Kilogram scale facile synthesis and systematic characterization of a Gd-macrochelate as T1-weighted magnetic resonance imaging contrast agent.

To overcome the problems of commercial magnetic resonance imaging (MRI) contrast agents (CAs) (i.e., small molecule Gd chelates), we have proposed a new concept of Gd macrochelates based on the coordination of Gd3+ and macromolecules, e.g., poly(acrylic acid) (PAA). To further decrease the r2/r1 ratio of the reported Gd macrochelates that is an important factor for T1 imaging, in this study, a superior macromolecule hydrolyzed polymaleic anhydride (HPMA) was found to coordinate Gd3+. The synthesis conditions were optimized and the generated Gd-HPMA macrochelate was systematically characterized. The obtained Gd-HPMA29 synthesized in a 100 L of reactor has a r1 value of 16.35 mM-1 s-1 and r2/r1 ratio of 2.05 at 7.0 T, a high Gd yield of 92.7% and a high product weight (1074 g), which demonstrates the feasibility of kilogram scale facile synthesis. After optimization of excipients and sterilization at a high temperature, the obtained Gd-HPMA30 formulation has a pH value of 7.97, osmolality of 691 mOsmol/kg water, density of 1.145 g/mL, and viscosity of 2.2 cP at 20 â„ƒ or 1.8 cP at 37 â„ƒ, which meet all specifications and physicochemical criteria for clinical injections indicating the immense potential for clinical applications.

The effects of PHB-g-MA types on the mechanical, thermal, morphological, structural, and rheological properties of polyhydroxybutyrate biopolymers.

This study investigates the grafting of polyhydroxybutyrate (PHB) chains with maleic anhydride (MA) in concentrations ranging from 5 % to 10 % by weight. This process was conducted during microwave treatment and using a reactive extruder, employing benzoyl peroxide (BPO) as the initiator. The impact of these methods on PHB's overall properties was thoroughly investigated. In the study, PHB-g-MA was incorporated into neat PHB via the extrusion process at a 5 % loading rate. Notably, the mechanical properties exhibited an increase in the presence of PHB-g-MA, likely due to morphological improvements in the neat PHB, as indicated by morphological characterization. X-ray diffraction results indicated crystallinity percentages increase with the addition of MA. Differential scanning calorimetry revealed minimal variation in melting and crystallization temperatures when PHB-g-MA was included. Both storage and loss moduli were enhanced by the incorporation of PHB-g-MA, and the blends exhibited consistent tan delta values. Regarding rheological properties, the storage and loss moduli of PHB blends containing PHB-g-MA blends were observed to rise with rising frequency values. Based on these results, the microwave process was identified as the most effective method for grafting.

N-benzyl-N-methyldecan-1-amine, derived from garlic, and its derivative alleviate 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice.

Given the intricate etiology and pathogenesis of atopic dermatitis (AD), the complete cure of AD remains challenging. This study aimed to investigate if topically applying N-benzyl-N-methyldecan-1-amine (BMDA), derived from garlic, and its derivative [decyl-(4-methoxy-benzyl)-methyl-1-amine] (DMMA) could effectively alleviate AD-like skin lesions in 2,4-dinitrochlorobenzene (DNCB)-treated mice. Administering these compounds to the irritated skin of DNCB-treated mice significantly reduced swelling, rash, and excoriation severity, alongside a corresponding decrease in inflamed epidermis and dermis. Moreover, they inhibited spleen and lymph node enlargement and showed fewer infiltrated mast cells in the epidermis and dermis through toluidine-blue staining. Additionally, they led to a lower IgE titer in mouse sera as determined by ELISA, compared to vehicle treatment. Analyzing skin tissue from the mice revealed decreased transcript levels of inflammatory cytokines (TNF-α, IL-1ß, and IL-6), IL-4, iNOS, and COX-2, compared to control mice. Simultaneously, the compounds impeded the activation of inflammation-related signaling molecules such as JNK, p38 MAPK, and NF-κB in the mouse skin. In summary, these findings suggest that BMDA and DMMA hold the potential to be developed as a novel treatment for healing inflammatory AD.

A sustainable packaging composite of waste paper and poly(butylene succinate-co-lactate) with high biodegradability.

The challenge of global climate change has drawn people's attention to the issue of carbon emissions. Reducing the use of petroleum-derived materials and increasing the use of biodegradable materials is a current focus of research, especially in the packaging materials industry. This study focused on the use of environmentally friendly plastics and waste paper as the main materials for packaging films. Poly(butylene succinate-co-lactate) (PBSL) was modified with maleic anhydride (MA) to form a biobased compatibilizer (MPBSL), which was then blended with a mixture (WPS) of waste-paper powder (WP) and silica aerogel powder (SP) to form the designed composite (MPBSL/WPS). The modification of PBSL with MA improved interfacial adhesion between PBSL and WPS. The structure, thermal, and mechanical properties, water vapor/oxygen barrier, toxicity, freshness, and biodegradability of MPBSL/WPS films were evaluated. Compared with the PBSL/WP film, the MPBSL/WPS film exhibited increased tensile strength at break of 4-13.5 MPa, increased initial decomposition loss at 5 wt% of 14-35 °C, and decreased water/oxygen permeabilities of 18-105 cm3/m2·d·Pa. In the water absorption test, the MPBSL/WPS film displayed about 2-6 % lower water absorption than that of the PBSL/WP film. In the cytocompatibility test, both MPBSL/WPS and PBSL/WP membrane were nontoxic. In addition, compared with PBSL/WP film and the control, the MPBSL/WPS film significantly reduced moisture loss, extended the shelf life, and prevented microbial growth in vegetable and meat preservation tests. Both MPBSL/WPS and PBSL/WP films were biodegradable in a 60-day soil biodegradation test; the degradation rate was 50 % when the WP or WPS content was 40 wt%. Our findings indicate that the composites would be suitable for environmentally sustainable packaging materials.

Establishing efficient toluene elimination over cobalt-manganese bimetallic oxides via constructing strong Co-Mn interaction.

Doping proves to be an efficacious method of establishing intermetallic interactions for enhancing toluene oxidation performance of bimetallic oxides. However, conventional bimetallic oxide catalysts are yet to overcome their inadequacy in establishing intermetallic interactions. In this work, the dispersion of Mn-Co bimetallic sites was improved by hydrolytic co-precipitation, strengthening the intermetallic interactions which improved the structural and physicochemical properties of the catalysts, thus significantly enhancing its catalytic behavior. MnCo-H catalysts fabricated by the hydrolytic co-precipitation method showed promising catalytic performance (T50 = 223 °C, T90 = 229 °C), robust stability (at least 100 h) and impressive water resistance (under 10 vol.% of water) for toluene elimination. Hydrolytic co-precipitation has been found to improve dispersion of MnCo elements and to enhance interaction between Co and Mn ions (Mn4+ + Co2+ = Mn3+ + Co3+), resulting in a lower reduction temperature (215 °C) and a weaker Mn-O bond strength, creating more lattice defects and oxygen vacancies, which are responsible for superior catalytic properties of MnCo-H samples. Furthermore, in situ DRIFTs showed that gaseous toluene molecules adsorbed on the surface of MnCo-H were continuously oxidized to benzyl alcohol → benzaldehyde → benzoate, followed by a ring-opening reaction with surface-activated oxygen to convert to maleic anhydride as the final intermediate, which further generates water and carbon dioxide. It was also revealed that the ring-opening reaction for the conversion of benzoic acid to maleic anhydride is the rate-controlling step. This study reveals that optimizing active sites and improving reactive oxygen species by altering the dispersion of bimetals to enhance bimetallic interactions is an effective strategy for the improvement of catalytic behavior, while the hydrolytic co-precipitation method fits well with this corollary.

Fabrication of maleic anhydride-acrylamide copolymer based sodium alginate hydrogel for elimination of metals ions and dyes contaminants from polluted water.

The study explores the synergy of biobased polymers and hydrogels for water purification. Polymer nanomaterial's, synthesized by combining acrylamide copolymer with maleic anhydride, were integrated into sodium alginate biopolymer using an eco-friendly approach. Crosslinking agents, calcium chloride and glutaraladehyde, facilitated seamless integration, ensuring non-toxicity, high adsorption performance, and controlled capacity. This innovative combination presents a promising solution for clean and healthy water supplies, addressing the critical need for sustainable environmental practices in water purification. In addition, the polymer sodium alginate hydrogel (MAH@AA-P/SA/H) underwent characterization via the use of several analytical procedures, such as FTIR, XPS, SEM, EDX and XRD. Adsorption studies were conducted on metals and dyes in water, and pollutant removal methods were explored. We investigated several variables (such as pH, starting concentration, duration, and absorbent quantity) affect a material's capacity to be adsorbed. Moreover, the maximum adsorption towards Cu2+ is 754 mg/g while for Cr6+ metal ions are 738 mg/g, while the adsorption towards Congo Red and Methylene Blue dye are 685 mg/g and 653 mg/g correspondingly, within 240 min. Adsorption results were further analyzed using kinetic and isothermal models, which showed that MAH@AA-P/SA/H adsorption is governed by a chemisorption process. Hence, the polymer prepared from sodium alginate hydrogel (MAH@AA-P/SA/H) has remarkable properties as a versatile material for the significantly elimination of harmful contaminants from dirty water.

Characterizing graft distribution in maleic anhydride grafted polyethylene - GPC with IR and UV-detection.

As commodity plastics, polyolefins are in high demand and used in innumerable applications. An important reason for their success-story is their high versatility in terms of applications. The application range of polyolefins was significantly extended through the development of functionalization. A common functionalization for improving the compatibility of polyolefins with more polar polymers and surfaces is grafting with maleic anhydride. While maleic anhydride-grafted polyolefins have found widespread application, methods for their characterization remain rudimentary compared to the developments seen in the structural characterization of polyolefins in general. Herein, we propose two new approaches for determining the degree of functionalization as a function of the molar mass of maleic anhydride grafted polyolefins. On the one hand, the latest generation bandpass filter-based IR detectors are shown to be sensitive to the carbonyl moiety of MAH. After optimization of analysis conditions, the relation between MAH content and molar mass could be unraveled in an easily applicable approach suitable for routine analysis. On the other hand, the high reactivity of MAH was leveraged in a tagging approach. By imidization with a UV chromophore, MAH distribution can be assessed by HT-GPC-UV with significantly higher sensitivity compared to HT-GPC-IR.

High-performance and functional fully bio-based polylactic acid/polypropylene carbonate blends by in situ multistep reaction-induced interfacial control.

Using a solvent-free radical grafting technique, glycidyl methacrylate (GMA) and maleic anhydride (MAH) were used as functionalized graft monomers, styrene (St) as a copolymer monomer, and grafted onto polylactic acid (PLA). A series of PLA-g-(GMA/MAH-co-St) graft copolymers were prepared by adjusting the GMA/MAH ratio. Subsequently, the prepared graft copolymers were used as a compatibilizer with PLA and polypropylene carbonate (PPC) for melt blending to prepare PLA/PPC/PLA-g-(GMA/MAH-co-St) blends. The effects of changes in the GMA/MAH ratio in the graft copolymer on the thermodynamics, rheology, optics, degradation performance, mechanical properties, and microstructure of the blend were studied. The results found that GMA, MAH, and St were successfully grafted onto PLA, and the PLA-g-(GMA/MAH-co-St) graft copolymer obtained from the reaction had a good toughening effect on the PLA/PPC blend system, which significantly improved the mechanical properties of the PLA/PPC/PLA-g-(GMA/MAH-co-St) blend without reducing its degradation performance, resulting in a biodegradable blend material with excellent comprehensive performance. In the PLA-g-(GMA/MAH-co-St) grafting reaction system, when GMA/MAH = 1.5/1.5 (w/w), the grafting degree of the graft copolymer increased most significantly, from 0.83 phr to 1.51 phr. This composition of graft copolymer can effectively improve the compatibility between PLA and PPC. The resulting PLA/PPC blend can maintain good melt flow properties (MFR of 14.51 g/10 min), high transparency, and low haze (light transmittance of 91.56 %, haze of 20.5 %), while significantly improving its thermal stability (T95%, Tmax, and Et increased by 12.87 °C, 20.33 °C, and 32.00 kJ/mol, respectively). Moreover, when introducing PLA-g-(GMA/MAH-co-St) (GMA/MAH = 1.5/1.5 (wt/wt)) graft copolymer into the system, the toughness of the PLA/PPC/PLA-g-(GMA/MAH-co-St) blend system is optimal, with the notch impact strength and fracture elongation increasing to 184.6 % and 535.4 % of the PLA/PPC blend, respectively, at which point the fracture surface of the impact sample shows a wrinkled fracture feature indicative of toughness.

Conformational Changes of Poly(Maleic Anhydride-alt-styrene) Modified with Amino Acids in an Aqueous Medium and Their Effect on Cytocompatibility and Hemolytic Response.

The conformational changes of poly(maleic anhydride-alt-styrene) (PSMA) modified with different amino acids (PSMA-Aa) were studied in an aqueous medium as a function of ionic strength and pH. The specific viscosity of PSMA-Aa decreased with increasing salt concentration due to a more compact conformation. There was a decrease in surface tension with increasing concentrations of the modified polyelectrolyte having a greater effect for the PSMA modified with l-phenylalanine at pH 7.0, demonstrating a greater surface-active character. The conformational changes were also confirmed by molecular dynamics studies, indicating that PSMA-Aa exhibits a compact structure at pH 4.0 and a more extended structure at pH 7.0. On the other hand, the conformational changes of PSMA-Aa were related to its biological response, where the higher surface-active character of the PSMA modified with l-phenylalanine correlates very well with the higher hemolytic activity observed in red blood cells, in which the surface-active capacity supports lytic potency in erythrocytes. The cytocompatibility assays indicated that there were no significant cytotoxic effects of the PSMA-Aa. Additionally, in solvent-accessible surface area studies, it was shown that the carboxylate groups of the PSMA modified with l-phenylalanine are more exposed to the solvent at pH 7.0 and high salt concentrations, which correlates with lower fluorescence intensity, reflecting a loss of mitochondrial membrane potential. It is concluded that the study of the conformational changes in PE modified with amino acids is essential for their use as biomaterials and relevant to understanding the possible effects of PE modified with amino acids in biological systems.

Self-Cross-Linkable Maleic Anhydride Terpolymer Coating with Inherent High Antimicrobial Activity and Low Cytotoxicity.

Developing coating materials with low cytotoxicity and high antimicrobial activity has been recognized as an effective way to prevent medical device-associated infections. In this study, a maleic anhydride terpolymer (PPTM) is synthesized and covalently attached to silicone rubber (SR) surface. The formed coating can be further cross-linked (SPM) through the self-condensation of pendent siloxane groups of terpolymer. No crack or delamination of SPM was observed after 500 cycles of bending and 7 day immersion in deionized water. The sliding friction force of a catheter was reduced by 50% after coating with SPM. The SPM coating without adding any extra antibacterial reagents can kill 99.99% of Staphylococcus aureus and Escherichia coli and also significantly reduce bacterial coverage, while the coating displayed no antimicrobial activity when maleic anhydride groups of SPM were aminated or hydrolyzed. The results of the repeated disinfection tests showed that the SR coated with SPM could maintain 87.3% bactericidal activity within 5 cycles. Furthermore, the SPM coating only imparted slight toxic effect (>85% viability) on L929 cells after 36 h of coculture, which is superior to the coating of aminated SPM conjugated with the antimicrobial peptide E6. The terpolymer containing maleic anhydride units have great potential as a flexible and durable coating against implant infections.

Toward the Improvement of Maleic Anhydride Functionalization in Polyhydroxybutyrate (PHB): Effect of Styrene Monomer and Sn(Oct)2 Catalyst.

In this work, polyhydroxybutyrate (PHB) was maleic anhydride (MA)-grafted in the molten state, using dicumyl peroxide (DCP) as a reaction initiator. Tin(II) 2-ethylhexanoate (Sn(Oct)2) and styrene monomer (St.) were used to maximize the maleic anhydride grafting degree. When PHB was modified with MA/DCP and MA/DCP/Sn(Oct)2, viscosity was reduced, suggesting chain scission in relation to pure PHB. However, when the styrene monomer was added, the viscosity increased due to multiple grafts of MA and styrene into the PHB chain. In addition, the FTIR showed the formation of a new band at 1780 cm-1 and 704 cm-1, suggesting a multiphase copolymer PHB-g-(St-co-MA). The PHB (MA/DCP) system showed a grafting degree of 0.23%; however, the value increased to 0.39% with incorporating Sn(Oct)2. The highest grafting efficiency was for the PHB (MA/DCP/St.) system with a value of 0.91%, while the PHB (MA/DCP/St./Sn(Oct)2) hybrid mixture was reduced to 0.73%. The chemical modification process of PHB with maleic anhydride increased the thermal stability by about 20 °C compared with pure PHB. The incorporation of 0.5 phr of the Sn(Oct)2 catalyst increased the efficiency of the grafting degree in the PHB. However, the St./Sn(Oct)2 hybrid mixture caused a deleterious effect on the maleic anhydride grafting degree.

Boiling water resistant fully bio-based adhesive made from maleated chitosan and glucose with excellent performance.

Biomass resources are widely considered potential alternatives to formaldehyde-based wood adhesives because of their abundance. In this study, an environmentally friendly biomass adhesive, carboxylated chitosan-glucose (CSC-G), was prepared using chitosan, maleic anhydride, and glucose. The structure and water resistance of the adhesive were analyzed in detail. Maleic anhydride act as a bridge connecting chitosan and glucose, giving the adhesive good water solubility and resistance. The improved water resistance of the CSC-G adhesive was attributed to the formation of covalent cross-linked structures and an increased degree of system cross-linking. Additionally, the curing temperature of the CSC-G adhesive was superior to those of previously reported polyester adhesives. This study not only expands the application scope of fishery waste, but also demonstrates its great potential for the preparation of high-performance plywood.

Batch culture analysis to identify potent organic acids for suppressing ruminal methane production.

We performed an in vitro rumen batch culture study to screen 11 commercially available organic acids for methane-suppressing ability and analyzed the rumen microbiota to determine the mode of action of the acids that showed potent methane-suppressing activity. Nine of the 11 acids showed methane-suppressing activity. Maleic anhydride, itaconate, citrate, and fumarate, which showed the highest activity, were further examined. These four acids showed methane-suppressing activity irrespective of the hay-to-concentrate ratios of the substrate. Maleic anhydride and itaconate decreased total gas and short-chain fatty acid production. Maleic anhydride and fumarate increased propionate production, while itaconate increased butyrate production. Maleic anhydride, itaconate, and citrate increased lactate production. Fumarate increased the abundance of bacteria involved in propionate production. Maleic anhydride, itaconate, and citrate increased the abundance of bacteria involved in lactate production. Thus, the results indicate that maleic anhydride, itaconate, and citrate may decrease methane in part by stimulating the acrylate pathway.

Mechanism of the Photochemical Isomerization and Oxidation of 2-Butenedial: A Theoretical Study.

Under tropospheric conditions, 2-butenedial is photochemically removed to produce secondary organic aerosol. Upon solar irradiation in the lower troposphere, the main photochemical products are ketene-enol (a key intermediate product), furanones, and maleic anhydride. The oxidative reaction mechanism was studied using the multireference method CASSCF to explore the hypersurface of the two most accessible singlet excited states, and by DFT for the ground state. Photoisomerization of 2-butenedial in the first excited state directly produces ground state ketene-enol upon nonradiative relaxation. From this intermediate, furan-2-ol and successively 3H-furan-2-one and 5H-furan-2-one are formed. The cooperative effect of two water molecules is essential to catalyze the cyclization of ketene-enol to furan-2-ol, followed by hydrogen transfers to furanones. Two water molecules are also necessary to form maleic anhydride from furan-2-ol. For this last reaction, in which one extra oxygen must be acquired, we hypothesize a mechanism with singlet oxygen as the oxidant.

Highly efficient removal of Pb2+ from wastewater by a maleic anhydride modified organic porous adsorbent.

Sorption is prominent in low price, high efficiency, availability, and eco-friendliness. Organic porous materials have the characteristics of easy functionalization, diverse structure and stability, and show great potential in adsorption, energy storage, catalysis, and other fields. A mesoporous phenolic resin-type polymer (PRP) was successfully synthesized and modified by solid state reaction with maleic anhydride to prepare adsorbent (called as PRP-MAH) for sorption of Pb2+. The impact of reaction conditions (the pH value, reaction temperature, fresh concentration of solution, ionic strength and reaction time, etc.) was systematically studied. Characterization methods such as SEM, FTIR, and XPS indicated that the synthesized adsorbent PRP-MAH had regular morphology and good stability. The fitting of isothermal adsorption experiment data conforms to Langmuir sorption isotherm, and the sorption capacity reached 366.40 mg·g-1 at 308 K. The kinetic data were consistent with the quasi-second-order model, which indicated that the chemisorption might play the main role in the sorption process. Thermodynamic research manifested that the sorption of Pb2+ by PRP-MAH was carried out by a spontaneous process at the study temperature. The studies show that PRP-MAH can remove Pb2+ from water solution through ion exchange, electrostatic attraction, and surface complexation.

Maleic anhydride promotes humus formation via inducing functional enzymes response in composting.

The purpose of this paper was to explore the promotion of maleic anhydride on the polymerization of precursors into humus in composting, and analyze the changes of key functional enzymes. The results showed that the content of humus in the treatment group added maleic anhydride (MAH) was higher than that in the control check (CK). The decrease rate of humus precursor concentration of MAH was also higher than that of CK. In MAH, the activities of laccase and tyrosinase were improved, thus enhanced the catalytic conversion of humus precursors. The analysis of bacterial community showed that maleic anhydride optimized the community structure of humification functional enzymes producing bacteria, with the most obvious increase of Firmicutes. In conclusion, this study provided theoretical supports for the introduction of maleic anhydride into the compost system to promote the polymerization of precursors to form humus.

Versatile Diphosphine Chelators for Radiolabeling Peptides with 99mTc and 64Cu.

We have developed a diphosphine (DP) platform for radiolabeling peptides with 99mTc and 64Cu for molecular SPECT and PET imaging, respectively. Two diphosphines, 2,3-bis(diphenylphosphino)maleic anhydride (DPPh) and 2,3-bis(di-p-tolylphosphino)maleic anhydride (DPTol), were each reacted with a Prostate Specific Membrane Antigen-targeted dipeptide (PSMAt) to yield the bioconjugates DPPh-PSMAt and DPTol-PSMAt, as well as an integrin-targeted cyclic peptide, RGD, to yield the bioconjugates DPPh-RGD and DPTol-RGD. Each of these DP-PSMAt conjugates formed geometric cis/trans-[MO2(DPX-PSMAt)2]+ (M = 99mTc, 99gTc, natRe; X = Ph, Tol) complexes when reacted with [MO2]+ motifs. Furthermore, both DPPh-PSMAt and DPTol-PSMAt could be formulated into kits containing reducing agent and buffer components, enabling preparation of the new radiotracers cis/trans-[99mTcO2(DPPh-PSMAt)2]+ and cis/trans-[99mTcO2(DPTol-PSMAt)2]+ from aqueous 99mTcO4- in 81% and 88% radiochemical yield (RCY), respectively, in 5 min at 100 °C. The consistently higher RCYs observed for cis/trans-[99mTcO2(DPTol-PSMAt)2]+ are attributed to the increased reactivity of DPTol-PSMAt over DPPh-PSMAt. Both cis/trans-[99mTcO2(DPPh-PSMAt)2]+ and cis/trans-[99mTcO2(DPTol-PSMAt)2]+ exhibited high metabolic stability, and in vivo SPECT imaging in healthy mice revealed that both new radiotracers cleared rapidly from circulation, via a renal pathway. These new diphosphine bioconjugates also furnished [64Cu(DPX-PSMAt)2]+ (X = Ph, Tol) complexes rapidly, in a high RCY (>95%), under mild conditions. In summary, the new DP platform is versatile: it enables straightforward functionalization of targeting peptides with a diphosphine chelator, and the resulting bioconjugates can be simply radiolabeled with both the SPECT and PET radionuclides, 99mTc and 64Cu, in high RCYs. Furthermore, the DP platform is amenable to derivatization to either increase the chelator reactivity with metallic radioisotopes or, alternatively, modify the radiotracer hydrophilicity. Functionalized diphosphine chelators thus have the potential to provide access to new molecular radiotracers for receptor-targeted imaging.

Designing a novel poly (methyl vinyl ether maleic anhydride) based polymeric membrane with enhanced antifouling performance for removal of pentachlorophenol from aqueous solution.

In this current study, poly (methyl vinyl ether maleic anhydride) (PMVEAMA), a sustainable additive, was incorporated into poly (ether-ether sulfone) (PEES) polymer to design a novel polymeric hybrid membrane for the efficient filtration of toxic pentachlorophenol (PCP) from an aqueous medium. Hydrophilic additives significantly altered the membrane's morphology, structure, porosity, water content, and flux performance compared to the bare PEES membrane. The influence of PMVEAMA on the structural modification of the synthesized polymer membrane was confirmed by SEM, ATR-FTIR, XRD, AFM, zeta potential and contact angle. Findings revealed that the addition of PMVEAMA to the PEES polymer enhances the porosity (17.7%-28.9%), water content (29.8%-39.8%), and pure water flux (186 Lm-2h-1 to 349 Lm-2h-1). The effect of PMVEAMA concentration on the PEES membrane exhibited more finger like pores, better porosity and hydrophilicity, reduced surface roughness, fouling and increased permeability. The fouling studies exhibit an improved 57% PCP rejection and permeation flux of 22.3 Lm-2h-1 due to the addition of the hydrophilic additive. Surprisingly, the incorporation of PMVEAMA into the bare PEES membrane resulted in a high flux recovery ratio of 73.7%. The antifouling properties and enhanced permeability of the PEES/PMVEAMA membrane indicates its potential application in water purification sectors for the efficient separation of contaminants.

Multi Stimuli-Responsive Aggregation-Induced Emission Active Polymer Platform Based on Tetraphenylethylene-Appended Maleic Anhydride Terpolymers.

Multi stimuli-responsive aggregation-induced emission (AIE) active polymers have great application prospects in high-tech innovations. Herein, three types of tetraphenylethylene (TPE)-containing monomers were synthesized and utilized in preparing TPE-appended maleic anhydride terpolymers. After hydrolysis, the produced TPE-appended maleic acid terpolymers have identical linear charge densities but different "primary" structures, which created widely varied microenvironments around the carboxylate and TPE groups. Benefiting from the synergistic interaction of the TPE moiety and the terpolymer conformation change, the TPE-appended maleic acid terpolymers exhibited fluorescence changes in response to multi stimuli, including pH, ionic strength, Ca2+, and bovine serum albumin. On both the "signaling" and the "stimuli acceptor" sides, the multi stimuli-responsive fluorescence behavior was influenced markedly by the terpolymer primary structure. The fundamental insights gained in the present work are important for developing an efficient and versatile stimuli-responsive AIE-active polymer platform for chemo-sensing, bioimaging, and so on.

A new selective inhibitor for IMP-1 metallo-ß-lactamase, 3Z,5E-octa-3,5-diene-1,3,4-tricarboxylic acid-3,4-anhydride.

3Z,5E-Octa-3,5-diene-1,3,4-tricarboxylic acid-3,4-anhydride (ODTAA, 1) was isolated from Paecilomyces sp. FKI-6801 for its selective IMP-1 MBL inhibitory activity. The first total synthesis of 1 from the commercially available compound was achieved in 9 steps with 28% overall yield. Introduction of catechol to the maleic anhydride of 1 improved the IC50 toward IMP-1 MBL and the inhibitory activity against IMP-1 MBL-producing P. aeruginosa. Treatment of the maleic anhydride scaffold with amine showed that the ß-carbonyl-α,ß-unsaturated carboxylic acid moiety is required as a pharmacophore for IMP-1 MBL inhibition.