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Biodegradable electronic devices play a crucial role in addressing the escalating issue of electronic waste accumulation, which poses significant environmental threats. In this study, we explore the utilization of a methanol-based extract of the Elaeodendron buchananii plant blended with a carboxymethyl cellulose biopolymer to produce a biodegradable and environmentally friendly functional material for a resistive switching memory system using silver and tungsten electrodes. Our analyses revealed that these two materials chemically interact to generate a perfect composite with near semiconducting optical bandgap (4.01 eV). The resultant device exhibits O-type memory behavior, with a low ON/OFF ratio, strong endurance (≥103 write/erase cycles), and satisfactory (≥103) data retention. Furthermore, through a comprehensive transport mechanism analysis, we observed the formation of traps in the composite that significantly improved conduction in the device. In addition, we established that altering the voltage amplitude modifies the concentration of traps, leading to voltage amplitude-driven multiple resistance states. Overall, our findings underscore the potential of functionalizing polymers that can be functionalized by incorporating plant extracts, resulting in biodegradable and nonvolatile memory devices with promising performance metrics.

Gamma-aminobutyric acid (GABA) signaling is the principal inhibitory pathway in the central nervous system. It is critical in neuronal cell proliferation and fate determination. Any aberration in GABA inhibition results in psychiatric and neurological diseases. Thus, modulating GABAergic neurotransmission has become the basis of drug therapy for psychiatric and several neurological diseases. Though GABA and muscimol are classical inhibitors of GABA receptors, the search for novel inhibitors continues unabated. In this study, the binding mechanism of GABA and muscimol was elucidated and applied in the search for small molecule GABAergic inhibitors using comprehensive computational techniques. It was revealed that a high-affinity binding of GABA and muscimol was mediated by a water molecule involving α 1 Thr129 and then stabilized by strong interactions including salt bridges with β 2 Glu155 and α 1 Arg66 amidst hydrogen bonds, π-π stacking, and π -cation interactions with other residues. The binding of GABA and muscimol was also characterized by stability and deeper penetration into the hydrophobic core of the protein which resulted in conformational changes of the binding pocket and domain, by inducing correlated motions of the residues. Thermodynamics analysis showed GABA and muscimol exhibited total binding free energies of -19.85 ± 8.83 Kcal/mol and -26.55 ± 3.42 Kcal/mol, respectively. A pharmacophore model search, based on the energy contributions of implicating binding residues, resulted in the identification of ZINC68604167, ZINC19735138, ZINC04202466, ZINC00901626, and ZINC01532854 as potential GABA-mimetic compounds from metabolites and natural products libraries. This study has elucidated the binding mechanisms of GABA and muscimol and successfully applied in the identification of GABA-mimetic compounds.Communicated by Ramaswamy H. Sarma.

The preparation, characterization, and photocatalytic application of tungsten or molybdenum carbides (Ni-WC, 1 , Co-WC, 2 , Ni-MoC, 3 , Co-MoC, 4 , NiCo-WC, 5 , NiCo-MoC, 6 , NiFe-WC, 7 , and NiFe-MoC, 8 ) doped with transition metals (Fe, Co, and Ni) are reported. These transition-metal carbide (TMC) particles show that the submicrometer globular particles agglomerated to form larger particles, with smaller crystallites present on the surface of the large particles. These crystallite sizes range between 4 and 34 nm (as calculated from X-ray diffraction data) depending on the metal dopant and type of carbide. Oxidation of the metal carbides is evident from the two sets of photoelectron lines present in the X-ray photoelectron spectroscopy (XPS) of the W 4f area. The Mo 3d spectra reveal four sets of photoelectron lines associated with oxidized MoO 2 and MoO 3 as well as Mo 2+ and Mo 3+ associated with MoC 1- x . The XPS of the dopant metals Ni, Co, and Fe also show partial oxidation. The photocatalytic decomposition of Congo red (an azo dye) is used as a model reaction to determine the photocatalytic activities of the transition-metal carbides, which is related to the TMCs' optical band gap energies., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Zeolitic imidazolate frameworks (ZIFs), such as ZIF-8 and ZIF-67, were found to be efficient catalysts. However, ZIFs are not used much in photocatalysis due to their low photocatalytic activity for most reactions. The photocatalytic activity can be improved by modifying the framework by exchanging the Zn(II) ions (ZIF-8) and Co(II) ions (ZIF-67) with a more photocatalytically active metal(II) ion to form an efficient bimetallic ZIF photocatalyst. Redox-active iron (Fe)-based materials are known to be highly potent photocatalysts. Thus, incorporating iron into ZIFs could significantly enhance their photocatalytic performance. In this study, we modified nanosized ZIF-8(Zn) and ZIF-67(Co) via metal (Fe 2+ ) exchange to produce bimetallic frameworks that are photocatalytically more active than their parent ZIFs. Nanosized ZIF-8 and ZIF-67 were synthesized isothermally in either water or methanol under ambient conditions. From these, Fe-containing bimetallic ZIF-8 and ZIF-67 nanoparticles were synthesized via the metal exchange, and their performance on the photocatalytic degradation of dye was evaluated. The morphology and crystal structures of the pristine ZIF-8 and ZIF-67 nanoparticles were retained to a large extent during the iron exchange. Their Brunauer-Emmett-Teller (BET) surface areas decreased by less than 15% for nZIF-8 and less than 12% for nZIF-67. The binding energy values on X-ray photoelectron spectroscopy (XPS) confirmed the preservation of the oxidation state of Fe(II) during the exchange process. A remarkably higher catalytic activity was observed for the photocatalytic degradation of dye by the Fe-exchanged nZIF-8 and nZIF-67 compared to their parent ZIFs. This proved that the incorporation of Fe(II) centers into the ZIF framework enhanced the photocatalytic activity of the framework dramatically. In addition, these catalysts can be regenerated and reused without an appreciable loss in activity., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

According to UV-vis spectroscopy (0.10 mM, CH 2 Cl 2 at 25 °C), the catalyst transformation (which could possibly include ligand dissociation with active catalyst formation, dimer formation, and decomposition) rate constants ( k obs ) of Grubbs' first ( 1 ) and second ( 2 ) generation catalysts are 7.48 × 10 -5 and 1.52 × 10 -4 s -1 , respectively. From 31 P NMR (0.1 M, CD 2 Cl 2 , at 25 °C), the catalyst transformation was 5.1% for 1 and 16.5% for 2 after 72 h. However, due to the larger concentrations of the NMR samples compared to the UV-vis samples, the extent of transformation did not correspond. The oxidation potential of the Ru II /Ru III couple of 2 ( E °' = 27.5 mV at v = 200 mV s -1 ) was considerably lower than that of 1 ( E °' = 167 mV at v = 200 mV s -1 ). In the case of 1 , a second reduction peak appeared at slow scan rates. This may probably be ascribed to an electrochemically active compound that was formed from the intermediate cation 1 •+ and the subsequent reduction of the latter. The oxidation/reduction of 1 proceeds according to an E r C i electrochemical mechanism (E r = electrochemically reversible step, C i = chemically irreversible step), whereas 2 proceeds according to an E r C r electrochemical mechanism (E r = electrochemically reversible step, C i = chemically reversible step)., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Treatment of hydroxylated silica nanopowders S1 and allyl-functionalized silica nanopowders S2 with 3-(diphenylborano)- or 3-bis(pentafluorophenylborano)propyltrimethoxysilane or 2-(diphenylphosphino)- or 2-(dicyclohexylphosphino)ethyltriethoxysilane generates silica nanopowder supported Lewis acids S3 and silica nanopowder supported Lewis bases S4 . These surfaces were characterized by 13 C, 11 B, and 31 P cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR), X-ray photoelectron spectroscopy (XPS), and attenuated total reflection Fourier transform infrared (ATR FTIR). When S3 is combined with solution-phase Lewis bases PR 3 (R = C 6 F 5 , C 6 H 5 , mesityl), six associated silica nanopowder supported frustrated Lewis pairs (FLPs) are formed. In another set of six reactions, the interactions between the supported Lewis bases S4 and solution-phase Lewis acids BR 3 with R = C 6 F 5 , C 6 H 5 , mesityl produced six more associated supported FLPs. The capture of CO 2 by these FLPs producing FLP-CO 2 Lewis pair adducts S5 and S6 were highlighted by ATR FTIR, and it was found that FLP S5e with R = C 6 H 5 on both the supported Lewis acid and solution-phase Lewis base trapped the largest quantities of CO 2 on the silica nanopowder supports. Conversion of CO 2 to HCOOH was achieved by first activating H 2 to generate activated FLP-H 2 surfaces S7 and S9 . Addition of CO 2 then generated HCOOH via the silica nanopowder supported FLP-HCOOH adducts S8 and S10 . Qualitative identification of HCOOH generation was achieved by ATR FTIR measurements, and surface 10b with R = C 6 H 5 proved to be the most successful silica nanopowder surface bound FLP in HCOOH generation. In some cases, diborano formates (-BO(CH)OB-) S11 and S12 were also identified as side products during HCOOH formation. Spectroscopic characterization of purposefully synthesized S11 and S12 included 11 B and 31 P CP MAS NMR.

In order to better understand intramolecular communication between molecular fragments, a series of ferrocene-functionalized β-diketonato manganese(III) complexes, [Mn(FcCOCHCOR) 3 ] with R = CF 3 , 1, CH 3 , 2, Ph = C 6 H 5 , 3, and Fc = Fe II (η 5 -C 5 H 4 )(η 5 -C 5 H 5 ), 4, the mixed ligand β-diketonato complex [Mn(FcCOCHCOFc) 2 (FcCOCHCOCH 3 )], 5, as well as the acac complex [Mn(CH 3 COCHCOCH 3 ) 3 ], 6, were subjected to an electrochemical and X-ray photoelectron spectroscopy (XPS) study. The ferrocenyl (Fe II ) and Mn III redox potentials, E°', and photoelectron lines were sufficiently resolved in each complex to demonstrate a linear correlation between E°' and group electronegativities of ligand R groups, χ R , or Σχ R , as well as with binding energies of both the Fe 2p 3/2 and Mn 2p 3/2 photoelectron lines. These relationships are consistent with effective communication between molecular fragments of 1-5. From these relationships, prediction of Mn and Fe core electron binding energies in [Mn(R 1 COCHCOR 2 ) 3 ] complexes from known manganese and/or ferrocenyl redox potentials are, therefore, now possible. Ligand infrared carbonyl stretching frequencies were successfully related to binding energy as a measure of the energy required for inner-sphere reorganization. In particular it became possible to explain why, upon electrochemical oxidation or photoionization, the ferrocenyl Fe II inner-shell of 1-5 needs more energy in complexes with ligands bearing electron-withdrawing (CF 3 ) groups than in ligands bearing electron-donating groups such as ferrocenyl. The XPS determined entity I ratio (the ratio between the intensities of the satellite and main metal 2p 3/2 photoelectron lines) is an indication not only of the amount of charge transferred, but also of the degree of inner-sphere reorganization. Just as for binding energy, the quantity I ratio was also found to be related to the energy requirements for the inner-sphere reorganization depicted by the vibrational frequency, v co .

Objective: To evaluate a model of care to improve arthritis detection and treatment in an urban Aboriginal population., Design: Cohort study., Setting: The Elbow River Healing Lodge in Calgary, Alta., Participants: A total of 26 participants with noninflammatory arthritis and 12 with inflammatory arthritis., Intervention: A monthly rheumatology clinic was embedded in the primary health care service and received referrals from primary care providers and allied health care professionals, or self-referrals. All participants had a standardized assessment to determine their diagnosis. Those with noninflammatory musculoskeletal conditions were returned to primary care management and those with inflammatory arthritis conditions were followed by the rheumatologist., Main Outcome Measures: Accessibility, acceptability, effectiveness, and cultural safety were evaluated as measures of quality for the model of care., Results: Nearly all participants (87%) thought the services were very easy or easy to obtain, and overall satisfaction with the model of care was high (89% were very satisfied or satisfied). For inflammatory arthritis patients, the swollen and tender joint counts improved over time (both P < .01) and patient safety was assured. A high degree of cultural safety was provided, with 95% of participants responding that they did not perceive discrimination on the basis of race., Conclusion: This model of care facilitated access for diagnosis and return to care of inflammatory arthritis conditions, and was acceptable to participants. This model of care removes the complexities of access to non-family physician specialty care while providing health care in a setting valued by Aboriginal patients., (Copyright© the College of Family Physicians of Canada.)

A series of ferrocenyl-functionalized β-diketonato manganese(III) complexes, [Mn(FcCOCHCOR)₃] with R = CF₃, CH₃, Ph (phenyl) and Fc (ferrocenyl) was subjected to a systematic XPS study of the Mn 2p 3/2 and Fe 2p 3/2 core-level photoelectron lines and their satellite structures. A charge-transfer process from the β-diketonato ligand to the Mn(III) metal center is responsible for the prominent shake-up satellite peaks of the Mn 2p photoelectron lines and the shake-down satellite peaks of the Fe 2p photoelectron lines. Multiplet splitting simulations of the photoelectron lines of the Mn(III) center of [Mn(FcCOCHCOR)₃] resemble the calculated Mn 2p 3/2 envelope of Mn 3+ ions well, indicating the Mn(III) centers are in the high spin state. XPS spectra of complexes with unsymmetrical β-diketonato ligands (i.e., R not Fc) were described with two sets of multiplet splitting peaks representing fac and the more stable mer isomers respectively. Stronger electron-donating ligands stabilize fac more than mer isomers. The sum of group electronegativities, Σχ R , of the β-diketonato pendant side groups influences the binding energies of the multiplet splitting and charge transfer peaks in both Mn and Fe 2p 3/2 photoelectron lines, the ratio of satellite to main peak intensities, and the degree of covalence of the Mn-O bond.

Reaction of [Mn3(OAc)6O·3H2O](+) (1) with ferrocenyl β-diketones of the type FcCOCH2COR with R = CF3 (2a) and CH3 (2b), Ph = C6H5 (2c), and Fc = Fe(II)(η(5)-C5H4)(η(5)-C5H5) (2d) yielded a series of ferrocene-functionalized β-diketonato manganese(III) complexes 3a-3d, respectively, of general formula [Mn(FcCOCHCOR)3]. The mixed-ligand β-diketonato complex [Mn(FcCOCHCOFc)2(FcCOCHCOCH3)] (4) was obtained by reacting mixtures of diketones 2b and 2d with 1. A single-crystal X-ray structure determination of 3b (Z = 2, triclinic, space group P1̅) highlighted a weak axial elongating Jahn-Teller effect and a high degree of bond conjugation. An X-ray photoelectron spectroscopic study, by virtue of linear relationships between group electronegativities of ligand R groups, χR, or ∑χR, and binding energies of both the Fe 2p3/2 and Mn 2p3/2 photoelectron lines, confirmed communication between molecular fragments of 2a-2d as well as 3a-3d. This unprecedented observation allows prediction of binding energies from known β-diketonato side group χR values.

Nonperipherally hexyl-substituted metal-free tetrabenzoporphyrin (2H-TBP, 1a) tetrabenzomonoazaporphyrin (2H-TBMAP, 2a), tetrabenzo-cis-diazaporphyrin (2H-TBDAP, 3a), tetrabenzotriazaporphyrin (2H-TBTAP, 4a), and phthalocyanine (2H-Pc, 5a), as well as their copper complexes (1b-5b), were synthesized. As the number of meso nitrogen atoms increases from zero to four, λmax of the Q-band absorption peak becomes red-shifted by almost 100 nm, and extinction coefficients increased at least threefold. Simultaneously the blue-shifted Soret (UV) band substantially decreased in intensity. These changes were related to the relative electron-density of each macrocycle expressed as the group electronegativity sum of all meso N and CH atom groups, ∑χR. X-ray photoelectron spectroscopy differentiated between the three different types of macrocyclic nitrogen atoms (the Ninner, (NH)inner, and Nmeso) in the metal-free complexes. Binding energies of the Nmeso and Ninner,Cu atoms in copper chelates could not be resolved. Copper insertion lowered especially the cathodic redox potentials, while all four observed redox processes occurred at larger potentials as the number of meso nitrogens increased. Computational chemical methods using density functional theory confirmed 1b to exhibit a Cu(II) reduction prior to ring-based reductions, while for 2b, Cu(II) reduction is the first reductive step only if the nonperipheral substituents are hydrogen. When they are methyl groups, it is the second reduction process; when they are ethyl, propyl, or hexyl, it becomes the third reductive process. Spectro-electrochemical measurements showed redox processes were associated with a substantial change in intensity of at least two main absorbances (the Q and Soret bands) in the UV spectra of these compounds.

The bimetallic paddlewheel catalyst precursor, [Pd(II)Co(II)(μ-OOCCH(3))(4)] H(2)O·2CH(3)COOH (1), prepared from [Pd(3)(μ-OOCCH(3))(6)] and [Co(OOCCH(3))(2)], was used as a single source precursor to prepare, after binding to a surface-hydroxylated silicon wafer and oxidation, the bimetallic oxides of Pd(IV)Co(III)/SiO(2) catalyst supported on a model planar (i.e., two-dimensional) silicon wafer. This catalyst catalyzes the aerobic oxidation of alcohols to its corresponding carbonyl compounds. The bimetallic tetracarboxylato catalyst precursor was bonded to the surface-hydroxylated silicon wafer by spin-coating and also by grafting. X-ray photoelectron spectroscopy (XPS) revealed that one of the four μ-acetato bridging ligands was substituted by Si-O fragments in a covalent bond formation process during grafting of 1 onto the wafer. In contrast, during the spin-coating process, all four acetato ligands remained intact during fixation on the silicon surface. Upon oxidation and workup, the grafted sample's Pd:Co ratio remained unchanged (1.0:1.3), whereas the spin-coated sample's Pd content decreased with respect to Co content. XPS determined binding energies were interpreted to imply that after oxidation in an oxygen/argon mixture of the grafted sample both Pd(II) and Co(II) were oxidized to produce PdO(2) (337.5 eV) and Co(III)(2)O(3) (781.1 eV) which most probably interacts with the silicon surface via Pd(IV)-O-Si and Co(III)-O-Si bonds. Solvent free aerobic oxidation of octadecanol to its corresponding carbonyl compound was achieved on this oxidized Pd(IV)Co(III)/SiO(2) model catalyst using molecular oxygen as oxidant under solvent-free conditions. The use of the single source catalyst precursor, 1, resulted in a Pd(IV)Co(III)/SiO(2) catalyst with superior catalytic activity toward the oxidation of octadecanol over a catalyst prepared from a physical mixture of the separate reactant compounds tripalladium(II) hexaacetate and cobalt(II) diacetate.

Background: Gold(I) and platinum(II) d(10) and d(8) electronic complexes such as (Au(PPh(2)CH(2)CH(2)PPh(2))(2))Cl and cisplatin, ((H(3)N)(2)PtCl(2)), possess strong antineoplastic activities. Almost no information is available regarding the anticancer activity of isoelectronic silver(I) d(10) complexes. This study examined the cytotoxicity of stable water-soluble silver(I) carboxylates. The results were related to the cytotoxicity of cisplatin and (Au(PPh(2)CH(2)CH(2)PPh(2))(2))Cl., Materials and Methods: The silver carboxylates (AgO(2)CCH(2)OCH(3)), 1, (AgO(2)C-CH(2)OCH(2)CH(2)OCH(3)), 2, and (AgO(2)CCH(2)OCH(2)CH(2)OCH(2)CH(2)OCH(3)), 3, were investigated. Cytotoxicity tests were performed on the HeLa (human cervix epitheloid) cancer cell line, resting lymphocytes and PHA (phytohaemagglutinin)-stimulated lymphocyte cultures. Cell survival was measured by means of the colorometric 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay., Results: The IC(50) (50% cell growth inhibition) values of 1-3 in the HeLa cells varied between 2.6 and 6.1 μmol dm(-3) with being 1 the most cytotoxic silver complex. Drug activity was inversely proportional to the length of the carboxylato chain length. Complexes 1-3 were 3-5 times more cytotoxic against the HeLa cancer cells than against the PHA stimulated lymphocyte cultures., Conclusion: A drug activity-structure relationship exists in that short-chain silver carboxylates are more cytotoxic than long-chain silver carboxylates, but silver d(10) complexes are one order of magnitude less cytotoxic than platinum(II) d(8) or gold(I) d(10) complexes.

Background: Ferrocene derivatives may possess antineoplastic activity. Those with low ferrocenyl reduction potentials often have the highest anticancer activity, as cell components have to oxidise them to the active ferrocenium species before cytotoxicity can be recorded. Some gold(I) complexes also possess anticancer activity. This study examined the cytotoxicity of ferrocenyl-ethynyl and ruthenocenyl-ethynyl complexes of gold and platinum. The results were related to the ease of iron oxidation in the ferrocenyl fragment and compared with the cytotoxicity of cisplatin, [(H(3)N)(2)PtCl(2)] and [Au(PPh(2)CH(2)CH(2)PPh(2))(2)]Cl., Materials and Methods: Ferrocene-containing gold and platinum complexes of the type Fc-C≡C-PPh(2), 1, and Fc-C≡C-PPh(2)→M with Fc=ferrocenyl (Fe(II)(η(5)-C(5)H(5)) (η(5)-C(5)H(4))), Ph=phenyl (C(6)H(5)) and M=Au-Cl, 2, Au-C≡C-Fc, 3, or Au-C≡C-Rc, 4 (Rc=ruthenocenyl, (Ru(II)(η(5)-C(5)H(5)) (η(5)-C(5)H(4))) and the complex [(Fc-C≡C-PPh(2))(2)PtCl(2)], 5, were investigated. Cytotoxicity tests were determined on the HeLa (human cervix epitheloid) cancer cell line, ATCC CCL-2. Cell survival was measured by means of the colorometric 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide assay., Results: The IC(50) values of compounds 1-4 from four experiments causing 50% cell growth inhibition, ranged between 4.6 and 27 μmol dm(-3). Drug activity was inversely proportional to the sum of all formal reduction potentials, E(o'), of the ferrocenyl groups of the Fc-C≡C-PPh(2) and Fc-C≡C-ligands coordinated to the gold centre. The Fc-C≡C-PPh(2)→Au-Cl complex, compound 2, was most cytotoxic with IC(50)=4.6 μmol dm(-3) , demonstrating the beneficial effect the Cl(-) ion has on the cytotoxicity of these neutral gold complexes. The platinum complex [(Fc-C≡C-PPh(2))(2)PtCl(2)], compound 5, resembling the structure of cisplatin, in principle should exhibit good cytotoxicity, but was not tested due to its total insolubility in any biocompatible medium.

The general synthetic strategy towards water-soluble biodegradable drug carriers and the properties that they must have are discussed. The syntheses of water-soluble biodegradable copolymers of lysine and aspartic acid as potential drug-delivering devices, having amine-functionalised side chains are then described. Covalent anchoring of carboxylic acid derivatives of the antineoplastic ferrocene and photodynamically active phthalocyanine moieties to the amine-containing drug carrier copolymers under mild coupling conditions has been achieved utilising the coupling reagent O-benzotriazolyl-N,N,N('),N(')-tetramethyluronium hexafluorophosphate to promote formation of the biodegradable amide bond. Even though the parent antineoplastic ferrocene and phthalocyanine derivatives are themselves insoluble in water at pH < 7, the new carrier-drug conjugates that were obtained are well water-soluble.