A focal plane detector design for a wide-band Laue-lens telescope

The energy range above 60 keV is important for the study of many open problems in high energy astrophysics such as the role of Inverse Compton with respect to synchrotron or thermal processes in GRBs, non thermal mechanisms in SNR, the study of the high energy cut-offs in AGN spectra, and the detection of nuclear and annihilation lines. Recently the development of high energy Laue lenses with broad energy bandpasses from 60 to 600 keV have been proposed for a Hard X ray focusing Telescope (HAXTEL) in order to study the X-ray continuum of celestial sources. The required focal plane detector should have high detection efficiency over the entire operative range, a spatial resolution of about 1 mm, an energy resolution of a few keV at 500 keV and a sensitivity to linear polarization. We describe a possible configuration of the focal plane detector based on several CdTe/CZT pixelated layers stacked together to achieve the required detection efficiency at high energy. Each layer can operate both as a separate position sensitive detector and polarimeter or work with other layers to increase the overall photopeak efficiency. Each layer has a hexagonal shape in order to minimize the detector surface required to cover the lens field of view. The pixels would have the same geometry so as to provide the best coupling with the lens point spread function and to increase the symmetry for polarimetric studies.Comment: 10 pages, 9 figure

Saturation of an Intra-Gene Pool Linkage Map: Towards a Unified Consensus Linkage Map for Fine Mapping and Synteny Analysis in Common Bean

Map-based cloning and fine mapping to find genes of interest and marker assisted selection (MAS) requires good genetic maps with reproducible markers. In this study, we saturated the linkage map of the intra-gene pool population of common bean DOR364×BAT477 (DB) by evaluating 2,706 molecular markers including SSR, SNP, and gene-based markers. On average the polymorphism rate was 7.7% due to the narrow genetic base between the parents. The DB linkage map consisted of 291 markers with a total map length of 1,788 cM. A consensus map was built using the core mapping populations derived from inter-gene pool crosses: DOR364×G19833 (DG) and BAT93×JALO EEP558 (BJ). The consensus map consisted of a total of 1,010 markers mapped, with a total map length of 2,041 cM across 11 linkage groups. On average, each linkage group on the consensus map contained 91 markers of which 83% were single copy markers. Finally, a synteny analysis was carried out using our highly saturated consensus maps compared with the soybean pseudo-chromosome assembly. A total of 772 marker sequences were compared with the soybean genome. A total of 44 syntenic blocks were identified. The linkage group Pv6 presented the most diverse pattern of synteny with seven syntenic blocks, and Pv9 showed the most consistent relations with soybean with just two syntenic blocks. Additionally, a co-linear analysis using common bean transcript map information against soybean coding sequences (CDS) revealed the relationship with 787 soybean genes. The common bean consensus map has allowed us to map a larger number of markers, to obtain a more complete coverage of the common bean genome. Our results, combined with synteny relationships provide tools to increase marker density in selected genomic regions to identify closely linked polymorphic markers for indirect selection, fine mapping or for positional cloning

HIV Antigen Incorporation within Adenovirus Hexon Hypervariable 2 for a Novel HIV Vaccine Approach

Adenoviral (Ad) vectors have been used for a variety of vaccine applications including cancer and infectious diseases. Traditionally, Ad-based vaccines are designed to express antigens through transgene expression of a given antigen. However, in some cases these conventional Ad-based vaccines have had sub-optimal clinical results. These sub-optimal results are attributed in part to pre-existing Ad serotype 5 (Ad5) immunity. In order to circumvent the need for antigen expression via transgene incorporation, the “antigen capsid-incorporation” strategy has been developed and used for Ad-based vaccine development in the context of a few diseases. This strategy embodies the incorporation of antigenic peptides within the capsid structure of viral vectors. The major capsid protein hexon has been utilized for these capsid incorporation strategies due to hexon's natural role in the generation of anti-Ad immune response and its numerical representation within the Ad virion. Using this strategy, we have developed the means to incorporate heterologous peptide epitopes specifically within the major surface-exposed domains of the Ad capsid protein hexon. Our study herein focuses on generation of multivalent vaccine vectors presenting HIV antigens within the Ad capsid protein hexon, as well as expressing an HIV antigen as a transgene. These novel vectors utilize HVR2 as an incorporation site for a twenty-four amino acid region of the HIV membrane proximal ectodomain region (MPER), derived from HIV glycoprotein gp41 (gp41). Our study herein illustrates that our multivalent anti-HIV vectors elicit a cellular anti-HIV response. Furthermore, vaccinations with these vectors, which present HIV antigens at HVR2, elicit a HIV epitope-specific humoral immune response

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Synthesis and properties of the heterospin (S1 = S2 = 1/2) radical-ion salt bis(mesitylene)molybdenum(I) [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl

The authors are grateful to the Presidium of the Russian Academy of Sciences (Project 8.14), the Royal Society (RS International Joint Project 2010/R3), the Leverhulme Trust (Project IN-2012-094), the Siberian Branch of the Russian Academy of Sciences (Project 13), the Ministry of Education and Science of the Russian Federation (Project of Joint Laboratories of Siberian Branch of the Russian Academy of Sciences and National Research Universities), and the Russian Foundation for Basic Research (Projects 13-03-00072 and 15-03-03242) for financial support of various parts of this work. N.A.S. thanks the Council for Grants of the President of Russian Federation for postdoctoral scholarship (grant MK-4411.2015.3). B.E.B. is grateful for an EaStCHEM Hirst Academic Fellowship. A.V.Z. thanks the Foundation named after D. I. Mendeleev, Tomsk State University, for support of his work.Low-temperature interaction of [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (1) with MoMes2 (Mes = mesitylene / 1,3,5-trimethylbenzene) in tetrahydrofuran gave the heterospin (S1 = S2 = 1/2) radical-ion salt [MoMes2]+[1]– (2) whose structure was confirmed by single-crystal X-ray diffraction (XRD). The structure revealed alternating layers of the cations and anions with the Mes ligands perpendicular, and the anions tilted by 45°, to the layer plane. At 300 K the effective magnetic moment of 2 is equal to 2.40 μB (theoretically expected 2.45 μB) and monotonically decreases with lowering of the temperature. In the temperature range 2−300 K, the molar magnetic susceptibility of 2 is well-described by the Curie-Weiss law with parameters C and θ equal to 0.78 cm3⋅K⋅mol–1 and −31.2 K, respectively. Overall, the magnetic behavior of 2 is similar to that of [CrTol2]+[1]– and [CrCp*2]+[1]–, i.e. changing the cation [MAr2]+ 3d atom M = Cr (Z = 24) with weak spin-orbit coupling (SOC) to a 4d atom M = Mo (Z = 42) with stronger SOC does not affect macroscopic magnetic properties of the salts. For the XRD structure of salt 2, parameters of the Heisenberg spin-Hamiltonian were calculated using the broken-symmetry DFT and CASSCF approaches, and the complex 3D magnetic structure with both the ferromagnetic (FM) and antiferromagnetic (AF) exchange interactions was revealed with the latter as dominating. Salt 2 is thermally unstable and slowly loses the Mes ligands upon storage at ambient temperature. Under the same reaction conditions, interaction of 1 with MoTol2 (Tol = toluene) proceeded with partial loss of the Tol ligands to afford diamagnetic product.PostprintPostprintPeer reviewe

The Preparation, Characterization, and X-Ray Structural Analysis of Dichlorobis[1-methyl-3-(2-propyl)-2(3H)-imidazolethione]mercury(II)

A new compd. of Hg(II) chloride complexed to 1-methyl-3-(2-propyl)-2(3H)-imidazolethione (mipit) was prepd. and characterized via std. methods and x-ray crystallog. The structural significance of this study is that it shows one of the few monomeric examples of a Hg(II) chloride thione complex reported to date. The compd. crystallizes in space group P21/c with a 17.143(6), b 17.047(6), c 14.759(5) Å, β 105.899(5)°, Z = 8. The coordination sphere is distorted tetrahedral with Hg-S bonds and Hg-Cl bond distances falling within the normally expected ranges. Bond angles ranged from 108.11(4)° to 115.51(4)° with the widest angle being obsd. for the S-Hg-S linkage. Ligand bond distances and angles including the C=S distance are within the normally expected values obsd. for this compd

CCDC 279926: Experimental Crystal Structure Determination

Related Article: D.J.Williams, A.M.Hutchings, N.E.McConnell, R.A.Faucher, B.E.Huck, C.A.S.Brevett, D.VanDerveer|2006|Inorg.Chim.Acta|359|2252|doi:10.1016/j.ica.2005.12.074,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

Main Group Metal halide Complexes with Sterically Hindered Thioureas Part XVIII: The Synthesis, Characterization, and X-Ray Crystallographic Study of a BiCl3 Complex with 1-methyl-2(3H)-imidazolethione

A new Bi(III) chloride complex with 1- methyl-2(3H)-imidazolethione (meimtH) was synthesized and characterized via std. methods including solid state 13C NMR and single crystal x-ray diffractometry. The complex, BiCl3[meimtH]2.5·H2O, crystallizes in a triclinic space group. The complex has two different coordination spheres for Bi, which are linked together in the solid state via H bonding. One coordination sphere BiCl3(meimtH)3, is distorted octahedral with the ligands in meridional positions, while the other [BiCl3(meimtH)2]2 is a dimer consisting of two octahedra sharing a common edge through bridging Cl atoms. The ligands are cis to each other and trans to the Cl bridges, while the remaining four Cl atoms are trans to each other and perpendicular to the Cl-S plane. There is no strong evidence for a stereoactive lone pair in either coordination sphere