A Pd(II) Magnetically Retrievable Catalyst for Hiyama Reaction: Functionalization of Magnetic Mesoporous Silica via Click Reaction

Catalysis Letters - A nitrogen ligand, i.e. 1,3-di-(o-aminophenoxy)-2-propyl propargyl ether (DPPE), has been synthesized and characterized. Magnetic mesoporous silica composite (MNP@SiO2-SBA) was...     

Advances in Triboelectric Nanogenerators for Self-Powered Regenerative Medicine

Over the last decade, in pursuit to provide suitable alternatives for power supplies of medical devices in regenerative medicine, extensive research on nanogenerators has been developed. Such devices can overcome current commercial battery challenges, including intense heat-on-body complications due to the electrical current during therapeutic usage, leading to protein denaturation, cell structure destruction, and even cell necrosis. In addition, these traditional batteries contain a bulky and heavy structure that prevents them from providing sustainable on body biomedical therapeutic intervention. Furthermore, advantages such as wide-range biocompatible and biodegradable materials, lightweight, and sufficient stretchability for device construction can minimize the side effects of implantable devices, including inflammation or toxicity, as well as eliminate secondary surgery to replace or remove batteries. Triboelectric nanogenerators (TENGs) are associated with harvesting mechanical energy in various forms, among which human body motions can serve as a renewable power source for healthcare systems. This review is written to emphasize the importance of TENG's applications in regenerative medicine and modulation purposes, particularly for the nervous system. Some crucial parameters for implantable consideration are discussed. In the concluding remarks, features for clinical utilization including output efficiency, encapsulation, stability, and miniaturization are suggested as challenges and prospects.     

Porous conductive and biocompatible scaffolds on the basis of polycaprolactone and polythiophene for scaffolding

Polymer Bulletin - The fabrication of novel scaffolds was represented on the basis of conductive and biodegradable copolymers. The star-like polycaprolactone (S-PCL) was synthesized from...     

Highly selective hydrogen production from propane by Ru–Ni core–shell nanocatalyst deposited on reduced graphene oxide by sequential chemical vapor deposition

A narrow temperature window (160°C-190°C) was identified for the selective deposition of Ru on Ni supported on reduced graphene oxide (rGO) through a sequential chemical vapor deposition (CVD) method. Cyclopentadiene and cyclopentene were identified as decomposition products of nickelocene CVD on rGO, whereas only methane was detected in gaseous products from ruthenocene CVD. Heat treatment converted the selectively deposited Ru on Ni/rGO into Ru–Ni core–shell bimetallic system on the surface of rGO as confirmed by high-resolution transmission electron microscopy. The Ru–Ni/rGO thus prepared produced hydrogen with high selectivity in propane steam reforming performed in the temperature range of 350°C to 850°C. Addition of 3.6% Ru against Ni supported on rGO improved the turnover frequency (TOF) of propane up to 70% to 100% compared to the Ni/rGO catalyst at lower temperatures (350°C-450°C). The presence of Ru lowered the activation energy of propane SR from 65.7 kJ mol⁻¹ for Ni/rGO to 48.7 kJ mol⁻¹ for Ru–Ni/rGO catalyst.     

Urinary 2-ethyl-3-oxohexanoic acid as major metabolite of orally administered 2-ethylhexanoic acid in human

Human metabolism of 2-ethylhexanoic acid (2-EHA), which is a known metabolite of important phthalates, was investigated using 2-EHA-contaminated food. The results of our studies reveal that the major catabolic pathway of 2-EHA in human is beta-oxidation. The dominant final urinary metabolite was identified and quantified as 3-oxo-2-ethylhexanoic acid (3-oxo-2-EHA), but only after immediate methylation of the extract from urine and prior to GC-MS analysis. Former studies without the precaution of immediate methylation had found 4-heptanone as the major metabolite, which is obviously an artifact arising from the decarboxylation of 3-oxo-2-EHA.     

Removal of acid dyes from aqueous media by adsorption onto amino-functionalized nanoporous silica SBA-3

Adsorption of acid dyes on SBA-3 ordered mesoporous silica, ethylenediamine functionalized SBA-3 (SBA-3/EDA), aminopropyl functionalized SBA-3 (SBA-3/APTES) and pentaethylene hexamine functionalized SBA-3 (SBA-3/PEHA) materials has been studied. The structural order and textural properties of the synthesized materials have been studied by XRD, FT-IR and nitrogen adsorption-desorption analysis. The adsorption capacity of the adsorbents varies in the following order: SBA-3/PEHA > SBA-3/APTES > SBA-3/EDA > SBA-3. The SBA-3/PEHA is found to have the highest adsorption capacity for all acid dyes. The adsorption mechanism which is based on electrostatic attraction and hydrogen bonding is described. Batch studies were performed to study the effect of various experimental parameters such as chemical modification, contact time, initial concentration, adsorbent dose, agitation speed, solution pH and reaction temperature on the adsorption process. The Langmuir and Freundlich isotherm models have been applied and the Freundlich model was found to be fit with the equilibrium isotherm data. Kinetics of adsorption follows the second-order rate equation.     

Hydrogen sulfide sensing properties of multi walled carbon nanotubes

This paper investigates the effect of functional groups on the hydrogen sulfide sensing properties of multi-walled carbon nanotubes using carboxyl and amide groups and Mo and Pt nanoparticles as decorated precursors in gaseous state at working temperature. Carbon nanotubes were synthesized by the CVD process and decorated with the nano particles; provide higher sensitivity for H₂S gas detection. The MWCNTs were characterized by scanning electron microscopy combined with energy dispersive X-ray (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), ATR-IR absorption and Fourier transforms infrared (FT-IR) analyses. The MWCNTs were deposited as a thin film layer between prefabricated gold electrodes on alumina surfaces. The sensitivity of carbon nanotubes was measured for different H₂S gas concentrations and at working temperature. The results showed that the measured electrical conductance of the modified carbon nanotubes with functional groups is modulated by charge transfer with P-type semiconducting characteristics and metal decorated carbon nanotubes exhibit better performances compared to functional groups of carboxyl and amide for H₂S gas monitoring at room temperature.     

Shedding light on the poly(5-ethylidene-2-norbornene) microstructural differences: Skeleton rearrangements during polymerization

Here, an attempt is made to study one of the less noticed aspects of the polymerization of 5-ethylidene-2-norbornene (ENB) by nickel α-diimine catalysts. Therefore, several (co)polymerization runs using MMAO-activated binuclear catalyst (BNC) and mononuclear catalyst (MNC) were undertaken. Catalyst activities as high as 561.1 and 925.0 (kg_pol mol⁻¹_Ni h⁻¹) were observed for ENB polymerization by MNC and BNC, respectively. However, the utilization of comonomer (norbornene [NB]) led to a dramatic decline in the catalyst activities, reaching low levels of 69.4 and 144.4 (kg_pol mol⁻¹_Ni h⁻¹), respectively. Structural characterization (NMR and FTIR) corroborated the occurrence of ring opening via β-C elimination and the subsequent β-H elimination. Additionally, tandem transannular polymerization and ring-opening metathesis polymerization of ENB were evidenced. The findings demonstrated that the transannular polymerization prevailed during the polymerization, albeit the MNC catalyst showed a higher contribution of ring opening via β-C elimination. Importantly, comonomer (NB) was displayed to alter the governing polymerization mechanism. According to DMTA analysis, the structures of the monomer and catalyst were found to significantly influence the polymer damping behavior and microstructure heterogeneity. That is, the NB-ENB copolymer obtained by MNC exhibited the lowest T_g value and highest tan δ along with the diminished microstructure heterogeneity.     

Catalytic activity of multi-wall carbon nanotube supported manganese (III) porphyrin: an efficient,selective and reusable catalyst for oxidation of alkenes and alkanes with urea–hydrogen peroxide

Manganese complex of meso-tetrakis(4-hydroxyphenyl)porphyrin immobilised onto functionalised multi-wall carbon nanotubes (MWCNT) has been synthesised and characterised by elemental analysis, Fourier transform infrared (FT-IR), ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction and scanning electron microscopy. This catalyst, [Mn(THPP)OAc@MWCNT], was successfully applied for efficient epoxidation of alkenes and alkanes with urea–hydrogen peroxide. The role of the stoichiometric amounts of the acetic anhydride as an oxidant activator which introduce in situ peracetic acid has been discussed. This heterogeneous catalyst was highly reusable in the oxidation reactions and reused several times without significant loss of its catalytic activity.     

Introducing treatment strategy for cerebellar ataxia in mutant med mice: Combination of acetazolamide and 4-Aminopyridine

Purkinje neurons are the sole output neuron of the cerebellar cortex, and they generate high-frequency action potentials. Electrophysiological dysfunction of Purkinje neurons causes cerebellar ataxia. Mutant med mice have the lack of expression of the Scn8a gene. This gene encodes the NaV1.6 protein. In med Purkinje neurons, regular high-frequency firing is slowed, and med mice are ataxic. The aim of this study was to propose the neuroprotective drugs which could be useful for ataxia treatment in med mice, and to investigate the neuroprotective effects of these drugs by simulation. Simulation results showed that Kv4 channel inhibitors and BK channel activators restored the normal electrophysiological properties of the med Purkinje neurons. 4-Aminopyridine (4-AP) and acetazolamide (ACTZ) were proposed as neuroprotective drugs for Kv4 channel inhibitor and BK channel activator, respectively.