scholarly journals Implant materials modified by colloids

2016 ◽  
Vol 34 (1) ◽  
pp. 33-37
Author(s):  
Beata Zboromirska-Wnukiewicz ◽  
Witold Wnukiewicz ◽  
Krzysztof Kogut ◽  
Jan Wnukiewicz ◽  
Roman Rutowski ◽  
...  
Keyword(s):  
General Medicine ◽  
Electrical Strength ◽  
Fluid Interface ◽  
Chemical Route ◽  
Electrical Method ◽  
Clinical Observations ◽  
Modified Surface ◽  
Electrical Methods ◽  
Skeletal Reconstruction

AbstractRecent advances in general medicine led to the development of biomaterials. Implant material should be characterized by a high biocompatibility to the tissue and appropriate functionality, i.e. to have high mechanical and electrical strength and be stable in an electrolyte environment – these are the most important properties of bioceramic materials. Considerations of biomaterials design embrace also electrical properties occurring on the implant-body fluid interface and consequently the electrokinetic potential, which can be altered by modifying the surface of the implant. In this work, the surface of the implants was modified to decrease the risk of infection by using metal colloids. Nanocolloids were obtained using different chemical and electrical methods. It was found that the colloids obtained by physical and electrical methods are more stable than colloids obtained by chemical route. In this work the surface of modified corundum implants was investigated. The implant modified by nanosilver, obtained by electrical method was selected. The in vivo research on animals was carried out. Clinical observations showed that the implants with modified surface could be applied to wounds caused by atherosclerotic skeleton, for curing the chronic and bacterial inflammations as well as for skeletal reconstruction surgery.

scholarly journals Synergistic Effect Induced by Gold Nanoparticles with Polyphenols Shell during Thermal Therapy: Macrophage Inflammatory Response and Cancer Cell Death Assessment

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3610
Author(s):  
Valeria De Matteis ◽  
Mariafrancesca Cascione ◽  
Loris Rizzello ◽  
Daniela Erminia Manno ◽  
Claudia Di Guglielmo ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Calcium Release ◽  
Chemical Properties ◽  
Chemical Route ◽  
Au Nps ◽  
Anticancer Properties ◽  
Cancer Cell Death ◽  
Combined Strategy

Background: In recent decades, gold nanoparticle (Au NP)-based cancer therapy has been heavily debated. The physico-chemical properties of AuNPs can be exploited in photothermal therapy, making them a powerful tool for selectively killing cancer cells. However, the synthetic side products and capping agents often induce a strong activation of the inflammatory pathways of macrophages, thus limiting their further applications in vivo. Methods: Here, we described a green method to obtain stable polyphenol-capped AuNPs (Au NPs@polyphenols), as polyphenols are known for their anti-inflammatory and anticancer properties. These NPs were used in human macrophages to test key inflammation-related markers, such as NF-κB, TNF-α, and interleukins-6 and 8. The results were compared with similar NPs obtained by a traditional chemical route (without the polyphenol coating), proving the potential of Au NPs@polyphenols to strongly promote the shutdown of inflammation. This was useful in developing them for use as heat-synergized tools in the thermal treatment of two types of cancer cells, namely, breast cancer (MCF-7) and neuroblastoma (SH-SY5Y) cells. The cell viability, calcium release, oxidative stress, HSP-70 expression, mitochondrial, and DNA damage, as well as cytoskeleton alteration, were evaluated. Results: Our results clearly demonstrate that the combined strategy markedly exerts anticancer effects against the tested cancer cell, while neither of the single treatments (only heat or only NPs) induced significant changes. Conclusions: Au NP@polyphenols may be powerful agents in cancer treatment.

Optical and Electrical Methods to Measure the Dynamic Behavior of a MEMS Gyroscope Sensor

2005 ◽  
Author(s):  
Alfredo Cigada ◽  
Elisabetta Leo ◽  
Marcello Vanali
Keyword(s):  
Laser Doppler Vibrometer ◽  
Mechanical Parameters ◽  
Mems Sensors ◽  
Electrical Method ◽  
Mems Gyroscope ◽  
Full Characterization ◽  
Design Specifications ◽  
Electrical Methods ◽  
Gyroscope Sensor

A full characterization of the mechanical parameters for vibrating MEMS sensors is required before integrating the mechanical and the electronic part. This is to verify that the main design specifications are fulfilled before sensors are available on the market. The main goal is to accurately establish the well-working devices in the shortest time. In this paper the electrical method based on the measurement of the GND current is used to satisfy this purpose. To check the validity of the achieved results through this method a comparison is done with those obtained through the widely used optical method based on vibration measurements through by means of a Laser Doppler Vibrometer (LDV).

Bone Elastometric Measurements by Ultrasound Reflectometry: Observations on Physiology and Functional Organization of Bone

2000 ◽  
Author(s):  
Shreefal S. Mehta ◽  
Peter P. Antich ◽  
Billy Smith ◽  
Matthew A. Lewis ◽  
Edmond Richer
Keyword(s):  
Mechanical Properties ◽  
Functional Organization ◽  
Muscular Activity ◽  
Diagnostic Techniques ◽  
Rate Of Change ◽  
Activity Levels ◽  
Bone Material ◽  
Clinical Observations ◽  
First Time

Abstract Bone mechanical properties are strongly dependent on orientation and optimally adapted to the directional stresses induced by load bearing and muscular activity. Spatial and directional homogeneity and a slow rate of change of material mechanical properties are commonly assumed in the literature. The assumptions are based on limitations of widespread diagnostic techniques but are contradicted by results from several established techniques, including ultrasound reflectometry. A device based on the ultrasound reflectometry technique measures the mechanical elasticity of bone noninvasively at multiple sites and orientations, making it possible to carry out longitudinal studies at any chosen location in vivo. In vivo elastometric measurements over the length of a tibia were obtained with this device, demonstrating quantitatively for the first time the spatial and directional heterogeneity of bone material properties in vivo. Clinical observations made on two subjects also suggest that bone does exhibit rapid changes in response to altered activity levels.

scholarly journals The autoantibody-mediated encephalitides: from clinical observations to molecular pathogenesis

2019 ◽  
Author(s):  
Sudarshini Ramanathan ◽  
Adam Al-Diwani ◽  
Patrick Waters ◽  
Sarosh R. Irani
Keyword(s):  
Cerebrospinal Fluid ◽  
Close Association ◽  
Autoimmune Encephalitis ◽  
Clinical Syndrome ◽  
Clinical Observations ◽  
Improved Outcomes ◽  
Clinical Syndromes ◽  
Specific Autoantibody ◽  
Autoantibody Detection

Abstract The autoimmune encephalitis (AE) syndromes have been characterised by the detection of autoantibodies in serum and/or cerebrospinal fluid which target the extracellular domains of specific neuroglial antigens. The clinical syndromes have phenotypes which are often highly characteristic of their associated antigen-specific autoantibody. For example, the constellation of psychiatric features and the multi-faceted movement disorder observed in patients with NMDAR antibodies are highly distinctive, as are the faciobrachial dystonic seizures observed in close association with LGI1 antibodies. These typically tight correlations may be conferred by the presence of autoantibodies which can directly access and modulate their antigens in vivo. AE remains an under-recognised clinical syndrome but one where early and accurate detection is critical as prompt initiation of immunotherapy is closely associated with improved outcomes. In this review of a rapidly emerging field, we outline molecular observations with translational value. We focus on contemporary methodologies of autoantibody detection, the evolution and distinctive nature of the clinical phenotypes, generalisable therapeutic paradigms, and finally discuss the likely mechanisms of autoimmunity in these patients which may inform future precision therapies.

Effect of hypobaric air, oxygen, heliox (50:50), or heliox (80:20) breathing on air bubbles in adipose tissue

2007 ◽  
Vol 103 (3) ◽  
pp. 757-762 ◽  
Author(s):  
O. Hyldegaard ◽  
J. Madsen
Keyword(s):  
Adipose Tissue ◽  
Sea Level ◽  
Bubble Growth ◽  
Decompression Sickness ◽  
Air Bubbles ◽  
Initial Growth ◽  
Oxygen Breathing ◽  
Clinical Observations ◽  
Measuring Techniques

The fate of bubbles formed in tissues during decompression to altitude after diving or due to accidental loss of cabin pressure during flight has only been indirectly inferred from theoretical modeling and clinical observations with noninvasive bubble-measuring techniques of intravascular bubbles. In this report we visually followed the in vivo resolution of micro-air bubbles injected into adipose tissue of anesthetized rats decompressed from 101.3 kPa to and held at 71 kPa corresponding to ∼2.750 m above sea level, while the rats breathed air, oxygen, heliox (50:50), or heliox (80:20). During air breathing, bubbles initially grew for 30–80 min, after which they remained stable or began to shrink slowly. Oxygen breathing caused an initial growth of all bubbles for 15–85 min, after which they shrank until they disappeared from view. Bubble growth was significantly greater during breathing of oxygen compared with air and heliox breathing mixtures. During heliox (50:50) breathing, bubbles initially grew for 5–30 min, from which point they shrank until they disappeared from view. After a shift to heliox (80:20) breathing, some bubbles grew slightly for 20–30 min, then shrank until they disappeared from view. Bubble disappearance was significantly faster during breathing of oxygen and heliox mixtures compared with air. In conclusion, the present results show that oxygen breathing at 71 kPa promotes bubble growth in lipid tissue, and it is possible that breathing of heliox may be beneficial in treating decompression sickness during flight.

scholarly journals Biocompatible Evaluation Of Biomaterials Used In The New Polish Extracorporeal Pulsatile Heart Assist Device ReligaHeart EXT

2015 ◽  
Vol 60 (3) ◽  
pp. 2271-2278 ◽  
Author(s):  
M. Gonsior ◽  
R. Kustosz ◽  
M. Kościelniak-Ziemniak ◽  
T. Wierzchoń
Keyword(s):  
Surface Engineering ◽  
Plasma Potential ◽  
Assist Device ◽  
Ventricular Assist ◽  
Polyether Ether Ketone ◽  
Valve Disc ◽  
Modified Surface ◽  
New Generation

Abstract The innovative extracorporeal heart support device ReligaHeart (RH EXT) has been developed, based on POLVAD ventricular assist device clinical experience, collected in more than 300 patient applications. The innovative surface engineering technologies are applied in ReligaHeart EXT device. The pump is manufactured of new generation, modified surface structure, biocompatible polyurethanes, and equipped with original tilting disc valves, Moll type. The valve ring is made of titanium alloy, TiN+Ti2N+αTi(N) diffusive layer modified, produced with glow discharge at plasma potential, in order to obtain the lowest thrombogenicity. The valve disc is made of polyether ether ketone. The complex in vitro and in vivo biological evaluations were performed, confirming both biomaterials biocompatible properties and device biocompatibility, proved in 30 days animal heart support.

In Vivo Caries Models-Mechanisms for Caries Initiation and Arrestment

1994 ◽  
Vol 8 (2) ◽  
pp. 144-157 ◽  
Author(s):  
A. Thylstrup ◽  
C. Bruun ◽  
L. Holmen
Keyword(s):  
Structural Changes ◽  
In Vivo Studies ◽  
Mechanical Forces ◽  
Clinical Observations ◽  
Mechanical Removal ◽  
Mineral Deposition ◽  
Partial Lesion ◽  
Lesion Regression ◽  
Clinical Experiments

The effects of intra-oral mechanical forces on caries initiation, progression, and arrestment are evaluated by examination of different in vivo caries models. The models are grouped in four categories: (1) a population study, (2) short-term clinical trials, (3) clinical experiments, and (4) controlled clinical observations. Taken together, these in vivo studies convincingly demonstrate that partial or total elimination of the intra-oral mechanical forces operating during mastication or toothbrushing leads to evolution of cariogenic plaque, resulting in localized carious enamel dissolution. In addition, they show that re-exposure to the partly or totally eliminated mechanical forces not only arrests further lesion progression, but also results in partial lesion regression. The data from in vivo caries studies also show that the clinical and structural changes associated with lesion arrestment or partial regression are not related to any salivary repair mechanism, but are solely the result of mechanical removal of the cariogenic biomass which is physically interrelated with the eroded surface of the active, dull-whitish enamel lesion. No indications of superficial mineral deposition or "blocking" of the external intercrystalline spaces are seen in the surface layer of lesions arrested in vivo. For this reason, the conventional usage of the terminology 'remineralization' is considered absolutely misleading when used to describe the mechanisms responsible for the arrest of lesion progression in vivo.

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