Conversion Values Research Articles

Comparing a polynomial DOE model and an ANN model for enhanced geranyl cinnamate biosynthesis with Novozym® 435 lipase

Central Composite Rotatable Design (CCRD), a type of factorial design of experiment is among the most traditional methods used for optimizing bioprocesses, but, in recent years artificial neural networks (ANNs) have emerged as a promising approach for data modeling in bioprocesses. A comparative study between CCRD and ANN modeling for data treatment in the optimization of geranyl cinnamate biosynthesis using Novozym® 435 lipase was conducted. The most effective ANN architecture identified for predicting and maximizing the enzymatic synthesis of geranyl cinnamate was a 3-3-1 neurons model utilizing logsig activation function in the hidden layer. The ANN was trained using all available experimental data and demonstrated a strong fit to the experimental data, coefficient of determination near 1 (R2 = 0.9948) and low Sum-squared Error (SSE = 43.06). The polynomial model (CCRD; R2 = 0.9806; SSE = 161.56) indicated the same optimal conditions as the ANN model, predicting a temperature of 90.2 °C, molar ratio of 1:5.68, and enzyme concentration of 18.6% w/w. Comparison of R2 and SSE values due to lack of fit between both models suggests that ANN predictions closely align with experimental conversion values of geranyl cinnamate. Although the polynomial model is feasible to be applied in enzymatic synthesis, it may be less precise in its predictions than ANN models.

Surface engineered sustainable nanocatalyst with improved coke resistance for dry methane reforming to produce hydrogen

The ever-growing carbon-based economy has led to alarming increases in greenhouse gas (GHG) emissions, particularly methane (CH4) and carbon dioxide (CO2). These emissions accelerate global warming, pollution and environmental challenges. Methane Dry Reforming (DRM) offers a promising technology to address this issue by converting CH4 and CO2 into a valuable syngas (CO + H2) mixture, which is a valuable fuel and a building block for many important chemical reactions (Fischer-Tropsch process). However, finding affordable and environmentally friendly catalysts for large-scale applications remains a critical hurdle. This study delves into the development of stable nickel-zirconia catalysts prepared via impregnation method. The weight percentage of nickel and zirconia was varied to optimize the catalyst's activity by controlling deactivation phenomenon that is a major challenge at higher temperatures during DRM. Various characterization techniques (XRD, FT-IR, SEM-EDX, TGA, TEM and BET) were employed to evaluate synthesized catalysts physio-chemical properties. Additionally, catalytic performance was assessed at temperatures ranging from 550 to 750 °C and a gas hourly space velocity (GHSV) of 72,000 mL/h.gcat. Among tested catalysts, 15% Ni/ZrO2 displayed remarkable conversion values for both CH4 (62.9%) and CO2 (64.9%). Importantly, it exhibited significantly lower weight loss (ca. 15.42%) compared to other variants, indicating better resilience against coke deposition. This enhanced stability can be attributed to synergistic interplay between nickel and zirconia support, effectively suppressing carbon formation. These findings demonstrate potential of 15% Ni/ZrO2 as a promising catalyst for experimental DRM application. With the obvious high activity and stability, 15% Ni/ZrO2 candidate serves as an eco-friendly candidate for greenhouse gas conversion into green fuel energy, contributing to a sustainable economy and clean environment.

A New Approach in Lipase-Octyl-Agarose Biocatalysis of 2-Arylpropionic Acid Derivatives.

The use of lipase immobilized on an octyl-agarose support to obtain the optically pure enantiomers of chiral drugs in reactions carried out in organic solvents is a great challenge for chemical and pharmaceutical sciences. Therefore, it is extremely important to develop optimal procedures to achieve a high enantioselectivity of the biocatalysts in the organic medium. Our paper describes a new approach to biocatalysis performed in an organic solvent with the use of CALB-octyl-agarose support including the application of a polypropylene reactor, an appropriate buffer for immobilization (Tris base-pH 9, 100 mM), a drying step, and then the storage of immobilized lipases in a climatic chamber or a refrigerator. An immobilized lipase B from Candida antarctica (CALB) was used in the kinetic resolution of (R,S)-flurbiprofen by enantioselective esterification with methanol, reaching a high enantiomeric excess (eep = 89.6 ± 2.0%). As part of the immobilization optimization, the influence of different buffers was investigated. The effect of the reactor material and the reaction medium on the lipase activity was also studied. Moreover, the stability of the immobilized lipases: lipase from Candida rugosa (CRL) and CALB during storage in various temperature and humidity conditions (climatic chamber and refrigerator) was tested. The application of the immobilized CALB in a polypropylene reactor allowed for receiving over 9-fold higher conversion values compared to the results achieved when conducting the reaction in a glass reactor, as well as approximately 30-fold higher conversion values in comparison with free lipase. The good stability of the CALB-octyl-agarose support was demonstrated. After 7 days of storage in a climatic chamber or refrigerator (with protection from humidity) approximately 60% higher conversion values were obtained compared to the results observed for the immobilized form that had not been stored. The new approach involving the application of the CALB-octyl-agarose support for reactions performed in organic solvents indicates a significant role of the polymer reactor material being used in achieving high catalytic activity.

Performance of sulfided NiMo catalyst supported on pillared bentonite Al and Ti under hydrodeoxygenation reaction of guaiacol

Bio-crude oil is known to be sustainable, eco-environmentally, and an alternative energy source produced by biomass pyrolysis. However, its quality remains relatively low due to a higher oxygen concentration compared to liquid fuels from fossils. Therefore, an upgrading process is necessary through the catalytic hydrodeoxygenation (HDO) process. This work synthesized pillared bentonite using Al and Ti metals as the pillaring agent to produce Al-PILC and Ti-PILC as catalyst support for sulfided NiMo. Their catalytic activity in HDO reaction using guaiacol as a model compound of bio-crude oil were also evaluated. Characterization of the bentonite-pillared materials, including Al-PILC, Mo/Al-PILC, NiMo/Al-PILC, Ti-PILC, Mo/Ti-PILC, and NiMo/Ti-PILC, was performed using Surface Area Analyzer, X-ray Diffractometer (XRD), Temperature-Programmed Desorption of ammonia (NH3-TPD), X-Ray Fluorescence (XRF), and Scanning Electron Microscope (SEM) techniques. The characterization results confirm the pillarization process of bentonite using Al and Ti metals as the pillaring agent, and the preparation of the NiMo catalyst using the stepwise impregnation method was successfully prepared. The NiMo/Ti-PILC catalyst performs a superior conversion value on the HDO guaiacol reaction than other catalysts. A well dispersion of Mo and Ni metals on the surface support (NiMo/Ti-PILC), thus creating numerous active sites of the catalyst after the sulfidation. Variations in time and temperature during the HDO guaiacol reaction significantly affected the conversion.

The short- and long-run environmental value of waste conversion

The short- and long-run environmental value of waste conversion

Selective furfural hydrodeoxygenation over Cu-Fe catalysts with In-Situ Cu@Fe3O4 formation

This study investigates Cu-Fe mixed oxide catalysts with varying Cu/Fe molar ratios (0.5 to 2) synthesized via a sol–gel method for vapor-phase FFR HDO. The catalysts were characterized using XRD, H2-TPR, NH3-TPD, N2 physisorption, FESEM and XPS to gain sights into their properties. The characterizations unveiled the critical role of Cu/Fe molar ratio in influencing the properties and performance of the catalysts in FFR HDO. Fe promoted the dispersion of CuO, especially at a Cu/Fe ratio of 1, revealing synergistic Cu-Fe interactions. Increasing Cu/Fe ratio enhanced the reducibility of Fe but diminished that of Cu. Extensive investigations were conducted to assess the impact of key parameters, including Cu/Fe ratio, temperature, contact time, reduction temperature and H2/FFR molar ratio. The Cu-Fe mixed oxide catalyst with Cu/Fe = 1 proved to the optimal catalyst, exhibiting > 99 % FFR conversion and 90 % 2-MeF selectivity at H2/FFR = 15, 230 °C, and 0.5 gFFR h−1 gcatalyst-1. The extended evaluation of catalytic activity demonstrated sustained high performance, with stable conversion and 2-MeF selectivity values of > 99 % and 90 % over a period of 12 h. Even after 24 h on stream, the conversion remained above 90 %. Subsequent regeneration study showed partial recovery of the activity, with the catalyst maintaining conversion and selectivity consistently at about 85 % and 86 %, respectively for 10 h. Catalyst deactivation was a result of the site and/or pore blockage caused by the adsorption of FFR and FAL as well as the formation of oligomeric compounds on the catalyst’s surface.

A novel and clean technique for the one-pot production of green chemical γ-valerolactone from furfural using bifunctional H3PW12O4/UiO-66 catalyst: Pervaporation membrane reactor

This study focuses on the synthesis of gamma-valerolactone (GVL) from furfural using a bifunctional H3PW12O4-UiO-66 catalyst. The membrane was prepared using PBI polymer. H3PW12O4-UiO-66 catalysts with different amounts of H3PW12O4 were synthesized. The catalytic activity of these synthesized catalysts was investigated in pervaporation membrane reactor to obtain GVL from furfural and the catalyst containing 2 g of H3PW12O4 was identified as the optimum catalyst. After determining the optimum catalyst, the effect of temperature, molar feed ratio, and catalyst concentration on the reaction and separation performance was investigated. The optimum values were determined as 90 °C, molar feed ratio 10 and 6 g/L catalyst concentration by evaluating both reaction and separation performance. The performance of the pervaporation membrane reactor (PVMR) was compared with a batch reactor operated under the same conditions. In the batch reactor operating at 90°C, molar feed ratio of 10, and 6 g/L catalyst concentration, a 65% furfural conversion and 51% GVL yield were obtained, whereas the PVMR achieved 100% furfural conversion and 94.21% GVL yield. This comparison demonstrates the improved efficiency of the PVMR in increasing conversion and yield compared to the traditional batch reactor. The obtained conversion and yield values under the investigated operating conditions highlight the proposed process as a promising alternative for the production of GVL from furfural.

The practical utility of ternary nickel-cobalt-manganese oxide-supported platinum catalysts for room-temperature oxidative removal of formaldehyde from the air

Formaldehyde (FA), a carcinogenic oxygenated volatile organic compound, is present ubiquitously in indoor air. As such, it is generally regarded as a critical target for air quality management. The oxidative removal of FA under dark and room-temperature (RT) conditions is of practical significance. A series of ternary nickel–cobalt-manganese oxide–supported platinum catalysts (Pt/NiCoMnO4) have been synthesized for FA oxidative removal at RT in the dark. Their RT conversion values for 50 ppm FA (XFA) at 5,964 h−1 gas hourly space velocity (GHSV) decrease in the following order: 1 wt% Pt/NiCoMnO4 (100 %) > 0.5 wt% Pt/NiCoMnO4 (25 %) > 0.05 wt% Pt/NiCoMnO4 (14 %) > NiCoMnO4 (6 %). The catalytic performance of 1 wt% Pt/NiCoMnO4 has been examined further under the control of various process variables (e.g., catalyst mass, flow rate, relative humidity, FA concentration, time on stream, and molecular oxygen content). The catalytic oxidation of FA at low temperatures (e.g., RT and 60 °C) is accounted for by Langmuir–Hinshelwood mechanism (single-site competitive-adsorption), while Mars van Krevelen kinetics is prevalent at higher temperatures. In situ diffuse-reflectance infrared Fourier-transform spectroscopy reveals that FA oxidation proceeds through a series of reaction intermediates such as DOM, HCOO–, and CO32–. Based on the density functional theory simulations, the unique electronic structures of the nearest surface atoms (platinum and nickel) are suggested to be responsible for the superior catalytic activity of Pt/NiCoMnO4.

The synthesis of highly nonplanar oxidovanadium(IV) porphyrins as robust catalysts for oxidative bromination of phenols in aqueous medium

Two new complexes, oxidovanadium(IV) 2,3,5,10,12,13,15,20-octaphenyl-7,8,17,18-tetrabromoporphyrin V(IV)O(OPP)Br4 (2), and oxidovanadium(IV) 2,3,5,10,12,13,15,20-octaphenyl-7,8,17,18-tetrachloroporphyrin V(IV)O(OPP)Cl4 (3) starting from oxidovanadium(IV) 2,3,5,10,12,13,15,20-octaphenylporphyrin V(IV)O(OPP) (1) have been prepared in good yields and characterized by various spectroscopic techniques. The single-crystal and DFT-optimized structures of these porphyrins showed a highly nonplanar saddle-shape conformation of the porphyrin macrocycle. In the cyclic voltammograms, the first ring oxidation potential and the first ring reduction potential of V(IV)O(OPP)Br4 (2) and V(IV)O(OPP)Cl4 (3) showed anodic shift as compared to V(IV)O(OPP) (1), indicating the electron-deficient nature of both the porphyrins. The oxidation state of vanadium in the synthesized complexes as +4 was confirmed by EPR spectroscopy, and these porphyrins exhibited axially compressed [Formula: see text] configuration. These porphyrins were utilized as catalysts for the oxidative bromination of thymol and other phenol derivatives with excellent conversion ([Formula: see text] 99.9%), good selectivity, and high TOF value (86869 h[Formula: see text].

Natural magnetite as an effective and long-lasting catalyst for CWPO of azole pesticides in a continuous up-flow fixed-bed reactor

The global occurrence of micropollutants in water bodies has raised concerns about potential negative effects on aquatic ecosystems and human health. EU regulations to mitigate such widespread pollution have already been implemented and are expected to become increasingly stringent in the next few years. Catalytic wet peroxide oxidation (CWPO) has proved to be a promising alternative for micropollutant removal from water, but most studies were performed in batch mode, often involving complex, expensive, and hardly recoverable catalysts, that are prone to deactivation. This work aims to demonstrate the feasibility of a fixed-bed reactor (FBR) packed with natural magnetite powder for the removal of a representative mixture of azole pesticides, recently listed in the EU Watch Lists. The performance of the system was evaluated by analyzing the impact of H2O2 dose (3.6–13.4 mg L−1), magnetite load (2–8 g), inlet flow rate (0.25–1 mL min−1), and initial micropollutant concentration (100–1000 µg L−1) over 300 h of continuous operation. Azole pesticide conversion values above 80% were achieved under selected operating conditions (WFe3O4 = 8 g, [H2O2]0 = 6.7 mg L−1, flow rate = 0.5 mL min−1, pH0 = 5, T = 25 °C). Notably, the catalytic system showed a high stability upon 500 h in operation, with limited iron leaching (< 0.1 mg L−1). As a proof of concept, the feasibility of the system was confirmed using a real wastewater treatment plant (WWTP) effluent spiked with the mixture of azole pesticides. These results represent a clear advance for the application of CWPO as a tertiary treatment in WWTPs and open the door for the scale-up of FBR packed with natural magnetite.

Biodiesel Production by Methanolysis of Rapeseed Oil-Influence of SiO2/Al2O3 Ratio in BEA Zeolite Structure on Physicochemical and Catalytic Properties of Zeolite Systems with Alkaline Earth Oxides (MgO, CaO, SrO).

Alkaline earth metal oxide (MgO, CaO, SrO) catalysts supported on BEA zeolite were prepared by a wet impregnation method and tested in the transesterification reaction of rapeseed oil with methanol towards the formation of biodiesel (FAMEs-fatty acid methyl esters). To assess the influence of the SiO2/Al2O3 ratio on the catalytic activity in the tested reaction, a BEA zeolite carrier material with different Si/Al ratios was used. The prepared catalysts were tested in the transesterification reaction at temperatures of 180 °C and 220 °C using a molar ratio of methanol/oil reagents of 9:1. The transesterification process was carried out for 2 h with the catalyst mass of 0.5 g. The oil conversion value and efficiency towards FAME formation were determined using the HPLC technique. The physicochemical properties of the catalysts were determined using the following research techniques: CO2-TPD, XRD, BET, FTIR, and SEM-EDS. The results of the catalytic activity showed that higher activity in the tested process was confirmed for the catalysts supported on the BEA zeolite characterized by the highest silica/alumina ratio for the reaction carried out at a temperature of 220 °C. The most active zeolite catalyst was the 10% CaO/BEA system (Si/Al = 300), which showed the highest triglyceride (TG) conversion of 90.5% and the second highest FAME yield of 94.6% in the transesterification reaction carried out at 220 °C. The high activity of this system is associated with its alkalinity, high value of the specific surface area, the size of the active phase crystallites, and its characteristic sorption properties in relation to methanol.

CO2 capture through gas hydrate formation in the presence of polyethyleneimine-surface-grafted clay

CO2 capture through gas hydrate formation was performed using a stirring-type vessel in the presence of nanoclay and polyethyleneimine-grafted nanoclay. First, the grafting process was implemented via the wet impregnation method. The nanoparticles were characterized using FT-IR, FESEM, EDS, BET, XRD, TGA, Zeta potential, and DLS analyses. The characterization analyses confirmed surface-grafting of the nanoclay. Then, the hydrate formation experiments were implemented at three various nanoparticle loadings (200, 400, and 500 ppm). Water-to-hydrate conversion, CO2 gas consumption, apparent rate constant, and hydrate storage capacity were obtained and compared. Prior to conducting the CO2 hydrate formation experiments in the presence of nanoparticles, the rocking-type and stirring-type vessels were compared to evaluate the hydrate formation rate (using pure water). Stirring-type vessel exhibited higher hydrate formation rates than rocking-type vessel along with improved gas storage performance which resulted in a 22.4% increase in CO2 consumption. Thus, the effect of additives was examined using the stirring-type vessel. Surface-grafted nanoclay led to higher CO2 consumption compared to nanoclay at all concentrations. Using 500 ppm of modified nanoclay, grafted by 50 mass% polyethyleneimine (PEI) solution as additive, the maximum enhancement of CO2 consumption in the hydrate phase in comparison with pure water was obtained, along with the greatest water to hydrate conversion value (39.67). This study introduces a new technique by modifying nanoclay with PEI to improve CO2 storage in gas hydrate phase, presenting potential advancements in gas storage technology.

Conversion of lignin-derived ketonic intermediate to biofuel products: Syngas-assisted vs. Conventional hydrotreating

A new strategy for the transformation of an intermediate of the lignin conversion process, namely cyclohexanone, to fuel-grade products is assessed in this study. In this regard, the conventional hydrodeoxygenation process (with pure hydrogen) was compared to an innovative one with a simulated lignin-derived syngas stream in a wide range of reaction conditions (300–400 °C, 1–15 bar, and small-to-large feed-to-catalyst ratios) and over commercial molybdenum-based (nickle‑molybdenum (NiMo) and cobalt‑molybdenum(CoMo)) catalysts. Cyclohexanone conversion, product distribution, deoxygenation efficacy, and heating value were compared in each case. Cyclohexanone was transformed into cyclohexane, cyclohexene, benzene, cresols, phenol, toluene, and bi-cyclic compounds, which are beneficial in jet-fuel processing. Increasing the reaction temperature and pressure intensified the conversion of cyclohexanone (up to 87.8% conversion at 400 °C and 15 bar over both NiMo and CoMo catalysts), whereas increasing the feed-to-catalyst ratio reduced it. Operating conditions and the reducing gas (pure hydrogen or syngas) had major impacts on the conversion of cyclohexanone, deoxygenation efficiency, product distribution, and the heating value of the final product blend. The results of this study claim that cyclohexanone conversion to fuel-grade hydrocarbons (up to 97.61% over NiMo and 74.71% over CoMo catalysts) is a beneficial route and the conventional hydrodeoxygenation process can be replaced with the syngas-assisted one with a small change in production capacity, still large positive impact on the sustainability and environmental footprints of lignin conversion to biofuels.

Techno-economic assessment of adsorption processes to recover oxygen from ozonizers

Industrial ozonizers are normally fed with high-purity oxygen and can reach conversions to ozone in the range of 6–15 wt%. Because of these low conversion values, adsorption technology has been proposed to recover most of the unreacted oxygen for recycling to the ozonizer and substantially improve the overall process economics. In this work, it was aimed to design and assess two adsorption processes, a 3-bed 3-step system and a 3-bed, 4-step system, with the purpose of recovering an oxygen stream with a purity of 98.5%, as to not adversely affect the ozonizer performance. Both systems achieved the target oxygen purity with oxygen recoveries >90% for various adsorption pressures ranging 1.5–3.0 bar. Furthermore, an in-depth economic analysis taking into account both CAPEX and OPEX contributions revealed that the 3-bed, 3-step system was marginally more profitable than the 3-bed, 4-step system. Given that the total annualized cost associated with the adsorption systems was considerably lower than the cost of the recovered high-purity oxygen, the integrated ozonizer-adsorption process led to net savings of 85–89% compared to the standalone ozonizer.

Imunitas dan Produktivitas Puyuh Periode Bertelur dengan Pemberian Tepung Daun Senduduk (Melastoma malabathricum L.) dalam Pakan

Senduduk leaf flour (Melastoma malabatricum L.) is a processed product from weed plants that can potentially be a source of nutrients and bioactive compounds that are beneficial for human and livestock health. This research aims to examine the immunity and productivity of quail during the egg-laying period by administering senduduk leaf flour. This study used 120 female quail aged 40 weeks, which were kept for 4 weeks. The experimental design used was a Completely Randomized Design. The treatment of providing senduduk leaf flour in feed consisted of four treatment levels, namely P0 (without flour), P1 (feed + 1.5% flour), P2 (feed + 3% flour), and P3 (feed + 4.5% flour). The data were analyzed using Analysis of Variance and descriptive analysis. The results showed that adding senduduk leaf meal can reduce egg yolk cholesterol and increase quail immunity. Adding senduduk leaf meal at a 3% level produced the best immunity and performance, with a feed conversion value of 2.81. The 4.5% addition of senduduk leaf flour produced the lowest cholesterol level in quail egg yolk. Keywords: egg quality, immunity, performance, quail, senduduk leaf

Kinetic Analysis of Catalytic Dry Reforming of Methane Using Ni-ZrO2/MCM-41 Catalyst

This work investigates the kinetics of catalytic dry reforming of methane (CDRM) to produce hydrogen gas using nickel-based catalysts. A new catalyst was prepared, Ni-ZrO2@MCM-41 (MCMZ) and used in the CDRM reaction. The textural, physical, and morphological scans are used to characterize the prepared catalyst. The performance of the newly prepared catalyst in terms of temperature effects and long-term stability is assessed. The reaction activation energy is studied as well. The outcomes of this study revealed that the MCMZ provided the highest conversion values for CH4 and CO2, with 89 and 91%, respectively. The optimum reaction temperature to achieve the highest syngas conversion was 800 °C. In addition, two new models that present CH4 and CO2 conversions for MCMZ as a function of reaction time to predict the rate of catalyst activity were built with very high accuracy. It was found that the activation energy was within the expected limits. Finally, the constants and reaction rate were determined. To conclude, this research creates a new catalyst with high performance to enhance hydrogen gas production from methane with carbon dioxide that contributes significantly to the field of yielding alternative energy sources.

Nanostructured Pr-Rich CexPr1-xO2-δ Mixed Oxides for Diesel Soot Combustion: Importance of Oxygen Lability.

Soot combustion experiments with 5%O2/He were conducted using model soot, and four distinct compositions of CexPr1-xO2-δ oxides of varying nominal cerium compositions (x = 0, 0.2, 0.3, and 1) were prepared. The catalyst samples were comprehensively characterized using techniques such as XRD, Raman spectroscopy, HR-TEM, N2 adsorption at -196 °C, XPS, O2-TPD, H2-TPR, and work function measurements. The Pr-rich compositions, ranging from Ce0.3Pr0.7O2-δ to PrO2-δ, resulted in a significant increase in the total evolved O2 amounts and enhanced catalyst reducibility. However, a decrease in the textural properties of the catalysts was noted, which was particularly important for the pure praseodymia under the synthesis route conducted. The catalytic activity was investigated under the two following contact modes of mixing between soot and catalyst: loose and tight. The results revealed that the catalytic performance is associated with the surface contact in tight contact mode and with the combination of surface/subsurface/bulk oxygen mobility and the BET surface area in loose contact mode. Notably, the temperatures estimated at 10% and 50% of the conversion (T10 and T50) parameters were achieved at much lower temperatures than the uncatalyzed soot combustion, even under loose contact conditions. Specifically, the 50% conversion was achieved at 511 °C and 538 °C for Ce0.3Pr0.7O2 and Ce0.2Pr0.8O2, respectively. While no direct correlation between catalytic activity and work function was observed, a significant relationship emerges between work function values and the formation of oxygen vacancies, whatever the conditions used for these measurements. On the other hand, the ability to generate a high population of oxygen vacancies at low temperatures, rather than the direct activation of gas-phase O2, influences the catalytic performance of Pr-doped ceria catalysts, highlighting the importance of surface/subsurface oxygen vacancy generation, which was the parameter that showed a better correlation with the catalytic activity, whatever the soot conversion value or the mode of contact considered.

Bio-oxidation of progesterone by Penicillium oxalicum CBMAI 1185 and evaluation of the cytotoxic activity

We report the biotransformation of progesterone 1 by whole cells of Brazilian marine-derived fungi. A preliminary screening with 12 fungi revealed that the strains Penicillium oxalicum CBMAI 1996, Mucor racemous CBMAI 847, Cladosporium sp. CBMAI 1237, Penicillium oxalicum CBMAI 1185 and Aspergillus sydowii CBMAI 935 were efficient in the biotransformation of progesterone 1 in the first days of the reaction, with conversion values ranging from 75 % to 99 %. The fungus P. oxalicum CBMAI 1185 was employed in the reactions in quintuplicate to purify and characterize the main biotransformation products of progesterone 1. The compounds testololactone 1a, 12β-hydroxyandrostenedione 1b and 1β-hydroxyandrostenedione 1c were isolated and characterized by NMR, MS, [α]D and MP. In addition, the chromatographic yield of compound 1a was determined by HPLC-PDA in the screening experiments. In this study, we show a biotransformation pathway of progesterone 1, suggesting the presence of several enzymes such as Baeyer-Villiger monooxygenases, dehydrogenases and cytochrome P450 monooxygenases in the fungus P. oxalicum CBMAI 1185. In summary, the results obtained in this study contribute to the synthetic area and have environmental importance, since the marine-derived fungi can be employed in the biodegradation of steroids present in wastewater and the environment. The cytotoxic results demonstrate that the biodegradation products were inactive against the cell lines, in contrast to progesterone.

Assessment of G10 Intraoperative Scoring System for Conversion in Patients Undergoing Laparoscopic Cholecystectomy: A Cross-Sectional Study From Nepal.

Various preoperative risk factors for conversion in laparoscopic cholecystectomy (LC) have been well studied. However, the assessment of intraoperative factors for conversion in patients with cholecystitis is unclear. The G10 scoring system, which incorporates 10 parameters, has tried to fill this void by developing a scoring system for the most commonly encountered surgical illnesses. So, we aimed to assess the utility of the G10 scoring system among patients presenting for LC for symptomatic cholelithiasis (both acute and chronic cholecystitis) in the clinical setting of a low- and middle-income country. All the patients undergoing LC were assigned a G10 value. Gallbladder surgery was considered easy if the G10 score was <2, moderate (2 ≦ 4), difficult (5 ≦ 7), and extreme (8 ≦ 10). All 10 risk factors were analyzed into a binary logistics model, and statistically significant risk factors were assessed. Among 177 patients, there were 36 males and 141 females. The median age of the patient was 42 years (range 11-79). There were 70 easy, 89 moderate, and 18 difficult cases. The overall mean G10 score was 2.32±1.5, which significantly increased as the severity progressed, with a mean value of 5.5±0.51 for difficult cases(P=0.0001). The mean G10 score for surgeries completed laparoscopically was 2.1±1.4, while it was 3.71±1.4 for open conversions[P=0.0001, AUC=0.79, CI=0.70-0.87]. There were 18 patients with G10 ≥5 with a conversion rate of 27.7%, while the overall conversion rate was 13.6%. Multivariate analysis showed free bile or pus outside the gallbladder [P=0.02, OR=5.1, CI=1.2-21.1] and fistula [P=0.01, OR=15.8, CI=1.9-129.8] as significant risk factors for conversion. Intraoperative risk factors for the prediction of conversion included the presence of free bile or pus outside the gallbladder and cholecystoenteric fistula. Based on the F1 score analysis, complemented with the Youden Index, the optimal cutoff value for conversion, based on the G10 score, lies around 4. Broader application and validation of the G10 scoring system are mandated to assess the utilization of this novel intraoperative scoring system.

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines.

In this investigation, coal fines enriched with inertinite were used for direct liquefaction experiments. For comparison, a vitrinite-rich coal typically utilized in coal-to-liquid processes was also employed. To assess the impact of mineral matter content, demineralization was used to remove most of the inorganic constituents. The findings revealed that the inertinite-rich coal exhibited lower liquefaction conversions due to a reduced proportion of reactive macerals and elevated levels of inorganic mineral matter. These conversion values exhibited a strong correlation with the quantity of reactive macerals present in the parent coals. For the inertinite-rich coal, the presence of inorganic mineral matter impeded the liquefaction process but facilitated the CO2 gasification reactions of the derived chars. To evaluate their potential in gasification processes, CO2 gasification experiments were conducted and the reactivities and apparent gasification activation energies of both coal chars, liquefaction residue chars, and preasphaltene and asphaltene (PAA) chars were calculated. These calculations were carried out using the random pore model (RPM) and volumetric reaction model (VRM). The chemistry, reactivity, and kinetics of residue gasification conversion are not thoroughly understood, yet they hold significant importance in optimizing syngas production within gasification processes. The findings from this work highlight significant differences in liquefaction conversion values, product distribution, and composition. These differences are influenced by factors such as maceral composition, inorganic mineral matter content, hydrogen-donor capabilities of the solvent, and liquefaction reaction temperatures. Additionally, these variables affect the CO2 gasification reactivity of liquefaction solid residue chars.