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Manganese oxides from the compound family of layered birnessites have attracted interest for their use as cathode materials in Li-ion batteries, as supercapacitors, and as water oxidation catalysts. Furthermore, birnessites are also excellent precursors for low-temperature syntheses of manganese oxide-based materials such as LiMn2O4 (spinel and hollandite). Most syntheses leading to highly crystalline birnessites either require hydrothermal conditions for extended periods of time ranging from days to months or a high post-treatment temperature (400-500 °C). Here, we present a novel sol-gel synthesis route leading to the formation of highly crystalline birnessites within one hour without the need for any post-treatment to enhance crystallinity. Small birnessite crystals form virtually immediately upon mixing of the reactants, albeit initially of lower crystallinity. The size of the fully developed monoclinic birnessite platelets is in the micrometer-range with a thickness of about 20-50 nm. Under the studied conditions, the presence of Li+, Na+, and K+ is necessary for the formation of well-crystallized birnessites, and the crystal size can be tuned by variation of the synthesis time. This is suggested to be linked to an increase of the Na+ content in the birnessite with increasing synthesis time.

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Urinary retention secondary to benign prostatic hyperplasia is considered an absolute indication for surgical treatment of the prostate. Transurethral resection of the prostate is still considered the gold standard in terms of effectiveness. One of several new techniques for treatment of BPH is transurethral microwave thermotherapy (TUMT). Our first experiences with this technique in a group of patients with urinary retention were analysed retrospectively. In the short term 16 of the 25 treated patients were able to void spontaneously with acceptable bladder emptying (64%, 95% CI: 43-85). Later on, three of these initial successes received further treatments for BPH, two had a transurethral resection of the prostate and one was given medical therapy. No serious complication was seen except in one patient who developed a urethrorectal fistula which healed following conservative treatment. The success rate following TUMT was inferior to that of standard transurethral resection, but TUMT seems an acceptable alternative in patients with pronounced co-morbidity.

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OBJECTIVES: To investigate the specificity of biological monitoring variables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, 32P postlabelling assay, measurement of sister chromatid exchange) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (alkaline filter elution assay), sister chromatid exchange, and DNA adducts (32P postlabelling assay) in lymphocytes. Phenanthrene and pyrene metabolites were measured in 24 hour urine samples. 19 different PAHs (including benzo(a)pyrene, pyrene, and phenanthrene) were measured at the workplace by personal air monitoring. The GSTT1 activity in erythrocytes and lymphocyte subpopulations in blood was also measured. RESULTS: Concentrations of phenanthrene, pyrene, and benzo(a)pyrene in air correlated well with the concentration of total PAHs in air; they could be used for comparisons of different workplaces if the emission compositions were known. The measurement of phenanthrene metabolites in urine proved to be a better biological monitoring variable than the measurement of 1-hydroxypyrene. Significantly more DNA strand breaks in lymphocytes of coke oven workers were found (alkaline filter elution assay); the DNA adduct rate was not significantly increased in workers, but correlated with exposure to PAHs in a semiquantitative manner. The number of sister chromatid exchanges was lower in coke oven workers but this was not significant; thus counting sister chromatid exchanges was not a good variable for biomonitoring of coke oven workers. Also, indications for immunotoxic influences (changes in lymphocyte subpopulations) were found. CONCLUSIONS: The measurement of phenanthrene metabolites in urine seems to be a better biological monitoring variable for exposure to PAHs than measurement of hydroxypyrene. The alkaline filter elution assay proved to be the most sensitive biomarker for genotoxic damage, whereas the postlabelling assay was the only one with some specificity for DNA alterations caused by known compounds.

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A study was carried out of the quality and completeness of articles on adverse drug reactions: 5737 articles from 80 countries published between 1972 and 1979 were studied. Only 61% of the articles included information on the number of patients treated and the number with adverse drug reactions, yet these are essential for calculating the incidence of adverse reactions. In only 55% could the incidence of a particular adverse reaction be calculated. Great importance is placed on articles on adverse reactions, particularly those that report on many patients. Authors and editors should ensure that articles include the following information: drug regimens, numbers of patients treated, numbers of patients developing adverse reactions, and nature and incidence of adverse reactions.

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N(2) fixation in field-grown maize (Zea mays L.) plants was estimated by a nondestructive acetylene reduction method which permitted the plants to continue growing and produce seeds. Samples from six areas revealed mean nitrogenase activities of 74-2167 nmol of C(2)H(4)/(g of dry roots x hr) for 10 plants. Among 276 S(1) lines planted in two field experiments, 17 lines were selected for further nitrogenase activity assays after prescreening. Variability within lines was high but significant differences among lines were obtained in one experiment. The best lines showed mean nitrogenase activities of 2026, 2315, and 7124 nmol of C(2)H(4)/(g of dry roots x hr), whereas the original cultivar reduced only 313 nmol. The highest value approaches the nitrogenase activity of soybean. If the theoretical 3:1 (C(2)H(4)/N(2) reduced) conversion factor is used, a potential daily N(2) fixation of 2 kg of N(2)/hectare can be calculated. Periodic sampling within a brachytic maize cultivar revealed that maximum nitrogenase activity occurred at about the 75% silking stage. Soil effects also were pronounced. N(2)-fixing Spirillum sp. could be isolated from all active root pieces when they were surface sterilized. These organisms appear to be primarily responsible for root nitrogenase activity in maize.