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This is an update of a previous review (Naumis et al 2017 Rep. Prog. Phys. 80 096501). Experimental and theoretical advances for straining graphene and other metallic, insulating, ferroelectric, ferroelastic, ferromagnetic and multiferroic 2D materials were considered. We surveyed (i) methods to induce valley and sublattice polarisation (P) in graphene, (ii) time-dependent strain and its impact on graphene's electronic properties, (iii) the role of local and global strain on superconductivity and other highly correlated and/or topological phases of graphene, (iv) inducing polarisation P on hexagonal boron nitride monolayers via strain, (v) modifying the optoelectronic properties of transition metal dichalcogenide monolayers through strain, (vi) ferroic 2D materials with intrinsic elastic (σ), electric (P) and magnetic (M) polarisation under strain, as well as incipient 2D multiferroics and (vii) moiré bilayers exhibiting flat electronic bands and exotic quantum phase diagrams, and other bilayer or few-layer systems exhibiting ferroic orders tunable by rotations and shear strain. The update features the experimental realisations of a tunable two-dimensional Quantum Spin Hall effect in germanene, of elemental 2D ferroelectric bismuth, and 2D multiferroic NiI2. The document was structured for a discussion of effects taking place in monolayers first, followed by discussions concerning bilayers and few-layers, and it represents an up-to-date overview of exciting and newest developments on the fast-paced field of 2D materials. [ABSTRACT FROM AUTHOR]

A study of FixJ, which is a response regulator of the two-component signal transduction pathway involved in the transcriptional activation of nitrogen fixation genes of sinorhizobium meliloti, is presented. The results are consistent with a scenario in which a transcriptionally active species of FixJ is a homodimer of the phosphorylated form.

Results demonstrate that Ile 209 and Ile210 participate in the signal transduction of the heme domain of Rhizobium meliloti FixL histidine kinase as shown by mutational analysis. Data suggest that regulation of the kinase activity is mediated by conformational changes of the amino acid residues following oxygen binding.

The immunoglobulin kappa gene 3' enhancer (E3') suppresses V(sub kappa)-J(sub kappa) recombination and restricts it to the pre-B developmental stage of B cells. The B/T specificity of V(sub kappa)-J(sub kappa) recombination is controled by the PU.1 binding domain in E3'. A mutation in the PU.1 domain causes recombination in both B and T cells. Deletion of E3' causes rearrangement of the kappa gene in the early pro-B stage of B cells.

The gene coding for the synthesis of symbionin in the aphid endosymbiont was sequenced and assessed for chaperonin functions. Sequence data from a 2,739 bp fragment indicated that the symbionin-coding region was bicistronic, and therefore designated as sym operon. The operon consisted of symL and symS genes, which by complementation analysis with gro-mutants of Escherichia coli, was shown to be analogous to E. coli chaperonins. Amino acid sequence comparisons confirmed this finding. The results suggest that symbionin is a molecular chaperone, and is involved in the assembly of polypeptides imported into the endosymbiont from the host cell.

The study describes the hydrogen bond structure of a key tyrosine (Tyr) residue in a flavin-binding blue light sensor TePixD from the commonly found cyanobacterium, Thermosynechoccus elongatus. The results show that the hydrogen bond in the structure becomes stronger when photoconversion to the light state is accompanied with a change in the H-bond angle.

The mutants of the heme distal Arg2000, Arg208, Ile209, Il2210 and Arg214 residues of Sinorhizobium meliloti (SM)FixL are characterized biochemically and physicochemically, as they are significant residues in ligand-linked kinase regulation. The comparison of the NMR data between the wild type and R214K and R214Q mutants have shown that a strong electrostatic interaction between residue 214 and the iron-bound ligand is not necessarily required for the single convergent structure and eventually for the downregulation of FixL.

Endoh, Hiroshi, Takaho Kaneko, Hiro Nakamura, Katsuhiko Doi, and Eiji Takahashi. Improved cardiac contractile functions in hypoxia-reoxygenation in rats treated with low concentration [Co.sup.2+]. Am J Physiol Heart Circ Physiol 279: H2713-H2719, 2000.--An intracellular mechanism that senses decreases in tissue oxygen level and stimulates hypoxia-related gene expression has been reported in various cell types including the cardiac cell. The mechanism can also be activated by [Co.sup.2+] in normoxia. Thus we investigated the effects of prior chronic oral Co[Cl.sub.2] on mechanical functions of isolated, perfused rat hearts in hypoxia-reoxygenation. In normoxic rats, 43 days of [Co.sup.2+] administration increased hematocrit from 45 [+ or -] 0.3% (control, n = 18) to 51 [+ or -] 0.6% (n = 19). In hypoxia and reoxygenation, [Co.sup.2+]-pretreated hearts exhibited a significantly higher rate-pressure product (267 and 163%, respectively) and coronary flow (127 and 118%, respectively) and lower end-diastolic pressure (72 and 60%, respectively) compared with the control hearts. Although the oral [Co.sup.2+] administration significantly raised myocardial [Co.sup.2+] concentration, it did not affect mitochondrial respiration, tissue glycogen concentration, or myocardial tissue histology. The levels of vascular endothelial growth factor, aldolase-A, and glucose transporter-1 mRNA were significantly elevated in the [Co.sup.2+]-treated myocardium. We conclude that cardiac contractile functions would gain hypoxic tolerance when the endogenous cellular oxygen-sensing mechanism is activated. energy metabolism; hypoxia-related genes; oxygen-sensing mechanism

The coordination structure of the heme iron of water-soluble Rhizobium meliloti FixL is described with resonance Raman as well as electron paramagnetic resonance and extended x-ray absorption fine structure spectroscopic techniques. Three structural features of the iron coordination structure for oxy- and deoxy-FixL* were observed, which were also exhibited in FixLN.

ChrA is a response regulator (RR) in the two-component system involved in regulating the degradation and transport of haem (Fe-porphyrin) in the pathogen Corynebacterium diphtheriae. Here, the crystal structure of full-length ChrA is described at a resolution of 1.8 Å. ChrA consists of an N-terminal regulatory domain, a long linker region and a C-terminal DNA-binding domain. A structural comparison of ChrA with other RRs revealed substantial differences in the relative orientation of the two domains and the conformation of the linker region. The structural flexibility of the linker could be an important feature in rearrangement of the domain orientation to create a dimerization interface to bind DNA during haem-sensing signal transduction. [ABSTRACT FROM AUTHOR]