaniewski, Peter L D Wildfong
Differential scanning calorimetry (DSC) is a commonly employed analytical technique for the analysis and characterization of amorphous solid dispersions. However, steps typical of standard temperature programs can alter the material in situ. Data for two active pharmaceutical ingredients are detailed, wherein isothermal hold times, traditionally employed to remove thermal history and/or residual solvent, were observed to impact the observed dispersability of the compounds in polyvinylpyrrolidone vinyl-acetate copolymer (PVPva)...
December 2, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/29209093/preparation-and-thermal-properties-of-mineral-supported-polyethylene-glycol-as-form-stable-composite-phase-change-materials-cpcms-used-in-asphalt-pavements
#18
Jiao Jin, Feipeng Lin, Ruohua Liu, Ting Xiao, Jianlong Zheng, Guoping Qian, Hongfu Liu, Pihua Wen
Three kinds of mineral-supported polyethylene glycol (PEG) as form-stable composite phase change materials (CPCMs) were prepared to choose the most suitable CPCMs in asphalt pavements for the problems of asphalt pavements rutting diseases and urban heat islands. The microstructure and chemical structure of CPCMs were characterized by SEM, FT-IR and XRD. Thermal properties of the CPCMs were determined by TG and DSC. The maximum PEG absorption of diatomite (DI), expanded perlite (EP) and expanded vermiculite (EVM) could reach 72%, 67% and 73...
December 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29206496/development-of-solid-dispersions-of-%C3%AE-lapachone-in-peg-and-pvp-by-solvent-evaporation-method
#19
K M Dos Santos, R M Barbosa, F G A Vargas, E P de Azevedo, A C S Lins, C A Câmara, C F S Aragão, T F Moura, F N Raffin
β-lapachone (βlap) has shown potential use in various medical applications. However, its poor solubility has limited its systemic administration and clinical applications. The aim of this work is to develop solid dispersions of βlap using poly (ethylene glycol) (PEG 6000) and polyvinylpyrrolidone (PVP K30) as hydrophilic polymers and evaluate the dissolution rate in aqueous medium. Solid dispersions were prepared by solvent evaporation method using different weight ratios of βlap and hydrophilic polymer (1:1, 1:2 and 1:3)...
December 5, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/29206126/a-combined-crystallographic-thermal-raman-and-computational-study-on-polymorphism-and-phase-transition-in-1-4-hexyloxy-3-hydroxyphenyl-ethanone
#20
Sebastián Suárez, Veronica E Manzano, Adolfo C Fantoni, Emilia Halac, Ricardo Baggio, Fabio D Cukiernik
The crystal structure of the triclinic polymorph of 1-(4-hexyloxy-3-hydroxyphenyl)ethanone, C14H20O3, differs markedly from that of the orthorhombic polymorph [Manzano et al. (2015). Acta Cryst. C71, 1022-1027]. The two molecular structures are alike with respect to their bond lengths and angles, but differ in their spatial arrangement. This gives rise to quite different packing schemes, even if built up by similar chains having the hydroxy-ethanone O-H...O hydrogen-bond synthon in common. Both phases were found to be related by a first-order thermally driven phase transformation at 338-340 K, which is discussed in detail...
December 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
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