VUV emission and absorption spectroscopy with a multichannel near normal incidence spectrometer

An experiment for vacuum UV emission and photoabsorption spectroscopy usmg a normal incidence multi-channel spectrometer is described. Two detection configurations were used in the experiments, one a Channel Electron Multiplier Anay with Photo Diode Array readout ( CEMA / PDA), the other a directly illuminated back thmned Charge Coupled Device ( CCD ). Emission spectra of plasmas of a number of low and high Z target matenals were recorded covering the majority of the vacuum UV spectral region ( 35 to 200 nm ). These experiments were designed mainly to study the nature of the emission ( line versus continuum) and it’s dependence on atomic number. The use of two detection configurations allowed for mter comparisons to be made on resolution, efficiency and dynamic range of the two multi-channel detector and spectrometer systems. Experiments were also performed on photoabsorption by helium gas. The spectra thus obtamed were used to help charactense the system’s application to absorption studies around the He principal series limit at - 50 43 nm. In addition, for the first time the instrument was used to study photoabsorption using the dual laser plasma technique ( DLP ). Results on the relative photo absorption cross sections of barium and barium ions using a samarium continuum back-light are presented which indicate that the instrument is well suited to absorption experiments m the range of 35 to 80 nm where second order of the contmuum is mainly absent and the grating is being used close to it’s blaze wavelength ( 80 nm ). Finally, the work concludes with details on the design, construction and preliminary testmg of a vacuum-optical beamlme which should both improve the aperture matchmg ability of the instrument and allow spatially resolved studies of the laser plasma light source to be made. The spectrometer with the additional spherical mirror was modelled by means of simple geometric optic calculations as well as with ray tracing software m order to estimate improvements in throughput

A Rapid and Sensitive Method for Measuring NAcetylglucosaminidase Activity in Cultured Cells

A rapid and sensitive method to quantitatively assess N-acetylglucosaminidase (NAG) activity in cultured cells is highly desirable for both basic research and clinical studies. NAG activity is deficient in cells from patients with Mucopolysaccharidosis type IIIB (MPS IIIB) due to mutations in NAGLU, the gene that encodes NAG. Currently available techniques for measuring NAG activity in patient-derived cell lines include chromogenic and fluorogenic assays and provide a biochemical method for the diagnosis of MPS IIIB. However, standard protocols require large amounts of cells, cell disruption by sonication or freeze-thawing, and normalization to the cellular protein content, resulting in an error-prone procedure that is material- and time-consuming and that produces highly variable results. Here we report a new procedure for measuring NAG activity in cultured cells. This procedure is based on the use of the fluorogenic NAG substrate, 4- Methylumbelliferyl-2-acetamido-2-deoxy-alpha-D-glucopyranoside (MUG), in a one-step cell assay that does not require cell disruption or post-assay normalization and that employs a low number of cells in 96-well plate format. We show that the NAG one-step cell assay greatly discriminates between wild-type and MPS IIIB patient-derived fibroblasts, thus providing a rapid method for the detection of deficiencies in NAG activity. We also show that the assay is sensitive to changes in NAG activity due to increases in NAGLU expression achieved by either overexpressing the transcription factor EB (TFEB), a master regulator of lysosomal function, or by inducing TFEB activation chemically. Because of its small format, rapidity, sensitivity and reproducibility, the NAG one-step cell assay is suitable for multiple procedures, including the high-throughput screening of chemical libraries to identify modulators of NAG expression, folding and activity, and the investigation of candidate molecules and constructs for applications in enzyme replacement therapy, gene therapy, and combination therapies

Ancillary human health benefits of improved air quality resulting from climate change mitigation

<p>Abstract</p> <p>Background</p> <p>Greenhouse gas (GHG) mitigation policies can provide ancillary benefits in terms of short-term improvements in air quality and associated health benefits. Several studies have analyzed the ancillary impacts of GHG policies for a variety of locations, pollutants, and policies. In this paper we review the existing evidence on ancillary health benefits relating to air pollution from various GHG strategies and provide a framework for such analysis.</p> <p>Methods</p> <p>We evaluate techniques used in different stages of such research for estimation of: (1) changes in air pollutant concentrations; (2) avoided adverse health endpoints; and (3) economic valuation of health consequences. The limitations and merits of various methods are examined. Finally, we conclude with recommendations for ancillary benefits analysis and related research gaps in the relevant disciplines.</p> <p>Results</p> <p>We found that to date most assessments have focused their analysis more heavily on one aspect of the framework (e.g., economic analysis). While a wide range of methods was applied to various policies and regions, results from multiple studies provide strong evidence that the short-term public health and economic benefits of ancillary benefits related to GHG mitigation strategies are substantial. Further, results of these analyses are likely to be underestimates because there are a number of important unquantified health and economic endpoints.</p> <p>Conclusion</p> <p>Remaining challenges include integrating the understanding of the relative toxicity of particulate matter by components or sources, developing better estimates of public health and environmental impacts on selected sub-populations, and devising new methods for evaluating heretofore unquantified and non-monetized benefits.</p

Stable or improved neurological manifestations during miglustat therapy in patients from the international disease registry for Niemann-Pick disease type C: an observational cohort study

Background: Niemann-Pick disease type C (NP-C) is a rare neurovisceral disease characterised by progressive neurological degeneration, where the rate of neurological disease progression varies depending on age at neurological onset. We report longitudinal data on functional disease progression and safety observations in patients in the international NPC Registry who received continuous treatment with miglustat. Methods: The NPC Registry is a prospective observational cohort of NP-C patients. Enrolled patients who received ≥1 year of continuous miglustat therapy (for ≥90 % of the observation period, with no single treatment interruption >28 days) were included in this analysis. Disability was measured using a scale rating the four domains, ambulation, manipulation, language and swallowing from 0 (normal) to 1 (worst). Neurological disease progression was analysed in all patients based on: 1) annual progression rates between enrolment and last follow up, and; 2) categorical analysis with patients categorised as 'improved/stable' if ≥3/4 domain scores were lower/unchanged, and as 'progressed' if <3 scores were lower/unchanged between enrolment and last follow-up visit. Results: In total, 283 patients were enrolled from 28 centers in 13 European countries, Canada and Australia between September 2009 and October 2013; 92 patients received continuous miglustat therapy. The mean (SD) miglustat exposure during the observation period (enrolment to last follow-up) was 2.0 (0.7) years. Among 84 evaluable patients, 9 (11 %) had early-infantile (<2 years), 27 (32 %) had late-infantile (2 to <6 years), 30 (36 %) had juvenile (6 to <15 years) and 18 (21 %) had adolescent/adult (≥15 years) onset of neurological manifestations. The mean (95%CI) composite disability score among all patients was 0.37 (0.32,0.42) at enrolment and 0.44 (0.38,0.50) at last follow-up visit, and the mean annual progression rate was 0.038 (0.018,0.059). Progression of composite disability scores appeared highest among patients with neurological onset during infancy or childhood and lowest in those with adolescent/adult-onset. Overall, 59/86 evaluable patients (69 %) were categorized as improved/stable and the proportion of improved/stable patients increased with age at neurological onset. Safety findings were consistent with previous data. Conclusions: Disability status was improved/stable in the majority of patients who received continuous miglustat therapy for an average period of 2 years

VUV emission and absorption spectroscopy with a multichannel near normal incidence spectrometer

An experiment for vacuum UV emission and photoabsorption spectroscopy usmg a normal incidence multi-channel spectrometer is described. Two detection configurations were used in the experiments, one a Channel Electron Multiplier Anay with Photo Diode Array readout ( CEMA / PDA), the other a directly illuminated back thmned Charge Coupled Device ( CCD ). Emission spectra of plasmas of a number of low and high Z target matenals were recorded covering the majority of the vacuum UV spectral region ( 35 to 200 nm ). These experiments were designed mainly to study the nature of the emission ( line versus continuum) and it’s dependence on atomic number. The use of two detection configurations allowed for mter comparisons to be made on resolution, efficiency and dynamic range of the two multi-channel detector and spectrometer systems. Experiments were also performed on photoabsorption by helium gas. The spectra thus obtamed were used to help charactense the system’s application to absorption studies around the He principal series limit at - 50 43 nm. In addition, for the first time the instrument was used to study photoabsorption using the dual laser plasma technique ( DLP ). Results on the relative photo absorption cross sections of barium and barium ions using a samarium continuum back-light are presented which indicate that the instrument is well suited to absorption experiments m the range of 35 to 80 nm where second order of the contmuum is mainly absent and the grating is being used close to it’s blaze wavelength ( 80 nm ). Finally, the work concludes with details on the design, construction and preliminary testmg of a vacuum-optical beamlme which should both improve the aperture matchmg ability of the instrument and allow spatially resolved studies of the laser plasma light source to be made. The spectrometer with the additional spherical mirror was modelled by means of simple geometric optic calculations as well as with ray tracing software m order to estimate improvements in throughput

Bacteria of Dental Caries in Primary and Permanent Teeth in Children and Young Adults▿

Although Streptococcus mutans has been implicated as a major etiological agent of dental caries, our cross-sectional preliminary study indicated that 10% of subjects with rampant caries in permanent teeth do not have detectable levels of S. mutans. Our aims were to use molecular methods to detect all bacterial species associated with caries in primary and permanent teeth and to determine the bacterial profiles associated with different disease states. Plaque was collected from 39 healthy controls and from intact enamel and white-spot lesions, dentin lesions, and deep-dentin lesions in each of 51 subjects with severe caries. 16S rRNA genes were PCR amplified, cloned, and sequenced to determine species identities. In a reverse-capture checkerboard assay, 243 samples were analyzed for 110 prevalent bacterial species. A sequencing analysis of 1,285 16S rRNA clones detected 197 bacterial species/phylotypes, of which 50% were not cultivable. Twenty-two new phylotypes were identified. PROC MIXED tests revealed health- and disease-associated species. In subjects with S. mutans, additional species, e.g., species of the genera Atopobium, Propionibacterium, and Lactobacillus, were present at significantly higher levels than those of S. mutans. Lactobacillus spp., Bifidobacterium dentium, and low-pH non-S. mutans streptococci were predominant in subjects with no detectable S. mutans. Actinomyces spp. and non-S. mutans streptococci were predominant in white-spot lesions, while known acid producers were found at their highest levels later in disease. Bacterial profiles change with disease states and differ between primary and secondary dentitions. Bacterial species other than S. mutans, e.g., species of the genera Veillonella, Lactobacillus, Bifidobacterium, and Propionibacterium, low-pH non-S. mutans streptococci, Actinomyces spp., and Atopobium spp., likely play important roles in caries progression