Free Synthesis Research Articles

SENTINEL-2 SURFACE REFLECTANCE PRODUCTS GENERATED BY CNES AND DLR: METHODS, VALIDATION AND APPLICATIONS

Abstract. To allow for a robust and automatic exploitation of Sentinel-2 data, Analysis Ready Data (ARD) products are requested by most users. The processors of ARD products take care of the common burdens necessary for most applications, that include precise orthorectification, cloud detection and atmospheric correction steps, as well as the generation of periodic syntheses of cloud free surface reflectances. The French Theia land data center, and the German Earth Observation Center (EOC) started delivering Sentinel-2 surface reflectance products to users in 2016 in France and 2019 in Germany respectively. Both centers produce and distribute these data sets in near real time, over large regions requested by French users such as Western Europe, Maghreb, Sahel, Madagascar… Theia’s and EOC products include an instantaneous surface reflectance product (Level-2A), and a monthly cloud free synthesis of surface reflectance (Level-3A). This article shortly describes the methods used to generate the Level-2A products with the MAJA processor, and the Level-3A products with theWASP processor. The MAJA processor is based on multi-temporal methods, that use the slow variation of surface reflectance to detect clouds and estimate aerosol depth, while WASP, thanks to the quality of MAJA cloud mask, calculates a weighted average of all the cloud free observations over 45 days, every month. The article also provides validation results for Level-2A and Level-3A products, resulting from comparison with in-situ data and with other methods. A last section gives first insights from the monitoring of user uptake of the distributed products.

Cell free protein synthesis versus yeast expression – A comparison using insulin as a model protein

Expression of recombinant proteins traditionally require a cellular system to transcribe and translate foreign DNA to a desired protein. The process requires special knowledge of the specific cellular metabolism in use and is often time consuming and labour intensive. A cell free expression system provides an opportunity to express recombinant proteins without consideration of the living cell. Instead, a cell free system relies on either a cellular lysate or recombinant proteins to carry out protein synthesis, increasing overall production speed and ease of handling. The one-pot cell free setup is commonly known as an in vitro transcription/translation reaction (IVTT).Here we focused on a PURE (Protein synthesis Using Recombinant Elements) IVTT system based on recombinant proteins from Escherichia coli. We evaluated the cell free system's ability to express functional insulin analogues compared to Saccharomyces cerevisiae, a well-established system for large scale production of recombinant human insulin and insulin analogues.Significantly, it was found that correct insulin expression and folding was governed by the inherent properties of the primary amino acids sequence of insulin, whereas the eukaryotic features of the expression system apparently play a minor role. The IVTT system successfully produced insulin analogues identical in structure and with similar insulin receptor affinity to those produced by yeast. In conclusion we demonstrate that the PURE IVTT system is highly suited for expressing soluble molecules with higher order features and multiple disulphide bridges.

A Greener Synthesis of Fe-N-C Catalysts for the Oxygen Reduction Reaction

The world is faced with an ever-increasing energy demand that, under the aspect of global warming, must be covered by renewable sources such as wind- and solar energy. However, the main challenge linked to these sources is to provide a continuous energy supply, demanding highly efficient energy storage and conversion devices.One promising conversion technology are fuel cells. [1] These usually rely on expensive and rare platinum group metal (PGM) catalysts for the sluggish oxygen reduction reaction (ORR). In order to serve the human energy demand, cheap and scalable fuel cell systems are required. The class of M-N-C (M = Fe, Mn, Co) type catalysts shows particularly good catalytic behaviour comparable to PGM based catalysts. However, promising catalysts are usually synthesised from toxic materials with solvent and energy intensive methods. [2]Here, we present a synthetic approach towards Fe-N-C type catalysts, that uses only non-hazardous chemicals, produces no wastewater and is more energy efficient than classical approaches. We used iron hydroxide as iron source for its lower environmental impact as compared to ferric chloride. Cyanoguanidine (non-toxic) was chosen over cyanamide (toxic) as a pore forming agent and nitrogen source. Tryptophan was used over PANI and the like for its availability from natural sources with no need for toxic precursors. Instead of classical wet chemical approaches we used a solvent free mechanochemical synthesis. And by using vulcan carbon as electron conducting scaffold, we were able to carbonize at 750 °C, increasing the overall energy efficiency. The catalytic activity towards the ORR of the obtained catalysts was determined by rotating disc electrode measurements in acidic and basic media. With a 100 mV lower onset potential, their performance in an alkaline environment is good but not quite comparable to Pt based catalysts.Future studies will focus on the correlation of nitrogen content as well as porosity of the catalysts with their electrocatalytical behaviour.[1] I. Staffell, D. Scamman, A. Velazquez Abad, P. Balcombe, P. E. Dodds, P. Ekins, N. Shah, K. R. Ward, Energy Environ. Sci. 2019, 12, 463–491.[2] H. T. Chung, D. A. Cullen, D. Higgins, B. T. Sneed, E. F. Holby, K. L. More, P. Zelenay, Science 2017, 357, 479-484. Figure 1

Lipase catalyzed solvent free synthesis of monoacylglycerols in various reaction systems and coupling reaction with pervaporation for in situ water removal

This work reports a practical comparison of simple reaction systems for enzymatic production of monoacylglycerols (MAG) from lauric- and caprylic acid. Two approaches namely shake flasks and packed bed reactor (from 60 g to 3 kg scale) were compared as well as water removal strategies such as adsorption on molecular sieves, N2 stripping and hydrophilic pervaporation, were studied. In all the reactor systems high fatty acid conversion (>90%) was achieved in solvent free conditions. The product profile obtained showed 35 wt% - 50 wt% MAG in various systems and was related to final fatty acid conversion as well as reaction conditions and set-ups. The selectivity of products in the tested systems, ranged from 55 to 70 wt% mono-, 30–35 wt% di- and 1–10 wt% triacylglycerols. Packed bed reactor enabling enzyme reuse, was coupled with pervaporation, demonstrating practical applicability of zeolite based membranes for in situ water removal.

Ethyl‐2‐Cyano‐2‐(2‐Nitrophenylsulfonyloximino)Acetate (ortho‐NosylOXY) Mediated One‐Pot Racemization Free Synthesis of Ureas, Carbamates, and Thiocarbamates via Curtius Rearrangement

AbstractDirect conversion of carboxylic acids to ureas, carbamates, and thiocarbamates in a single pot via Curtius rearrangement is accomplished. One recently established coupling reagent, Ethyl‐2‐cyano‐2‐(2‐nitrophenylsulfonyloximino)acetate (ortho‐NosylOXY, I), is successfully used for the racemization free synthesis of ureas, di‐peptidyl ureas, and carbamates with moderate to good yield (82–69%). This single‐pot hassle‐free procedure works with a diverse range of N‐protecting groups Fmoc, Boc, and Cbz. Various amine, including aromatic, methyl esters of amino acids, t‐butylamine, alcohols, and thiols, are used as nucleophiles. A detailed NMR‐based mechanism study is incorporated here. Racemization suppression, easy removal of by‐products, and less waste generation make this methodology useful.

In Vitro Protein Synthesis in Semipermeable Artificial Cells.

A novel cell free protein synthesis (CFPS) system utilizing layer-by-layer (LbL) polymer assembly was developed to reduce the operational cost of conventional CFPS. This yielded an encapsulated cell system, dubbed "eCells", that successfully performs in vitro CFPS and allows cost-effective incorporation of noncanonical amino acids into proteins. The use of eCells in CFPS circumvents the need for traditional cell lysate preparation and purification of amino acyl-tRNA synthetases (aaRS) while still retaining the small scale of an in vitro reaction. eCells were found to be 55% as productive as standard dialysis CFPS at 13% of the cost. The reaction was shown to be scalable over a large range of reaction volumes, and the crowding environment in eCells confers a stabilizing effect on marginally stable proteins, such as the pyrrolysl tRNA synthetase (PylRS), providing a means for their application in in vitro protein expression. Photocaged-cysteine (PCC) and Nε-(tert-butoxycarbonyl)-l-lysine (Boc-lysine) were incorporated into Peptidyl-prolyl cis-trans isomerase B (PpiB) using small amounts of ncAA with an adequate yield of protein. Fluorescent activated cell sorting (FACS) was used to demonstrate the partition of the lysate within the eCells in contrast to standard one pot cell lysate-based methods.

BCl3 Catalyzed, Solvent Free Protocol for the Synthesis of Dihydropyrano[ 3,2-b] Chromenediones

: Solvent free synthesis of dihydropyrano[3,2-b]chromenediones was formulated via multicomponent reactions of kojic acid, dimedone and several substituted aromatic aldehydes catalyzed with BCl3. Reactions progressed efficiently and the corresponding heterocyclic products were obtained in good to high yields within short period. The developed protocol is one of the better and efficient alternative methods for the synthesis of dihydropyrano[3,2-b]chromenediones. The simple reaction procedure, easy separation of products, radially available catalyst are certain benefits of this reported protocol.

Ecofriendly Solvent Free Synthesis, Characterization and Bioactivity Study of Transition Metal Complexes of a New Schiff Base Derived From 2-Amino-5, 6-Dimethyl Benzimidazole and Acenaphthenequinone

Ecofriendly Solvent Free Synthesis, Characterization and Bioactivity Study of Transition Metal Complexes of a New Schiff Base Derived From 2-Amino-5, 6-Dimethyl Benzimidazole and Acenaphthenequinone

Design of a 1 MWth Pilot Plant for Chemical Looping Gasification of Biogenic Residues

Chemical looping gasification (CLG) is a promising process for the thermochemical solid to liquid conversion route using lattice oxygen, provided by a solid oxygen carrier material, to produce a nitrogen free synthesis gas. Recent advances in lab-scale experiments show that CLG with biomass has the possibility to produce a carbon neutral synthesis gas. However, all experiments have been conducted in externally heated units, not enabling autothermal operation. In this study, the modification of an existing pilot plant for demonstrating autothermal operation of CLG is described. Energy and mass balances are calculated using a validated chemical looping combustion process model extended for biomass gasification. Based on six operational cases, adaptations of the pilot plant are designed and changes discussed. A reactor configuration using two circulating fluidized bed reactors with internal solid circulation in the air reactor is proposed and a suitable operating strategy devised. The resulting experimental unit enables a reasonable range of operational parameters within restrictions imposed from autothermal operation.

Solvent Free Synthesis of some Metal Complexes of Novel Ligand Derived from 2-Amino-5, 6-Dimethyl Benzimidazole with 2-Bromo Isophthalaldehyde and Characterization, Biological Activity of Same

Solvent Free Synthesis of some Metal Complexes of Novel Ligand Derived from 2-Amino-5, 6-Dimethyl Benzimidazole with 2-Bromo Isophthalaldehyde and Characterization, Biological Activity of Same

144 Barrier disruption and inflammatory skin models to evaluate cosmetic formulations on lipid metabolism

Primary function of the skin is to protect the body from environment and excessive water loss. Skin is characterized by active lipid metabolism and lipids play crucial roles both in terms of structural integrity and functionality. Lipid metabolism can be modified by skin barrier alteration and inflammation leading to modification of ceramides and free fatty acids ratio inducing barrier dysfunction. Aim of this study was to investigate, on 3-dimentional skin model, barrier alteration effect and inflammation on lipid metabolism (enzymes expression and lipid levels) and to evaluate different formulations in order to balance negative impact of the stress. Ex vivo human skin model exposed to SDS and reconstructed epidermis model with TNFα stress were used. Enzyme expression (ALOX12B and EVOL1) was performed by immunofluorescence staining with confocal microscopy. Ceramides, free fatty acids and cholesterol synthesis were analysed using chromatographic method. Mass spectrometry imaging (MSI) allowed to follow skin penetration of lipophilic ingredients of formulations. SDS barrier alteration decreased significantly ALOX12B expression and increased EVOL1 expression. Epidermal lipids synthesis was also modified after inflammatory stress, in particular, ceramides ratio leading to impairment of the barrier function. Same trends were described in vivo for pathologies like ichthyosis, atopic dermatitis and psoriasis. The different lipidic constituents of formulations penetrated and were localized into the SC and viable epidermis by MSI. Rhealba® oat plantlets extract formulation permitted to restore lipid metabolic disorders and balance ceramides ratio. Skin models demonstrated the impact of barrier alteration and inflammation on lipid metabolism. These skin models can be used to evaluate cosmetic formulations on lipid metabolism to preserve barrier function with can be specifically altered in different inflammatory pathologies.

Ultrasound promoted synthesis of N-(substituted phenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides as cytotoxic and antioxidant agents

New N-(substituted phenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamides (5a-l) was synthesized in two steps using environmentally friendly ultrasound irradiation. The first step involved solvent free synthesis of 7‑hydroxy-4-methyl-2H-chromen-2-one (3) by using catalytic amount (10% mol) of FeCl3. The second step involved condensation of intermediate 3 and hydrazine carboxamide HCl analogues (4a-l) under ultrasonic influence in the water-ethanol (2:1) solvent system to obtain the title compounds (5a-l) in good yield. The structure of prepared compounds (5a-l) was confirmed by spectroscopic study. The synthetic strategy described here has many advantages, including a simple procedure and high conversion with quick reaction times. The cytotoxicity was tested on 60 NCI cancer cell lines at 10 µM and N-(4-chlorophenyl)-2-(7‑hydroxy-4-methyl-2H-chromen-2-ylidene)hydrazine-1-carboxamide (5b) showed promising activity with maximum sensitivity against CCRF-CEM, UO-31, RPMI-8226, NCI-H522, and HL-60(TB) with growth percent (GP) of 17.50, 79.67, 80.59, 82.35, and 83.70 respectively. In a DPPH free radical scavenging assay, the compounds 5b and 5d showed promising antioxidant activity with IC50 values of 16.32±1.29 and 14.28±1.82 M, respectively. The binding affinity of the target ligands (5a-l) against the active site of FGFR was also investigated using molecular docking. Within the active site of FGFR4, the ligand 5b interacted with four H-bonds with Asp630 (carbonyl function), Glu520 (with amide NH and ArNH), and Ile609 (phenol function), while an imine “N” showed two salt bridges with Asp630 and Glu520.

Impact of curcumin on fatty acid metabolism.

Free fatty acids (FFAs) and fatty acid synthesis (FAS) activity have significantly contributed to disease states such as insulin resistance, obesity, type 2 diabetes, myocardial infarction, blood pressure, and several types of cancer. Currently, several treatment options are available for patients with these conditions. Due to safety concerns, adverse effects, limited efficacy, and low tolerability associated with many medications, the identification of novel agents with less toxicity and a more favorable outcome is warranted. Curcumin is a phenolic compound derived from the turmeric plant with various biological activities, including anticarcinogenic, antioxidant, antiinflammatory, and hypolipidemic properties. PubMed, Scopus, and Web of Science were searched up to February 2020 for studies that demonstrated the efficacy and mechanisms of curcumin action on FFAs, FAS, and β-oxidation activity, as well as the desaturation system. Most of the evidence is in-vivo and in-vitro studies that demonstrate that curcumin possesses regulatory properties on FFAs levels through its effects on FAS and β-oxidation activity as well as desaturation system, which could improve insulin resistance, obesity, and other FFAs-related disorders. The present study provides a review of the existing in-vitro, in-vivo, and clinical evidence on the effect of curcumin on FFAs and FAS activity, β-oxidation, and desaturation system.

Co-Solvent Free Electrochemical Synthesis of Biodiesel Using Graphite Electrode and Waste Concrete Heterogeneous Catalyst: Optimization of Biodiesel Yield

This study optimized a co-solvent free electrochemical method for biodiesel synthesis using graphite electrode and waste concrete heterogeneous catalyst. Various parameters were evaluated, including: applied voltage (9.6, 14.4, 19.2 V), catalyst particle size uniformity (unfiltered and filtered with 150 mesh), and reaction time (15, 30, 120, 240 min). The results obtained 100% FAME content and 78.51% of biodiesel yield that were achieved at 14.4 V within 30 min using filtered catalyst and cooking oil feedstock. However, a slight decline was observed with the use of waste cooking oil. This optimized method offers a reliable and simple condition for mass biodiesel production. 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).

X-ray Free Electron Laser-Induced Synthesis of ε-Iron Nitride at High Pressures.

The ultrafast synthesis of ε-Fe3N1+x in a diamond-anvil cell (DAC) from Fe and N2 under pressure was observed using serial exposures of an X-ray free electron laser (XFEL). When the sample at 5 GPa was irradiated by a pulse train separated by 443 ns, the estimated sample temperature at the delay time was above 1400 K, confirmed by in situ transformation of α- to γ-iron. Ultimately, the Fe and N2 reacted uniformly throughout the beam path to form Fe3N1.33, as deduced from its established equation of state (EOS). We thus demonstrate that the activation energy provided by intense X-ray exposures in an XFEL can be coupled with the source time structure to enable exploration of the time-dependence of reactions under high-pressure conditions.

Multivariate statistical data analysis of cell‐free protein synthesis toward monitoring and control

AbstractThe optimization and control of cell free protein synthesis (CFPS) presents an ongoing challenge due to the complex synergies and nonlinearities that cannot be fully explained in first principle models. This article explores the use of multivariate statistical tools for analyzing data sets collected from the CFPS of Cereulide monoclonal antibodies. During the collection of these data sets, several of the process parameters were modified to investigate their effect on the end‐point product (yield). Through the application of principal component analysis and partial least squares (PLS), important correlations in the process could be identified. For example, yield had a positive correlation with pH and NH3 and a negative correlation with CO2 and dissolved oxygen. It was also found that PLS was able to provide a long‐term prediction of product yield. The presented work illustrates that multivariate statistical techniques provide important insights that can help support the operation and control of CFPS processes.

Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest

In this work we studied the reactivity of the Trifluoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifluoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1 h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383 K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifluoroacetate of the hydroxylamine with a modified nitric acid hydrogenation reactions was verified, too. Reuse of solvent and trifluoroacetic acid is easily achieved by distillation.Graphical abstractSalt free one-pot caprolactam and amides process catalyzed by CF3COOH, in the presence of NH2OH TFA as the oximation agent.

Phase‐Controlled Synthesis of Zeolites from Sodium Aluminosilicate under OSDA/Solvent‐Free Conditions

AbstractOSDA/solvent‐free synthesis of zeolites is suitable for practical commercialization due to low environmental damage and low cost. However, only a few types of zeolites have been successfully synthesized by this method. In this study, ANA, CAN, GIS, SOD, FAU and LTA type zeolites were synthesized by the OSDA/solvent‐free synthesis method by changing the Si/Al ratio and crystallization temperature in detail. At higher Si/Al ratios, FAU, GIS and ANA type zeolites were obtained with an increase of crystallization temperature. Meanwhile, at lower Si/Al ratios, LTA, SOD and CAN type zeolites were obtained with an increase of crystallization temperature. It was found that zeolites with high T atom density were synthesized with an increase of the crystallization temperature; zeolite with a high T atomic density is more stable. This work reveals the correlation between the Si / Al ratio and the crystallization temperature in OSDA/solvent‐free synthesis of zeolites, which provides a clear guideline for the OSDA/solvent‐free synthesis of zeolites.

Modal Analysis of Complex Structures via a Sub-Structuring Approach

In this paper, the problems arising from determining the modal properties of large and complex structures are investigated. For this purpose, the free interface component mode synthesis method has been used. In the following, Singular-Value Decomposition (SVD) is applied as a powerful mathematical tool to determine the appropriate coordinates to participate in the coupling process. Also, the effective error resources including modal shear error and the continuous systems overlapping error and their solution are introduced. Initially, a discrete system has been employed to investigate the free interface component mode synthesis method. Eventually, the studied main samples in this research are beam, plate and cylindrical shell. It is worth noting that the application of this method on the cylindrical shell has not been observed in previous researches.

Surfactant free synthesis and characterization of α-MoO3 nanoplates: A feasibility study to remove methylene blue from aqueous medium

Orthorhombic a-MoO3 nanoplates have been synthesized by surfactant free chemical method. The prepared samples were analysed by various characterization techniques viz. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive analysis of X-ray (EDAX), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and Diffused reflectance spectroscopy (DRS). The XRD profile revealed the orthorhombic phase of the prepared material and obtained structural parameter confirms the formation of α-MoO3. EDAX depicts the prepared material’s compositional proportion and has no traces of the foreign elements as well. The topographic images of SEM indicate formation of nanoplate shaped MoO3 having a thickness in range of 200 to 300 nm. FTIR and Raman, on the basis of vibrational behaviour of chemical bonds present in the material, confirm the formation of orthorhombic MoO3. DRS study shows the band gap is about 2.95 eV. Further, the study of adsorption of methylene blue (MB) by synthesized MoO3 shows its potential application in the waste water treatment.