Amide Research Articles

Endogenous Cannabinoids in Crohn’s Disease

Background: An increasing number of people around the world suffer from Crohn’s disease (CD), one of the inflammatory bowel diseases (IBDs). Recent evidence suggests that the endogenous cannabinoid system plays an important role in IBD. The main endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), are ligands of the CB1 and CB2 receptors that are expressed on immune cells. These receptors as well as endocannabinoids are believed to mediate inflammatory activity and participate in the pathophysiology of CD. Objective: Very little is known about the secretion of endogenous cannabinoids throughout the course of CD. Therefore, the aim of this study was to determine and analyze the 2-AG and AEA concentrations in children who suffered from CD. Methods: We studied 34 adolescents with CD, mean age 13.5 years ± 2.0. Blood samples were collected three times in the active phase of the disease (during admission to hospital, before treatment), 2–4 weeks later, during the treatment and clinical improvement of the patients, and 3–6 months later, in the period of remission. The control group included 33 healthy teenagers of the same age who were examined once. In all patients, fasting blood samples were collected in the morning. 2AG and AEA concentrations in serum were measured using EIA kits (Abclonal, Woburn, MA, USA and ELK Biotechnology Co., Ltd. Wuhan, China, respectively). Results: The median 2-AG concentration in the study group was stable: acute phase 907.4 [379.3; 1300.5] pg/mL, during treatment 715.1 [416.7; 1302.5] pg/mL; remission 991.1 [381.1; 1652.5] pg/mL, and similar to the values observed in the control group 761.8 [504.3; 1497.0] pg/mL. No significant differences were found between the results obtained at all time points in the study group and compared to the control group (in all cases p > 0.44). In the case of AEA, in the study group before treatment, the median concentration was 2.63 [2.24; 2.79] ng/mL and similar to values obtained during treatment 2.56 [2.33; 3.06] ng/mL, and in remission, with 2.61 [2.46; 2.85] ng/mL. All these concentrations were lower compared to the values measured in the control group of 3.18 [2.57; 3.88] ng/mL (p = 0.023, p = 0.035, p = 0.056, respectively). Conclusions: While 2-AG levels remained stable throughout the disease course and were comparable to controls, AEA concentrations were consistently lower in CD patients. Therefore, therapeutic interventions aimed at increasing AEA-related signaling, such as administration of its analogues or fatty acid amide hydrolase inhibitors, may improve symptoms associated with Crohn’s disease in children.

How Great was the “Great Oxidation Event”?

Geochemical sleuthing amid acid mine runoff suggests that scientists should rethink an isotope signal long taken to indicate low levels of atmospheric oxygen in Earth’s deep past.

Rheological behaviour of modified binders for different loading conditions and temperatures: A case of using pig tallow and crumb rubber from end–of–life tyres

This study investigates alternatives to Styrene-Butadiene-Styrene (SBS) polymer in asphalt mixtures by evaluating End-Of-Life tire (ELT) crumb rubber (CR) and fatty acid amide wax (FAA) derived from pig tallow. The research focuses on triple modification of binders with SBS, ELT and FAA to improve performance and reuse waste and industrial by-products in an economical and environmentally responsible manner. The results show that the incorporation of ELT and FAA significantly reduces the SBS content, achieving a 73 % improvement in elastic performance according to Multiple Stress Creep Recovery (MSCR) tests. In addition, this combination improves peak stress and fatigue life in Linear Amplitude Sweep (LAS) tests, demonstrating potential benefits in asphalt mixtures. The study concludes that the combination of pig tallow and end-of-life tire materials doubles the yield energy (Yield Energy of Asphalt Binders, BYET) compared to samples with higher SBS content. In particular, a modification with 6 % CR, 3 % SBS and 2 % FAA doubles the toughness (Er) of a binder with 5 % SBS. This contributes to higher tensile strength in asphalt mixtures, promoting sustainability and efficiency in the road construction industry. This study provides a deeper understanding of how the combination of ELT, FAA and SBS can optimize the properties of asphalt mixtures, highlighting the potential of these additives to improve performance, reduce costs and minimize environmental impact.

The Predictive Value of Plasma Bioactive Lipids on Craving in Human Volunteers With Alcohol Use Disorder

BackgroundAlcohol use disorder (AUD) is a chronic relapsing disorder characterized by alcohol seeking and consumption despite negative consequences. Despite the availability of multiple treatments, patients continue to exhibit high relapse rates. Thus, biomarkers that can identify patients at risk for heightened craving are urgently needed. Mounting preclinical and clinical evidence implicates perturbations in bioactive lipid signaling in the neurobiology of craving in AUD. We hypothesize that these lipids are potential biomarkers for predicting alcohol craving in patients with AUD. MethodsThis study used archival deidentified clinical data and corresponding plasma specimens from 157 participants in 3 clinical studies of AUD. We evaluated plasma levels of 8 lipid species as predictors of craving in response to in vivo alcohol and affective cues during abstinence. ResultsParticipants were 109 men and 48 women who met DSM-5 criteria for severe AUD. We found that plasma levels of 12- and 15-HETE, 12/15-lipoxygenase–produced proinflammatory lipids, and palmitoylethanolamide, an anti-inflammatory fatty acid amide hydrolase–regulated lipid metabolite, were differentially correlated with alcohol craving during abstinence, predicting higher craving independent of demographics, alcohol use history, and multiple therapeutic treatments. ConclusionsOur findings highlight the promise of these lipid metabolites as biomarkers of heightened alcohol craving. The results open a novel opportunity for further research and clinical evaluation of these biomarkers to optimize existing treatments and develop new therapeutics for AUD.

Development of a Novel, Easy-to-Prepare, and Potentially Valuable Peptide Coupling Technology Utilizing Amide Acid as a Linker.

The process of synthesizing radionuclide-coupled drugs, especially shutdown technology that links bipotent chelators with biomolecules, utilizes traditional coupling reactions, including emerging click chemistry; these reactions involve different drawbacks, such as complex and cumbersome reaction steps, long reaction times, and the use of catalysts at various pH values, which can negatively impact the effects of the chelating agent. To address the above problems in this study, This research designed a novel bipotent chelator coupled with peptides. In the present study, dichloromethane was used as a solvent, and the reaction was conducted at room temperature for 12 h. A one-step ring-opening method was employed to introduce the coupling functional group of tridentate amide acid. The coupling materials consisted of the amino active site of the peptide and diethylene glycol anhydride. In this paper, this study explored the reactions between different equivalents of acid anhydride coupled to the peptide (peptide sequence: HLRKLRKR) and determined that the maximum conversion of the peptide feedstock was 87%. To determine the selectivity of the reaction sites in this polypeptide, This study identified the peptide sequence at the reaction site using nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS). For the selected peptide, the first reactive site was on the terminal amino group, followed by the amino group on the tetra- and hepta-lysine side chains. The tridentate amic acid framework functions as a chelating agent, capable of binding a range of lanthanide ions. This significantly reduces and optimizes the time and cost associated with synthesizing radionuclide-coupled drugs.

Modulation of the Adjuvant Potential of Imidazoquinoline-Based TLR7/8 Agonists via Alum Adsorption.

Toll-like receptor (TLR)-7/8 agonists are promising candidates for the development of new-generation vaccine adjuvants. Adsorption of TLR7/8 agonists on aluminum salts (alum) may further enhance vaccine immunogenicity. Evaluation of the adjuvanticity of the most active dual TLR7/8 agonists, 1-(3-(aminomethyl)benzyl)-2-butyl-1H-imidazo[4,5-c]quinolin-4-amine (m-AM-BBIQ, 10) and its para derivative p-AM-BBIQ (11), along with their gallic acid and protocatechuic acid amides in a recombinant-protein-based COVID-19 vaccine platform confirmed the importance of vic-polyphenolic functionality in TLR7/8 agonists for the alum adsorption, thereby resulting in a balanced Th1/Th2 immune response. A novel 7,8-dihydroxy-IMDQ derivative (dh-p-AM-BBIQ, 21) was designed wherein the vic-diphenolic functionality was introduced in the quinoline ring of the imidazo[4,5-c]quinoline scaffold. Compound 21 not only retained the TLR7 agonistic activity (EC50 = 3.72 μM) but also showed high adsorption to alum and induced a potent antibody response to SARS-CoV-2 spike protein and hepatitis B surface antigen immunized mice. The combination adjuvant comprising compound 21 adsorbed to alum represents a promising candidate for further development as a human and veterinary vaccine adjuvant.

Fluorescence-Based Enzyme Activity Assay: Ascertaining the Activity and Inhibition of Endocannabinoid Hydrolytic Enzymes.

The endocannabinoid system, known for its regulatory role in various physiological processes, relies on the activities of several hydrolytic enzymes, such as fatty acid amide hydrolase (FAAH), N-acylethanolamine-hydrolyzing acid amidase (NAAA), monoacylglycerol lipase (MAGL), and α/β-hydrolase domains 6 (ABHD6) and 12 (ABHD12), to maintain homeostasis. Accurate measurement of these enzymes' activities is crucial for understanding their function and for the development of potential therapeutic agents. Fluorometric assays, which offer high sensitivity, specificity, and real-time monitoring capabilities, have become essential tools in enzymatic studies. This review provides a comprehensive overview of the principles behind these assays, the various substrates and fluorophores used, and advances in assay techniques used not only for the determination of the kinetic mechanisms of enzyme reactions but also for setting up kinetic assays for the high-throughput screening of each critical enzyme involved in endocannabinoid degradation. Through this comprehensive review, we aim to highlight the strengths and limitations of current fluorometric assays and suggest future directions for improving the measurement of enzyme activity in the endocannabinoid system.

Genetic Variation and Stroke Recovery: The STRONG Study.

Genetic association studies can reveal biology and treatment targets but have received limited attention for stroke recovery. STRONG (Stroke, Stress, Rehabilitation, and Genetics) was a prospective, longitudinal (1-year), genetic study in adults with stroke at 28 US stroke centers. The primary aim was to examine the association that candidate genetic variants have with (1) motor/functional outcomes and (2) stress-related outcomes. For motor/functional end points, 3 candidate gene variants (ApoE ε4, BDNF [brain-derived neurotrophic factor], and a dopamine polygenic score) were analyzed for associations with change in grip strength (3 months-baseline), function (3-month Stroke Impact Scale-Activities of Daily Living), mood (3-month Patient Health Questionnaire-8), and cognition (12-month telephone-Montreal Cognitive Assessment). For stress-related outcomes, 7 variants (serotonin transporter gene-linked promoter region, ACE [angiotensin-converting enzyme], oxytocin receptor, FKBP5 [FKBP prolyl isomerase 5], FAAH [fatty acid amide hydrolase], BDNF, and COMT [catechol-O-methyltransferase]) were assessed for associations with posttraumatic stress disorder ([PTSD]; PTSD Primary Care Scale) and depression (Patient Health Questionnaire-8) at 6 and 12 months; stress-related genes were examined as a function of poststroke stress level. Statistical models (linear, negative binomial, or Poisson regression) were based on response variable distribution; all included stroke severity, age, sex, and ancestry as covariates. Stroke subtype was explored secondarily. Data were Holm-Bonferroni corrected. A secondary replication analysis tested whether the rs1842681 polymorphism (identified in the GISCOME study [Genetics of Ischaemic Stroke Functional Outcome]) was related to 3-month modified Rankin Scale score in STRONG. The 763 enrollees were 63.1±14.9 (mean±SD) years of age, with a median initial National Institutes of Health Stroke Scale score of 4 (interquartile range, 2-9); outcome data were available in n=515 at 3 months, n=500 at 6 months, and n=489 at 12 months. At 1 year poststroke, the rs6265 (BDNF) variant was associated with poorer cognition (0.9-point lower telephone-Montreal Cognitive Assessment score, P=1×10-5). For stress-related outcomes, rs4291 (ACE) and rs324420 (FAAH) were risk factors linking increased poststroke stress with higher 1-year depression and PTSD symptoms (P<0.05), while rs4680 (COMT) linked poststroke stress with lower 1-year depression and PTSD. Findings were unchanged when considering stroke subtype. STRONG replicated GISCOME: rs1842681 was associated with lower 3-month modified Rankin Scale score (P=3.2×10-5). This study identified genetic associations with cognitive function, depression, and PTSD 1 year poststroke. Genetic susceptibility to PTSD and depressive symptoms varied according to the amount of poststroke stress, underscoring the critical role of lived experiences in recovery. Together, the results suggest that genetic association studies provide insights into the biology of stroke recovery in humans.

Hydrogen-bonding enhanced current-carrying tribological properties based on ricinoleic acid amides

Load-carrying capacity and electrical stability are important factors in evaluating the performance of conductive grease. In this paper, a non-soap conductive grease is prepared to simultaneously enhance the wear resistance and conductivity of copper-copper friction pairs. Experimental results show that compared with AnRunt commercial grease, the COF of conductive grease with ricinoleic acid amide thickener is reduced by 43 %, the wear rate is reduced by 69 %, and the contact resistance decreases by 26 %. The introduced hydrogen bonds have a positive effect on friction reduction, anti-wear and conductivity. The conductive grease prepared in this paper provides a new perspective for the development of innovative conductive grease.

Low dielectric constant composites using covalent organic framework dispersed terpolyimide

AbstractPolyimides are used in various applications, including fuel cells, membranes, and microelectronics, due to their outstanding tensile properties, great thermal stability, low dielectric constant, and chemical inertness. Applications requiring even lower dielectric constants include interlayer dielectrics and tape‐automated bonding. In this study, a covalent organic framework (COF‐1) was synthesized and dispersed in various percentages into a solution of terpoly(amide acid) (TPAA) to produce COF‐1/terpolyimide composites. 3,3′,4,4′‐Oxydiphthalic dianhydride (ODPA), 3,3′,4,4′‐biphenyltetracarboxylicdianhydride (BPDA), and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) were reacted with 4,4′‐(hexafluoroisopropylidene)bis[(4‐aminophenoxy)benzene] (HFBAPP) or 4,4′‐(hexafluoroisopropylidene) dianiline (6FpDA) to form terpoly(amide acid). In this case, monomers with fluorinated substituents (HFBAPP, 6FpDA, and 6FDA) were utilized to improve free volume. Pores of COF‐1 and gaps between polyimide chains and COF‐1 can be filled with air with a dielectric constant (κ) ~1, lowering the κ value of terpolyimide composites. The κ value of COF‐1/terpolyimide composites decreased as COF‐1 content increased, reaching a minimum of 1.96. Tensile properties decreased slightly with increasing COF‐1 levels. The terpolyimides and their composites were thermally stable up to approximately 520°C. As a result, these polymer composites look promising for use as insulators in microelectronic applications.Highlights Terpolyimide is prepared using fluorinated monomers to improve bulk volume. Incorporated COF‐1 into terpoly(amide acid) to introduce pores/voids and reduce dielectric constant. Developed COF‐1/terpolyimide composites with a low dielectric constant of 1.96. Optimized COF‐1/terpolyimide composites for microelectronic applications.

Genetic Evidence of Endocannabinoid System on Perceived Stress and Restricted Food Intake: The Role of Variants rs324420 in FAAH Gene and rs1049353 in CNR1 Gene.

Background: The endocannabinoid system (ECS) is active in brain regions involved in stress, food intake, and emotional regulation. The CB1 receptor and the fatty acid amide hydrolase (FAAH) enzyme regulate the ECS. Genetic variants in the FAAH gene (rs324420) and in the CNR1 gene (rs1049353) have been involved in both chronic stress and obesity. As a maladaptive strategy to evade the stress, three dysfunctional eating patterns may appear: cognitive restriction, disinhibition, and emotional eating. Aim: To evaluate the association of variants rs324420 in the FAAH gene and rs1049353 in the CNR1 gene with perceived stress, dysfunctional eating patterns, and anthropometric and body composition variables. Methods: This cross-sectional study included 189 participants from western Mexico. The Spanish version of the Three-Factor Eating Questionnaire and the Perceived Stress Scale were applied. Genotyping was performed with TaqMan® probes. Results: It was found that subjects with CA/AA genotypes in FAAH had a higher risk of presenting high scores in stress perception than CC genotype carriers (odds ratio [OR] 1.85, 95% confidence interval [CI] 1.007-3.339; p = 0.048); in addition, the CC genotype of this genetic variant was related to higher body weight and body fat, but no association was found with dysfunctional eating patterns. As for the CNR1 single-nucleotide polymorphism, this variant showed no significant association with stress perception scores, but subjects with GA/AA genotypes in CNR1 had a lower risk of presenting high scores of restriction in food intake compared with GG genotype carriers (OR 0.11, 95% CI 0.046-0.322; p < 0.001). Therefore, this study suggests a differential role of the ECS genes FAAH and CNR1 in perceived stress and dysfunctional eating patterns, respectively. Further studies in other populations are required.

Fatty Acid Amides Suppress Proliferation via Cannabinoid Receptors and Promote the Apoptosis of C6 Glioma Cells in Association with Akt Signaling Pathway Inhibition.

A glioma is a type of tumor that acts on the Central Nervous System (CNS) in a highly aggressive manner. Gliomas can occasionally be inaccurately diagnosed and treatments have low efficacy, meaning that patients exhibit a survival of less than one year after diagnosis. Due to factors such as intratumoral cell variability, inefficient chemotherapy drugs, adaptive resistance development to drugs and tumor recurrence after resection, the search continues for new drugs that can inhibit glioma cell growth. As such, analogues of endocannabinoids, such as fatty acid amides (FAAs), represent interesting alternatives for inhibiting tumor growth, since FAAs can modulate several metabolic pathways linked to cancer and, thus, may hold potential for managing glioblastoma. The aim of this study was to investigate the in vitro effects of two fatty ethanolamides (FAA1 and FAA2), synthetized via direct amidation from andiroba oil (Carapa guianensis Aublet), on C6 glioma cells. FAA1 and FAA2 reduced C6 cell viability, proliferation and migratory potential in a dose-dependent manner and were not toxic to normal retina glial cells. Both FAAs caused apoptotic cell death through the loss of mitochondrial integrity (ΔΨm), probably by activating cannabinoid receptors, and inhibiting the PI3K/Akt pathway. In conclusion, FAAs derived from natural products may have the potential to treat glioma-type brain cancer.

Evolution and generation mechanism of retained oil in lacustrine shales: A combined ReaxFF-MD and pyrolysis simulation perspective

To accurately investigate the evolution characteristics and generation mechanism of retained oil, the study analyzed organic-rich lacustrine shale samples from the Paleogene Kongdian Formation in Cangdong Sag, Bohai Bay Basin. This analysis involves Rock-Eval pyrolysis, pyrolysis simulation experiments, Gas Chromatograph Mass Spectrometer (GC–MS), and reactive molecular dynamics simulations (ReaxFF). The results revealed the retained oil primarily consisted of n-alkanes with carbon numbers ranging from C14 to C36. The generation of retained oil occurred through three stages. A slow growth stage of production rate was observed before reaching the peak of oil production in Stage I. Stage II involved a rapid increase in oil retention, with C12–C17 and C24–C32 serving as the primary components, increasing continuously during the pyrolysis process. The generation process involved the cleavage of weak bonds, including bridging bonds (hydroxyl, oxy, peroxy, imino, amino, and nitro), ether bonds, and acid amides in the first stage (Ro =0.50%–0.75%). The carbon chains in aromatic ring structures with heteroatomic functional groups breaks in the second stage (Ro =0.75%–1.20%). In the third stage (Ro =1.20%–2.50%), the ring structures underwent ring-opening reactions to synthesize iso-short-chain olefins and radicals, while further breakdown of aliphatic chains occurred. By coupling pyrolysis simulation experiments and molecular simulation technology, the evolution characteristics and bond breaking mechanism of retained oil in three stages were revealed, providing a reference for the formation and evolution mechanism of retained oil.

A Triterpene-Based bioactive drug delivery system for combined chemotherapy of liver cancer

Carrier materials always account for the majority particularly in nanosized formulations, which are administrated along with the active ingredient part might result in metabolism related toxicity. The usage of bioactive excipients could not only reduce the sided effect but also provide additional therapeutic effects. In the present study, a triterpene based micellar drug delivery system was developed using a bioactive solanesol derivative. Solanesylamine was prepared firstly followed by conjugating with poly (ethylene glycol) using maleic acid amide linkage. The amphiphilic drug carrier PEGylated (2-propyl-3-methylmaleic acid)-block-solanesol amine (mPEG-CDM-NH-SOL) could be formed into micelles and loaded with doxorubicin (DOX) inside. The micelles were about 112 nm in size and the drug loading content was about 5.97 wt%. An acid triggered drug release behavior was obviously observed for the DOX loaded pH-sensitive micelle mPEG-CDM-NH-SOL-DOX. While not for DOX-loaded micelles without pH-sensitivity (mPEG-NHS-NH-SOL). CCK8 assay showed that the micelles of PEGylated solanesylamines exhibited certain inhibitory effect on tumor cells at high concentration and the pH sensitive ones seemed more toxic. In vivo studies showed that the pH sensitive mPEG-CDM-NH-SOL-DOX had a superior anti-tumor effect, indicating its great potential in cancer treatment.

Disrupted stress-induced analgesia in a neuropathic pain state is rescued by the endocannabinoid degradation inhibitor JZL195.

Acute stress normally engages descending brain pathways to produce an antinociceptive response, known as stress-induced analgesia. Paradoxically, these descending pain modulatory pathways are also involved in the maintenance of the abnormal pain associated with chronic neuropathic pain. It remains unclear how stress-induced analgesia is affected by neuropathic pain states. We therefore examined the impact of a chronic constriction nerve-injury (CCI) model of neuropathic pain on restraint stress-induced analgesia in C57BL/6 mice. Thirty minutes of restraint stress produced analgesia in the hotplate thermal nociceptive assay that was less in CCI compared to control mice who underwent a sham-surgery. In sham but not CCI mice, stress-induced analgesia was reduced by the opioid receptor antagonist naltrexone. The cannabinoid CB1 receptor antagonist AM281 did not affect stress-induced analgesia in either sham or CCI mice. Low-dose pre-treatment with the dual fatty acid amide hydrolase and monoacylglycerol lipase inhibitor JZL195 increased stress-induced analgesia in CCI but not sham mice. The JZL195 enhancement of stress-induced analgesia in CCI mice was abolished by AM281 but was unaffected by naltrexone. These findings indicate that the acute opioid-mediated analgesic response to a psychological stressor is disrupted in a nerve-injury model of neuropathic pain. Importantly, this impairment of stress-induced analgesia was rescued by blockade of endocannabinoid breakdown via a cannabinoid CB1 receptor dependent mechanism. These findings suggest that subthreshold treatment with endocannabinoid degradation blockers could be used to alleviate the disruption of endogenous pain control systems in a neuropathic pain state.

Metabolomic profiling unravels divergent adaptive responses of oil palm (Elaeis guineensis) seedlings to drought stress under shaded and unshaded conditions

Abstract. Adrian M, Wulandari R, Sembiring E, Natawijaya A. 2024. Metabolomic profiling unravels divergent adaptive responses of oil palm (Elaeis guineensis) seedlings to drought stress under shaded and unshaded conditions. Biodiversitas 25: 2404-2414. This research takes a unique approach by investigating the metabolomic responses of oil palm (Elaeis guineensis Jacq.) seedlings to drought stress under both shaded and unshaded conditions. Drought stress poses a significant threat to oil palm cultivation, with profound implications for global palm oil production. Our study aims to unravel the adaptive mechanisms of oil palm seedlings through metabolomic profiling, specifically focusing on amino acids and isoprenoids. The methodology involved collecting samples at distinct time points, including normal conditions, 7 days after drought stress (7 DAT), and 14 days after drought stress (14 DAT). Gas Chromatography-Mass Spectrometry (GC-MS) was used for comprehensive metabolite analysis. The results unveiled substantial changes in metabolite profiles, particularly in amino acids and isoprenoids, indicating the plant's concerted efforts to maintain biochemical homeostasis and vitality during drought stress. Cluster analysis revealed distinct metabolic responses between shaded and unshaded conditions, suggesting an initial conservative response followed by subsequent adaptive measures over time. The fold-change analysis identified key compounds such as Proline, Methyl Palmitate, and octadecylamine, which are crucial for the plant's adaptation to drought conditions. ROC analysis further confirmed Proline and D-Glucuronic Acid Amide as potential biomarkers for distinguishing plant responses to drought stress. This comprehensive metabolomic investigation provides valuable insights into the adaptive strategies employed by oil palm seedlings, thereby offering practical implications for developing sustainable cultivation practices and mitigating drought stress in oil palm cultivation.

Excellent thermal conductivity and electrical insulation in polyimide/graphene oxide/carbon nanotubes composites

AbstractPolymer composites with heat resistance, good thermal conductivity, and insulation properties can meet the special needs of electronics and electrical appliances. In this work, graphene oxide (GO) and carbon nanotubes (CNTs) are coated by polydopamine (PDA). 4,4′‐diaminodiphenyl ether (ODA), pyromellitic dianhydride (PMDA), and 4,4′‐oxydiphthalic anhydride (ODPA) in‐situ polymerize to prepare poly(amide acid) (PAA) containing thermally conductive yet insulating fillers (PDA@GO, PDA@CNTs). As the concentration of fillers in PI composites increases, the thermal conductivity rises, but the insulation property decreases. Keeping the filler content constant and varying the ratio of PDA@GO and PDA@CNTs, the thermal conductivity increases and then decreases. When PDA@GO and PDA@CNTs have a mass ratio of 10:1, the significant synergistic effect affects the thermal conductivity. The PI/PG10C1–25 sample has a thermal conductivity of 1.46 W/(m·K), which is 6.9 times greater than the pure PI. Additionally, the volume resistivity, dielectric permittivity, and dielectric loss (100 kHz) of PI/PG10C1–25 are 2.8 × 1013 Ω cm, 5.4 and 0.28, respectively. The heat resistance of PI composites is almost the same as that of pure PI. Given these outstanding attributes, the developed PI composites offer vast applications in many fields.Highlights Synergistic PDA@GO and PDA@CNTs (10:1) optimize thermal conductivity. PI/PG10C1–25 achieves 6.9 times higher thermal conductivity than pure PI. Volume resistivity of PI/PG10C1–25 reaches 2.8 × 1013 Ω·cm. Dielectric permittivity of PI/PG10C1–25 reaches 5.4 at 100 kHz. Developed PI composites maintain excellent heat resistance.

Deoxyfluorinated Amidation of Carboxylic Acids Using Pyridinesulfonyl Fluoride

Deoxyfluorinated Amidation of Carboxylic Acids Using Pyridinesulfonyl Fluoride

Monofluorophore-based Two-Photon Ratiometric Fluorescent Probe for the Quantitative Imaging of Fatty Acid Amide Hydrolase in Live Neurons and Mouse Brain Tissues

Monofluorophore-based Two-Photon Ratiometric Fluorescent Probe for the Quantitative Imaging of Fatty Acid Amide Hydrolase in Live Neurons and Mouse Brain Tissues

Ex vivo lipidomics reveal monoacylglycerols as substrates for a fatty acid amide hydrolase in the legume Medicago truncatula.

Fatty acid amide hydrolase (FAAH) is a conserved hydrolase in eukaryotes with promiscuous activity toward a range of acylamide substrates. The native substrate repertoire for FAAH has just begun to be explored in plant systemsoutside the model Arabidopsis thaliana. Here, we used ex vivo lipidomics to identify potential endogenous substrates for Medicago truncatula FAAH1 (MtFAAH1). We incubated recombinant MtFAAH1 with lipid mixtures extracted from M. truncatula and resolved their profiles via gas chromatography-mass spectrometry (GC-MS). Data revealed that besides N-acylethanolamines (NAEs), sn-1 or sn-2 isomers of monoacylglycerols (MAGs) were substrates for MtFAAH1. Combined with in vitro and computational approaches, our data support both amidase and esterase activities for MtFAAH1. MAG-mediated hydrolysis via MtFAAH1 may be linked to biological roles that are yet to be discovered.