Search Results - (Author, Cooperation:A. H. Berg)

2016-03-17

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

3-Hydroxybutyric Acid/metabolism ; Acute Kidney Injury/drug therapy/*metabolism ; Adipose Tissue/drug effects/metabolism ; Amino Acids/metabolism ; Animals ; Cytokines/metabolism ; Dinoprostone/biosynthesis/metabolism ; Humans ; Ischemia/drug therapy/metabolism ; Kidney/drug effects/*metabolism/physiology/physiopathology ; Male ; Mice ; Mice, Inbred C57BL ; Mitochondria/metabolism ; NAD/*biosynthesis ; Niacinamide/deficiency/pharmacology/therapeutic use ; Nicotinamide Phosphoribosyltransferase/metabolism ; Oxidation-Reduction ; Signal Transduction/drug effects ; Stress, Physiological ; Transcription Factors/deficiency/*metabolism

2018-03-28

The American Society for Microbiology (ASM)

0066-4804

1098-6596

Biology

Medicine

1432-0703

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Abstract. In the present study, four structurally diverse polychlorinated biphenyls (PCBs) were chosen from a set of 20 PCBs selected to represent the 154 tetra- through hepta-chlorinated biphenyls. The purpose was to determine estrogenic activities of the chosen PCBs and five of their hydroxylated derivatives (OH-PCBs). A human breast cancer cell line (MCF-7) and primary cultures of rainbow trout (Oncorhyncus mykiss) hepatocytes were used to determine estrogenic effects. The PCBs 2,2′,4,6,6′-pentachlorobiphenyl (104) and 2,2′,3,4′, 5,6,6′-heptachlorobiphenyl (188), and the hydroxylated PCBs 2,2′,4′,6′-tetrachloro-4-biphenylol (4′-50), 2′,4′,6′-trichloro-4-biphenylol (4′-30), 2′,3,5,5′-tetrachloro-4-biphenylol (4′-72), 2′,3,3′,5′,6′-pentachloro-4-biphenylol (4′-112), and 2′,3,4′,5,6′-pentachloro-4-biphenylol (4′-121) significantly increased MCF-7 cell proliferation. The coaddition of hydroxytamoxifen, an estrogen antagonist, inhibited increased cell proliferation. The activity of the hydroxylated PCBs 4′-50 and 4′-30 was significantly higher at all nominal concentrations tested as compared to the corresponding PCB, viz., PCB 104. The hydroxylated PCBs 4′-50, 4′-30, 4′-72 and 4′-112 induced vitellogenin synthesis in rainbow trout hepatocytes. Significant differences were found in the MCF-7 system between the parent PCB and its hydroxylated derivative, viz., for 4′-50/4′-30 and 104, and in the rainbow trout hepatocyte assay between 4′-112 and 112, respectively. No activity was observed for PCB 58 in any of the two assays in the present study. Even though cells from two different species (human and fish) are used in the present study, the results obtained by the two methods agree fairly well. In both studies the hydroxylated PCBs were more active than the PCBs, and 4′-30 was the most active compound second only to 17β-estradiol.

Electronic Resource

1432-0703

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Abstract. Juvenile Baltic salmon, Salmo salar, were fed commercial salmon food contaminated with different concentrations of polychlorinated naphthalenes (PCNs; 0.1, 1, 2, or 10 μg PCN/g food). Among other effects, possible estrogenic impact caused by PCNs were evaluated. Fish were therefore fed a diet contaminated with 17β-estradiol (E2; 0.94 or 9.4 μg E2/g food), as a positive control. After 8, 13, 17, and 41 weeks, sampling took place. Growth, liver somatic index (LSI), EROD activity, and vitellogenin content in blood plasma were measured along with morphological studies of gonads and chemical analyses to determine the effects caused by PCNs. Exposure to PCNs did not seem to have any effects on body weight gain, since the group fed the high dose followed the growth in the control group during the entirely experimental period. After 41 weeks of exposure the groups fed 2 and 10 μg PCN/g food had significantly lower LSIs compared with the control, indicating liver toxic effects of PCNs. Furthermore, a dose-dependent induction of EROD activity was found. At week 41, the control group had an activity of 4.9 ± 4.8 pmol/mg prot/min, whereas it was between 69 ± 21 and 720 ± 370 pmol/mg prot/min in the exposed groups, respectively. Examination of gonadal morphology showed that PCNs also had negative effects on ovaries in Baltic salmon, including delayed development. The distribution between females and males, gonadal morphology, and vitellogenin content in blood plasma did, however, indicate that PCNs are not capable of causing effects similar to E2 or xenoestrogens. Exposure to both of the concentrations of E2 resulted in decreased body weight gain, increased LSI, and feminization of the gonads. E2 did, however, not induce any EROD activity.

Electronic Resource

1432-1130

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Thin alumina films, deposited at 280° C on several high alloyed steels by low pressure metal-organic chemical vapour deposition (LP-MOCVD), were annealed at 0.17 kPa in a nitrogen atmosphere for 2, 4 and 17 h at 600 and 800° C. The effect of the annealing process on the adhesion of the thin alumina films was studied using a scanning scratch tester (SST) and Auger electron spectroscopy (AES). The best adhesion properties were obtained with commercial oxide dispersion strengthened (ODS) high temperature alloys, especially type PM 3030. From the “normally” high alloyed stainless steels, type AISI-321 showed the best properties. The other stainless steel – alumina combinations showed after a thermal treatment a decrease of the critical load, Lc. Using ODS alloys as the substrate resulted in an increased Lc. AES-studies revealed that the increased Lc can be explained by 1) the presence of sulphur trapping elements, avoiding segregation of sulphur near the interface which could have a detrimental effect on scale adherence, and 2) titanium and carbon enrichment at the interface resulting in a beneficial effect on the adherence between the oxide and the substrate.

Electronic Resource

1432-1130

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Thin titanium and titanium oxide films, both covered by ultra-thin gold layers, have been compared with titanium films after analysis, using a combination of SEM and AES. The Ti films were prepared under UHV conditions by evaporation on a glass substrate. The Ti oxide layers were prepared in situ by precisely controlled oxygen sorption at 298 K on Ti film. Both Ti and Ti oxide films were then covered in situ by a very thin Au layer. Analysis was performed in a separate system after long-term exposure of the films to air. SEM analysis revealed a much smaller size grain on the Au coated Ti films than on Ti films not coated with a Au layer. The thin gold layers covering the Ti surface prevent an extensive air interaction with Ti film. The analysis of the features of the Ti Auger spectra during the sputter profile measurements allow to characterise the chemical nature of Ti-oxide formed in Ti/Au interface region.

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Summary For the first time, both X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) techniques were applied in analysis of surface contamination of electrochemically etched Scanning Tunneling Microscope (STM) tungsten tips. Carbon monoxide, graphite, tungsten carbide and tungsten oxide were found as main surface contaminations of STM tungsten tips. The thickness of tungsten oxide layers was estimated to be about 1–3 nm. Quantitative analysis of surface and bulk concentration of carbon, oxygen and tungsten has been performed.

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Thin alumina films deposited by metal-organic chemical vapour deposition (MOCVD) on AISI 304 substrate have been analyzed using the combination of Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES) and Angle Resolved X-ray Photoelectron Spectroscopy (ARXPS). Both the surface and the alumina/substrate interface region have been analyzed in terms of chemical composition and elemental distribution. Only OH-groups (bounded as AlO(OH):boehmite) have been found as an impurity in the surface region of the oxide film. No carbon was detected. Due to higher temperature deposition, the concentration of OH-groups decreased. After annealing, the oxide/substrate interface changes as a result of chromium penetration into the alumina matrix. Carbon impurities have been detected on both delaminated and annealed alumina film surfaces. Also small amounts of sulfate groups as well as Ca and C impurities have been found on delaminated alumina film after prolonged high-temperature annealing.

Electronic Resource

0142-2421

Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Physics

A combination of SEM, AES and angle-resolved XPS (ARXPS) has been applied to analyse the distribution of chemical compounds in the surface region of electrochemically etched molybdenum tips and to determine the contamination layer thickness. Carbon monoxide, graphite, molybdenum carbide and molybdenum oxide were found to be the main surface contaminants on molybdenum tips. Auger line profiling revealed a significant enrichment of carbon and oxygen upon the tip. The thickness of the oxygen-carbon contamination layer on the tip was estimated to be 13.5 ± 1.0 nm as measured by AES. The thickness of the contamination layer on a molybdenum sheet was found to be 8.0 ± 1.5 and 6.8 nm using AES and ARXPS respectively. Quantitative analysis of the surface concentrations of carbon, oxygen and molybdenum has been performed.

8 Ill.

Electronic Resource

0142-2421

titanium ; titanium hydride ; SEM ; ARXPS ; AES depth profiles ; Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Physics

Thin titanium hydride (TiHy) films are compared with thin titanium films after analysis using a combination of scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and angle-resolved x-ray photoelectron spectroscopy (ARXPS). The TiHy films were prepared under ultrahigh vacuum conditions by precisely controlled hydrogen sorption at 298 K on Ti films evaporated onto a glass substrate. Analysis was performed in separate systems after long-term exposure of the films to air. Scanning electron microscopy analysis revealed a grain structure of the TiHy film, with a smaller grain size than the Ti film. Both the surface and bulk regions have been analysed in terms of their chemical composition and elemental distribution. Titanium dioxide was found to be the main chemical compound forming a contamination layer on both the TiHy and Ti film surfaces. Also, significant concentrations of carbon monoxide and hydrocarbon as well as small amounts of nitrogen and titanium carbide were detected. The thickness of the contaminated titanium oxide layer on the TiHy and Ti films was found to be ∽13 and ∽20 nm, respectively. Long-term air interaction with the TiHy film leads to bulk penetration of oxygen but not to complete TiHy decomposition. © 1998 John Wiley & Sons, Ltd.

7 Ill.

Electronic Resource