Structural variation, dynamics, and catalytic application of palladium(II) complexes of di-N-heterocyclic carbene-amine ligands

A series of palladium(II) complexes incorporating di-NHC-amine ligands has been prepared and their structural, dynamic and catalytic behaviour investigated. The complexes [trans-(k(2)-(CN)-C-tBu(Bn)CN(Bn)C-tBu)PdCl2] (12) and [trans-(kappa(2)-(CN)-C-Mes(H)C-Mes)PdCl2] (13) do not exhibit interaction between the amine nitrogen and palladium atom respectively. NMR spectroscopy between - 40 and 25 degrees C shows that the di-NHC-amine ligand is flexible expressing C-s symmetry and for 13 rotation of the mesityl groups is prevented. In the related C-1 complex [(kappa(3)-(CN)-C-tBu(H)C-tBu)PdCl][CI] (14) coordination of NHC moieties and amine nitrogen atom is observed between -40 and 25 degrees C. Reaction between 12 - 14 and two equivalents of AgBF4 in acetonitrile gives the analogous complexes [trans-(kappa(2)-(CN)-C-tBu(Bn)C-tBu)PdCl2] (12) and [trans-(kappa(CN)-C-2Mes(H)C-Mes)PdCl2] (13) do not exhibit interaction between the amine nitrogen and palladium atom respectively. NMR spectroscopy between -40 ans 25 degrees C shows the di-NHC-amine ligand is flexible expressing C-s symmetry and for 13 rotation of the mesityl groups is prevented. In the related C-1 complex [kappa(3)-(CN)-C-tBu(H)C-tBu)PdCI][CI] (14) coordination of NHC moieties and amine nitrogen atom is observed between -40 and 25 degrees C.Reaction between 12-14 and two equivalents of AgBF4 in acetonitrile gives the analogous complexes [trans-(kappa(2)-(CN)-C-tBu(H)(CPd)-Pd-tBu(MeCN)(2)][BF4](2) (15), [trans-(kappa(CN)-C-2Mes(H)C-Mes)Pd(MeCN)(2)[BF4](2 (16)) and [(kappa(3)-(CN)-C-tBu(H)C-tBu)Pd(MeCN)][BF4](2) (17) indicating that ligand structure determines amine coordination. The single crystal X-ray structures of 12, 17 and two ligand imidazolium salt precursors C-tBu(H)N(Bn)C(H) (tBu)][CI](2) (2) and [C-tBu(H) N(H)C(H)(tBu)][BPh4](2) (4) have been determined. Complexes 12-14 and 15-17 have been shown to be active precatalysts for Heck and hydroamination reactions respectively

Mortality and pulmonary complications in patients undergoing surgery with perioperative sars-cov-2 infection: An international cohort study

Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p<00001), age 70 years or older versus younger than 70 years (230 [165-322], p<00001), American Society of Anesthesiologists grades 3-5 versus grades 1-2 (235 [157-353], p<00001), malignant versus benign or obstetric diagnosis (155 [101-239], p=0046), emergency versus elective surgery (167 [106-263], p=0026), and major versus minor surgery (152 [101-231], p=0047). Interpretation Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Caracterización mecánica de la madera en rollo delgada de pino laricio, clasificada visualmente

This work reports the mechanical characterization of small-diameter logs (diameter < 23 cm) of laricio pine (Pinus nigra subsp. Saltzmannii) from the forests of Cuenca, Spain. Some 445 machine-rounded small logs with final diameters of 8, 10, 12 and 14 cm were examined in accordance with the standard EN 14251, and the conclusion reached that ungraded material can be assigned a strength class of C14 (according to EN 338), while graded material can be assigned to different combinations of strength classes (C18/C14 or C20/C16) depending on the visual grading standard used. Grading yields were examined using three different standards, DIN 4074, VPS-SRT-2 and prEN 14544, and the results obtained with each compared to those provided by the optimal ranking methodology set out in standard EN 14081-2. VPS-SRT-2 appeared to be the most suitable visual grading standard. There is a need to design mixed grading methods based on the use of non-destructive tests and the visual evaluation of specific wood features.En el presente trabajo se presentan los resultados de la caracterización mecánica efectuada sobre madera en rollo delgada (diámetro inferior a 23 cm) de pino laricio (Pinus nigra subsp. Saltzmannii) procedente de los Montes de Cuenca, España. Se ensayaron, de acuerdo con la norma EN 14251, un total de 445 rollizos torneados con diámetros finales de 8, 10, 12 y 14 cm, concluyéndose que el material sin clasificar puede ser asignado a una clase de resistencia de C14 (según EN 338), mientras que el clasificado puede ser asignado a diversas combinaciones de clases de resistencia (C18/C14 ó C20/C16) en función de la norma de clasificación empleada. Se analizó el rendimiento clasificatorio y la asignación de clases de resistencia a clases de calidad obtenidas empleando tres normas de clasificación visual: DIN 4074, VPS-SRT-2 y prEN 14544. Los resultados obtenidos con cada norma de clasificación visual, expresados en forma de rendimientos clasificatorios, fueron confrontados con los obtenidos mediante la metodología de la "Clasificación Óptima" contenida en la norma EN 14081-2. Se concluye sobre la superioridad de la norma VPSSRT-2, así como sobre la necesidad de proceder a diseñar métodos mixtos de clasificación basados en el empleo de técnicas de ensayo no destructivas y de evaluación visual de determinados caracteres