Photochemistry of Furyl- and Thienyldiazomethanes: Spectroscopic Characterization of Triplet 3-Thienylcarbene

Photolysis (λ \u3e 543 nm) of 3-thienyldiazomethane (1), matrix isolated in Ar or N2 at 10 K, yields triplet 3-thienylcarbene (13) and α-thial-methylenecyclopropene (9). Carbene 13 was characterized by IR, UV/vis, and EPR spectroscopy. The conformational isomers of 3-thienylcarbene (s-E and s-Z) exhibit an unusually large difference in zero-field splitting parameters in the triplet EPR spectrum (|D/hc| = 0.508 cm–1, |E/hc| = 0.0554 cm–1; |D/hc| = 0.579 cm–1, |E/hc| = 0.0315 cm–1). Natural Bond Orbital (NBO) calculations reveal substantially differing spin densities in the 3-thienyl ring at the positions adjacent to the carbene center, which is one factor contributing to the large difference in D values. NBO calculations also reveal a stabilizing interaction between the sp orbital of the carbene carbon in the s-Z rotamer of 13 and the antibonding σ orbital between sulfur and the neighboring carbon—an interaction that is not observed in the s-E rotamer of 13. In contrast to the EPR spectra, the electronic absorption spectra of the rotamers of triplet 3-thienylcarbene (13) are indistinguishable under our experimental conditions. The carbene exhibits a weak electronic absorption in the visible spectrum (λmax = 467 nm) that is characteristic of triplet arylcarbenes. Although studies of 2-thienyldiazomethane (2), 3-furyldiazomethane (3), or 2-furyldiazomethane (4) provided further insight into the photochemical interconversions among C5H4S or C5H4O isomers, these studies did not lead to the spectroscopic detection of the corresponding triplet carbenes (2-thienylcarbene (11), 3-furylcarbene (23), or 2-furylcarbene (22), respectively)

SSR analysis of the genomic DNA of perspective Uzbek hexaploid winter wheat varieties

The objective of this study was to investigate the genetic diversity of hexaploid wheat varieties of Uzbekistan breeding using simple sequence repeat (SSR) markers. These varieties are adapted to local conditions, and can be considered as the most important supplier of genetic resources for cultivation in Uzbekistan and other countries. Microsatellite markers are now most widely used and effective classes of DNA markers for genotyping, certification and classification of plant varieties. In this paper, genotyping results of 32 hexaploid wheat domestic varieties using 144 microsatellite primer pairs are presented. Microsatellite primer pairs were chosen from literature data and 36 primer pairs (from 144) gave polymorphic well-reproducible PCR-fragments. The individual SSR spectra differing in number of amplicons were obtained for each variety. A total number of 141 alleles for 36 microsatellite loci were detected. The number of alleles per locus ranged from 2 to 6, the mean number of alleles per locus (Na) was 3 alleles. For the studied genotypes group the effective number of alleles (ne) characterizing the loci by the allele frequency, varied from 1.7 to 4.8, the mean number of alleles per locus was 2.8. The expected heterozygosity (He) ranged from 0 to 0.792, averaging 0.626, in studied wheat population. The amplified fragment sizes ranged from 93 to 552 bp. The polymorphic index content (PIC) ranged from 0 to 0.758. A dendrogram was constructed using the alleles set of microsatellite loci, reflecting the phylogenetic differences of the studied hexaploid wheat varieties. It showed that Uzbekistan breeding varieties are divided into two main clusters, which may be evidence of their common origin.  A genetic formula has been developed for each Uzbek wheat variety. It can be used for identification, certification of these varieties, as well as for the selection of parental pairs in the wheat breeding programs

GeantV: Results from the prototype of concurrent vector particle transport simulation in HEP

Full detector simulation was among the largest CPU consumer in all CERN experiment software stacks for the first two runs of the Large Hadron Collider (LHC). In the early 2010's, the projections were that simulation demands would scale linearly with luminosity increase, compensated only partially by an increase of computing resources. The extension of fast simulation approaches to more use cases, covering a larger fraction of the simulation budget, is only part of the solution due to intrinsic precision limitations. The remainder corresponds to speeding-up the simulation software by several factors, which is out of reach using simple optimizations on the current code base. In this context, the GeantV R&D project was launched, aiming to redesign the legacy particle transport codes in order to make them benefit from fine-grained parallelism features such as vectorization, but also from increased code and data locality. This paper presents extensively the results and achievements of this R&D, as well as the conclusions and lessons learnt from the beta prototype.Comment: 34 pages, 26 figures, 24 table

Emulsion sheet doublets as interface trackers for the OPERA experiment

New methods for efficient and unambiguous interconnection between electronic counters and target units based on nuclear photographic emulsion films have been developed. The application to the OPERA experiment, that aims at detecting oscillations between mu neutrino and tau neutrino in the CNGS neutrino beam, is reported in this paper. In order to reduce background due to latent tracks collected before installation in the detector, on-site large-scale treatments of the emulsions ("refreshing") have been applied. Changeable Sheet (CSd) packages, each made of a doublet of emulsion films, have been designed, assembled and coupled to the OPERA target units ("ECC bricks"). A device has been built to print X-ray spots for accurate interconnection both within the CSd and between the CSd and the related ECC brick. Sample emulsion films have been extensively scanned with state-of-the-art automated optical microscopes. Efficient track-matching and powerful background rejection have been achieved in tests with electronically tagged penetrating muons. Further improvement of in-doublet film alignment was obtained by matching the pattern of low-energy electron tracks. The commissioning of the overall OPERA alignment procedure is in progress.Comment: 19 pages, 19 figure

Measurement of the atmospheric muon charge ratio with the OPERA detector

The OPERA detector at the Gran Sasso underground laboratory (LNGS) was used to measure the atmospheric muon charge ratio in the TeV energy region. We analyzed 403069 atmospheric muons corresponding to 113.4 days of livetime during the 2008 CNGS run. We computed separately the muon charge ratio for single and for multiple muon events in order to select different energy regions of the primary cosmic ray spectrum and to test the charge ratio dependence on the primary composition. The measured charge ratio values were corrected taking into account the charge-misidentification errors. Data have also been grouped in five bins of the "vertical surface energy". A fit to a simplified model of muon production in the atmosphere allowed the determination of the pion and kaon charge ratios weighted by the cosmic ray energy spectrum.Comment: 14 pages, 10 figure

The detection of neutrino interactions in the emulsion/lead target of the OPERA experiment

The OPERA neutrino detector in the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode through the study of $\nu_\mu\to\nu_\tau$ oscillations. The apparatus consists of an emulsion/lead target complemented by electronic detectors and it is placed in the high energy long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. Runs with CNGS neutrinos were successfully carried out in 2007 and 2008 with the detector fully operational with its related facilities for the emulsion handling and analysis. After a brief description of the beam and of the experimental setup we report on the collection, reconstruction and analysis procedures of first samples of neutrino interaction events

Острый билиарный панкреатит: эволюция хирургической тактики (обзор литературы)

Surgical treatment of acute biliary pancreatitis over the past decades have been improved from realization of open traumatic surgical interventions to the use of minimally invasive technologies. However, despite the progress in the treatment of this pathology, the question of the timing of cholecystectomy after endoscopic papillosphincterotomy with lithoextraction remains unresolved. In some cases, after the endoscopic papillosphincterotomy, a recurrence of the disease occurs, as well as other various biliary complications, such as: acute calculous cholecystitis, choledocholithiasis, cholangitis, associated with the fact that the main etiological factor – the gallstone disease – has not been eliminated, specifically, cholecystectomy was not performed.The objective of this study was to analyze the evolution of surgical tactics in the treatment of acute biliary pancreatitis with combined cholecystocholedocholithiasis.Хирургическое лечение острого билиарного панкреатита (ОБП) на протяжении последних десятилетий совершенствовалось от выполнения травматичных открытых оперативных вмешательств до применения малоинвазивных технологий. Однако, несмотря на прогресс в лечении данной патологии, остается не решенным вопрос о сроках выполнения холецистэктомии после проведенной эндоскопической папиллосфинктеротомии (ЭПСТ) с литоэкстракцией. В ряде случаев после ЭПСТ возникает рецидив заболевания, а также различные другие билиарные осложнения, такие как острый калькулезный холецистит, холедохолитиаз, холангит, связанные с тем, что остается не устранен основной этиологический фактор – желчнокаменная болезнь, а именно – не выполнена холецистэктомия.Цель исследования – проанализировать эволюцию хирургической тактики в лечении ОБП при сочетанном холецистохоледохолитиазе

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

Constructing a new understanding of the environment under postsocialism

This paper introduces a special grouping of papers on the theme of the environment and postsocialism. After the collapse of state socialism in Europe between 1989 and 1991, many immediate approaches to environmental reconstruction assumed that economic liberalisation and democratisation would alleviate problems. Since then, critics have argued that these proposed solutions were themselves problematic, and too closely reflected Western European and North American conceptions of environmental quality and democracy. The result has been a counterreaction focusing on detail and specificity at national levels and below. In this paper, we summarise debates about the environment and postsocialism since the period 1989 - 91. In particular, we examine whether an essentialistic link can be made between state socialism and environmental problems, and how far civil society -- or environmentalism -- may result in an improvement in perceived environmental quality. Finally, we consider the possibility for developing an approach to the environment and postsocialism that lies between crude generalisation and microscale studies