Preparation and property evaluation of biodegradable elastomeric PTMC/PLCL networks used as ureteral stents

2021 ◽  
pp. 127550
Author(s):  
Xiliang Liu ◽  
Song Liu ◽  
Kaiqi Li ◽  
Youkun Fan ◽  
Shaomin Feng ◽  
...  
Keyword(s):  
Ureteral Stents ◽  
Property Evaluation

NiAl precipitation in Fe-12w/o Cr-5w/o Ni-4w/o Al

1983 ◽  
Vol 41 ◽  
pp. 202-203
Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Alloy Composition ◽  
Chromium Content ◽  
Scale Up ◽  
Optical Metallography ◽  
Property Evaluation ◽  
310 Stainless Steel ◽  
Microstructural Studies

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.

scholarly journals Characteristics of Biodegradable Gelatin Methacrylate Hydrogel Designed to Improve Osteoinduction and Effect of Additional Binding of Tannic Acid on Hydrogel

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2535
Author(s):  
Ji-Bong Choi ◽  
Yu-Kyoung Kim ◽  
Seon-Mi Byeon ◽  
Jung-Eun Park ◽  
Tae-Sung Bae ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Water Absorption ◽  
Tannic Acid ◽  
Absorption Capacity ◽  
Animal Testing ◽  
High Concentration ◽  
Cell Compatibility ◽  
Property Evaluation ◽  
Bone Minerals ◽  
Cell Adhesion And Proliferation

In this study, a hydrogel using single and double crosslinking was prepared using GelMA, a natural polymer, and the effect was evaluated when the double crosslinked hydrogel and tannic acid were treated. The resulting hydrogel was subjected to physicochemical property evaluation, biocompatibility evaluation, and animal testing. The free radicals generated through APS/TEMED have a scaffold form with a porous structure in the hydrogel, and have a more stable structure through photo crosslinking. The double crosslinked hydrogel had improved mechanical strength and better results in cell compatibility tests than the single crosslinked group. Moreover, in the hydrogel transplanted into the femur of a rat, the double crosslinked group showed an osteoinductive response due to the attachment of bone minerals after 4 and 8 weeks, but the single crosslinked group did not show an osteoinductive response due to rapid degradation. Treatment with a high concentration of tannic acid showed significantly improved mechanical strength through H-bonding. However, cell adhesion and proliferation were limited compared to the untreated group due to the limitation of water absorption capacity, and no osteoinduction reaction was observed. As a result, it was confirmed that the treatment of high-concentration tannic acid significantly improved mechanical strength, but it was not a suitable method for improving bone induction due to the limitation of water absorption.

scholarly journals Internal Coating of Ureteral Stents with Chemical Vapor Deposition of Parylene

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 739
Author(s):  
Sara Felicitas Bröskamp ◽  
Gerhard Franz ◽  
Dieter Jocham
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Silver Ions ◽  
Daily Basis ◽  
Second Step ◽  
Silver Layer ◽  
Main Concern ◽  
Ureteral Stents ◽  
Balloon Catheters

Ureteral balloon catheters and ureteral stents are implanted in large quantities on a daily basis. They are the suspected cause for about a quarter of all the nosocomial infections, which lead to approx. 20,000 deaths in Germany alone. To fight these infections, catheters should be made antibacterial. A technique for an antibacterial coating of catheters exhibiting an aspect ratio of up to 200 consists of a thin silver layer, which is deposited out of an aqueous solution, which is followed by a second step: chemical vapor deposition (CVD) of an organic polymeric film, which moderates the release rate of silver ions. The main concern of the second step is the longitudinal evenness of the film. For tubes with one opening as balloon catheters, this issue can be solved by applying a descendent temperature gradient from the opening to the end of the catheter. An alternative procedure can be applied to commercially available ureteral stents, which exhibit small drainage openings in their middle. The same CVD as before leads to a longitudinal homogeneity of about ±10%—at very low costs. This deposition can be modeled using viscous flow.

Property evaluation of spin coated Al doped ZnO thin films and au/azo/fto Schottky diodes

2021 ◽  
pp. 106903
Author(s):  
Chaitra U ◽  
A.V. Muhammed Ali ◽  
Mahesha M. G ◽  
Akshaykumar Kompa ◽  
Dhananjaya Kekuda ◽  
...  
Keyword(s):  
Thin Films ◽  
Schottky Diodes ◽  
Zno Thin Films ◽  
Property Evaluation ◽  
Doped Zno

Preparing and characterizing biodegradable materials for ureteral stents

2021 ◽  
Author(s):  
Haipo Cui ◽  
Kui Zhang ◽  
Chenguang Gao ◽  
Yahong Kang ◽  
Hongyan Jiang ◽  
...  
Keyword(s):  
Biodegradable Materials ◽  
Ureteral Stents
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