Photocatalysis for continuous air purification in wastewater treatment plants: from lab to reality.

The photocatalytic efficiency of TiO(2)-SiMgO(x) plates to oxidize H(2)S was first evaluated in a flat laboratory reactor with 50 mL min(-1) synthetic air containing 100 ppm H(2)S in the presence of humidity. The use of the photocatalyst-adsorbent hybrid material enhanced the photocatalytic activity in terms of pollutant conversion, selectivity, and catalyst lifetime compared to previous H(2)S tests with pure TiO(2) because total H(2)S elimination was maintained for more than 30 operating hours with SO(2) appearing in the outlet as reaction product only after 18 h. Subsequently, the hybrid material was successfully tested in a photoreactor prototype to treat real polluted air in a wastewater treatment plant. For this purpose, a new tubular photocatalytic reactor that may use solar radiation in combination with artificial radiation was designed; the lamp was turned on when solar UV-A irradiance was below 20 W m(-2), which was observed to be the minimum value to ensure 100% conversion. The efficient distribution of the opaque photocatalyst inside the tubular reactor was achieved by using especially designed star-shaped structures. These structures were employed for the arrangement of groups of eight TiO(2)-SiMgO(x) plates in easy-to-handle channelled units obtaining an adequate flow regime without shading. The prototype continuously removed during one month and under real conditions the H(2)S contained in a 1 L min(-1) air current with a variable inlet concentration in the range of tens of ppmv without release of SO(2).

Crystal structure and spectroscopic properties of CsVO2SO4.

Dark crystals of the V(V) compound CsVO(2)SO(4), suitable for X-ray investigations have been obtained from the catalytically important Cs(2)S(2)O(7)-V(2)O(5) system. By cooling of the mixture with the composition X(V)2(O)5 = 0.5, some crystals were obtained in the otherwise glassy sample. The compound crystallizes in the orthorhombic space group Pbca with a = 6.6688(13) A, b = 10.048(2) A, and c = 17.680(4) A at 20 degrees C and Z = 8. It contains a coordination sphere with a short V-O bond of 1.595(2) A and trans to this the closest VO distance at 3.4 A and four equatorial V-O bonds in the range 1.725(1)-1.984(2) A. The deformation of the VO(6) octahedron is thus much more pronounced compared to other known oxo sulfato V(V) compounds, and the coordination polyhedron of V(V) should be regarded as a tetragonal pyramid with the vanadium atom in the center. Each VO(2)(+) group is coordinated to the neighboring groups by oxygen and sulfate double bridges in a zigzag structure where two sulfate oxygens virtually remain uncoordinated-one is found at the very long nonbonding V-O distance from the neighboring chain. This is the first time that we find pentacoordination of vanadium in the 12 different V(III), V(IV), and V(V) compounds examined so far. The FTIR and Raman spectra of the compound are in agreement with the simple formula unit of the investigated compound.

Evidence for the transforming activity of a truncated Int6 gene, in vitro.

Int6/eIF3-p48 was first identified as a common integration site for MMTV in mouse mammary tumors. In all cases, the MMTV integration event resulted in an interruption of the normal Int6 transcript from one allele leaving the second allele intact and operative. We hypothesize that insertion of MMTV into Int6 results in a mutated allele that encodes a shortened Int6 mRNA and protein (Int6sh), which either modifies normal Int6 function or possesses a new independent function. To confirm the transforming potential of the mutation and its dominant function, we transfected two mammary epithelial cell lines, MCF10A (human), and HC11 (mouse), with Int6sh under the control of the elongation factor-1alpha (eEF1A) promoter. Expression of Int6sh in MCF10A and HC11 mammary epithelial cells leads to anchorage-independent growth in soft agar indicative of a transformed phenotype. Colonies selected from agar exhibited high levels of mutated Int6sh and wild type Int6 RNA transcripts by RT-PCR and Northern blot analysis. In addition, Int6sh transformed MCF10A and HC11 cells formed nodular growths, in vivo, in immune compromised hosts. NIH3T3 cells, mouse embryo fibroblasts, were also transformed to anchorage-independent growth in vitro by Int6sh expression. These observations provide direct evidence that the Int6 mutations observed in MMTV-induced tumors and hyperplasia contribute to the malignant transformation of the mammary epithelial cells.

Functional rest through intensive treatment with insulin and potassium channel openers preserves residual beta-cell function and mass in acutely diabetic BB rats.

Diazoxide and the diazoxide-analogue, NNC 55-0118, are potassium channel openers that interfere with insulin secretion from beta-cells. In vitro, we show that these two drugs inhibit insulin release from diabetes-resistant BB rat islets cultured at either low or high glucose concentration and cause an intracellular accumulation of insulin with high glucose. Preservation of beta-cells was investigated in newly diabetic BB rats treated with insulin implants from day 0-8 under oral diazoxide, NNC 55-0118 or solvent gavage once a day from day 0-7. Three of eight rats (37.5%) treated with diazoxide and three of ten (30%) treated with NNC 55-0118 retained near normal C-peptide responses when challenged with glucose/arginine on day 9, whereas none of eight (0%) solvent-treated rats showed a C-peptide response. Immunohistochemical staining for insulin and glucagon showed that all the C-peptide responding rats had insulin-positive cells in their islets. In contrast, islets from non-responding rats displayed marked inflammation or end-stage lesions. Furthermore, rats with C-peptide response and treated with NNC 55-0118 exhibited only minimal signs of islet inflammation, whereas C-peptide responding diazoxide-treated rats had low level islet inflammation. These results imply that it is conceivable to preserve residual beta-cells at diabetes onset by induction of target cell rest with potassium channel openers and continuous insulin treatment.

Mapping of caspase-2 in the rat and its exclusion as a candidate gene for lymphopenia.

Caspase-2 is a member of the caspase family of cystein proteases involved in programmed cell death or apoptosis. Functional and genetic data suggest it as a candidate gene for lymphopenia (Lyp)-a susceptibility gene for rat diabetes-which is responsible for the T-cell lymphopenia in the diabetes-prone BB rat. Firstly, there is a higher frequency of apoptosis among recent thymic emigrants in the diabetes-prone BB rat than in the non-lymphopenic diabetes-resistant BB rat. Secondly, caspase-2 maps close to Tcrb on mouse Chromosome (Chr) 6, while Lyp is closely linked to Tcrb on the homologous rat Chr 4. In this paper, we report genetic fine-positioning and radiation hybrid mapping of caspase-2 in the rat. Both methods positioned caspase-2 to rat Chr 4 between markers Prss1 and D4Mit5. Since Lyp maps distally to D4Mit5, between markers D4Rat75 and Npy, we exclude caspase-2 as a candidate gene for Lyp.

Chromosomal mapping and mutational analysis of the coding region of the glycogen synthase kinase-3alpha and beta isoforms in patients with NIDDM.

Activation of glycogen synthesis in skeletal muscle in response to insulin results from the combined inactivation of glycogen synthase kinase-3 (GSK-3) and activation of the protein phosphatase-1, changing the ratio between the inactive phosphorylated state of the glycogen synthase to the active dephosphorylated state. In a search for genetic defects responsible for the decreased insulin stimulated glycogen synthesis seen in patients with non-insulin-dependent diabetes mellitus (NIDDM) and their glucose-tolerant first-degree relatives we have performed mutational analysis of the coding region of the 2 isoforms of GSK-3alpha and GSK-3beta in 72 NIDDM patients and 12 control subjects. No structural changes were detected apart from a few silent mutations. Mapping of the GSK-3alpha to chromosome 19q13.1-13.2 and the GSK-3beta to chromosome 3q13.3-q21 outside known genetic loci linked to NIDDM further makes it unlikely that these genes are involved in the pathogenesis of common forms of NIDDM.

Identification of two novel missense mutations in the human OB gene.

OBJECTIVE: To clone the human OB gene and to investigate if mutations in the OB gene are related to juvenile onset obesity in Caucasians. DESIGN: Case-cohort study with mutational scanning of the OB gene in an obese cohort and in a population sample of young Caucasians. SUBJECTS: An obese cohort of 156 subjects with juvenile onset obesity and a population sample of 380 healthy young Caucasians. MEASUREMENTS: Various anthropometric and biochemical measures of obesity and insulin sensitivity and single strand conformation polymorphism scanning and nucleotide sequencing. RESULTS: Analysis of the coding region of the OB gene in the 536 participants revealed that one obese subject was heterozygous for a mutation at codon Phe17Leu and one normal weight subject was heterozygous for a mutation at codon Val110Met. The phenotypes of the carriers were not different from matched non-mutation carrying subjects. CONCLUSIONS: Mutations exist in the OB gene among obese as well as lean subjects although they are rare. However, it is unlikely that mutations in the coding region of the OB gene are a common cause of juvenile onset obesity among Caucasians.

[Panic disorder. The pattern of somatic contacts in patients]. / Panikangst. Patienters somatiske kontaktmønster.

The epidemiology, phenomenology and treatment of panic disorder have been thoroughly studied in recent years. The symptomatology of panic attacks may mimic cardiopulmonary, neurological and gastrointestinal disease. Forty Danish panic patients with panic disorder of ten years' duration had had contact with several medical specialists, hospital emergency and outpatient services. Thus, 28% had visited neurologists, 8% cardiologists and 20% an emergency service. One third had been admitted to hospital departments. Almost all patients had consulted psychiatrists or psychologists. Ninety had been treated with a benzodiazepine, 35% with tricyclic antidepressants and 57% with neuroleptics. To prevent costly medical testings and delay in accurate diagnosis in psychiatric and somatic settings, the phenomenology of panic disorders should be recognized by all medical specialists and general practitioners.