Formation of functional monolayers on surfaces of carbon materials is inherently difficult because of the high bond strength of carbon and because common pathways such as SN2 mechanisms cannot take place at surfaces of solid materials. Here, we show that the radical initiators can selectively abstract H atoms from H-terminated carbon surfaces, initiating regioselective grafting of terminal alkenes to surfaces of diamond, glassy carbon, and polymeric carbon dots. Nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) demonstrate formation of self-terminating organic monolayers linked via the terminal C atom of 1-alkenes. Density functional theory (DFT) calculations suggest that this selectivity is at least partially thermodynamic in origin, as significantly less energy is needed to abstract H atoms from carbon surfaces as compared to typical aliphatic compounds. The regioselectivity favoring binding to the terminal C atom of the reactant alkenes arises from steric hindrance encountered in bond formation at the adjacent carbon atom. Our results demonstrate that carbon surface radical chemistry yields a versatile, selective, and scalable approach to monolayer formation on H-terminated carbon surfaces and provide mechanistic insights into the surface selectivity and regioselectivity of molecular grafting.

Establishing science-based driving per se blood Δ -tetrahydrocannabinol (THC) limits is challenging, in part because of prolonged THC detection in chronic, frequent users. Therefore, documenting observable signs of impairment is important for driving under the influence of drugs. We evaluated frequent and occasional cannabis smokers' performance on the modified Romberg balance, one leg stand (OLS), and walk and turn (WAT) tasks, and pupil size effects following controlled placebo (0.001% THC), smoked, vaporized and oral (6.9% [~50.4 mg] THC) cannabis administration. Significant effects following inhaled doses were not observed due to delayed tasks administration 1.5 and 3.5 h post-dose, but significant impairment was observed after oral dosing (blood THC concentrations peaked 1.5-3.5 h post-dose). Occasional smokers' odds of exhibiting ≥2 clues on the OLS or WAT following oral dosing were 6.4 (95% CI 2.3-18.4) times higher than after placebo, with THC and 11-hydroxy-THC blood concentrations individually producing odds ratios of 1.3 (1.1-1.5) and 1.5 (1.3-1.8) for impairment in these tasks, respectively. Pupil sizes after oral dosing under the direct lighting condition were significantly larger than after placebo by mean (SE, 95% CI) 0.4 (0.1, 0.2-0.6) mm at 1.5 h and 0.5 (0.2, 0.2-0.8) mm at 3.5 h among all participants. Oral cannabis administration impaired occasional cannabis users' performance on the OLS and WAT tasks compared to placebo, supporting other reports showing these tasks are sensitive to cannabis-related impairment. Occasional smokers' impairment was related to blood THC and 11-hydroxy-THC concentrations. These are important public health policy findings as consumption of edible cannabis products increases. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Biomineralization processes govern the formation of hierarchical hard tissues such as bone and teeth in living organisms, and mimicking these processes could lead to the design of new materials with specialized properties. However, such advances require structural characterization of the proteins guiding biomineral formation to understand and mimic their impact. In their ''active'' form, biomineralization proteins are bound to a solid surface, severely limiting our ability to use many conventional structure characterization techniques. Here, solid-state NMR spectroscopy was applied to study the intermolecular interactions of amelogenin, the most abundant protein present during the early stages of enamel formation, in self-assembled oligomers bound to hydroxyapatite. Intermolecular dipolar couplings were identified that support amelogenin dimer formation stabilized by residues toward the C-termini. These dipolar interactions were corroborated by molecular dynamics simulations. A b-sheet structure was identified in multiple regions of the protein, which is otherwise intrinsically disordered in the absence of hydroxyapatite. To our knowledge, this is the first intermolecular protein-protein interaction reported for a biomineralization protein, representing an advancement in understanding enamel development and a new general strategy toward investigating biomineralization proteins.

Bonneville Power Administration carries out generation and conservation resource planning. The analysis of historical trends in and determinants of energy consumption is carried out by the office's End-Use Research Section. The End-Use Research Section operates a comprehensive data collection program to provide pertinent information to support demand-side conservation planning, load forecasting, and conservation program development and delivery. Part of this ongoing program, commonly known as the End-Use Load and Consumer Assessment Program (ELCAP), was recently renamed the Regional End-Use Metering Project (REMP) to reflect an emphasis on metering rather than analytical activities. REMP is designed to collect electricity usage data through direct monitoring of end-use loads in buildings in the residential and commercial sectors and is conducted for Bonneville by Pacific Northwest Laboratories (Battelle). The detailed summary information in this report is on energy used for water heaters in the residential sector and is based on data collected from September 1985 through December 1990 for 336 of the 499 REMP metered homes. Specific information is provided on annual loads averaged over the years and their variation across residences. Descriptions are given of use as associated with demographic and energy-related characteristics. Summaries are also provided for electricity use by each year, month, and daytype, as well as at peak hot water load and peak system times. This is the second residential report. The first report, Description of Electric Energy Use in Single-Family Residences in the Pacific Northwest (ELCAP) (1989), provides extensive background information on residential metering and serves as a sourcebook of summarized residential data for every end use metered. This second report focuses on a specific end use and adds detail to the first report. Subsequent reports are planned on other individual end uses or sets of end uses. Comments regarding the interpretation of the data presented, requests for additional useful data summaries, or requests for an electronic version of the data summaries should be directed to: