Cyclometallated Platinum(II) Complexes Featuring an Unusual, C^N‐Coordinating Pyridyl‐pyridylidene Ligand and L X Coligands: Synthesis, Structures and Dual Luminescence Behavior

Thanks to an unusual protodemethylation reaction, a series of luminescent cyclometallated platinum(II) complexes can be prepared, which incorporate a rare NC-chelating, pyridyl-pyridylidene ligand, in combination with OO-coordinating acetylacetonate (acac) or NO-coordinating 2-picolinate (pic) or 8-hydroxyquinolate. The acac and pic complexes show unusual dual emission in a frozen glass.A series of cyclometallated platinum(II) complexes incorporating a rare, N^C-chelating, pyridyl-pyridylidene ligand are described, in which the coordination sphere is completed by two chlorides or an L X co-ligand, namely O O-coordinating acetylacetonate (acac), or N^O-coordinating 2-picolinate (pic) or 8-hydroxyquinolinate. The acac and pic complexes have been structurally characterized in the solid state by single-crystal X-ray diffraction. These two complexes display red phosphorescence in the solid state at room temperature. In a frozen glass at 77 K, all four complexes show two broad emission bands that span much of the visible spectrum, apparently from two unequilibrated excited states

A High-Resolution Combined Scanning Laser- and Widefield Polarizing Microscope for Imaging at Temperatures from 4 K to 300 K

Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as for example birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a $^4$He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via Faraday effect or imaging of structural features, such as twin-walls in tetragonal SrTiO$_3$. The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism and superconductivity.Comment: 14 pages, 11 figures. The following article has been accepted by Review of Scientific Instruments. After it is published, it will be found at http://aip.scitation.org/journal/rs

Stress Conditions Induced by Carvacrol and Cinnamaldehyde on Acinetobacter baumannii

Acinetobacter baumannii has emerged as a major cause of nosocomial infections. The ability of A. baumannii to display various resistance mechanisms against antibiotics has transformed it into a successful nosocomial pathogen. The limited number of antibiotics in development and the disengagement of the pharmaceutical industry have prompted the development of innovative strategies. One of these strategies is the use of essential oils, especially aromatic compounds that are potent antibacterial molecules. Among them, the combination of carvacrol and cinnamaldehyde has already demonstrated antibacterial efficacy against A. baumannii. The aim of this study was to determine the biological effects of these two compounds in A. baumannii, describing their effect on the rRNA and gene regulation under environmental stress conditions. Results demonstrated rRNA degradation by the carvacrol/cinnamaldehyde mixture, and this effect was due to carvacrol. Degradation was conserved after encapsulation of the mixture in lipid nanocapsules. Results showed an upregulation of the genes coding for heat shock proteins, such as groES, groEL, dnaK, clpB, and the catalase katE, after exposure to carvacrol/cinnamaldehyde mixture. The catalase was upregulated after carvacrol exposure wich is related to an oxidative stress. The combination of thiourea (hydroxyl radical scavenger) and carvacrol demonstrated a potent bactericidal effect. These results underline the development of defense strategies of the bacteria by synthesis of reactive oxygen species in response to environmental stress conditions, such as carvacrol

Silencing of β-1,3-glucanase genes in tobacco correlates with an increased abundance of RNA degradation intermediates

Post-transcriptional gene silencing of beta-1,3 glucanase genes in the transgenic tobacco line T17 is characterised by an increased turnover and, as a consequence, reduced levels of gn1 transgene and endogenous beta-1,3 glucanase mRNAs, Here, additional gn1 RNAs, both larger and smaller than the full-length messenger, are shown to accumulate in silenced plants of the transgenic tobacco line T17, The longer-than-full-length gn1 RNAs are the result of cryptic processing of the gn1 messenger, The small gnl RNAs in silenced plants correspond to distal and proximal parts of the mature gn1 messenger. The proximal RNA products are intact at their 5' extremity, but terminate at different positions at the 3'-end. The distal RNA products contain a poly(A) tail and are truncated to various positions at the 5'-end, These observations indicate that degradation of the mature gnl transcript does not start at the 5'- or 3'-end, but rather are consistent with degradation of the gnl transcript starting with an endonucleolytic cleavage followed by internal exonuclease digestion. Importantly, the truncated products are more abundant in silenced plants than in expressing plants, This suggests, together with the previously reported silencing-related increased gnl mRNA turnover and the similar rates of gnl transcription in silenced and expressing T17 plants, that the predominant decay route for the gnl transcripts differs between silenced and expressing conditions

Letters from Colonial Secretary's Office to Captain Booth, Van Diemen's Land 1836-1841

Letters from the Colonial Secretary's Office to Captain Booth, 1836-1841 regarding the Lt. Governor's recent inspection of the settlement at Port Arthur where Booth was Commandant. RS31/5-1

Massagem no recém–nascido pré–termo: é um cuidado de enfermagem seguro?

Este estudo experimental de natureza quantitativa avaliou os efeitos da massagem no recém-nascido pré-termo internado em unidades de cuidados intermédios neonatais a nível da estabilidade fisiológica. Material e métodos: A amostra foi constituída por 32 recém-nascidos pré-termo clinicamente estáveis e saudáveis, internados em unidades portuguesas de cuidados intermédios neonatais. Os recém-nascidos pré-termo foram distribuídos aleatoriamente para os grupos controlo e experimental, em número igual de dezasseis. Em várias variáveis basais os grupos não apresentaram diferenças estatisticamente significativas, obtendo-se assim grupos equivalentes. O grupo experimental apresentou em média 30,11 semanas de gestação, 1,326 Kg de peso ao nascer e 20,44 dias de duração do internamento na unidade de cuidados intermédios. O grupo de controlo apresentou em média 30,94 semanas de gestação, 1,409 Kg de peso ao nascer e 17,81 dias de duração do internamento na unidade de cuidados intermédios. Durante o estudo os grupos receberam o mesmo padrão de cuidados neonatais à excepção do grupo experimental que recebeu a massagem. A massagem administrada foi a de Tiffany Field (Touch Research Institute), durante cinco dias consecutivos em três períodos diários. Foi administrada por enfermeiras das respectivas unidades, sendo estas execuções fidedignas e válidas, com homogeneidade inter-aplicadores da técnica quase perfeita (96,7 %) e com elevada validade de execução nomeadamente 96,77 % de concordância 1. Resultados: Para avaliar o efeito da massagem na estabilidade do recém-nascido pré-termo mediram-se os parâmetros fisiológicos: frequência respiratória e cardíaca, saturação de oxigénio, tensão arterial e temperatura. Quanto a estes verificamos não haver diferenças estatisticamente significativas entre os grupos pelo que concluímos que a massagem é um cuidado de enfermagem seguro em termos de organização do subsistema autónomo. Conclusões: Estes resultados obtidos sugerem que a massagem nos recém-nascidos pré-termo saudáveis e clinicamente estáveis internados em unidades de cuidados intermédios estudados foi uma intervenção segura

CHARACTERIZATION OF F107 FIMBRIAE OF ESCHERICHIA-COLI 107/86, WHICH CAUSES EDEMA DISEASE IN PIGS, AND NUCLEOTIDE-SEQUENCE OF THE F107 MAJOR FIMBRIAL SUBUNIT GENE, FEDA

F107 fimbriae were isolated and purified from edema disease strain 107/86 of Escherichia coli. Plasmid pIH120 was constructed, which contains the gene cluster that codes for adhesive F107 fimbriae. The major fimbrial subunit gene, fedA, was sequenced. An open reading frame that codes for a protein with 170 amino acids, including a 21-amino-acid signal peptide, was found. The protein without the signal sequence has a calculated molecular mass of 15,099 Da. Construction of a nonsense mutation in the open reading frame of fedA abolished both fimbrial expression and the capacity to adhere to isolated porcine intestinal villi. In a screening of 28 reference edema disease strains and isolates from clinically ill piglets, fedA was detected in 24 cases (85.7%). In 20 (83.3%) of these 24 strains, fedA was found in association with Shiga-like toxin II variant genes, coding for the toxin that is characteristic for edema disease strains of E. coli. The fimbrial subunit gene was not detected in enterotoxigenic E. coli strains. Because of the capacity of E. coli HB101(pIH120) transformants to adhere to isolated porcine intestinal villi, the high prevalence of fedA in edema disease strains, and the high correlation with the Shiga-like toxin II variant toxin-encoding genes, we suggest that F107 fimbriae are an important virulence factor in edema disease strains of E. coli