1,680 research outputs found
Synthesis and Characterization of platinum â selenium Derivatives: X-ray Structure of \u3cem\u3etrans\u3c/em\u3e-Pt(Pet\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e(SePh)\u3csub\u3e2\u3c/sub\u3e
The crystal structure of trans-[((bis)triethylphosphine)(bis(phenylselenato))platinum (II)] has been determined by single crystal X-ray diffraction. Crystallization occurs in the triclinic space group P-1 (No. 2) with a = 8.9964(2) Ă
, b = 11.5103(2) Ă
, c = 14.9335(3) Ă
; α = 85.8750(10)°, ÎČ = 72.5350(10)°, Îł = 68.4450(10)°. Details of the structure and spectroscopic results are presented and discussed and comparisons are made with related square planar platinum (II) structures
\u3cem\u3eN\u3c/em\u3e-Methylbenzothiazole-2(3\u3cem\u3eH\u3c/em\u3e)-selone, C\u3csub\u3e8\u3c/sub\u3eH\u3csub\u3e7\u3c/sub\u3eNSSe
The crystal structure of N-methyl1,3-benzothiazole-2(3H)-selone, (mbts) has been studied to estimate the changes in the molecular geometry of the mbts ligand upon coordination. Hypervalent complexes of mbts with TeII and II have been studied by us previously. A significant elongation of the Se=C bond [from 1.817 (7) in mbts to 1.85-1.88 Ă
in the complexes] was found, but there were no significant changes in the other geometric parameters of the ligand. The only other bond-length decrease of note was for SeC-NMe [from 1.35 (1) in mbts to 1.32-1.34 Ă
in the complexes]. Thus, only the amino group takes part in electron redistribution upon coordination
Bromobis(Diethyldithiocarbamato)(4-Methoxyphenyl)Tellurium(IV)
The crystals of the TeIV complex p-CH3OC6H4Te(Et2NCS2)2Br are isomorphous with those of the the iodine and mixed iodine/bromine analogues previously investigated. The structure is pentagonal bipyramidal at the Te atom with four S atoms [Te-S 2.618-2.721 (1) Ă
] and the Br atom [Te-Br 2.943 (1) Ă
] in equatorial positions. The p-methoxyphenyl group is axial [Te-C 2.147 (3) Ă
]. The second axial position is approached by a Br atom of a centrosymmetrically related complex [TeBr 3.423 (1) Ă
, C-TeBr 173.1 (1)°] so that the molecules are joined into centrosymmetric pairs by this weak secondary coordination
Ăclairâa web service for unravelling species origin of sequences sampled from mixed host interfaces
The identification of the genes that participate at the biological interface of two species remains critical to our understanding of the mechanisms of disease resistance, disease susceptibility and symbiosis. The sequencing of complementary DNA (cDNA) libraries prepared from the biological interface between two organisms provides an inexpensive way to identify the novel genes that may be expressed as a cause or consequence of compatible or incompatible interactions. Sequence classification and annotation of species origin typically use an orthology-based approach and require access to large portions of either genome, or a close relative. Novel species- or clade-specific sequences may have no counterpart within existing databases and remain ambiguous features. Here we present a web-service, Ăclair, which utilizes support vector machines for the classification of the origin of expressed sequence tags stemming from mixed host cDNA libraries. In addition to providing an interface for the classification of sequences, users are presented with the opportunity to train a model to suit their preferred species pair. Ăclair is freely available at
Exact off-resonance near fields of small-size extended hemielliptic 2-D lenses illuminated by plane waves
The near fields of small-size extended hemielliptic lenses made of rexolite
and isotropic quartz and illuminated by E- and H-polarized plane waves are
studied. Variations in the focal domain size, shape, and location are presented
versus the angle of incidence of the incoming wave. The problem is solved
numerically in a two-dimensional formulation. The accuracy of results is
guaranteed by using a highly efficient numerical algorithm based on the
combination of the Muller boundary integral equations, the method of analytical
regularization, and the trigonometric Galerkin discretization scheme. The
analysis fully accounts for the finite size of the lens as well as its
curvature and thus can be considered as a reference solution for other
electromagnetic solvers. Moreover, the trusted description of the focusing
ability of a finite-size hemielliptic lens can be useful in the design of
antenna receivers.Comment: 7 pages, 7 figure
Matching Conditions in Atomistic-Continuum Modeling of Materials
A new class of matching condition between the atomistic and continuum regions
is presented for the multi-scale modeling of crystals. They ensure the accurate
passage of large scale information between the atomistic and continuum regions
and at the same time minimize the reflection of phonons at the interface. These
matching conditions can be made adaptive if we choose appropriate weight
functions. Applications to dislocation dynamics and friction between
two-dimensional atomically flat crystal surfaces are described.Comment: 6 pages, 4 figure
A large bioassay identifies Stb resistance genes that provide broad resistance against Septoria tritici blotch Disease in the UK
Septoria tritici blotch (STB) is one of the most damaging fungal diseases of wheat in Europe, largely due to the paucity of effective resistance genes against it in breeding materials. Currently dominant protection methods against this disease, e.g. fungicides and the disease resistance genes already deployed, are losing their effectiveness. Therefore, it is vital that other available disease resistance sources are identified, understood and deployed in a manner that maximises their effectiveness and durability. In this study, we assessed wheat genotypes containing nineteen known major STB resistance genes (Stb1 through to Stb19) or combinations thereof against a broad panel of 93 UK Zymoseptoria tritici isolates. Five infection symptom components (days post infection to the development of first symptoms and pycnidia, percentage coverage of the infected leaf area with chlorosis/necrosis and pycnidia and spore counts from spore wash) were measured and average disease levels calculated for each genotype. The different Stb genes were found to vary greatly in the levels of protection they provided, with no Z. tritici isolate found to be virulent against all tested resistance genes. Disease resistance controlled by different Stb genes was associated with different levels of chlorosis, with high levels of early chlorosis in some genotypes correlated with high resistance to fungal pycnidia development. Stb10, Stb11, Stb12, Stb16q, Stb17, and Stb19 were identified as contributing broad spectrum disease resistance, and synthetic hexaploid wheat lines were identified as particularly promising sources of broadly effective STB resistances. Wheat genotypes carrying multiple Stb genes were found to provide higher levels of resistance than expected given their historical levels of use. The knowledge obtained here will aid UK breeders in prioritising Stb genes for future breeding programmes. In addition, this study identified the most interesting Stb genes for cloning and detailed functional analysis
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