6 research outputs found

    Emergence of complexity inhierarchically organized chiral particles

    No full text
    The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. While empirical observations of complex nanoassemblies are abundant, physicochemical mechanisms leading to their geometrical complexity are still puzzling, especially for non-uniformly sized components. Here we report the assembly of hierarchically organized particles (HOPs) with twisted spikes and other morphologies from polydisperse Au-Cys nanoplatelets. The complexity of Au-Cys HOPs is higher than biological counterparts or other complex particles as enumerated by graph theory methods. Their intricate organization emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. These findings and HOPs phase diagrams open a pathway to a large family of colloids with complex architectures and unusual chiroptical and chemical properties

    L’attività dei Centri Antifumo italiani tra problematiche e aree da potenziare: i risultati di un’indagine svolta attraverso un questionario on-line

    No full text
    Introduzione. In Italia sono 295 i Servizi per la cessazione dal fumo di tabacco (Centri Antifumo - CA) afferenti al Servizio Sanitario Nazionale (SSN) censiti nel 2011 dall’Osservatorio Fumo, Alcol e Droga (OssFAD) dell’Istituto Superiore di SanitĂ . La presente indagine, condotta dall’OssFAD in collaborazione con i CA, Ăš stata volta a rilevare alcune delle problematiche con le quali il personale dei CA si confronta per portare avanti la propria attivitĂ  e le iniziative ritenute utili per migliorarla. Materiali e metodi. L’indagine Ăš stata condotta dal 7 al 21 maggio 2012, mediante un questionario compilabile on-line composto da 5 brevi sezioni di domande con un totale di 38 items da completare. Il link al questionario on-line Ăš stato inviato per e-mail a 322 indirizzi dei CA censiti nel 2011 dall’OssFAD. I dati raccolti sono stati elaborati statisticamente con il programma SPSS 20. Risultati. All’indagine hanno risposto 146 operatori dei CA (45,3%). Sebbene ci siano aspetti ormai consolidati dell’attivitĂ  dei CA, sono ancora molte le criticitĂ  che gli operatori riscontrano nella loro attivitĂ . Le principali problematiche che influiscono in modo fondamentale/rilevante per la buona attivitĂ  del centro sono le “Scarse o nulle risorse economiche” per il 60,7% del personale, “la mancanza di personale dedicato” per il 52,4% del personale; il “riconoscimento/mandato istituzionale del CA” per il 40,9% del personale. Tra le azioni ritenute piĂč efficaci per facilitare l’accesso ai CA sono risultate la sensibilizzazione del personale sanitario (91%), in particolare dei medici di famiglia e l’inserimento delle prestazioni antitabagiche nei LEA (76,8%). Conclusioni. È auspicabile che l’attivitĂ  dei CA riceva una maggiore attenzione, attraverso la dotazione di strutture, personale e finanziamenti adeguati a svolgere un importante ruolo nella tutela e promozione della salute

    Outcomes from elective colorectal cancer surgery during the SARS‐CoV‐2 pandemic

    Get PDF
    Aim This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic. Method This was an international cohort study of patients undergoing elective resection of colon or rectal cancer without preoperative suspicion of SARS-CoV-2. Centres entered data from their first recorded case of COVID-19 until 19 April 2020. The primary outcome was 30-day mortality. Secondary outcomes included anastomotic leak, postoperative SARS-CoV-2 and a comparison with prepandemic European Society of Coloproctology cohort data. Results From 2073 patients in 40 countries, 1.3% (27/2073) had a defunctioning stoma and 3.0% (63/2073) had an end stoma instead of an anastomosis only. Thirty-day mortality was 1.8% (38/2073), the incidence of postoperative SARS-CoV-2 was 3.8% (78/2073) and the anastomotic leak rate was 4.9% (86/1738). Mortality was lowest in patients without a leak or SARS-CoV-2 (14/1601, 0.9%) and highest in patients with both a leak and SARS-CoV-2 (5/13, 38.5%). Mortality was independently associated with anastomotic leak (adjusted odds ratio 6.01, 95% confidence interval 2.58–14.06), postoperative SARS-CoV-2 (16.90, 7.86–36.38), male sex (2.46, 1.01–5.93), age >70 years (2.87, 1.32–6.20) and advanced cancer stage (3.43, 1.16–10.21). Compared with prepandemic data, there were fewer anastomotic leaks (4.9% versus 7.7%) and an overall shorter length of stay (6 versus 7 days) but higher mortality (1.7% versus 1.1%). Conclusion Surgeons need to further mitigate against both SARS-CoV-2 and anastomotic leak when offering surgery during current and future COVID-19 waves based on patient, operative and organizational risks

    Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic.

    Get PDF
    BACKGROUND: Surgical services are preparing to scale up in areas affected by COVID-19. This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery. METHODS: This international cohort study included adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020. Patients suspected of SARS-CoV-2 infection before operation were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery. Preoperative testing strategies were adjusted for confounding using mixed-effects models. RESULTS: Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2 per cent) underwent preoperative testing: 1458 (16.6 per cent) had a swab test, 521 (5.9 per cent) CT only, and 324 (3.7 per cent) swab and CT. Pulmonary complications occurred in 3.9 per cent, whereas SARS-CoV-2 infection was confirmed in 2.6 per cent. After risk adjustment, having at least one negative preoperative nasopharyngeal swab test (adjusted odds ratio 0.68, 95 per cent confidence interval 0.68 to 0.98; P = 0.040) was associated with a lower rate of pulmonary complications. Swab testing was beneficial before major surgery and in areas with a high 14-day SARS-CoV-2 case notification rate, but not before minor surgery or in low-risk areas. To prevent one pulmonary complication, the number needed to swab test before major or minor surgery was 18 and 48 respectively in high-risk areas, and 73 and 387 in low-risk areas. CONCLUSION: Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 risk areas. There was no proven benefit of swab testing before minor surgery in low-risk areas

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

    No full text
    corecore