The collision induced loss of carbon monoxide from deprotonated benzyl benzoate in the gas phase. An anionic 1,2-Wittig type rearrangement

The ion PhCO2--CHPh, upon collision activation, undergoes competitive losses of CO and CO2 of which the former process produces the base peak of the spectrum. Product ion and substituent effect (Hammett) studies indicate that PhCO2--CHPh cyclises to a deprotonated hydroxydiphenyloxirane which ring opens to PhCOCH(O-)Ph. This anion then undergoes an anionic 1,2-Wittig type rearrangement {through [PhCO- (PhCHO)]} to form Ph2CHO- and CO. The mechanism of the 1,2-rearrangement has been probed by an ab initio study [at MP4(SDTQ)/6-31++G(d,p) level] of the model system HCOCH2O- →; MeO- + CO The analogous system RCO2--CHPh (R = alkyl) similarly loses CO, and the migratory aptitudes of the alkyl R groups in this reaction are Bu′ > Me > Et ∼Pri). This trend correlates with the order of anion basicities (i.e. the order of ΔG○acid values of RH), supporting the operation of an anion migration process. The loss of CO2 from PhCO2--CHPh yields Ph2CH- as the anionic product: several mechanistic scenarios are possible, one of which involves an initial ipso nucleophilic substitution.

Concerted HO2 elimination from alpha-Aminoalkylperoxyl free radicals : Experimental and theoretical evidence from the gas phase NH2 center dot CHCO2- + O-2 reaction

We have investigated the gas-phase reaction of the alpha-aminoacetate (glycyl) radical anion (NH2(sic)CHCO2-) with O-2 using ion trap mass spectrometry, quantum chemistry, and statistical reaction rate theory. This radical is found to undergo a remarkably rapid reaction with O-2 to form the hydroperoxyl radical (HO2(sic)) and an even-electron imine (NHCHCO2-), with experiments and master equation simulations revealing that reaction proceeds at the ion molecule collision rate. This reaction is facilitated by a low-energy concerted HO2(sic) elimination mechanism in the NH2CH(OO(sic))CO2- peroxyl radical. These findings can explain the widely observed free-radical-mediated oxidation of simple amino acids to amides plus alpha-keto acids (their imine hydrolysis products). This work also suggests that imines will be the main intermediates in the atmospheric oxidation of primary and secondary amines, including amine carbon capture solvents such as 2-aminoethanol (commonly known as monoethanolamine, or MEA), in a process that avoids the ozone-promoting conversion of (sic)NO to (sic)NO2 commonly encountered in peroxyl radical chemistry.

4-hexylbithieno[3,2-b:2′3′-e]pyridine: An efficient electron-accepting unit in fluorene and indenofluorene copolymers for light-emitting devices

4-Hexylbithienopyridine has been prepared as a novel electron-accepting monomer for conjugated polymers. To test its electronic properties, alternating copolymers with fluorene and indenofluorene polymers have been prepared. The copolymers displayed reduction potentials about 0.5 V lower than for the corresponding fluorene and indenofluorene homopolymers, indicating much improved electron-accepting properties. Analysis of the microscopic morphology of thin films of the copolymers by AFM shows that they lack the extensive supramolecular order seen with the homopolymers, which is attributed to the bithienopyridine units disrupting the π-stacking. LEDs using these polymers as the emitting layer produce blue-green emission with low turn-on voltages with aluminum electrodes confirming their improved electron affinity. The indenofluorene copolymer displayed an irreversible red shift in emission at high voltages, which is attributed to oxidation of the indenofluorene units. This red shift occurred at higher potentials than for indenofluorene homopolymers in LEDs, suggesting that the heterocyclic moieties offer some protection against electrically promoted oxidation.

How innovation and R&D happen in the upstream oil & gas industry : insights from a global survey

Few would disagree that the upstream oil & gas industry has become more technology-intensive over the years. But how does innovation happen in the industry? Specifically, what ideas and inputs flow from which parts of the sector׳s value network, and where do these inputs go? And how do firms and organizations from different countries contribute differently to this process? This paper puts forward the results of a survey designed to shed light on these questions. Carried out in collaboration with the Society of Petroleum Engineers (SPE), the survey was sent to 469 executives and senior managers who played a significant role with regard to R&D and/or technology deployment in their respective business units. A total of 199 responses were received from a broad range of organizations and countries around the world. Several interesting themes and trends emerge from the results, including: (1) service companies tend to file considerably more patents per innovation than other types of organization; (2) over 63% of the deployed innovations reported in the survey originated in service companies; (3) neither universities nor government-led research organizations were considered to be valuable sources of new information and knowledge in the industry׳s R&D initiatives, and; (4) despite the increasing degree of globalization in the marketplace, the USA still plays an extremely dominant role in the industry׳s overall R&D and technology deployment activities. By providing a detailed and objective snapshot of how innovation happens in the upstream oil & gas sector, this paper provides a valuable foundation for future investigations and discussions aimed at improving how R&D and technology deployment are managed within the industry. The methodology did result in a coverage bias within the survey, however, and the limitations arising from this are explored.

Copper(II) Complexes of l-Arginine as Netropsin Mimics Showing DNA Cleavage Activity in Red Light

Copper(II) complexes [Cu(L-arg)(2)](NO3)(2) (1) and [Cu(L-arg)(B)Cl]Cl (2-5), where B is a heterocyclic base, namely, 2,2'-bipyridine (bpy, 2), 1,10-phenanthroline (phen, 3), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 4), and dipyrido[3,2-a:2',3'-c)phenazine (dppz, 5), are prepared and their DNA binding and photoinduced DNA cleavage activity studied. Ternary complex 3, structurally characterized using X-ray crystallography, shows a square-pyramidal (4 + 1) coordination geometry in which the N,O-donor L-arginine and N,N-donor 1,10-phenanthroline form the basal plane with one chloride at the elongated axial site. The complex has a pendant cationic guanidinium moiety. The one-electron paramagnetic complexes display a metal-centered d-d band in the range of 590-690 nm in aqueous DMF They show quasireversible cyclic voltammetric response due to the Cu(II)/Cu(I) couple in the range of -0.1 to -0.3 V versus a saturated calomel electrode in a DMF-Tris HCl buffer (pH 7.2). The DNA binding propensity of the complexes is studied using various techniques. Copper(II) bis-arginate 1 mimics the minor groove binder netropsin by showing preferential binding to the AT-rich sequence of double-strand (ds) DNA. DNA binding study using calf thymus DNA gives an order: 5 (L-arg-dppz) >= 1 (biS-L-arg) > 4 (L-arg-dpq) > 3 (L-arg-phen) >> 2 (L-arg-bpy). Molecular docking calculations reveal that the complexes bind through extensive hydrogen bonding and electrostatic interactions with ds-DNA. The complexes cleave supercoiled pUC19 DNA in the presence of 3-mercaptopropionic acid as a reducing agent forming hydroxyl ((OH)-O-center dot) radicals. The complexes show oxidative photoinduced DNA cleavage activity in UV-A light of 365 nm and red light of 647.1 nm (Ar-Kr mixed-gas-ion laser) in a metal-assisted photoexcitation process forming singlet oxygen (O-1(2)) species in a type-II pathway. All of the complexes, barring complex 2, show efficient DNA photocleavage activity. Complexes 4 and 5 exhibit significant double-strand breaks of DNA in red light of 647.1 nm due to the presence of two photosensitizers, namely, L-arginine and dpq or dppz in the molecules.

Two stage Gifford-McMahon cycle cryorefrigerator operating at 20 K

A two stage Gifford-McMahon cycle cryorefrigerator operating at 20 K is described. This refrigerator uses a very simple ‘spool valve’ and a modified indigenous compressor to compress helium gas. This cryorefrigerator reaches a lowest temperature of 15.5 K; it takes ≈ 50 min to reach 20 K and the cooling capacity is ≈ 2.5 W at 25 K. The cool-down characteristics and load characteristics are presented in graphical form. The effect of changing the operating pressure ratio and the second stage regenerator matrix size are also reported. Pressure-volume (P-V) diagrams obtained at various temperatures indicate that P-V losses form the major fraction of the total losses and this becomes more pronounced as the temperature is decreased. A heat balance analysis shows the relative magnitudes of various losses.

Validation and development of PigBal model - Stage 2

The proposed project involves validate and upgrading the PigBal model to improve the accuracy of manure and GHG production predictions.

Delivering information and technology to the mango industry - Stage 2

Access to relevant and timely information and training resources has emerged as a significant issue from the Delivering Mango Technology (DMT) project. This project will facilitate providing managing information and technology tools for growers. Using a range of methods, including workshops, events, and web based technology facilitated through the Australian Mango Industry Association’s (AMIA) website, DMT stage 2 will develop a high profile delivery vehicle to building industry knowledge and resources .

Changes in straylight and corneal light scattering in a newly diagnosed case of type 2 diabetes

Visual problems may be the first symptoms of diabetes. There have been several reports of transient changes in refraction of people newly diagnosed with diabetes. Visual acuity and refraction may be affected when there are ocular biometric changes. Small but significant biometrical changes have been found by some authors during hyperglycaemia and during reduction of hyperglycaemia.[4] Here, we describe a case of type 2 diabetes that was detected from ocular straylight and intraocular thickness measurements...

Molecular Tuning of Rhodopsins for High Visual Sensitivity in Different Light Environments : Variation in Absorbance Spectrum and Opsin Sequence within and between Species

Visual pigments of different animal species must have evolved at some stage to match the prevailing light environments, since all visual functions depend on their ability to absorb available photons and transduce the event into a reliable neural signal. There is a large literature on correlation between the light environment and spectral sensitivity between different fish species. However, little work has been done on evolutionary adaptation between separated populations within species. More generally, little is known about the rate of evolutionary adaptation to changing spectral environments. The objective of this thesis is to illuminate the constraints under which the evolutionary tuning of visual pigments works as evident in: scope, tempo, available molecular routes, and signal/noise trade-offs. Aquatic environments offer Nature s own laboratories for research on visual pigment properties, as naturally occurring light environments offer an enormous range of variation in both spectral composition and intensity. The present thesis focuses on the visual pigments that serve dim-light vision in two groups of model species, teleost fishes and mysid crustaceans. The geographical emphasis is in the brackish Baltic Sea area with its well-known postglacial isolation history and its aquatic fauna of both marine and fresh-water origin. The absorbance spectrum of the (single) dim-light visual pigment were recorded by microspectrophotometry (MSP) in single rods of 26 fish species and single rhabdoms of 8 opossum shrimp populations of the genus Mysis inhabiting marine, brackish or freshwater environments. Additionally, spectral sensitivity was determined from six Mysis populations by electroretinogram (ERG) recording. The rod opsin gene was sequenced in individuals of four allopatric populations of the sand goby (Pomatoschistus minutus). Rod opsins of two other goby species were investigated as outgroups for comparison. Rod absorbance spectra of the Baltic subspecies or populations of the primarily marine species herring (Clupea harengus membras), sand goby (P. minutus), and flounder (Platichthys flesus) were long-wavelength-shifted compared to their marine populations. The spectral shifts are consistent with adaptation for improved quantum catch (QC) as well as improved signal-to-noise ratio (SNR) of vision in the Baltic light environment. Since the chromophore of the pigment was pure A1 in all cases, this has apparently been achieved by evolutionary tuning of the opsin visual pigment. By contrast, no opsin-based differences were evident between lake and sea populations of species of fresh-water origin, which can tune their pigment by varying chromophore ratios. A more detailed analysis of differences in absorbance spectra and opsin sequence between and within populations was conducted using the sand goby as model species. Four allopatric populations from the Baltic Sea (B), Swedish west coast (S), English Channel (E), and Adriatic Sea (A) were examined. Rod absorbance spectra, characterized by the wavelength of maximum absorbance (λmax), differed between populations and correlated with differences in the spectral light transmission of the respective water bodies. The greatest λmax shift as well as the greatest opsin sequence difference was between the Baltic and the Adriatic populations. The significant within-population variation of the Baltic λmax values (506-511 nm) was analyzed on the level of individuals and was shown to correlate well with opsin sequence substitutions. The sequences of individuals with λmax at shorter wavelengths were identical to that of the Swedish population, whereas those with λmax at longer wavelengths additionally had substitution F261F/Y in the sixth transmembrane helix of the protein. This substitution (Y261) was also present in the Baltic common gobies and is known to redshift spectra. The tuning mechanism of the long-wavelength type Baltic sand gobies is assumed to be the co-expression of F261 and Y261 in all rods to produce ≈ 5 nm redshift. The polymorphism of the Baltic sand goby population possibly indicates ambiguous selection pressures in the Baltic Sea. The visual pigments of all lake populations of the opossum shrimp (Mysis relicta) were red-shifted by 25 nm compared with all Baltic Sea populations. This is calculated to confer a significant advantage in both QC and SNR in many humus-rich lakes with reddish water. Since only A2 chromophore was present, the differences obviously reflect evolutionary tuning of the visual protein, the opsin. The changes have occurred within the ca. 9000 years that the lakes have been isolated from the Sea after the most recent glaciation. At present, it seems that the mechanism explaining the spectral differences between lake and sea populations is not an amino acid substitution at any other conventional tuning site, but the mechanism is yet to be found.

Anaerobic DNA cleavage activity in red light and photocytotoxicity of (pyridine-2-thiol)cobalt(III) complexes of phenanthroline bases

Cobalt(III) complexes [Co(pnt)(B)(2)](NO3)(2) (1-3) of pyridine-2-thiol (pnt) and phenanthroline bases (B), viz. 1,10-phenanthroline (phen in 1), dipyrido[3,2-d: 2',3'-f]quinoxaline (dpq in 2) and dipyrido[3,2-a:2',3'-c] phenazine (dppz in 3), have been prepared, characterized and their photo-induced anaerobic DNA cleavage activity studied. The crystal structure of 1a as mixed ClO4- and PF6- salt of 1 shows a (CoN5S)-N-III coordination geometry in which the pnt and phen showed N,S- and N,N-donor binding modes, respectively. The complexes exhibit Co(III)/Co(II) redox couple near -0.3 V (vs. SCE) in 20% DMF-Tris-HCl buffer having 0.1 M TBAP. The complexes show binding propensity to calf thymus DNA giving K-b values within 2.2 x 10(4)-7.3 x 10(5) M-1. Thermal melting and viscosity data suggest DNA surface and/or groove binding of the complexes. The complexes show significant anaerobic DNA cleavage activity in red light under argon atmosphere possibly involving sulfide anion radical or thiyl radical species. The DNA cleavage reaction under aerobic medium in red light is found to involve both singlet oxygen and hydroxyl radical pathways. The dppz complex 3 shows non-specific BSA and lysozyme protein cleavage activity in UV-A light of 365 nm via both hydroxyl and singlet oxygen pathways. The dppz complex 3 exhibits photocytotoxicity in HeLa cervical cancer cells giving IC50 values of 767 nM and 19.38 mu M in UV-A light of 365 nm and in the dark, respectively. A significant reduction of the dark toxicity of the dppz base (IC50 = 8.34 mu M in dark) is observed on binding to the cobalt(III) center.

Experimental studies on a two stage pulse tube cryocooler reaching 2.5K

A two stage Pulse Tube Cryocooler (PTC) is designed and fabricated which reaches a no-load temperature of 2.5K in the second stage and similar to 60 K in the first stage respectively. The system provides a cooling power of similar to 250 mW at 5K in the second stage. Stainless steel meshes (size 200) and lead (Pb) granules are used as the first stage regenerator materials and combination of Pb with Er3Ni / HoCu2 are used as the second stage regenerator materials. The system operates at 1.6 Hz using a 6 kW water cooled helium compressor. Studies conducted by varying the dimensions of Pulse Tubes and regenerators show that the dimensions of the Pulse Tubes are more critical to the performance of the Cryocooler than those of the regenerators. Experimental studies show that the optimum volume ratios of Er3Ni to Pb and HoCu2 to Pb in the second stage regenerator should be 3:2 and 2:3 respectively for the best performance. Further, systems with HoCu2 performed better than those with Er3Ni. The theoretical analysis of the system has been carried out using a simple isothermal model. The experimentally measured cooling powers are in good agreement with the theoretical predictions.

The proposed gun laws are not enough

Argues that as a more effective precuationary measure, it would seem that the firearms revocation threshold should be substantially lowered, or at least further clarified in guidance. Response to public debate in light of school shootings.

Investigations of a two-stage pulse tube cryocooler operating down to 2.5K

A two-stage pulse tube cryocooler (PTC) which produces a no-load temperature of similar to 2.5 K in its second stage at an operating frequency of 1.6 Hz has been designed and fabricated. The second stage of the system provides a refrigeration power of similar to 250 mW at 5.0 K. The system uses stainless steel meshes (mesh size 200) along with lead (Pb) granules and combinations of Pb, Er3Ni, and HoCu2 as the first and second stage regenerator materials, respectively. Experimental studies have been carried out on different pulse tube configurations by varying the dimensions of the pulse tubes and regenerators to arrive at the best one, which leads to the lowest no-load second stage cold head temperature. Using this configuration, detailed experimental studies have been conducted by varying the volume percentage ratios of the second stage regenerator materials such as HoCu2, Er3Ni, and Pb (with an average grain size of similar to 250 mu m). This article presents the results of our experimental studies on cryocoolers with the regenerator material arranged in layered structures. Comparative studies have also been presented for specific cases where the regenerator materials are arranged as a homogeneous mixture in the second stage. The experimental results clearly indicate that the design of PTCs should use only layered structures of regenerator materials and not homogenous mixtures.

Reaction of normal and pseudo 2-formylbenzenesulfonyl chlorides with amines:experimental and theoretical studies on the structure of 2-formyl benzenesulfonamides in solid, solution and gas phases

The reaction of 2-formylbenzenesulfonyl chloride 1 and its pseudo isomer 2 with primary amines give either the corresponding sulfonamido Schiff bases or the corresponding 2-formylbenzenesulfonamide depending on the concentration of the amine used. The derivatives exist as an equilibrium mixture of the corresponding sulfonamide and 2-alkyl-3-hydroxy(or 3-aminoalkyl)-benzisothiazole-1,1-dioxide. Spectroscopic studies suggest that 2-formylbenzenesulfonamides exist as benzisothiazole-1,1-dioxides in the solid state, as a mixture of 2-formylbenzenesulfonamide and the corresponding benzisothiazole-1,1-dioxide in solution and as 2-formyl-benzenesulfonamides in the gas phase.