Multimodal S(VI) Exchange Click Reactions Derived from SF Moieties: Comparative Kinetics and Stereochemistry of SuFEx and SuPhenEx Reactions.

The reaction mechanism of multimodal SuFEx and SuPhenEx click chemistries was investigated in detail for substitution of both the first and second fluoride or -nitrophenolate leaving groups in ∼RN = SOF and RN = SOF(-NO-phenol) substrates by temperature-dependent kinetics and density functional theory (DFT) calculations. Both the DFT calculations and the experimentally derived Δ indicate relatively small values for the activation enthalpies (4-15 kcal/mol), but almost constant and significant values of -Δ (10-14 kcal/mol). This indicates that depending on the precise nucleophile and S(VI) core, the reaction is either controlled by a mixture of enthalpy and entropy or basically is dominated by entropy alone.

Ultrafast, Selective, and Highly Sensitive Nonchromatographic Analysis of Fourteen Cannabinoids in Cannabis Extracts, Δ8-Tetrahydrocannabinol Synthetic Mixtures, and Edibles by Cyclic Ion Mobility Spectrometry-Mass Spectrometry.

The diversity of cannabinoid isomers and complexity of Cannabis products pose significant challenges for analytical methodologies. In this study, we developed a method to analyze 14 different cannabinoid isomers in diverse samples within milliseconds by leveraging the unique adduct-forming behavior of silver ions in advanced cyclic ion mobility spectrometry-mass spectrometry. The developed method achieved the separation of isomers from four groups of cannabinoids: Δ3-tetrahydrocannabinol (THC) (), Δ8-THC (), Δ9-THC (), cannabidiol (CBD) (), Δ8-iso-THC (), and Δ(4)8-iso-THC () (all MW = 314); 9α-hydroxyhexahydrocannabinol (), 9β-hydroxyhexahydrocannabinol (), and 8-hydroxy-iso-THC () (all MW = 332); tetrahydrocannabinolic acid (THCA) () and cannabidiolic acid (CBDA) () (both MW = 358); Δ8-tetrahydrocannabivarin (THCV) (), Δ8-iso-THCV (), and Δ9-THCV () (all MW = 286).

Ligand-Bound CO as a Nonclassical Route toward Efficient Photocatalytic CO Reduction with a Ni N-Confused Porphyrin.

Implementing the synergistic effects between the metal and the ligand has successfully streamlined the energetics for CO activation and gained high catalytic activities, establishing the important breakthroughs in photocatalytic CO reduction. Herein, we describe a Ni(II) N-confused porphyrin complex () featuring an acidic N-H group. It is readily deprotonated and exists in an anion form during catalysis.

Skeletons, Object Shape, Statistics.

Objects and object complexes in 3D, as well as those in 2D, have many possible representations. Among them skeletal representations have special advantages and some limitations. For the special form of skeletal representation called "s-reps," these advantages include strong suitability for representing slabular object populations and statistical applications on these populations.

Chitosan nanoparticles as a promising tool in nanomedicine with particular emphasis on oncological treatment.

The study describes the current state of knowledge on nanotechnology and its utilization in medicine. The focus in this manuscript was on the properties, usage safety, and potentially valuable applications of chitosan-based nanomaterials. Chitosan nanoparticles have high importance in nanomedicine, biomedical engineering, discovery and development of new drugs.

Comparison of third generation versus fourth generation electronic apex locators in detecting apical constriction: An in vivo study.

Aim: The aim of this in vivo study was to compare the accuracy of Root ZX and Raypex 5 in detecting minor diameter in human permanent single-rooted teeth.

Materials And Methods: Thirty-one patients with completely formed single-rooted permanent teeth indicated for extraction were selected for the study. Crown was flattened for stable reference point and access cavity prepared.

To evaluate and compare the efficacy, cleaning ability of hand and two rotary systems in root canal retreatment.

Aim: To evaluate and compare the efficacy, cleaning ability of hand and two rotary systems in root canal retreatment.

Methodology: Sixty extracted premolars were retreated with following systems: Group -ProTaper Universal retreatment files, Group 2-ProFile system, Group 3-H-file. Specimens were split longitudinally and amount of remaining gutta-percha on the canal walls was assessed using direct visual scoring with the aid of stereomicroscope.

Traumatic dental injury-an enigma for adolescents: a series of case reports.

Coronal fractures of permanent dentition are the most frequent type of dental injury. Fractured anterior teeth are usually treated with conventional post and core and crown techniques, after being treated endodontically. If the original tooth fragment is retained following fracture, the natural tooth structures can be reattached using adhesive protocols.

Platelet-Rich Fibrin with β-Tricalcium Phosphate-A Noval Approach for Bone Augmentation in Chronic Periapical Lesion: A Case Report.

Introduction. This paper describes a case of bone augmentation with combination of Platelet-Rich Fibrin (PRF) and β-TCP for treatment of chronic periapical cyst. The case was followed for 12 months.

An Unusual Mishap during Root Canal Access in Retreatment Case.

Varieties of objects have been introduced into the root canal system accidentally or intentionally; removal of these objects necessitates the success of the treatment. This paper explains an unusual bur fracture during nonsurgical endodontic treatment and its removal by ultrasonic energy with ease and without the removal of extra large amount of root dentin.

Management of exaggerated gagging in prosthodontic patients using glossopharyngeal nerve block.

When gag reflex becomes abnormally active, it poses difficulty for the prosthodontists, as it hinders the process of fixed partial denture construction beginning with tooth preparation till impression making. In this case-report, the authors used a nerve block technique which is popular among anaesthetist and otolaryngologist, but is being applied in the field of prosthodontics for the first time, to tide over the difficulty.