Chain Length Research Articles

The texture of potato mashes is impacted by blanching induced changes in their extracellular starch fractions

The texture of potato mash significantly influences consumer satisfaction. We here investigated the impact of blanching and different methods thereof on the texture and extractable extracellular fractions (EEFs) of potato mash when extracted with water or with dimethyl sulfoxide (DMSO) to seek determining factors of potato mash texture. Mashes prepared from potatoes blanched in 2.04 mM CaCl2 (CaB-M) exhibited hardness (24.9 N) and stickiness (1.0 N·s) readings intermediate to those from potatoes that were not blanched (NB-M, 19.2 N and 1.2 N·s), or blanched in deionized water (WaB-M, 30.5 N and 0.6 N·s), which aligned with their levels of intact cells. Starch was the main constituent (57.2 % – 64.4 %, w/w) in all EEFs and more starch was present in (1) NB-M and (2) the DMSO extracts. The chain length distributions of DMSO-extracted extracellular starch (DEES) revealed that the amylopectin content increased in the order WaB-M (46.3 %), CaB-M (55.1 %), and NB-M (76.6 %), which was attributed to more intracellular amylopectin being released to the extracellular phase of mashes. The relative contents of shorter chain amylose (degree of polymerization 110–1000) and the DEES yield were significantly correlated to the hardness while the yield of DEEFs was positively correlated with the stickiness.

Magnetic and electronic properties of 1D hybrid nanoobjects composed of alternating polycyclic hydrocarbon regions and double carbon chains

It has been proposed recently that 1D hybrid nanoobjects consisting of alternating double carbon chains and polycyclic carbon regions can be obtained from graphene nanoribbons of alternating width by electron irradiation. Here, based on density functional theory calculations, we show that magnetic and electronic properties of such nanoobjects can be changed dramatically by modifying the chain length and edge structure of polycyclic regions and this opens wide possibilities for spintronic applications. Nanoobjects composed of polycyclic regions with dangling bonds and even chains are found to behave as magnetic semiconductors that can generate spin-polarized currents. Band gaps of nanoobjects with odd chains change considerably upon switching between magnetic states making them promising for magnetic tunnel junctions. We also demonstrate that use of a hybrid exchange–correlation functional is important to properly describe stability of magnetic states, band gaps and synergistic effects of nanoobject components leading, for example, to magnetism in even chains.

Mechanism underlying V-type structure formation in maize starch through glycerol–ethanol thermal substitution method

V-type starches have been widely used in food science, agriculture, and biomedical science, but their mechanism of formation in nonaqueous solvents remains unclear. This study performed glycerol–ethanol thermal substitution to prepare V-type starch at atmospheric pressure. Scanning electron microscopy and confocal laser scanning microscopy revealed that breakage of starch particles began in the hilum region and rapidly spread to the periphery with the temperature increased from 100 °C to 130 °C. The Maltese crosses of the starch disappeared and starch particles had the form of doughnut-shaped rings when the glycerol temperature was 140 °C. Glycerol temperature was not found to significantly affect the chain length of amylopectin, meaning that glycerol molecules may stabilize the conformation of amylose through hydrogen bonding, promoting the amylose to form a V-type spiral structure. Additionally, A-type crystallinity and double helix structure proportion of the samples significantly decreased from 30.81 % and 42.21 % to 5.70 % and 16.47 % as the temperature of glycerol was increased to 140 °C, whereas the V-type crystallinity and single helix structure proportion of the samples remarkably increased from 13.26 % and 1.05 % to 37.97 % and 25.09 %, respectively. This study provided a facile and versatile approach to effectively regulate the formation of V-type starch.

Multiscale assessment of the effect of a stearic-palmitic sucrose ester on the crystallization of anhydrous milk fat

Anhydrous milk fat (AMF) is a flavourful, but particularly complex fat containing a wide variety of fatty acids (FAs) and triglycerides (TGs), resulting in an extended melting range of −40 °C to 40 °C. The functionality of this fat can be steered by the addition of sucrose esters (SEs). In this study, the crystallization behavior of AMF in the presence of a stearic-palmitic SE was assessed. Samples were cooled at 1 °C/min (slow cooling) or 20 °C/min (fast cooling) to 0, 20 or 25 °C and kept isothermal for one hour. At each of these temperatures, milk fat was found to crystallize via different polymorphic pathways and chain length structures, as studied by wide- and small-angle X-ray scattering. The addition of the SE (0.5 wt%) accelerated nucleation and allowed crystallization to start at higher temperatures. Polymorphic transitions were accelerated, but not changed. For fast-cooled samples, ultra-small-angle X-ray scattering provided insights into the mesoscale behavior of the crystal nanoplatelets (CNPs). It was observed that CNPs formed at 20 °C were smaller than those at 25 °C. The addition of the SE did not change the size nor the shape of CNPs. Polarized light microscopy (PLM) and cryo-scanning electron microscopy (cryo-SEM) gave insight into the microstructure of the networks. Addition of the SE resulted in more fine and dense fat crystal networks at 0 and 20 °C. At 25 °C, large separate floc structures were encountered, with and without the addition of the SE.

Molecular engineering of tethered bilayer lipid membranes for impedimetric detection of pore-forming toxins

Tethered bilayer lipid membranes (tBLMs) with two different molecular architectures were investigated in the context of their utility for biosensing of pore-forming toxins (PFTs). The different architectures were achieved by using two back-filler molecules of different chain length to act as surface diluents for the molecular anchors [20-tetradecyloxy-3,6,9,12,15,18,22-heptaoxahexatricontane-1-thiol (WC14)] that ensure immobilization of the phospholipid bilayers on a solid conductive (metal, such as gold) support. The back-filler molecules were β-mercaptoethanol (BME) and HS(CH2)3(CH2CH2O)5H thiol (C3EO5H). In the case of BME, the submembrane space separating solid surface from attached bilayer (typically 1-2 nm thick) is populated with the ice-like, presumably low entropy and low dielectric constant water, however, the water fraction in the submembrane is high. Much bulkier C3EO5H back-filler renders less space for water in the submembrane, however, it is populated with more mobile water molecules resulting in higher dielectric constant. These two opposing effects result in similar submembrane specific conductances, i.e., the specific electrochemical impedance spectral (EIS) characteristics of the tBLMs and their variation, upon exposure to and reorganization with, the pore-forming toxin (PFT), alpha-hemolysin, occur in the same frequency range for both back-fillers. Significantly, the sensitivity of the C3EO5H-containing tBLMs to PFT is approximately 7–8 times higher than that of the BME-containing surface constructs. At least two physical phenomena contribute to this difference. The bulkier C3EO5H back-fillers facilitate the formation of nanoclusters of the molecular anchors, WC14, with cluster sizes ranging from 20–120 nm. These highly anchor-clustered, “patchy” tBLMs, consequently exhibit other domains devoid, or nearly so, of anchors, resulting in lowering the tBLM global 2-D viscosity by a factor of 3. Thus, a major conclusion of this study is that lower tBLM 2D fluidity increases the sensitivity of tBLMs to PFTs.

Impacts of hydrophobic chain length on foam stability and CO2 geo-sequestration capacity of sugar-based nonionic surfactants: Molecular dynamics simulation and laboratory experiments

Impacts of hydrophobic chain length on foam stability and CO2 geo-sequestration capacity of sugar-based nonionic surfactants: Molecular dynamics simulation and laboratory experiments

Study on Several Novel Crystalline Complexes of Sorafenib with Dicarboxylic Acid: Nature Identification and Solubilization Mechanism

The development of solid-state forms of drugs is an effective approach to increase solubility. This study developed three crystalline complexes of sorafenib (SF) with oxalic acid (OA) and malonic acid (MA) using a solvent method, named SF+·OA-·THF, SF+·OA-, and SF-MA. The formation of these complexes was influenced by the crystalline method, solvent polarity, and the carbon chain length of the dicarboxylic acids. Single-crystal X-ray diffraction revealed proton transfer in SF+·OA-·THF, classifying it as a channel-type salt solvate and conformational polymorph due to hydrogen bond formation. 13C solid-state nuclear magnetic resonance and X-ray photoelectron spectroscopy confirmed proton transfer in SF+·OA-·THF and SF+·OA-, but not in SF-MA, indicating that SF+·OA- is a salt while SF-MA is a co-crystal. Fourier Transform Infrared Spectroscopy further supported these findings. Compared with Form Ⅰ, SF+·OA-, SF+·OA-·THF, and SF-MA increased the apparent solubility of SF by 8.3, 7.9, and 6.4 times in pH 1.2 HCl buffer, and by 4.0, 3.1, and 4.5 times in pH 6.8 PBS buffer, respectively. All crystalline complexes exhibited a “spring and parachute” phenomenon due to the solubility difference between the drug and the dicarboxylic acids. Notably, the intermolecular forces between SF and THF in SF+·OA-·THF prolonged the “spring and parachute” process. Additionally, these crystalline complexes demonstrated good stability. This study provides valuable insights into the development and identification of crystalline complexes and their dissolution mechanisms.

Effect of gas type on properties of anionic surfactant foam system

The foam drainage technique is considered to be a promising measure for solving the problem of liquid accumulation in natural gas wells and gathering pipelines. However, differences in gases can greatly affect the performance of surfactant foam, thus limiting the application of this technology. To elucidate the mechanism of natural gas components influencing foam properties, the interfacial properties of hydrocarbon gas-surfactant-water system were analyzed thermodynamically and kinetically by combining molecular dynamics simulations and foaming experiments. The results show that with the increasing alkane chain length, the foaming volume and half-life of the foam are gradually rising, while the gas–liquid interfacial tension is decreasing, which is consistent with the results of molecular dynamics simulations. Compared with air, hydrocarbon gases are more beneficial for foam generation and stabilization. The interfacial adsorption of alkane molecules and the interaction between alkanes and surfactants are the main factors affecting the interfacial tension and film stability of different systems.

Synthesis, characterization, and application of films made from highly substituted N-perfluoroacylated chitosan

Highly substituted perfluoroacylated chitosan can alter the physicochemical properties of chitosan; however, the currently synthesized perfluoroacylated chitosan has a low degree of substitution. In this study, we present a simple method for the homogeneous preparation of highly substituted N-perfluoroacylated chitosan, conducted at room temperature without requiring strict anhydrous or oxygen-free conditions. Various perfluorocarbon chains were successfully attached to chitosan through a reaction between perfluorinated acid esters and amines, catalyzed by DBU. The synthesized N-perfluoroacylated chitosan, with high degree of substitution, demonstrated excellent solubility in common organic solvents. Comprehensive characterization was performed using elemental analysis, nuclear magnetic resonance (including two-dimensional NMR), gel permeation chromatography, infrared spectroscopy, X-ray diffraction, and thermal analysis. The resulting films exhibited high water contact angles. Notably, as the fluorocarbon chain length increased, tensile strength gradually decreased, while elongation at break improved. Additionally, water uptake, water vapor transmission rate, and oxygen transmission rate all exhibited a declining trend. The films exhibited good biocompatibility, and in the grape preservation experiment, HFBC treatment effectively delayed grape aging and deterioration while enhancing quality preservation. These results suggest that HFBC film holds promising potential for food packaging applications.

Relationship between Structure and Properties of Bio-Based Aromatic Ionic Liquids for Tribological Applications

This study examined six phosphonium-based room-temperature ionic liquids (PRTILs) having trihexyltetradecyl- or tributyltetradecyl-phosphonium cations with saccharinate, salicylate, or benzoate anions, and obtained a feature parameter to correlate their cationic chain length, anionic ring size, and contact angle with tribological properties. PRTILs with trihexyltetradecyl-phosphonium cations had lower coefficient of friction (COF) and wear than PRTILs with tributyltetradecyl- phosphonium cations, a trend attributed to the additional methylene groups providing lower contact angle. For either cation, PRTILs with the saccharinate anion exhibited much lower COF and wear than single-ring anions, due to the formation of a low-shear-strength-tribofilm facilitated by the double-ring structure and sulfur of saccharinate. Overall, this study revealed PRTIL interfacial mechanisms that can be used to identify anion-cation combinations with optimal tribological performance.

Exploring the ring-opening metathesis polymerization process by kinetic Monte Carlo simulation

Investigating the kinetics of polymerization reactions is a powerful tool to obtain information for the engineering design of such processes. It provides insights into how the relative rates of elementary reactions which influence both the kinetics of the reactions and thus characteristics of the products as well, particularly when the reaction parameters of these reactions are unknown. Among polymerization processes, ring-opening metathesis polymerization (ROMP) has gained broad academic and industrial interest, due to its mild conditions to obtain a wide range of polymer products. In this study, kinetic Monte Carlo simulation was applied to reveal the effect of the elementary reactions of ROMP on the kinetics and product distribution. Both the propagation and the cross-metathesis reactions were considered, with the latter leading to the formation of various types of macrospecies whose population levels were also monitored. Relevant tendencies were observed regarding how the variations in the reaction parameters of the elementary reactions of this polymerization process, such as reaction probabilities, monomer addition method, catalyst-to-monomer ratio, and reaction time, affect the kinetics of the polymerization process and the product distributions. These variations also influence the key macromolecular parameters of the resulting polymeric materials, including chain length distribution (CLD), population levels, and polymer functionalities. The results of this study indicate that this simulation technique is a valuable tool for mapping the tailoring possibilities of modifying the reaction parameters of ROMP to achieve desired properties. These properties include number average molecular weight, polydispersity, chain end functionality, and macrocycle-free products.

Mechanochemical Controlled Radical Polymerization: From Harsh to Mild.

Mechanochemistry constitutes a burgeoning field that investigates the chemical and physicochemical alterations of substances under mechanical force. It enables the synthesis of materials which is challenging to obtain via thermal, optical or electrical activation methods. In addition, it diminishes reliance on organic solvents and provides a novel route for green chemistry. Today, as a distinct branch alongside electrochemistry, photochemistry, and thermochemistry, mechanochemistry has emerged as a frontier research domain within chemistry and material science. In recent years, the intersection of mechanochemistry with controlled radical polymerization has witnessed rapid advancements, providing new routes to polymer science. Significantly, we have experienced breakthroughs in methods relying on sonochemistry, piezoelectricity and contact electrification. These methodologies not only facilitate the synthesis of polymers with high molecular weight but also enable precise control over polymer chain length and structure. Transitioning from harsh to mild conditions in mechanochemical routes has facilitated a significant improvement in the controllability of mechanochemical polymerization. From this perspective, we introduce the progress of mechanochemistry in controlled radical polymerization in recent years, aim to clarify the historcial development of this topic.

Structure Assessment and Impacts of Lipids' Chemistry on the Structuration of Polyhydroxyalkanoate Biosynthesized by Bacillus licheniformis AZU-A5.

The current study exploited cheese whey supernatant (CWS) as a renewable resource for polyhydroxyalkanoates (PHAs) formation. Structure identification and investigating the influence of lipid membranes' chemistry on PHA structuration were detailed. Approximately 66 bacterial isolates from dairy products companies in Egypt were screened for PHA production, and the bacterial isolate AZU-A5, identified as Bacillus licheniformis strain AZU-A5, showed the highest production PHA 0.93 g L-1) using whey lactose. The highest PHA rate in the individual design was 1.59 g L-1 with a recovery yield of 33.08% (w w-1), while the production rate in the statistical design reached 1.75 g L-1 PHA and 51.60% PHA content. Structurally, the PHA was identified as polyhydroxy-3R-butyrate (R-PH3B). The fibrous texture by SEM highlighted the self-assembly of PHB. The CD analysis of the PHA films suggested favorable hydrophobic interactions between lipids and PHB. Higher lipid contents not only caused a decrement in the CD signal of PHB but also bathochromic effects occurred. The chain length of lipids exerted high impacts on interactions (CD) and structuration of PHB (Δλ). The unsaturation showed little influence on CD and negligible effect on Δλ, while the head group exerted no effect on CD with a considerable impact on Δλ.

Simultaneous determination of 102 synthetic cannabinoids in electronic cigarette oil by liquid chromatography-tandem mass spectrometry

Synthetic cannabinoids (SCs), which are among the most widely abused new psychoactive substances, are much more potent and have greater efficacy than natural cannabis. SCs can be disguised in various ways and are commonly sold in the form of electronic cigarette oil. SCs belong to a large family with structures consisting of a core with substituents, linker, ring with substituents, and tail. New SCs can be developed by adding substituents, such as halogen, alkyl, and alkoxy groups, to the aromatic ring system or by changing the alkyl chain length. Since the emergence of so-called first-generation SCs, subsequent developments have led to eighth-generation indole/indazole amide-based SCs. As of July 1, 2021, the entire category of SCs was added to the list of controlled substances, but implementation requires urgent improvements in detection technologies. Typically, each method is limited to a few SCs. Owing to the vast number of chemically diverse SCs and their fast update speed, the determination and identification of various types of SCs using a single method is challenging. Therefore, rapid, sensitive, and accurate quantitative methods that includes various types of SCs must be developed to meet the demand for the qualitative and quantitative analysis of new SCs in seized electronic cigarette oil. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of 102 SCs in electronic cigarette oil. The mass spectrometry and liquid-phase conditions influencing SC separation and determination were optimized. Using the external standard method, 102 SCs were successfully identified in electronic cigarette oil. The samples were extracted using methanol. Target analytes were separated on a Shimadzu Shim-pack GIST-HP C18 AQ column (100 mm×2.1 mm, 1.9 μm) at a column temperature of 40 ℃. The mobile phases consisted of (A) 0.1% formic acid aqueous solution and (B) methanol-acetonitrile (1∶1, v/v). The gradient elution conditions were as follows: 0-8 min, 55%A-15%A; 8-15 min, 15%A; 15-16 min, 15%A-55%A; 16-18 min, 55%A. The flow rate was 0.4 mL/min and the injection volume was 1 μL. Operating in the multiple reaction monitoring mode, the 102 SCs were identified within 18 min. Each SC exhibited a good linear relationship in the range of 1-100.0 μg/L with a correlation coefficient (r)≥0.9915. The limits of detection were 0.01-0.30 μg/L and the limits of quantification were 0.04-0.99 μg/L, which meet the requirements for analyzing SCs in actual samples. Precision was determined using standard solutions with 2, 10, and 50 μg/L of the SCs. The precisions (n=6) were 0.3%-6.0%. The recoveries of the 102 SCs, as evaluated by spiking electronic cigarette oil at low (2 μg/mL), medium (10 μg/mL), and high (50 μg/mL) levels, were 80.1%-119.8%. Good performance was observed for the analysis of real samples. The developed method is accurate, rapid, sensitive, and effective for the determination of the 102 SCs in electronic cigarette oil, satisfying the requirements for practical qualitative and quantitative analysis.

Effect of alkyl chain length on the dielectric and electro-optical properties of graphene quantum dots doped cyanobiphenyl based nematic liquid crystals composites

The effects of alkyl chain length and doping of biocompatible/eco-friendly graphene quantum dots (GQDs) at 0.5 wt% on the dielectric and electro-optical properties of cyanobiphenyl (nCB, n = 5, 7) nematic liquid crystals (NLCs) are investigated using optical polarising microscope, electro-optical and dielectric spectroscopic techniques. Our results revealed that GQDs modulated the dielectric and electro-optical properties of nCB. Optical textural studies confirmed the uniform dispersion of GQDs in both NLCs (5CB and 7CB). The threshold voltage evaluated from voltage-dependent optical transmission was found to decrease by 16 % and 6 % in GQDs-5CB and GQDs-7CB composites compared to pure NLCs, respectively. The increment in birefringence by 2 % and 1.3 % and order parameter by 4 % and 0.6 % in GQDs composites with 5CB and 7CB, respectively was observed. Both transverse and longitudinal components of the dielectric permittivity (εˈ⊥ and εˈ∥) showed positive increments of 12 % and 5.4 % in GQDs-5CB composite as compared to pure 5CB. However, the increment was found to be 8.9 % and 4.1 % in GQDs-7CB composite. The GQDs-7CB composite exhibited fewer noticeable changes due to the stronger interaction between the molecules, as compared to GQDs-5CB composite. Our results showed that dispersion of GQDs and the number of carbon atoms ‘n’ in the alkyl chain of CB’s constituent molecules affects their properties, such as display parameters and mesophase stability of 5CB and 7CB homologues. Such GQDs-NLCs composites would be certainly useful in the tunable electrical and electro-optical devices.

Optimizing Environmentally-Friendly oil Recovery: Synergies of Imidazolium-Based ionic liquids and carboxymethylcellulose hydrogels

This research focuses on the combined effectiveness of imidazolium-based ionic liquids (ILs) with triflate anion and carboxymethylcellulose-based hydrogels (CBHs) for environmentally friendly oil recovery. The selection of ILs was based on a review of existing literature, and their performance in extreme reservoir conditions was evaluated by studying parameters like concentration, salinity, temperature, and alkyl chain length. A new material,ionic liquid based CBH (CBHIL), was synthesized by incorporating ILs into hydrogels, and its structure was analyzed using various tests including FTIR, TGA, rheology, and SEM morphology tests. To evaluate the performance in EOR processes, particularly in carbonate rocks, a multilayer glass micromodel with permeabilities was designed. The objective was to determine the water-absorbing capacity, equilibrium swelling, and contact angle change, ultimately leading to increased oil recovery. The results indicated that 1-hexyl-3-methylimidazolium triflate (IL6) was able to reduce interfacial tension (IFT) to a minimum of 6.5 mN/m, surpassing 1-butyl-3-methylimidazolium triflate (IL4), especially at high temperatures and salinity. The emulsion stability of IL6 in the oil phase was also confirmed. CBH was used as a carrier for ILs, exhibiting thermal resistance up to 120 °C. Its porous structure and significant equilibrium swelling of up to 1550 % under harsh reservoir conditions were observed. By incorporating IL in the CBHIL-C6 structure, the linear viscoelastic range of CBH increased from 52.2 % to 170 % strain, and effectively altered carbonate rocks to become completely water-wet, reducing the contact angle from 115.4° to 44.62°. The combination of these two substances led to a maximum recovery of 79.85 % of the original oil in place, a significantly superior outcome compared to separate injection of the substances. Thus, these new compounds demonstrate promising potential for EOR applications in challenging reservoir conditions.

Phosphorus-nitrogen-containing flame-retardant plasticizers derived from L-lactic acid for poly (lactic acid) improved toughness, flame retardancy and crystallization

Designing highly-effective and environmentally friendly biobased flame-retardant plasticizers for polylactic acid (PLA) remains a formidable challenge. In this study, we synthesized four novel phosphorus-nitrogen-containing L-lactic acid-based flame-retardant plasticizers with adjustable chemical structures and phosphorus content, designated as NPDL-Cn, where ’n’ corresponds to the alkyl groups numbers in the alkylamine chain (with n = 4, 6, 8, and 10). Incorporating NPDL-Cn into the PLA matrix offered a twofold benefit, significantly enhancing both the flame retardancy and toughness of PLA. Remarkably, as incorporating 20 phr NPDL-Cn, the resulting blends all achieved UL-94 V-0 grade, and their limiting oxygen index reached about 30.8 %, 29.5 %, 28.3 % and 27.2 %, respectively. A comprehensive analysis of the volatile gases and char layer generated during combustion showed that the flame-retardant mechanism of NPDL-Cn in PLA significantly influenced both the condensed-phase and gas-phase behavior. Meanwhile, NPDL-Cn effectively overcame the brittleness and rigidity of PLA, thus realizing the enhancement of its toughness. In particular, as compared to a mere 3.7 % and 1.7 MJ/m3 for neat PLA, when the methylene numbers of NPDL-Cn were 4, the elongation at break and tensile toughness of the PLA/NPDL-C4 exhibited a substantial increase to 180.1 % and 43.4 MJ/m3, respectively, due to the best interfacial tension of NPDL-C4 with PLA matrix. Additionally, while the tensile strength of neat PLA is notably high at 50.7 MPa, the introduction of PLA/NPDL-C4 results in a significant decrease to 26.3 MPa. Interestingly, biodegradation experiments showed that NPDL-C4 was decomposed into non-toxic and harmless small molecules. This study presents a method for constructing toughened and flame-retardant PLA blends by modulating the alkyl chain length of flame-retardant plasticizers and elucidating their structure–property relationships.

Organic petrographic and geochemical insights into organic matter derived from land plants and marine algae in the Lark Formation, Danish North Sea

Climatic fluctuations from the Eocene to the Miocene highlight the importance of investigating the paleoenvironment of the latest Eocene to the Middle Miocene Lark Formation in the Danish North Sea. This study investigates immature sedimentary organic matter in the Lark Formation using 54 cuttings samples and one core sample collected from seven wells in the eastern North Sea Basin. Organic petrography and molecular geochemistry analyses were performed to determine the variations in the quantity and origin of allochthonous and autochthonous organic matter. Additionally, the study assesses the impact of climate fluctuations on marine productivity in the eastern North Sea Basin and land plant vegetation at the basin margins during the latest Eocene to the Middle Miocene.The organic matter in the Lark Formation originated from mixed sources, primarily land plants, with a secondary contribution from marine algae. This is indicated by the maceral composition and the types and abundance of aliphatic and aromatic hydrocarbon biomarker compounds. Moreover, the presence of diterpenoids (gymnosperm biomarkers) and non-hopanoid triterpenoids (angiosperm biomarkers) reveals that the allochthonous organic matter originated from conifers and angiosperms.Climatic impacts on land plants and marine algae during the latest Eocene to the Middle Miocene are revealed by several parameters: the Averaged Chain Length (ACL) of land plant waxes, the proportion of coniferous contribution (C/(C + A)), and the whole rock volume percentages of huminite, inertinite (H + I, vol%) and liptinite (L, vol%). The shifts to cooler and drier climates highlighted the cold adaptation of onshore conifers and resulted in the input of higher molecular weight waxy components into the sediments. However, under these conditions, reduced precipitation and runoff resulted in lower amounts of terrigenous organic matter supplied to the basin. Additionally, the drop in water temperature and the warm-affinity of local algae assemblage led to reduced marine productivity. Together, these factors contributed to an overall decrease in organic richness. In contrast, during shifts to warmer and more humid climates, the trend reversed. The contribution of conifers to the floral assemblage diminished, but higher amounts of terrigenous organic matter were transported to the basin due to increased precipitation and runoff. This was accompanied by warmer water temperatures, boosting the productivity of organic-walled microplankton in the marine environment and contributing to greater organic richness.

Modulating the carbon chain length of organic phosphine for the selective Au(I) recovery from a copper-ammonia-thiosulfate leaching solution

The selective recovery of gold ions from gold leaching solutions limits the industrial application of the copper-ammonia (Cu2+–NH3)-thiosulfate system. Here, the influence of the carbon chain length of organic phosphines on the selective recovery of gold ions was studied, and an extractant (trihexylphosphine, THP) that is suitable for the selective recovery of gold ions from a Cu2+–NH3-thiosulfate leaching solution was screened. The selectivity of organic phosphines with different carbon chain lengths for gold ions was C8 = C6 > C4 > C3 > C2, and when the number of carbon atoms in a single carbon chain was at least six, the selective recovery of gold ions from the Cu2+–NH3-thiosulfate solution was realized. THP completely recovered low concentration gold ions (6.73 mg/L) in the Cu2+–NH3-thiosulfate gold leaching solution regardless of the pH. The mechanism of gold ion extraction into the organic phase mainly involved ligand exchange between THP and [Au(S2O3)2]3−. Job’s method and density functional theory calculations confirmed that the composition ratio of the complex formed by THP and Au was 2:1 at the practical and theoretical levels, respectively. Finally, Multiwfn and VMD were used to visually predict the possible reaction sites in THP. This study provides an exact method for the selective recovery of gold ions from thiosulfate-based gold leaching solutions, which will promote the development of thiosulfate-based gold leaching systems

Lesional Psoriasis is Associated With Alterations in the Stratum Corneum Ceramide Profile and Concomitant Decreases in Barrier Function.

Psoriasis is an inflammatory skin disease associated with an impaired skin barrier. The skin barrier function is dependent on the extracellular lipid matrix which surrounds the corneocytes in the stratum corneum. Ceramides comprise essential components of this matrix. Alterations in the stratum corneum ceramide profile have been directly linked to barrier dysfunction and might be an underlying factor of the barrier impairment in psoriasis. In this study, we investigated the ceramide profile and barrier function in psoriasis. Lesional and non-lesional skin of 26 patients and 10 healthy controls were analysed using in-depth ceramide lipidomics by liquid chromatography-mass spectrometry. Barrier function was assessed by measuring transepidermal water loss. Lesional skin showed a significant decrease in the abundance of total ceramides with significant alterations in the ceramide subclass composition compared to control and non-lesional skin. Additionally, the percentage of monounsaturated ceramides was significantly increased, and the average ceramide chain length significantly decreased in lesional skin. Altogether, this resulted in a markedly different profile compared to controls for lesional skin, but not for non-lesional skin. Importantly, the reduced barrier function in lesional psoriasis correlated to alterations in the ceramide profile, highlighting their interdependence. By assessing the parameters 2 weeks apart, we are able to highlight the reproducibility of these findings, which further affirms this connection. To conclude, we show that changes in the ceramide profile and barrier impairment are observed in, and limited to, lesional psoriatic skin. Their direct correlation provides a further mechanistic basis for the concomitantly observed impairment of barrier dysfunction.