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Background: One of the most popular methods of local anesthesia in dentistry, inferior alveolar nerve block (IANB) involves the blockade of the inferior alveolar nerve (IAN) and lingual nerve (LN) in the pterygomandibular space. Despite the large number of works describing the contents of this space, the spatial displacements of the anatomical structures of this area at different positions of the mandible have not been sufficiently studied. The aim of our study was to study the spatial movements of the IAN and inferior alveolar artery (IAA) at various positions of the mandible using computer simulation and finite element analysis to find the safest way to conduct IANB., Materials and Methods: Reverse engineering was used to create a model of the cranial base and the mandible based on computed tomography (CT) data obtained from patient N (male, 24 years old), the arteries of the head and neck were designed from the data of multiphase angiography of patient M (female, 61 years old). Masticatory muscles, sphenomandibular ligament, temporomandibular joint and mandibular nerve were modeled in the SolidWorks software package based on an open database of anatomical structures. The finite element grid was generated in the Solidworks software. In the first series of experiments, the displacement of the mandible was modeled along the vertical axis down by 48 mm (maximum opening of the mouth), in the second series, the jaw was displaced vertically by 48 mm with a simultaneous transversal movement of 10 mm, in the third series, the jaw was displaced along the vertical axis down by 34 mm and transversally by 22 mm., Results: The largest distance between IAN and IAA was noted in the third series of experiments. The distance between the nerve and the vessel was minimal in the first series, with an open mouth without lateral displacements., Conclusion: The generated computer model opens new possibilities for studying the dynamic anatomy of the pterygomandibular space. The results of this study can be used for further experimental and clinical trials to find the safest approach to the implementation of IANB, as well as applied in the practice of the educational process., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

We propose a new technique for the detection of microorganisms by elemental composition analyses of a sample extracted from regolith, permafrost, and ice of extraterrestrial bodies. We also describe the design of the ABIMAS instrument, which consists of the onboard time-of-flight laser mass-reflectron (TOF LMR) and the sample preparation unit (SPU) for biomass extraction. This instrument was initially approved to fly on board the ExoMars 2020 lander mission. The instrument can be used to analyze the elemental composition of possible extraterrestrial microbial communities and compare it to that of terrestrial microorganisms. We have conducted numerous laboratory studies to confirm the possibility of biomass identification via the following biomarkers: P/S and Ca/K ratios, and C and N abundances. We underline that only the combination of these factors will allow one to discriminate microbial samples from geological ones. Our technique has been tested experimentally in numerous laboratory trials on cultures of microorganisms and polar permafrost samples as terrestrial analogues for martian polar soils. We discuss various methods of extracting microorganisms and sample preparation. The developed technique can be used to search for and identify microorganisms in different martian samples and in the subsurface of other planets, satellites, comets, and asteroids-in particular, Europa, Ganymede, and Enceladus. Key Words: Mass spectrometry-Life-detection instruments-Biomarkers-Earth Mars-Biomass spectra. Astrobiology 17, 448-458.

The reactions of 3-acetyl-3-aza-11-oxatricyclo[6.2.1.0(1,6)]undec-9-ene and its 9,10-epoxy derivative with bromine and Ac(2)O/BF(3).OEt(2) under different conditions were studied. Unusual products of Wagner-Meerwein rearrangement bearing the olefin fragment (5-aza-2-oxatricyclo[6.2.1.0(3,9)]undecen-3-enes) were isolated and characterized by X-ray analysis.