scholarly journals In-Vitro Analysis of FeMn-Si Smart Biodegradable Alloy

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 568
Author(s):  
Ana Maria Roman ◽  
Victor Geantă ◽  
Ramona Cimpoeșu ◽  
Corneliu Munteanu ◽  
Nicoleta Monica Lohan ◽  
...  

Special materials are required in many applications to fulfill specific medical or industrial necessities. Biodegradable metallic materials present many attractive properties, especially mechanical ones correlated with good biocompatibility with vivant bodies. A biodegradable iron-based material was realized through electric arc-melting and induction furnace homogenization. The new chemical composition obtained presented a special property named SME (shape memory effect) based on the martensite transformation. Preliminary results about this special biodegradable material with a new chemical composition were realized for the chemical composition and structural and thermal characterization. Corrosion resistance was evaluated in Ringer’s solution through immersion tests for 1, 3, and 7 days, the solution pH was measured in time for 3 days with values for each minute, and electro-corrosion was measured using a potentiostat and a three electrode cell. The mass loss of the samples during immersion and electro-corrosion was evaluated and the surface condition was studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). SME was highlighted with differential scanning calorimetry (DSC). The results confirm the possibility of a memory effect of the materials in the wrought case and a generalized corrosion (Tafel and cyclic potentiometry and EIS) with the formation of iron oxides and a corrosion rate favorable for applications that require a longer implantation period.

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 182 ◽  
Author(s):  
Ng C. F. Grace ◽  
Christiani Jeyakumar Henry

Starches and flours used commonly in Asia (tapioca, sweet potato, sago, water chestnut, and high amylose maize starch, red rice and kithul flour) were characterized in terms of their chemical composition, morphological, functional, pasting, thermal, gelling and in vitro digestibility properties. It was observed that the differences in their chemical composition and structure influenced their properties. High amylose maize was the most stable, thus it required the highest gelatinization temperature which was observed in both the differential scanning calorimetry (DSC) and pasting profiles. Kithul flour had a significantly lower rate of digestion (p < 0.05) than the other samples (except for high amylose maize starch). Unlike high amylose maize starch, it had a gelatinization temperature that could be achieved during cooking, and had good gelling properties.


2012 ◽  
Vol 32 (1) ◽  
pp. 209-213 ◽  
Author(s):  
Marcelo Rodrigues Marques ◽  
Diego Damasceno Paz ◽  
Lívia Patrícia Rodrigues Batista ◽  
Celma de Oliveira Barbosa ◽  
Marcos Antônio Mota Araújo ◽  
...  

This study assessed the antioxidant, total phenolic, and physicochemical properties of in vitro Terminalia Catappa Linn (locally called castanhola) using the DPPH assay. The castanhola fruits had an average weight of 19.60 ± 0.00 g, combining shell, pulp, and seed weight, and a soluble solids content of 8 °Brix. The chemical composition was determined with predominance of carbohydrates (76,88 ± 0,58%).The titration method was used to determine Vitamin C content using 2,6-dichlorophenolindophenol (DCFI), known as reactive Tillmans resulting in no significant levels. Aqueous extracts of castanhola pulp showed a higher concentration of phenolics, 244.33 ± 18.86 GAE.g-1 of fruit, and alcoholic extracts, 142.84 ± 2.09 GAE.g-1 of fruit. EC50 values of the aqueous extract showed a greater ability to scavenge free radicals than the alcoholic extracts. The fruit had a significant content of phenolic compounds and high antioxidant capacity.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2678 ◽  
Author(s):  
Junyi Li ◽  
Caicai Zhao ◽  
Liping Wei ◽  
Xiang Li ◽  
Fuguo Liu ◽  
...  

In the current research, a new cichoric acid (CA) encapsulation system was investigated. The optimal condition for the formation of lactoferrin-cichoric acid nanoparticles (LF-CA NPs) was determined by controlling the solution pH, the thermal treatment conditions, and the concentration of CA. Fluorescence indicated that the electrostatic force and the hydrophobic force were the main forces in the formation of LF-CA NPs. LF-CA NPs prepared under different conditions were spherical in shape with smaller particle sizes and good zeta potential demonstrating good colloidal stability. Especially, the prepared particle size of the LF-CA NPs at pH 7 and 95 °C was about 67.20 ± 1.86 nm. The circular dichroism (CD) and the Fourier transform infrared spectroscopy (FTIR) results showed that the combination of LF (lactoferrin) and CA affected the secondary structure of the LF. The differential scanning calorimetry (DSC) results indicated that the addition of CA increased the thermal stability of LF. In vitro antioxidant experiments confirmed the antioxidant capacity of LF-CA NPs was better than CA. CA was successfully encapsulated into LF NPs with high encapsulated efficiency (97.87–99.87%) by high performance liquid chromatography (HPLC). These results showed that LF could be used as the wall material of CA with excellent nature.


2022 ◽  
Author(s):  
James Todd Hoopes ◽  
Ryan D. Heselpoth ◽  
Frederick P. Schwarz ◽  
Daniel C Nelson

Bacteriophage endolysins degrade the bacterial peptidoglycan and are considered enzymatic alternatives to small molecule antibiotics. In particular, the multimeric streptococcal endolysin PlyC has appealing antibacterial properties. However, a comprehensive thermal analysis of PlyC is lacking, which is necessary for evaluating long-term stability and downstream therapeutic potential. Biochemical and kinetic-based methods were used in combination with differential scanning calorimetry to investigate the structural, kinetic and thermodynamic stability of PlyC and its various subunits and domains. The PlyC holoenzyme structure is irreversibly compromised due to partial unfolding and aggregation at 46°C. Unfolding of the catalytic subunit, PlyCA, instigates this event, resulting in the kinetic inactivation of the endolysin. In contrast to PlyCA, the PlyCB octamer (the cell wall binding domain) is thermostable, denaturing at ~75°C. Isolation of PlyCA or PlyCB alone altered their thermal properties. Contrary to the holoenzyme, PlyCA alone unfolds uncooperatively and is thermodynamically destabilized whereas the PlyCB octamer reversibly dissociates into monomers and forms an intermediate state at 74°C in phosphate buffered saline, with each subunit subsequently denaturing at 927°C. Adding folded PlyCA to an intermediate state PlyCB, followed by cooling, allowed for in vitro reconstitution of the active holoenzyme.


2019 ◽  
Vol 27 (3) ◽  
pp. 300-306 ◽  
Author(s):  
V. A. Palchykov ◽  
V. V. Zazharskyi ◽  
V. V. Brygadyrenko ◽  
P. O. Davydenko ◽  
O. M. Kulishenko ◽  
...  

We have studied the chemical composition and antibacterial profile of ethanolic extract of Punica granatum L. (Lythraceae) on strains of microorganisms in vitro. Analysis using GC-MS showed 5-hydroxymethylfurfural (36.6%), D-sucrose (23.2%), sorbitol (6.7%), palmitic acid β-monoglyceride (5.6%), 2-furancarboxaldehyde (3.5%) and β-D-glucopyranose (3.3%) as the major components of the title extract. The experiment revealed a positive antibacterial effect of extracts obtained from P. granatum on 14 strains specifically Enterobacteriaceae microorganisms (Escherichia coli, Enterobacter aegorenеs, Proteus vulgaris, Serratia marcescens, Klebsiella pneumonia), Listeriaceae (Listeria ivanovi, L. іnnocua, L. monocytogenes) and yeasts from the family Saccharomycetaceae (Candida albicans). Our study showed that in many cases these extracts more intensively affect multi-resistant strains of microorganisms than macrolide antibiotic azithromycin and is therefore a source of molecules to be exploited in medicine or by the pharmaceutical industry. The investigated extracts of P. granatum can be recommended for further in-depth research against poly-resistant strains of the above-mentioned microorganisms. Effective drugs perform a leading role in providing stable veterinary well-being of livestock and healthcare of the population. The present study showed that the studied plant species more intensively affects multi-resistant strains of microorganisms than sodium salt of azithromycin. Lethal concentration (LC50) of ethanol extract from pomegranate for Paramecium caudatum Ehr. equaled 0.3%. Death of 100% of nematode larvae of Strongyloides papillosus (Ihle) was recorded during 24 h exposition in 20% extract of P. granatum peel.


2018 ◽  
Vol 21 (2) ◽  
pp. 164
Author(s):  
Rodrigo Furtado De Carvalho ◽  
Fernando Luiz Goulart Cruz ◽  
Debora Pinto Antunes ◽  
Evane Gonçalves Toledo Júnior ◽  
Luiz Fernando Cappa De Oliveira ◽  
...  

<p><strong>Objective</strong>: This study compared the radiopacity of different ceramic systems by means of digital radiographs and evaluate the chemical composition of the samples by Raman spectroscopy. <strong>Material and Methods</strong>: The hypothesis tested was that there was a difference in radiopacity among the tested materials. Specimens were prepared for each ceramic tested: FLD - VM7 (VITA Zahnfabrik), LD - IPS Empress e.max Press (IPS Empress), AL - In Ceram Alumina (VITA Zahnfabrik), ALYZ - In Ceram Zirconia (VITA Zahnfabrik), YZ - Lava All Ceram (3M/ESPE), and MYZ - Zirconzahn (Talladium Brazil). The specimens were radiographed and submitted to radiographic density readings using a histogram tool. The spectrometer coupled to a petrographic microscope was used for Raman spectroscopy measurements. Analysis of variance (ANOVA) and a Tukey post-hoc test were used to compare radiopacity of the different materials. <strong>Results</strong>: For all tested materials, the radiopacity showed statistically significant differences, except YZ and MYZ. Lava All Ceram and ZirkonZahn had high radiopacity values and VM7 and IPS Empress e.max Press showed lower radiopacity than human dental structures. <strong>Conclusion</strong>: It was possible to conclude that radiopacity is closely linked to ceramic chemical composition.</p><p><strong>Keywords</strong></p><p>Dental ceramics; Radiopacity; Raman spectroscopy test; Restorative dentistry.</p>


Author(s):  
R.A. Milligan ◽  
P.N.T. Unwin

A detailed understanding of the mechanism of protein synthesis will ultimately depend on knowledge of the native structure of the ribosome. Towards this end we have investigated the low resolution structure of the eukaryotic ribosome embedded in frozen buffer, making use of a system in which the ribosomes crystallize naturally.The ribosomes in the cells of early chicken embryos form crystalline arrays when the embryos are cooled at 4°C. We have developed methods to isolate the stable unit of these arrays, the ribosome tetramer, and have determined conditions for the growth of two-dimensional crystals in vitro, Analysis of the proteins in the crystals by 2-D gel electrophoresis demonstrates the presence of all ribosomal proteins normally found in polysomes. There are in addition, four proteins which may facilitate crystallization. The crystals are built from two oppositely facing P4 layers and the predominant crystal form, accounting for >80% of the crystals, has the tetragonal space group P4212, X-ray diffraction of crystal pellets demonstrates that crystalline order extends to ~ 60Å.


2005 ◽  
Vol 173 (4S) ◽  
pp. 315-316
Author(s):  
Kari Hendlin ◽  
Brynn Lund ◽  
Manoj Monga

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