776 research outputs found
A polymer coated cicaprost-eluting stent increases neointima formation and impairs vessel function in the rabbit iliac artery
Drug-eluting stents have been successful in reducing in-stent restenosis but are not suitable for all lesion types and have been implicated in causing late stent thrombosis due to incomplete regeneration of the endothelial cell layer. In this study we implanted stents coated with cicaprost, a prostacyclin analogue with a long plasma half-life and antiproliferative effects on vascular smooth muscle cells, into the iliac arteries of rabbits. At 28-day follow-up we compared neointima formation within the stented vessels and vascular function in adjacent vessels, to assess if cicaprost could reduce restenosis without impairing vessel function. Arteries implanted with cicaprost eluting stents had significantly more neointima compared to bare metal stents. In adjacent segments of artery, endothelium-dependent relaxation was impaired by the cicaprost-eluting stent but vasodilation to an endothelium-independent vasodilator was maintained. We conclude that the presence of the polymer and sub-optimal release of cicaprost from the stent may be responsible for the increased neointma and impaired functional recovery of the endothelium observed. Further experiments should be aimed at optimising release of cicaprost and exploring different stent polymer coatings
The Private Provision of Public Goods: An Analysis of Homes on Golf Courses
This paper examines the joint production of golf and real estate development. The empirical results of this analysis show that, over time, golf courses are being constructed less for recreational golf and more for contractual assurance of green open space for homes. We believe that this fundamentally provides some evidence that the demand for environmental quality is growing and that markets are increasingly able to find creative contracting mechanisms to satisfy demands for public goods
Access to Nitrogen Heterocycles via Borrowing Hydrogen Catalysis
Nitrogen heterocycles are ubiquitous motifs which occur as the core structure of several alkaloid natural products exhibiting inherent biological activity against an array of bacteria, fungi, viruses, and cancer cell lines. These azacycles serve as key synthetic building blocks for medicinal chemists to access more structurally complex and diverse compounds with tunable biological properties. A synthetic approach to these valuable motifs employing intramolecular borrowing hydrogen catalysis has been developed. The utility of the developed chemistry will be applied to synthetic efforts towards the recently isolated Cylicomorphins A-E
A polymer coated cicaprost-eluting stent increases neointima formation and impairs vessel function in the rabbit iliac artery
Drug-eluting stents have been successful in reducing in-stent restenosis but are not suitable for all lesion types and have been implicated in causing late stent thrombosis due to incomplete regeneration of the endothelial cell layer. In this study we implanted stents coated with cicaprost, a prostacyclin analogue with a long plasma half-life and antiproliferative effects on vascular smooth muscle cells, into the iliac arteries of rabbits. At 28 day follow-up we compared neointima formation within the stented vessels and vascular function in adjacent vessels, to assess if cicaprost could reduce restenosis without impairing vessel function. Arteries implanted with cicaprost eluting stents had significantly more neointima compared to bare metal stents. In adjacent segments of artery, endothelium-dependent relaxation was impaired by the cicaprost-eluting stent but vasodilation to an endothelium-independent vasodilator was maintained. We conclude that the presence of the polymer and sub-optimal release of cicaprost from the stent may be responsible for the increased neointma and impaired functional recovery of the endothelium observed. Further experiments should be aimed at optimising release of cicaprost and exploring different stent polymer coatings
Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System
Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed
The Sex Ratio and the Out-of-Wedlock Birth Rate in the United States during World War II
This paper provides a theoretical economic framework to study the effects of changes in the sex ratio on the out-of-wedlock birth rate in the United States. We model the demanders and suppliers of sexual relations as potential mates and the relative āpriceā of human sexual relations as the promises implicit within a traditional marriage (marriage, fidelity, wealth transfers, child support, etc.). We examine an instrument for the implicit āpriceā of sexual relations, namely the out-of-wedlock birth rate. We show that the reduction in the number of available sex partners for women during World War II decreased the āpriceāāin terms of marriageāthat remaining men had to pay for sex. One result of this lower āpriceā is an increase in the number of children born out-of-wedlock during the war. According to our regression results, a reduction in the sex ratio of 10 males per 100 females in the U.S. population during World War II increased the out-of wedlock birth rate by six to ten percent
Systematic review and meta-analysis of clinical outcomes after management of posterior cruciate ligament tibial avulsion fractures
BACKGROUND: There is no consensus regarding the management of posterior cruciate ligament (PCL) avulsion fractures and the expected outcomes after treatment.
PURPOSE: To systematically review clinical outcomes and complications after management of tibial-sided avulsion fractures of the PCL.
STUDY DESIGN: Systematic review; Level of evidence, 4.
METHODS: A literature search of Scopus, PubMed, Medline, and the Cochrane Central Register for Controlled Trials was performed in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included were studies with evidence levels 1 to 4 that reported clinical outcomes after treatment of PCL tibial-sided avulsion fractures in humans. The quality of the included studies was performed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. A meta-analysis was performed for patient-reported outcome measures using random-effects modeling with 95% CIs.
RESULTS: A total of 58 studies published between 1999 and 2022 were identified. The mean MINORS score was 9.90 Ā± 4.12, indicating overall low-quality evidence with high risk of bias. The studies comprised 1440 patients (mean age, 32.59 Ā± 5.69 years; 75.2% males) with a mean follow-up of 26.9 Ā± 19.6 months (range, 5.3-126 months). Most patients were treated with open surgery (63.6%), followed by arthroscopic surgery (29.7%) and nonoperative treatment (6.7%). All patients reported significant posttreatment improvement in both subjective and objective outcomes (
CONCLUSION: Although nonoperative and surgical management of PCL tibial avulsion fractures resulted in high rates of fracture union and improvement in functional outcome scores and a low incidence of complications, nonoperative treatment yielded a high side-to-side posterior displacement (\u3e4 mm) with a lower rate of fracture union compared to surgical treatment
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