56 research outputs found

    Study of the Interaction of Heavy Metals (Cu(II), Zn(II)) Ions with a Clay Soil of the Region of Naima-Tiaret-Algeria

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    The RM (RM stands for the pristine clay) collected from sites in the Naima-Tiaret-Algeria and its purified phase TM (TM stands for the treated clay) were characterized using XRF, XRD, FT−IR, SEM−EDX, and DC electrical conductivity techniques. The as-prepared clays were used as potential adsorbents for the removal of Cu2+ and Zn2+ metals ions. Highly purified clay TM, exhibiting a basal, spacing of 25.83 Å and CEC of 51 meq/100 g, was obtained. The type of interstratified I/M in the studied sites is S=1, based on the calculation method of Watanabe. The percentage of illite type S=1 is between 80−85% illite. The adsorption equilibrium was established in 60 min with the capacities of 28.57 and 24.39 mg/g for Cu2+ onto RM, 32.25 and 4.95 mg/g for Zn2+ in the presence of TM. D-R isotherm model was more suitable with the adsorption process than Freundlich and Langmuir models suggesting the ion exchange nature of the retention mechanism in most cases (E > 8 kJ/mol). Pseudo second-order model best described the kinetics of adsorption process. The adsorption mechanism was mainly monitored by ion exchange mechanism between exchangeable interlayer cations (Na) in the interstratified I/M and Cu2+ or Zn2+ metals from aqueous matrix. Further, the release of H+ ions from the edge of the layer structure in acidic environments promote the adsorption of heavy metals onto the surfaces interstratified I/M clay soils via electrostatic attraction. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

    Contribution to the Study of the Relation between Microstructure and Electrochemical Behavior of Iron-Based FeCoC Ternary Alloys

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    This work deals with the relation between microstructure and electrochemical behavior of four iron-based FeCoC ternary alloys. First, the arc-melted studied alloys were characterized using differential thermal analyses and scanning electron microscopy. The established solidification sequences of these alloys show the presence of two primary crystallization phases (δ(Fe) and graphite) as well as two univariante lines : peritectic L + δ(Fe)↔γ(Fe) and eutectic L↔γ(Fe) + Cgraphite. The ternary alloys were thereafter studied in nondeaerated solution of 10−3 M NaHCO3 + 10−3 M Na2SO4, at 25°C, by means of the potentiodynamic technique. The results indicate that the corrosion resistance of the FeCoC alloys depends on the carbon amount and the morphology of the phases present in the studied alloys

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

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

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    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

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

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    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.

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    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

    Therapeutic effect of nanosecond pulsed electric fields on murine model of colorectal peritoneal metastasis

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    Ce travail doctoral a pour but d'évaluer la sensibilité des cellules CT-26 murines de cancer colorectal (CCR) à des impulsions de 10 nanosecondes, à haute fréquence et haute intensité (nsPEF). Après avoir développé un modèle de souris de métastases péritonéales coliques (MPc), nous avons étudié la réponse histologique in vivo selon une nouvelle classification (Peritoneal Regression Grading Score) spécifique des MPc. La fibrose a été analysée par microscopie multiphotonique, la prolifération (KI67, DAPI) et l'expression des facteurs immunologiques (CD3, CD4, CD8) par histologie classique. Nous avons démontré que les nsPEFs exercent un effet dose-réponse sur les cellules CT-26 et dans le modèle murin de MPc, en induisant la mort cellulaire et en modifiant la morphologie des mitochondries après perméabilisation de la membrane plasmique. De plus, une réponse immunitaire spécifique des lymphocytes T CD8 +, ainsi qu'une forte réponse histologique viennent renforcer l’effet anti-tumoral des nsPEFs. Ainsi, ces impulsions nanosecondes semblent être une alternative thérapeutique à confirmer dans des études expérimentales afin notamment d’en évaluer son innocuité sur le péritoine sain et d’améliorer l’ergonomie du système d’application.The aim of this study was to evaluate the sensitivity of murine colorectal cancer (CRC) CT-26 cells to 10 ns pulses, at high frequency and high intensity (nsPEF). We have developed a mouse model of colorectal peritoneal metastasis (PMc) and the histological response was then assessed according to a new classification (Peritoneal Regression Grading Score). Fibrosis was analyzed by multiphoton microscopy, proliferation (KI67, DAPI) and expression of immunological factors (CD3, CD4, CD8) by classical histology. We have demonstrated that nsPEFs display a dose-response effect on CT-26 cells by inducing cell death and plasma membrane permeabilization, as well as altering mitochondria morphology. In addition, a specific immune response (CD8+ T lymphocytes) and a major histological response have confirmed the potentiality of nsPEFs as an anti-tumor therapeutic alternative. We still need to evaluate the innocuity of nsPEFs on healthy peritoneum and the ergonomics of the application system are challenging to be improved

    Effets thérapeutiques des champs électriques pulsés nanosecondes sur modèle murin de métastates péritonéales coliques

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    The aim of this study was to evaluate the sensitivity of murine colorectal cancer (CRC) CT-26 cells to 10 ns pulses, at high frequency and high intensity (nsPEF). We have developed a mouse model of colorectal peritoneal metastasis (PMc) and the histological response was then assessed according to a new classification (Peritoneal Regression Grading Score). Fibrosis was analyzed by multiphoton microscopy, proliferation (KI67, DAPI) and expression of immunological factors (CD3, CD4, CD8) by classical histology. We have demonstrated that nsPEFs display a dose-response effect on CT-26 cells by inducing cell death and plasma membrane permeabilization, as well as altering mitochondria morphology. In addition, a specific immune response (CD8+ T lymphocytes) and a major histological response have confirmed the potentiality of nsPEFs as an anti-tumor therapeutic alternative. We still need to evaluate the innocuity of nsPEFs on healthy peritoneum and the ergonomics of the application system are challenging to be improved.Ce travail doctoral a pour but d'évaluer la sensibilité des cellules CT-26 murines de cancer colorectal (CCR) à des impulsions de 10 nanosecondes, à haute fréquence et haute intensité (nsPEF). Après avoir développé un modèle de souris de métastases péritonéales coliques (MPc), nous avons étudié la réponse histologique in vivo selon une nouvelle classification (Peritoneal Regression Grading Score) spécifique des MPc. La fibrose a été analysée par microscopie multiphotonique, la prolifération (KI67, DAPI) et l'expression des facteurs immunologiques (CD3, CD4, CD8) par histologie classique. Nous avons démontré que les nsPEFs exercent un effet dose-réponse sur les cellules CT-26 et dans le modèle murin de MPc, en induisant la mort cellulaire et en modifiant la morphologie des mitochondries après perméabilisation de la membrane plasmique. De plus, une réponse immunitaire spécifique des lymphocytes T CD8 +, ainsi qu'une forte réponse histologique viennent renforcer l’effet anti-tumoral des nsPEFs. Ainsi, ces impulsions nanosecondes semblent être une alternative thérapeutique à confirmer dans des études expérimentales afin notamment d’en évaluer son innocuité sur le péritoine sain et d’améliorer l’ergonomie du système d’application

    Effets thérapeutiques des champs électriques pulsés nanosecondes sur modèle murin de métastates péritonéales coliques

    No full text
    The aim of this study was to evaluate the sensitivity of murine colorectal cancer (CRC) CT-26 cells to 10 ns pulses, at high frequency and high intensity (nsPEF). We have developed a mouse model of colorectal peritoneal metastasis (PMc) and the histological response was then assessed according to a new classification (Peritoneal Regression Grading Score). Fibrosis was analyzed by multiphoton microscopy, proliferation (KI67, DAPI) and expression of immunological factors (CD3, CD4, CD8) by classical histology. We have demonstrated that nsPEFs display a dose-response effect on CT-26 cells by inducing cell death and plasma membrane permeabilization, as well as altering mitochondria morphology. In addition, a specific immune response (CD8+ T lymphocytes) and a major histological response have confirmed the potentiality of nsPEFs as an anti-tumor therapeutic alternative. We still need to evaluate the innocuity of nsPEFs on healthy peritoneum and the ergonomics of the application system are challenging to be improved.Ce travail doctoral a pour but d'évaluer la sensibilité des cellules CT-26 murines de cancer colorectal (CCR) à des impulsions de 10 nanosecondes, à haute fréquence et haute intensité (nsPEF). Après avoir développé un modèle de souris de métastases péritonéales coliques (MPc), nous avons étudié la réponse histologique in vivo selon une nouvelle classification (Peritoneal Regression Grading Score) spécifique des MPc. La fibrose a été analysée par microscopie multiphotonique, la prolifération (KI67, DAPI) et l'expression des facteurs immunologiques (CD3, CD4, CD8) par histologie classique. Nous avons démontré que les nsPEFs exercent un effet dose-réponse sur les cellules CT-26 et dans le modèle murin de MPc, en induisant la mort cellulaire et en modifiant la morphologie des mitochondries après perméabilisation de la membrane plasmique. De plus, une réponse immunitaire spécifique des lymphocytes T CD8 +, ainsi qu'une forte réponse histologique viennent renforcer l’effet anti-tumoral des nsPEFs. Ainsi, ces impulsions nanosecondes semblent être une alternative thérapeutique à confirmer dans des études expérimentales afin notamment d’en évaluer son innocuité sur le péritoine sain et d’améliorer l’ergonomie du système d’application
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