scholarly journals Effect of Drying Temperature on the Magnetic and Microstructural Properties of BaFe12O19 Synthesized by Coprecipitation Method

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mamman Nur Sanda ◽  
Mohsen Hakimi ◽  
Mohamad Reza Samadzadeh Yazdi ◽  
Hanieh Karimi
Keyword(s):  
Drug Delivery Systems ◽  
Barium Hexaferrite ◽  
Coprecipitation Method ◽  
High Coercivity ◽  
Time Interval ◽  
Microstructural Properties ◽  
Electric Motors ◽  
Drying Temperature ◽  
Factors Influencing ◽  
Different Temperatures

Barium hexaferrite (BaFe12O19) has dominated many aspects of technology, serving as a permanent magnet, magnetoelectric, multiferroic, and electric motors, generators, microwave devices, and drug delivery systems. There is a challenge in the synthesis of BaFe12O19 with the coprecipitation method. As a result, research is conducted to examine the factors influencing the properties of BaFe12O19 during the preparation process, specifically on the drying temperature of the mixture. The precursors were precipitated, through some procedural steps, along with stirring at 450 rpm at a certain temperature for a while and simultaneously pouring the precipitant dropwise; the sample was dried at different temperatures. The final samples were annealed at the same rate of temperature within the same time interval. The results depicted that drying at different temperatures leads to the variation in the magnetic and microstructural properties of BaFe12O19, indicating that drying at high temperatures resulted in high coercivity with low saturated magnetization.

Biosurfactants as a Novel Additive in Pharmaceutical Formulations: Current Trends and Future Implications

2020 ◽  
Vol 21 (11) ◽  
pp. 885-901
Author(s):  
Shubham Thakur ◽  
Amrinder Singh ◽  
Ritika Sharma ◽  
Rohan Aurora ◽  
Subheet Kumar Jain
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Toxicity Testing ◽  
Pharmaceutical Formulations ◽  
Delivery Systems ◽  
Surface Active Agents ◽  
Regulatory Status ◽  
Different Temperatures ◽  
High Production Cost ◽  
New Generation

Background: Surfactants are an important category of additives that are used widely in most of the formulations as solubilizers, stabilizers, and emulsifiers. Current drug delivery systems comprise of numerous synthetic surfactants (such as Cremophor EL, polysorbate 80, Transcutol-P), which are associated with several side effects though used in many formulations. Therefore, to attenuate the problems associated with conventional surfactants, a new generation of surface-active agents is obtained from the metabolites of fungi, yeast, and bacteria, which are termed as biosurfactants. Objectives: In this article, we critically analyze the different types of biosurfactants, their origin along with their chemical and physical properties, advantages, drawbacks, regulatory status, and detailed pharmaceutical applications. Methods: 243 papers were reviewed and included in this review. Results: Briefly, Biosurfactants are classified as glycolipids, rhamnolipids, sophorolipids, trehalolipids, surfactin, lipopeptides & lipoproteins, lichenysin, fatty acids, phospholipids, and polymeric biosurfactants. These are amphiphilic biomolecules with lipophilic and hydrophilic ends and are used as drug delivery vehicles (foaming, solubilizer, detergent, and emulsifier) in the pharmaceutical industry. Despite additives, they have some biological activity as well (anti-cancer, anti-viral, anti-microbial, P-gp inhibition, etc.). These biomolecules possess better safety profiles and are biocompatible, biodegradable, and specific at different temperatures. Conclusion: Biosurfactants exhibit good biomedicine and additive properties that can be used in developing novel drug delivery systems. However, more research should be driven due to the lack of comprehensive toxicity testing and high production cost which limits their use.

scholarly journals The effect of drying temperature on the properties of gelatin from carps (Cyprinus carpio) skin

2019 ◽  
Vol 37 (No. 4) ◽  
pp. 246-251 ◽  
Author(s):  
Joanna Tkaczewska ◽  
Maciej Wielgosz ◽  
Piotr Kulawik ◽  
Marzena Zajac
Keyword(s):  
Cyprinus Carpio ◽  
Freeze Drying ◽  
Treatment Method ◽  
Thermal Hydrolysis ◽  
Gel Properties ◽  
Drying Temperature ◽  
Freeze Dried ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Hydrolysis Of

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The  electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by thermal hydrolysis of collagen fibrils. Freeze drying is the only effective method for drying this product, which can be used in industry.

scholarly journals Environmental and biological factors influencing trace elemental and microstructural properties of Arctica islandica shells

2018 ◽  
Vol 645 ◽  
pp. 913-923 ◽  
Author(s):  
Irene Ballesta-Artero ◽  
Liqiang Zhao ◽  
Stefania Milano ◽  
Regina Mertz-Kraus ◽  
Bernd R. Schöne ◽  
...  
Keyword(s):  
Microstructural Properties ◽  
Biological Factors ◽  
Arctica Islandica ◽  
Factors Influencing ◽  
Trace Elemental

scholarly journals Effects of drying temperature on quality parameters of Thai fermented fish dip (Jaew Bong)

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Pongdanai Duangsai ◽  
Somsamorn Gawborisut
Keyword(s):  
Colour Change ◽  
Quality Parameters ◽  
Plate Count ◽  
Fermented Fish ◽  
Drying Temperature ◽  
Total Plate Count ◽  
Different Temperatures ◽  
L Value ◽  
Mold Count ◽  
Better Than

Fermented fish dip is a popular condiment in Thailand and the Lao People’s Democratic Republic. Thai fermented fish dip (TFFD), can be dried to increase its shelf life and ease of transportation. Dried TFFD can be rehydrated to return the powder to its original, paste-like form. Pre-cooked TFFD paste was dried at three different temperatures (40, 60, and 80 ºC). Total plate count, yeast and mold count, CIE colour values (L*, a*, and b*),non-enzymatic browning, and sensory scores of the resulting powders were determined. The CIE colour values and sensory scores were alsoanalysed for rehydrated TFFD. Increasing the drying temperature did not affect the total plate count or yeast and mold count. When dried at 80 ºC, the L* value of TFFD powder was reduced, although the a* and b* values were unaffected compared with lower temperatures. All CIE colour values of rehydrated TFFD decreased as drying temperature increased. Drying temperature did not affect the sensory scores of dried TFFD powder. However, rehydrated samples that had been dried at 80 ºC had significantly lower sensory colour scores than those dried at 40 or 60 ºC. Overall preference rankings of dried and rehydrated TFFD dried at 40 and 60 °C were better than for those dried at 80 °C. Due to an undesirable colour change in the rehydrated product, 80 ºC was deemed to be an unsuitable temperature for drying TFFD paste. In conclusion, both 40 and 60 ºC are appropriate temperatures for drying the product.

scholarly journals Identification of factors influencing insertion characteristics of cochlear implant electrode carriers

2019 ◽  
Vol 5 (1) ◽  
pp. 441-443
Author(s):  
Silke Hügl ◽  
Nina Aldag ◽  
Thomas Lenarz ◽  
Thomas S. Rau ◽  
Alexander Becker ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Test Bench ◽  
Time Interval ◽  
Dynamic Force ◽  
Friction Forces ◽  
Factors Influencing ◽  
Constant Diameter ◽  
Constant Radius ◽  
Force Components ◽  
Insertion Process

AbstractInsertion studies in artificial cochlea models (aCM) are used for the analysis of insertion characteristics of different cochlear implant electrode carrier (EC) designs by measuring insertion forces. These forces are summed forces due to the measuring position which is directly underneath the aCM. The current hypothesis is that they include dynamic friction forces during the insertion process and the forces needed to bend an initially straight EC into the curved form of the aCM. For the purposes of the present study, straight EC substitutes with a constant diameter of 0.7 mm and 20.5 mm intracochlear length were fabricated out of silicone in two versions with different stiffness by varying the number of embedded wires. The EC substitutes were inserted into three different models made of polytetrafluoroethylene (PTFE), each model showing only one constant radius. Three different insertion speeds were used (0.11 / 0.4 / 1.6 mm/s) with an automated insertion test bench. For each parameter combination (curvature, speed, stiffness) twelve insertions were conducted. Measurements included six full insertions and six paused insertions. Paused insertions include a ten second paused time interval without further insertion movement each five millimetres. Measurements showed that dynamic and static components of the measured summed forces can be identified. Dynamic force components increase with increased insertion speeds and also with increased stiffness of the EC substitutes. Both force components decrease with larger radius of the PTFE model. After the insertion, the EC substitutes showed a curved shape, which indicates a plastic deformation of the embedded wires due to the insertion into the curved models. The results can be used for further research on an analytical model to predict the insertions forces of a specific combination of selected parameters as insertion speed and type of EC, combined with given factors such as cochlear geometry.

Low-Temperature Short-Time SPS Processes to Produce Fine-Grained High-Coercivity Barium Hexaferrite Ceramics from Polyol Nanoparticles

2017 ◽  
Vol 31 (2) ◽  
pp. 347-351 ◽  
Author(s):  
G. Vázquez-Victorio ◽  
N. Flores-Martínez ◽  
G. Franceschin ◽  
S. Nowak ◽  
S. Ammar ◽  
...  
Keyword(s):  
Low Temperature ◽  
Barium Hexaferrite ◽  
High Coercivity ◽  
Fine Grained ◽  
Short Time

A Comparative Study on the Morphology and Magnetic Properties of Barium and Strontium Hexaferrite Nanoparticles Synthesized by Co-Precipitation Method

2009 ◽  
Vol 67 ◽  
pp. 203-208 ◽  
Author(s):  
Sachin Tyagi ◽  
Ramesh Chandra Agarwala ◽  
Vijaya Agarwala
Keyword(s):  
Ultrafine Particles ◽  
Barium Hexaferrite ◽  
Nitrogen Atmosphere ◽  
Precipitation Method ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Heat Treated ◽  
Different Temperatures ◽  
Co Precipitation ◽  
Decomposition Behaviour

Nanocrystalline strontium hexaferrite (SrFe12O19) and barium hexaferrite (BaFe12O19) powders were synthesized by co-precipitation method. The ‘as synthesized’ powders were heat treated (HT) at different temperatures ranging from 800 to 1200°C at a heating rate of 30°C /min in nitrogen atmosphere. Decomposition behaviour and the phases associated therein are investigated by thermal analysis (DTA/DTG/TG) and X-ray diffraction (XRD). Formations of ultrafine particles have been confirmed through field emission scanning electron microscop (FESEM). The superparamagnetic behavior of both, barium and strontium hexaferrite is confirmed by vibrating sample magnetometer (VSM). The increase in saturation magnetization from 1.94 to 31.05 emu/gm in case of barium hexaferrite and from 2.44 to 43.38 emu/gm for strontium hexaferrite is observed with HT temperatures. The changes in coercivity and remanence with HT temperatures for both the ferrites are analysed.

Use of First or Second Generation TKI for CML after Allogeneic Stem Cell Transplantation: a Study By the CMWP of the EBMT

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4685-4685 ◽  
Author(s):  
Yves Chalandon ◽  
Simona Iacobelli ◽  
Jennifer Hoek ◽  
Linda Koster ◽  
Liisa Volin ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Research Funding ◽  
Chronic Phase ◽  
Time Interval ◽  
Hematopoietic Stem ◽  
Persistent Disease ◽  
Factors Influencing

Abstract Background: Patients (pts) relapsing with CML after allogeneic hematopoietic stem cell transplantation (alloHSCT) may be treated with tyrosine kinase inhibitors (TKI) and/or donor lymphocyte infusions (DLI). As nowadays the majority of CML patients would have received at least imatinib prior to transplantation, we were interested in analizing a) the type of TKI used after alloHSCT, b) the indication for TKI treatment, c) the outcome of this treatment and d) the temporal relationship with DLI if given. Patients and methods: 435 pts received TKI after first allogeneic HSCT for CML for different reasons. Transplants had been performed in first chronic phase (CP1, n=194), accelerated phase (AP, n= 60) or for more advanced disease (blast crisis (BC)/> CP1, n=177) from HLA identical siblings (n=231) or unrelated donors (n=204) between 2000 and 2013. TKI given prior to transplant was imatinib (n=268), dasatinib (n=162), nilotinib (n=88), bosutinib (n=4) and ponatinib (n=7). Median age at transplant was 44 (18.5-68) years, 274 pts (63%) were male. TKI post alloHSCT were given between 2000 and 2015. 1st TKI given was either imatinib (n=223), dasatinib (n=131), nilotinib (n=67), bosutinib (n=2) or ponatinib (12). The indications for TKI therapy were the same as for transplantation (n=262), for relapse/progression/persistent disease (n=124), for prophylaxis/pre-emptive (n=32), planned (n=5), others (n=8) and missing (n=4). Results: Median follow-up from start of TKI was 55 (1-171) months. The median time interval from transplant to TKI was 6 (0.2-165) months. It was longer for TKI given for relapse/progression with 15 (1-89) months and shorter for TKI given for prophylaxis/pre-emptive with 1.6 (0.2-43) months. It was longer for imatinib with 11 (0.2-121) months vs 3.8 (0.2-165) months for other TKI. Imatinib as 1st TKI was mainly given for relapse/progression/persistent disease (48%) and the other TKI for the same reason as for transplantation (83%). 103/223 (46%) of pts with imatinib, 99/131 (76%) with dasatinib, 55/67 (82%) with nilotinib and 11/14 (79%) with bosutinib/ponatinib post-transplantation had been treated with imatinib prior to transplantation. In total, 196 (45%) patients received DLI after alloHSCT, of which 63/435 (14.5%) had DLI prior to TKI post-alloHSCT, 19/435 (4.4%) had DLI at the same time of TKI and 114/435 (26%) had DLI post-TKI. Best response after TKI was complete molecular remission in 17.7%, cytogenetic remission in 4.4%, hematological remission in 20.2% and no response/progression/relapse in 57.7% of pts. 50% of pts treated with imatinib had a response (molecular/cytogenetic/hematological) vs 34% with nilotinib, 33% with dasatinib and 33% with bosutinib/ponatinib, p=0.014. OS was 60% (55-65%) at 5 years. It was 66% (60-73%) with imatinib vs 51% (42-60%) with other TKI, p=0.0024. 5 years RFS was 47% (42-53%). It was 53% (46-60%) with imatinib vs 40% (32-48%) with other TKI, p=0.0102. 5 years RI was 25% (21-30%). It was 21% (16-27%) with imatinib vs 31% (24-38%) with other TKI, p=0.0454. 5 years NRM was 27% (23-32%). It was 26% (20-31%) with imatinib vs 29% (22-36%) with other TKI, p=0.365. In multivariate analysis for OS, imatinib vs other TKI post-transplant did not show anymore an effect, HR 1.19 (0.85-1.67), p=0.317. Factors influencing OS were time from diagnosis to transplant, HR 1.01 (1.00-1.01), p=0.009, AP vs CP1, HR 1.80 (1.11-2.91), p=0.017 and BC/>CP1 vs CP1, HR 2.3 (1.58-3.33), p<0.0001. In multivariate analysis for RFS as for OS, imatinib vs other TKI did not have an effect, HR 1.11 (0.83-1.48), p=0.496. Other factors having a tendency or influencing RFS were time from diagnosis to transplant, HR 1.00 (1.00-1.01), p=0.054, AP vs CP1, HR 1.52 (1.00-2.31), p=0.050 and BC/>CP1 vs CP1, HR 2.11 (1.55-2.88), p<0.001. Conclusion: These data suggest that TKI after alloHSCT induce a response in about 42% of pts regardless of the type of TKI used and that time from diagnosis to transplantation as well as the phase of disease at transplant remain the main factors influencing the outcome of CML patients relapsing after alloHSCT. Disclosures Kröger: Riemser: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Neovii: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding.

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