An engineered PET depolymerase to break down and recycle plastic bottles.

Present estimates suggest that of the 359 million tons of plastics produced annually worldwide1, 150-200 million tons accumulate in landfill or in the natural environment2. Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic, with almost 70 million tons manufactured annually worldwide for use in textiles and packaging3. The main recycling process for PET, via thermomechanical means, results in a loss of mechanical properties4. Consequently, de novo synthesis is preferred and PET waste continues to accumulate. With a high ratio of aromatic terephthalate units-which reduce chain mobility-PET is a polyester that is extremely difficult to hydrolyse5. Several PET hydrolase enzymes have been reported, but show limited productivity6,7. Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET). This highly efficient, optimized enzyme outperforms all PET hydrolases reported so far, including an enzyme8,9 from the bacterium Ideonella sakaiensis strain 201-F6 (even assisted by a secondary enzyme10) and related improved variants11-14 that have attracted recent interest. We also show that biologically recycled PET exhibiting the same properties as petrochemical PET can be produced from enzymatically depolymerized PET waste, before being processed into bottles, thereby contributing towards the concept of a circular PET economy.

Embracing diverse worldviews to share planet Earth.

Leading societies toward a more sustainable, equitably shared, and environmentally just future requires elevating and strengthening conversations on the nonmaterial and perhaps unquantifiable values of nonhuman nature to humanity. Debates among conservationists relating to the appropriateness of valuing ecosystems in terms of their human utility have eclipsed the more important and impactful task of expressing conservation concerns in terms that are meaningful to diverse stakeholders. We considered the wide global diversity of perspectives on the biosocial complex-the relationships and interactions between all living species on Earth-and argue that humanity's best chance for effective conservation is to take a pluralistic approach that engages seriously with the worldviews of all stakeholders. Many worldviews-particularly those in indigenous cultures-place a higher value on the spiritual and nonmaterial aspects than what is often represented by the discourse surrounding Western conservation policy. Alternative framings of the biosocial complex that recognize nature's intrinsic value can be powerful motivators for social change and for local-scale conservation efforts. At a national and international level, changing ethical framings of human relationships with nature have started influencing conceptions of human rights relating to the environment and of the rights of nature itself. This change has led to an increased role of the judiciary in promoting environmental sustainability and promoting justice for groups who are most often affected by environmental harms. We hope our essay will motivate the scientific community to change its own perception of what a sound and sustainable relationship between humanity and other species should be and will help citizens become active environmental subjects, connected to the ecosystems around them.

Adopción de Diferentes Cosmovisiones para Compartir el Planeta Tierra Resumen Para poder llevar a las sociedades hacia un futuro sustentable, compartido equitativa y ambientalmente justo se requiere elevar y fortalecer las conversaciones sobre los valores no materiales y probablemente imposibles de cuantificar que la naturaleza no humana tiene para la humanidad. Los debates entre los conservacionistas en relación con lo apropiado que es valorar los ecosistemas en términos de utilidad para los humanos han eclipsado la labor más importante e impactante de expresar los asuntos de conservación en términos que son significativos para diferentes accionistas. Consideramos la amplia diversidad mundial de perspectivas que existen sobre el complejo biosocial - las relaciones e interacciones entre todas las especies vivientes en la Tierra - y argumentamos que la mejor oportunidad que tiene la humanidad para lograr una conservación efectiva es realizar una estrategia pluralística que se comprometa seriamente con las cosmovisiones de todos los accionistas. Muchas cosmovisiones - particularmente aquellas de las culturas indígenas - les otorgan un valor más alto a los aspectos espirituales y no materiales que lo que se suele representar en el discurso que rodea la política de conservación occidental. Los marcos alternativos del complejo biosocial que reconocen el valor intrínseco de la naturaleza pueden ser motivadores poderosos para el cambio social y para los esfuerzos de conservación a escala local. A nivel nacional e internacional, el cambio de los marcos éticos de las relaciones humanas con la naturaleza ha comenzado a influenciar las concepciones de los derechos humanos en relación con el ambiente y los derechos de la naturaleza misma. Este cambio ha resultado en un papel mucho mayor del poder judicial en la promoción de la sustentabilidad ambiental y de la justicia para grupos a los que con frecuencia les afectan los daños ambientales. Esperamos que nuestro ensayo motive a la comunidad científica a cambiar su propia percepción de lo que debe ser una relación sana y sustentable entre la humanidad y otras especies y que ayude a los ciudadanos a volverse sujetos ambientales más activos y conectados con el ecosistema.

National multicentric evaluation of quality of pathology reports for rectal cancer in France in 2016.

The quality of pathologic assessment of rectal cancer specimens is crucial for treatment efficiency and survival. The Royal College of Pathologists (RCP) recommends evaluating the quality of the pathology report in routine practice using three quality indicators (QIs): the number of lymph nodes (LNs) analyzed (≥ 12), the rate of venous invasion (VI ≥ 30%), and peritoneal involvement (pT4a ≥ 10%). In this study, we evaluated the three QIs of the French national pathology reports and compared them with British guidelines and assessed the influence of neoadjuvant radiochemotherapy on QIs. From January 1 to December 31, 2016, all pathology reports for rectal adenocarcinoma were collected from French departments. Neoadjuvant radiochemotherapy included long-course radiotherapy with concomitant 5-FU-based chemotherapy. A total of 983 rectal cancer pathology reports were evaluated. A median of 15 LNs were analyzed and 81% of centers had ≥ 12 LNs. The rate of VI was 30% and 41% of centers had ≥ 30% VI. The rate of pT4a was 4% and 18% of centers reported ≥ 10% pT4a. None of the centers reached the threshold for the three QIs. All three QIs were lower after radiochemotherapy compared to surgery alone. In conclusion, in French routine practice, the values of two of the three QIs (LNs analyzed and VI) were globally in line with RCP guidelines. However, the rate of pT4a was very low, particularly after radiochemotherapy, suggesting its low value in rectal cancer.