3-Meth­oxy-4-methyl-1H-1,2,4-triazol-5(4H)-one monohydrate

In the title hydrate, C4H7N3O2·H2O, all the non-H atoms lie on a crystallographic mirror plane. The H atoms of both methyl groups are disordered over two sets of sites. In the crystal, N—H⋯Ow and Ow—H⋯Ok (w = water and k = ketone) hydrogen bonds link the components into (010) sheets

{6-[2,5-Bis(chloro­meth­yl)-3,4-dihydroxy­tetra­hydro­furan-2-yl­oxy]-3-chloro-4,5-dihydr­oxy-3,4,5,6-tetra­hydro-2H-pyran-2-yl}methyl acetate dihydrate

The title compound, C14H21Cl3O9·2H2O, is a disaccharide constructed from a galactose and a fructose. In the mol­ecular structure, the tetra­hydro­furan five-membered ring and tetra­hydro­pyran six-membered ring assume envelope and chair conformations, respectively. An extensive O—H⋯O hydrogen-bonding network occurs in the crystal structure

2,2′-(Piperazine-1,4-di­yl)diacetonitrile

The complete mol­ecule of the title compound, C8H12N4, is generated by a crystallographic inversion centre. The piperazine ring adopts a chair conformation with the N-bonded substituents in equatorial positions. In the crystal, mol­ecules are linked by C—H⋯Nc (c = cyanide) hydrogen bonds

Polytypism and Unexpected Strong Interlayer Coupling of two-Dimensional Layered ReS2

The anisotropic two-dimensional (2D) van der Waals (vdW) layered materials, with both scientific interest and potential application, have one more dimension to tune the properties than the isotropic 2D materials. The interlayer vdW coupling determines the properties of 2D multi-layer materials by varying stacking orders. As an important representative anisotropic 2D materials, multilayer rhenium disulfide (ReS2) was expected to be random stacking and lack of interlayer coupling. Here, we demonstrate two stable stacking orders (aa and a-b) of N layer (NL, N>1) ReS2 from ultralow-frequency and high-frequency Raman spectroscopy, photoluminescence spectroscopy and first-principles density functional theory calculation. Two interlayer shear modes are observed in aa-stacked NL-ReS2 while only one interlayer shear mode appears in a-b-stacked NL-ReS2, suggesting anisotropic-like and isotropic-like stacking orders in aa- and a-b-stacked NL-ReS2, respectively. The frequency of the interlayer shear and breathing modes reveals unexpected strong interlayer coupling in aa- and a-b-NL-ReS2, the force constants of which are 55-90% to those of multilayer MoS2. The observation of strong interlayer coupling and polytypism in multi-layer ReS2 stimulate future studies on the structure, electronic and optical properties of other 2D anisotropic materials

AGROBEST: an efficient Agrobacterium-mediated transient expression method for versatile gene function analyses in Arabidopsis seedlings

Background: Transient gene expression via Agrobacterium-mediated DNA transfer offers a simple and fast method to analyze transgene functions. Although Arabidopsis is the most-studied model plant with powerful genetic and genomic resources, achieving highly efficient and consistent transient expression for gene function analysis in Arabidopsis remains challenging. Results: We developed a highly efficient and robust Agrobacterium-mediated transient expression system, named AGROBEST (Agrobacterium-mediated enhanced seedling transformation), which achieves versatile analysis of diverse gene functions in intact Arabidopsis seedlings. Using β-glucuronidase (GUS) as a reporter for Agrobacterium-mediated transformation assay, we show that the use of a specific disarmed Agrobacterium strain with vir gene pre-induction resulted in homogenous GUS staining in cotyledons of young Arabidopsis seedlings. Optimization with AB salts in plant culture medium buffered with acidic pH 5.5 during Agrobacterium infection greatly enhanced the transient expression levels, which were significantly higher than with two existing methods. Importantly, the optimized method conferred 100% infected seedlings with highly increased transient expression in shoots and also transformation events in roots of ~70% infected seedlings in both the immune receptor mutant efr-1 and wild-type Col-0 seedlings. Finally, we demonstrated the versatile applicability of the method for examining transcription factor action and circadian reporter-gene regulation as well as protein subcellular localization and protein–protein interactions in physiological contexts. Conclusions: AGROBEST is a simple, fast, reliable, and robust transient expression system enabling high transient expression and transformation efficiency in Arabidopsis seedlings. Demonstration of the proof-of-concept experiments elevates the transient expression technology to the level of functional studies in Arabidopsis seedlings in addition to previous applications in fluorescent protein localization and protein–protein interaction studies. In addition, AGROBEST offers a new way to dissect the molecular mechanisms involved in Agrobacterium-mediated DNA transfer

(2-{[1-(Pyridin-2-yl)ethyl­idene]amino­meth­yl}pyridine-κ3 N,N′,N′′)bis­(thio­cyanato-κN)zinc

The complete mol­ecule of the title mononuclear zinc(II) complex, [Zn(NCS)2(C13H13N3)], is generated by crystallographic twofold symmetry, with the metal atom lying on the rotation axis. The pendant methyl group of the ligand is statistically disordered over two sites. The Zn2+ cation is coordinated by the N,N′,N′′-tridentate Schiff base ligand, and by two thio­cyanate N atoms, forming a distorted ZnN5 trigonal–bipyramidal geometry

Atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer

The wavefunction of massless Dirac fermions is a two-component spinor. In graphene, a one-atom-thick film showing two-dimensional Dirac-like electronic excitations, the two-component representation reflects the amplitude of the electron wavefunction on the A and B sublattices. This unique property provides unprecedented opportunities to image the two components of massless Dirac fermions spatially. Here we report atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer by scanning tunnelling microscopy and spectroscopy. A gap of about 20 meV, driven by inversion symmetry breaking by the substrate potential, is observed in the graphene on both SiC and graphite substrates. Such a gap splits the n = 0 Landau level (LL) into two levels, 0+ and 0-. We demonstrate that the amplitude of the wavefunction of the 0- LL is mainly at the A sites and that of the 0+ LL is mainly at the B sites of graphene, characterizing the internal structure of the spinor of the n = 0 LL. This provides direct evidence of the two-component nature of massless Dirac fermions.Comment: 4 Figures in main text and 4 Figures in S