Spacecraft sample collection and subsurface excavation of asteroid (101955) Bennu.

Carbonaceous asteroids, such as (101955) Bennu, preserve material from the early Solar System, including volatile compounds and organic molecules. We report spacecraft imaging and spectral data collected during and after retrieval of a sample from Bennu's surface. The sampling event mobilized rocks and dust into a debris plume, excavating a 9-meter-long elliptical crater. This exposed material is darker, spectrally redder, and more abundant in fine particulates than the original surface. The bulk density of the displaced subsurface material was 500 to 700 kilograms per cubic meter, which is about half that of the whole asteroid. Particulates that landed on instrument optics spectrally resemble aqueously altered carbonaceous meteorites. The spacecraft stored 250 ± 101 grams of material, which will be delivered to Earth in 2023.

Improving pneumococcal vaccine uptake in veterans with chronic lymphocytic leukemia through a virtual clinic.

Through a "virtual clinic," we used the electronic medical record to identify and intervene upon patients with chronic lymphocytic leukemia (cll) who were not current for pneumococcal vaccines. Within 180 days, 100/160 patients (62%) received the recommended pneumococcal vaccine. A virtual clinic may improve vaccination rates among high-risk patient populations.

Activation of lipoprotein lipase by native and acylated peptides of apolipoprotein C-II.

Apolipoprotein C-II, a protein found associated with all major classes of plasma lipoproteins, is a potent activator of the enzyme lipoprotein lipase. We have prepared the maleyl, citraconyl and succinyl derivatives of apolipoprotein C-II, and compared the capacities of the intact and tryptically cleaved proteins to activate lipoprotein lipase. The NH2-terminal 50 residue peptide proved virtually inactive, even after removal of the masking groups from the citraconyl derivative. The COOH-terminal 29 residue peptides of maleyl and citraconyl apolipoprotein C-II were more active than the corresponding succinylated peptide. After deacylation of the citraconyl derivative, the COOH-terminal peptide had maximal activity as great as apolipoprotein C-II, although the profile of activation remained dissimilar at low activator concentrations.

Lipoprotein lipase cofactor activity of a carboxyl-terminal peptide of apolipoprotein C-II.

Apolipoprotein C-II (apoC-II) is a small protein found associated with the plasma lipoproteins. It serves a unique function in the activation of the enzyme lipoprotein lipase (triacylglycerol acyl-hydrolase, EC 3.1.1.3). ApoC-II contains a single arginine residue, permitting tryptic cleavage into two peptides after succinylation of the native protein. The succinylated amino-terminal peptide, approximately 50 residues, did not activate lipoprotein lipase. The succinylated carboxyl-terminal peptide, about 29 residues, had significant cofactor activity. Relative to native apoC-II, the maximal activation observed with the succinylated carboxyl-terminal peptide was 50% lower and the concentration required for half-maximal activity was approximately 10 times higher. Mixtures of the carboxyl- and amino-terminal peptides had no more activity than the carboxyl-terminal peptide alone. Localization of functional properties to the carboxyl region is a feature also common to apolipoproteins C-III, A-II, and A-I.