A Versatile Platform to Generate Shell-Cross-Linked Uniform Π-Conjugated Nanofibers with Controllable Length, High Morphological Stability, and Facile Surface Tailorability.

Living crystallization-driven self-assembly (CDSA) has emerged as an efficient route to generate π-conjugated-polymer-based nanofibers (CPNFs) with promising applications from photocatalysis to biomedicine. However, the lack of efficient tools to endow CPNFs with morphological stability and surface tailorability becomes a frustrating hindrance for expanding application spectrum of CPNFs. Herein, a facile strategy to fabricate length-controllable OPV-based (OPV = oligo(p-phenylenevinylene)) CPNFs containing a cross-linked shell with high morphological stability and facile surface tailorability through the combination of living CDSA and thiol-ene chemistry by using OPV5 -b-PNAAM32 (PNAAM = poly(N-allyl acrylamide)) as a model is reported. Uniform fiber-like micelles with tunable length can be generated by self-seeding of living CDSA. By taking advantage of radical thiol-ene reaction between vinyls of PNAAM corona and four-arm thiols, the shell of micelles can be cross-linked with negligible destruction of structure of vinylene-containing OPV core. The resulting micelles show high morphological stability in NaCl solution and PBS buffer, even upon heating at 80 °C. The introduced extra thiol groups in the cross-linked shell can be further employed to install extra functional moieties via convenient thiol-Michael-type reaction. Given the negligible cytotoxicity of resulting CPNFs, this strategy opens an avenue to fabricate various CPNFs of diverse functionalities for biomedicine.

Optimal group testing strategy for the mass screening of SARS-CoV-2.

We analyze the group testing strategy that maximizes the efficiency of the SARS-CoV-2 screening test while ensuring its effectiveness, where the effectiveness of group testing guarantees that negative results from pooled samples can be considered presumptive negative. Two aspects of test efficiency are considered, one concerning the maximization of the welfare throughput and the other concerning the maximization of the identification rate (namely, identifying as many infected individuals as possible). We show that compared with individual testing, group testing leads to a higher probability of false negative results but a lower probability of false positive results. To ensure the test effectiveness, both the group size and the prevalence of SARS-CoV-2 must be below certain respective thresholds. To achieve test efficiency that concerns either the welfare throughput maximization or the identification rate maximization, the optimal group size is jointly determined by the test accuracy parameters, the infection prevalence rate, and the relative importance of identifying infected subjects. We also show that the optimal group size that maximizes the welfare throughput is weakly smaller than the one that maximizes the identification rate.

Effects of resistance exercise on blood glucose level and pregnancy outcome in patients with gestational diabetes mellitus: a randomized controlled trial.

INTRODUCTION: To date, the effects of resistance exercise on diabetes-related parameters (blood glucose level and insulin use) and pregnancy outcome in participants with gestational diabetes mellitus (GDM) have not been compared with those of aerobic exercise. To investigate the effect of resistance exercise versus aerobic exercise on blood glucose level, insulin utilization rate, and pregnancy outcome in patients with GDM. RESEARCH DESIGN AND METHODS: From December 2019 to December 2020, 100 pregnant women with GDM were selected and divided into a resistance exercise group (49 patients) and an aerobic exercise group (51 patients) randomly. The aerobic exercise group received an aerobic exercise intervention, while the resistance exercise group received a resistance exercise intervention. Both groups received exercise intervention for 50-60 min, 3 times per week, lasting for 6 weeks. In addition, patients in both groups received the same routine care, including personalized dietary intervention, online education, and school courses for pregnant women. RESULTS: The blood glucose level in the resistance exercise group and the aerobic exercise group was lower after the intervention than before the intervention (p<0.05). After the intervention, no significant differences were observed in the fasting blood glucose level, insulin utilization rate, and incidence of adverse pregnancy outcomes between the two groups (p>0.05); however, significant differences were noted in 2-hour postprandial blood glucose level and exercise compliance between the two groups (p<0.05), with the resistance exercise group showing better outcomes than the aerobic exercise group. CONCLUSIONS: Resistance exercise is more compliant for pregnant women with GDM than aerobic exercise; hence, it is necessary to popularize resistance exercise in this specific population group. Long-term effects of resistance exercise should be evaluated in future studies. TRIAL REGISTRATION NUMBER: ChiCTR 1900027929.

Deoxyfluorination of Carboxylic Acids with CpFluor: Access to Acyl Fluorides and Amides.

3,3-Difluoro-1,2-diphenylcyclopropene (CpFluor), a bench-stable fluorination reagent, has been developed in the deoxyfluorination of carboxylic acids to afford various acyl fluorides. This all-carbon-based fluorination reagent enabled the efficient transformation of (hetero)aryl, alkyl, alkenyl, and alkynyl carboxylic acids to the corresponding acyl fluorides under the neutral conditions. This deoxyfluorination method was featured by the synthesis of acyl fluorides with in-situ formed CpFluor, as well as the one-pot amidation reaction of carboxylic acids via in-situ formed acyl fluorides.