A Multitool for Circular Economy: Fast Ring-Opening Polymerization and Chemical Recycling of (Bio)polyesters Using a Single Aliphatic Guanidine Carboxy Zinc Catalyst.

Invited for this month's cover is the group of Professor Sonja Herres-Pawlis at the RWTH Aachen (Germany). The cover image illustrates the complex yet flexible circular economy of (bio)plastics and the role of a Zn-based catalyst therein. The Research Article itself is available at 10.1002/cssc.202300192.

A Multitool for Circular Economy: Fast Ring-Opening Polymerization and Chemical Recycling of (Bio)polyesters Using a Single Aliphatic Guanidine Carboxy Zinc Catalyst.

A new aliphatic hybrid guanidine N,O-donor ligand (TMGeech) and its zinc chloride complex ([ZnCl2 (TMGeech)]) are presented. This complex displays high catalytic activity for the ring-opening polymerization (ROP) of lactide in toluene, exceeding the toxic industry standard tin octanoate by a factor of 10. The high catalytic activity of [ZnCl2 (TMGeech)] is further demonstrated under industrially preferred melt conditions, reaching high lactide conversions within seconds. To bridge the gap towards a sustainable circular (bio)economy, the catalytic activity of [ZnCl2 (TMGeech)] for the chemical recycling of polylactide (PLA) by alcoholysis in THF is investigated. Fast production of different value-added lactates at mild temperatures is demonstrated. Selective PLA degradation from mixtures with polyethylene terephthalate (PET) and a polymer blend, catalyst recycling, and a detailed kinetic analysis are presented. For the first time, chemical recycling of post-consumer PET producing different value-added materials is demonstrated using a guanidine-based zinc catalyst. Therefore, [ZnCl2 (TMGeech)] is a promising, highly active multitool, not only to implement a circular (bio)plastics economy, but also to tackle today's ongoing plastics pollution.

Closed for business: The mortality impact of business closures during the Covid-19 pandemic.

We investigate the effectiveness of business shutdowns to contain the Covid-19 disease. In March 2020, Italy shut down operations in selected sectors of its economy. Using a difference-in-differences approach, we find that municipalities with higher exposure to closed sectors experienced subsequently lower mortality rates. The implied life savings exceed 9,400 people over a period of less than a month. We also find that business closures exhibited rapidly diminishing returns and had large effects outside the closed businesses themselves, including spillovers to other municipalities. Overall, the results suggest business shutdowns are effective, but should be selectively implemented and centrally coordinated.

Tracking maternal mortality declines in Mongolia between 1992 and 2007: the importance of collaboration.

OBJECTIVE: To describe the declining trend in maternal mortality observed in Mongolia from 1992 to 2007 and its acceleration after 2001 following implementation of the Maternal Mortality Reduction Strategy by the Ministry of Health and other partners. METHODS: We performed a descriptive analysis of maternal mortality data collected through Mongolia's vital registration system and provided by the Mongolian Ministry of Health. The observed declining mortality trend was analysed for statistical significance using simple linear regression. We present the maternal mortality ratios from 1992 to 2007 by year and review the basic components of Mongolia's Maternal Mortality Reduction Strategy for 2001-2004 and 2005-2010. FINDINGS: Mongolia achieved a statistically significant annual decrease in its maternal mortality ratio of almost 10 deaths per 100 000 live births over the period 1992-2007. From 2001 to 2007, the maternal mortality ratio in Mongolia decreased approximately 47%, from 169 to 89.6 deaths per 100 000 live births. CONCLUSION: Disparities in maternal mortality represent one of the major persisting health inequities between low- and high-resource countries. Nonetheless, important reductions in low-resource settings are possible through collaborative strategies based on a horizontal approach and the coordinated involvement of key partners, including health ministries, national and international agencies and donors, health-care professionals, the media, nongovernmental organizations and the general public.