Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

Lanthanum–Cerium-Modified Nickel Catalysts for Dry Reforming of Methane

The catalyst MNi0.9Zr0.1O3 (M = La, Ce, and Cs) was prepared using the sol–gel preparation technique investigated for the dry reforming of methane reaction to examine activity, stability, and H2/CO ratio. The lanthanum in the catalyst LaNi0.9Zr0.1O3 was partially substituted for cerium and zirconium for yttrium to give La0.6Ce0.4Ni0.9Zr0.1−xYxO3 (x = 0.05, 0.07, and 0.09). The La0.6Ce0.4Ni0.9Zr0.1−xYxO3 catalyst’s activity increases with an increase in yttrium loading. The activities of the yttrium-modified catalysts La0.6Ce0.4Ni0.9Zr0.03Y0.07O3 and La0.6Ce0.4Ni0.9Zr0.01Y0.09O3 are higher than the unmodified La0.6Ce0.4Ni0.9Zr0.1O3 catalyst, the latter having methane and carbon dioxide conversion values of 84% and 87%, respectively, and the former with methane and carbon dioxide conversion values of 86% and 90% for La0.6Ce0.4Ni0.9Zr0.03Y0.07O3 and 89% and 91% for La0.6Ce0.4Ni0.9Zr0.01Y0.09O3, respectively. The BET analysis depicted a low surface area of samples ranging from 2 to 9 m2/g. The XRD peaks confirmed the formation of a monoclinic phase of zirconium. The TPR showed that apparent reduction peaks occurred in moderate temperature regions. The TGA curve showed weight loss steps in the range 773 K–973 K, with CsNi0.9Zr0.1O3 carbon deposition being the most severe. The coke deposit on La0.6Ce0.4Ni0.9Zr0.1O3 after 7 h time on stream (TOS) was the lowest, with 20% weight loss. The amount of weight loss increases with a decrease in zirconium loading

Catalytic Performance of Lanthanum Promoted Ni/ZrO2 for Carbon Dioxide Reforming of Methane

Nickel catalysts supported on zirconium oxide and modified by various amounts of lanthanum with 10, 15, and 20 wt.% were synthesized for CO2 reforming of methane. The effect of La2O3 as a promoter on the stability of the catalyst, the amount of carbon formed, and the ratio of H2 to CO were investigated. In this study, we observed that promoting the catalyst with La2O3 enhanced catalyst activities. The conversions of the feed, i.e., methane and carbon dioxide, were in the order 10La2O3 > 15La2O3 > 20La2O3 > 0La2O3, with the highest conversions being about 60% and 70% for both CH4 and CO2 respectively. Brunauer–Emmett–Teller (BET) analysis showed that the surface area of the catalysts decreased slightly with increasing La2O3 doping. We observed that 10% La2O3 doping had the highest specific surface area (21.6 m2/g) and the least for the un-promoted sample. The higher surface areas of the promoted samples relative to the reference catalyst is an indication of the concentration of the metals at the mouths of the pores of the support. XRD analysis identified the different phases available, which ranged from NiO species to the monoclinic and tetragonal phases of ZrO2. Temperature programmed reduction (TPR) analysis showed that the addition of La2O3 lowered the activation temperature needed for the promoted catalysts. The structural changes in the morphology of the fresh catalyst were revealed by microscopic analysis. The elemental compositions of the catalyst, synthesized through energy dispersive X-ray analysis, were virtually the same as the calculated amount used for the synthesis. The thermogravimetric analysis (TGA) of spent catalysts showed that the La2O3 loading of 10 wt.% contributed to the gasification of carbon deposits and hence gave about 1% weight-loss after a reaction time of 7.5 h at 700 °C

Synthesis of Carbon Microspheres from Inedible Crystallized Date Palm Molasses: Influence of Temperature and Reaction Time

In this work, carbon microspheres (CMs) were prepared by hydrothermal carbonization (HTC) of inedible crystallized date palm molasses. The effects of temperature and reaction time on the prepared materials were studied. Experiments were carried out at different temperatures (180, 200, 230 and 250 °C) with reaction times ranging from 2 to 10 h. It was found that temperature had the greatest influence on the mass yield of the CMs. No solid products were observed at a temperature of 180 °C and a reaction time less than 2 h. The highest yield was found to be 40.4% at 250 °C and a reaction time of 6 h. The results show that the CMs produced were approximately 5–9 μm in diameter. The results also show that the largest diameter of the CMs (8.9 μm) was obtained at a temperature of 250 °C and a reaction time of 6 h. Nonetheless, if the reaction time was extended beyond 6 h at 250 °C, the CMs fused and their shapes were deformed (non-spherical shapes). The synthesized materials were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Branuer-Emmett-Teller (BET) and thermogravimetric analysis (TGA). BET surface areas for the four samples were found to be less than 1 m2/g. The methylene blue adsorption studies indicated that the equilibrium adsorption capacity was reached after 15 min, with a maximum adsorption capacity of 12 mg/g. The recycling of date palm molasses (a known processed waste) to generate a useable carbon microsphere represents a beneficial step in the application of sustainable processing industries in the Middle East

Gallium-Promoted Ni Catalyst Supported on MCM-41 for Dry Reforming of Methane

The stability and catalytic activity of mesoporous Ni/MCM-41 promoted with a Ga loading of (0.0, 1.0, 1.5, 2.0, 2.5, and 3.0 wt %) as an innovative catalyst was examined for syngas production via CO2 reforming of CH4. The objective of present work was to develop a potential catalyst for CO2 reforming of methane. For this purpose different loadings of gallium were used to promote 5% nickel catalyst supported on MCM-41. An incipient wetness impregnation method was used for preparing the catalysts and investigated at 800 °C. Physicochemical characterization techniques—including BET, XRD, TPD, TPR, TEM, and TGA—were used to characterize the catalysts. The addition of small amounts of Ga resulted in higher surface areas with a maximum surface area of 1036 m2/g for 2.5% Ga. The incorporation of Ga to the catalyst decreased the medium and strong basic sites and reduced the amount of carbon deposited. There was no weight loss for 3%Ga+5%Ni/MCM-41. The 2% Ga loading showed the highest CH4 conversion of 88.2% and optimum stability, with an activity loss of only 1.58%. The Ga promoter raised the H2/CO ratio from 0.9 to unity

The Effect of Calcination Temperature on Various Sources of ZrO2 Supported Ni Catalyst for Dry Reforming of Methane

Dry reforming of methane (DRM) over an Ni-based catalyst is an innovative research area due to the growing environmental awareness about mitigating global warming gases (CH4 and CO2) and creating a greener route of synthesis. Herein, 5% Ni supported on ZrO2 obtained from various sources was prepared by the impregnation method. The catalysts were calcined at 600, 700, and 800 °C. Furthermore, Ni-RC stabilized with MgO, SiO2, TiO2, and Y2O3 were tested. Characterization techniques employed comprise the N2 physisorption, infrared spectroscopy, Raman, thermogravimetric analysis, XRD, and TEM. The results of the present study indicated that the ZrO2 support source had a profound effect on the overall performance of the process. The best catalyst Ni-RC gave an average conversion of CH4 and CO2 of 61.5% and 63.6% and the least deactivation of 10.3%. The calcination pretreatment differently influenced the catalyst performance. When the average methane conversion was higher than 40%, increasing the calcination temperature decreased the activity. While for the low activity catalysts with an average methane conversion of less than 40% the impact of the calcination temperature did not constantly decrease with the temperature rise. The stabilization of Ni-RC denoted the preference Y2O3 stabilized catalyst with average values of CH4 and CO2 conversion of about 67% and 72%, respectively. The thorough study and fine correlation will be advantageous for technologically suitable Ni-15Y-RC catalysts for DRM

The Effect of Calcination Temperature on Various Sources of ZrO₂ Supported Ni Catalyst for Dry Reforming of Methane

Dry reforming of methane (DRM) over an Ni-based catalyst is an innovative research area due to the growing environmental awareness about mitigating global warming gases (CH4 and CO2) and creating a greener route of synthesis. Herein, 5% Ni supported on ZrO2 obtained from various sources was prepared by the impregnation method. The catalysts were calcined at 600, 700, and 800 °C. Furthermore, Ni-RC stabilized with MgO, SiO2, TiO2, and Y2O3 were tested. Characterization techniques employed comprise the N2 physisorption, infrared spectroscopy, Raman, thermogravimetric analysis, XRD, and TEM. The results of the present study indicated that the ZrO2 support source had a profound effect on the overall performance of the process. The best catalyst Ni-RC gave an average conversion of CH4 and CO2 of 61.5% and 63.6% and the least deactivation of 10.3%. The calcination pretreatment differently influenced the catalyst performance. When the average methane conversion was higher than 40%, increasing the calcination temperature decreased the activity. While for the low activity catalysts with an average methane conversion of less than 40% the impact of the calcination temperature did not constantly decrease with the temperature rise. The stabilization of Ni-RC denoted the preference Y2O3 stabilized catalyst with average values of CH4 and CO2 conversion of about 67% and 72%, respectively. The thorough study and fine correlation will be advantageous for technologically suitable Ni-15Y-RC catalysts for DRM