Shedding light on predicting and controlling emission chromaticity in multicomponent photoluminescent systems.

Predictable colour tuning in multicomponent photoluminescent (PL) systems is achieved using mixtures of simultaneously emitting organic molecules. By mitigating the potential for energy transfer through the control of concentration, the resulting emission chromaticity of five dichromic PL systems is approximated as a linear combination of the emitting components and their corresponding brightness (χ i , ϕ i , and I ex,i ). Despite being limited to dilute solutions (10-6 M), colour tuning within these systems was controlled by (1) varying the composition of the components and (2) exploiting the differences in the components' excitation intensities at common wavelengths. Using this approach, white light emission (WLE) was realized using a pre-determined mixture of red, green, and blue emitting organic molecules. Based on these results, materials and devices with built-in or programmable emission colour can be achieved, including highly sought-after WLE.

Microwave-assisted activation and modulator removal in zirconium MOFs for buffer-free CWA hydrolysis.

A novel, facile and efficient method was developed for the activation of acetic acid modulated zirconium MOFs. The protocol involves briefly heating the material in water using microwave irradiation. MOF-808, DUT-84 and UiO-66 were all activated in this manner to remove the modulator and organic solvent from the framework post synthesis, with retention of MOF integrity post activation. The degree of activation was characterised by the use of TGA and NMR. The catalytic activity of the activated MOFs and their non-activated counterparts was investigated for chemical warfare agent (CWA) hydrolysis. Upon activation, an increase in the rate of hydrolysis was observed in the degradation of CWA simulant dimethyl 4-nitrophenyl phosphate (DMNP). MOF-808 and DUT-84 were also screened as catalysts for the hydrolysis of the V-series agent VM, with remarkable half-lives obtained for MOF-808 in the absence of any buffers. Currently employed MOF activation procedures involve the use of additional organic solvents post synthesis; we believe this method to be ideally efficacious for the organic desolvation of zirconium MOFs and removing modulator additives.

Alkaline-earth phosphonate MOFs with reversible hydration-dependent fluorescence.

A new rigid tritopic phosphonic ligand, 2,4,6-tris(4-phosphonophenyl)pyridine (H6L), was synthesized and used to assemble isostructural barium (1) and strontium (2) phosphonate metal organic frameworks that exhibit fully reversible and selective water-dependent fluorescence red-shift at room temperature.

Sensing a Bacillis anthracis biomarker with well-known OLED emitter EuTta3Phen.

Dipicolinic acid (DPA) is a distinctive biomarker for bacterial spores. Here, we present the successful demonstration of dramatic Switch-OFF sensing of DPA using an easily synthesised Eu(iii) phosphor applied primarily in light-emitting devices. The sensor in the presence of water and phosphate is also demonstrated to be effective.

Fiber levels and disease in workers from a factory predominantly using amosite.

The Cape Boards Plant at Uxbridge produced insulation board containing amosite asbestos between 1947 and 1973 with only small amounts of chrysotile. After 1973 only amosite was used. In this study we examined lung samples from 48 workers who had been employed at the plant and who had come to autopsy. The study investigated the fiber levels against the lung pathology including amount of interstitial fibrosis and numbers of ferruginous bodies. The degree of interstitial fibrosis and number of asbestos bodies were graded and the tissues were analyzed by transmission electron microscopy and energy dispersive X-ray analysis and the fibers counted and typed. The 48 cases included 5 mesotheliomas and 14 lung cancers. The mineral analysis results were dominated by the amosite fiber levels. The amounts of chrysotile were relatively small. There were higher levels in lung cancer cases than mesotheliomas and higher levels in mesothelioma cases than those who had died from nonasbestos related diseases. Analysis of the lung tissues showed a consistent pattern of high amosite levels, which confirms the impression that amosite was the predominant form of asbestos used and also indicates that the factory had been a very dusty one.

Fibre distribution in the lungs and pleura of subjects with asbestos related diffuse pleural fibrosis.

The lungs from 13 cases of diffuse pleural fibrosis associated with a history of exposure to asbestos were examined. Samples were taken from the visceral pleura and central and subpleural zones of the lungs for histopathological and mineralogical studies. The fibre type, size, and number were estimated for each of these regions by transmission electron microscopy and energy dispersive x ray analysis. Amphibole fibre counts were raised when compared with a non-occupationally exposed group and matched those seen in cases of pleural plaques, mild asbestosis, and mesothelioma. A wide case to case variation of distribution was seen. No significant difference was apparent between central and subpleural zones, whereas low asbestos counts were found in the pleura; these were mainly short chrysotile fibres. Within the lungs more (45%) of the longer (greater than 4 microns) and thinner (less than 0.25 micron) amphibole fibres were retained in keeping with other studies implicating such fibre profiles in the pathogenesis of asbestos related disease.

A Bayesian change-point problem with an application to the prediction and detection of ovulation in women.

Under the assumptions of independent normally distributed and sequentially observed responses, a Bayesian rule for detecting a change from a constant mean response is derived. It is known that both basal body temperature (BBT) and preovulatory estrogen values undergo such a change in mean value at some random time during the menstrual cycle. The Bayesian rule is applied to estrogen to predict ovulation and to BBT to detect ovulation. Data from an aggregate of women are used to obtain prior information about the change-points and the parameters that define the changes in estrogen and BBT. A method is proposed by which the accumulation of information for a specific women can be incorporated into the aggregate prior information.

PIP: For most normally menstruating women, the sequence of hormonal events leading up to and following occurrence of ovulation is the same. Rise in estrogen induces a midcycle surge of luteinizing hormone (LH) to a peak, followed by ovulation and then a sharp rise in plasma progesterone which in turn increases basal body temperature (BBT) to a higher level. Therefore, detection of change-points in estrogen and BBT can help predict and detect ovulation. This paper presents sequential Bayesian solutions to the problems of detecting changes in both estrogen and BBT under assumptions of independent normally distributed and sequentially observed responses. The Bayesian solutions are applied to an aggregate of women who were observed throughout their menstrual cycles. In 33 women, ovulation was predicted in advance of the LH peak, and thus in advance of the actual ovulation. Ovulation was predicted an average of 3.55 days prior to the LH peak with a standard deviation of 1.46 days. In another 41 women, BBT observations were taken during 1 menstrual cycle; in 38 of these women, BBT shift was detected after it had occurred, the detection occurring at an average of 2.58 days after the change point with a standard deviation of 1.31 days where the change point is the day prior to the rise in BBT. In 24 women for whom change points in both estrogen and BBT were detected, a midcycle 'fertile period' can be marked off; average length of the 'fertile period' was 7.38 days with a standard deviation of 1.81 days. All women had length or= to 11 days. A method is proposed by which the accumulation of information for a specific woman can be incorporated into the aggregate prior information.

An assessment of serum 57Co cyanocobalamin as an index of vitamin B12 absorption.

A technique has been developed for accurately assaying serum and urine (57)Co cyanocobalamin during the conventional Schilling test. Serum and urine radioactivity in a large number of patients has been correlated and the precise normal limits have been determined by statistical analysis. The implications of this for investigating conditions other than pernicious anaemia and the malabsorption syndromes are stressed.