163 research outputs found
A biosynthetically inspired route to substituted furans using the Appel reaction: total synthesis of the furan fatty acid F<sub>5</sub>
Appel reaction conditions have been harnessed to affect a mild biosynthetically inspired dehydration of endoperoxides to deliver multi-substituted electron rich furans. Unlike traditional dehydrative procedures, this method is metal and acid free, and can be achieved under redox neutral conditions. It is general for a range of aryl and alkyl substituted endoperoxides, and is functional group tolerant. Furthermore, this procedure has been used to deliver an effective total synthesis of the furan fatty acid (FFA) F5
Considerations for How to Rate CPV
The concentrator photovoltaic (CPV) industry is introducing multiple products into the marketplace, but, as yet, the community has not embraced a unified method for assessing a nameplate rating. The choices of whether to use 850, 900, or 1000 W/m2 for the direct-normal irradiance and whether to link the rating to ambient or cell temperature will affect how CPV modules are rated and compared with other technologies. This paper explores the qualitative and quantitative ramifications of these choices using data from two multi-junction CPV modules and two flat-plate modules
Persistent and Consistent Underpromotion of Women in Academic Medicine: It's Time to Make Some Waves
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Association of a Workplace Sales Ban on Sugar-Sweetened Beverages With Employee Consumption of Sugar-Sweetened Beverages and Health.
ImportanceReductions in sugar-sweetened beverage (SSB) intake can improve health, but are difficult for individuals to achieve on their own.ObjectivesTo evaluate whether a workplace SSB sales ban was associated with SSB intake and cardiometabolic health among employees and whether a brief motivational intervention provides added benefits to the sales ban.Design, setting, and participantsThis before-after study and additional randomized trial conducted from July 28, 2015, to October 16, 2016, at a Northern California university and hospital assessed SSB intake, anthropometrics, and cardiometabolic biomarkers among 214 full-time English-speaking employees who were frequent SSB consumers (≥360 mL [≥12 fl oz] per day) before and 10 months after implementation of an SSB sales ban in a large workplace, with half the employees randomized to receive a brief motivational intervention targeting SSB reduction.InterventionsThe employer stopped selling SSBs in all workplace venues, and half the sample was randomized to receive a brief motivational intervention and the other half was a control group that did not receive the intervention. This intervention was modeled on standard brief motivational interventions for alcohol used in the workplace that promote health knowledge and goal setting.Main outcomes and measuresOutcomes included changes in SSB intake, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and measures of abdominal adiposity. The primary associations tested were the correlation between changes in SSB intake and changes in HOMA-IR.ResultsAmong the 214 study participants, 124 (57.9%) were women, with a mean (SD) age of 41.2 (11.0) years and a baseline mean (SD) body mass index of 29.4 (6.5). They reported a mean daily intake of 1050 mL (35 fl oz) of SSBs at baseline and 540 mL (18 fl oz) at follow-up-a 510-mL (17-fl oz) (48.6%) decrease (P < .001). Reductions in SSB intake correlated with improvements in HOMA-IR (r = 0.16; P = .03). Those not randomized to receive the brief intervention reduced their SSB intake by a mean (SD) of 246.0 (84.0) mL (8.2 [2.8] fl oz), while those also receiving the brief intervention reduced SSB intake by 762.0 (84.0) mL (25.4 [2.8] fl oz). From baseline to follow-up, there were significant reductions in mean (SE) waist circumference (2.1 [2.8] cm; P < .001).Conclusions and relevanceThis study's findings suggest that the workplace sales ban was associated with a reduction in SSB intake and a significant reduction in waist circumference among employees within 10 months. The randomized clinical trial portion of this study found that targeting those at high risk with a brief motivational intervention led to additional improvements. Workplace sales bans may offer a promising new private-sector strategy for reducing the health harms of SSB intake.Trial registrationClinicalTrials.gov identifier: NCT02585336
In situ monitoring and mechanism of the mechanochemical formation of a microporous MOF-74 framework
Mechanochemistry provides a rapid, efficient route to metal-organic framework Zn-MOF-74 directly from a metal oxide and without bulk solvent. In situ synchrotron X-ray diffraction monitoring of the reaction course reveals two new phases and an unusual step-wise process in which a close-packed intermediate reacts to form the open framework. The reaction can be performed on a gram scale to yield a highly porous material after activation
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