A visible-light activatable photoacid has been studied, which upon irradiation, changes from a weak acid, with a pK(a) of 7.8, to a strong acid, which achieves nearly complete proton dissociation. This process is reversible and the half-life of the proton-dissociation state is ~70s. The long lifetime of the proton-dissociation state is due to a sequential intramolecular photochromic reaction. Using this photoacid, a pH change of 2.2 units has been achieved. In addition, we demonstrated that the photoinduced proton concentration can catalyze an esterification reaction, and greatly alter the volume of a pH-sensitive polymer. This work shows that acid-catalyzed and pH-sensitive processes can be photochemically controlled by using this type of photoacid.

Saliva specimen has high sensitivity and specificity in the detection of respiratory viruses by an automated multiplex Clinical Laboratory Improvement Amendments (CLIA)-waived point-of-care molecular assay when compared with that of NPA. The use of saliva also reduces the time and cost associated with specimen collection.

Novel organic photoCORMs based on micelle-encapsulated unsaturated cyclic α-diketones were designed and synthesized. These photoCORMs can be activated by visible light, have potentially low toxicity, allow the delivery of carbon monoxide to be monitored by fluorescence imaging techniques, and thus are useful tools for the study of the biological function of CO.

The catalytic domains of murine Golgi alpha1,2-mannosidases IA and IB that are involved in N-glycan processing were expressed as secreted proteins in P.pastoris . Recombinant mannosidases IA and IB both required divalent cations for activity, were inhibited by deoxymannojirimycin and kifunensine, and exhibited similar catalytic constants using Manalpha1,2Manalpha-O-CH3as substrate. Mannosidase IA was purified as a 50 kDa catalytically active soluble fragment and shown to be an inverting glycosidase. Recombinant mannosidases IA and IB were used to cleave Man9GlcNAc and the isomers produced were identified by high performance liquid chromatography and proton-nuclear magnetic resonance spectroscopy. Man9GlcNAc was rapidly cleaved by both enzymes to Man6GlcNAc, followed by a much slower conversion to Man5GlcNAc. The same isomers of Man7GlcNAc and Man6GlcNAc were produced by both enzymes but different isomers of Man8GlcNAc were formed. When Man8GlcNAc (Man8B isomer) was used as substrate, rapid conversion to Man5GlcNAc was observed, and the same oligosaccharide isomer intermediates were formed by both enzymes. These results combined with proton-nuclear magnetic resonance spectroscopy data demonstrate that it is the terminal alpha1, 2-mannose residue missing in the Man8B isomer that is cleaved from Man9GlcNAc at a much slower rate. When rat liver endoplasmic reticulum membrane extracts were incubated with Man9GlcNAc2, Man8GlcNAc2was the major product and Man8B was the major isomer. In contrast, rat liver Golgi membranes rapidly cleaved Man9GlcNAc2to Man6GlcNAc2and more slowly to Man5GlcNAc2. In this case all three isomers of Man8GlcNAc2were formed as intermediates, but a distinctive isomer, Man8A, was predominant. Antiserum to recombinant mannosidase IA immunoprecipitated an enzyme from Golgi extracts with the same specificity as recombinant mannosidase IA. These immunodepleted membranes were enriched in a Man9GlcNAc2to Man8GlcNAc2-cleaving activity forming predominantly the Man8B isomer. These results suggest that mannosidases IA and IB in Golgi membranes prefer the Man8B isomer generated by a complementary mannosidase that removes a single mannose from Man9GlcNAc2.

This article describes a peer support project developed and carried out by a group of experienced mental health professionals, organized to offer peer psychological support from overseas to healthcare professionals on the frontline of the COVID-19 outbreak in Wuhan, China. This pandemic extremely challenged the existing health care systems and caused severe mental distress to frontline healthcare workers. The authors describe the infrastructure of the team and a novel model of peer support and crisis intervention that utilized a popular social media application on smartphone. Such a model for intervention that can be used elsewhere in the face of current global pandemic, or future disaster response.