Tunable colors and conductivity by electroless growth of Cu/Cu2O particles on sol-gel modified cellulose

Nano Research - Development of colored surfaces by formation of nano-structured aggregates is a widely used strategy in nature to color lightweight structures (e.g. butterflies) without the use of...     

Reduced texaphyrin: A ratiometric optical sensor for heavy metals in aqueous solution

We report here a water-soluble metal cation sensor system based on the as-prepared or reduced form of an expanded porphyrin, texaphyrin. Upon metal complexation, a change in the redox state of the ligand occurs that is accompanied by a color change from red to green. Although long employed for synthesis in organic media, we have now found that this complexation-driven redox behavior may be used to achieve the naked eye detectable colorimetric sensing of several number of less-common metal ions in aqueous media. Exposure to In(III), Hg(II), Cd(II), Mn(II), Bi(III), Co(II), and Pb(II) cations leads to a colorimetric response within 10 min. This process is selective for Hg(II) under conditions of competitive analysis. Furthermore, among the subset of response-producing cations, In(III) proved unique in giving rise to a ratiometric change in the ligand-based fluorescence features, including an overall increase in intensity. The cation selectivity observed in aqueous media stands in contrast to what is seen in organic solvents, where a wide range of texaphyrin metal complexes may be prepared. The formation of metal cation complexes under the present aqueous conditions was confirmed by reversed phase high-performance liquid chromatography, ultra-violet-visible absorption and fluorescence spectroscopies, and high-resolution mass spectrometry.     

Cyromazine toxicity in different laboratory strains of the tobacco hornworm (Lepidoptera:Sphingidae)

Three different strains of tobacco hornworm, Manduca sexta (L.), were treated with cyromazine ingestion of cyromazine-treated artificial diet or by intrahemocoelic injection. The effect of cyromazine on larval growth and the onset and severity of poisoning symptoms were similar in the wild-type green-pigmented strain and the white-pigmented mutant. Feeding times of 4 h or greater and injected doses of 22.6 micrograms/g larva or more resulted in lower weight gains than were observed with controls. Elongation caused by exposure was evident within 12-24 h. The incidence of cuticular rupture was 55 and 67% in the dietary exposure tests and 24 and 22% in the injection tests for the green and white strains, respectively. The response of the black strain to cyromazine differed by the route of administration. Like the other strains, dietary exposure times of 4 h or greater led to smaller weight gains than in the controls. Injected doses of 2.8 micrograms/g larva or more caused a decrease in the weight gain of the treated versus controls. A smaller proportion (21%) of black larvae consuming treated diet developed cuticular ruptures, whereas injected treatments had a higher incidence (87%). The differences in the pigmentation of the white and black strains had been linked to high and low juvenile hormone titers, respectively. The greater susceptibility of the juvenile hormone-deficient black strain raises the possibility that the mode of action of cyromazine involves a hormonal component. In a separate series of experiments, the poisoning symptoms of cyromazine were attenuated or eliminated by periods of starvation of 1-3 d following exposure to the chemical. Starvation for 3 d preceding treatment attenuated but did not eliminate signs of poisoning.     

The future beckons [electric power industry]

This paper discusses the challenges that the US electric power industry has to face to continue to maintain the stable, reliable, and efficient system over the next few years. These challenges include an aging transmission system suffering from substantial underinvestment, the need for a regulatory framework that will spur independent investment, ownership and management of the nation's grid, and an aging workforce and the need for a succession plan to ensure the existence of the next generation of technical expertise in the industry. Through the efforts of many and by working together through concerned organizations, the industry can move forward to the benefit of the public and the US as a whole.     

Familial ring (19) chromosome mosaicism: case report and review

Ring (19) chromosomal mosaicism has been identified in a 14-month-old girl referred for cytogenetic evaluation due to microcephaly and developmental delay with autistic-like mannerisms. An analysis of her peripheral blood lymphocytes showed a 46,XX,r(19) cell line in 119/121 of cells examined. Of the two remaining cells, one had a normal female chromosome complement and the other showed loss of one of the chromosome 19 homologs. Further analysis by fluorescence in situ hybridization using an all human telomere probe showed the presence of a single hybridization signal on the r(19) chromosome. Subsequent cytogenetic characterization of cells derived from the patient's phenotypically normal mother also demonstrated the presence of a ring 19 chromosome in 4/100 cells. The remaining cells had a normal female chromosome complement. These findings represent the first reported case of familial ring 19 mosaicism. The cytogenetic and clinical findings in these two individuals are discussed in relation to six previously reported cases of de novo ring chromosome 19 mosaicism.     

A stingray spine in the scapula of a bottlenose dolphin

A stingray spine was found lodged in the scapula of a deceased 272 cm, male bottlenose dolphin (Tursiops truncatus) from South Carolina (USA) following skeletal preparation, nearly 6 mo after necropsy. No external puncture wound, internal bruising, or laceration of muscle tissue surrounding the scapula was evident during necropsy of the animal. Implantation of the spine did not appear to be related to the death of the dolphin, but probably occurred at an early age. Abnormal development of bone surrounding the spine resulted in the formation of a cavity at the wound site. Two mechanisms were considered as contributors for the cavity formation. These were the mechanical action of the spine stimulating the body's defense system for managing foreign objects, and the release of potent toxins from the spine sheath.     

Thermally and plastically induced residual strains in textured Zircaloy-2 plate

The residual intergranular strains in textured Zircaloy-2 plate samples induced by cooling from 823 K to ambient temperatures, by cold-rolling by 1.5% and 25% and by deforming in tension by 1.5% were measured by neutron diffraction. The strong rolling texture, which gives rise to two ideal orientations, permitted the interpretation of much of the data in terms of strain tensors for the two orientations. The experimental results were compared with calculations based on the elasto-plastic self-consistent model with no adjustable parameters. Close agreement was obtained for samples in the as-cooled state and deformation in tension by 1.5% but the agreement is less satisfactory for cold-rolling.     

Insights into the industrial growth of cyanobacteria from a model of the carbon‐concentrating mechanism

With the advent of modern bioengineering tools, photosynthetic organisms are increasingly being engineered to produce chemicals from CO₂ sources, thereby creating a potential route of sustainable chemical production. Cyanobacteria have evolved a carbon‐concentrating mechanism (CCM) that enables growth at low‐environmental carbon concentrations. However at high‐carbon concentrations these benefits may not outweigh synthesis costs. Here, mass transport and kinetic modeling analyses were performed on two species of cyanobacteria as well as a hypothetical no‐CCM mutant. Modeling results correlated with published experimental data. Three conclusions were drawn from the analysis. Carboxysome geometry was unimportant due to the fast relative rate of diffusion of carbon species. Interspecies variations were largely due to active transporters. The no‐carboxysome cell approaches the wild‐type at 10% CO₂. Therefore, in high CO₂ environments the carboxysome and active bicarbonate transporters provide no benefit and a metabolic advantage could be achieved by eliminating the energy‐intensive CCM proteins. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1269–1277, 2014     

Quantitative RP-HPLC Determination of Some Aldehydes and Hydroxyaldehydes as Their 2,4-Dinitrophenylhydrazone Derivatives

A high-performance liquid chromatographic (HPLC) method is described for the quantitative determination of some aliphatic aldehydes and β-hydroxyaldehydes as their 2,4-dinitrophenylhydrazone derivatives. A method is described for the preparation of derivatives for those β-hydroxyaldehydes where no reference compounds of known purity are available. The detection limit of the method was 4.3-21.0 μg/L, depending on the aldehyde.