{Tc(NO)(Cp)(PPh3)}+ – a novel technetium(I) core

Reactions between [TcI(NO)X2(PPh3)2(CH3CN)] complexes (X = Cl, Br) and KCp form the pseudotetrahedral organotechnetium compounds [TcI(NO)(Cp)(PPh3)X]. The halide ligands can readily be replaced by other halides or organometallic ligands giving access to a novel family of technetium(I) compounds with the robust {Tc(NO)(Cp)(PPh3)}+ core

2,6-Dipicolinoylbis(N,N-dialkylthioureas) as versatile building blocks for oligo- and polynuclear architectures

Similar reactions of 2,6-dipicolinoylbis(N,N-diethylthiourea) (H2La) with: (i) Ni(NO3)2·6H2O, (ii) a mixture of Ni(NO3)2·6H2O and AgNO3, (iii) a mixture of Ni(OAc)2·4H2O and PrCl3·7H2O and (iv) a mixture of Ni(OAc)2·4H2O and BaCl2·2H2O give the binuclear complex [Ni2(La)2(MeOH)(H2O)], the polymeric compound [NiAg2(La)2]∞, and the heterobimetallic complexes [Ni2Pr(La)2(OAc)3] and [Ni2Ba(La)3], respectively. The obtained assemblies can be used for the build up of supramolecular polymers by means of weak and medium intermolecular interactions. Two prototype examples of such compounds, which are derived from the trinuclear complexes of the types [MII2LnIII(L)2(OAc)3] and [MII2Ba(L)3], are described with the compounds {[CuII2DyIII(La)2(p-O2C-C6H4-CO2)(MeOH)4]Cl}∞ and [MnII2Ba(MeOH)(Lb)3]∞, H2Lb = 2,6-dipicolinoylbis(N,N-morpholinoylthiourea)

Expression of Class II Cytokine Genes in Children’s Skin

Immune regulation of the skin plays an important role in susceptibility and development of illnesses. The aim of our study was to localise the interleukin (IL)-10 family of cytokines, in children’s skin and to determine possible age-related differences in the expression level. The mRNA expression level of IL10, IL19, IL20, IL22, IL24, IL26, IL28B, IL29 and their receptors IL10RA, IL10RB, IL20RA, IL20RB, IL22RA1, IL22RA2, IL28RA was compared in skin biopsies of children and adults and in childrens’ skin cells by quantitative real-time PCR (qRT-PCR). Immunohistochemistry was performed to confirm the qRT-PCR findings. We found age-related differences in the expression of IL10RB, IL20, IL20RA, IL22RA1, IL22RA2, IL26 and IL28RA genes. Cell type-dependent expression of IL10 family cytokines was apparent in the skin. In addition to previously known differences in systemic immunological response of adults and children, the present results reveal differences in immune profile of adult and juvenile skin

Interaction of the quantized electromagnetic field with atoms in the presence of dispersing and absorbing dielectric bodies

A general theory of the interaction of the quantized electromagnetic field with atoms in the presence of dispersing and absorbing dielectric bodies of given Kramers--Kronig consistent permittivities is developed. It is based on a source-quantity representation of the electromagnetic field, in which the electromagnetic-field operators are expressed in terms of a continuous set of fundamental bosonic fields via the Green tensor of the classical problem. Introducing scalar and vector potentials, the formalism is extended in order to include in the theory the interaction of the quantized electromagnetic field with additional atoms. Both the minimal-coupling scheme and the multipolar-coupling scheme are considered. The theory replaces the standard concept of mode decomposition which fails for complex permittivities. It enables us to treat the effects of dispersion and absorption in a consistent way and to give a unified approach to the atom-field interaction, without any restriction to a particular interaction regime in a particular frequency range. All relevant information about the dielectric bodies such as form and intrinsic dispersion and absorption is contained in the Green tensor. The application of the theory to the spontaneous decay of an excited atom in the presence of dispersing and absorbing bodies is addressed.Comment: Paper presented at the International Conference on Quantum Optics and VIII Seminar on Quantum Optics, Raubichi, Belarus, May 28-31, 2000, 14 pages, LaTeX2e, no figure

Return to Hanging Rock: Lost Children in a Gothic Landscape

Using the philosophical position of phenomenology this article examines the ways in which ideas of wildness combine with Australian Gothic tropes such as the white colonial lost child and the bush as a haunted locale to compose key features of an Australian Ecogothic. Joan Lindsay’s enigmatic novel Picnic at Hanging Rock (1967) has prompted scholars such as Lesley Kathryn Hawkes to describe how in Australian literature for both adults and children ‘the environment is far more than a setting or backdrop against which the plot takes place’ (Hawkes, 2011,67). On St Valentine’s Day in 1900 three young Australian girls and their teacher disappear from a school picnic at the ancient site of Mount Macedon in Victoria. The analysis, which focuses on Lindsay’s posthumously published chapter eighteen (1987) examines how elements of the material, sensing world combine with the mythological or sacred to connect the human protagonists with the gothic landscape they inhabit. The resulting intersubjectivity problematizes colonial ideology and unsettles notions of national identity. Using the philosophical position of phenomenology this article examines the ways in which ideas of wildness combine with Australian Gothic tropes such as the white colonial lost child and the bush as a haunted locale to compose key features of an Australian Ecogothic. Joan Lindsay’s enigmatic novel Picnic at Hanging Rock (1967) has prompted scholars such as Lesley Kathryn Hawkes to describe how in Australian literature for both adults and children ‘the environment is far more than a setting or backdrop against which the plot takes place’ (Hawkes, 2011,67). On St Valentine’s Day in 1900 three young Australian girls and their teacher disappear from a school picnic at the ancient site of Mount Macedon in Victoria. The analysis, which focuses on Lindsay’s posthumously published chapter eighteen (1987) examines how elements of the material, sensing world combine with the mythological or sacred to connect the human protagonists with the gothic landscape they inhabit. The resulting intersubjectivity problematizes colonial ideology and unsettles notions of national identity

Three-dimensional quantization of the electromagnetic field in dispersive and absorbing inhomogeneous dielectrics

A quantization scheme for the phenomenological Maxwell theory of the full electromagnetic field in an inhomogeneous three-dimensional, dispersive and absorbing dielectric medium is developed. The classical Maxwell equations with spatially varying and Kramers-Kronig consistent permittivity are regarded as operator-valued field equations, introducing additional current- and charge-density operator fields in order to take into account the noise associated with the dissipation in the medium. It is shown that the equal-time commutation relations between the fundamental electromagnetic fields $\hat E$ and $\hat B$ and the potentials $\hat A$ and $\hat \phi$ in the Coulomb gauge can be expressed in terms of the Green tensor of the classical problem. From the Green tensors for bulk material and an inhomogeneous medium consisting of two bulk dielectrics with a common planar interface it is explicitly proven that the well-known equal-time commutation relations of QED are preserved

Ankyrin-mediated self-protection during cell invasion by the bacterial predator Bdellovibrio bacteriovorus

Predatory Bdellovibrio bacteriovorus are natural antimicrobial organisms, killing other bacteria by whole-cell invasion. Self-protection against prey-metabolizing enzymes is important for the evolution of predation. Initial prey entry involves the predator’s peptidoglycan DD-endopeptidases, which decrosslink cell walls and prevent wasteful entry by a second predator. Here we identify and characterize a self-protection protein from B. bacteriovorus, Bd3460, which displays an ankyrin-based fold common to intracellular pathogens of eukaryotes. Co-crystal structures reveal Bd3460 complexation of dual targets, binding a conserved epitope of each of the Bd3459 and Bd0816 endopeptidases. Complexation inhibits endopeptidase activity and cell wall decrosslinking in vitro. Self-protection is vital — DBd3460 Bdellovibrio deleteriously decrosslink self-peptidoglycan upon invasion, adopt a round morpholog, and lose predatory capacity and cellular integrity. Our analysis provides the first mechanistic examination of self-protection in Bdellovibrio, documents protection-multiplicity for products of two different genomic loci, and reveals an important evolutionary adaptation to an invasive predatory bacterial lifestyle

High-resolution aerosol concentration data from the Greenland NorthGRIP and NEEM deep ice cores

Records of chemical impurities from ice cores enable us to reconstruct the past deposition of aerosols onto polar ice sheets and alpine glaciers. Through this they allow us to gain insight into changes of the source, transport and deposition processes that ultimately determine the deposition flux at the coring location. However, the low concentrations of the aerosol species in the ice and the resulting high risk of contamination pose a formidable analytical challenge, especially if long, continuous and highly resolved records are needed. Continuous flow analysis, CFA, the continuous melting, decontamination and analysis of ice-core samples has mostly overcome this issue and has quickly become the de facto standard to obtain high-resolution aerosol records from ice cores after its inception at the University of Bern in the mid-1990s. Here, we present continuous records of calcium (Ca2+), sodium (Na+), ammonium (NH+4), nitrate (NO-3) and electrolytic conductivity at 1 mm depth resolution from the NGRIP (North Greenland Ice Core Project) and NEEM (North Greenland Eemian Ice Drilling) ice cores produced by the Bern Continuous Flow Analysis group in the years 2000 to 2011 (Erhardt et al., 2021). Both of the records were previously used in a number of studies but were never published in full 1 mm resolution. Alongside the 1 mm datasets we provide decadal averages, a detailed description of the methods, relevant references, an assessment of the quality of the data and its usable resolution. Along the way we will also give some historical context on the development of the Bern CFA system. The data is available in full 1 mm and 10-year-averaged resolution on PANGAEA (https://doi.org/10.1594/PANGAEA.935838, Erhardt et al., 2021