Estudo da molhabilidade e das propriedades anticorrosivas de recobrimentos finos de PTFE-like/Al2O3 sobre aço carbono

O estudo da eficiência de recobrimentos que apresentam propriedades anti-corrosivas, quando aplicados em materiais metálicos, torna-se importante no ponto de vista acadêmico e industrial. Com esse intuito, foram sintetizadas amostras de aço carbono 1020 recobertas com alumina e Politetrafluoroetileno (PTFE), depositados por Radio Frequency Sputtering (RFSputtering), para o estudo das propriedades anticorrosivas e molhabilidade. A presença da alumina mostrou-se essencial frente aos estudos iniciais com silano, assim como uma afinidade sinérgica com o PTFE. Os resultados das propriedades anticorrosivas indicaram resultados promissores. A resistência à transferência de carga aumentou de 3,12 kΩcm², considerando a amostra sem recobrimento, para 101 kΩcm², para a amostra recoberta com alumina e com PTFE-like depositado por 45 minutos e os resultados das resistências dos recobrimentos, com a inserção do PTFE-like sobre a alumina subiram de 0,24 kΩcm², considerando somente o recobrimento de alumina, para 51,4 kΩcm², considerando a amostra recoberta com alumina e PTFE-like depositado por 45 minutos, quando em contato com solução durante 0,25h. Os valores de capacitância, simulados por circuito elétrico equivalente, diminuíram até duas ordens de grandeza com a inserção dos recobrimentos. As capacitâncias de dupla camada e de recobrimento caíram de 216 µFcm-2 (amostra nua) e 330 µFcm-2 (recoberta com alumina) para 1,25 µFcm-2 (recoberta com alumina e PTFE-like depositado por 15 minutos) e 2,29 µFcm-2 (recoberta com alumina e PTFE-like depositado por 30 min), respectivamente. Esses resultados indicaram uma efetiva proteção à corrosão. Os fatores que contribuíram para a proteção do substrato foram as barreiras físicas interpostas entre substrato e eletrólito e também a baixa molhabilidade, que está associada a uma baixa energia livre de Gibbs, em que os ângulos de contato Os fatores que contribuíram para a proteção do substrato foram as barreiras físicas interpostas entre substrato e eletrólito e também a baixa molhabilidade, que está associada a uma baixa energia livre de Gibbs, em que os ângulos de contato aumentaram de 90±2°, considerando a amostra sem recobrimento, para 120±2° para a amostra recoberta com alumina e PTFE-like depositado por 45 minutos. Esse aumento resultou em menos interações entre líquido/sólido. Comparando com relatos na literatura, os recobrimentos desse trabalho, tendo em conta sua resistência relativa do recobrimento por unidade de espessura, alcançaram eficiências de duas a três ordens de grandeza maiores na proteção a superfícies de aço carbono.The study of efficiency of coatings that present anti-corrosion properties, when applied to metallic surfaces, becomes is important in the academic and industrial perspectives. For that purpose, samples of commercial 1020 carbon steel coated with alumina and PTFE-like were deposited by RF-Sputtering for anti-corrosion and wettability studies, performed by Electrochemical Impedance Spectroscopy (EIS) and the Sessile drop method, respectively. Studies of morphology and topology were also performed by SEM, XPS and AFM. The insertion of the alumina coating was important, in comparison to silane, as well as to its synergistic affinity with PTFE. The charge transfer and coating resistances increased from 3.12 kΩcm² (bare steel) and 0.24 kΩcm² (alumina coating) to 101.0 kΩcm² and 51.4 kΩcm², for the sample coated with alumina and PTFE-like deposited for 45 minutes, respectively. The double layer and coatings capacitances for the coated samples, simulated by the equivalent electric circuit approach, decrease in comparison to bare steel up to two orders of magnitude. These results indicate an effective corrosion protection. The physical barrier provided by coatings and their low wettability also contributed to the corrosion protection, since contact angles increased from 90±2°, for the uncoated sample, to 120±2° for the sample coated with alumina and PTFE-like deposited for 45 minutes, resulting in less interaction in the liquid/solid interface. In comparison to literature reports, these coatings achieved efficiency two to three orders of magnitude higher in relative coating resistance, per thickness unit, in carbon steel surface protection

Double layer SiO2–TiO2 sol–gel thin films on glass for antireflection, antifogging, and UV recoverable self-cleaning

Double layer thin films, mechanically stable and adhering to glass, were produced through the sol–gel process, using tetraethyl orthosilicate and titanium butoxide as precursors. The refractive index of the titania and silica– titania composite layers were typically 2.1 and 1.7, and their physical thicknesses were approximately 65 nm and 81 nm, respectively, as determined by ellipsometry. These optical constants allowed attainment of quarterwave optical thicknesses at the center of the visible spectrum (550 nm) as designed, with an increase of 3.4% in transmittance. The nanometric surface roughness, measured by optical profilometry, was effective to decrease light scattering and water contact angles to below 10◦ . As novelty in dip-coated sol–gel films, superhydrophilicity for self-cleaning, antifogging, and antireflection in the mid-visible spectrum were simultaneously attained with durability of 9 weeks in the dark. Further application of UV light allowed regeneration of contact angles for self-cleaning

Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

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

Hotspots of biogeochemical activity linked to aridity and plant traits across global drylands

14 páginas.- 4 figuras.- 67 referencias.- The online version contains supplementary material available at https://doi.org/10.1038/s41477-024-01670-7Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown. Here we evaluated the relative importance of grazing pressure and herbivore type, climate and plant functional traits on 24 soil physical and chemical attributes that represent proxies of key ecosystem services related to decomposition, soil fertility, and soil and water conservation. To do this, we conducted a standardized global survey of 288 plots at 88 sites in 25 countries worldwide. We show that aridity and plant traits are the major factors associated with the magnitude of plant effects on fertile islands in grazed drylands worldwide. Grazing pressure had little influence on the capacity of plants to support fertile islands. Taller and wider shrubs and grasses supported stronger island effects. Stable and functional soils tended to be linked to species-rich sites with taller plants. Together, our findings dispel the notion that grazing pressure or herbivore type are linked to the formation or intensification of fertile islands in drylands. Rather, our study suggests that changes in aridity, and processes that alter island identity and therefore plant traits, will have marked effects on how perennial plants support and maintain the functioning of drylands in a more arid and grazed world.This research was supported by the European Research Council (ERC grant 647038 (BIODESERT) awarded to F.T.M.) and Generalitat Valenciana (CIDEGENT/2018/041). D.J.E. was supported by the Hermon Slade Foundation (HSF21040). J. Ding was supported by the National Natural Science Foundation of China Project (41991232) and the Fundamental Research Funds for the Central Universities of China. M.D.-B. acknowledges support from TED2021-130908B-C41/AEI/10.13039/501100011033/Unión Europea Next Generation EU/PRTR and the Spanish Ministry of Science and Innovation for the I + D + i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. O.S. was supported by US National Science Foundation (Grants DEB 1754106, 20-25166), and Y.L.B.-P. by a Marie Sklodowska-Curie Actions Individual Fellowship (MSCA-1018 IF) within the European Program Horizon 2020 (DRYFUN Project 656035). K.G. and N.B. acknowledge support from the German Federal Ministry of Education and Research (BMBF) SPACES projects OPTIMASS (FKZ: 01LL1302A) and ORYCS (FKZ: FKZ01LL1804A). B.B. was supported by the Taylor Family-Asia Foundation Endowed Chair in Ecology and Conservation Biology, and M. Bowker by funding from the School of Forestry, Northern Arizona University. C.B. acknowledges funding from the National Natural Science Foundation of China (41971131). D.B. acknowledges support from the Hungarian Research, Development and Innovation Office (NKFI KKP 144096), and A. Fajardo support from ANID PIA/BASAL FB 210006 and the Millennium Science Initiative Program NCN2021-050. M.F. and H.E. received funding from Ferdowsi University of Mashhad (grant 39843). A.N. and M.K. acknowledge support from FCT (CEECIND/02453/2018/CP1534/CT0001, SFRH/BD/130274/2017, PTDC/ASP-SIL/7743/2020, UIDB/00329/2020), EEA (10/CALL#5), AdaptForGrazing (PRR-C05-i03-I-000035) and LTsER Montado platform (LTER_EU_PT_001) grants. O.V. acknowledges support from the Hungarian Research, Development and Innovation Office (NKFI KKP 144096). L.W. was supported by the US National Science Foundation (EAR 1554894). Y.Z. and X.Z. were supported by the National Natural Science Foundation of China (U2003214). H.S. is supported by a María Zambrano fellowship funded by the Ministry of Universities and European Union-Next Generation plan. The use of any trade, firm or product names does not imply endorsement by any agency, institution or government. Finally, we thank the many people who assisted with field work and the landowners, corporations and national bodies that allowed us access to their land.Peer reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Estudo da molhabilidade e das propriedades anticorrosivas de recobrimentos finos de PTFE-like/Al2O3 sobre aço carbono

O estudo da eficiência de recobrimentos que apresentam propriedades anti-corrosivas, quando aplicados em materiais metálicos, torna-se importante no ponto de vista acadêmico e industrial. Com esse intuito, foram sintetizadas amostras de aço carbono 1020 recobertas com alumina e Politetrafluoroetileno (PTFE), depositados por Radio Frequency Sputtering (RFSputtering), para o estudo das propriedades anticorrosivas e molhabilidade. A presença da alumina mostrou-se essencial frente aos estudos iniciais com silano, assim como uma afinidade sinérgica com o PTFE. Os resultados das propriedades anticorrosivas indicaram resultados promissores. A resistência à transferência de carga aumentou de 3,12 kΩcm², considerando a amostra sem recobrimento, para 101 kΩcm², para a amostra recoberta com alumina e com PTFE-like depositado por 45 minutos e os resultados das resistências dos recobrimentos, com a inserção do PTFE-like sobre a alumina subiram de 0,24 kΩcm², considerando somente o recobrimento de alumina, para 51,4 kΩcm², considerando a amostra recoberta com alumina e PTFE-like depositado por 45 minutos, quando em contato com solução durante 0,25h. Os valores de capacitância, simulados por circuito elétrico equivalente, diminuíram até duas ordens de grandeza com a inserção dos recobrimentos. As capacitâncias de dupla camada e de recobrimento caíram de 216 µFcm-2 (amostra nua) e 330 µFcm-2 (recoberta com alumina) para 1,25 µFcm-2 (recoberta com alumina e PTFE-like depositado por 15 minutos) e 2,29 µFcm-2 (recoberta com alumina e PTFE-like depositado por 30 min), respectivamente. Esses resultados indicaram uma efetiva proteção à corrosão. Os fatores que contribuíram para a proteção do substrato foram as barreiras físicas interpostas entre substrato e eletrólito e também a baixa molhabilidade, que está associada a uma baixa energia livre de Gibbs, em que os ângulos de contato Os fatores que contribuíram para a proteção do substrato foram as barreiras físicas interpostas entre substrato e eletrólito e também a baixa molhabilidade, que está associada a uma baixa energia livre de Gibbs, em que os ângulos de contato aumentaram de 90±2°, considerando a amostra sem recobrimento, para 120±2° para a amostra recoberta com alumina e PTFE-like depositado por 45 minutos. Esse aumento resultou em menos interações entre líquido/sólido. Comparando com relatos na literatura, os recobrimentos desse trabalho, tendo em conta sua resistência relativa do recobrimento por unidade de espessura, alcançaram eficiências de duas a três ordens de grandeza maiores na proteção a superfícies de aço carbono.The study of efficiency of coatings that present anti-corrosion properties, when applied to metallic surfaces, becomes is important in the academic and industrial perspectives. For that purpose, samples of commercial 1020 carbon steel coated with alumina and PTFE-like were deposited by RF-Sputtering for anti-corrosion and wettability studies, performed by Electrochemical Impedance Spectroscopy (EIS) and the Sessile drop method, respectively. Studies of morphology and topology were also performed by SEM, XPS and AFM. The insertion of the alumina coating was important, in comparison to silane, as well as to its synergistic affinity with PTFE. The charge transfer and coating resistances increased from 3.12 kΩcm² (bare steel) and 0.24 kΩcm² (alumina coating) to 101.0 kΩcm² and 51.4 kΩcm², for the sample coated with alumina and PTFE-like deposited for 45 minutes, respectively. The double layer and coatings capacitances for the coated samples, simulated by the equivalent electric circuit approach, decrease in comparison to bare steel up to two orders of magnitude. These results indicate an effective corrosion protection. The physical barrier provided by coatings and their low wettability also contributed to the corrosion protection, since contact angles increased from 90±2°, for the uncoated sample, to 120±2° for the sample coated with alumina and PTFE-like deposited for 45 minutes, resulting in less interaction in the liquid/solid interface. In comparison to literature reports, these coatings achieved efficiency two to three orders of magnitude higher in relative coating resistance, per thickness unit, in carbon steel surface protection

Estudo das propriedades estruturais e ópticas de vidros teluritos do sistema TeO2-Li2O-Nb2O5

Os vidros teluritos são materiais que apresentam importantes propriedades ópticas de interesse aplicativo na área da fotônica. Uma das propriedades interessantes de tal vidro é o elevado índice de refração. De acordo com estudos realizados, o incremento de óxidos modificadores de rede nos vidros teluritos provoca o aumento do índice de refração em tal material, devido à mudanças estruturais ocorridas. Com esse intuito, sintetizamos amostras de vidros teluritos com nióbio, de composição 80TeO2-(20-x)Li2O-xNb2O5 (x = 0, 5, 10 e 15). Para caracterização das amostras foram realizadas medidas de espectroscopia na região do infravermelho (FTIR) e UV-Vis, espectroscopia Raman e Difratometria de Raios-X. Foram realizadas medidas de índice de refração das amostras para verificar a influência da concentração de óxido de nióbio acerca deste índice. A difratometria de Raios-X confirmou o estado amorfo das amostras. Os estudos de caracterização (por espectroscopia no infravermelho e Raman) mostraram que a inserção de óxido de nióbio deslocou, para maiores freqüências, as bandas de absorção características dos grupos TeO4 e NbO4 provocadas por mudanças estruturais e pela incorporação de oxigênios não-ligantes. A espectroscopia na região ultravioleta-visível mostrou uma tendência no aumento do comprimento de onda de corte com o acréscimo de óxido de nióbio, o qual pode estar associado a alguma mudança estrutural. As medidas de índice de refração mostraram que, de acordo com o incremento de óxidos modificadores, este índice aumentou. Tal fato se deve à transição de oxigênios nãoligantes para ligantes e à polarização das ligações Te–O dos grupos TeO4 e ligações Nb–O dos grupos NbO4, pois essas ligações apresentam maiores momentos de dipolo elétrico que as demais.Tellurite glasses are important materials which have interesting optical properties application in photonics mainly due to its high refractive index. According to studies, the increase of network modifier oxides in tellurite glasses can increase the refractive index in such material, due to structural changes. For this purpose, samples with niobium tellurite glasses of composition 80TeO2-(20-x)Li2O-xNb2O5 (x = 0, 5, 10 and 15) were synthesized and characterized by (FTIR) and UV-Vis spectroscopy, Raman spectroscopy and X-ray diffraction. The influence of niobium oxide concentration to the refractive index was also investigated. The characterization studies (infrared spectroscopy and Raman) showed that the insertion of niobium oxide shifted the characteristic absorption bands of groups TeO4 and NbO4 to higher frequencies. The structural changes are due to incorporation of non-bridging oxygen. The UV-Vis spectra showed a trend of increasing the wavelength of UV-Vis cut-off with the addition of niobium oxide and this increase may be linked to structural changes. The X-ray diffraction confirmed the amorphous state of samples. The measurement of refractive index showed that, in accordance with the increment of oxide modifiers, this index increased. This is due to the transition from non-bridging oxygen to bridging oxygen and the polarization of the Te-O bonds of the groups TeO4 and links Nb-O of the NbO4 groups because these bonds have higher dipole moments than the others