Methyl Research Articles

Synthesis, Properties, and Techno-economic Analysis of Highly Stable Biotransformer Oil Derived from Transesterification of Palm Oil Methyl Esters and Ditrimethylolpropane.

Currently, biotransformer oil (BTO) is in high demand due to the increasing level of electrical power consumption and environmental policy. Hence, this research aimed to prepare a highly stable BTO via basic transesterification of palm oil methyl ester (POME) and ditrimethylolpropane (Di-TMP) catalyzed by sodium methoxide (NaOCH3). Under the optimal conditions (POME/Di-TMP molar ratio = 5.0/1.0, NaOCH3 loading = 8 mol % based on the Di-TMP content under 3.5 mbar, and 300 rpm at 160 °C for 2 h), the POME conversion level and POME-Di-TMPTTE selectivity reached 90.3% and 96.6%, respectively. The obtained BTO with a high POME-Di-TMPTTE portion exhibited greater oxidation stability with a higher flash point and breakdown voltage in accordance with the IEC 62770 specification. A techno-economic analysis revealed the possibility of POME-Di-TMPTTE as a commercial BTO for its competitive cost and profit based on the current commercial price of BTO.

Semi-continuous cultivation of microalgae to treat coal mine effluent in pilot scale: Nutrient removal, biodesalination and fatty acid composition analysis

Coal excavation is associated with discharge of an enormous amount of mine water rich in salt and trace metal ions, which require efficient treatment before use. Considering the potentiality of microalgae for high salt tolerance, salt removal and metallic pollutant removal from aqueous system, present study focuses semi-continuous cultivation of candidate microalgae Chlorella pyrenoidosa (NCIM 2738) in bubble column reactor (BCR) and open raceway pond (ORP) for nutrient supplemented coal mine effluent (NSCME) treatment. In between different hydraulic retention times (HRTs), HRT 6 d provide maximum average biomass productivity of 950 mg L−1 d−1 in BCR and 728.4 mg L−1 d−1 in ORP. HRT 9 d facilitates a maximum lipid content of 1.8 g L ̶ 1 in BCR and 1.4 g L ̶ 1 in ORP. Further, HRT 9 d had the maximum COD removal efficiency (96.5 % in BCR and 94.2 % in ORP) and maximum salinity removal efficiency (93 % in BCR and 92 % in ORP). Fatty acid methyl esters (FAME) characterization highlighted potential biodiesel applicability with cetane number (CN) of 53.94. Energy dispersive X-ray spectroscopy (EDS) revealed an excess amount of salt and metal ions deposition on the surface of harvested microalgae samples. Outdoor large-scale C. pyrenoidosa cultivation can be integrated with coal mine closure plans to meet sustainable development goals (SDGs) 6, 7 and 13.

Techno-economic assessment of co-production of biodiesel and epoxy fatty acid methyl ester as renewable fuel and plasticizer from waste cooking oil

Diversifying waste cooking oil (WCO)-based biodiesel production towards epoxy fatty acid methyl esters (EFAMEs) offers a double gain, boosting revenue channels in the biodiesel sector and driving the development of sustainable phthalate plasticizer alternatives. This study explored the techno-economic feasibility of co-derived biodiesel and EFAMEs from WCO using a three-step process involving enzymatic transesterification, urea complexation, and performic acid epoxidation. The result shows that a plant processing 61,300 tonnes/year of WCO, may produce ∼27,770 tonnes/year of biodiesel and ∼30,180 tonnes/year of EFAMEs, with a total heating duty of 1,124 kW and annual electricity consumption of 34.9 million kWh. The initial capital investment of the plant in China amounts to 136.8 MM CNY, with an annual manufacturing cost of 460 MM CNY in 2022. Techno-economic evaluation demonstrats a net present value (NPV) of 421.9 MM CNY at a 10 % discount rate, an internal rate of return (IRR) of 37.69 %, and discounted payback period of 2.37 years. The break-even point (BEP) is estimated at an annual sales volume of total products of 27,101 tonnes/year, including 12,790, 11,769, 2,542, and 2,390 tonnes/year of epoxy plasticizers, biodiesel, glycerol, and polymeric grease, respectively, collectively utilizing 42.38 % of the processing capacity. Monte Carlo simulation indicates minimal risk of the project, with probabilities of 98.5 % for IRR > 10 % and 97.8 % for a positive NPV. This study affirms the economic viability of co-producing biodiesel and EFAMEs from WCO for industrial application.

Unveiling Nanoscale Ordering in Amorphous Semiconducting Polymers Using Four-Dimensional Scanning Transmission Electron Microscopy.

We present four-dimensional (4D) scanning transmission electron microscopy (STEM) analysis to obtain a high level of detail regarding the nanoscale ordering within largely disordered organic semiconducting polymers. Understanding nanoscale molecular ordering in semiconducting polymers is crucial due to its connection to the materials' important properties. However, acquiring such information in a spatially localized manner has been limited by the lack of a nanoscale experimental probe, weak signal from ordering, and radiation damage to the sample. By collecting nanodiffraction patterns with a high dynamic range pixelated detector, we acquired statistically robust, high signal-to-noise ratio diffraction patterns from semiconducting organic materials, including poly(3-hexylthiophene-2,5-diyl) (P3HT), P3HT/[6,6]-phenyl C61 butyric acid methyl ester, and indacenodithiophene-co-benzothiadiazole (IDTBT), which largely have disordered structures. Real-space images of the ordered domains were reconstructed from the 4D-STEM data set for a variety of scattering vectors and in-plane angles to capture the different molecular stacking distances and their in-plane orientation. These were then analyzed to obtain the average size of the ordered domains within the sample. Such measurements were arranged in a two-dimensional (2D) histogram, which showed a direct relationship between the type and size of molecular ordering. Complementary analyses, such as intensity variance and angular correlation, were applied to obtain ordering and symmetry information. These analyses enabled us to directly characterize the alkyl and π-π stacking of P3HT, as well as the fullerene domains caused by donor segregation in the P3HT sample. Furthermore, the analysis also captured changes in the P3HT domains when the fullerenes are incorporated. Lastly, IDTBT showed a much lesser degree of ordering without much disinclination between the domains within the 2D histogram. The 4D-STEM analysis that we report here unveils new details of molecular ordering that can be used to optimize the properties of this important class of materials.

Integrating environmental remediation with biodiesel production from toxic non-edible oil seeds (Croton bonplandianus) using a sustainable phyto-nano catalyst

In the current situation of the environmental uprising toxicology, rising global temperature, and energy-depleting urges to explore and discover more renewable and greener ecological-benefiting energy resources. Biobased renewable fuels generated by using waste products can help in waste management, climate change mitigation, and a low-carbon future. The main objective of this research is to produce environment-friendly and cost-effective biofuel. The potentiality of the novel, toxic, waste, and inedible feedstock Croton bonplandianus was evaluated for biodiesel synthesis through transesterification utilizing a Phyto-nano catalyst of potassium oxide prepared by Croton bonplandianus floral stalk's aqueous extract focusing on waste management. Phyto-nano catalyst characterization was done through innovative tools such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Zeta Potential (ZP), X-Ray Diffraction (XRD), Fourier Transformed Infrared spectroscopy (FTIR), and Diffuse Reflectance Spectroscopy (DRS). The characterization results revealed that the potassium oxide phyto-nanocatalyst possesses an average nanoparticle size of 44.5 nm. This size is optimal for enhanced catalytic activity, indicating significant potential for efficient catalysis. The highest yield (94 %) of biodiesel was secured at optimized reaction conditions of catalyst quantity (0.50 wt%), reaction time (180 min), methanol: oil ratio (9:1), and reaction thermal point (70 °C). Transformation of triglycerides to methyl esters was confirmed by GC/MS, NMR, and FTIR techniques. A total of 21 methyl esters were observed in Croton bonplandianus biodiesel confirmed via GC/MS results. Evaluation of fuel properties was done and matched with international fuel standards. The conclusive remarks for the conducted research are that Croton bonplandianus has a high potential for biodiesel production by applying Phyto-nanocatalysts of potassium oxide while dealing with hazardous environmental conditions and waste management. Phyto nanocatalyst of potassium oxide can be reused and gives the same yield after several cycles of reusability, this reusability of heterogenous Phyto nanocatalyst can reduce to total cost of biodiesel production and can contribute towards circular economy.

Effect of 4,4′-dialkyl-2,2′-bipyridine ligands on the hydrolysis of dichlorodioxomolybdenum(VI) catalyst precursors and the switch from homogeneous epoxidation to heterogeneous systems

Molybdenum catalysts have been industrially recognized for decades for liquid phase epoxidation, which is an important chemical reaction process, since epoxides are used for many industrial applications. In this work, molybdenum oxide hybrid catalysts, prepared by a reflux hydrolysis methodology, performed effectively as heterogeneous catalysts or reaction-induced self-separating catalysts under mild reaction conditions; in the two cases, the catalyst separation and reuse are facilitated. Specifically, catalysts with the general formula [MoO3(L)], possessing polymeric chain-like (L = 4,4′-dimethyl-2,2′-bipyridine (1)) or oligomeric (L = 4,4′-dinonyl-2,2′-bipyridine (2)) structures comprising corner-sharing {MoO4N2} units, were synthesized and characterized by various complementary techniques (ATR FT-IR, Raman, 13C{1H} CP MAS NMR spectroscopy, PXRD, SEM, TGA, elemental analysis, ICP-OES and N2 sorption isotherms). Small chemical differences in the organic synthesis precursor had important structure directing effects on the type of hybrid material formed. The hybrids promoted olefin epoxidation with H2O2 or tert-butylhydroperoxide (TBHP) as oxidant. For example, 1 catalyzed the conversion of biobased olefins (70 °C) and lignin-based isoeugenol (50 °C) with TBHP to useful bioproducts, in heterogeneous phase, leading to an epoxide yield of 100 % for DL-limonene (3:1 M molar ratio of 1,2-epoxy-p-menth-8-ene to 1,2:8,9-diepoxy-p-menthane), 81 % epoxide yield for fatty acid methyl esters, and 80 % Licarin A selectivity at 40 % isoeugenol conversion. For dienes (DL-limonene, methyl linoleate), kinetic modelling studies suggested that the formation of the monoepoxides was faster than that of diepoxides, accounting for enhanced monoepoxide selectivity.

Biodiesel from Higher Alcohols for Removal of Crude Oil Spills from Coastal Sediments

Throughout the decades, the production, transport, and use of fossil fuels have led to numerous environmental concerns. Crude oil has caused catastrophic accidents after its spillage into the aqueous environment and accumulation on coastal sediments. To tackle this problem in a sustainable manner, researchers have used alternative remediation agents to extract these crude oil spills from the sediments. In this study, the biodiesels fatty acid methyl, ethyl, and butyl esters (FAME, FAEE, and FABE, respectively) were synthesized via transesterification reaction from waste cooking oil and corresponding alcohol in the presence of a catalyst, potassium hydroxide, and used as remediation agents for crude oil extraction. The influence of different experimental conditions on the crude-oil removal efficiency was studied (time of 1, 2, or 4 h; mass ratio of biodiesel to crude oil of 0.5:1, 1:1, or 2:1), with a simulation of coastal effects using a shaker. UV/Vis spectrophotometry was used to determine crude-oil separation efficiency based on the correlation of the residual crude-oil mass fraction and corresponding absorbance. The results show that FAME and FAEE were most effective in the removal of crude oil from sand (removing 88–89%), while FAEE and FABE extracted the most crude oil from gravel (removing 74–77%).

Online characterization of primary and secondary emissions of particulate matter and acidic molecules from a modern fleet of city buses

Abstract. The potential impact of transitioning from conventional fossil fuel to a non-fossil-fuel vehicle fleet was investigated by measuring primary emissions via extractive sampling of bus plumes and assessing secondary mass formation using the Gothenburg Potential Aerosol Mass (Go:PAM) reactor from 76 in-use transit buses. Online chemical characterization of gaseous and particulate emissions from these buses was conducted using chemical ionization mass spectrometry (CIMS) with acetate as the reagent ion, coupled with the Filter Inlet for Gases and AEROsols (FIGAERO). Acetate reagent ion chemistry selectively ionizes acidic compounds, including organic and inorganic acids, as well as nitrated and sulfated organics. A significant reduction (48 %–98 %) in fresh particle emissions was observed in buses utilizing compressed natural gas (CNG), biodiesels like rapeseed methyl ester (RME) and hydrotreated vegetable oil (HVO), and hybrid-electric HVO (HVOHEV) compared to diesel (DSL). However, secondary particle formation from photooxidation of emissions was substantial across all the fuel types. The median ratio of particle mass emission factors of aged to fresh emissions increased in the following order: DSL buses at 4.0, HVO buses at 6.7, HVOHEV buses at 10.5, RME buses at 10.8, and CNG buses at 84. Of the compounds that can be identified by CIMS, fresh gaseous emissions from all Euro V/EEV (Enhanced Environmentally friendly Vehicle) buses, regardless of fuel type, were dominated by nitrogen-containing compounds such as nitrous acid (HONO), nitric acid (HNO3), and isocyanic acid (HNCO), alongside small monoacids (C1−C3). Notably, the emission of nitrogen-containing compounds was lower in Euro VI buses equipped with more advanced emission control technologies. Secondary gaseous organic acids correlated strongly with gaseous HNO3 signals (R2=0.85–0.99) in Go:PAM, but their moderate to weak correlations with post-photooxidation secondary particle mass suggest that they are not reliable tracers of secondary organic aerosol formation from bus exhaust. Our study highlights that non-regulated compounds and secondary pollutant formation, not currently addressed in legislation, are crucial considerations in the evaluation of environmental impacts of future fuel and engine technology shifts.

Quercus ballot as an innovative feedstock for biodiesel production using ZnO nanocatalyst

Selecting non-edible plant seed oil remains the best choice for biodiesel production using an effective nanocatalyst. In this study, the ZnO was prepared as a nanocatalyst using an aqueous extract from the Alhaji marorum plant. Nano ZnO has shown high catalytic activity, is cost-effective, environmentally friendly and converts triglycerides into fatty acid methyl esters. The results indicate that ZnO nanocatalyst exhibit a high specific surface area (146.82 m2 g-1), large pore volume (0.35 cm3 g-1), and an average crystallite size of 42.3 nm. The FESEM analysis shows that the particle size of ZnO lies in the range of 30–50 nm with a rod shape and densely packed morphology. The biodiesel is produced using a transesterification process from novel non-edible Quercus ballot plant seeds. The resulting biodiesel has a 98.06 % yield under a methanol/oil ratio of 6:1 with 0.5 wt% ZnO nanocatalyst at 65 °C for 80 min. It is established that the methanol-to-oil ratio and the catalyst concentration significantly affect the transesterification reaction. The biodiesel produced is characterized by GC–MS to determine its exact composition and FTIR is used to confirm functional groups and is evaluated according to ASTM D6751.

Synthesis of Azabicyclic Isosteres of Piperazine 2S-Carboxylic Acid.

Methods have been developed for the stereocontrolled synthesis of bicyclic diaza [3.3.0] octane carboxylic acids as possible isosteres of piperazine 2S-carboxylic acid. In the first approach, l-pyroglutamic acid was functionalized adopting new as well as documented reaction sequences via Michael and aza-Michael reactions, leading to two of the four intended isosteres. An alternative shorter route relying on enolate chemistry starting with N-Pf 4-keto l-proline methyl ester led to two other isosteres. Calculated pKa values and density functional theory (DFT) calculations have provided some insights into the relative basicities of the nitrogen atoms in these diaza [3.3.0] octane carboxylic acids in relation to piperazine 2S-carboxylic acid.

Circulation process of methyl ester production from pretreated sludge palm oil using CaO/ABS catalytic static mixer coupled with an ultrasonic clamp

This study investigates the potential of fused deposition modeling (FDM) three-dimensional (3D) printing techniques for manufacturing catalytic static mixers during biodiesel synthesis. The printed catalytic mixing elements comprises acrylonitrile butadiene styrene (ABS) plastic with 15 wt% calcium oxide (CaO) as a solid catalyst. When the reactants flowed through the CaO/ABS mixing device, the blending and acceleration processes were both significantly impacted. Moreover, their characteristics, performance in biodiesel production, reusability, and economy were analyzed. The effects of methanol to oil (M:O) molar ratio, circulation time, and sonication time on methyl ester (ME) purity were also examined. The results showed that CaO crystals were distributed on the CaO/ABS mixer’s surface, which is crucial for catalytic purposes. During circulation process of ME from pretreated sludge palm oil (PSPO), catalytic static mixer (CSM) and CSM coupled with ultrasound (CSM/US) reactors were employed. The full ultrasonic power of CSM/US reactor of 16 × 400 W (total 6400 W) was operated at 20 kHz frequency. Moreover, the continuous and pulse ultrasonic modes of CSM/US reactor were compared to determine the ME purity and electricity consumption for ME production. For the CSM reactor, 12:1 M:O molar ratio and 8.5 h circulation time were recommended to realize 94.2 wt% ME purity. For the CSM/US reactor, 12:1 M:O molar ratio and 2.25 h circulation time were recommended to achieve 96.5 wt% ME purity. Under the pulsed mode operation, ME purity of 95.09 wt% was achieved, with a reduction in electricity consumption by approximately 37.6 % compared to continuous mode operation. Furthermore, the CaO/ABS catalytic static mixer was determined to be reusable for up to three cycles in both CSM and CSM/US reactors. Thus, CaO/ABS catalytic static mixers assure high purity ME production through FDM 3D printing technology with a CaO solid catalyst.

Evaluation of high-value bioproducts production by marine endophytic fungus Arthrinium sp. FAKSA 10 under solid state fermentation using agro-industrial wastes

BackgroundTo address public health challenges, there is increasing interest in bioactive metabolites from unconventional sources for targeted cancer and viral treatments with minimal side effects. Endophytic fungi are promising for these therapies. This study focused on maximizing bioactive agent yields from these fungi using a low-cost medium and optimized fermentation system. ResultsForty-three endophytic fungi isolated from Sinularia polydactyla were cultivated on wheat bran medium and evaluated for bioactive metabolites under solid-state fermentation. Strain FAKSA 10, identified as Arthrinium sp. FAKSA 10, exhibited the highest levels of pharmaceutical metabolites, including L-glutaminase, L-methioninase, L-arginase, L-asparaginase, L-tyrosinase, L-lysine α-oxidase, and ribonuclease, with a 79.12% hepatitis C virus knockdown rate. This strain produced 46 metabolites with anticancer, antioxidant, antiviral, and cytotoxic properties, including major compounds like hexadecanoic acid methyl ester; hexadecanoic acid ethyl ester; 9, 12-octadecadienoic acid (Z, Z), methyl ester; 9-octadecenoic acid (Z)-, methyl ester, and 11, 14-eicosadienoic acid, methyl ester. A cost effective strategy using 11 agro-industrial residues was applied, following by optimization of the solid-state fermentation system. This optimization increased enzyme yields and enhanced antiviral and antioxidant activities. The optimal conditions for solid-state fermentation were a 10 d incubation, 1 mm particle size, 60% initial moisture, 28°C temperature, and 2 × 107 CFU/mL inoculum size. ConclusionsThis study exploited Arthrinium sp. FAKSA 10 metabolites as natural pharmaceuticals against cancer and viral diseases, highlighting their significant antioxidant properties. Among various residues, oil cakes emerged as an effective and cost-efficient medium, capable of significantly enhancing the production of valuable bioactive metabolites.

Synthesis, Characterization, and Optimization of Antimicrobial Biolubricant Derived from Ocimum lamiifolium and Lactic Acid

Optimal extraction parameters were determined, yielding 12.4% oil at 4.5 hours, with a particle size of 1.375 mm and a solute-to-solvent ratio of 0.28 w/v. The extracted oil exhibited high yield (15% moisture, 0.92 g/mL specific gravity), a volatile lubricant component (3%), a pH of 4.2-5.91, low ash (11.5%), high saponification value (19.7 g KOH/g) and moderate acid number (8.9 mg KOH/g), iodine value of 35.3 g/L, low viscosity (0.1160 Pa.s), and high diffusion capacity (95%). Chemical analysis using UV-Vis spectrophotometry was employed to identify the constituents present in the extract, while FTIR spectra indicated the presence of alcoholic and phenolic components, suggesting interactions with lactic acid. Through GC/MS analysis, a total of 32 phytochemicals were identified, with seven significant ones: Eugenol (Phenol), Isocaryophyllene, Elemicin (benzene), Hexadecanoic acid with methyl ester, Octadecanoic acid with methyl ester, Neophytadiene and Squalene. Evaluation against E. coli, B. subtilis, S. typhimurium, and S. aureus revealed the O. lamiifolium extract and biolubricants most active against S. aureus and E. coli, suggesting potential for superior antibacterial lubricants with this plant extract and lactic acid.

Performance analysis of dual-fuel engines using acetylene and microalgae biodiesel: The role of fuel injection timing

This study evaluates the impact of varying fuel injection timing (FIT) and dual-fuel modes on the performance and emissions of a compression ignition (CI) engine under different load conditions. The biodiesel used was derived from Chlorella protothecoides microalgae through a two-step transesterification process, and its elemental composition was characterized using gas chromatography-mass spectrometry (GC-MS). Acetylene gas was introduced into the engine intake manifold at a rate of 3 L per minute (LPM), while a blend of 20 % methyl ester from Chlorella protothecoides (B20 MEOA) served as the primary injected fuel. To predict engine performance and emission characteristics, advanced machine learning models were employed and evaluated using four statistical criteria, including R-squared, mean absolute error (MAE), and mean squared error (MSE). Experimental results indicated that the optimal configuration involved a dual-fuel mode combining B20 MEOA with acetylene gas and an advanced FIT of 25° before top dead center (bTDC). Performance analysis revealed that under all load conditions, the specific fuel consumption (SFC) decreased by 7.3 %, while brake thermal efficiency (BTE) increased by 1.6 % compared to conventional diesel. Emission testing showed a 7.6 % rise in nitrogen oxide emissions, alongside significant reductions in unburned hydrocarbons (12.5 %), carbon monoxide (25.6 %), and smoke intensity (7.5 %) relative to standard diesel operation. Optimization of the engine parameters ensured that key metrics, such as brake power (BP) and brake-specific fuel consumption (BSFC), remained within acceptable limits. The random forest model outperformed other machine learning models, demonstrating superior accuracy in predicting performance and emissions across all statistical measures. This study underscores the potential of combining advanced biodiesel blends with optimized FIT strategies to improve engine efficiency and emissions control, offering a promising approach for sustainable dual-fuel engine operations.

Exacerbating orthodontic tooth movement in mice with salt-sensitive hypertension

Background/purposeOrthodontic tooth movement (OTM) is a critical aspect of dental treatment that requires the precise control of bone remodeling processes. Hypertension (HTN) can affect the effectiveness of OTM. Salt-sensitive hypertension (SSHTN) is of particular concern due to its detrimental effects on bone health, potentially altering orthodontic outcomes. This study aimed to investigate the effects of SSHTN on OTM using a mouse model. Materials and methodsMale mice were divided into a normal and an SSHTN group. The SSHTN model was generated by administering N(ω)-nitro-l-arginine methyl ester (l-NAME) followed by a high-salt diet. The OTM was performed using a nickel-titanium (Ni-Ti) closed-coil spring, and the tooth movement was measured after 12 days. Silicone imprinting was used to estimate the OTM distance. Osteoclast activity was assessed using tartrate-resistant acid phosphatase (TRAP) staining of decalcified maxillary sections. ResultsSSHTN mice exhibited significantly increased tooth movement compared to normal mice. This enhanced movement was associated with more osteoclasts in the SSHTN group than in the control group. These findings suggest that SSHTN increases OTM levels by promoting bone resorption. ConclusionSSHTN significantly affected OTM by enhancing osteoclast activity and increasing tooth movement. These results underscore the importance of considering hypertensive conditions in orthodontic treatment planning as they may require adjustments in force application to prevent potential adverse effects.

Evaluation of Microbial Phospholipase and Lipase Activity Through the Chromatographic Analysis of Crude, Degummed, and Transesterified Soybean Oil for Biodiesel Production.

The present study aimed at synthesizing fatty acid methyl esters in a combined enzymatic method by applying degumming and transesterification of soybean oil. A soluble lipase from Serratia sp. W3 and a recombinant phosphatidylcholine-preferring phospholipase C (PC-PLC) from Bacillus thuringiensis were used in a consecutive manner for phosphorus removal and conversion into methyl esters. By applying 1% of recombinant PC-PLC almost 83% of phosphorus was removed (final content of 21.01mg/kg). Moreover, a sensitive and selective high-performance liquid chromatography method coupled to tandem mass spectrometry was applied to obtain a comprehensive lipid profile for the simultaneous evaluation of phospholipids removal and diacylglycerol (DAG) increase. A significant increase for all the monitored DAG species, up to 138.42%, was observed by using the enzymatic degumming, in comparison to the crude sample, resulting in an increased oil yield. Serratia sp. W3 lipase was identified as a suitable biocatalyst for biodiesel production, converting efficiently the acylglycerols. The results regarding the physical-chemical characteristics show that the cetane level, density and pour point of the obtained biodiesel are close to current regulation requirements. These findings highlight the potential of a two-step process implementation, based on the combination of lipase and phospholipase, as a suitable alternative for biodiesel production.

Impaired microvascular insulin-dependent dilation in women with a history of gestational diabetes.

Women with a history of gestational diabetes mellitus (GDM) have a significantly greater lifetime risk of developing cardiovascular disease and type 2 diabetes compared with women who had an uncomplicated pregnancy (HC). Microvascular endothelial dysfunction, mediated via reduced nitric oxide (NO)-dependent dilation secondary to increases in oxidative stress, persists after pregnancy complicated by GDM. We examined whether this microvascular dysfunction reduces insulin-mediated vascular responses in women with a history of GDM. We assessed in vivo microvascular endothelium-dependent vasodilator function by measuring cutaneous vascular conductance responses to graded infusions of acetylcholine (10-10-10-1 M) and insulin (10-8-10-4 M) in control sites and sites treated with 15 mM l-NAME [NG-nitro-l-arginine methyl ester; NO-synthase (NOS) inhibitor] or 5 mM l-ascorbate. We also measured protein expression of total endothelial NOS (eNOS), insulin-mediated eNOS phosphorylation, and endothelial nitrotyrosine in isolated endothelial cells from GDM and HC. Women with a history of GDM had reduced acetylcholine (P < 0.001)- and insulin (P < 0.001)-mediated dilation, and the NO-dependent responses to both acetylcholine (P = 0.006) and insulin (P = 0.006) were reduced in GDM compared with HC. Insulin stimulation increased phosphorylated eNOS content in HC (P = 0.009) but had no effect in GDM (P = 0.306). Ascorbate treatment increased acetylcholine (P < 0.001)- and insulin (P < 0.001)-mediated dilation in GDM, and endothelial cell nitrotyrosine expression was higher in GDM compared with HC (P = 0.014). Women with a history of GDM have attenuated microvascular vasodilation responses to insulin, and this attenuation is mediated, in part, by reduced NO-dependent mechanisms. Our findings further implicate increased endothelial oxidative stress in this microvascular insulin resistance.NEW & NOTEWORTHY Women who have gestational diabetes during pregnancy are at a greater risk for cardiovascular disease and type 2 diabetes in the decade following pregnancy. The mechanisms mediating this increased risk are unclear. Herein, we demonstrate that insulin-dependent microvascular responses are reduced in women who had gestational diabetes, despite the remission of glucose intolerance. This reduced microvascular sensitivity to insulin may contribute to increased cardiovascular disease and type 2 diabetes risk in these women.

Time of day affects MrgD-dependent modulation of cardiomyocyte contractility.

The renin-angiotensin system (RAS) is composed of a series of peptides, receptors, and enzymes that play a pivotal role in maintaining cardiovascular homeostasis. Among the most important players in this system are the angiotensin-II and angiotensin-(1-7) peptides. Our group has recently demonstrated that alamandine (ALA), a peptide with structural and functional similarities to angiotensin-(1-7), interacts with cardiomyocytes, enhancing contractility via the Mas-related G protein-coupled receptor member D (MrgD). It is currently unknown whether this modulation varies along the distinct phases of the day. To address this issue, we assessed the ALA-induced contractility response of cardiomyocytes from mice at four Zeitgeber times (ZTs). At ZT2 (light phase), ALA enhanced cardiomyocyte shortening in an MrgD receptor-dependent manner, which was associated with nitric oxide (NO) production. At ZT14 (dark phase), ALA induced a negative modulation on the cardiomyocyte contraction. β-Alanine, an MrgD agonist, reproduced the time-of-day effects of ALA on myocyte shortening. NG-nitro-l-arginine methyl ester, an NO synthase inhibitor, blocked the increase in fractional shortening induced by ALA at ZT2. No effect of ALA on myocyte shortening was observed at ZT8 and ZT20. Our results show that ALA/MrgD signaling in cardiomyocytes is subject to temporal modulation. This finding has significant implications for pharmacological approaches that combine chronotherapy for cardiac conditions triggered by disruption of circadian rhythms and hormonal signaling.NEW & NOTEWORTHY Alamandine, a member of the renin-angiotensin system, serves critical roles in cardioprotection, including the modulation of cardiomyocyte contractility. Whether this effect varies along the day is unknown. Our results provide evidence that alamandine via receptor MrgD exerts opposing actions on cardiomyocyte shortening, enhancing, or reducing contraction depending on the time of day. These findings may have significant implications for the development and effectiveness of future cardiac therapies.

Elucidating the hysteresis effect in printed flexible perovskite solar cells with SnO2 quantum dot- and PCBM-based electron transport layers

Recently, flexible perovskite solar cells (FPSCs) fabricated using solution-processed printing techniques have garnered significant attention. However, challenges remain in achieving cost-effective, scalable manufacturing under ambient conditions and ensuring stable, efficient devices. This study focuses on fabricating printed FPSCs using the slot-die coating technique and examines the impact of SnO2 quantum dot (QD) and (6,6)-Phenyl C61 butyric acid methyl ester (PCBM) based electron transport layers (ETLs) on device performance and hysteresis. Experimentally results show that SnO2 QD-based devices exhibited favorable photovoltaic properties but significant hysteresis compared to PCBM-based devices. Numerical simulations have shown that the hysteresis effect in devices is influenced not only by the higher concentration of mobile ions in the perovskite layer of PCBM-based devices compared to SnO2 QD-based devices, but also by the more effective redistribution of these ions during forward and reverse J-V scans. The results provide insights into the behavior of printed FPSCs with different ETLs, contributing to the development of high-performance, hysteresis-free printed FPSCs.

Preparation of two new chiral metal-organic frameworks for lipase immobilization and their use as biocatalysis in the enantioselective hydrolysis of racemic naproxen methyl ester

Considering the selective pharmacological activity of chiral drugs, it is important to develop new chiral materials to synthesize them. In this work, two new chiral MOFs (UiO-66@Np and UiO-66@Ib) were prepared by the covalent attachment of the chiral compounds (S-naproxen and S-ibuprofen) to the amine-functionalized Zr-MOF (UiO-66-NH2). Then, Candida rugosa lipase (CRL) was immobilized on these chiral MOFs to fabricate two new biocomposites (UiO-66@Np@CRL and UiO-66@Ib@CRL) as effective biocatalysts, which enable significant enhancement in the catalytic activity and enantioselectivity of lipase. The FTIR, SEM, EDX, TGA, and PXRD analyses were carried out to confirm the formation of the biocomposites. The catalytic performances of the biocomposites (UiO-66@Np@CRL and UiO-66@Ib@CRL) were evaluated in the typical hydrolysis of p-nitro-phenyl palmitate (p-NPP) and the catalytic enantioselective hydrolysis of (R,S)-naproxen methyl ester. Under optimal conditions, UiO-66@Np@CRL showed a higher enantiomeric excess of the substrate (ees) value and a 98 % and 50 % conversion rate, respectively, than that of UiO-66@Ib@CRL. Besides, an excellent enantioselectivity (E) value of 458 was obtained in the presence of the biocomposite (UiO-66@Np@CRL). In addition, it was observed that the catalytic activity, conversion rate and ees value of this composite (UiO-66@Np@CRL) remained almost unchanged in reuse after 6 months. The results showed that in enantioselective reactions, the highest conversion and enantioselectivity could be achieved when the chiral compound bound to the MOF and the model compound used are the same.