Hollow Gaussian Schell-model beam and its propagation

In this paper, we present a new model, hollow Gaussian-Schell model beams (HGSMBs), to describe the practical dark hollow beams. An analytical propagation formula for HGSMBs passing through a paraxial first-order optical system is derived based on the theory of coherence. Based on the derived formula, an application example showing the influence of spatial coherence on the propagation of beams is illustrated. It is found that the beam propagating properties of HGSMBs will be greatly affected by their spatial coherence. Our model provides a very convenient way for analyzing the propagation properties of partially coherent dark hollow beams.Comment: 13pages, 2 figure

Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation

Rapid synthesis of 4-ethyloctanoic acid by means of microwave irradiation is described. Diethyl malonate reacted with 2-ethyl-1-bromohexane in the presence of sodium ethoxide to give diethyl (2-ethylhexyl)malonate (1b). 1b was saponified in the solution of ethanol and potassium hydroxide and then acidified to form (2-ethylhexyl)propanedioic acid (1c), and 1c was heated and decarboxylized to give 4-ethyloctanoic acid (1d). The influence of reaction temperature and reaction time on the yield of 1b and the effect of reaction time on the yield of 1c and 1d were investigated in order to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 1b were a mole ratio of sodium to diethyl malonate to 2-ethylhexyl bromide of 0.1:0.11:0.11, a reaction temperature of 80–85 °C, and a reaction time of 2–2.5 h. The yield of 1b was about 79%. 1b was saponified for 30 min and then acidified to form 1c, and the yield of 1c was 96%. 1c was heated for 16 min at 180°C to give 1d, and the yield of 1d was about 90%. The overall yield of 1d is 70% under microwave irradiation. The reaction time was reduced greatly. In order to compare the result of microwave irradiation with that of an oil bath, the reactions were also performed in an oil bath. The structures of intermediates, product and by-product were confirmed by HRMS, 1H NMR, 13C-NMR and IR

Transitional fossils illuminate early evolution of the ant-like stone beetle tribe Leptomastacini (Coleoptera: Staphylinidae: Scydmaeninae)

The ant-like stone beetle supertribe Mastigitae (Staphylinidae: Scydmaeninae) comprises nine extant and five extinct genera that exhibit unusual morphological specializations and ecological adaptions. Recent discoveries of mastigite fossils from Upper Cretaceous–middle Eocene deposits have significantly improved our knowledge of the evolutionary history of this group, yet a direct fossil record for two modern tribes of unclear affinities, i.e. Leptomastacini and Papusini, is lacking. Herein we describe a new genus and species, †Archemastax divida gen. et sp. nov., based on two well-preserved individuals entombed in mid-Cretaceous Burmese amber (c. 99 Ma), representing the earliest known representative of Leptomastacini. †Archemastax possesses both plesiomorphic and derived characters, with a few important traits shared with extant members of Papusini and Clidicini. A data set of 70 morphological characters scored for 29 species of Mastigitae was analysed using maximum parsimony and Bayesian inference; both analyses recovered a sister relationship between †Archemastax and extant leptomastacines. However, in the former analysis Leptomastacini was recovered as sister to the remaining Mastigitae, while the latter indicated an origin of Leptomastacini from within Clidicini. Although a close affinity between †Archemastax and Papusini was not supported by our analyses, similarities in some shared characters of these two groups are discussed. http://zoobank.org/urn:lsid:zoobank.org:pub:BB17DF86-25FC-48B5-8AFB-1DB27328280F.</p

(E)-N′-(3,4-Dimethoxy­benzyl­idene)-2,4-dihydroxy­benzohydrazide methanol solvate

The title compound, C16H16N2O5·CH3OH, was obtained from a condensation reaction of 3,4-dimethoxy­benzaldehyde and 2,4-dihydroxy­benzohydrazide. The non-H atoms of the Schiff base mol­ecule are approximately coplanar (r.m.s. deviation = 0.043 Å) and the dihedral angle between the two benzene rings is 1.6 (1)°. The mol­ecule adopts an E configuration with respect to the C=N double bond. An intra­molecular O—H⋯O hydrogen bond is observed. The Schiff base and methanol mol­ecules are linked into a two-dimensional network parallel to (10) by inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds

SYNTHESIS OF CYCLOBUTANE ANALOGUES

2-(3-Acetyl-2,2-dimethylcyclobutyl)acetic acid (pinonic acid) was synthesized using &alpha;-pinene as raw material and potassium permanganate as oxidant. This compound reacted with substituted aniline to produce eight kinds of derivatives with cyclobutane moiety. The yields of the cyclobutane analogues ranged from 24.9 to 78.2 %. KEY WORDS: Cyclobutane analogues, Pinonic acid, Oxidation Bull. Chem. Soc. Ethiop. 2009, 23(1), 135-139

Bis(2,2′-bipyridine-κ2 N,N′)(3,5-dinitro-2-oxidobenzoato-κ2 O 1,O 2)cobalt(II)

In the title compound, [Co(C7H2N2O7)(C10H8N2)2], the CoII atom is coordinated by four N atoms from two 2,2′-bipyridine ligands and two O atoms from a 3,5-dinitro-2-oxidobenzoate ligand, displaying a distorted octa­hedral coordination geometry. The crystal structure involves C—H⋯O hydrogen bonds between the 2,2′-bipyridine ligands and the carboxyl­ate and NO2 groups of the 3,5-dinitro-2-oxidobenzoate ligand

Development and validation of an ELISA using a protein encoded by ORF2 antigenic domain of porcine circovirus type 2

<p>Abstract</p> <p>Background</p> <p>The capsid protein (ORF2) is a major structural protein of porcine circovirus type 2 (PCV2). A simple and reliable diagnostic method based on ORF2 protein immunoreactivity would serve as a valuable diagnostic method for detecting serum antibodies to PCV2 and monitoring PCV infection. Here, we reported an indirect enzyme-linked immunosorbent assay (I-ELISA) by using an antigenic domain (113-147AA) of ORF2-encoded antigen, expressed in <it>E. coli</it>, for diagnosis of PCV infection.</p> <p>Results</p> <p>The ELISA was performed on 288 serum samples collected from different porcine herds and compared with an indirect immunofluorescent assay (IFA). In total, 262 of 288 samples were positive as indicated by both I-ELISA and IFA. The specificity and sensitivity of I-ELISA were 87.7% and 93.57%.</p> <p>Conclusions</p> <p>This ELISA is suitable for detection and discrimination of PCV2 infection in both SPF and farm antisera.</p

Boolean Game on Scale-free Networks

Inspired by the local minority game, we propose a network Boolean game and investigate its dynamical properties on scale-free networks. The system can self-organize to a stable state with better performance than random choice game, although only the local information is available to the agent. By introducing the heterogeneity of local interactions, we find the system has the best performance when each agent's interaction frequency is linear correlated with its information capacity. Generally, the agents with more information gain more than those with less information, while in the optimal case, each agent almost has the same average profit. In addition, we investigate the role of irrational factor and find an interesting symmetrical behavior.Comment: 12 pages and 6 figure

Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1

Background: AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo. Methods and Findings: The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo. Conclusions: These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting. © 2007 Tsuzuki et al

Inhibition of Quorum Sensing-Controlled Virulence Factor Production in Pseudomonas aeruginosa PAO1 by Ayurveda Spice Clove (Syzygium Aromaticum) Bud Extract

Quorum sensing controls the virulence determinants in most proteobacteria. In this work, the hexane, chloroform and methanol extracts of an Ayurveda spice, namely clove (Syzygium aromaticum), shown anti-quorum sensing activity. Hexane and methanol extracts of clove inhibited the response of C. violaceum CV026 to exogenously supplied N‐hexanoylhomoserine lactone, in turn preventing violacein production. Chloroform and methanol extracts of clove significantly reduced bioluminescence production by E. coli [pSB1075] grown in the presence of N-(3-oxododecanoyl)-l-homoserine lactone. We demonstrated that clove extract inhibited quorum sensing-regulated phenotypes in Pseudomonas aeruginosa PA01, including expression of lecA::lux (by hexane extract), swarming (maximum inhibition by methanol extract), pyocyanin (maximum inhibition by hexane extract). This study shows that the presence of natural compounds that exhibit anti-quorum sensing activity in the clove extracts may be useful as the lead of anti-infective drugs