Evolving Role of Exosomes in Plastic and Reconstructive Surgery and Dermatology.

Exosomes, or extracellular vesicles, represent the latest cell-free addition to the regenerative medicine toolkit. In vitro preclinical studies have demonstrated the safety and efficacy of exosomes, which vary based on source and biomanufacturing, for a myriad of potential therapeutic applications relevant to skin and soft tissue reconstruction. Primary search was performed in September 2021 on the MEDLINE database via PubMed and Ovid, with focus on articles about therapeutic application of exosomes or extracellular vesicles.

Amine-free approach toward N-toluenesulfonyl amidine construction: a phosphite-mediated Beckmann-like coupling of oximes and p-toluenesulfonyl azide.

Atom hopping: A chlorophosphite-mediated Beckmann ligation of oximes and p-toluenesulfonyl azide gives access to N-sulfonyl phosphoramidines in good to excellent yields. The reaction proceeds under exceptionally mild conditions and constitutes a bioorthogonal approach toward amidines by avoiding the use of amines and transition-metal catalysts. dmp-ol=3,3-dimethylpropanediol.

Direct acyl substitution of carboxylic acids: a chemoselective O- to N-acyl migration in the traceless Staudinger ligation.

A chlorophosphite-modified, Staudinger-like acylation of azides involving a highly chemoselective, direct nucleophilic acyl substitution of carboxylic acids is described. The reaction provides the corresponding amides with analytical purity in 32-97% yield after a simple aqueous workup without the need for a pre-activation step. The use of chlorophosphites as dual carboxylic acid-azide activating agents enables the formation of acyl C-N bonds in the presence of a wide range of nucleophilic and electrophilic functional groups, including amines, alcohols, amides, aldehydes, and ketones.

Scavenging: how carnivores and carrion structure communities.

Recent advances in the ecology of food webs underscore the importance of detritus and indirect predator-prey effects. However, most research considers detritus as an invariable pool and predation as the only interaction between carnivores and prey. Carrion consumption, scavenging, is a type of detrital feeding that should have widespread consequences for the structure and stability of food webs.

Pollen foraging behaviour of solitary Hawaiian bees revealed through molecular pollen analysis.

Obtaining quantitative information concerning pollinator behaviour has become a primary objective of pollination studies, but methodological limitations hinder progress towards this goal. Here, we use molecular genetic methods in an ecological context to demonstrate that endemic Hawaiian Hylaeus bees (Hymenoptera: Colletidae) selectively collect pollen from native plant species in Haleakala and Hawaii Volcanoes National Parks. We identified pollen DNA from the crops (internal storage organs) of 21 Hylaeus specimens stored in ethanol for up to 3 years.

Predation or scavenging? Thoracic muscle pH and rates of water loss reveal cause of death in arthropods.

The difficulty of directly observing predatory events hinders a complete understanding of how predation structures food webs. Indirect approaches such as PCR-based and isotopic analyses clarify patterns of resource consumption but fail to distinguish predation from scavenging. Given that facultative scavenging is a ubiquitous and phylogenetically widespread foraging strategy, an improved ability to discriminate prey from carrion is needed to enhance an understanding of the demographic effects of consumption and the true nature of trophic interactions.

Life history plasticity magnifies the ecological effects of a social wasp invasion.

An unresolved question in ecology concerns why the ecological effects of invasions vary in magnitude. Many introduced species fail to interact strongly with the recipient biota, whereas others profoundly disrupt the ecosystems they invade through predation, competition, and other mechanisms. In the context of ecological impacts, research on biological invasions seldom considers phenotypic or microevolutionary changes that occur following introduction.

Three structural roles for water in bone observed by solid-state NMR.

Hydrogen-bearing species in the bone mineral environment were investigated using solid-state NMR spectroscopy of powdered bone, deproteinated bone, and B-type carbonated apatite. Using magic-angle spinning and cross-polarization techniques three types of structurally-bound water were observed in these materials. Two of these water types occupy vacancies within the apatitic mineral crystal in synthetic carbonated apatite and deproteinated bone and serve to stabilize these defect-containing crystals.

Highly ordered interstitial water observed in bone by nuclear magnetic resonance.

Unlabelled: NMR was used to study the nanostructure of bone tissue. Distance measurements show that the first water layer at the surface of the mineral in cortical bone is structured. This water may serve to couple the mineral to the organic matrix and may play a role in deformation.

Synthesis of a digermane-containing tricylic nonadecadienedione incorporating an equivalent of ring-opened THF.

The combination of 2 equiv of bis[bis(trimethylsilyl)amide]germylene (5) with 2 equiv of 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) in tetrahydrofuran (THF) results in the ring-opening of 1 equiv of THF to form 2,2,8,8-tetrakis(1,1,1,3,3,3-hexamethyl-disilazan-2-yl)-5,16-diphenyl-7,9,14-trioxa-1,3,5,16,18,19-hexaaza-2,8-digerma-tricyclo[13.2.1.

Comparison of "polynaphthalenes" prepared by two mechanistically distinct routes.

The Bergman cyclization has long been known to produce polymers as side products. More recently, this attribute has been harnessed for the production of conjugated materials. However, the structures of these polymers have not been established.

Determination of the conformation and stability of simple homopolypeptides using solid-state NMR.

15N CPMAS, 13C CPMAS and 1H CRAMPS spectra of several polypeptide samples were compared to determine the useful features of each technique. 13C CPMAS is the most well-established technique and is useful for quick determination of secondary structure. The 15N nucleus is more sensitive to exact hydrogen-bonding parameters, which complicates interpretation of the spectra.