A Novel Rearrangement Reaction of Benzophenone Oxime upon Electron Impact

A »hidden« rearrangement reaction in benzophenone oxime was found by examination of a noncharactenistic, low abundance fragment ion

Synergistic Activity of Antibiotics and Bioactive Plant Extracts: A Study Against Gram-Positive and Gram-Negative Bacteria

The alarming growth of the number of antibiotic resistant bacteria and difficulties in treatment of infections have initiated a search for new antibacterial compounds and develop new alternative strategies in combating bacterial infections. Plant-derived compounds could exhibit a direct antibacterial activity and/or an indirect activity as antibiotic resistance modifying compounds, which, combined with antibiotics, increase their effectiveness. This ability of plant active substances reflects in modification or blocking of resistance mechanism so that bacterium becomes sensitive to antibiotic or the antibiotic acts when in lower concentrations. The systematic screening of plant-derived bioactive compounds, including those which can synergistically act with antibiotics, as resistance modifying agents represents a potential approach to overcome bacterial resistance. Therefore, the goals of this chapter are (i) an update of literature review on synergism between plant extracts and antibiotics, (ii) presentation of experimental results of synergistic activity of selected plant extracts and antibiotics and (iii) concluding remarks

Mass Spectra of Some Monosubstituted Benzophenone Oximes

The mass spectra of six benzophenone oximes substituted in the para-position with -NH2, -OCH3, -CH3, -Cl, -Br and -N02 have been studied. Introduction of a substituent into one of the aromatic rings enables the molecule to fragment by a variety of different reaction pathways. The influence of substitution on hydrogen and hydroxyl migration has been investigated. It ·is shown that electron-donating substituents enhance, while the electron-withdrawing substituents reduce both of these rearrangement reactions

Hybridization in Several Polycyclic Alkanes by the Method of Maximum Overlap

The hybridization · in spiropentane, nortricyclene, cu bane, tricyclo( l.1.0.02,4)butane, bicyclo(l.1.l)pentane, and tetracyclo(3,3.l 2, 8.04,6) nonane has been determined by the method of maximum overlap. For the atomic functions Clementi Orbitals (ref. 1) have been assumed. A comparison between these results and those, obtained previously, by assuming Slater orbitals indicates the improvements that can be achieved by using more exact wave functions. The overlaps for CC bonds fall into the groups: (1) S 0.64. They are characteristic of highly strained three-membered rings, (6 ~ 20°), of four membered rings, (b ~ 10°), and of normal or very slightly bent bonds, (6 < 5°), respectively

The Synthesis and Structure Determination of Tetrasubstituted 4,4\u27 -Biisoxazoles

Tetrasubstituted 4,4\u27-biisoxazoles were synthesized as a mixture of isomers by treatment of enolic tautomers of 3,4-diaroyl-2,5-hexanedione with hydroxylamine hydrochloride. A single isomer,· 3,3\u27- diphenyl-5,5\u27-dimethyl-4,4\u27-biisoxazole was isolated from the reaction product mixture. The structure of these compounds has been determined by spectrometric measurements (ir, 1H NMR and mass spectra). Mass spectra have been studied in detail. The determination of metastable transitions and accurate masses of important fragment ions led to the construction of fragmentation schemes

a-Hydrogen Exchange in the Re action of 2-Phenylethyldimethylsulphonium Ion with Base in Aqueous Solution and of 2-Phenylethyltrimethylammoni um Ion with Base in Aqueous and Alcoholic Solution

a-Hydrogen exch ange during the elimination from 2-phenylethyldimethylsulphonium bromide with on- in d euterium oxide h as been found to b e a lmost complete under certain r eactio n conditions. The product, trimethylamine, from the a n a logo u s reaction of 2-phenylethyltrimethylammonium iodide with eith er ethoxide ion in ethanol-0-d or with OD- in d~u terium oxide was found to contain no d etectabl e amount of deuterium above natural abundance

Prognostic significance of the serum levels of biochemical markers of brain injury in the early posttraumatic phase in patients with the traumatic brain injury

Uvod: Cilj studije je bio da se odrede serumske koncentracije proteina S100B i neuron specifične enolaze (NSE) i njihova sposobnost i preciznost u predikciji ranog neurološkog ishoda nakon traumatske lezije mozga. Materijal i metode: Stotrideset politraumatizovanih pacijenta sa udruženom traumatskom lezijom mozga je bilo uključeno u ovu prospektivnu kohortnu studiju. Serumski nivoi proteina S100B i NSE su mereni u 6, 24,48. i 72. satu nakon povređivanja. Rani neurološki ishod je procenjivan Glasgow Outcome Scale (GOS) skorom četrnaestog dana nakon povrede mozga. Rezultati: Koncentracije proteina S100B su bile maksimalne u 6. satu nakon povređivanja i praćene su naglim padom, a zatim sporijim oslobađanjem u naredna dva dana uz konstantno i signifikantno povišene vrednosti (p˂ 0.0001) kod pacijenata sa lošim ishodom. Sekundarni porast proteina S100B u 72. satu zabeležen je kod pacijenata koji su preminuli (GOS 1). Dinamiku promena za NSE karakteriše sekundarni porast koncentracija u 72. satu nakon povređivanja kod pacijenata sa lošim ishodom. Zaključak: Oba markera imaju dobru prediktivnu sposobnost lošeg neurološkog ishoda, mada NSE obezbeđuje bolji diskriminativni potencijal u 72. satu nakon povrede mozga, dok protein S100B ima bolji diskriminativni potencijal u predikciji mortaliteta.Background: The objective of our study was determination of serum concentrations of protein S100B and neuron specific enolase (NSE) as well as their ability and accuracy in prediction of an early neurological outcome after the traumatic brain injury. Methods: A total of 130 politraumatised patients with the associated traumatic brain injuries were included in this prospective cohort study. Serum protein S100B and NSE levels were measured at 6, 24, 48 and 72 hours after the injury. Early neurological outcome was scored by Glasgow Outcome Scale (GOS) on day 14 after the brain injury. Results: The protein S100B concentrations were maximal at 6 hours after the injury, followed there upon by abrupt fall, and subsequently by slower release in the following two days with continual and significantly increased values (p˂0.0001) in patients with poor outcome. Secondary increase of protein S100B at 72 hours was recorded in patients with lethal outcome (GOS 1). Dynamics of NSE changes was characterized by secondary increase of concentrations at 72 hours after the injury in patients with poor outcome. Conclusion: Both markers have good predictive ability for poor neurological outcome, although NSE provides better discriminative potential at 72 hours after the brain injury, while protein S100B has better discriminative potential for mortality prediction

Noncanonical DNA elements in the lamin B2 origin of DNA replication

DNA replication origins of eukaryotes lack linear replicator elements but contain short (dT)(n) (dA)(n) sequences that could build mutually equivalent unorthodox structures. Here we report that the lamin B2 origin of DNA replication adopts an alternative form characterized by unpaired regions CTTTTTTTTTTCC/GGAAAAAAAAAAG (3900-3912) and CCTTTTTTTTC/GAAAAAAAAGG (4141-4151). Both unpaired regions are resistant to DNase and except in central parts of their homopyrimidine strands are sensitive to single strand-specific chemicals. Interactions that protect central pyrimidines probably stabilize the bubble-like areas. Because DNA fragments containing either one or both bubbles migrate in TBM (89 mM Tris base, 89 mM boric acid, and 2 mM MgCl2) PAGE even faster than expected from their linear size, interacting regions are expected to belong to the same molecule. In an origin fragment containing a single bubble, free homopyrimidine strand can only interact with Hoogsteen hydrogen bonding surfaces from a complementary double stranded sequence. Indeed, this origin fragment reacts with triplex preferring antibody. In competition binding experiments control double stranded DNA or single stranded (dT) 40 do not affect origin-antibody interaction, whereas TAT and GGC triplexes exert competitive effect. Because the chosen fragment does not contain potential GGC forming sequences, these experiments confirm that the lamin B2 origin adopts a structure partly composed of intramolecular TAT triads

Modeliranje turbulentnog dvofaznog toka aero-smeše sprašenog uglja u gorioničkim kanalima sa jednostepenim turbulatorima

The subject of this work is turbulent two-phase flow through air-coal channel(s) of complex geometry. The aim of this work is numerical optimization of fluid flow and coal particle distribution in reconstructed air-coal mixture channels. The single blade turbulator has been used to increase turbulence in the vertical section of an air-coal mixture channel. Standard k-ω turbulent model has been used for modeling turbulence. Lagrangian multiphase model has been used for discrete phase (coal particles) modeling. Although better particle distribution is reached using single blade turbulators, particle concentration in the evaluation section (where plasma generators will be built in) still remains anisotropic. Because uniform coal particle distribution is of great importance for the proper work of plasma generators, other solutions for achieving this goal will be the object of the future analysis.Predmet ovog rada je turbulentno dvofazno strujanje kroz gorioničke kanale aero-smeše sprašenog uglja kompleksne geometrije. Cilj ovog rada je numerička optimizacija strujnog toka i raspodele čestica sprašenog uglja u rekonstruisanim gorioničkim kanalima. Za povećanje turbulencije, u vertikalnom delu gorioničkog kanala aero smeše ugrađen je jednostepeni turbulator. Za modeliranje turbulencije korišćen je standardni k-ω turbulentni model. Lagranžeov pristup je korišćen za modeliranje sekundarne faze (čestica sprašenog uglja). Iako je upotrebom jednostepenih turbulatora postignuta bolja raspodela čestica sprašenog uglja, koncentracija čestica u prelaznom delu (u kome će biti ugrađeni plazma generatori) ostaje neravnomerna. Kako je ravnomerna raspodela čestica sprašenog uglja od esencijalnog značaja za pravilan rad plazma generatora, druga rešenja za postizanje ravnomerne raspodele čestica će biti predmet buduće analize