Complexation of aromatic dichalcogen ligands to germanium

Eight novel germanium compounds of the type [R2Ge(E-Ar-E)], where R = Me, Ph; E-Ar-E = an aromatic bidentate chalcogen ligand, were successfully synthesised. The effects of changing 3 variables within the series were investigated. These variables included the chalcogen (E = S/Se), aromatic backbone (Ar = Nap/Biphenyl) and R group (Me/Ph) employed. The choice of aromatic backbone had the greatest effect on the structure. A substantial change in geometry around the germanium centre was observed within the solid state structures depending on whether the backbone was naphthalene or biphenyl. This affected the stability of the compound and resulted in the visible decomposition of two selenium complexes over several days. All novel compounds were characterised by multinuclear NMR, IR, mass spectroscopy and single crystal X-ray diffraction.PostprintPeer reviewe

The preparation and characterisation of rhodium(III) and Iridium(III) half sandwich complexes with napthalene-1,8-dithiolate, acenaphthene-5,6-dithiolate and biphenyl-2,2′-dithiolate

The synthesis of rhodium(III) and iridium (III) half sandwich complexes [Cp*M(PEt3) (S-R-S)], M = Rh, Ir; S-R-S = naphthalene-1,8-dithiolate (NaphthS2, a), acenaphthene-5,6-dithiolate (AcenapS2, b) and biphenyl-2,2′-dithiolate (BiphenS2, c) is reported. We also describe the isolation of a new compound acenaphthene-1,8-dithiol. All complexes have been fully characterised using multinuclear NMR spectroscopy and single crystal X-ray diffraction. The ligands naphthalene-1,8-dithiol (H2a), acenaphthene-1,8-dithiol (H2b), 1,1′-biphenyl-2,2′-dithiol (H2c) and benzene-1,2-dithiol (H2d) have also been characterised by single crystal X-ray diffraction.PostprintPeer reviewe

Tumor Microbiome Diversity and Composition Influence Pancreatic Cancer Outcomes

Most patients diagnosed with resected pancreatic adenocarcinoma (PDAC) survive less than 5 years, but a minor subset survives longer. Here, we dissect the role of the tumor microbiota and the immune system in influencing long-term survival. Using 16S rRNA gene sequencing, we analyzed the tumor microbiome composition in PDAC patients with short-term survival (STS) and long-term survival (LTS). We found higher alpha-diversity in the tumor microbiome of LTS patients and identified an intra-tumoral microbiome signature (Pseudoxanthomonas-Streptomyces-Saccharopolyspora-Bacillus clausii) highly predictive of long-term survivorship in both discovery and validation cohorts. Through human-into-mice fecal microbiota transplantation (FMT) experiments from STS, LTS, or control donors, we were able to differentially modulate the tumor microbiome and affect tumor growth as well as tumor immune infiltration. Our study demonstrates that PDAC microbiome composition, which cross-talks to the gut microbiome, influences the host immune response and natural history of the disease. The distinct tumor microbiome from pancreatic cancer long-term survivors can be used to predict PDAC survival in humans, and transfer of long-term survivor gut microbiomes can alter the tumor microbiome and tumor growth in mouse models

Ileal immune tonus is a prognosis marker of proximal colon cancer in mice and patients

Ileal epithelial cell apoptosis and the local microbiota modulate the effects of oxaliplatin against proximal colon cancer by modulating tumor immunosurveillance. Here, we identified an ileal immune profile associated with the prognosis of colon cancer and responses to chemotherapy. The whole immune ileal transcriptome was upregulated in poor-prognosis patients with proximal colon cancer, while the colonic immunity of healthy and neoplastic areas was downregulated (except for the Th17 fingerprint) in such patients. Similar observations were made across experimental models of implanted and spontaneous murine colon cancer, showing a relationship between carcinogenesis and ileal inflammation. Conversely, oxaliplatin-based chemotherapy could restore a favorable, attenuated ileal immune fingerprint in responders. These results suggest that chemotherapy inversely shapes the immune profile of the ileum-tumor axis, influencing clinical outcome

Influence of the Escherichia coli oxyR gene function on λ prophage maintenance

In Escherichia coli hosts, hydrogen peroxide is one of the factors that may cause induction of λ prophage. Here, we demonstrate that H2O2-mediated λ prophage induction is significantly enhanced in the oxyR mutant host. The mRNA levels for cI gene expression were increased in a λ lysogen in the presence of H2O2. On the other hand, stimulation of the pM promoter by cI857 overproduced from a multicopy plasmid was decreased in the ΔoxyR mutant in the presence of H2O2 but not under normal growth conditions. The purified OxyR protein did bind specifically to the pM promoter region. This binding impaired efficiency of interaction of the cI protein with the OR3 site, while stimulating such a binding to OR2 and OR1 sites, in the regulatory region of the pM promoter. We propose that changes in cI gene expression, perhaps in combination with moderately induced SOS response, may be responsible for enhanced λ prophage induction by hydrogen peroxide in the oxyR mutant. Therefore, OxyR seems to be a factor stimulating λ prophage maintenance under conditions of oxidative stress. This proposal is discussed in the light of efficiency of induction of lambdoid prophages bearing genes coding for Shiga toxins

Residues of chlorinated pesticides in mother\u27s milk and child\u27s serum

Uzorci mlijeka i seruma 27 hospitaliziranih dojilja iz Bjelovara i Zaboka s okolnim mjestima analizirani su na ostatke kloriranih insekticida aldrina, dieldrina, endrina, heptaklora, heptaklor epoksida, lindana i ostalih stereoizomera heksaklorcikloheksana, pp-\u27DDT-a i metabolita (pp-\u27DDE i pp-\u27DDD) i op-\u27DDT. Posebno je još analizirano 18 seruma majki i isto toliko seruma njihove djece koji su svi iz Zagreba. U uzorcima smo dokazali prisutnost samo Gama-HCH (Lindan). Alfa-HCH, pp-\u27DDE, op-\u27DDT, pp-\u27DDD i pp-\u27DDT. Koncentracije nađenih insekticida mnogo su veće u mlijeku dojilja nego u serumima. U serumima djece bilo je manje samo pp-\u27DDE i pp-\u27DDT nego u serumima njihovih majki. Uzorci seruma dojilja iz Zaboka i okolnih mjesta, hospitaliziranih u Zaboku i serumi dojilja iz Bjelovara hospitaliziranih u Zagrebu (N = 27) sadržavaju više navedenih insekticida nego uzorci seruma dojilja s područja Zagreba (N = 18).Milk samples obtained from 27 hospitalized lactating women and an equal number of sera from the same women were examined for residues of chlorinated hydrocarbon insecticides: aldrin, dieldrin, endrin, heptachlor, heptachlorepoxide, lindan and other steroisomers of hexachlorcyclohexane, pp\u27DDT and its metabolites (pp\u27-DDE, pp\u27-DDD) and op\u27-DDT. Additional 18 samples of mother\u27s sera and an equal number of their children\u27s sera were examined separately. The aim was to find out whether there is a correlation between the pesticide residues in mother\u27s serum and mother\u27s milk and in the serum of the mother and her child. The insecticides were determined according to the procedure used by the US Food and Drug Administration (4). Chlorinated hydrocarbon insecticides in the serum were examined with the method described by Wyllie and coworkers (5). In all samples only the presence of a-HCH, y-HCH, pp\u27-DDE, op\u27-DDT, pp\u27-DDD and pp\u27-DDT could be demonstrated. The concentration ratio between mother\u27s milk and serum was between 4 and 11. The concentration ratio between mother\u27s and child\u27s serum was below 1 except for pp\u27-DDE and pp\u27-DDT

Processing of Copper by Hydrostatic Extrusion – Studies of Microstructure and Properties

The present study attempts to apply HE to 99.99% pure copper. The microstructure of the samples was investigated by both light microscopy and scanning transmission electron microscopy (STEM). Additionally, the microhardness was measured, the tensile test was made, and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns, misorientation was determined. The obtained results show that microstructure of copper deformed by hydrostatic extrusion (HE) is rather inhomogeneous. The regions strongly deformed with high dislocation density exist near cells and grains/subgrains free of dislocations. The measurements of the grain size have revealed that the sample with an initial in annealed-state grain size of about 250 μm had this grain size reduced to below 0.35μm when it was deformed by HE to the strain ε=2.91. The microhardness and UTS are stable within the whole investigated range of deformation

A new technique for real-time measurements of potassium and sodium aerosols based on field-reversal surface ionization

A new method for real-time measurements of potassium and sodium containing aerosol particles is described and verified. The method is based on surface ionization technique and may be used to explore the alkali chemistry related to high temperature chemistry processes. The measurement device is a further development of the simple and cost-effective surface ionization detector previously used for online alkali measurements in combustion and gasification research. The discrimination between sodium and potassium is possible due to differences in their surface desorption kinetics and facilitated by rapidly reversing the field potential between the ion source and the nearby collector. The instrument is evaluated in a series of laboratory experiments using size-selected alkali salt particles containing KCl, NaCl, K2SO4, Na2SO4, KNO3 and NaNO3. The filament temperature was found to be a key influencing factor in order to optimize the strength and Na-K deviation of the observed ion current. The ability to simultaneously report absolute concentrations of Na and K makes the instrument attractive for solid fuel conversion of alkali-rich fuels such as low-grade biomass and to explore behavior deviations of Na and K in high temperature processes

Tricuspid valvectomy for right ventricular outflow cannula occlusion with the Thoratec ventricular assist device

AbstractJ Thorac Cardiovasc Surg 2001;121:812-