scholarly journals Thymoquinoneβ-Cyclodextrin Nanoparticles System: A Preliminary Study

2012 ◽  
Vol 27 ◽  
pp. 329-336 ◽  
Author(s):  
T. Cardoso ◽  
C. I. C. Galhano ◽  
M. F. Ferreira Marques ◽  
A. Moreira da Silva
Keyword(s):  
Inclusion Compound ◽  
Nigella Sativa ◽  
Pharmaceutical Formulations ◽  
Anticancer Activities ◽  
Scanning Calorimetry ◽  
Positron Annihilation Lifetime ◽  
Dsc Measurements ◽  
System A ◽  
Preliminary Study ◽  
Calorimetric Studies

Thymoquinone is a natural product, the main constituent ofNigella sativaseeds, which exhibits anti-inflammatory and anticancer activities. Among several existing molecules capable of forming an inclusion compound structure, cyclodextrins are applied in the pharmaceutical industry either to increase solubility of hydrophobic molecules or to protect molecules from inactivation or degradation.β-Cyclodextrin is currently the most common cyclodextrin in pharmaceutical formulations and probably the best studied in humans. In order to study the properties of inclusion compounds based on cyclodextrins and thymoquinone Fourier Transform Infrared (FTIR), Ultraviolet-Visible, Positron Annihilation Lifetime (PAL) Spectroscopies and calorimetric studies by Differential Scanning Calorimetry (DSC) were used. The obtained results indicate the formation of a 1 : 1 inclusion compound between cyclodextrin and thymoquinone. PALS and DSC measurements also provided evidence of the inclusion compound's activity.

PALS and DSC measurements in 8 MeV electron irradiated natural rubber filled with different fillers

2015 ◽  
Vol 29 (28) ◽  
pp. 1550196
Author(s):  
Arunava Mandal ◽  
Sandip Pan ◽  
Anirban Roychowdhury ◽  
Asmita Sengupta
Keyword(s):  
Natural Rubber ◽  
Specific Heat ◽  
Free Volume ◽  
Positron Lifetime ◽  
High Energy ◽  
High Energy Electron ◽  
Scanning Calorimetry ◽  
Positron Annihilation Lifetime ◽  
Dsc Measurements ◽  
Volume Size

The effect of high energy electron irradiation on the microstructure and thermal properties of natural rubber (NR) filled with different fillers at different concentrations are studied. The samples are irradiated with 8 MeV electron beam to a total dose of 100 KGy. The change in free volume size and specific heat due to addition of fillers and irradiation are studied using positron annihilation lifetime spectroscopy (PALS) and differential scanning calorimetry (DSC) respectively. The Positron lifetime spectra are de-convoluted into two components. The longer lived component [Formula: see text] signifies the pick-off annihilation of ortho-positronium (o-Ps) at free volume site which may be related to the radius of the free volume holes. It is observed that the specific heat [Formula: see text] and free volume size are all affected by both irradiation and addition of fillers.

Development and Certification of Formononetin Reference Material for Quality Control of Functional Foods and Botanical Supplements

2019 ◽  
Vol 15 (5) ◽  
pp. 553-559
Author(s):  
Ningbo Gong ◽  
Baoxi Zhang ◽  
Kun Hu ◽  
Zhaolin Gao ◽  
Guanhua Du ◽  
...  
Keyword(s):  
Quality Control ◽  
Reference Material ◽  
Functional Foods ◽  
Certified Reference Materials ◽  
Coulometric Titration ◽  
Pharmaceutical Formulations ◽  
Uncertainty Estimation ◽  
Expanded Uncertainty ◽  
Scanning Calorimetry ◽  
Botanical Supplements

Background: Formononetin is a common soy isoflavonoid that can be found abundantly in many natural plants. Previous studies have shown that formononetin possesses a variety of activities which can be applied for various medicinal purposes. Certified Reference Materials (CRMs) play a fundamental role in the food, traditional medicine and dietary supplement fields, and can be used for method validation, uncertainty estimation, as well as quality control. Methods: The purity of formononetin was determined by Differential Scanning Calorimetry (DSC), Coulometric Titration (CT) and Mass Balance (MB) methods. Results: This paper reports the sample preparation methodology, homogeneity and stability studies, value assignment, and uncertainty estimation of a new certified reference material of formononetin. DSC, CT and MB methods proved to be sufficiently reliable and accurate for the certification purpose. The purity of the formononetin CRM was therefore found to be 99.40% ± 0.24 % (k = 2) based on the combined value assignments and the expanded uncertainty. Conclusion: This CRM will be a reliable standard for the validation of the analytical methods and for quality assurance/quality control of formononetin and formononetin-related traditional herbs, food products, dietary supplements and pharmaceutical formulations.

scholarly journals Polypropylene/Lignin/POSS Nanocomposites: Thermal and Wettability Properties, Application in Water Remediation

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3950
Author(s):  
Abeer Alassod ◽  
Syed Rashedul Islam ◽  
Mina Shahriari Khalaji ◽  
Rogers Tusiime ◽  
Wanzhen Huang ◽  
...  
Keyword(s):  
Organic Liquid ◽  
Contact Angles ◽  
Water Remediation ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Thermally Induced ◽  
Dsc Measurements ◽  
Infrared Measurement ◽  
Oligomeric Silsesquioxane ◽  
Tga And Dsc

Compositing is an interesting strategy that has always been employed to introduce or enhance desired functionalities in material systems. In this paper, sponges containing polypropylene, lignin, and octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) were successfully prepared via an easy and elegant strategy called thermally induced phase separation (TIPS). To fully explore the behaviour of different components of prepared sponges, properties were characterized by a thermogravimetric analyser (TGA), differential scanning calorimetry (DSC), Fourier transform infrared measurement (FTIR), and scanning electron microscopy (SEM). Furthermore, wettability properties toward an organic liquid and oil were investigated. The FTIR analysis confirmed the chemical modification of the components. TGA and DSC measurements revealed thermal stability was much better with an increase in OV-POSS content. OV-POSS modified sponges exhibited ultra-hydrophobicity and high oleophilicity with water contact angles of more than 125°. The SEM revealed that POSS molecules acted as a support for reduced surface roughness. Moreover, OV-POSS-based blend sponges showed higher sorption capacities compared with other blend sponges without OV-POSS. The new blend sponges demonstrated a potential for use as sorbent engineering materials in water remediation.

scholarly journals Ultrasound-guided transvaginal radiofrequency ablation of uterine fibroids assisted by virtual needle tracking system: a preliminary study

2018 ◽  
Vol 35 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Giovanni Turtulici ◽  
Davide Orlandi ◽  
Giorgia Dedone ◽  
Giovanni Mauri ◽  
Alessandro Fasciani ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Tracking System ◽  
Uterine Fibroids ◽  
Ultrasound Guided ◽  
System A ◽  
Preliminary Study

Spasticity Measurement Based on the HHT Marginal Spectrum Entropy of sEMG Using a Portable System: A Preliminary Study

2018 ◽  
Vol 26 (7) ◽  
pp. 1424-1434 ◽  
Author(s):  
Baohua Hu ◽  
Xiufeng Zhang ◽  
Jingsong Mu ◽  
Ming Wu ◽  
Zongjun Zhu ◽  
...  
Keyword(s):  
System A ◽  
Marginal Spectrum ◽  
Portable System ◽  
Preliminary Study

Investigations on the polymorphism and pseudopolymorphism of clobetasone butyrate

2011 ◽  
Vol 76 (5) ◽  
pp. 553-566
Author(s):  
Christian Näther ◽  
Inke Jeß
Keyword(s):  
Room Temperature ◽  
Polymorphic Form ◽  
Stable Form ◽  
Scanning Calorimetry ◽  
Amorphous Form ◽  
Space Group ◽  
Dsc Measurements ◽  
Independent Molecules ◽  
Solvent Molecules ◽  
Similar Conformation

Clobetasone butyrate was investigated for polymorphism and pseudopolymorphism. Solvent mediated conversion experiments reveal that the commercially available form I represent the thermodynamically most stable form at room temperature and DSC measurements shows that it should also be the most stable form until melting. Form I crystallizes in space groupP212121with three crystallographically independent molecules of similar conformation. From methanol an additional pseudo polymorphic form was discovered. In the crystal structure (space groupP212121) the solvent molecules are connected to the clobetasone butyrate molecules by O–H···O hydrogen bonding. Investigations of the solvate using thermogravimetry, differential thermoanalysis as well as differential scanning calorimetry proves, that on solvent removal an amorphous form is obtained that crystallizes into form I on further heating.

Effects of Aging on the Microstructure and Phase Transformation Behavior of Cu-Al-Mn Shape Memory Alloy

2021 ◽  
Vol 882 ◽  
pp. 21-27
Author(s):  
Seyed Veghar Seyedmohammadi ◽  
Amin Radi ◽  
Guney Guven Yapici
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Aging Treatment ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Peak Aged Condition ◽  
Peak Aged ◽  
Rolled Condition ◽  
The One ◽  
Effects Of Aging

In the present work, the effects of artificial aging treatment on the transformation temperatures and hardness of Cu-Al-Mn shape memory alloy have been investigated. The aging processes have been performed on the one-time re-melted and 90% rolled samples. Differential scanning calorimetry reveals that reverse transformation is present for the re-melted sample which is aged at 400°C. However, in 90% rolled condition, this transformation takes place at 200°C and 300°C. Hardness examination shows that the aged specimens possess higher values in hardness in comparison to un-aged samples at all studied temperatures. Although, the peak-aged condition was demonstrated at 300°C for the re-melted sample, the rolled sample displayed increased hardness levels up to 500°C. Based on the DSC measurements and microstructural observations, it can be asserted that the thermo-mechanical processing including rolling plus aging at 300°C provides favorable transformation characteristics for shape memory behavior.

Direct radioimmunoassay of 6-sulfatoxymelatonin in plasma with use of an iodinated tracer

1991 ◽  
Vol 37 (4) ◽  
pp. 536-539 ◽  
Author(s):  
Catherine Harthé ◽  
Bruno Claustrat ◽  
Jocelyne Brun ◽  
Guy Chazot
Keyword(s):  
Plasma Sample ◽  
Limit Of Detection ◽  
Circadian Variation ◽  
Hepatic Metabolism ◽  
Pharmaceutical Formulations ◽  
Practical Application ◽  
Bovine Serum Albumin Conjugate ◽  
Preliminary Study ◽  
Related Compounds

Abstract We describe here a direct a radioimmunoassay (RIA) for the determination of 6-sulfatoxymelatonin (aMT6s) in plasma, with iodinated aMT6s as tracer. The aMT6s antiserum was raised in rabbit by immunization with a bovine serum albumin conjugate, giving negligible cross-reactivities for related compounds. The low limit of detection (15 pmol/L) allowed a direct assay that required only a 100-microL plasma sample. Dilutions of plasma and of synthetic aMT6s gave the same parallel response in the RIA. A preliminary study showed a circadian variation in healthy volunteers, with mean concentrations ranging from 52 (at 1600-2100 h) to 378 pmol/L (at 0400 h), whereas this rhythm was abolished in pinealomectomized patients. After administration of melatonin orally, or by infusion, the aMT6s concentrations in plasma concorded with previous data on aMT6s production and pharmacokinetics, with aMT6s being cleared from plasma more slowly than melatonin. This assay should have practical application in the development of new pharmaceutical formulations that minimize the hepatic metabolism of melatonin.

scholarly journals A Facile Synthesis and Characterization of Highly Crystalline Submicro-Sized BiFeO3

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3035
Author(s):  
Dovydas Karoblis ◽  
Diana Griesiute ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
Dmitry V. Karpinsky ◽  
...  
Keyword(s):  
Bismuth Ferrite ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Synthetic Approach ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Optimal Annealing Temperature ◽  
Synthesized Materials

In this study, a highly crystalline bismuth ferrite (BFO) powder was synthesized using a novel, very simple, and cost-effective synthetic approach. It was demonstrated that the optimal annealing temperature for the preparation of highly-pure BFO is 650 °C. At lower or higher temperatures, the formation of neighboring crystal phases was observed. The thermal behavior of BFO precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis and Mössbauer spectroscopy were employed for the investigation of structural properties. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials. The obtained powders were also characterized by magnetization measurements, which showed antiferromagnetic behavior of BFO powders.

Sign in / Sign up

Export Citation Format

Share Document