Unexpected Course of Reaction Between (1,3)-1,4-Dinitro-1,3-butadiene and N-Methyl Azomethine Ylide-A Comprehensive Experimental and Quantum-Chemical Study.

In recent times, interest in the chemistry of conjugated nitrodienes is still significantly increasing. In particular, the application of these compounds as building blocks to obtain heterocycles is a popular object of research. Therefore, in continuation of our research devoted to the topic of conjugated nitrodienes, experimental and quantum-chemical studies of a cycloaddition reaction between (1,3)-1,4-dinitro-1,3-butadiene and N-methyl azomethine ylide have been investigated.

New psychoactive substances - 96 cases of deaths related to their use based on the material originating from forensic toxicological practice.

Among the emerging investigative fields, forensic medicine and toxicology lead to analyzing fatalities in medico-legal expert opinion formulating. While discussing the problem, the authors have selected 96 fatal cases from their expert practice including the period from 2010 to 2023, in which deaths were connected with taking new psychoactive substances (NPS's) belonging to various chemical categories, mainly synthetic cathinones (SC), synthetic cannabinoids (SCan) and non-medical synthetic opioids (NSO). In the investigated cases, toxicological analysis revealed 37 NPS's and their 9 metabolites.

(1,3)-1,4-Dinitro-1,3-butadiene-Synthesis, Spectral Characteristics and Computational Study Based on MEDT, ADME and PASS Simulation.

The chemistry of conjugated nitrodienes is becoming increasingly popular. These molecules are successfully applied in cycloaddition to synthesize six-membered rings in Diels-Alder reactions. Nitrodienes can be also applied to obtain bis-compounds in [3+2] cycloaddition.

Interpretative problems due to the presence of chloromethcathinone isomers in the biological material from postmortem cases.

While many new psychoactive substances often disappear from the drug market rather quickly, some, such as synthetic cathinones (SCs), still remain due to their popularity among users. The current knowledge of SC concentrations in blood samples is based mainly on the published case reports of intoxications or fatalities caused by SC intake. The aim of the present study was to present and interpret the obtained toxicological analysis results of these cases, in which it was possible to determine or detect the presence of one of the isomers of chloromethcathinone (CMC) along with its intake biomarker-dihydro-CMC.

Arylcyanomethylenequinone Oximes: An Overview of Synthesis, Chemical Transformations, and Biological Activity.

Quinone methides are a class of biologically active compounds that can be used in medicine as antibacterial, antifungal, antiviral, antioxidant, and anti-inflammatory agents. In addition, quinone methides have the potential to be used as pesticides, dyes, and additives for rubber and plastics. In this paper, we discuss a subclass of quinone methides: methylenequinone oximes.

Stress Relaxation Behaviour Modeling in Rigid Polyurethane (PU) Elastomeric Materials.

Polyurethane (PU) has been used in a variety of industries during the past few years due to its exceptional qualities, including strong mechanical strength, good abrasion resistance, toughness, low-temperature flexibility, etc. More specifically, PU is easily "tailored" to satisfy particular requirements. There is a lot of potential for its use in broader applications due to this structure-property link.

(3+2)-Cyclization Reactions of Unsaturated Phosphonites with Aldehydes and Thioketones.

By exploiting the unique reactivity of ethynyl-phosphonites we obtain novel P(V)-containing five-membered heterocycles via (3+2)-cyclization reactions with aldehydes or cycloaliphatic thioketones in satisfactory to excellent yields. Whereas reactions with thioketones to yield 1,3-thiaphospholes-3-oxides occur smoothly at room temperature with equimolar amounts of the starting materials in absence of any catalyst, the analogous conversions with aldehydes to generate 3-oxides of 1,3-oxaphospholes require addition of triethylamine as a base. We postulate a step-wise (3+2)-cyclization mechanism for the formation of the 1,3-thiaphosphole ring based on DFT quantum chemical calculations.

Daily levels of sex hormones in 15 subfertile women formulate a menstrual cycle profile predominant with progesterone secretion.

Introduction: Changes in sex hormone secretions during the menstrual cycle may affect fertility. It has been shown that a prematurely raised progesterone (P4) level after therapeutic injection of human chorionic gonadotropin caused changes in endometrial gene expression and lowered the pregnancy rate. The aim of the present study was to investigate the complete menstrual patterns of P4 together with its derivatives testosterone (T) and oestradiol (E2) in subfertile women during their natural cycles.

The Stability of Synthetic Cathinones and the Study of Potential Intake Biomarkers in the Biological Material from a Case of 3-CMC Poisoning.

The objective of the present study was to identify the metabolites of synthetic cathinone (SC), 3-chloromethcathinone (3-CMC), and to select a potential intake biomarker for this compound. The basis of the experiment was the analysis of blood and urine samples from a case of fatal poisoning with this substance. We also evaluated the stability of 3-CMC and the selected potential biomarker, the dihydro-3-CMC metabolite, depending on the time elapsed since the autopsy as well as the storage conditions of the biological material.

On the Question of the Formation of Nitro-Functionalized 2,4-Pyrazole Analogs on the Basis of Nitrylimine Molecular Systems and 3,3,3-Trichloro-1-Nitroprop-1-Ene.

Experimental and theoretical studies on the reaction between ()-3,3,3-trichloro-1-nitroprop-1-ene and -(4-bromophenyl)-C-arylnitrylimine were performed. It was found that the title process unexpectedly led to 1-(4-bromophenyl)-3-phenyl-5-nitropyrazole instead of the expected Δ-pyrazoline molecular system. This was the result of a unique CHCl elimination process.

Expression of G-Protein-Coupled Estrogen Receptor () in Whole Testicular Tissue and Laser-Capture Microdissected Testicular Compartments of Men with Normal and Aberrant Spermatogenesis.

In this study, we retrospectively investigated expression in biopsies of azoospermic men with complete (obstructive azoospermia-OA) and aberrant spermatogenesis (nonobstructive azoospermia-NOA). Each biopsy was histologically evaluated with morphometry. The testicular expression was analyzed by the immunohistochemistry and RT-PCR technique in the whole testicular tissue and in seminiferous tubules and Leydig cells after laser-capture microdissection.

Rheological Relaxation of OSB Beams Reinforced with CFRP Composites.

An experimental and analytical approach to the relaxation problem of wood-based materials-OSB (Oriented Strand Boards-pressed wood-based composite panels) beams, including beams with CFRP (Carbon fiber reinforced polymer) tape composite reinforcement, is presented. It is a relevant engineering and scientific problem due to the fact that wood and wood-based materials, as well as composite reinforcements, are widely used in building constructions. Their rheological properties are very important and complicated to estimate.

The Participation of 3,3,3-Trichloro-1-nitroprop-1-ene in the [3 + 2] Cycloaddition Reaction with Selected Nitrile -Oxides in the Light of the Experimental and MEDT Quantum Chemical Study.

The regioselective [3 + 2] cycloaddition (32CA) reactions of a series of aryl-substituted nitrile -oxides (NOs) with trichloronitropropene (TNP) have been both experimentally and theoretically studied within the Molecular Electron Density Theory (MEDT). Zwitterionic NOs behave as moderate nucleophiles while TNP acts as a very strong electrophile in these polar 32CA reactions of forward electron density flux, which present moderate activation Gibbs free energies of 22.8-25.

A DFT Study on the Molecular Mechanism of Additions of Electrophilic and Nucleophilic Carbenes to Non-Enolizable Cycloaliphatic Thioketones.

The molecular mechanisms of addition of dihalocarbenes and dimethoxycarbene to thioketones derived from 2,2,4,4-tetrmethylcyclobutane-1,3-dione were examined on the basis of the DFT wb97xd/6-311g(d,p)(PCM) calculations. Obtained results demonstrated that the examined processes exhibit polar nature and in the case of electrophilic dichloro-, and dibromocarbenes are initiated by the attack of carbene species onto the sulfur atom of the C=S group. Remarkably, reactions involving more electrophilic carbenes (dichloro-, and dibromocarbene) proceeds via stepwise mechanism involving thiocarbonyl ylide as a transient intermediate.

Understanding the Participation of Fluorinated Azomethine Ylides in Carbenoid-Type [3 + 2] Cycloaddition Reactions with Ynal Systems: A Molecular Electron Density Theory Study.

The carbenoid-type () 32CA reaction of 1,1-difluoroated azomethine ylide (DFAY) with phenylpropynal has been studied using the molecular electron density theory (MEDT). Electron localization function (ELF) characterizes DFAY as a carbenoid species participating in 32CA reactions. The supernucleophilic character of DFAY and the strong electrophilic character of the ynal cause this polar 32CA reaction to have an unappreciable barrier; the reaction, which is highly exothermic, presents total chemo- and regioselectivity.

Experimental and Theoretical Mechanistic Study on the Thermal Decomposition of 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline.

The present paper is a continuation of comprehensive study regarding to synthesis and properties of pyrazoles and their derivatives. In its framework an experimental and theoretical studies of thermal decomposition of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline were performed. It was found, that the decompositions of the mentioned pyrazoline system in the solution and at the melted state proceed via completely different molecular mechanisms.

Influence of Boundary Conditions on Numerical Homogenization of High Performance Concrete.

Concrete is the most widely used construction material nowadays. We are concerned with the computational modelling and laboratory testing of high-performance concrete (HPC). The idea of HPC is to enhance the functionality and sustainability of normal concrete, especially by its greater ductility as well as higher compressive, tensile, and flexural strengths.

Forensic-psychiatric relationships in the context of forensic medical examination of new psychoactive substance-related deaths.

Introduction: The aim of this study was to find causal relationships between the use of new psychoactive substances (NPS), the so-called "legal highs", and the cause of death, taking into account information indicating the victim's mental disorders before death.

Material And Methods: The research material includes the results of toxicological analyses of blood samples collected during autopsies of 40 deceased persons whose cause of death was associated with the ingestion of new psychoactive substances (NPS). The blood samples were subjected to solid phase extraction (SPE), and then analyzed by liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) for quantification.

Increased Ethanol Consumption and Locomotion Develop upon Ethanol Deprivation in Rats Overexpressing the Adenosine (A) Receptor.

Preclinical data indicate that ethanol produces behavioral effects that can be regulated by many neurotransmitters and neuromodulators like adenosine (A). The most important receptors with respect to the rewarding effects of ethanol seem to be the A receptors. This study used a transgenic strategy, specifically rats overexpressing the A receptor, to characterize the neurobiological mechanisms of ethanol consumption as measured by intermittent access to 20% ethanol in a two-bottle choice paradigm.

Comparison of movement rate with different initial moment-to-force ratios.

Introduction: The objective of this clinical prospective study was to evaluate the effect of the 2 treatment strategies, translation or controlled tipping, followed by root correction on canine retraction efficiency, specifically canine movement rate.

Methods: Twenty-one patients who needed bilateral maxillary canine retraction to close extraction space as part of their treatment plan were selected for this study. Segmental T-loops designed for controlled tipping or for translation were applied randomly to each side.

Novel functionalized β-nitrostyrenes: Promising candidates for new antibacterial drugs.

The process of searching for new antibacterial agents is more and more challenging due to the increasing drug resistance which has become a major concern in the field of infection management. Our study presents a synthesis and characterization by IR, UV, H NMR and C NMR spectra of a homogenous series of 1-EWG functionalized 2-aryl-1-nitroethenes which could prove good candidates for the replacement of traditional antibacterial drugs against a panel of the reference strains of bacteria and fungi and their cytotoxicity towards cultured human HepG2 and HaCaT cells was performed. Antimicrobial results indicated that four of the synthesized compounds exhibited a significant antimicrobial activity against all tested reference bacteria and fungi belonging to yeasts with a specific and strong activity towards ATCC 6633.

Three-dimensional evaluation of labial alveolar bone overlying the maxillary and mandibular incisors in different skeletal classifications of malocclusion.

Objectives: The purpose of this study was to investigate differences in the thickness of the labial bone overlying the maxillary and mandibular incisors in class I, II, and III skeletal classifications using three-dimensional cone-beam computed tomographs (CBCT) technology.

Methods: Pretreatment CBCTs of 54 Caucasian subjects (44 males, 10 females) were collected from the archives of a graduate orthodontic clinic. The subjects were divided into three groups based on their skeletal classification.

Retrospective CBCT analysis of airway volume changes after bone-borne vs tooth-borne rapid maxillary expansion.

Objectives: To compare changes in upper airway volume after maxillary expansion with bone- and tooth-borne appliances in adolescents and to evaluate the dentoskeletal effects of each expansion modality.

Materials And Methods: This retrospective study included 36 adolescents who had bilateral maxillary crossbite and received bone-borne maxillary expansion (average age: 14.7 years) or tooth-borne maxillary expansion (average age: 14.