Material extrusion of thermoplastic acrylic for intraoral devices: Technical feasibility and evaluation.

With global demand for 3D printed medical devices on the rise, the search for safer, inexpensive, and sustainable methods is timely. Herein, we assessed the practicality of the material extrusion process for acrylic denture bases of which successful outcomes can be extended to implant surgical guides, orthodontic splints, impression trays, record bases and obturators for cleft palates or other maxillary defects. Representative materials comprising denture prototypes and test samples were designed and built with in-house polymethylmethacrylate filaments using varying print directions (PDs), layer heights (LHs) and reinforcements (RFs) with short glass fiber.

Machine Learning-Based Void Percentage Analysis of Components Fabricated with the Low-Cost Metal Material Extrusion Process.

Additive manufacturing (AM) is a widely used layer-by-layer manufacturing process. Material extrusion (ME) is one of the most popular AM techniques. Lately, low-cost metal material extrusion (LCMME) technology is developed to perform metal ME to produce metallic parts with the ME technology.

Nitroxide radicals appended to phthalonitriles: synthesis, structural characterization and photophysical properties.

The syntheses of 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl-2-yl)phenoxy]phthalonitrile (3, CHNO) and 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-2-yl)phenoxy]phthalonitrile (4) were carried out by microwave-assisted nucleophilic aromatic substitution of 4-nitrophthalonitrile (2) by the pre-formed 2-(4-hydroxyphenyl)-4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl (1). Compounds 3 and 4 were characterized unambiguously by a rich array of analyses, such as melting point, FT-IR, MALDI-TOF MS, elemental analysis, UV-Vis, CV, EPR, magnetic measurements and single-crystal X-ray diffraction. Structural studies demonstrate that the C-H.

Characterization of the Double Bond Conversion of Acrylic Resins for 3D Printing of Dental Prostheses.

Characterization of the double bond conversion of acrylic resins is considered critical in the evaluation of dental materials due to the propensity of end-use devices to accumulate residual monomer and degradation products that can cause local and systemic side effects in high doses. In this study, the authors examine two different acrylic-based photopolymers indicated for 3D printing of dental prostheses using Fourier transform infrared spectroscopy: a denture base material comprising ≥75% ethoxylated bisphenol A dimethacrylate, and a crown-and-bridge material composed of >60% proprietary methacrylic oligomer and 15%-25% 2-hydroxyethyl methacrylate. Infrared spectroscopy data showed a conversion rate (240 s) of 52.

Effect of the Substitution Pattern (Peripheral vs Non-Peripheral) on the Spectroscopic, Electrochemical, and Magnetic Properties of Octahexylsulfanyl Copper Phthalocyanines.

In order to investigate the substitution position effect on the spectroscopic, electrochemical, and magnetic properties of copper phthalocyanines, a detailed structure-property analysis has been performed by examining two copper phthalocyanines that are octasubstituted by hexylsulfanyl chains respectively in the peripheral (Cu-P) and non-peripheral (Cu-NP) positions. Cu-NP showed a marked near-IR maximum absorption compared to Cu-P and, accordingly, a smaller HOMO-LUMO energy gap, calculated via the electrochemical results and simulations in the gas phase, as well as for Cu-NP from its crystallographic data. An electron-spin resonance (ESR) technique is used to extract the g values from the powder spectra that are taken at room temperature.

Revisiting the Ullman's Radical Chemistry for Phthalocyanine Derivatives.

Phthalocyanine derivatives do not cease to gain attention due to their numerous properties and applications (e.g., sensor, PDT).

Synthetic Access to a Pure Polyradical Architecture: Nucleophilic Insertion of Nitronyl Nitroxide on a Cyclotriphosphazene Scaffold.

An optimized nucleophilic synthetic approach featuring mild conditions and microwave energy was utilized to circumvent the classical Ullman procedure and access a polynitronyl nitroxide radical easily and in pure form. The simultaneous controlled introduction of preformed nitronyl nitroxide radicals on a cyclotriphosphazene core leads to a novel polyphosphazene monomer which is suitable for both n- and a p-type redox-active material in organic rechargeable batteries as demonstrated by electrochemistry. Additionally, absorption spectra and square-wave voltammetry were utilized to quantify the number of nitronyl nitroxide radical units on the cyclotriphosphazene scaffold.

Structure-Photoproperties Relationship Investigation of the Singlet Oxygen Formation in Porphyrin-Fullerene Dyads.

A systematic structure-photoproperties relationship study of the interactions of porphyrin-fullerene dyads with molecular oxygen was conducted on a set of three porphyrin-fullerene dyads, as this approach of related applications - oxygen sensitivity and photo-induced singlet oxygen generation - of such dyads remained to be endeavoured. To promote energy transfers between the porphyrin and fullerene units and limit undesired charge separation, a particular attention was devoted to the choice of the solvents for the photoproperties determination. Toluene, in which in addition the compounds investigated are not aggregated, was selected accordingly.

Synthesis and Straightforward Quantification Methods of Imino Nitroxide-Based Hexaradical Architecture on a Cyclotriphosphazene Scaffold.

The synthesis of a homogeneous neutral hexaradical architecture consisting of six imino nitroxide radical moieties covalently bonded on a cyclotriphosphazene scaffold was reported. The synthesis of hexaradical imino nitroxide compounds follows the Ullman procedure involving the condensation of 2,3-bis(hydroxylamino)-2,3-dimethylbutane with hexa-(4-formylphenoxy)cyclotriphosphazene (3) followed by oxidation of the condensation product hexa-[4-(1-hydroxy-4,4,5,5-tetramethyl-2-imidazoline-2-yl)phenoxy]cyclotriphosphazene (2) by NaIO. Characterization of hexaradical was performed by X-ray and SQUID in solid state and by EPR, absorption spectroscopy, and electrochemistry in solution.

Carbonic anhydrase inhibitors: Design, synthesis, kinetic, docking and molecular dynamics analysis of novel glycine and phenylalanine sulfonamide derivatives.

The inhibition of two human cytosolic carbonic anhydrase isozymes I and II, with some novel glycine and phenylalanine sulfonamide derivatives were investigated. Newly synthesized compounds G1-4 and P1-4 showed effective inhibition profiles with KI values in the range of 14.66-315μM for hCA I and of 18.

Identification of subgingival periodontal pathogens and association with the severity of periodontitis in patients with chronic kidney diseases: a cross-sectional study.

Background: The aim of our study was to assess the subgingival profile of 9 periodontal pathogens, by means of real-time PCR, in a group of predialysis chronic kidney disease patients with and without periodontal disease and to identify the risk factors associated with periodontal disease in these patients.

Material And Methods: This is a single centre cross-sectional cohort study performed on 70 CKD patients. Patients received a full-mouth periodontal examination and the following parameters were assessed: periodontal pocket depth (PPD), clinical attachment level, bleeding on probing, and plaque index; subgingival biofilm samples were collected from the deepest periodontal pocket of each quadrant and were pooled in one transporting unit.

Synthesis of 3,4-dihydroxypyrrolidine-2,5-dione and 3,5-dihydroxybenzoic acid derivatives and evaluation of the carbonic anhydrase I and II inhibition.

The inhibition of two human cytosolic carbonic anhydrase (hCA, EC 4.2.1.

Periodontal disease: a covert source of inflammation in chronic kidney disease patients.

The prevalence of atherosclerotic complications (myocardial infarction, stroke, and sudden death) is increased in end-stage renal disease (ESRD) patients, especially in haemodialysis patients. Increasing evidence suggests that both in general population and in dialysis patients, systemic inflammation plays a dominant role in the pathogenesis of atherosclerotic complications. In general population, also, evidence shows that moderate to severe periodontitis can contribute to inflammatory burden by increasing serum CRP levels and may increase the prevalence of atherosclerotic events.

Kinetic and in silico analysis of thiazolidin-based inhibitors of α-carbonic anhydrase isoenzymes.

Carbonic anhydrases (CAs, EC 4.2.1.

Effect of substituents on spin density in benzimidazole nitronyl nitroxide radicals studied by electron spin resonance.

Several novel benzimidazole-3-oxide-1-oxyl radicals with substituents at 5 and/or 6 position were synthesized. The ESR analysis of nitrogen hyperfine coupling constants (hfccs) revealed that substituents at 5 and 6-position affect the spin density to greater extent than substituents on the phenyl ring at 2-position. Density functional theory calculations of nitrogen hfccs were performed using several different Pople type basis sets, as well as double and triple zeta quality individual gauge for localized orbital (IGLO-II, IGLO-III) and electron paramagnetic resonance (EPR-II, EPR-II) basis sets.