scholarly journals Noble Metals for Modern Implant Materials: MOCVD of Film Structures and Cytotoxical, Antibacterial, and Histological Studies

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 851
Author(s):  
Svetlana I. Dorovskikh ◽  
Evgeniia S. Vikulova ◽  
Elena V. Chepeleva ◽  
Maria B. Vasilieva ◽  
Dmitriy A. Nasimov ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Noble Metals ◽  
Mononuclear Cells ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Ti Alloy ◽  
Peripheral Blood Mononuclear ◽  
Histological Studies

This work is aimed at developing the modification of the surface of medical implants with film materials based on noble metals in order to improve their biological characteristics. Gas-phase transportation methods were proposed to obtain such materials. To determine the effect of the material of the bottom layer of heterometallic structures, Ir, Pt, and PtIr coatings with a thickness of 1.4–1.5 μm were deposited by metal–organic chemical vapor deposition (MOCVD) on Ti6Al4V alloy discs. Two types of antibacterial components, namely, gold nanoparticles (AuNPs) and discontinuous Ag coatings, were deposited on the surface of these coatings. AuNPs (11–14 nm) were deposited by a pulsed MOCVD method, while Ag films (35–40 nm in thickness) were obtained by physical vapor deposition (PVD). The cytotoxic (24 h and 48 h, toward peripheral blood mononuclear cells (PBMCs)) and antibacterial (24 h) properties of monophase (Ag, Ir, Pt, and PtIr) and heterophase (Ag/Pt, Ag/Ir, Ag/PtIr, Au/Pt, Au/Ir, and Au/PtIr) film materials deposited on Ti-alloy samples were studied in vitro and compared with those of uncoated Ti-alloy samples. Studies of the cytokine production by PBMCs in response to incubation of the samples for 24 and 48 h and histological studies at 1 and 3 months after subcutaneous implantation in rats were also performed. Despite the comparable thickness of the fibrous capsule after 3 months, a faster completion of the active phase of encapsulation was observed for the coated implants compared to the Ti alloy analogs. For the Ag-containing samples, growth inhibition of S. epidermidis, S. aureus, Str. pyogenes, P. aeruginosa, and Ent. faecium was observed.

scholarly journals Monometallic Pd and Pt and Bimetallic Pd-Pt/Al2O3-TiO2for the HDS of DBT: Effect of the Pd and Pt Incorporation Method

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Reynaldo Martínez Guerrero ◽  
Agileo Hernández-Gordillo ◽  
Víctor Santes ◽  
Jorge Roberto Vargas García ◽  
José Escobar ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Noble Metals ◽  
Preparation Method ◽  
Synergetic Effect ◽  
Chemical Vapor ◽  
Pt Catalyst ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Incorporation Method

The effect of the preparation method of monometallic Pd and Pt and bimetallic Pd-Pt/Al2O3-TiO2catalysts on the hydrodesulfurization (HDS) of dibenzothiophene (DBT) was investigated in this study. The synthesis was accomplished using three methods: (A) impregnation, (B) metal organic chemical vapor deposition (MOCVD), and (C) impregnation-MOCVD. The bimetallic Pd-Pt catalyst prepared by the impregnation-MOCVD method was most active for the HDS of DBT compared to those prepared by the single impregnation or MOCVD method due to the synergetic effect between both noble metals. The greater selectivity toward biphenyl indicated that this bimetallic Pd-Pt catalyst preferentially removes sulfur via the direct desulfurization mechanism. However, the bimetallic Pd-Pt catalyst prepared using the single MOCVD method did not produce any cyclohexylbenzene, which is most likely associated with the hydrogenation/dehydrogenation sites.

Thermodynamic Constraints for the In Situ MOCVD Growth of Superconducting Tl-Ba-Ca-Cu-O Thin Films

1993 ◽  
Vol 335 ◽  
Author(s):  
William L. Holstein
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Mocvd Growth ◽  
Metal Organic ◽  
Deposition Processes ◽  
Organic Chemical Vapor Deposition

AbstractIn spite of several attempts, superconducting Tl-Ba-Ca-Cu-O thin films have not been successfully prepared in situ by metal organic chemical vapor deposition (MOCVD). Preparation of a phase by MOCVD requires that it be thermodynamically stable with respect to its decomposition into volatile species and other condensed phases. For MOCVD growth of Tl-Ba- Ca-Cu-O compounds in the presence of oxygen from reagents containing only C-H or C-H-O ligands, Tl2O(g) and TIOH(g) exhibit appreciable volatility. If reagents with ligands containing fluorine are used, the formation of volatile TIF(g) must also be considered. Thermodynamic data for these materials are compiled, and thermodynamic relationships between these gases, H2O(g) and HF(g) are established. The thermodynamic stability of TIOH(g) and TIF(g) makes the in situ growth of Tl-Ba-Ca-Cu-O compounds by MOCVD more difficult than their in situ growth by physical vapor deposition processes, for which Tl2O(g) is the only volatile TI-containing species present.

A New Model to Test Platelet Adhesion under Dynamic Conditions

1993 ◽  
Vol 16 (7) ◽  
pp. 545-550 ◽  
Author(s):  
I. Dion ◽  
C. Baquey ◽  
P. Havlik ◽  
J.R. Monties
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Platelet Adhesion ◽  
Construction Materials ◽  
Chemical Vapor ◽  
Ceramic Coatings ◽  
New Model ◽  
Systemic Error ◽  
The Difference

In order to evaluate under dynamic circumstances the in vitro platelet adhesion induced by rigid materials such as ceramic coatings deposited on selected substrates, a new model simulating a tube has been designed. In vitro platelet adhesion was assessed with this new model: the material was titanium nitride (TiN) deposited on Ti6A14V (TA6V) titanium alloy by a physical vapor deposition (PVD) process. The results were compared to those obtained with complete titanium carbide (TiC) graphite tubes coated with TiN by a chemical vapor deposition (CVD) process. The difference observed (less than 25%) in favour of the new system, could be due to the better surface state of the construction materials of this system. In fact it is a systemic error. However TiN confirms its good performance as a blood-contacting biomaterial.

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

Preliminary Report of In vitro and In vivo Effectiveness of Dornase Alfa on SARS-CoV-2 Infection (Preprint)

2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Mononuclear Cells ◽  
Multiple Organ ◽  
Peripheral Blood Mononuclear ◽  
Dornase Alfa ◽  
Tract Infections ◽  
Adult Peripheral Blood

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.

scholarly journals Laser‐Assisted Metal–Organic Chemical Vapor Deposition of Gallium Nitride

2021 ◽  
Vol 15 (6) ◽  
pp. 2170024
Author(s):  
Yuxuan Zhang ◽  
Zhaoying Chen ◽  
Kaitian Zhang ◽  
Zixuan Feng ◽  
Hongping Zhao
Keyword(s):  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition
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