Aminocaproic Acid Research Articles

In Silico evaluation of the anti-influenza potential of Streptomyces bioactive compounds

Influenza, a highly contagious respiratory viral disease characterized by its short incubation period and severe symptoms, is treatable with antiviral drugs targeting viremia. Among new antiviral agents, Actinobacteria, particularly from the Streptomyces genus, are notable for their ability to produce potent antiviral compounds. This study evaluates the antiviral potential of Streptomyces sp. KSF 103, isolated from Kuala Sat, Jerantut, Pahang, against the Influenza A virus (IAV). Using molecular docking tools such as AutoDock Vina and PyMOL, the interactions of four compounds – hypoxanthine, vitamin D, purine, and aminocaproic acid – were analyzed against IAV proteins. Vitamin D exhibited the highest binding affinity against H3N2’s M2 (−9.6 kcal/mol) and HA (−9.2 kcal/mol) proteins. Additionally, RMSD dynamics parameters indicated that the best-scoring complexes are predicted to be satisfactorily stable under physiological settings. These findings suggest that Streptomyces sp. KSF 103 could be a promising source for developing new antiviral treatments against influenza.

Effective Pediatric Blood Management in Craniosynostosis Surgery: A Long-Term Update.

Blood transfusion is common in cranial vault surgery, and protocolized efforts to minimize transfusion have been reported in recent years. This study assesses the long term, prospective outcomes of a pediatric blood management protocol for the cranial vault reconstruction (CVR) population. Data from a retrospective control cohort and a prospective cohort employing a protocol for preoperative hematologic optimization of patients undergoing CVR from January 2015 to October 2023 was reviewed. Preoperative hemoglobin (Hgb) determined the preoperative protocol. Intraoperative tranexamic acid (TXA) and/or aminocaproic acid, cell-saver technology, and postoperative iron or erythropoietin alfa supplementation were also used in the protocol. For statistical analysis, P<0.05 was deemed significant. The cohort consisted of 194 successive patients (20 control and 174 treatment). Age, sex, and weight were not significantly different between groups. Mean postoperative Hgb was significantly higher in the control group (P<0.01). No difference was observed in Hgb at discharge between control and treatment groups. Mean estimated blood loss, volume of intraoperative packed red blood cells, rate of packed red blood cell transfusion, and mean total transfusion volume during hospitalization were significantly higher in the control group compared with the treatment group (P<0.01). Mean length of stay did not differ between groups. Efforts to optimize blood management in the CVR population are critical. This prospective study represents a robust and reproducible protocol for pediatric blood management with significant reductions in transfusion requirements.

Optimizing Transfection Efficiency of Spermine Polar Head Cholesterol-Based Cationic Lipids with Amino Acid Linker.

In this work, a series of spermine polar head cholesterol-based cationic lipids with various amino acid spacers were synthesized and evaluated as non-viral gene delivery systems. The physicochemical properties of the resulting lipoplexes, formed from these lipids and DOPE, were assessed, including zeta-potential, DNA binding and DNA protection from serum. Transfection efficiency and cytotoxicity were examined under serum-free and 10-40 % serum-containing conditions. The results showed that the physicochemical properties of cationic lipids, both with and without amino acid spacers, were not significantly different. Cationic liposomes composed of lipid Sper-Ahx-Chol, which has a 6-aminohexanoic acid spacer, and DOPE exhibited greater transfection efficiency in HeLa cells compared to Lipofectamine3000, both in the absence and presence of 10-40 % serum. Additionally, lipid Sper-His-Chol with a histidine spacer and Sper-Ahx-Chol showed higher efficiency than Lipofectamine3000 against HEK293T under 40 % serum conditions. These results suggest that the incorporation of amino acids into the cationic lipids can significantly enhance their DNA delivery efficiency. Specifically, certain amino acid modifications improved transfection efficiency while maintaining low cytotoxicity. Our findings highlight the potential of amino acid-tailored cationic lipids as promising vectors for enhanced DNA delivery.

Inherited Disorders of the Fibrinolytic Pathway: Pathogenic Phenotypes and Diagnostic Considerations of Extremely Rare Disorders

AbstractFibrinolysis is initiated by the activation of plasminogen to plasmin via tissue-plasminogen activator (tPA) and urokinase-plasminogen activator (uPA); plasmin then converts fibrin to fibrin degradation products (FDPs). The antifibrinolytics counterbalancing this system include plasminogen activator inhibitor-1 (PAI-1), which inhibits tPA and uPA, α-2 antiplasmin (α2AP), which inhibits plasmin, and thrombin activatable fibrinolysis inhibitor, which inhibits the conversion of fibrin to FDP. Inherited disorders of the fibrinolytic pathway are rare and primarily have hemorrhagic phenotypes in humans: PAI-1 deficiency, α2AP deficiency, and Quebec platelet disorder. Patients with these disorders are usually treated for bleeds or receive prophylaxis to prevent bleeds in the surgical setting, with pharmacological antifibrinolytics such as aminocaproic acid and tranexamic acid. Disorders of the fibrinolytic pathway with fibrin deposition are extremely rare, mostly noted in patients with plasminogen deficiency, who have more recently benefited from advances in human plasma-derived plasminogen concentrates administered intravenously or locally. These disorders can be very difficult to diagnose using conventional or even specialized coagulation testing, as testing can be nonspecific or have low sensitivity. Testing of the corresponding protein's activity and antigen (where applicable) can be obtained in specialized centres, and routine laboratory measures are not diagnostic. Genetic testing of the pathogenic mutations is recommended in patients with a high suspicion of an inherited disorder of the fibrinolytic pathway.

A comparative metabolomics study of delayed-harvested and pumpkin grafted cucumbers

Cucumber is a widely consumed vegetable crop known for its rich nutrient composition and distinctive flavor, influenced by both volatile and non-volatile compounds. Grafting and delayed harvesting are crucial strategies for increasing cucumber yield. The present study investigates the impact of delayed harvesting at different developmental stages and grafting on the metabolic profile, flavor, and overall quality of cucumber fruits Yuxiu 2 (YX) using UPLC-MS/MS and GC-MS/MS techniques. The results indicate that delayed harvesting of YX led to significant increases in length, diameter, and weight from 12 to 24 days after pollination (DAP), with minimal growth beyond 24 DAP. However, grafting did not affect these physical parameters compared to self-rooted plants. Furthermore, metabolic profiling reveals that delayed harvesting enhances the concentration of certain non-volatile metabolites, including alkaloids, organic acids, and phenolic acids, while leading to a reduction in flavonoid contents. Overall, 140 non-volatile and 26 volatile differential metabolites were screened at three developmental stages. Notably, four new organic acids (6-amino hexanoic acid, 5-amino valeric acid, 1-hydroxy-2-naphthoic acid, and succinic semialdehyde) and three novel alkaloids (3-indole acetonitrile, epinephrine, and serotonin) were identified. Volatile compounds, such as aldehydes, esters, terpenes, alcohols, and ketones, exhibit a peak in concentration at 24 DAP, followed by a decline. The characteristic cucumber flavor compound, (E,Z)-2,6-nonadienal, remains consistent across all developmental stages. In grafted cucumber fruits, a total of 113 non-volatile and 11 volatile differential metabolites were screened, and among them, ten unique non-volatile metabolites were detected in grafted fruits, contributing to the sour and bitter taste of cucumbers. Moreover, some of the metabolites like (1S,4S,4aR)-1-isopropyl-4-methyl-7-methylene-1,2,3,4,4a,5,6,7-octahydronaphthalene with pentylenetetrazol contribute to an undesirable camphor-like odor. The study concludes that while delayed harvesting and grafting practices can increase cucumber yield, they also significantly alter the fruit’s metabolic profile, impacting taste and flavor.

Anti-fibrinolytics for mucosal bleeding in adults with life-limiting illnesses: a systematic review

IntroductionPatients with life-limiting illnesses are at increased risk of mucosal bleeding. Usual management includes anticipatory planning and sedation, alongside anti-fibrinolytics, despite a lack of evidence for their use. Anti-fibrinolytic agents...

The use of fibrinolysis inhibitors in cardiac surgery with cardiopulmonary bypass (literature review)

In cardiac surgery with cardiopulmonary bypass (CPB) is a common complication. The incidence of this complication in cardiac surgery patients is estimated at about 10%. For this reason, the introduction of a patient blood management (PBM) in cardiac surgery is extremely relevant. Antifibrinolytic therapy is a key pharmacological tool of a multimodal PBM in cardiac surgery with CPB. The use of antifibrinolytics (tranexamic acid (TXA) and epsilon aminocaproic acid (EACA)) is standard practice in complex cardiac surgery with CPB. However, there is currently ongoing discussion regarding the search for the optimal dose of EACA and TXA to achieve an effective concentration in blood plasma in order to inhibit fibrinolysis with the minimization of adverse events. The use of aprotinin has a number of potential advantages, but its use in routine clinical practice is significantly limited. This review presents modern approaches to antifibrinolytic therapy, examines the mechanisms of action of the main drugs, highlights the side effects associated with the use of antifibrinolytic agents.

Molecular dynamics simulation of the thermal conductivity mechanism of polydimethylsiloxane composites filled by multilayer hexagonal boron nitride

To design polydimethylsiloxane (PDMS)-based nanocomposites with high thermal conductivity, multiscale simulations were adopted to study the effect of the modified hexagonal boron nitride (h-BN) and the layer number of h-BN on the interface improvement of nanocomposites. The results indicate that 6-aminocaproic acid (ACA) effectively improves the interfacial thermal conductivity of the composites. The interaction energy between h-BN modified by ACA (ACA@h-BN) and PDMS is enhanced compared to that of an unmodified h-BN/PDMS composite system. It's interesting that the change rate of thermal conductivity (δ) decreases first and then increases with the increase in the layer number of ACA@h-BN, and gradually increases to a value more equal to that of the single-layer system when the layer number of ACA@h-BN reaches 5. The interfacial thickness increases from 1.93 Å to 2.60 Å as the layer number of ACA@h-BN increases from 1 to 6, which is beneficial to improve the thermal conductivity. However, the matching coefficient (M) of the phonon vibration power spectrum between PDMS and ACA@h-BN decreases from 0.024 to 0.011 as the layer number of ACA@h-BN increases from 1 to 6, which impairs the thermal conductivity. The decrease in M dominates the δ in the composites filled by h-BN with 1–3 layers. The thermal conductivity is more affected by the specific gravity of ACA@h-BN than M in the composites filled by h-BN with 4–6 layers. It is proposed that the ideal single-layer ACA@h-BN can be replaced to some extent by the ACA@h-BN with 5 layers to improve the thermal properties of the composites. This work is expected to provide theoretical support for interface modification of nanocomposites, and preparation of high-thermal conductivity composites.

Hemostatic Gelatin-Alginate Hydrogels Modified with Humic Acids and Impregnated with Aminocaproic Acid

The work is devoted to the development of safe and biocompatible multicomponent gelatin-alginate hydrogels modified with humic acids (HA) and impregnated with the antifibrinolytic agent aminocaproic acid (АА).These hydrogels are designed to be effective hemostatic materials with anti-inflammatory properties and the ability to deliver in less than 30 seconds to deep and hidden areas of hemorrhages. Studies of the crystal structure by X-ray diffraction analysis and non-covalent interactions of molecules by Fourier transform infrared spectroscopy of the developed hemostatic gelatin-alginate hydrogels modified with bactericidal and anti-inflammatory humic acids made it possible to identify the optimal concentrations of HA from 2.5 wt.%. up to 5 wt.%. At such concentrations of HA, gelatin-alginate hydrogels have a semicrystalline structure. Due to non-covalent bonds between polymer chains, they are thermo-responsive with a gel-sol transition temperature of about 37 °C. Impregnation of these hydrogels with aminocaproic acid led to an almost threefold increase in their swelling, which facilitated the dissolution of AA in the hydrogels and its subsequent delivery to the wound. Experiments simulating the transmembrane transport of aminocaproic acid from the developed gelatin-alginate hydrogels confirmed their ability to rapidly deliver up to 494± 3 mg of AA from 5 ml of hydrogel to the wound.

Effects of Organic Xenobiotics on Tenebrio molitor Larvae and Their Parasite Gregarina polymorpha.

Environmental contamination with xenobiotics affects organisms and the symbiotic relations between them. A convenient object to study relationships between parasites and their hosts is the host-parasite system "Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae)-Gregarina polymorpha (Hammerschmidt, 1838) Stein, 1848 (Eugregarinorida, Gregarinidae)". For this experiment, we took 390 T. molitor larvae and 24 organic compounds. Groups of mealworms, 15 in each, were subjected to those compounds for 10 days. Then, we recorded the vitality of both the larvae of T. molitor and G. polymorpha. To assess how G. polymorpha had affected the hosts' wellbeing, we looked for changes in the larvae's body mass and compared them to the number of gregarines in their intestines. The vitality of the larvae was inhibited by cyclopentanol and 2-naphthol. The intensity of gregarine invasion was reduced by diphenyl ether, benzyl alcohol, catechol, and 3-aminobenzoic acid. No effect on the number of gregarines was produced by 3,4,5-trihydroxybenzoic acid, cyclohexanemethanol, phenol, benzalkonium chloride, maleic anhydride, cyclohexanol, resorcin, benzoic acid, 2-methylfuran, terpinen-4-ol, 1-phenylethylamine, dibutyl phthalate, 3-furancarboxylic acid, 5-methyl furfural, 6-aminohexanoic acid, succinic anhydride, o-xylene, and benzaldehyde. In the infected T. molitor individuals, the mean number of G. polymorpha equaled 45 specimens per host. The groups of smaller mealworms had fewer gregarines. Positive correlation was seen between growth rates of T. molitor larvae and the intensity of invasion by gregarines.

Synthesis, Radiolabeling, and Biodistribution Study of a Novel DOTA-Peptide for Targeting Vascular Endothelial Growth Factor Receptors in the Molecular Imaging of Breast Cancer.

As angiogenesis plays a pivotal role in tumor progression and metastasis, leading to more cancer-related deaths, the angiogenic process can be considered as a target for diagnostic and therapeutic applications. The vascular endothelial growth factor receptor-1 (VEGR-1) and VEGFR-2 have high expression on breast cancer cells and contribute to angiogenesis and tumor development. Thus, early diagnosis through VEGFR-1/2 detection is an excellent strategy that can significantly increase a patient's chance of survival. In this study, the VEGFR1/2-targeting peptide VGB3 was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), using 6-aminohexanoic acid (Ahx) as a spacer to prevent steric hindrance in binding. DOTA-Ahx-VGB3 was radiolabeled with Gallium-68 (68Ga) efficiently. An in vitro cell binding assay was assessed in the 4T1 cell line. The tumor-targeting potential of [68Ga]Ga-DOTA-Ahx-VGB3 was conducted for 4T1 tumor-bearing mice. Consequently, high radiochemical purity [68Ga]Ga-DOTA-Ahx-VGB3 (RCP = 98%) was prepared and stabilized in different buffer systems. Approximately 17% of the radiopeptide was internalized after 2 h incubation and receptor binding as characterized by the IC50 value being about 867 nM. The biodistribution and PET/CT studies revealed that [68Ga]Ga-DOTA-Ahx-VGB3 reached the tumor site and was excreted rapidly by the renal system. These features convey [68Ga]Ga-DOTA-Ahx-VGB3 as a suitable agent for the noninvasive visualization of VEGFR-1/2 expression.

Metabolic engineering combined with site-directed saturated mutations of α-keto acid decarboxylase for efficient production of 6-aminocaproic acid and 1,6-hexamethylenediamine.

6-Aminocaproic acid (6ACA) and 1,6-hexamethylenediamine (HMDA) are key precursors for nylon synthesis, and both are produced using petroleum-based chemical processes. However, the utilization of bio-based raw materials for biological production of monomers is crucial for nylon industry. In this study, we demonstrated that metabolic engineering of Escherichia coli and selected mutations of α-keto acid decarboxylase successfully synthesized 6ACA and HMDA. An artificial iterative cycle from l-lysine to chain-extended α-ketoacids was introduced into Escherichia coli BL21 (DE3). Then, the extended α-ketoacids were decarboxylated and oxidized for 6ACA production. Overexpression of catalase (KatE) combined with the site-directed mutations of α-isopropylmalate synthase (LeuA) contributed synergistic enhancement effect on synthesis of 6ACA, resulting in a 1.3-fold increase in 6ACA titer. Selected mutations in α-keto acid decarboxylase (KivD) improved its specificity and 170.00 ± 5.57 mg/L of 6ACA with a yield of 0.13 mol/mol (6ACA/l-lysine hydrochloride) was achieved by shake flask cultivation of the engineered strain with the KivD# (F381Y/V461I). Meanwhile, the engineered E. coli could accumulate 84.67 ± 4.04 mg/L of HMDA with a yield of 0.08 mol/mol (HMDA/l-lysine hydrochloride) by replacing aldehyde dehydrogenase with bi-aminotransferases. This achievement marks a significant advancement in the biological synthesis of 6-carbon compounds, since the biosynthetic pathways of HMDA are rarely identified.

Antifibrinolytic and Adjunct Hemostatic Agents: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

To derive systematic-review informed, modified Delphi consensus regarding antifibrinolytic and adjunct hemostatic agents in neonates and children supported with extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE consensus conference. A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. Use of antifibrinolytics (epsilon-aminocaproic acid [EACA] or tranexamic acid), recombinant factor VII activated (rFVIIa), or topical hemostatic agents (THAs). Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Eleven references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. One weak recommendation and three consensus statements are presented. Evidence supporting recommendations for administration of antifibrinolytics (EACA or tranexamic acid), rFVIIa, and THAs were sparse and inconclusive. Much work remains to determine effective and safe usage strategies.

Enhancing Selective Antimicrobial and Antibiofilm Activities of Melittin through 6-Aminohexanoic Acid Substitution.

Leucine residues are commonly found in the hydrophobic face of antimicrobial peptides (AMPs) and are crucial for membrane permeabilization, leading to the cell death of invading pathogens. Melittin, which contains four leucine residues, demonstrates broad-spectrum antimicrobial properties but also significant cytotoxicity against mammalian cells. To enhance the cell selectivity of melittin, this study synthesized five analogs by replacing leucine with its structural isomer, 6-aminohexanoic acid. Among these analogs, Mel-LX3 exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Importantly, Mel-LX3 displayed significantly reduced hemolytic and cytotoxic effects compared to melittin. Mechanistic studies, including membrane depolarization, SYTOX green uptake, FACScan analysis, and inner/outer membrane permeation assays, demonstrated that Mel-LX3 effectively permeabilized bacterial membranes similar to melittin. Notably, Mel-LX3 showed robust antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRPA). Furthermore, Mel-LX3 effectively inhibited biofilm formation and eradicated existing biofilms of MDRPA. With its improved selective antimicrobial and antibiofilm activities, Mel-LX3 emerges as a promising candidate for the development of novel antimicrobial agents. We propose that the substitution of leucine with 6-aminohexanoic acid in AMPs represents a significant strategy for combating resistant bacteria.

Protection effect of Dioscoreae Rhizoma against ethanol-induced gastric injury in vitro and in vivo: A phytochemical and pharmacological study

Ethnopharmacological relevanceDioscoreae Rhizoma, a kind of Chinese yam, is a medicinal and edible plant used in China for strengthening the spleen and stomach. However, there is a lack of modern pharmacology studies regarding its anti-gastric injury activity. Aim of the studyThis study aimed to investigate the phytochemical composition of Chinese yam aqueous extract (CYW) and evaluate its gastroprotective effects against ethanol-induced gastric injury in vitro and in vivo. Materials and methodsThe active components of CYW were identified using HPLC-QTOF-MS/MS in combination with the GNPS molecular networking and network pharmacology. In vitro studies were performed in the RAW264.7/GES-1 cell coculture system. In vivo study, mice were treated with CYW (0.31, 0.63, and 3.14 g/kg BW, orally) for 14 days, followed by a single oral dose of ethanol (10 mL/kg BW) to induce gastric injury. The biochemical, inflammation and oxidative stress markers were analyzed using commercial kits. Histopathology was used to assess the degree of gastric injury. Gene and protein expressions were studied using RT-qPCR and western blotting, respectively. ResultsCYW significantly restored the levels of SOD, GPx and CAT, and reduced the MDA content. Further analyses showed that CYW significantly alleviated the gastric oxidative stress by inhibiting the inflammation via decreasing p-NF-κB and p-IκB-α expression levels and inhibiting the generation of IL-6, TNF-α, and IL-1β. At the same time, the fraction remarkably upregulated Bcl-2, downregulated Bax and increased growth factor secretion, thereby prevented gastric mucous cell. Besides, The combination of HPLC-QTOF-MS/MS, GNPS molecular networking analysis, and network pharmacology demonstrated that linoleic acid, 3-acetyl-11-keto-beta-boswellic acid, adenosine, aminocaproic acid, tyramine, DL-tryptophan, cycloleucine, lactulose, melibiose, alpha-beta-trehalose, and sucrose would be the main active compounds of CYW against ethanol-induced gastric injury. ConclusionThis study showed that CYW is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds. It showed efficacy against ethanol-induced gastric injury by inhibiting inflammation, oxidative stress, and apoptosis in the stomach. The results of the current work indicate that Dioscoreae Rhizoma could be utilized as a type of natural resource for production of new medicine and functional foods to prevent and/or ameliorate ethanol-induced gastric injury.

Splenic hematoma and hemoperitoneum in a Thoroughbred racehorse after racing.

To describe the clinical presentation of a Thoroughbred filly with acute hemoperitoneum from a splenic source immediately after racing. A 3-year-old Thoroughbred filly used for racing and that had raced shortly before presentation to the hospital. On presentation, the filly was quiet, alert, and responsive with a heart rate of 76 beats/min, pale mucous membranes, and absent borborygmi. All other physical examination parameters were within normal limits. Abdominal ultrasound was performed and revealed echogenic free abdominal fluid and a splenic hematoma. Abdominocentesis yielded sanguinous fluid with a PCV of 35%. The next day, repeat ultrasound revealed the splenic hematoma with capsular separation. The filly was treated overnight with isotonic crystalloid fluids and aminocaproic acid (40 mg/kg, IV, slow bolus over 30 minutes followed by 20 mg/kg, IV, q 6 h), potassium penicillin (22,000 IU/kg, IV, q 6 h), gentamicin (6.6 mg/kg, IV, q 24 h), and omeprazole (4 mg/kg, PO, q 24 h). The lowest PCV obtained from the filly was 36 hours after presentation. The filly stabilized with medical treatment and was discharged to a farm for further recuperation. There are no published reports detailing hemoperitoneum of splenic origin in Thoroughbreds immediately after racing. Hemoperitoneum of splenic origin is not common in horses, with most cases of hemoperitoneum being secondary to acute trauma, neoplasia, parturition, or postoperative complications. While uncommon, this case raises awareness to another differential for a colicky horse immediately after racing.

Carboxyl-functionalized covalent organic frameworks for the extraction of malachite green and crystal violet in environmental water samples prior to quantification by high-performance liquid chromatography.

In this study, monodisperse, uniform, and spherical covalent organic frameworks (COFs) were synthesized using 1,3,5-tris (4-aminophenyl) benzene and 1,3,5-tricarboxaldehyde benzene at room temperature. Post-modification of 6-aminocaproic acid on the COFs yielded carboxyl-modified COFs (COFs-COOH). The modification enhanced the hydrophilicity and adsorption efficiencies of COFs-COOH for malachite green (MG) and crystal violet (CV). A COFs-COOH-based dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed for the analysis of MG and CV. The method showed a linear range from 10 to 1000ng/mL with detection limits of 1.82 and 0.70ng/mL for MG and CV detection, respectively. The recoveries of MG and CV from water samples collected from fish farms and markets ranged from 91.63% to 107.10% with relative standard deviations below 5%. Reproducibility tests demonstrated that the adsorption efficiencies of COFs-COOH were maintained at above 85.86% over 15 cycles. The study verified the potential of COFs-COOH as sorbents for the enrichment and separation of triphenylmethane dyes from complex samples.

Re-assessment of monoclonal antibodies against diclofenac for their application in the analysis of environmental waters.

The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is an important environmental contaminant occurring in surface waters all over the world, because, after excretion, it is not adequately removed from wastewater in sewage treatment plants. To be able to monitor this pollutant, highly efficient analytical methods are needed, including immunoassays. In a medical research project, monoclonal antibodies against diclofenac and its metabolites had been produced. Based on this monoclonal anti-DCF antibody, a new indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed and applied for environmental samples. The introduction of a spacer between diclofenac and the carrier protein in the coating conjugate led to higher sensitivity. With a test midpoint of 3 μg L-1 and a measurement range of 1-30 μg L-1, the system is not sensitive enough for direct analysis of surface water. However, this assay is quite robust against matrix influences and can be used for wastewater. Without adjustment of the calibration, organic solvents up to 5%, natural organic matter (NOM) up to 10 mg L-1, humic acids up to 2.5 mg L-1, and salt concentrations up to 6 g L-1 NaCl and 75 mg L-1 CaCl2 are tolerated. The antibody is also stable in a pH range from 3 to 12. Cross-reactivity (CR) of 1% or less was determined for the metabolites 4'-hydroxydiclofenac (4'-OH-DCF), 5-hydroxydiclofenac (5-OH-DCF), DCF lactam, and other NSAIDs. Relevant cross-reactivity occurred only with an amide derivative of DCF, 6-aminohexanoic acid (DCF-Ahx), aceclofenac (ACF) and DCF methyl ester (DCF-Me) with 150%, 61% and 44%, respectively. These substances, however, have not been found in samples. Only DCF-acyl glucuronide with a cross-reactivity of 57% is of some relevance. For the first time, photodegradation products were tested for cross-reactivity. With the ELISA based on this antibody, water samples were analysed. In sewage treatment plant effluents, concentrations in the range of 1.9-5.2 μg L-1 were determined directly, with recoveries compared to HPLC-MS/MS averaging 136%. Concentrations in lakes ranged from 3 to 4.4 ng L-1 and were, after pre-concentration, determined with an average recovery of 100%.

Hybrid poly(dopamine/phenosafranin) microparticles as replicas of yeast capsules for the immobilization of myoglobin

Yeast capsules (YCs) were loaded with a photosensitive phenosafranin (PSF) dye through electrostatic force-driven spontaneous deposition and served as templates for synthesizing biocompatible microparticles. Oppositely charged dopamine and PSF were encapsulated and deposited onto the yeast polysaccharide scaffold through ionic complexation. Subsequently, self-oxidative polymerization was carried out in situ, forming YC@(PDPSF) microparticles. To extend an innovative idea for diverse design and multipurpose YC@(PDPSF) applications, we immobilized myoglobin (Mb) on their surface. The multifunctional coating facilitated the immobilization of Mb involved in oxygen (O2) storage utilizing the carbodiimide method with 6-aminocaproic acid (ACA) as a linker. The biological activity of Mb encapsulated in YCs and immobilized on the surface of YC@(PDPSF) microparticles was compared using UV–vis spectrophotometry. The assays showed that the catalytic activity of Mb was sufficiently retained after immobilization. This new YC@(PDPSF)-Mb microparticles will have potential applications in biosensors, particularly for detecting and separating specific analytes and small molecules (e.g. NO, CO). Their unique properties could make them valuable for various biomedical purposes including enzyme assays, chromatography, air pollution control devices, and filtration processes in gas mask filters.

Synergistic effect of amino and hydroxyl bifunctional modified h-BN on interfacial thermal conductivity in polydimethylsiloxane matrix: Simulations and experiments

As a widely used thermal conductive matrix material, the interface problem between polydimethylsiloxane (PDMS) and thermal conductive fillers needs to be solved urgently. The interfacial heat transfer mechanism between PDMS and hexagonal boron nitride (h-BN) modified by different groups was studied by combining density functional theory (DFT) simulation and molecular dynamics (MD) simulation. The bi-functionalization of h-BN was achieved by the environmentally friendly 6-aminocaproic acid (ACA) additive-assisted water ball milling process. The h-BN/PDMS composite thermal interface materials were prepared using a simple rolling method. The thermal conductivity of the obtained sample reached 1.256 W m−1 K−1 at a filler loading of 15 wt%. The proposed bifunctional synergistic heat transfer mechanism is expected to provide theoretical guidance for the preparation of high thermal conductivity and insulating PDMS used in electronic communications.