296 research outputs found

    Graphene coating obtained in a cold-wall CVD process on the Co-Cr Alloy (L-605) for medical applications

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    Graphene coating on the cobalt-chromium alloy was optimized and successfully carried out by a cold-wall chemical vapor deposition (CW-CVD) method. A uniform layer of graphene for a large area of the Co-Cr alloy (discs of 10 mm diameter) was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW-CVD process on the microstructure and the mor-phology of the Co-Cr surface was investigated by scanning X-ray photoelectron microscope (SPEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Nanoindentation and scratch tests were performed to determine mechanical properties of Co-Cr disks. The results of microbiological tests indicate that the studied Co-Cr alloys covered with a graphene layer did not show a pro-coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular diseases

    Synthesis of bifunctional thiophenes via Fiesselmann condensation of ynone trifluoroborate salts

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    Ynone trifluoroborate salts undergo a base-promoted condensation reaction with alkylthiols to generate thiophene boronates with complete regiocontrol. The products are isolated in high yield and can be further derivatized through conventional C-B bond functionalization reactions

    Design and synthesis of novel pyrazole based heterotricycles and their derivatization via automated library synthesis

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    Small molecule heterocycles bearing orthogonal functionality have the potential to deliver diverse structural motifs that aid the drug discovery effort. This work highlights how a readily assembled N ‐hydroxyethyl pyrazole trifluoroborate offers rapid access to architecturally distinct 5‐6‐6 and 5‐7‐6 fused tricyclic compounds. This chemistry is not only amenable to single compound synthesis, but also to high throughput experimentation. It enables easy access to diverse compound arrays with varying physchem and ADME profiles by fully automated library synthesis. The combination of the high throughput experimentation with rapid testing of the compounds in an integrated physchem and ADME profiling workflow allows accelerated design of novel lead compounds in drug discovery projects

    Synthesis and Modular Reactivity of Pyrazole 5-Trifluoroborates: Intermediates for the Preparation of Fully-Functionalized Pyrazoles.

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    The regioselective condensation of hydrazines and ynone trifluoroborates provides access to a range of pyrazole 5-trifluoroborates. The stability of the borate unit allows chemoselective halogenation of the heteroaromatic ring, thereby delivering pyrazole scaffolds that allow orthogonal functionalization at C5 and C4. The modular reactivity of these intermediates is exemplified by cross-coupling reactions, enabling regiocontrolled synthesis of fully-functionalized pyrazole derivatives

    Predictors of Performance during a 161 km Mountain Footrace

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    Training volume and cardiovascular dynamics influence endurance performance. However, there is limited information on the interplay between training volume, cardiovascular dynamics, and performance in ultra-marathon athletes. PURPOSE: We aimed to determine predictors of performance in finishers of the 2023 Western States Endurance Run (WSER). METHODS: Sixty participants who finished the race (49 males/11 females; mean age: 44.7 ± 9.6 y, range: 26–66 y; BMI: 22.7 ± 2.2 kg/m2) completed pre-race surveys including average training volume (AV) and peak training volume (PV), as well as resting cardiovascular measures including resting heart rate (RHR) and augmentation index (AIx), a measure of wave reflection characteristics. Based on WSER completion time, we calculated average running velocity (RV). We assessed associations among 22 variables using bivariate correlation analysis (Pearson’s Correlation for normally distributed data and Spearman’s Rank Correlation if normality was not met). Within our listed variables, normality was met in age and AV. Additionally, we completed multiple regression analyses for predictors. We present descriptive data as mean ± SD. RESULTS: Participants had an average RV of 6.33 ± 0.97 km/h (3.93 ± 0.6 mph), and reported an AV of 91.9 ± 24.5 km/wk (57.1 ± 15.2 miles/wk) and a PV of 141.0 ± 47.2 km/wk (87.6 ± 29.3 miles/wk). We observed significant associations between RV and age (r(58) = -0.57, p r(58) = 0.41, p r(58) = 0.34, p R2 = 0.37; F(3,56) = 12.4, pb1 = 0.013; t(56) = 2.57, p = 0.013), resulting in a 0.33 km/h increase in RV for every 25-km increase in AV. Last, significant relations existed between RV and AIx (r(58) = -0.30, p = 0.022); and RHR (r(58) = -0.26, p = 0.046). CONCLUSION: We found that (1) average weekly training volume is a significant predictor of performance in elite ultra-marathon athletes and (2) race performance was inversely associated with resting arterial wave reflection characteristics and heart rate

    Graphene Coating Obtained in a Cold Wall CVD Process on the Co Cr Alloy L 605 for Medical Applications

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    Graphene coating on the cobalt chromium alloy was optimized and successfully carried out by a cold wall chemical vapor deposition CW CVD method. A uniform layer of graphene for a large area of the Co Cr alloy discs of 10 mm diameter was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW CVD process on the microstructure and the morphology of the Co Cr surface was investigated by scanning X ray photoelectron microscope SPEM , atomic force microscopy AFM , scanning electron microscopy SEM , and energy dispersive X ray spectroscopy EDS . Nanoindentation and scratch tests were performed to determine mechanical properties of Co Cr disks. The results of microbiological tests indicate that the studied Co Cr alloys covered with a graphene layer did not show a pro coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular disease
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