The recent discovery of a hydrolytic enzyme, IsPETase, that can deconstruct poly(ethylene) terephthalate (PET), has sparked great interest in biocatalytic approaches to recycle plastics.Realisation of commercial utility will require the development of robust engineered enzymes that meet the demands of industrial processes. Although rationally engineered variants of PETases have been reported, enzymes that have been experimentally optimised through iterative rounds of directed evolution -the go-to method for engineering industrially useful biocatalysts -have not yet been described. Here, we report the development and implementation of an automated, high-throughput directed evolution platform for engineering polymer degrading enzymes. Evaluation of >IJ,KKK IsPETase variants, applying catalytic activity at elevated temperatures as a primary selection pressure, afforded a HotPETase variant with LI mutations that has a melting temperature of ML.N°C and can therefore operate near or above the glass transition temperature of PET (PK-QK°C).HotPETase can depolymerise semi-crystalline PET more rapidly than previously reported PETases and can selectively deconstruct the PET component of a laminated packaging multi-material. Structural characterisation of HotPETase reveals several interesting features that have emerged during evolution to improve thermotolerance and catalytic performance.Our study establishes laboratory evolution as a platform to engineer useful plastic degrading enzymes to underpin biocatalytic plastic recycling processes.

Of the 596 abstracts found, 8 papers were identified that met the inclusion criteria. A total of 2,208 patients undergoing elective hip and knee arthroplasty were included. Patient satisfaction was reported in 6 papers. Scores were high in all patients and not adversely affected by length of stay. QoL was reported in 2 papers and showed that QoL scores continued to increase up to 12 months following ERAS. Qualitative methods were used in one study, which highlighted problems with support following discharge. There is a paucity of data reporting on patient experience in orthopaedic ERAS. However, ERAS does not compromise patient satisfaction or QoL after elective hip or knee surgery. The measurement of patient experience should be standardised with further research.

IMPORTANCE Complex surgical interventions are inherently prone to variation yet they are not objectively measured. The reasons for outcome differences following cancer surgery are unclear.OBJECTIVE To quantify surgical skill within advanced laparoscopic procedures and its association with histopathological and clinical outcomes. DESIGN, SETTING, AND PARTICIPANTSThis analysis of data and video from the Australasian Laparoscopic Cancer of Rectum (ALaCaRT) and 2-dimensional/3-dimensional (2D3D) multicenter randomized laparoscopic total mesorectal excision trials, which were conducted at 28 centers in Australia, the United Kingdom, and New Zealand, was performed from 2018 to 2019 and included 176 patients with clinical T1 to T3 rectal adenocarcinoma 15 cm or less from the anal verge. Case videos underwent blinded objective analysis using a bespoke performance assessment tool developed with a 62-international expert Delphi exercise and workshop, interview, and pilot phases.INTERVENTIONS Laparoscopic total mesorectal excision undertaken with curative intent by 34 credentialed surgeons.MAIN OUTCOMES AND MEASURES Histopathological (plane of mesorectal dissection, ALaCaRT composite end point success [mesorectal fascial plane, circumferential margin, Ն1 mm; distal margin, Ն1 mm]) and 30-day morbidity. End points were analyzed using surgeon quartiles defined by tool scores. RESULTSThe laparoscopic total mesorectal excision performance tool was produced and shown to be reliable and valid for the specialist level (intraclass correlation coefficient, 0.889; 95% CI, 0.832-0.926; P< .001). A substantial variation in tool scores was recorded (range, 25-48). Scores were associated with the number of intraoperative errors, plane of mesorectal dissection, and short-term patient morbidity, including the number and severity of complications. Upper quartile-scoring surgeons obtained excellent results compared with the lower quartile (mesorectal fascial plane: 93% vs 59%; number needed to treat [NNT], 2.9, P = .002; ALaCaRT end point success, 83% vs 58%; NNT, 4; P = .03; 30-day morbidity, 23% vs 50%; NNT, 3.7; P = .03). CONCLUSIONS AND RELEVANCEIntraoperative surgical skill can be objectively and reliably measured in complex cancer interventions. Substantial variation in technical performance among credentialed surgeons is seen and significantly associated with clinical and pathological outcomes.

There is little information on the optimal technique of perineal wound closure following ELAPE. With the limited data available, there was no significant difference in complication rates between biological mesh and flap repair. There is a need for high-quality prospective trials to compare methods of reconstruction to determine the long-term results, quality of life and function.

There is limited evidence to support decisions regarding when to resect rectal cancer following chemoradiotherapy. There may be benefits in prolonging the interval between chemoradiotherapy and surgery beyond the 6 to 8 weeks that is commonly practiced. However, outcomes need to be studied further in robust randomized studies.