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Sample records for breakdown product biomarkers

  1. Spillway-induced salmon head injury triggers the generation of brain alphaII-spectrin breakdown product biomarkers similar to mammalian traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Ann Miracle

    Full Text Available Recent advances in biomedical research have resulted in the development of specific biomarkers for diagnostic testing of disease condition or physiological risk. Of specific interest are alphaII-spectrin breakdown products (SBDPs, which are produced by proteolytic events in traumatic brain injury and have been used as biomarkers to predict the severity of injury in humans and other mammalian brain injury models. This study describes and demonstrates the successful use of antibody-based mammalian SBDP biomarkers to detect head injury in migrating juvenile Chinook salmon (Oncorhynchus tshawytscha that have been injured during passage through high-energy hydraulic environments present in spillways under different operational configurations. Mortality and injury assessment techniques currently measure only near-term direct mortality and easily observable acute injury. Injury-based biomarkers may serve as a quantitative indicator of subacute physical injury and recovery, and aid hydropower operators in evaluation of safest passage configuration and operation actions for migrating juvenile salmonids. We describe a novel application of SBDP biomarkers for head injury for migrating salmon. To our knowledge, this is the first documented cross-over use of a human molecular biomarker in a wildlife and operational risk management scenario.

  2. Semantic tags for generative multiview product breakdown

    OpenAIRE

    Paviot, Thomas; Cheutet, Vincent; Lamouri, Samir

    2010-01-01

    The interoperability of IT systems that drive engineering and production processes (i.e. Product Data Management and Enterprise Resource Planning systems) is still an issue. The semantic meaning of product information has to be explicit in order to be able to exchange information between these systems. However, the product breakdown activity generates many disconnected product views over which the product semantics is disseminated and mostly implicit. This paper introduces a methodology allow...

  3. Metabolic products as biomarkers

    Science.gov (United States)

    Melancon, M.J.; Alscher, R.; Benson, W.; Kruzynski, G.; Lee, R.F.; Sikka, H.C.; Spies, R.B.; Huggett, Robert J.; Kimerle, Richard A.; Mehrle, Paul M.=; Bergman, Harold L.

    1992-01-01

    Ideally, endogenous biomarkers would indicate both exposure and environmental effects of toxic chemicals; however, such comprehensive biochemical and physiological indices are currently being developed and, at the present time, are unavailable for use in environmental monitoring programs. Continued work is required to validate the use of biochemical and physiological stress indices as useful components of monitoring programs. Of the compounds discussed only phytochelatins and porphyrins are currently in biomarkers in a useful state; however, glutathione,metallothioneins, stress ethylene, and polyamines are promising as biomarkers in environmental monitoring.

  4. Development of Hybrid Product Breakdown Structure for NASA Ground Systems

    Science.gov (United States)

    Monaghan, Mark W.; Henry, Robert J.

    2013-01-01

    The Product Breakdown Structure is traditionally a method of identification of the products of a project in a tree structure. It is a tool used to assess, plan, document, and display the equipment requirements for a project. It is part of a product based planning technique, and attempts to break down all components of a project in as much detail as possible, so that nothing is overlooked. The PBS for ground systems at the Kennedy Space Center is being developed to encompass the traditional requirements including the alignment of facility, systems, and components to the organizational hierarchy. The Ground Operations Product Breakdown Structure is a hybrid in nature in that some aspects of a work breakdown structure will be incorporated and merged with the Architecture Concept of Operations, Master Subsystem List, customer interface, and assigned management responsibility. The Ground Operations Product Breakdown Structure needs to be able to identify the flexibility of support differing customers (internal and external) usage of ground support equipment within the Kennedy Space Center launch and processing complex. The development of the Product Breakdown Structure is an iterative activity Initially documenting the organization hierarchy structure and relationships. The Product Breakdown Structure identifies the linkage between the customer program requirements, allocation of system resources, development of design goals, and identification logistics products. As the Product Breakdown Structure progresses the incorporation of the results of requirement planning for the customer occurs identifying facility needs and systems. The mature Product Breakdown Structure is baselined with a hierarchical drawing, the Product Breakdown Structure database, and an associated document identifying the verification of the data through the life cycle of the program/product line. This paper will document, demonstrate, and identify key aspects of the life cycle of a Hybrid Product

  5. AVLIS Production Plant work breakdown structure and Dictionary

    Energy Technology Data Exchange (ETDEWEB)

    1984-11-15

    The work breakdown structure has been prepared for the AVLIS Production Plant to define, organize, and identify the work efforts and is summarized in Fig. 1-1 for the top three project levels. The work breakdown structure itself is intended to be the primary organizational tool of the AVLIS Production Plant and is consistent with the overall AVLIS Program Work Breakdown Structure. It is designed to provide a framework for definition and accounting of all of the elements that are required for the eventual design, procurement, and construction of the AVLIS Production Plant. During the present phase of the AVLIS Project, the conceptual engineering phase, the work breakdown structure is intended to be the master structure and project organizer of documents, designs, and cost estimates. As the master project organizer, the key role of the work breakdown structure is to provide the mechanism for developing completeness in AVLIS cost estimates and design development of all hardware and systems. The work breakdown structure provides the framework for tracking, on a one-to-one basis, the component design criteria, systems requirements, design concepts, design drawings, performance projections, and conceptual cost estimates. It also serves as a vehicle for contract reporting. 12 figures, 2 tables.

  6. AVLIS Production Plant work breakdown structure and Dictionary

    International Nuclear Information System (INIS)

    The work breakdown structure has been prepared for the AVLIS Production Plant to define, organize, and identify the work efforts and is summarized in Fig. 1-1 for the top three project levels. The work breakdown structure itself is intended to be the primary organizational tool of the AVLIS Production Plant and is consistent with the overall AVLIS Program Work Breakdown Structure. It is designed to provide a framework for definition and accounting of all of the elements that are required for the eventual design, procurement, and construction of the AVLIS Production Plant. During the present phase of the AVLIS Project, the conceptual engineering phase, the work breakdown structure is intended to be the master structure and project organizer of documents, designs, and cost estimates. As the master project organizer, the key role of the work breakdown structure is to provide the mechanism for developing completeness in AVLIS cost estimates and design development of all hardware and systems. The work breakdown structure provides the framework for tracking, on a one-to-one basis, the component design criteria, systems requirements, design concepts, design drawings, performance projections, and conceptual cost estimates. It also serves as a vehicle for contract reporting. 12 figures, 2 tables

  7. Measurement of the glial fibrillary acidic protein and its breakdown products GFAP-BDP biomarker for the detection of traumatic brain injury compared to computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    McMahon, Paul J; Panczykowski, David M; Yue, John K; Puccio, Ava M; Inoue, Tomoo; Sorani, Marco D; Lingsma, Hester F; Maas, Andrew I R; Valadka, Alex B; Yuh, Esther L; Mukherjee, Pratik; Manley, Geoffrey T; Okonkwo, David O

    2015-04-15

    Glial fibrillary acidic protein and its breakdown products (GFAP-BDP) are brain-specific proteins released into serum as part of the pathophysiological response after traumatic brain injury (TBI). We performed a multi-center trial to validate and characterize the use of GFAP-BDP levels in the diagnosis of intracranial injury in a broad population of patients with a positive clinical screen for head injury. This multi-center, prospective, cohort study included patients 16-93 years of age presenting to three level 1 trauma centers with suspected TBI (loss of consciousness, post-trauma amnesia, and so on). Serum GFAP-BDP levels were drawn within 24 h and analyzed, in a blinded fashion, using sandwich enzyme-linked immunosorbent assay. The ability of GFAP-BDP to predict intracranial injury on admission computed tomography (CT) as well as delayed magnetic resonance imaging was analyzed by multiple regression and assessed by the area under the receiver operating characteristic curve (AUC). Utility of GFAP-BDP to predict injury and reduce unnecessary CT scans was assessed utilizing decision curve analysis. A total of 215 patients were included, of which 83% suffered mild TBI, 4% moderate, and 12% severe; mean age was 42.1±18 years. Evidence of intracranial injury was present in 51% of the sample (median Rotterdam Score, 2; interquartile range, 2). GFAP-BDP demonstrated very good predictive ability (AUC=0.87) and demonstrated significant discrimination of injury severity (odds ratio, 1.45; 95% confidence interval, 1.29-1.64). Use of GFAP-BDP yielded a net benefit above clinical screening alone and a net reduction in unnecessary scans by 12-30%. Used in conjunction with other clinical information, rapid measurement of GFAP-BDP is useful in establishing or excluding the diagnosis of radiographically apparent intracranial injury throughout the spectrum of TBI. As an adjunct to current screening practices, GFAP-BDP may help avoid unnecessary CT scans without sacrificing

  8. Bioavailability of Glucosinolates and Their Breakdown Products: Impact of Processing.

    Science.gov (United States)

    Barba, Francisco J; Nikmaram, Nooshin; Roohinejad, Shahin; Khelfa, Anissa; Zhu, Zhenzhou; Koubaa, Mohamed

    2016-01-01

    Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability. PMID:27579302

  9. Bioavailability of Glucosinolates and Their Breakdown Products: Impact of Processing

    Science.gov (United States)

    Barba, Francisco J.; Nikmaram, Nooshin; Roohinejad, Shahin; Khelfa, Anissa; Zhu, Zhenzhou; Koubaa, Mohamed

    2016-01-01

    Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability. PMID:27579302

  10. Analysis of bakery products by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Bilge, Gonca; Boyacı, İsmail Hakkı; Eseller, Kemal Efe; Tamer, Uğur; Çakır, Serhat

    2015-08-15

    In this study, we focused on the detection of Na in bakery products by using laser-induced breakdown spectroscopy (LIBS) as a quick and simple method. LIBS experiments were performed to examine the Na at 589 nm to quantify NaCl. A series of standard bread sample pellets containing various concentrations of NaCl (0.025-3.5%) were used to construct the calibration curves and to determine the detection limits of the measurements. Calibration graphs were drawn to indicate functions of NaCl and Na concentrations, which showed good linearity in the range of 0.025-3.5% NaCl and 0.01-1.4% Na concentrations with correlation coefficients (R(2)) values greater than 0.98 and 0.96. The obtained detection limits for NaCl and Na were 175 and 69 ppm, respectively. Performed experimental studies showed that LIBS is a convenient method for commercial bakery products to quantify NaCl concentrations as a rapid and in situ technique.

  11. Microbial conversion of selected azo dyes and their breakdown products.

    Science.gov (United States)

    Yemashova, N; Kalyuzhnyi, S

    2006-01-01

    Four selected azo dyes (acid orange 6, acid orange 7, methyl orange and methyl red) were completely decolourised in the presence of anaerobic granular sludge, while only methyl red was degraded in aerobic conditions using a conventional activated sludge. Additional experiments with culture broth devoid of cells showed that anaerobic decolourisation of azo dyes was performed by extracellular reducing agents produced by anaerobic bacteria. This was further confirmed by abiotic experiments with sulphide and NADH. The presence of redox mediators such as riboflavin led to dramatic acceleration of the anaerobic biodecolourisation process. The azo dye reduction products were found to be sulphanilic acid and 4-aminoresorcinol for acid orange 6; sulphanilic acid and 1-amino-2-naphthol for acid orange 7; N,N-dimethyl-1,4-phenylenediamine and sulphanilic acid for methyl orange; and N,N-dimethyl-1,4-phenylenediamine and anthranilic acid for methyl red. Anaerobic toxicity assays showed that the azo dyes were more toxic than their breakdown products (aromatic amines), except 1-amino-2-naphthol. In the presence of activated sludge, only anthranilic acid was completely mineralised while sulphanilic acid was persistent. 4-aminoresorcinol, 1-amino-2-naphthol and N,N-dimethyl-1,4-phenylenediamine underwent autooxidation in aerobic conditions yielding coloured polymeric products. On the contrary, in the presence of granular methanogenic sludge, 4-aminoresorcinol, 1-amino-2-naphthol and anthranilic acid were quantitatively methanised, sulphanilic acid was partially (70%) mineralised while N,N-dimethyl-1,4-phenylenediamine was only demethylated producing 1,4-phenylenediamine as an end product.

  12. Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation

    OpenAIRE

    Stettler, Michaela; Eicke, Simona; Mettler, Tabea; Messerli, Gaëlle; Hörtensteiner, Stefan; Zeeman, Samuel C.

    2009-01-01

    In most plants, a large fraction of photo-assimilated carbon is stored in the chloroplasts during the day as starch and remobilized during the subsequent night to support metabolism. Mutations blocking either starch synthesis or starch breakdown in Arabidopsis thaliana reduce plant growth. Maltose is the major product of starch breakdown exported from the chloroplast at night. The maltose excess 1 mutant (mex1), which lacks the chloroplast envelope maltose transporter, accumulates high levels...

  13. Allelopathic effects of glucosinolate breakdown products in Hanza [Boscia senegalensis (Pers.) Lam.] processing waste water

    OpenAIRE

    Rivera-Vega, Loren J.; Krosse, Sebastian; de Graaf, Rob M; Garvi, Josef; Garvi-Bode, Renate D.; van Dam, Nicole M.

    2015-01-01

    Boscia senegalensis is a drought resistant shrub whose seeds are used in West Africa as food. However, the seeds, or hanza, taste bitter which can be cured by soaking them in water for 4–7 days. The waste water resulting from the processing takes up the bitter taste, which makes it unsuitable for consumption. When used for irrigation, allelopathic effects were observed. Glucosinolates and their breakdown products are the potential causes for both the bitter taste and the allelopathic effects....

  14. Mathematical models for process commonality under quality and resources breakdown in multistage production

    Institute of Scientific and Technical Information of China (English)

    Mohammed Abdul WAZED; Shamsuddin AHMED; Yusoff Bin NUKMANt

    2011-01-01

    It is essential to manage customers' diverse desires and to keep manufacturing costs as low as possible for survival in competition and eventually in production.Sharing resources in manufacturing for different products is a vital method of accomplishing this goal.The advantages of using a common process in production are stated in the literature.However,the mathematical models as well as simulation or conceptual models are not sufficient.The main objective of this paper is to develop mathematical models for multiproduct and multistage production under quality and breakdown uncertainties.The idea of the process commonality is incorporated in the proposed models.The models are validated by primary data collected from a Malaysian company and comparison of the timely requirement schedules of earlier MRP Ⅱ and the proposed models under stable and perfect production environments.An appreciable convergence of the outcomes is observed.However,the proposed models are carrying additional information about the available locations of the parts in a time frame.After validation,the effects of process commonality on cost,capacity and the requirement schedule under uncertainties are examined.It is observed that the use of common processes in manufacturing is always better than the non-commonality scenario in terms of production cost.However,the increase in capacity requirement for commonality designs is higher for an ideal system,while it is less when the system suffers from breakdowns and a quality problem.

  15. A comparison of push and pull production controls under machine breakdown

    Directory of Open Access Journals (Sweden)

    Prakash, J.

    2011-01-01

    Full Text Available Production control for high-mix production remains a complex issue. Common pull system replenishment generates large works-in-process (WIPs for each part type, especially under breakdown. This paper attempts to solve this by presenting a production control that classifies parts into two categories. The performances of three production control mechanisms under breakdown are compared. The production control mechanisms in consideration are push, shared constant WIP (CONWIP, and parallel CONWIP. A full-factorial simulation experiment was conducted. ANOVA was performed to determine the significant effects of input factors. Response surface methodology was used to demonstrate the behavior of performance measures in terms of these significant input factors. The results prove that parallel CONWIP is superior over shared CONWIP in terms of the average flow time per part. If categorical dispatch rules are employed, parallel CONWIP outperforms shared CONWIP in terms of service level. With high card count, parallel CONWIP generally produces lower bottleneck utilizations while maintaining a low average flow time per part than shared CONWIP.

  16. Glucosinolate breakdown products as insect fumigants and their effect on carbon dioxide emission of insects

    Directory of Open Access Journals (Sweden)

    Coats Joel R

    2002-03-01

    Full Text Available Abstract Background Glucosinolate breakdown products are volatile, therefore good candidates for insect fumigants. However, although they are insecticidal, the mode of action of such natural products is not clear. We studied the insecticidal effect of these compounds as fumigants, and monitored the production of carbon dioxide by the insects as a probe to the understanding of their mode of action. Results The fumigation 24-h LC50 against the house fly (Musca domestica L. of allyl thiocyanate, allyl isothiocyanate, allyl cyanide, and l-cyano-2-hydroxy-3-butene was 0.1, 0.13, 3.66, and 6.2 μg cm-3, respectively; they were 0.55, 1.57, 2.8, and > 19.60 μg cm-3, respectively, against the lesser grain borer (Rhyzopertha dominica Fabricius. The fumigation toxicity of some of the glucosinolate products was very close to or better than that of the commercial insect fumigants such as chloropicrin (LC50: 0.08 and 1.3 μg cm-3 against M. domestica and R. dominica, respectively and dichlorovos (LC50: -3 against M. domestica and R. dominica, respectively in our laboratory tests. Significantly increased CO2 expiration was found in insects exposed to the vapor of allyl isothiocyanate, allyl thiocyanate and allyl isocyanate. Allyl isothiocyanate was also found to increase the CO2 expiration of the American cockroach (Periplaneta americana L.. Conclusions Glucosinolate breakdown products have potential as biodegradable and safe insect fumigants. They may act on the insect respiratory system in their mode of action.

  17. Urine products of bone breakdown as markers of bone resorption and clinical usefulness of urinary hydroxyproline:an overview

    Institute of Scientific and Technical Information of China (English)

    Baris Simsek; (O)zgul Karacaer; inci Karaca

    2004-01-01

    Purpose The purpose of this study is to review the urine products of bone breakdown as markers of bone resorption and usefulness of urinary hydroxyproline. Data Related researches published in 1985 -2000 were systematically reviewed. Results Bone markers could be used for early diagnosis of bone metabolic diseases. Biochemical markers of bone resorption that reflect osteoclast activity and/or collagen degradation provide a new and potentially important clinical tool for the assessment and monitoring of bone metabolism. Assessment of bone resorption can be achieved with measurement of urinary hydroxylysine glycosides, urinary excretion of the collagen pyridinium cross-links, urinary excretion of type I collagen telopeptide breakdown products (cross-linked telopeptides) and urinary hydroxyproline. Conclusion Urinary hydroxyproline has been in use as a marker of bone resorption, but it lacks sensitivity and specificity. It is a modified aminoacid that is a metabolic product of collagen breakdown.Hydroxyproline may be released either free or with fragments of the collagen molecule attached during bone resorption, and it is also liberated by the breakdown of complement and nonskeletal collagen.

  18. Serum Glial Fibrillary Acidic Protein Predicts Tissue Glial Fibrillary Acidic Protein Break-Down Products and Therapeutic Efficacy after Penetrating Ballistic-Like Brain Injury.

    Science.gov (United States)

    Boutté, Angela M; Deng-Bryant, Ying; Johnson, David; Tortella, Frank C; Dave, Jitendra R; Shear, Deborah A; Schmid, Kara E

    2016-01-01

    Acute traumatic brain injury (TBI) is associated with neurological dysfunction, changes in brain proteins, and increased serum biomarkers. However, the relationship between these brain proteins and serum biomarkers, and the ability of these serum biomarkers to indicate a neuroprotective/therapeutic response, remains elusive. Penetrating ballistic-like brain injury (PBBI) was used to systematically analyze several key TBI biomarkers, glial fibrillary acidic protein (GFAP) and its break-down products (BDPs)-ubiquitin C-terminal hydrolase-L1 (UCH-L1), α-II spectrin, and α-II spectrin BDPs (SBDPs)-in brain tissues and serum during an extended acute-subacute time-frame. In addition, neurological improvement and serum GFAP theranostic value was evaluated after neuroprotective treatment. In brain tissues, total GFAP increased more than three-fold 2 to 7 d after PBBI. However, this change was primarily due to GFAP-BDPs which increased to 2.7-4.8 arbitrary units (AU). Alpha-II spectrin was nearly ablated 3 d after PBBI, but somewhat recovered after 7 d. In conjunction with α-II spectrin loss, SBDP-145/150 increased approximately three-fold 2 to 7 d after PBBI (vs. sham, p<0.05). UCH-L1 protein levels were slightly decreased 7 d after PBBI but otherwise were unaffected. Serum GFAP was elevated by 3.2- to 8.8-fold at 2 to 4 h (vs. sham; p<0.05) and the 4 h increase was strongly correlated to 3 d GFAP-BDP abundance (r=0.66; p<0.05). Serum GFAP showed such a strong injury effect that it also was evaluated after therapeutic intervention with cyclosporin A (CsA). Administration of 2.5 mg/kg CsA significantly reduced serum GFAP elevation by 22.4-fold 2 h after PBBI (vs. PBBI+vehicle; p<0.05) and improved neurological function 1 d post-injury. Serum biomarkers, particularly GFAP, may be correlative tools of brain protein changes and feasible theranostic markers of TBI progression and recovery. PMID:25789543

  19. The Ministry of Industry and Information Technology Issued Detail Breakdown on the Tasks to Eliminate 2009 Backward Production Capacity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ In order to implement the spirit of "The Announcement from the State Council about Issuing the 2009 Work Plan on Energy-Saving and Emission-Reduction" and the adjustment and revitalization plan for key industries, and further improve the work to eliminate backward production capacity, the Ministry of Industry and Information Technology issued a notice on the detail breakdown and implementation of tasks to eliminate 2009 backward production capacity on November 25, 2009.

  20. Clastogenic Factors as Potential Biomarkers of Increased Superoxide Production

    Directory of Open Access Journals (Sweden)

    Ingrid Emerit

    2007-01-01

    Full Text Available The formation of clastogenic factors (CF and their damaging effects are mediated by superoxide, since superoxide dismutase is regularly protective. CF are produced via superoxide and stimulate the production of superoxide by monocytes and neutrophils. This results in a selfsustaining and longlasting process of clastogenesis, which may exceed the DNA repair system and ultimately lead to cancer (Emerit, 1994. An increased cancer risk is indeed observed in conditions accompanied by CF formation. These include irradiated persons, patients with chronic inflammatory diseases, HIV-infected persons and the chromosomal breakage syndromes ataxia telangiectasia, Bloom’s syndrome and Fanconi’s anemia. Biochemical analysis has identifi ed lipid peroxidation products, arachidonic acid metabolites, nucleotides of inosine and cytokines, in particular tumor necrosis factor alpha, as the clastogenic and also superoxide stimulating components of CF. Due to their chromosome damaging effects, these oxidants can be detected with classical cytogenetic techniques. Their synergistic action renders the CF-test particularly sensitive for the detection of a pro-oxidant state. Correlations were observed between CF and other biomarkers of oxidative stress such as decreases in total plasma thiols or increases in TBARS or chemiluminescence. Correlations between CF and disease activity, between CF and radiation exposure, suggest the study of CF for monitoring these conditions. CF may also be useful as biochemical markers and intermediate endpoints for the evaluation of promising antioxidant drugs. CF formation represents a link between chronic inflammation and carcinogenesis. Prophylactic use of superoxide scavengers as anticarcinogens is therefore suggested.

  1. A Framework of Combining Case-Based Reasoning with a Work Breakdown Structure for Estimating the Cost of Online Course Production Projects

    Science.gov (United States)

    He, Wu

    2014-01-01

    Currently, a work breakdown structure (WBS) approach is used as the most common cost estimation approach for online course production projects. To improve the practice of cost estimation, this paper proposes a novel framework to estimate the cost for online course production projects using a case-based reasoning (CBR) technique and a WBS. A…

  2. Phytoplankton Diversity and Geologically Relevant Carbon: Using metagenomics to determine phytoplankton biomarker production

    Science.gov (United States)

    Kodner, R. B.; Armbrust, E.

    2008-12-01

    Phytoplankton play an important role in the global carbon cycle, on short and long time scales. On long time scales, organic carbon, especially recalcitrant forms of biomass such as lipids, can be preserved and thus sequestered in sediments and rocks on geologic time scales. If the preserved lipids have some taxonomic specificity, they can be used as fossil biomarkers to characterize the community of organisms that contributed to ancient carbon sinks. Currently, it is not well understood how well the complex mixture of organic compounds preserved in geological carbon sinks represents the original community that produced those molecules or how the diversity of organism in a community is reflected in the lipid biomarkers they collectively synthesize. We have begun to investigate these questions by characterizing lipid biomarker production in modern phytoplankton communities with metagenomic data sets. Here we evaluate the information on community biomarker biosynthesis gathered from this type of data set using sterols as a case study. We have identified genes involved in sterol biosynthesis in a number of metagenomes and placed these genes in a phylogenetic context using a method designed to deal with short metagenomic sequences. The degree of taxonomic diversity of biomarker production measured with gene sequences can be more specific than lipid analysis alone.

  3. Optical spectroscopy of radiotherapy and photodynamic therapy responses in normal rat skin shows vascular breakdown products

    Science.gov (United States)

    Teles de Andrade, Cintia; Nogueira, Marcelo S.; Kanick, Stephen C.; Marra, Kayla; Gunn, Jason; Andreozzi, Jacqueline; Samkoe, Kimberley S.; Kurachi, Cristina; Pogue, Brian W.

    2016-03-01

    Photodynamic therapy (PDT) and radiotherapy are non-systemic cancer treatment options with different mechanisms of damage. So combining these techniques has been shown to have some synergy, and can mitigate their limitations such as low PDT light penetration or radiotherapy side effects. The present study monitored the induced tissue changes after PDT, radiotherapy, and a combination protocol in normal rat skin, using an optical spectroscopy system to track the observed biophysical changes. The Wistar rats were treated with one of the protocols: PDT followed by radiotherapy, PDT, radiotherapy and radiotherapy followed by PDT. Reflectance spectra were collected in order to observe the effects of these combined therapies, especially targeting vascular response. From the reflectance, information about oxygen saturation, met-hemoglobin and bilirubin concentration, blood volume fraction (BVF) and vessel radius were extracted from model fitting of the spectra. The rats were monitored for 24 hours after treatment. Results showed that there was no significant variation in the vessel size or BVF after the treatments. However, the PDT caused a significant increase in the met-hemoglobin and bilirubin concentrations, indicating an important blood breakdown. These results may provide an important clue on how the damage establishment takes place, helping to understand the effect of the combination of those techniques in order to verify the existence of a known synergistic effect.

  4. Biomarker Analysis of Stored Blood Products: Emphasis on Pre-Analytical Issues

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    Niels Lion

    2010-11-01

    Full Text Available Millions of blood products are transfused every year; many lives are thus directly concerned by transfusion. The three main labile blood products used in transfusion are erythrocyte concentrates, platelet concentrates and fresh frozen plasma. Each of these products has to be stored according to its particular components. However, during storage, modifications or degradation of those components may occur, and are known as storage lesions. Thus, biomarker discovery of in vivo blood aging as well as in vitro labile blood products storage lesions is of high interest for the transfusion medicine community. Pre-analytical issues are of major importance in analyzing the various blood products during storage conditions as well as according to various protocols that are currently used in blood banks for their preparations. This paper will review key elements that have to be taken into account in the context of proteomic-based biomarker discovery applied to blood banking.

  5. Biomarker analysis of stored blood products: emphasis on pre-analytical issues.

    Science.gov (United States)

    Delobel, Julien; Rubin, Olivier; Prudent, Michel; Crettaz, David; Tissot, Jean-Daniel; Lion, Niels

    2010-01-01

    Millions of blood products are transfused every year; many lives are thus directly concerned by transfusion. The three main labile blood products used in transfusion are erythrocyte concentrates, platelet concentrates and fresh frozen plasma. Each of these products has to be stored according to its particular components. However, during storage, modifications or degradation of those components may occur, and are known as storage lesions. Thus, biomarker discovery of in vivo blood aging as well as in vitro labile blood products storage lesions is of high interest for the transfusion medicine community. Pre-analytical issues are of major importance in analyzing the various blood products during storage conditions as well as according to various protocols that are currently used in blood banks for their preparations. This paper will review key elements that have to be taken into account in the context of proteomic-based biomarker discovery applied to blood banking. PMID:21151459

  6. Collagen breakdown products and lung collagen metabolism: an in vitro study on fibroblast cultures.

    OpenAIRE

    Gardi, C.; Calzoni, P.; Marcolongo, P.; E. Cavarra; Vanni, L.; G. Lungarella.

    1994-01-01

    BACKGROUND--In fibrotic diseases such as pulmonary fibrosis there is evidence suggesting enhanced synthesis and degradation of lung connective tissue components, including collagen. It has therefore been hypothesised that products of collagen degradation may have a role in the promotion of collagen deposition. In support of this hypothesis, it has recently been shown that intravenous injection of lung collagen degradation products in experimental animals stimulated collagen synthesis leading ...

  7. Biomarkers in natural fish populations indicate adverse biological effects of offshore oil production.

    Directory of Open Access Journals (Sweden)

    Lennart Balk

    Full Text Available BACKGROUND: Despite the growing awareness of the necessity of a sustainable development, the global economy continues to depend largely on the consumption of non-renewable energy resources. One such energy resource is fossil oil extracted from the seabed at offshore oil platforms. This type of oil production causes continuous environmental pollution from drilling waste, discharge of large amounts of produced water, and accidental spills. METHODS AND PRINCIPAL FINDINGS: Samples from natural populations of haddock (Melanogrammus aeglefinus and Atlantic cod (Gadus morhua in two North Sea areas with extensive oil production were investigated. Exposure to and uptake of polycyclic aromatic hydrocarbons (PAHs were demonstrated, and biomarker analyses revealed adverse biological effects, including induction of biotransformation enzymes, oxidative stress, altered fatty acid composition, and genotoxicity. Genotoxicity was reflected by a hepatic DNA adduct pattern typical for exposure to a mixture of PAHs. Control material was collected from a North Sea area without oil production and from remote Icelandic waters. The difference between the two control areas indicates significant background pollution in the North Sea. CONCLUSION: It is most remarkable to obtain biomarker responses in natural fish populations in the open sea that are similar to the biomarker responses in fish from highly polluted areas close to a point source. Risk assessment of various threats to the marine fish populations in the North Sea, such as overfishing, global warming, and eutrophication, should also take into account the ecologically relevant impact of offshore oil production.

  8. Receptors responsive to protein breakdown products in G-cells and D-cells of mouse, swine and human

    Directory of Open Access Journals (Sweden)

    Désirée Christine Haid

    2012-04-01

    Full Text Available Monitoring the luminal content in the stomach is of vital importance for adjusting the gastric activities, including the release of gastric hormones such as gastrin. Our previous studies have shown that in mice the gastrin-secreting G-cells express receptor types which are responsive to amino acids. Since the pig is considered as more suitable model for studying gastro-physiological aspects relevant for men, in this study we have analysed the distribution of G-cells and D-cells in the gastric antrum of men, swine and mouse and the expression of receptor types which may render these cells responsiveness to protein breakdown products. The results indicate that the number of G-cells per antral invagination was significantly higher in swine and human compared to mice and also the distribution pattern for G-cells differed between the species. The molecular phenotyping revealed that the receptors GPRC6A and CaSR were also expressed in G- and D-cells from swine and men. In the course of this study, an additional receptor type was found to be expressed in G- and D-cells, the peptone-receptor GPR92. This receptor type may be particular suitable for sensing protein breakdown products and thus be a key element to adjust the activity of G-cells and D-cells according to the progress of the digestive processes in the stomach. In search for elements of an intracellular signaling cascade it was found that G-cells express the G-protein subunits Gαq and Gαi2, as well as the phospholipase C subtype PLCβ3. In contrast, D-cells expressed the subtype PLCβ2 and neither Gαq nor Gαi2. These results indicate that there are significant species differences concerning the number and distribution pattern of gastric endocrine cells. However, the molecular phenotype of G-cells and D-cells appears to be similar in the three species.

  9. Soluble Receptor for Advanced Glycation End Product: A Biomarker for Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Louise J. N. Jensen

    2015-01-01

    Full Text Available The receptor of advanced glycation end products (RAGE and its ligands are linked to the pathogenesis of coronary artery disease (CAD, and circulating soluble receptor of advanced glycation end products (sRAGE, reflecting the RAGE activity, is suggested as a potential biomarker. Elevated sRAGE levels are reported in relation to acute ischemia and this review focuses on the role of sRAGE as a biomarker for the acute coronary syndrome (ACS. The current studies demonstrated that sRAGE levels are elevated in relation to ACS, however during a very narrow time period, indicating that the time of sampling needs attention. Interestingly, activation of RAGE may influence the pathogenesis and reflection in sRAGE levels in acute and stable CAD differently.

  10. Laser induced breakdown spectroscopy surface analysis correlated with the process of nanoparticle production by laser ablation in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Apostol, I., E-mail: ileana.apostol@inflpr.ro; Damian, V. [National Institute for Laser, Plasma and Radiation Physics (Romania); Damian, R.; Nistor, L. C. [National Institute for Materials Physics (Romania); Pascu, A.; Staicu, A.; Udrea, C. [National Institute for Laser, Plasma and Radiation Physics (Romania)

    2013-04-15

    Laser induced ablation of solids situated in liquids (LAL) was used in order to produce nanoparticles. Laser induced breakdown spectroscopy (LIBS) surface analysis correlated with the process of nanoparticle production by LAL was applied to explain the composition of the obtained nanoparticles as determined by Electron Dispersive X-ray Spectroscopy (EDS). In the case of aluminum rods placed in distilled water irradiated with pulsed laser radiation (355 nm wavelength, 6 ns pulse length) we have obtained spheric nanoparticles with dimensions lower than 100 nm. Quantitative EDS analyses on the obtained spheres showed the presence of, Al, O, and Si. This indicates that probably the composition of the nanoparticles is an aluminum silicate. LIBS analysis on the aluminum target have shown the presence of a Si line with low intensity indicating a small quantity of silicon in the first ablated layers. The LIBS spectra for a sequence of pulses evidenced also that the intensity of the aluminum lines after a number of pulses decreases. This means that the quantity of ablated material becomes smaller due to the ablation depth decrease.

  11. Electrolysis within anaerobic bioreactors stimulates breakdown of toxic products from azo dye treatment.

    Science.gov (United States)

    Gavazza, Sávia; Guzman, Juan J L; Angenent, Largus T

    2015-04-01

    Azo dyes are the most widely used coloring agents in the textile industry, but are difficult to treat. When textile effluents are discharged into waterways, azo dyes and their degradation products are known to be environmentally toxic. An electrochemical system consisting of a graphite-plate anode and a stainless-steel mesh cathode was placed into a lab-scale anaerobic bioreactor to evaluate the removal of an azo dye (Direct Black 22) from synthetic textile wastewater. At applied potentials of 2.5 and 3.0 V when water electrolysis occurs, no improvement in azo dye removal efficiency was observed compared to the control reactor (an integrated system with electrodes but without an applied potential). However, applying such electric potentials produces oxygen via electrolysis and promoted the aerobic degradation of aromatic amines, which are toxic, intermediate products of anaerobic azo dye degradation. The removal of these amines indicates a decrease in overall toxicity of the effluent from a single-stage anaerobic bioreactor, which warrants further optimization in anaerobic digestion.

  12. Efficient breakdown of lignocellulose using mixed-microbe populations for bioethanol production.

    Energy Technology Data Exchange (ETDEWEB)

    Murton, Jaclyn K.; Ricken, James Bryce; Powell, Amy Jo

    2009-11-01

    This report documents progress in discovering new catalytic technologies that will support the development of advanced biofuels. The global shift from petroleum-based fuels to advanced biofuels will require transformational breakthroughs in biomass deconstruction technologies, because current methods are neither cost effective nor sufficiently efficient or robust for scaleable production. Discovery and characterization of lignocellulolytic enzyme systems adapted to extreme environments will accelerate progress. Obvious extreme environments to mine for novel lignocellulolytic deconstruction technologies include aridland ecosystems (ALEs), such as those of the Sevilleta Long Term Ecological Research (LTER) site in central New Mexico (NM). ALEs represent at least 40% of the terrestrial biosphere and are classic extreme environments, with low nutrient availability, high ultraviolet radiation flux, limited and erratic precipitation, and extreme variation in temperatures. ALEs are functionally distinct from temperate environments in many respects; one salient distinction is that ALEs do not accumulate soil organic carbon (SOC), in marked contrast to temperate settings, which typically have large pools of SOC. Low productivity ALEs do not accumulate carbon (C) primarily because of extraordinarily efficient extracellular enzyme activities (EEAs) that are derived from underlying communities of diverse, largely uncharacterized microbes. Such efficient enzyme activities presumably reflect adaptation to this low productivity ecosystem, with the result that all available organic nutrients are assimilated rapidly. These communities are dominated by ascomycetous fungi, both in terms of abundance and contribution to ecosystem-scale metabolic processes, such as nitrogen and C cycling. To deliver novel, robust, efficient lignocellulolytic enzyme systems that will drive transformational advances in biomass deconstruction, we have: (1) secured an award through the Department of Energy

  13. Analyzing randomly occurring voltage breakdowns

    International Nuclear Information System (INIS)

    During acceptance testing of high-vacuum neutron tubes, 40% of the tubes failed after experiencing high-voltage breakdowns during the aging process. Use of a digitizer in place of an oscilloscope revealed two types of breakdowns, only one of which affected acceptance testing. This information allowed redesign of the aging sequence to prevent tube damage and improve yield and quality of the final product

  14. Lung cancer biomarkers for the assessment of modified risk tobacco products: an oxidative stress perspective.

    Science.gov (United States)

    Lowe, Frazer J; Luettich, Karsta; Gregg, Evan O

    2013-05-01

    Manufacturers have developed prototype cigarettes yielding reduced levels of some tobacco smoke toxicants, when tested using laboratory machine smoking under standardised conditions. For the scientific assessment of modified risk tobacco products, tests that offer objective, reproducible data, which can be obtained in a much shorter time than the requirements of conventional epidemiology are needed. In this review, we consider whether biomarkers of biological effect related to oxidative stress can be used in this role. Based on published data, urinary 8-oxo-7,8-dihydro-2-deoxyguanosine, thymidine glycol, F2-isoprostanes, serum dehydroascorbic acid to ascorbic acid ratio and carotenoid concentrations show promise, while 4-hydroxynonenal requires further qualification.

  15. RF breakdown by toroidal helicons

    Indian Academy of Sciences (India)

    S K P Tripathi; D Bora; M Mishra

    2001-04-01

    Bounded whistlers are well-known for their efficient plasma production capabilities in thin cylindrical tubes. In this paper we shall present their radio frequency (RF) breakdown and discharge sustaining capabilities in toroidal systems. Pulsed RF power in the electronmagnetohydrodynamic (EMHD) frequency regime is fed to the neutral background medium. After the breakdown stage, discharge is sustained by toroidal bounded whistlers. In these pulsed experiments the behaviour of the time evolution of the discharge could be studied in four distinct phases of RF breakdown, steady state attainment, decay and afterglow. In the steady state average electron density of ≈ 1012 per cc and average electron temperature of ≈ 20 eV are obtained at 10-3 mbar of argon filling pressure. Experimental results on toroidal mode structure, background effects and time evolution of the electron distribution function will be presented and their implications in understanding the breakdown mechanism are discussed.

  16. Identification of biomarkers for intake of protein from meat, dairy products and grains : a controlled dietary intervention study

    NARCIS (Netherlands)

    Altorf-van der Kuil, Wieke; Brink, Elizabeth J.; Boetje, Martine; Siebelink, Els; Bijlsma, Sabina; Engberink, Marielle F.; van 't Veer, Pieter; Tome, Daniel; Bakker, Stephan J. L.; van Baak, Marleen A.; Geleijnse, Johanna M.

    2013-01-01

    In the present controlled, randomised, multiple cross-over dietary intervention study, we aimed to identify potential biomarkers for dietary protein from dairy products, meat and grain, which could be useful to estimate intake of these protein types in epidemiological studies. After 9 d run-in, thir

  17. Identification of biomarkers for intake of protein from meat, dairy products and grains: A controlled dietary intervention study

    NARCIS (Netherlands)

    Altorf-van der Kuil, W.; Brink, E.J.; Boetje, M.; Siebelink, E.; Bijlsma, S.; Engberink, M.F.; Veer, P.V.'.; Tomé, D.; Bakker, S.J.L.; Baak, M.A. van; Geleijnse, J.M.

    2013-01-01

    In the present controlled, randomised, multiple cross-over dietary intervention study, we aimed to identify potential biomarkers for dietary protein from dairy products, meat and grain, which could be useful to estimate intake of these protein types in epidemiological studies. After 9 d run-in, thir

  18. Identification of biomarkers for intake of protein from meat, dairy products and grains: a controlled dietary intervention study

    NARCIS (Netherlands)

    Altorf-van der Kuil, W.; Brink, E.J.; Boetje, M.; Siebelink, E.; Bijlsma, S.; Engberink, M.F.; Tome, D.; Bakker, S.J.; Baak, van M.A.; Geleijnse, J.M.; Veer, van 't P.

    2013-01-01

    In the present controlled, randomised, multiple cross-over dietary intervention study, we aimed to identify potential biomarkers for dietary protein from dairy products, meat and grain, which could be useful to estimate intake of these protein types in epidemiological studies. After 9 d run-in, thir

  19. Cholesterol oxidation products are sensitive and specific blood-based biomarkers for Niemann-Pick C1 disease

    OpenAIRE

    Porter, Forbes D.; Scherrer, David E.; Lanier, Michael H.; Langmade, S. Joshua; Molugu, Vasumathi; Gale, Sarah E.; Olzeski, Dana; Sidhu, Rohini; Dietzen, Dennis J.; Fu, Rao; Wassif, Christopher A.; Yanjanin, Nicole M.; Marso, Steven P.; House, John; Vite, Charles

    2010-01-01

    Niemann-Pick type C1 (NPC1) disease is a rare progressive neurodegenerative disorder characterized by endolysosomal cholesterol accumulation. Previous studies implicating oxidative stress in NPC1 disease pathogenesis raised the possibility that non-enzymatic formation of cholesterol oxidation products could serve as disease biomarkers. We measured these metabolites in the plasma and tissues of the Npc1−/− mouse model and found several cholesterol oxidation products that were elevated in Npc1−...

  20. Research on Performance Evaluation of Complex Product Project Work Breakdown%复杂产品项目工作分解绩效评价的研究

    Institute of Scientific and Technical Information of China (English)

    任南; 潘微微; 何彦昕

    2015-01-01

    构建复杂产品项目工作分解绩效的评价体系,对多家大型复杂产品制造企业实施问卷调查,在定性提出假设的基础上,运用结构方程模型(SEM)定量分析并验证假设。结果表明:核心能力与研发(R&D)能力能够增强产出能力,且研发能力是产出能力最重要和最直接的影响要素;管理能力、基础能力和投入能力是项目管理不可或缺的能力要素。在此基础上,对如何提高复杂产品项目工作分解绩效提出了相关建议。%In order to construct a performance evaluation system of complex product work breakdown,the paper chooses a number of large complex manufacturing enterprises as research object and distributes questionnaires to them.Then,we use qualitative research and structural equation modeling (SEM)to give quantitative data and analyze the hypothesis.Research shows that enterprises should enhance output capacity through core competency and R &D capability.What's more,R &D capability is the most important and direct factor ability to output capacity.Meanwhile,management capability,input ca-pacity and basic capacity are essential as well.Based on the theoretical analysis,we provide some suggestions about how to promote the performance of complex product project work breakdown.

  1. Combined free nitrous acid and hydrogen peroxide pre-treatment of waste activated sludge enhances methane production via organic molecule breakdown

    Science.gov (United States)

    Zhang, Tingting; Wang, Qilin; Ye, Liu; Batstone, Damien; Yuan, Zhiguo

    2015-11-01

    This study presents a novel pre-treatment strategy using combined free nitrous acid (FNA i.e. HNO2) and hydrogen peroxide (H2O2) to enhance methane production from WAS, with the mechanisms investigated bio-molecularly. WAS from a full-scale plant was treated with FNA alone (1.54 mg N/L), H2O2 alone (10-80 mg/g TS), and their combinations followed by biochemical methane potential tests. Combined FNA and H2O2 pre-treatment substantially enhanced methane potential of WAS by 59-83%, compared to 13-23% and 56% with H2O2 pre-treatment alone and FNA pre-treatment alone respectively. Model-based analysis indicated the increased methane potential was mainly associated with up to 163% increase in rapidly biodegradable fraction with combined pre-treatment. The molecular weight distribution and chemical structure analyses revealed the breakdown of soluble macromolecules with the combined pre-treatment caused by the deamination and oxidation of the typical functional groups in proteins, polysaccharides and phosphodiesters. These changes likely improved the biodegradability of WAS.

  2. Production and early preservation of lipid biomarkers in iron hot springs.

    Science.gov (United States)

    Parenteau, Mary N; Jahnke, Linda L; Farmer, Jack D; Cady, Sherry L

    2014-06-01

    The bicarbonate-buffered anoxic vent waters at Chocolate Pots hot springs in Yellowstone National Park are 51-54°C, pH 5.5-6.0, and are very high in dissolved Fe(II) at 5.8-5.9 mg/L. The aqueous Fe(II) is oxidized by a combination of biotic and abiotic mechanisms and precipitated as primary siliceous nanophase iron oxyhydroxides (ferrihydrite). Four distinct prokaryotic photosynthetic microbial mat types grow on top of these iron deposits. Lipids were used to characterize the community composition of the microbial mats, link source organisms to geologically significant biomarkers, and investigate how iron mineralization degrades the lipid signature of the community. The phospholipid and glycolipid fatty acid profiles of the highest-temperature mats indicate that they are dominated by cyanobacteria and green nonsulfur filamentous anoxygenic phototrophs (FAPs). Diagnostic lipid biomarkers of the cyanobacteria include midchain branched mono- and dimethylalkanes and, most notably, 2-methylbacteriohopanepolyol. Diagnostic lipid biomarkers of the FAPs (Chloroflexus and Roseiflexus spp.) include wax esters and a long-chain tri-unsaturated alkene. Surprisingly, the lipid biomarkers resisted the earliest stages of microbial degradation and diagenesis to survive in the iron oxides beneath the mats. Understanding the potential of particular sedimentary environments to capture and preserve fossil biosignatures is of vital importance in the selection of the best landing sites for future astrobiological missions to Mars. This study explores the nature of organic degradation processes in moderately thermal Fe(II)-rich groundwater springs--environmental conditions that have been previously identified as highly relevant for Mars exploration.

  3. Production and Early Preservation of Lipid Biomarkers in Iron Hot Springs

    Energy Technology Data Exchange (ETDEWEB)

    Parenteau, Mary N.; Jahnke, Linda L.; Farmer, Jack D.; Cady, Sherry L.

    2014-06-01

    The bicarbonate-buffered anoxic vent waters at Chocolate Pots hot springs in Yellowstone National Park are 51–54°C, pH 5.5–6.0, and are very high in dissolved Fe(II) at 5.8–5.9 mg/L. The aqueous Fe(II) is oxidized by a combination of biotic and abiotic mechanisms and precipitated as primary siliceous nanophase iron oxyhydroxides (ferrihydrite). Four distinct prokaryotic photosynthetic microbial mat types grow on top of these iron deposits. Lipids were used to characterize the community composition of the microbial mats, link source organisms to geologically significant biomarkers, and investigate how iron mineralization degrades the lipid signature of the community. The phospholipid and glycolipid fatty acid profiles of the highest-temperature mats indicate that they are dominated by cyanobacteria and green nonsulfur filamentous anoxygenic phototrophs (FAPs). Diagnostic lipid biomarkers of the cyanobacteria include midchain branched mono- and dimethylalkanes and, most notably, 2-methylbacteriohopanepolyol. Diagnostic lipid biomarkers of the FAPs (Chloroflexus and Roseiflexus spp.) include wax esters and a long-chain tri-unsaturated alkene. Surprisingly, the lipid biomarkers resisted the earliest stages of microbial degradation and diagenesis to survive in the iron oxides beneath the mats. Understanding the potential of particular sedimentary environments to capture and preserve fossil biosignatures is of vital importance in the selection of the best landing sites for future astrobiological missions to Mars. Finally, this study explores the nature of organic degradation processes in moderately thermal Fe(II)-rich groundwater springs—environmental conditions that have been previously identified as highly relevant for Mars exploration.

  4. Comparison of the serum fibrin-fibrinogen degradation products with cytokeratin 19 fragment as biomarkers in patients with lung cancer.

    Science.gov (United States)

    So, Hee Jin; Hong, Seok-Il; Lee, Jin Kyung; Chang, Yoon Hwan; Kang, Sun Jung; Hong, Young Jun

    2014-09-01

    Lung cancer is one of the main causes of cancer-related mortality. The identification of early diagnostic biomarkers improved outcomes for lung cancer patients. Serum fibrin-fibrinogen degradation products (FDP) levels are elevated in numerous malignancies due to hemostatic alterations. The serum FDP levels were compared to the levels of cytokeratin 19 fragment antigen (CYFRA 21-1), another well-established biomarker. The serum samples from 193 lung cancer patients, 84 healthy controls and 106 patients with benign respiratory diseases were obtained. The serum FDP level was measured using the DR-70 immunoassay and the CYFRA 21-1 level was measured by electrochemiluminescence using the Roche Analytics E170. Receiver operating characteristics curves were used to assess the predictive sensitivity and specificity. The mean serum FDP level in lung cancer patients (35.01±229.02 μg/ml) was significantly higher compared to the 190 non-cancerous subjects (0.60±0.75 μg/ml; P=0.039). The mean serum CYFRA 21-1 level in lung cancer patients (4.50±6.67 ng/ml) was also significantly higher compared to the non-cancerous subjects (1.40±0.83 ng/ml; PCYFRA 21-1 exhibited clinical sensitivity and specificity of 77 and 74%, respectively, at a cut-off of 1.65 ng/ml. The serum FDP area under the curve (0.87) was slightly higher compared to CYFRA 21-1 (0.83). Therefore, it is apparent that serum FDP is comparable to CYFRA 21-1 as a lung cancer biomarker and can be used for clinical practice. PMID:25054020

  5. Beauty in the Breakdown

    Science.gov (United States)

    Brisco, Nicole

    2008-01-01

    Most human beings look at erosion as the destruction of a surface, but artists can see that erosion often creates indefinable beauty. Where do you see beauty in the breakdown? In this article, the author presents an innovative lesson that would allow students to observe both human and physical nature. In this activity students will create a work…

  6. Cave breakdown by vadose weathering.

    OpenAIRE

    Osborne R. Armstrong L.

    2002-01-01

    Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coate...

  7. Increased levels of urinary biomarkers of lipid peroxidation products among workers occupationally exposed to diesel engine exhaust.

    Science.gov (United States)

    Bin, Ping; Shen, Meili; Li, Haibin; Sun, Xin; Niu, Yong; Meng, Tao; Yu, Tao; Zhang, Xiao; Dai, Yufei; Gao, Weimin; Gu, Guizhen; Yu, Shanfa; Zheng, Yuxin

    2016-08-01

    Diesel engine exhaust (DEE) was found to induce lipid peroxidation (LPO) in animal exposure studies. LPO is a class of oxidative stress and can be reflected by detecting the levels of its production, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and etheno-DNA adducts including 1,N(6)-etheno-2'-deoxyadenosine (ɛdA) and 3,N(4)-etheno-2'-deoxycytidine (ɛdC). However, the impact of DEE exposure on LPO has not been explored in humans. In this study, we evaluated urinary MDA, 4-HNE, ɛdA, and ɛdC levels as biomarkers of LPO among 108 workers with exclusive exposure to DEE and 109 non-DEE-exposed workers. Results showed that increased levels of urinary MDA and ɛdA were observed in subjects occupationally exposed to DEE before and after age, body mass index (BMI), smoking status, and alcohol use were adjusted (all p < 0.001). There was a statistically significant relationship between the internal exposure dose (urinary ΣOH-PAHs) and MDA, 4-HNE, and ɛdA (all p < 0.001). Furthermore, significant increased relations between urinary etheno-DNA adduct and MDA, 4-HNE were observed (all p < 0.05). The findings of this study suggested that the level of LPO products (MDA and ɛdA) was increased in DEE-exposed workers, and urinary MDA and ɛdA might be feasible biomarkers for DEE exposure. LPO induced DNA damage might be involved and further motivated the genomic instability could be one of the pathogeneses of cancer induced by DEE-exposure. However, additional investigations should be performed to understand these observations. PMID:27087348

  8. Space Charge Modulated Electrical Breakdown

    Science.gov (United States)

    Li, Shengtao; Zhu, Yuanwei; Min, Daomin; Chen, George

    2016-09-01

    Electrical breakdown is one of the most important physical phenomena in electrical and electronic engineering. Since the early 20th century, many theories and models of electrical breakdown have been proposed, but the origin of one key issue, that the explanation for dc breakdown strength being twice or higher than ac breakdown strength in insulating materials, remains unclear. Here, by employing a bipolar charge transport model, we investigate the space charge dynamics in both dc and ac breakdown processes. We demonstrate the differences in charge accumulations under both dc and ac stresses and estimate the breakdown strength, which is modulated by the electric field distortion induced by space charge. It is concluded that dc breakdown initializes in the bulk whereas ac breakdown initializes in the vicinity of the sample-electrode interface. Compared with dc breakdown, the lower breakdown strength under ac stress and the decreasing breakdown strength with an increase in applied frequency, are both attributed to the electric field distortion induced by space charges located in the vicinity of the electrodes.

  9. Space Charge Modulated Electrical Breakdown.

    Science.gov (United States)

    Li, Shengtao; Zhu, Yuanwei; Min, Daomin; Chen, George

    2016-01-01

    Electrical breakdown is one of the most important physical phenomena in electrical and electronic engineering. Since the early 20(th) century, many theories and models of electrical breakdown have been proposed, but the origin of one key issue, that the explanation for dc breakdown strength being twice or higher than ac breakdown strength in insulating materials, remains unclear. Here, by employing a bipolar charge transport model, we investigate the space charge dynamics in both dc and ac breakdown processes. We demonstrate the differences in charge accumulations under both dc and ac stresses and estimate the breakdown strength, which is modulated by the electric field distortion induced by space charge. It is concluded that dc breakdown initializes in the bulk whereas ac breakdown initializes in the vicinity of the sample-electrode interface. Compared with dc breakdown, the lower breakdown strength under ac stress and the decreasing breakdown strength with an increase in applied frequency, are both attributed to the electric field distortion induced by space charges located in the vicinity of the electrodes. PMID:27599577

  10. Work Breakdown Structure (WBS) Handbook

    Science.gov (United States)

    2010-01-01

    The purpose of this document is to provide program/project teams necessary instruction and guidance in the best practices for Work Breakdown Structure (WBS) and WBS dictionary development and use for project implementation and management control. This handbook can be used for all types of NASA projects and work activities including research, development, construction, test and evaluation, and operations. The products of these work efforts may be hardware, software, data, or service elements (alone or in combination). The aim of this document is to assist project teams in the development of effective work breakdown structures that provide a framework of common reference for all project elements. The WBS and WBS dictionary are effective management processes for planning, organizing, and administering NASA programs and projects. The guidance contained in this document is applicable to both in-house, NASA-led effort and contracted effort. It assists management teams from both entities in fulfilling necessary responsibilities for successful accomplishment of project cost, schedule, and technical goals. Benefits resulting from the use of an effective WBS include, but are not limited to: providing a basis for assigned project responsibilities, providing a basis for project schedule development, simplifying a project by dividing the total work scope into manageable units, and providing a common reference for all project communication.

  11. Biomarkers for immune thrombocytopenia

    OpenAIRE

    Yu, Lingjia; Zhang, Chunmei; Zhang, Liping; Shi, Yongyu; Ji, Xuebin

    2015-01-01

    Immune thrombocytopenia is an autoimmune disease with abnormal biomarkers. Immune thrombocytopenia pathogenesis is a complicated process in which the patient’s immune system is activated by platelet autoantigens resulting in immune mediated platelet destruction or suppression of platelet production. The autoantibodies produced by autoreactive B cells against self antigens are considered to play a crucial role. In addition, biomarkers such as transforming growth factor-beta1,Toll-like receptor...

  12. Biomarker Identification in Metabolomics of Dietary Studies on Apple and Apple Products

    DEFF Research Database (Denmark)

    Rago, Daniela

    Nutrients and bioactive components present in fruits and vegetables interact with several metabolic pathways and physiological functions leading to a potential reduce of the risk of diseases. Metabolomics is a methodology that allows the measurements hundreds of compounds in biological samples...... of the other periods) in order to select the important features discriminating the difference between control and apple or apple products supplementations. Whole apples and pomace were characterized by having the strongest effect to decrease the levels of branched-chain amino acid and their gut microbial...... fermentation products as well as short and medium chain acylcarnitine. Furthermore, lower levels of primary and secondary bile acids and some lysophospholipids were observed with apple and apple product supplementations, while levels of uric acid increased. In PAPER III, 24 h urine metabolic profilings from...

  13. Breakdowns in collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2010-01-01

    Collaborative information seeking is integral to many professional activities. In hospital work, the medication process encompasses continual seeking for information and collaborative grounding of information. This study investigates breakdowns in collaborative information seeking through analyses...... of the use of the electronic medication record adopted in a Danish healthcare region and of the reports of five years of medication incidents at Danish hospitals. The results show that breakdowns in collaborative information seeking is a major source of medication incidents, that most of these breakdowns...

  14. Earthworm cast production as a new behavioural biomarker for toxicity testing.

    OpenAIRE

    Capowiez, Yvan; Dittbrenner, Nils; Rault-Léonardon, Magali; Triebskorn, Rita; Hedde, Mickaël; Mazzia, Christophe

    2010-01-01

    There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP was found to be linearly correlated to earthworm biomass and to be greatly influenced by soil water content. Azinphos-methyl had no effect on CP a...

  15. On Preliminary Breakdown

    Science.gov (United States)

    Beasley, W. H.; Petersen, D.

    2013-12-01

    The preliminary breakdown phase of a negative cloud-to-ground lightning flash was observed in detail. Observations were made with a Photron SA1.1 high-speed video camera operating at 9,000 frames per second, fast optical sensors, a flat-plate electric field antenna covering the SLF to MF band, and VHF and UHF radio receivers with bandwidths of 20 MHz. Bright stepwise extensions of a negative leader were observed at an altitude of 8 km during the first few milliseconds of the flash, and were coincident with bipolar electric field pulses called 'characteristic pulses'. The 2-D step lengths of the preliminary processes were in excess of 100 meters, with some 2-D step lengths in excess of 200 meters. Smaller and shorter unipolar electric field pulses were superposed onto the bipolar electric field pulses, and were coincident with VHF and UHF radio pulses. After a few milliseconds, the emerging negative stepped leader system showed a marked decrease in luminosity, step length, and propagation velocity. Details of these events will be discussed, including the possibility that the preliminary breakdown phase consists not of a single developing lightning leader system, but of multiple smaller lightning leader systems that eventually join together into a single system.

  16. Earthworm cast production as a new behavioural biomarker for toxicity testing

    Energy Technology Data Exchange (ETDEWEB)

    Capowiez, Yvan, E-mail: capowiez@avignon.inra.f [INRA, UR1115 ' Plantes et Systemes Horticoles' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Dittbrenner, Nils [INRA, UR1115 ' Plantes et Systemes Horticoles' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Rault, Magali [UAPV, UMR406 ' Abeilles et Environnement' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France); Triebskorn, Rita [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Hedde, Mickael [INRA, UR251 ' PESSAC' , RD10, 78026 Versailles Cedex (France); Mazzia, Christophe [UAPV, UMR406 ' Abeilles et Environnement' , Domaine Saint Paul, 84914 Avignon Cedex 09 (France)

    2010-02-15

    There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP was found to be linearly correlated to earthworm biomass and to be greatly influenced by soil water content. Azinphos-methyl had no effect on CP at all the concentrations tested. Significant decreases were observed at the normal application rate for other pesticides with (imidacloprid, carbaryl, methomyl) or without (ethyl-parathion and chlorpyrifos-ethyl) a clear concentration-effect response. For the highest concentration tested, reduction in CP varied between 35 and 67%. CP is straightforward and rapidly measured and ecologically meaningful. We thus believe it to be of great use as an endpoint in ecotoxicity testing. - Cast production of Lumbricus terrestris is affected by pesticides under laboratory conditions.

  17. Evolution of M. bovis BCG Vaccine: Is Niacin Production Still a Valid Biomarker?

    Directory of Open Access Journals (Sweden)

    Sarman Singh

    2015-01-01

    Full Text Available BCG vaccine is usually considered to be safe though rarely serious complications have also been reported, often incriminating contamination of the seed strain with pathogenic Mycobacterium tuberculosis. In such circumstances, it becomes prudent to rule out the contamination of the vaccine seed. M. bovis BCG can be confirmed by the absence of nitrate reductase, negative niacin test, and resistance to pyrazinamide and cycloserine. Recently in India, some stocks were found to be niacin positive which led to a national controversy and closer of a vaccine production plant. This prompted us to write this review and the comparative biochemical and genotypic studies were carried out on the these contentious vaccine stocks at the Indian vaccine plant and other seeds and it was found that some BCG vaccine strains and even some strains of M. bovis with eugenic-growth characteristics mainly old laboratory strains may give a positive niacin reaction. Most probably, the repeated subcultures lead to undefined changes at the genetic level in these seed strains. These changing biological characteristics envisage reevaluation of biochemical characters of existing BCG vaccine seeds and framing of newer guidelines for manufacturing, production, safety, and effectiveness of BCG vaccine.

  18. Evolution of M. bovis BCG Vaccine: Is Niacin Production Still a Valid Biomarker?

    Science.gov (United States)

    Singh, Sarman; Kumar, Manoj; Singh, Pragati

    2015-01-01

    BCG vaccine is usually considered to be safe though rarely serious complications have also been reported, often incriminating contamination of the seed strain with pathogenic Mycobacterium tuberculosis. In such circumstances, it becomes prudent to rule out the contamination of the vaccine seed. M. bovis BCG can be confirmed by the absence of nitrate reductase, negative niacin test, and resistance to pyrazinamide and cycloserine. Recently in India, some stocks were found to be niacin positive which led to a national controversy and closer of a vaccine production plant. This prompted us to write this review and the comparative biochemical and genotypic studies were carried out on the these contentious vaccine stocks at the Indian vaccine plant and other seeds and it was found that some BCG vaccine strains and even some strains of M. bovis with eugenic-growth characteristics mainly old laboratory strains may give a positive niacin reaction. Most probably, the repeated subcultures lead to undefined changes at the genetic level in these seed strains. These changing biological characteristics envisage reevaluation of biochemical characters of existing BCG vaccine seeds and framing of newer guidelines for manufacturing, production, safety, and effectiveness of BCG vaccine. PMID:25694828

  19. Impact effect of lycopene and tomato-based products network on cardioprotective biomarkers in vivo

    Directory of Open Access Journals (Sweden)

    Nermin N. El-Nashar

    2012-05-01

    Full Text Available Background: Dietary intake plays an important role as nutritional supplements are known to provide potential health benefits in cardiovascular disease. Recent studies suggest that the dietary intake of tomatoes and tomato products containing lycopene are associated with a decreased risk of cardiovascular disease. In order to substantiate these facts, the present study was undertaken to investigate the effectiveness of lycopene from tomato products on the potential effects of oxidative stress and atherosclerosis in vivo, focusing on early atherosclerotic events.Methods: Thirty male albino rats were assigned randomly into 5 groups; group C was the negative control group fed a basal diet, group H was the positive control fed a high-fat diet(HFD, group TS (HFD was fed a 8% lyophilized tomato paste, group TW (HFD was fed a24% lyophilized raw tomato, and group L (HFD was fed 0.1% mg pure lycopene. The level of serum; total cholesterol (TC, total triglyceride (TG, high-density lipoprotein cholesterol (HDLc, and low-density lipoprotein cholesterol (LDL-c was measured after 8 weeks of experimental treatment. Malondialdehyde (MDH plasma levels were measured in heart tissue homogenate. Furthermore, pathologic changes of the heart and aorta were also assessed.Results: We found that TC, TG, LDL-c and MDH, levels were significantly increased in group H (P < 0.05 compared to the negative control group. Administration of TS, TW and L demonstrated significant changes in these parameters (P < 0.05. The TW group (fed 24% oflyophilized raw tomato components had more positive effects than the TS & L groups. Furthermore, morphologic changes of heart and aorta revealed that TW and TS had a similar preventive effect against the development of atherosclerosis.Functional Foods in Health and Disease 2012, 2(5:151-165Conclusion: Our study indicated that raw tomatoes have a higher potential effect when compared to tomato paste or lycopene alone. This potential effect

  20. Biomarkers for neuromyelitis optica.

    Science.gov (United States)

    Chang, Kuo-Hsuan; Ro, Long-Sun; Lyu, Rong-Kuo; Chen, Chiung-Mei

    2015-02-01

    Neuromyelitis optica (NMO) is an acquired, heterogeneous inflammatory disorder, which is characterized by recurrent optic neuritis and longitudinally extensive spinal cord lesions. The discovery of the serum autoantibody marker, anti-aquaporin 4 (anti-AQP4) antibody, revolutionizes our understanding of pathogenesis of NMO. In addition to anti-AQP4 antibody, other biomarkers for NMO are also reported. These candidate biomarkers are particularly involved in T helper (Th)17 and astrocytic damages, which play a critical role in the development of NMO lesions. Among them, IL-6 in the peripheral blood is associated with anti-AQP4 antibody production. Glial fibrillary acidic protein (GFAP) in CSF demonstrates good correlations with clinical severity of NMO relapses. Detecting these useful biomarkers may be useful in the diagnosis and evaluation of disease activity of NMO. Development of compounds targeting these biomarkers may provide novel therapeutic strategies for NMO. This article will review the related biomarker studies in NMO and discuss the potential therapeutics targeting these biomarkers.

  1. Cave breakdown by vadose weathering.

    Directory of Open Access Journals (Sweden)

    Osborne R. Armstrong L.

    2002-01-01

    Full Text Available Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coated, rather than having fresh broken faces, and blocks continue to disintegrate after separating from the bedrock. Not only gypsum, but also hydromagnesite and aragonite are responsible for crystal wedging. It is impossible to study or identify potential breakdown foci by surface surveys alone, in-cave observation and mapping are essential.

  2. The added value of biomarker analysis to the genesis of plaggic Anthrosols; the identification of stable fillings used for the production of plaggic manure

    Science.gov (United States)

    van Mourik, Jan M.; Wagner, Thomas V.; Geert de Boer, J.; Jansen, Boris

    2016-07-01

    Plaggic Anthrosols are the result of historical forms of land management in cultural landscapes on chemically poor sandy substrates. Application of plaggic manure was responsible for the development of the plaggic horizons of these agricultural soils. Pollen diagrams reflect aspects of the environmental development but the interpretation of the pollen spectra is complicated due to the mix of the aeolian pollen influx of crop species and species in the surroundings, and of pollen occurring in the used stable fillings. Pollen diagrams and radiocarbon dates of plaggic Anthrosols suggested a development period of more than a millennium. Calluna is present in almost all the pollen spectra, indicating the presence of heath in the landscape during the whole period of soil development. Optically stimulated luminescence dating of the plaggic horizon made clear that the deposition of plaggic covers started in the 16th century and accelerated in the 18th century. The stable fillings, used for the production of plaggic manure and responsible for the rise of the soil surface, cannot be identified with pollen diagrams alone. Biomarker analyses provide more evidence about the sources of stable fillings. The oldest biomarker spectra of the plaggic horizons of three typical plaggic Anthrosols examined in this study were dominated by biomarkers of forest species such as Quercus and Betula while the spectra of middle part of the plaggic horizons were dominated by biomarkers of stem tissue of crop species such as Secale and Avena. Only the youngest spectra of the plaggic horizons were dominated by biomarkers of Calluna. This indicates that the use of heath sods as stable filling was most likely introduced very late in the development of the Anthrosols. Before the 19th century the mineral component in plaggic manure cannot be explained by the use of heath sods. We conclude that other sources of materials, containing mineral grains must have been responsible for the raise of the plaggic

  3. Breakdown in the pretext tokamak

    International Nuclear Information System (INIS)

    Data are presented on the application of ion cyclotron resonance RF power to preionization in tokamaks. We applied 0.3-3 kW at 12 MHz to hydrogen and obtained a visible discharge, but found no scaling of breakdown voltage with any parameter we were able to vary. A possible explanation for this, which implies that higher RF power would have been much more effective, is discussed. Finally, we present our investigation of the dV/dt dependence of breakdown voltage in PRETEXT, a phenomenon also seen in JFT-2. The breakdown is discussed in terms of the physics of Townsend discharges

  4. Delaying vortex breakdown by waves

    Science.gov (United States)

    Yao, M. F.; Jiang, L. B.; Wu, J. Z.; Ma, H. Y.; Pan, J. Y.

    1989-03-01

    The effect of spiral waves on delaying vortex breakdown in a tube is studied experimentally and theoretically. When a harmonic oscillation was imposed on one of guiding vanes in the tube, the breakdown was observed to be postponed appreciately. According to the generalized Lagrangian mean theory, proper forcing spiral waves may produce an additional streaming momentum, of which the effect is favorable and similar to an axial suction at downstream end. The delayed breakdown position is further predicted by using nonlinear wave theory. Qualitative agreement between theory and experiment is obtained, and experimental comparison of the effects due to forcing spiral wave and axial suction is made.

  5. Increased power, pulse length, and spectral purity free-electron laser for inverse-Compton X-ray production and laser induced breakdown spectroscopy of thin film photovoltaics

    Science.gov (United States)

    Kowalczyk, Jeremy M.

    The free-electron laser (FEL) system can be configured to produce X-ray or extreme ultraviolet (EUV) light via Compton backscattering and to perform many types of spectroscopy including laser induced breakdown spectroscopy (LIBS). In it's most common incarnation, the FEL is limited by three major factors: average laser power, laser spectral purity, and laser pulse length. Some examples of the limitations that these shortcomings give rise to include limiting the range of remote spectroscopy, degrading spectroscopic precision, and lowering the attainable x-ray flux, respectively. In this work, we explored three methods of improving the FEL. First, a beam expanding optic dubbed the TIRBBE was designed, built, and tested to prevent laser damage to the resonator mirrors and allow for higher average power. This optic had the added benefit of increasing the spectral purity. Second, a intra-cavity etalon filter dubbed the FROZEN FISH was designed, built, and tested to increase spectral purity and eliminate the frequency pulling (tendency of an FEL to pull towards longer wavelengths during a macropulse) all in a high damage threshold, fully wavelength adjustable package. Finally, a laser cooling scheme which allows for extension of the electron beam macropulse used to create the FEL light by counter-acting electron back-heating was explored. The first measurements of the back-heating temperature rise were taken, calculations of the required laser parameters were made, design of the full system was completed, and construction has begun. Experimental work using LIBS to characterize thin film solar cells was also completed in anticipation of using the improved FEL to better characterize such materials. The frequency tunability and picosecond micropulse width of the FEL will allow for exploration of the frequency response of LIBS ablation and fine resolution of the make up of these materials with depth unattainable with a conventional fixed frequency nanosecond pulse laser.

  6. Breakdown theory for bootstrap quantiles

    OpenAIRE

    Singh, Kesar

    1998-01-01

    A general formula for computing the breakdown point in robustness for the $t$th bootstrap quantile of a statistic $T_n$ is obtained. The answer depends on $t$ and the breakdown point of $T_n$. Since the bootstrap quantiles are vital ingredients of bootstrap confidence intervals, the theory has implications pertaining to robustness of bootstrap confidence intervals. For certain $L$ and $M$ estimators, a robustification of bootstrap is suggested via the notion of Winsorization.

  7. Runaway breakdown and electrical discharges in thunderstorms

    Science.gov (United States)

    Milikh, Gennady; Roussel-Dupré, Robert

    2010-12-01

    This review considers the precise role played by runaway breakdown (RB) in the initiation and development of lightning discharges. RB remains a fundamental research topic under intense investigation. The question of how lightning is initiated and subsequently evolves in the thunderstorm environment rests in part on a fundamental understanding of RB and cosmic rays and the potential coupling to thermal runaway (as a seed to RB) and conventional breakdown (as a source of thermal runaways). In this paper, we describe the basic mechanism of RB and the conditions required to initiate an observable avalanche. Feedback processes that fundamentally enhance RB are discussed, as are both conventional breakdown and thermal runaway. Observations that provide clear evidence for the presence of energetic particles in thunderstorms/lightning include γ-ray and X-ray flux intensifications over thunderstorms, γ-ray and X-ray bursts in conjunction with stepped leaders, terrestrial γ-ray flashes, and neutron production by lightning. Intense radio impulses termed narrow bipolar pulses (or NBPs) provide indirect evidence for RB particularly when measured in association with cosmic ray showers. Our present understanding of these phenomena and their enduring enigmatic character are touched upon briefly.

  8. Dielectric breakdown of cell membranes.

    Science.gov (United States)

    Zimmermann, U; Pilwat, G; Riemann, F

    1974-11-01

    With human and bovine red blood cells and Escherichia coli B, dielectric breakdown of cell membranes could be demonstrated using a Coulter Counter (AEG-Telefunken, Ulm, West Germany) with a hydrodynamic focusing orifice. In making measurements of the size distributions of red blood cells and bacteria versus increasing electric field strength and plotting the pulse heights versus the electric field strength, a sharp bend in the otherwise linear curve is observed due to the dielectric breakdown of the membranes. Solution of Laplace's equation for the electric field generated yields a value of about 1.6 V for the membrane potential at which dielectric breakdown occurs with modal volumes of red blood cells and bacteria. The same value is also calculated for red blood cells by applying the capacitor spring model of Crowley (1973. Biophys. J. 13:711). The corresponding electric field strength generated in the membrane at breakdown is of the order of 4 . 10(6) V/cm and, therefore, comparable with the breakdown voltages for bilayers of most oils. The critical detector voltage for breakdown depends on the volume of the cells. The volume-dependence predicted by Laplace theory with the assumption that the potential generated across the membrane is independent of volume, could be verified experimentally. Due to dielectric breakdown the red blood cells lose hemoglobin completely. This phenomenon was used to study dielectric breakdown of red blood cells in a homogeneous electric field between two flat platinum electrodes. The electric field was applied by discharging a high voltage storage capacitor via a spark gap. The calculated value of the membrane potential generated to produce dielectric breakdown in the homogeneous field is of the same order as found by means of the Coulter Counter. This indicates that mechanical rupture of the red blood cells by the hydrodynamic forces in the orifice of the Coulter Counter could also be excluded as a hemolysing mechanism. The detector

  9. Electrical breakdown in tissue electroporation.

    Science.gov (United States)

    Guenther, Enric; Klein, Nina; Mikus, Paul; Stehling, Michael K; Rubinsky, Boris

    2015-11-27

    Electroporation, the permeabilization of the cell membrane by brief, high electric fields, has become an important technology in medicine for diverse application ranging from gene transfection to tissue ablation. There is ample anecdotal evidence that the clinical application of electroporation is often associated with loud sounds and extremely high currents that exceed the devices design limit after which the devices cease to function. The goal of this paper is to elucidate and quantify the biophysical and biochemical basis for this phenomenon. Using an experimental design that includes clinical data, a tissue phantom, sound, optical, ultrasound and MRI measurements, we show that the phenomenon is caused by electrical breakdown across ionized electrolysis produced gases near the electrodes. The breakdown occurs primarily near the cathode. Electrical breakdown during electroporation is a biophysical phenomenon of substantial importance to the outcome of clinical applications. It was ignored, until now.

  10. 2′-Deoxyriboguanylurea, the primary breakdown product of 5-aza-2′-deoxyribocytidine, is a mutagen, an epimutagen, an inhibitor of DNA methyltransferases and an inducer of 5-azacytidine-type fragile sites

    Science.gov (United States)

    Lamparska, Katarzyna; Clark, Jarrod; Babilonia, Gail; Bedell, Victoria; Yip, Wesley; Smith, Steven S.

    2012-01-01

    5-Aza-2′-deoxycytidine (5azaC-dR) has been employed as an inhibitor of DNA methylation, a chemotherapeutic agent, a clastogen, a mutagen, an inducer of fragile sites and a carcinogen. However, its effects are difficult to quantify because it rapidly breaks down in aqueous solution to the stable compound 2′-deoxyriboguanylurea (GuaUre-dR). Here, we used a phosphoramidite that permits the introduction of GuaUre-dR at defined positions in synthetic oligodeoxynucleotides to demonstrate that it is a potent inhibitor of human DNA methyltransferase 1 (hDNMT1) and the bacterial DNA methyltransferase (M.EcoRII) and that it is a mutagen that can form productive base pairs with either Guanine or Cytosine. Pure GuaUre-dR was found to be an effective demethylating agent and was able to induce 5azaC-dR type fragile sites FRA1J and FRA9E in human cells. Moreover, we report that demethylation associated with C:G → G:C transversion and C:G → T:A transition mutations was observed in human cells exposed to pure GuaUre-dR. The data suggest that most of the effects attributed to 5azaC-dR are exhibited by its stable primary breakdown product. PMID:22850746

  11. Simultaneous characterization of elemental segregation and cementite networks in high carbon steel products by spatially-resolved laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The reliable characterization of the level of elemental segregation and of the extent of grain-boundary cementite networks in high carbon steel products is a prerequisite for checking product quality, for the purpose of product release to customers, and to investigate the presence of defects that may have led to mechanical property failure of the product. Current methods for the characterization of segregation and cementite networks rely on two different methods of sample etching followed by visual observation, where quality scores are given based on human perception and judgment. With the continuous demand on increasing quality, some of the conventional characterization methods and their associated scoring boards have lost relevance for the precision of characterization that is required today to distinguish between a product that will perform well and one that will not. In order to move away from a qualitative, human perception based situation for the scoring of the severity of segregation and cementite networks, a new method of data evaluation based on spatially-resolved LIBS measurements was developed to provide quantitative and simultaneous characterization of both types of defects. The quantitative assessment of segregation and cementite networks is based on the acquisition of carbon concentration maps. The ability to produce rapid scanning measurements of micro and macro-scale features with adequate spatial resolution makes LIBS the measurement method of preference for this purpose. The characterization of both different defects is extracted simultaneously and from the same carbon concentration map following a series of statistical treatment and data extraction rules. LIBS results were validated against recognized methods and were applied to a significant number of routine samples. The new LIBS method offers a step change improvement in reliability for the characterization of segregation and cementite networks in steel products over the conventional methods

  12. Enhancing productivity, eliminate breakdowns on the roofs and solar plants; Potenciando la productividad. Eliminar averias en la cubiertas y plants solares

    Energy Technology Data Exchange (ETDEWEB)

    Benitez Martinez, J.

    2011-07-01

    To date in the photovoltaic industry, the usual practice is being used more traditional methods of preventive maintenance. In addition there is a widespread myth among some producers and sites in the maintainers to take for non-valid need for eternal function facilities and as much is necessary to clean the panels to improve production. (Author)

  13. The Breakdown of Morale

    NARCIS (Netherlands)

    N. Vikander (Nick)

    2009-01-01

    textabstractThis paper studies how morale in teams can break down. It interprets high morale as team members working together productively, either because of a sense of fairness or because of implicit incentives from repeated interactions. Team members learn that lay-offs will occur at a fixed futur

  14. The influence of the gaseous by-products from detonation and inert additives to explosives on the efficiency of mining rock breakdown

    Energy Technology Data Exchange (ETDEWEB)

    Komir, V.M.; Chebenko, V.N.; Napadailo, V.I.; Rodak, S.N.

    1981-01-01

    Results are given from experiments to determine the influence of inert additives to explosives on the intensity of crushing mining rock. The mechanism of the blast action during the destruction of the samples using carbonic acid and sand as the additives is examined. An analysis of the experimental results demonstrated that the disjoining action of the detonation products is the result of the determinate role of the radial cracks in increasing the radius of the zone--these waves are generated by the shock wave. The efficiency of the blast may be increased by using easily-decomposing additives in the explosive that during explosion, evaporate, and both give off a large amount of gas and decrease the temperature of the detonation products, and consequently, the intensity of heat exchange with the rock.

  15. Threshold criteria for undervoltage breakdown

    Science.gov (United States)

    Cooley, James E.; Choueiri, Edgar Y.

    2008-05-01

    The conditions under which an externally supplied pulse of electrons will induce breakdown in an undervoltaged, low-gain discharge gap are experimentally and theoretically explored. The minimum number of injected electrons required to achieve breakdown in a parallel-plate gap is measured in argon at pd values of 3-10 Torr m using ultraviolet laser pulses to photoelectrically release electrons from the cathode. This value was found to scale inversely with voltage at constant pd and with pressure within the parameter range explored. A dimensionless theoretical description of the phenomenon is formulated and numerically solved. It is found that a significant fraction of the charge on the plates must be injected for breakdown to be achieved at low gain. It is also found that fewer electrons are required as the gain due to electron-impact ionization (α process) is increased, or as the sensitivity of the α process to electric field is enhanced by increasing the gas pressure. A predicted insensitivity to ion mobility implies that the breakdown is determined during the first electron avalanche when space-charge distortion is greatest.

  16. [Novel biomarkers for diabetic nephropathy].

    Science.gov (United States)

    Araki, Shin-ichi

    2014-02-01

    Diabetic nephropathy is a leading cause of end-stage renal disease worldwide. An early clinical sign of this complication is an increase of urinary albumin excretion, called microalbuminuria, which is not only a predictor of the progression of nephropathy, but also an independent risk factor for cardiovascular disease. Although microalbuminuria is clinically important to assess the prognosis of diabetic patients, it may be insufficient as an early and specific biomarker of diabetic nephropathy because of a large day-to-day variation and lack of a good correlation of microalbuminuria with renal dysfunction and pathohistological changes. Thus, more sensitive and specific biomarkers are needed to improve the diagnostic capability of identifying patients at high risk. The factors involved in renal tubulo-interstitial damage, the production and degradation of extracellular matrix, microinflammation, etc., are investigated as candidate molecules. Despite numerous efforts so far, the assessment of these biomarkers is still a subject of ongoing investigations. Recently, a variety of omics and quantitative techniques in systems biology are rapidly emerging in the field of biomarker discovery, including proteomics, transcriptomics, and metabolomics, and they have been applied to search for novel putative biomarkers of diabetic nephropathy. Novel biomarkers or their combination with microalbuminuria provide a better diagnostic accuracy than microalbuminuria alone, and may be useful for establishing personal medicine. Furthermore, the identification of novel biomarkers may provide insight into the mechanisms underlying diabetic nephropathy.

  17. Post-glacial variability of sea ice cover, river run-off and biological production in the western Laptev Sea (Arctic Ocean) - A high-resolution biomarker study

    Science.gov (United States)

    Hörner, T.; Stein, R.; Fahl, K.; Birgel, D.

    2016-07-01

    Multi-proxy biomarker measurements were applied on two sediment cores (PS51/154, PS51/159) to reconstruct sea ice cover (IP25), biological production (brassicasterol, dinosterol) and river run-off (campesterol, β-sitosterol) in the western Laptev Sea over the last ∼17 ka with unprecedented temporal resolution. The absence of IP25 from 17.2 to 15.5 ka, in combination with minimum concentration of phytoplankton biomarkers, suggests that the western Laptev Sea shelf was mostly covered with permanent sea ice. Very minor river run-off and restricted biological production occurred during this cold interval. From ∼16 ka until 7.5 ka, a long-term decrease of terrigenous (riverine) organic matter and a coeval increase of marine organic matter reflect the gradual establishment of fully marine conditions in the western Laptev Sea, caused by the onset of the post-glacial transgression. Intensified river run-off and reduced sea ice cover characterized the time interval between 15.2 and 12.9 ka, including the Bølling/Allerød warm period (14.7-12.9 ka). Prominent peaks of the DIP25 Index coinciding with maximum abundances of subpolar foraminifers, are interpreted as pulses of Atlantic water inflow on the western Laptev Sea shelf. After the warm period, a sudden return to severe sea ice conditions with strongest ice-coverage between 11.9 and 11 ka coincided with the Younger Dryas (12.9-11.6 ka). At the onset of the Younger Dryas, a distinct alteration of the ecosystem (reflected in a distinct drop in terrigenous and phytoplankton biomarkers) was detected. During the last 7 ka, the sea ice proxies reflect a cooling of the Laptev Sea spring/summer season. This cooling trend was superimposed by a short-term variability in sea ice coverage, probably representing Bond cycles (1500 ± 500 ka) that are related to solar activity changes. Hence, atmospheric circulation changes were apparently able to affect the sea ice conditions on the Laptev Sea shelf under modern sea level

  18. Protein breakdown in cancer cachexia.

    Science.gov (United States)

    Sandri, Marco

    2016-06-01

    Skeletal muscle is a highly adaptive tissue, capable of altering muscle fiber size, functional capacity and metabolism in response to physiological stimuli. However, pathological conditions such as cancer growth compromise the mechanisms that regulate muscle homeostasis, resulting in loss of muscle mass, functional impairment and compromised metabolism. This tumor-induced condition is characterized by enhanced muscle protein breakdown and amino acids release that sustain liver gluconeogenesis and tissue protein synthesis. Proteolysis is controlled by the two most important cellular degradation systems, the ubiquitin proteasome and autophagy lysosome. These systems are carefully regulated by different signalling pathways that determine protein and organelle turnover. In this review we will describe the involvement of the ubiquitin proteasome and autophagy lysosome systems in cancer cachexia and the principal signalling pathways that regulate tumor-induced protein breakdown in muscle. PMID:26564688

  19. Standardization of natural mycolic acid antigen composition and production for use in biomarker antibody detection to diagnose active tuberculosis.

    Science.gov (United States)

    Ndlandla, F L; Ejoh, V; Stoltz, A C; Naicker, B; Cromarty, A D; van Wyngaardt, S; Khati, M; Rotherham, L S; Lemmer, Y; Niebuhr, J; Baumeister, C R; Al Dulayymi, J R; Swai, H; Baird, M S; Verschoor, J A

    2016-08-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, is characterized by the abundance of species specific, antigenic cell wall lipids called mycolic acids. These wax-like molecules all share an identical, amphiphilic mycolic motif, but have different functional groups in a long hydrophobic hydrocarbon mero-chain that divide them into three main classes: alpha-, keto- and methoxy-mycolic acids. Whereas alpha-mycolic acids constitutively maintain an abundance of around 50%, the ratio of methoxy- to keto-mycolic acid types may vary depending on, among other things, the growth stage of M. tuberculosis. In human patients, antibodies to mycolic acids have shown potential as diagnostic serum biomarkers for active TB. Variations in mycolic acid composition affect the antigenic properties and can potentially compromise the precision of detection of anti-mycolic acids antibodies in patient sera to natural mixtures. We demonstrate this here with combinations of synthetic mycolic acid antigens, tested against TB patient and control sera. Combinations of methoxy- and α-mycolic acids are more antigenic than combinations of keto- and α-mycolic acids, showing the former to give a more sensitive test for TB biomarker antibodies. Natural mixtures of mycolic acids isolated from mature cultures of M. tuberculosis H37Rv give the same sensitivity as that with synthetic methoxy- and α-mycolic acids in combination, in a surface plasmon resonance inhibition biosensor test. To ensure that the antigenic activity of isolates of natural mycolic acids is reproducible, we cultured M. tuberculosis H37Rv on Middlebrook 7H10 solid agar plates to stationary growth phase in a standardized, optimal way. The proportions of mycolic acid classes in various batches of the isolates prepared from these cultures were compared to a commercially available natural mycolic acid isolate. LC-MS/MS and NMR data for quantitation of mycolic acids class compositions show that the variation in batches

  20. Tune in, breakdown, and reboot

    OpenAIRE

    Pedersen, Michael

    2009-01-01

    Routine work‐process, lack of self‐management, and long work‐hours have traditionally been the main topics of discussion within the occupational stress literature, constituting the primary factors that make people breakdown and burn out. But within the last couple of years, this discussion has expanded its focus from issues concerning the disciplinary work‐space. Increasing attention is now being placed on the problems related to the burgeoning interest in employee empowerme...

  1. Individual breakdown of pension rights

    CERN Multimedia

    2016-01-01

    You should have recently received, via email, your “Individual breakdown of pension rights”.   Please note that: the calculation was based on data as at 1st July 2016, as at 1st September 2016, CERN will introduce a new career structure; the salary position will now be expressed as a percentage of a midpoint of a grade.   We would like to draw your attention to the fact that your pension rights will remain unchanged. Benefits Service CERN Pension Fund

  2. DC breakdown experiments with cobalt electrodes

    CERN Document Server

    Descoeudres, Antoine; Nordlund, Kai

    2009-01-01

    RF accelerating structures of the Compact Linear Collider (CLIC) require a material capable of sustaining high electric field with a low breakdown rate and low induced damage. Because of the similarity of many aspects of DC and RF breakdown, a DC breakdown study is underway at CERN in order to test candidate materials and surface preparations, and have a better understanding of the breakdown mechanism under ultra-high vacuum in a simple setup. The conditioning speed, breakdown field and field enhancement factor of cobalt have been measured. The average breakdown field after conditioning reaches 615 MV/m, which places cobalt amongst the best materials tested so far. By comparison with results and properties of other metals, the high breakdown field of Co could be due to its high work function and maybe also to its hexagonal crystal structure. Geneva, Switzerland (June 2009) CLIC – Note – 875

  3. Biomarkers of Ovarian Reserve

    Directory of Open Access Journals (Sweden)

    William E. Roudebush

    2008-01-01

    Full Text Available The primary function of the female ovary is the production of a mature and viable oocyte capable of fertilization and subsequent embryo development and implantation. At birth, the ovary contains a finite number of oocytes available for folliculogenesis. This finite number of available oocytes is termed “the ovarian reserve”. The determination of ovarian reserve is important in the assessment and treatment of infertility. As the ovary ages, the ovarian reserve will decline. Infertility affects approximately 15-20% of reproductive aged couples. The most commonly used biomarker assay to assess ovarian reserve is the measurement of follicle stimulating hormone (FSH on day 3 of the menstrual cycle. However, antimüllerian hormone and inhibin-B are other biomarkers of ovarian reserve that are gaining in popularity since they provide direct determination of ovarian status, whereas day 3 FSH is an indirect measurement. This review examines the physical tools and the hormone biomarkers used to evaluate ovarian reserve.

  4. Environmental assessment after decommissioning at the North Sea- Froey oil production site: a field study with biomarkers in fish and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Pinturier, Laurence; Beyer, Jonny; Moltu, Ulf; Plisson, Saune Stephan; Berland, Harald; Sundt, Rolf; Bjoernstad, Anne; Sanni, Steinar

    2006-03-15

    The Froey field is situated in the North Sea and was operated by Total Exploration and Production Norge. Oil production started in 1995 and ceased in 2001, when the wells were permanently plugged and abandoned. The jacket was removed in 2002, and in 2003 the first post-production sediment monitoring survey was carried out at the field as a part of the regional sediment environmental monitoring survey of Region II. In parallel to the sediment monitoring survey and cuttings survey, Total E and P Norge decided to conduct an environmental survey based on the use of biological effects parameters (or biomarkers) to document the environmental condition of the site after decommissioning. A series of pollutant responsive biomarkers was selected in order to answer the following questions: is the environmental condition in the bottom water at the Froey location significantly different to the background situation as measured in the reference station? And does the cutting deposit affect the nearby environment. Conclusion: This paper present a selection of the results obtained during an environmental survey carried out at a decommissioned field, the Froey field, by Total E and P Norge and RF-Akvamiljoe. Detailed results and discussion will be presented more extensively in a peer review publication by Beyer et al. (2005). The objective of the survey was to evaluate the environmental condition at the Froey site by comparing it to a background situation measured at a reference site. The environmental condition was assessed by measuring biological effects parameters in invertebrates and fish living in close connection with the sediments. The results of this survey indicate only a very local pollutant effect in the vicinity of the cuttings limited to the invertebrates living and feeding on the sediment. No signal effects were measured in the selected fish species known to swallow large quantity of sediment when feeding. These results corroborate well the ones obtained from the

  5. The Development of Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2007-01-01

    Full Text Available The conditions under which breakdown of composite liquid - solid insulation can be occurred, e.g. in transformer, play an important role in designing of such insulation. The initial state of breakdown development is explained based on development of streamers in cavitations. The whole breakdown development in transformer oil is represented by RLC circuit and it depends on the parameters of outer circuit.

  6. On exponential growth [of gas breakdown

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1991-01-01

    The agreement obtained between measured breakdown voltages and predicted breakdown values is frequently used as a means of assessing the validity of the theory/model in question. However, owing to the mathematical nature of exponential growth, it is easy to formulate a criterion that provides acc...... acceptable breakdown values, although the criterion may contain totally unrealistic features. An example from the work of A. Pedersen (1989) showing unrestricted exponential growth in SF 6 is used to highlight the insensitivity of breakdown voltages with respect to modeling...

  7. Diagnostic protein biomarkers for severe, moderate and mild traumatic brain injury

    Science.gov (United States)

    Streeter, Jackson; Hayes, Ronald L.; Wang, Kevin K. W.

    2011-06-01

    Traumatic Brain Injury (TBI) is a major problem in military and civilian medicine. Yet, there are no simple non-invasive diagnostics for TBI. Our goal is to develop and clinically validate blood-based biomarker assays for the diagnosis, prognosis and management of mild, moderate and severe TBI patients. These assays will ultimately be suitable for deployment to far-forward combat environments. Using a proteomic and systems biology approach, we identified over 20 candidate biomarkers for TBI and developed robust ELISAs for at least 6 candidate biomarkers, including Ubiquitin C-terminal hydrolase- L1 (UCH-L1), Glial Fibrillary Acidic Protein (GFAP) and a 145 kDa breakdown products of αII-spectrin (SBDP 145) generated by calpain proteolysis. In a multi-center feasibility study (Biomarker Assessment For Neurotrauma Diagnosis And Improved Triage System (BANDITS), we analyzed CSF and blood samples from 101 adult patients with severe TBI [Glasgow Coma Scale (GCS) <= 8] at 6 sites and analyzed 27 mild TBI patients and 5 moderate TBI patients [GCS 9-15] from 2 sites in a pilot study. We identified that serum levels of UCH-L1, GFAP and SBDP145 have strong diagnostic and prognostic properties for severe TBI over controls. Similarly initial post-TBI serum levels (< 6 h) of UCH-L1 and GFAP have diagnostic characteristics for moderate and mild TBI. We are now furthering assay production, refining assay platforms (both benchtop and point-ofcare/ handheld) and planning a pivotal clinical study to seek FDA approval of these TBI diagnostic assays.

  8. Biomarkers of Brain Damage and Postoperative Cognitive Disorders in Orthopedic Patients: An Update

    Directory of Open Access Journals (Sweden)

    Dariusz Tomaszewski

    2015-01-01

    Full Text Available The incidence of postoperative cognitive dysfunction (POCD in orthopedic patients varies from 16% to 45%, although it can be as high as 72%. As a consequence, the hospitalization time of patients who developed POCD was longer, the outcome and quality of life were worsened, and prolonged medical and social assistance were necessary. In this review the short description of such biomarkers of brain damage as the S100B protein, NSE, GFAP, Tau protein, metalloproteinases, ubiquitin C terminal hydrolase, microtubule-associated protein, myelin basic protein, α-II spectrin breakdown products, and microRNA was made. The role of thromboembolic material in the development of cognitive decline was also discussed. Special attention was paid to optimization of surgical and anesthetic procedures in the prevention of postoperative cognitive decline.

  9. Occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in Oligocene sediments from the Mallik 5L-38 Gas Hydrate Production Research Well (Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Haberer, R.M.; Mangelsdorf, K.; Wilkes, H.; Horsfield, B. [Geoforschungszentrum Potsdam, Potsdam (Germany)

    2006-07-01

    The aromatic hydrocarbon biomarker distributions of thirty Oligocene sediment samples with different lithology (lignite, clay and sand) from the JAPEX/JNOC/GSC et al. Mallik 5L-38 Gas Hydrate Production Research Well, Canada, were analyzed using gas chromatography-mass spectrometry (GC-MS). The compositions vary with lithology, indicating a change in palaeoenvironmental conditions at the time of deposition. Aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm (e.g., conifer) dominated palaeovegetation. In contrast, in the clay samples aromatic triterpenoids are generally preserved as major constituents, indicating angiosperm dominated vegetation. The sand samples contain only minor amounts of aromatic terpenoids, but show a preference for diterpenoid gymnosperm markers. To recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio, termed the angiosperm-gymnosperm aromatic ratio (AGAR), has been developed. Thus, the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the Mallik site (lignites) and the hinterland (clays) over time. Concomitantly, the changing dominance in the plant communities allows an insight into varying climatic conditions during the late Oligocene in the area.

  10. Biomarkers in Computational Toxicology

    Science.gov (United States)

    Biomarkers are a means to evaluate chemical exposure and/or the subsequent impacts on toxicity pathways that lead to adverse health outcomes. Computational toxicology can integrate biomarker data with knowledge of exposure, chemistry, biology, pharmacokinetics, toxicology, and e...

  11. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-01

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis. PMID:26787907

  12. Combination of biomarkers

    DEFF Research Database (Denmark)

    Thurfjell, Lennart; Lötjönen, Jyrki; Lundqvist, Roger;

    2012-01-01

    The New National Institute on Aging-Alzheimer's Association diagnostic guidelines for Alzheimer's disease (AD) incorporate biomarkers in the diagnostic criteria and suggest division of biomarkers into two categories: Aβ accumulation and neuronal degeneration or injury.......The New National Institute on Aging-Alzheimer's Association diagnostic guidelines for Alzheimer's disease (AD) incorporate biomarkers in the diagnostic criteria and suggest division of biomarkers into two categories: Aβ accumulation and neuronal degeneration or injury....

  13. Identification of a novel lipid biomarker in lake sediments: Implications for the aquatic production of branched GDGTs

    Science.gov (United States)

    Weber, Yuki; De Jonge, Cindy; Rijpstra, W. Irene C.; Hopmans, Ellen C.; Stadnitskaia, Alina; Schubert, Carsten J.; Lehmann, Moritz F.; Sinninghe Damsté, Jaap S.; Niemann, Helge

    2014-05-01

    Branched dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that occur ubiquitously in soils worldwide. Their relative abundances (which form the MBT and CBT indices) correlate with mean annual air temperature (MAAT) and pH, making them potential proxies for paleoenvironmental reconstructions in sedimentary archives with organic matter input of from terrestrial environments. In lake sediments, however, brGDGT distributions mostly relate differently to MAAT compared to soils. A likely cause for this discrepancy is in situ production of brGDGTs within the lake water column and/or -sediments by microorganisms possessing a membrane physiology that is different from soil bacteria. Until to date, existing analytical methods did not allow the distinction between soil-and lake-derived brGDGTs, complicating paleoclimate reconstructions in lacustrine settings. In order to decipher differences in the structure and the relative distribution of brGDGTs in lake deposits versus soils, we analysed samples from 35 Swiss alpine lakes and their catchments using an improved HPLC protocol. Our data revealed a novel isomer of the hexamethylated, non-cyclic brGDGT, which was previously co-eluting with the recently described 5- and 6-methyl isomers. About half of the 35 investigated lakes contained this compound where it accounted for 1 - 11 % of total brGDGTs. We were able to isolate the previously unknown isomer by multi-step preparative HPLC. The structure of the molecule was assessed by determining the identity of its alkyl chains by ether cleavage with HI and subsequent analysis with gas chromatography quadrupole mass spectrometry (GC-MS). In addition, the carbon isotopic composition of the fragments was determined to trace their biological source. In contrast to lake sediments, soil samples analysed from the watersheds of the studied lakes did not contain the newly discovered GDGT, providing evidence for in situ production in aquatic systems. This novel isomer is

  14. New sepsis biomarkers

    Institute of Scientific and Technical Information of China (English)

    Dolores Limongi; Cartesio DAgostini; Marco Ciotti

    2016-01-01

    Sepsis remains a leading cause of death in the intensive care units and in all age groups worldwide. Early recognition and diagnosis are key to achieving improved outcomes. Therefore, novel biomarkers that might better inform clinicians treating such patients are surely needed. The main attributes of successful biomarkers would be high sensitivity, specificity, possibility of bedside monitoring and financial accessibility. A panel of sepsis biomarkers along with currently used laboratory tests will facilitate earlier diagnosis, timely treatment and improved outcome may be more effective than single biomarkers. In this review, we summarize the most recent advances on sepsis biomarkers evaluated in clinical and experimental studies.

  15. Scintillation Breakdowns in Chip Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2008-01-01

    Scintillations in solid tantalum capacitors are momentarily local breakdowns terminated by a self-healing or conversion to a high-resistive state of the manganese oxide cathode. This conversion effectively caps the defective area of the tantalum pentoxide dielectric and prevents short-circuit failures. Typically, this type of breakdown has no immediate catastrophic consequences and is often considered as nuisance rather than a failure. Scintillation breakdowns likely do not affect failures of parts under surge current conditions, and so-called "proofing" of tantalum chip capacitors, which is a controllable exposure of the part after soldering to voltages slightly higher than the operating voltage to verify that possible scintillations are self-healed, has been shown to improve the quality of the parts. However, no in-depth studies of the effect of scintillations on reliability of tantalum capacitors have been performed so far. KEMET is using scintillation breakdown testing as a tool for assessing process improvements and to compare quality of different manufacturing lots. Nevertheless, the relationship between failures and scintillation breakdowns is not clear, and this test is not considered as suitable for lot acceptance testing. In this work, scintillation breakdowns in different military-graded and commercial tantalum capacitors were characterized and related to the rated voltages and to life test failures. A model for assessment of times to failure, based on distributions of breakdown voltages, and accelerating factors of life testing are discussed.

  16. Breakdown characteristics of xenon HID Lamps

    Science.gov (United States)

    Babaeva, Natalia; Sato, Ayumu; Brates, Nanu; Noro, Koji; Kushner, Mark

    2009-10-01

    The breakdown characteristics of mercury free xenon high intensity discharge (HID) lamps exhibit a large statistical time lag often having a large scatter in breakdown voltages. In this paper, we report on results from a computational investigation of the processes which determine the ignition voltages for positive and negative pulses in commercial HID lamps having fill pressures of up to 20 atm. Steep voltage rise results in higher avalanche electron densities and earlier breakdown times. Circuit characteristics also play a role. Large ballast resistors may limit current to the degree that breakdown is quenched. The breakdown voltage critically depends on cathode charge injection by electric field emission (or other mechanisms) which in large part controls the statistical time lag for breakdown. For symmetric lamps, ionization waves (IWs) simultaneously develop from the bottom and top electrodes. Breakdown typically occurs when the top and bottom IWs converge. Condensed salt layers having small conductivities on the inner walls of HID lamps and on the electrodes can influence the ignition behavior. With these layers, IWs tend to propagate along the inner wall and exhibit a different structure depending on the polarity.

  17. Breakdown of Benford's Law for Birth Data

    CERN Document Server

    Ausloos, M; Ileanu, B

    2014-01-01

    Long birth time series for Romania are investigated from Benford's law point of view, distinguishing between families with a religious (Orthodox and Non-Orthodox) affiliation. The data extend from Jan. 01, 1905 till Dec. 31, 2001, i.e. over 97 years or 35 429 days. The results point to a drastic breakdown of Benford's law. Some interpretation is proposed, based on the statistical aspects due to population sizes, rather than on human thought constraints when the law breakdown is usually expected. Benford's law breakdown clearly points to natural causes.

  18. Biomarkers of oxidative stress in antioxidant therapy

    Directory of Open Access Journals (Sweden)

    Wilfredo Mañon Rossi

    2016-04-01

    Full Text Available Biomarkers are used regularly in medical practice to provide objective markers of health status of a person, as well as the physiological response of the body to a pharmacological therapeutic intervention. In the specific case of the use of antioxidant products (antioxidant therapy, it is necessary to measure both biomarkers of oxidative stress level of the person as those that are specific to a physiological or pathological progression of a disease disorder. This paper describes the main biomarkers of oxidative general and specific stress as well as laboratory techniques, which should be taken into account when measuring the effectiveness of antioxidant therapies.

  19. Biomarkers in T cell therapy clinical trials

    Directory of Open Access Journals (Sweden)

    Kalos Michael

    2011-08-01

    Full Text Available Abstract T cell therapy represents an emerging and promising modality for the treatment of both infectious disease and cancer. Data from recent clinical trials have highlighted the potential for this therapeutic modality to effect potent anti-tumor activity. Biomarkers, operationally defined as biological parameters measured from patients that provide information about treatment impact, play a central role in the development of novel therapeutic agents. In the absence of information about primary clinical endpoints, biomarkers can provide critical insights that allow investigators to guide the clinical development of the candidate product. In the context of cell therapy trials, the definition of biomarkers can be extended to include a description of parameters of the cell product that are important for product bioactivity. This review will focus on biomarker studies as they relate to T cell therapy trials, and more specifically: i. An overview and description of categories and classes of biomarkers that are specifically relevant to T cell therapy trials, and ii. Insights into future directions and challenges for the appropriate development of biomarkers to evaluate both product bioactivity and treatment efficacy of T cell therapy trials.

  20. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  1. Novel diagnostic biomarkers for prostate cancer

    Directory of Open Access Journals (Sweden)

    Chikezie O. Madu, Yi Lu

    2010-01-01

    Full Text Available Prostate cancer is the most frequently diagnosed malignancy in American men, and a more aggressive form of the disease is particularly prevalent among African Americans. The therapeutic success rate for prostate cancer can be tremendously improved if the disease is diagnosed early. Thus, a successful therapy for this disease depends heavily on the clinical indicators (biomarkers for early detection of the presence and progression of the disease, as well as the prediction after the clinical intervention. However, the current clinical biomarkers for prostate cancer are not ideal as there remains a lack of reliable biomarkers that can specifically distinguish between those patients who should be treated adequately to stop the aggressive form of the disease and those who should avoid overtreatment of the indolent form.A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. A biomarker reveals further information to presently existing clinical and pathological analysis. It facilitates screening and detecting the cancer, monitoring the progression of the disease, and predicting the prognosis and survival after clinical intervention. A biomarker can also be used to evaluate the process of drug development, and, optimally, to improve the efficacy and safety of cancer treatment by enabling physicians to tailor treatment for individual patients. The form of the prostate cancer biomarkers can vary from metabolites and chemical products present in body fluid to genes and proteins in the prostate tissues.Current advances in molecular techniques have provided new tools facilitating the discovery of new biomarkers for prostate cancer. These emerging biomarkers will be beneficial and critical in developing new and clinically reliable indicators that will have a high specificity for the diagnosis and prognosis of

  2. Novel diagnostic biomarkers for prostate cancer.

    Science.gov (United States)

    Madu, Chikezie O; Lu, Yi

    2010-10-06

    Prostate cancer is the most frequently diagnosed malignancy in American men, and a more aggressive form of the disease is particularly prevalent among African Americans. The therapeutic success rate for prostate cancer can be tremendously improved if the disease is diagnosed early. Thus, a successful therapy for this disease depends heavily on the clinical indicators (biomarkers) for early detection of the presence and progression of the disease, as well as the prediction after the clinical intervention. However, the current clinical biomarkers for prostate cancer are not ideal as there remains a lack of reliable biomarkers that can specifically distinguish between those patients who should be treated adequately to stop the aggressive form of the disease and those who should avoid overtreatment of the indolent form.A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. A biomarker reveals further information to presently existing clinical and pathological analysis. It facilitates screening and detecting the cancer, monitoring the progression of the disease, and predicting the prognosis and survival after clinical intervention. A biomarker can also be used to evaluate the process of drug development, and, optimally, to improve the efficacy and safety of cancer treatment by enabling physicians to tailor treatment for individual patients. The form of the prostate cancer biomarkers can vary from metabolites and chemical products present in body fluid to genes and proteins in the prostate tissues.Current advances in molecular techniques have provided new tools facilitating the discovery of new biomarkers for prostate cancer. These emerging biomarkers will be beneficial and critical in developing new and clinically reliable indicators that will have a high specificity for the diagnosis and prognosis of prostate cancer. The

  3. Breakdown Point Theory for Implied Probability Bootstrap

    OpenAIRE

    Lorenzo Camponovo; Taisuke Otsu

    2011-01-01

    This paper studies robustness of bootstrap inference methods under moment conditions. In particular, we compare the uniform weight and implied probability bootstraps by analyzing behaviors of the bootstrap quantiles when outliers take arbitrarily large values, and derive the breakdown points for those bootstrap quantiles. The breakdown point properties characterize the situation where the implied probability bootstrap is more robust than the uniform weight bootstrap against outliers. Simulati...

  4. Humidity effects on wire insulation breakdown strength.

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  5. Salivary biomarkers in psychobiological medicine

    OpenAIRE

    Chiappelli, Francesco; Iribarren, Francisco Javier; Prolo, Paolo

    2006-01-01

    The value of salivary biomarkers for diagnostic and prognostic assessments has become increasingly well established in medicine, pharmacology, and dentistry. Certain salivary components mirror the neuro-endocrine status of the organism. Other saliva products are protein in nature, and can serve to reflect immune surveillance processes. The autonomic nervous system regulates the process of salivation, and the concentration of yet other salivary components, such as α-amylase, which provide a re...

  6. Effect of magnetic nanoparticles on the lightning impulse breakdown voltage of transformer oil

    Science.gov (United States)

    Ghasemi, J.; Jafarmadar, S.; Nazari, M.

    2015-09-01

    In this study, the lightning impulse breakdown voltage of magnetic nanofluids based on transformer mineral oil for use in power systems was reviewed. Magnetic nanofluids are obtained from dispersion of the magnetic nanoparticles (Fe3 O4) within transformer oil, as the base fluid. The Fe3 O4 nanoparticles, using a coprecipitation method, were synthesized, coated with a surfactant, and dispersed using an ultrasonic processor, within the uninhibited transformer mineral oil NYTRO LIBRA. The lightning impulse breakdown voltage was obtained using sphere-sphere electrodes in an experimental setup for nano-oil, in volume concentration of 0.1-0.6%. Results indicate improved lightning impulse breakdown voltage under optimal conditions. Increase in the lightning impulse breakdown voltage of the nano-oil is mainly due to the dielectric and magnetic properties of Fe3 O4 nanoparticles, acting as free electrons snapper, and reduce the rate of free electrons production in the ionization process.

  7. Measuring protein breakdown rate in individual proteins in vivo

    DEFF Research Database (Denmark)

    Holm, Lars; Kjaer, Michael

    2010-01-01

    To outline different approaches of how protein breakdown can be quantified and to present a new approach to determine the fractional breakdown rate of individual slow turnover proteins in vivo.......To outline different approaches of how protein breakdown can be quantified and to present a new approach to determine the fractional breakdown rate of individual slow turnover proteins in vivo....

  8. [Galactomannan breakdown in germinating carob seeds (Ceratonia siliqua L.)].

    Science.gov (United States)

    Seiler, A

    1977-01-01

    In the first days of germination of carob seeds (Ceratonia siliqua L., Leguminosae) (until penetration of the seed coat by the radicle) oligosaccharides of the raffinose series present in the endosperm and embryo are hydrolysed. The mobilisation of the reserve galactomannan of the endosperm begins after the emergence of the radicle. Its degradation is effected by hydrolytic enzymes (α-galactosidase [EC 3.2.1.22], β-mannanase, [EC 3.2.1.25] and β-mannosidase [EC 3.2.1.25]) and the breakdown products-galactose and mannose-are continuously metabolised by the embryo. At the same time starch synthesis is observed in the embryo.In the germination of Ceratonia siliqua seeds the embryo does not have a direct effect on the mobilisation of the reserve polysaccharide as it does in the case of barley. The endosperm consists of living cells which, independently of the embryo, synthesise the enzymes used for galactomannan breakdown. A weak α-galactosidase activity is already present in the endosperm of mature dry seeds. This activity cannot be suppressed by inhibitors of transcription or translation, so that their presence does not prevent degradation of oligosaccharides of the raffinose series.A high proportion of the α-galactosidase responsible for the breakdown of the galactomannan is synthesised de novo during germination. Such synthesis could be demonstrated by the incorporation of [U-(14)C]serine and could be inhibited by actinomycin D or cycloheximide.

  9. Dielectric breakdown in mineral oil ITO 100 based magnetic fluid

    Science.gov (United States)

    Kudelcik, J.; Bury, P.; Kopcansky, P.; Timko, M.

    The development of dielectric breakdown and the DC dielectric breakdown voltage of magnetic fluids based on inhibited transformer oil ITO 100 were investigated in parallel orientations of external magnetic field. It was shown that the breakdown voltage is strongly influenced by the magnetic nanoparticles. The magnetic fluids with the volume concentration 1and 0.2% had better dielectric properties than pure transformer oil. The increase of breakdown voltage was interpreted on the base of the bubble theory of breakdown.

  10. Associations of serum insulin-like growth factor-I and insulin-like growth factor-binding protein 3 levels with biomarker-calibrated protein, dairy product and milk intake in the Women's Health Initiative.

    Science.gov (United States)

    Beasley, Jeannette M; Gunter, Marc J; LaCroix, Andrea Z; Prentice, Ross L; Neuhouser, Marian L; Tinker, Lesley F; Vitolins, Mara Z; Strickler, Howard D

    2014-03-14

    It is well established that protein-energy malnutrition decreases serum insulin-like growth factor (IGF)-I levels, and supplementation of 30 g of whey protein daily has been shown to increase serum IGF-I levels by 8 % after 2 years in a clinical trial. Cohort studies provide the opportunity to assess associations between dietary protein intake and IGF axis protein levels under more typical eating conditions. In the present study, we assessed the associations of circulating IGF axis protein levels (ELISA, Diagnostic Systems Laboratories) with total biomarker-calibrated protein intake, as well as with dairy product and milk intake, among postmenopausal women enrolled in the Women's Health Initiative (n 747). Analyses were carried out using multivariate linear regression models that adjusted for age, BMI, race/ethnicity, education, biomarker-calibrated energy intake, alcohol intake, smoking, physical activity and hormone therapy use. There was a positive association between milk intake and free IGF-I levels. A three-serving increase in milk intake per d (approximately 30 g of protein) was associated with an estimated average 18·6 % higher increase in free IGF-I levels (95 % CI 0·9, 39·3 %). However, total IGF-I and insulin-like growth factor-binding protein 3 (IGFBP-3) levels were not associated with milk consumption and nor were there associations between biomarker-calibrated protein intake, biomarker-calibrated energy intake, and free IGF-I, total IGF-I or IGFBP-3 levels. The findings of the present study carried out in postmenopausal women are consistent with clinical trial data suggesting a specific relationship between milk consumption and serum IGF-I levels, although in the present study this association was only statistically significant for free, but not total, IGF-I or IGFBP-3 levels.

  11. Respiratory Toxicity Biomarkers

    Science.gov (United States)

    The advancement in high throughput genomic, proteomic and metabolomic techniques have accelerated pace of lung biomarker discovery. A recent growth in the discovery of new lung toxicity/disease biomarkers have led to significant advances in our understanding of pathological proce...

  12. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    International Nuclear Information System (INIS)

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15–20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes

  13. Biomarkers in Autism

    Directory of Open Access Journals (Sweden)

    Robert eHendren

    2014-08-01

    Full Text Available Autism spectrum disorders (ASD are complex, heterogeneous disorders caused by an interaction between genetic vulnerability and environmental factors. In an effort to better target the underlying roots of ASD for diagnosis and treatment, efforts to identify reliable biomarkers in genetics, neuroimaging, gene expression and measures of the body’s metabolism are growing. For this article, we review the published studies of potential biomarkers in autism and conclude that while there is increasing promise of finding biomarkers that can help us target treatment, there are none with enough evidence to support routine clinical use unless medical illness is suspected. Promising biomarkers include those for mitochondrial function, oxidative stress, and immune function. Genetic clusters are also suggesting the potential for useful biomarkers.

  14. Organic biomarker records spanning the last 34,800 years from the southeastern Brazilian upper slope: links between sea surface temperature, displacement of the Brazil Current, and marine productivity

    Science.gov (United States)

    Lourenço, Rafael André; de Mahiques, Michel Michaelovitch; Wainer, Ilana Elazari Klein Coaracy; Rosell-Melé, Antoni; Bícego, Márcia Caruso

    2016-10-01

    Collective assessment of marine and terrigenous organic biomarkers was performed on a sediment core spanning the last 34,800 years on the upper slope southeast of Brazil to verify the signatures of climatic variations in sea surface temperature (SST), marine productivity, and the flux of terrigenous material in this region. This evaluation is based on marine and terrigenous proxies including alkenones, chlorins, aliphatic hydrocarbons, n-alcohols, and fatty acids. This first report of organic biomarker data for this region confirms a correlation between SST, changes in terrigenous organic matter flow into the ocean, and marine productivity over the last 34.8 ka as a response to the displacement of the Brazil Current. Conditions prevailing during marine isotopic stage (MIS) 3 may be considered intermediate between the last glacial maximum (LGM) and the Late Holocene. For MIS 2, a period of low relative sea level, it was verified that the lowest SSTs were associated with the LGM and higher marine productivity. SST increased by up to 4.4 °C between the LGM and the Holocene. This reveals synchronicity between SST on the southeastern Brazilian upper slope and the North Atlantic Ocean SST records reported in earlier studies.

  15. Organic biomarker records spanning the last 34,800 years from the southeastern Brazilian upper slope: links between sea surface temperature, displacement of the Brazil Current, and marine productivity

    Science.gov (United States)

    Lourenço, Rafael André; de Mahiques, Michel Michaelovitch; Wainer, Ilana Elazari Klein Coaracy; Rosell-Melé, Antoni; Bícego, Márcia Caruso

    2016-06-01

    Collective assessment of marine and terrigenous organic biomarkers was performed on a sediment core spanning the last 34,800 years on the upper slope southeast of Brazil to verify the signatures of climatic variations in sea surface temperature (SST), marine productivity, and the flux of terrigenous material in this region. This evaluation is based on marine and terrigenous proxies including alkenones, chlorins, aliphatic hydrocarbons, n-alcohols, and fatty acids. This first report of organic biomarker data for this region confirms a correlation between SST, changes in terrigenous organic matter flow into the ocean, and marine productivity over the last 34.8 ka as a response to the displacement of the Brazil Current. Conditions prevailing during marine isotopic stage (MIS) 3 may be considered intermediate between the last glacial maximum (LGM) and the Late Holocene. For MIS 2, a period of low relative sea level, it was verified that the lowest SSTs were associated with the LGM and higher marine productivity. SST increased by up to 4.4 °C between the LGM and the Holocene. This reveals synchronicity between SST on the southeastern Brazilian upper slope and the North Atlantic Ocean SST records reported in earlier studies.

  16. The Electrical Breakdown of Thin Dielectric Elastomers

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed;

    2014-01-01

    Dielectric elastomers are being developed for use in actuators, sensors and generators to be used in various applications, such as artificial eye lids, pressure sensors and human motion energy generators. In order to obtain maximum efficiency, the devices are operated at high electrical fields....... This increases the likelihood for electrical breakdown significantly. Hence, for many applications the performance of the dielectric elastomers is limited by this risk of failure, which is triggered by several factors. Amongst others thermal effects may strongly influence the electrical breakdown strength....... In this study, we model the electrothermal breakdown in thin PDMS based dielectric elastomers in order to evaluate the thermal mechanisms behind the electrical failures. The objective is to predict the operation range of PDMS based dielectric elastomers with respect to the temperature at given electric field...

  17. Spectrometers for RF breakdown studies for CLIC

    Science.gov (United States)

    Jacewicz, M.; Ziemann, V.; Ekelöf, T.; Dubrovskiy, A.; Ruber, R.

    2016-08-01

    An e+e- collider of several TeV energy will be needed for the precision studies of any new physics discovered at the LHC collider at CERN. One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC is the electrical breakdown at very high electrical field. The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of the emitted breakdown currents during two-beam acceleration experiments. It gives a unique possibility to measure the energy of electrons and ions in combination with the arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands. The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN. Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the

  18. The work breakdown structure in software project management

    Science.gov (United States)

    Tausworthe, R. C.

    1980-01-01

    A work breakdown structure (WBS) is defined as an enumeration of all work activities in hierarchic refinement of detail which organizes work to be done into short manageable tasks with quantifiable inputs, outputs, schedules, and assigned responsibilities. Some of the characteristics and benefits of the WBS are reviewed, and ways in which these can be developed and applied in software implementation projects are discussed. Although the material is oriented principally toward new-software production tasks, many of the concepts are applicable to continuing maintenance and operations tasks.

  19. The Resistance of Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2008-01-01

    Full Text Available The conditions under which breakdown of composite liquid - solid insulation can be occurred, e.g., in transformer,play an important role in designing of such insulation. The initial state of breakdown development is explained on the basisof bubble theory and formation of a plasma channel between the electrodes. The electrical resistance of plasma channel iscalculated using several theories and its changes from a few ohms to a few hundred milliohms due to Joule heating caused byhigh arc current which flows through the plasma. The dynamics of the arc current depends on the parameters of outer circuitand is represented by RLC circuit.

  20. [Biomarkers in Alzheimer's disease].

    Science.gov (United States)

    García-Ribas, G; López-Sendón Moreno, J L; García-Caldentey, J

    2014-04-01

    The new diagnostic criteria for Alzheimer's disease (AD) include brain imaging and cerebrospinal fluid (CSF) biomarkers, with the aim of increasing the certainty of whether a patient has an ongoing AD neuropathologic process or not. Three CSF biomarkers, Aß42, total tau, and phosphorylated tau, reflect the core pathological features of AD. It is already known that these pathological processes of AD starts decades before the first symptoms, so these biomarkers may provide means of early disease detection. At least three stages of AD could be identified: preclinical AD, mild cognitive impairment due to AD, and dementia due to AD. In this review, we aim to summarize the CSF biomarker data available for each of these stages. We also review the actual research on blood-based biomarkers. Recent studies on healthy elderly subjects and on carriers of dominantly inherited AD mutations have also found biomarker changes that allow separate groups in these preclinical stages. These studies may aid for segregate populations in clinical trials and objectively evaluate if there are changes over the pathological processes of AD. Limits to widespread use of CSF biomarkers, apart from the invasive nature of the process itself, is the higher coefficient of variation for the analyses between centres. It requires strict pre-analytical and analytical procedures that may make feasible multi-centre studies and global cut-off points for the different stages of AD.

  1. Biomarkers in Severe Asthma.

    Science.gov (United States)

    Wan, Xiao Chloe; Woodruff, Prescott G

    2016-08-01

    Biomarkers have been critical for studies of disease pathogenesis and the development of new therapies in severe asthma. In particular, biomarkers of type 2 inflammation have proven valuable for endotyping and targeting new biological agents. Because of these successes in understanding and marking type 2 inflammation, lack of knowledge regarding non-type 2 inflammatory mechanisms in asthma will soon be the major obstacle to the development of new treatments and management strategies in severe asthma. Biomarkers can play a role in these investigations as well by providing insight into the underlying biology in human studies of patients with severe asthma. PMID:27401625

  2. Validation of New Cancer Biomarkers

    DEFF Research Database (Denmark)

    Duffy, Michael J; Sturgeon, Catherine M; Söletormos, Georg;

    2015-01-01

    in advancing a newly discovered cancer candidate biomarker from pilot studies to clinical application. Four main steps are necessary for a biomarker to reach the clinic: analytical validation of the biomarker assay, clinical validation of the biomarker test, demonstration of clinical value from performance...... of the biomarker test, and regulatory approval. In addition to these 4 steps, all biomarker studies should be reported in a detailed and transparent manner, using previously published checklists and guidelines. Finally, all biomarker studies relating to demonstration of clinical value should be registered before...

  3. Numerical Borehole Breakdown Investigations using XFEM

    Science.gov (United States)

    Beckhuis, Sven; Leonhart, Dirk; Meschke, Günther

    2016-04-01

    During pressurization of a wellbore a typical downhole pressure record shows the following regimes: first the applied wellbore pressure balances the reservoir pressure, then after the compressive circumferential hole stresses are overcome, tensile stresses are induced on the inside surface of the hole. When the magnitude of these stresses reach the tensile failure stress of the surrounding rock medium, a fracture is initiated and propagates into the reservoir. [1] In standard theories this pressure, the so called breakdown pressure, is the peak pressure in the down-hole pressure record. However experimental investigations [2] show that the breakdown did not occur even if a fracture was initiated at the borehole wall. Drilling muds had the tendency to seal and stabilize fractures and prevent fracture propagation. Also fracture mechanics analysis of breakdown process in mini-frac or leak off tests [3] show that the breakdown pressure could be either equal or larger than the fracture initiation pressure. In order to gain a deeper understanding of the breakdown process in reservoir rock, numerical investigations using the extended finite element method (XFEM) for hydraulic fracturing of porous materials [4] are discussed. The reservoir rock is assumed to be pre-fractured. During pressurization of the borehole, the injection pressure, the pressure distribution and the position of the highest flux along the fracture for different fracturing fluid viscosities are recorded and the influence of the aforementioned values on the stability of fracture propagation is discussed. [1] YEW, C. H. (1997), "Mechanics of Hydraulic Fracturing", Gulf Publishing Company [2] MORITA, N.; BLACK, A. D.; FUH, G.-F. (1996), "Borehole Breakdown Pressure with Drilling Fluids". International Journal of Rock Mechanics and Mining Sciences 33, pp. 39-51 [3] DETOURNAY, E.; CARBONELL, R. (1996), "Fracture Mechanics Analysis of the Breakdown Process in Minifrac or Leakoff Test", Society of Petroleum

  4. Biomarker time out.

    Science.gov (United States)

    Petzold, Axel; Bowser, Robert; Calabresi, Paolo; Zetterberg, Henrik; Uitdehaag, Bernard M J

    2014-10-01

    The advancement of knowledge relies on scientific investigations. The timing between asking a question and data collection defines if a study is prospective or retrospective. Prospective studies look forward from a point in time, are less prone to bias and are considered superior to retrospective studies. This conceptual framework conflicts with the nature of biomarker research. New candidate biomarkers are discovered in a retrospective manner. There are neither resources nor time for prospective testing in all cases. Relevant sources for bias are not covered. Ethical questions arise through the time penalty of an overly dogmatic concept. The timing of sample collection can be separated from testing biomarkers. Therefore the moment of formulating a hypothesis may be after sample collection was completed. A conceptual framework permissive to asking research questions without the obligation to bow to the human concept of calendar time would simplify biomarker research, but will require new safeguards against bias.

  5. Biomarkers in Airway Diseases

    Directory of Open Access Journals (Sweden)

    Janice M Leung

    2013-01-01

    Full Text Available The inherent limitations of spirometry and clinical history have prompted clinicians and scientists to search for surrogate markers of airway diseases. Although few biomarkers have been widely accepted into the clinical armamentarium, the authors explore three sources of biomarkers that have shown promise as indicators of disease severity and treatment response. In asthma, exhaled nitric oxide measurements can predict steroid responsiveness and sputum eosinophil counts have been used to titrate anti-inflammatory therapies. In chronic obstructive pulmonary disease, inflammatory plasma biomarkers, such as fibrinogen, club cell secretory protein-16 and surfactant protein D, can denote greater severity and predict the risk of exacerbations. While the multitude of disease phenotypes in respiratory medicine make biomarker development especially challenging, these three may soon play key roles in the diagnosis and management of airway diseases.

  6. Breakdown of C3 after complement activation. Identification of a new fragment C3g, using monoclonal antibodies

    OpenAIRE

    1982-01-01

    The physiological breakdown of C3 has been studied using monoclonal anti-C3 antibodies, and it has been found that the later stages of this process--the breakdown of C3bi--is more complex than had previously been recognized. C3bi is the reaction product produced from C3b by the action of factor I which, in the presence of factor H, produces a double cleavage in the alpha chain of C3b. It is here reported that, both on cells and in the fluid phase, the breakdown of C3bi in serum gives rise to ...

  7. Electrical breakdown of carbon nanotube devices and the predictability of breakdown position

    Directory of Open Access Journals (Sweden)

    Gopal Krishna Goswami

    2012-06-01

    Full Text Available We have investigated electrical transport properties of long (>10 μm multiwalled carbon nanotubes (NTs by dividing individuals into several segments of identical length. Each segment has different resistance because of the random distribution of defect density in an NT and is corroborated by Raman studies. Higher is the resistance, lower is the current required to break the segments indicating that breakdown occurs at the highly resistive segment/site and not necessarily at the middle. This is consistent with the one-dimensional thermal transport model. We have demonstrated the healing of defects by annealing at moderate temperatures or by current annealing. To strengthen our mechanism, we have carried out electrical breakdown of nitrogen doped NTs (NNTs with diameter variation from one end to the other. It reveals that the electrical breakdown occurs selectively at the narrower diameter region. Overall, we believe that our results will help to predict the breakdown position of both semiconducting and metallic NTs.

  8. Translation of neurological biomarkers to clinically relevant platforms.

    Science.gov (United States)

    Hayes, Ronald L; Robinson, Gillian; Muller, Uwe; Wang, Kevin K W

    2009-01-01

    Like proteomics more generally, neuroproteomics has recently been linked to the discovery of biochemical markers of central nervous system (CNS) injury and disease. Although neuroproteomics has enjoyed considerable success in discovery of candidate biomarkers, there are a number of challenges facing investigators interested in developing clinically useful platforms to assess biomarkers for damage to the CNS. These challenges include intrinsic physiological complications such as the blood-brain barrier. Effective translation of biomarkers to clinical practice also requires development of entirely novel pathways and product development strategies. Drawing from lessons learned from applications of biomarkers to traumatic brain injury, this study outlines major elements of such a pathway. As with other indications, biomarkers can have three major areas of application: (1) drug development; (2) diagnosis and prognosis; (3) patient management. Translation of CNS biomarkers to practical clinical platforms raises a number of integrated elements. Biomarker discovery and initial selection needs to be integrated at the earliest stages with components that will allow systematic prioritization and triage of biomarker candidates. A number of important criteria need to be considered in selecting clinical biomarker candidates. Development of proof of concept assays and their optimization and validation represent an often overlooked feature of biomarker translational research. Initial assay optimization should confirm that assays can detect biomarkers in relevant clinical samples. Since access to human clinical samples is critical to identification of biomarkers relevant to injury and disease as well as for assay development, design of human clinical validation studies is an important component of translational biomarker research platforms. Although these clinical studies share much in common with clinical trials for assessment of drug therapeutic efficacy, there are a number of

  9. Cholecystokinin receptors: disparity between phosphoinositide breakdown and amylase releasing activity of CCK analogues in pancreas

    International Nuclear Information System (INIS)

    Cholecystokinin (CCK) peptides are a family of hormones which also occur in brain. In pancreas CCK stimulates the release of amylase, a process that is dependent on the mobilization of intracellular Ca2+. Recent evidence suggests that inositol 1,4,5-trisphosphate, the breakdown product of phosphatidylinositol 4,5-bisphosphate, is responsible for the rise in intracellular Ca2+. Their laboratory has developed assays to study synthetic CCK analogues using radioligand binding, PI breakdown and amylase release. They have shown that there are good correlations among these three assay systems for the carboxy terminal fragments of CCK8. Recently, they have discovered synthetic analogues of CCK4 that are full agonists in amylase release but are ineffective in causing PI breakdown. In particular, A-61576, Boc-5-amino-2-indolemethylene-pent-2-ene-1-oyl-Leu-Asp-Phe-NH2, is a full agonist in the amylase releasing assay, but is devoid of PI stimulating activity. A-61576 completely reverses the stimulation of PI response induced by CCK8, indicative of an antagonist. Since a mechanism other than the PI breakdown is responsible for amylase release by A-61576, they suggest that separate receptors are responsible for PI breakdown and amylase release

  10. High-voltage breakdown studies on Si microstrip detectors

    CERN Document Server

    Albergo, S; Azzi, P; Babucci, E; Bacchetta, N; Bader, A J; Bagliesi, G; Basti, A; Biggeri, U; Bilei, G M; Bisello, D; Boemi, D; Bosi, F; Borrello, L; Bozzi, C; Braibant, S; Breuker, Horst; Bruzzi, Mara; Buffini, A; Busoni, S; Calefato, G; Candelori, A; Caner, A; Castaldi, R; Castro, A; Catacchini, E; Checcucci, B; Ciampolini, P; Civinini, C; Creanza, D; D'Alessandro, R; Da Rold, M; Demaria, N; De Palma, M; Dell'Orso, R; Marina, R D; Dutta, S; Eklund, C; Peisert, Anna; Feld, L; Fiore, L; Focardi, E; French, M; Freudenreich, Klaus; Fürtjes, A; Giassi, A; Giorgi, M A; Giraldo, A; Glessing, B; Gu, W H; Hall, G; Hammarström, R; Hebbeker, T; Hrubec, Josef; Muhtinen, M; Kaminski, A; Karimäki, V; Saint-Koenig, M; Krammer, Manfred; Lariccia, P; Lenzi, M; Loreti, M; Lübelsmeyer, K; Lustermann, W; Mättig, P; Maggi, G; Mannelli, M; Mantovani, G C; Marchioro, A; Mariotti, C; Martignon, G; McEvoy, B; Meschini, M; Messineo, A; My, S; Paccagnella, A; Palla, Fabrizio; Pandoulas, D; Papi, A; Parrini, G; Passeri, D; Pieri, M; Piperov, S; Potenza, R; Radicci, V; Raffaelli, F; Raymond, M; Santocchia, A; Schmitt, B; Selvaggi, G; Servoli, L; Sguazzoni, G; Siedling, R; Silvestris, L; Skog, K; Starodumov, Andrei; Stavitski, I; Stefanini, G; Tempesta, P; Tonelli, G; Tricomi, A; Tuuva, T; Vannini, C; Verdini, P G; Viertel, Gert M; Zie, Z; Li Ya Hong; Watts, S; Wittmer, B

    1999-01-01

    The breakdown performance of CMS barrel module prototype detectors and test devices with single and multi-guard structures were studied before and after neutron irradiation up to 2-10/sup 14/ 1 MeV equivalent neutrons. Before irradiation avalanche breakdown occurred at the guard ring implant edges. We measured 100-300 V higher breakdown voltage values for the devices with multi-guard than for devices with single-guard ring, After irradiation and type inversion the breakdown was smoother than before irradiation and the breakdown voltage value increased to 500-600 V for most of the devices. (9 refs).

  11. Breakdown and partial discharges in magnetic liquids.

    Science.gov (United States)

    Herchl, F; Marton, K; Tomčo, L; Kopčanský, P; Timko, M; Koneracká, M; Kolcunová, I

    2008-05-21

    The dielectric properties (permittivity, loss factor, dielectric breakdown strength) of magnetic liquids were investigated. The magnetic liquids were composed of magnetite particles coated with oleic acid as surfactant and dispersed in transformer oil. To determine their dielectric properties they were subjected to a uniform magnetic field at high alternating electric fields up to 14 MV m(-1). Nearly constant permittivity of magnetic liquid with particle volume concentration Φ = 0.0019 as a function of electric field was observed. Magnetic liquids with concentrations Φ = 0.019 and 0.032 showed significant changes of permittivity and loss factor dependent on electric and magnetic fields. The best concentration of magnetic fluid was found at which partial current impulse magnitudes were the lowest. The breakdown strength distribution of the magnetic liquid with Φ = 0.0025 was fitted with the Duxbury-Leath, Weibull and Gauss distribution functions. PMID:21694240

  12. Mass spectrometry for biomarker development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chaochao; Liu, Tao; Baker, Erin Shammel; Rodland, Karin D.; Smith, Richard D.

    2015-06-19

    Biomarkers potentially play a crucial role in early disease diagnosis, prognosis and targeted therapy. In the past decade, mass spectrometry based proteomics has become increasingly important in biomarker development due to large advances in technology and associated methods. This chapter mainly focuses on the application of broad (e.g. shotgun) proteomics in biomarker discovery and the utility of targeted proteomics in biomarker verification and validation. A range of mass spectrometry methodologies are discussed emphasizing their efficacy in the different stages in biomarker development, with a particular emphasis on blood biomarker development.

  13. Cooperation Breakdowns under Incomplete Property Rights

    OpenAIRE

    Jean-Pierre Tranchant

    2005-01-01

    In order to analyze conflict and cooperation between a State and a non ruling group in a general equilibrium, I unite pure rent-seeking models and economic models of conflict under an assumption of incomplete property rights. I show that a unique and globally stable Nash equilibrium exists in this game. Cooperation breakdowns appear to be twofold: generalized conflict driven by a collapse of the State and one- sided rebellion due to the coexistence between a strong State and a weak minority. ...

  14. Next-Generation Biomarkers of Health.

    Science.gov (United States)

    van Ommen, Ben; Wopereis, Suzan

    2016-01-01

    Current biomarkers used in health care and in nutrition and health research are based on quantifying disease onset and its progress. Yet, both health care and nutrition should focus on maintaining optimal health, where the related biology is essentially differing from biomedical science. Health is characterized by the ability to continuously adapt in varying circumstances where multiple mechanisms of systems flexibility are involved. A new generation of biomarkers is needed that quantifies all aspects of systems flexibility, opening the door to real lifestyle-related health optimization, self-empowerment, and related products and services.

  15. Kinetic Simulations of Dense Plasma Focus Breakdown

    Science.gov (United States)

    Schmidt, A.; Higginson, D. P.; Jiang, S.; Link, A.; Povilus, A.; Sears, J.; Bennett, N.; Rose, D. V.; Welch, D. R.

    2015-11-01

    A dense plasma focus (DPF) device is a type of plasma gun that drives current through a set of coaxial electrodes to assemble gas inside the device and then implode that gas on axis to form a Z-pinch. This implosion drives hydrodynamic and kinetic instabilities that generate strong electric fields, which produces a short intense pulse of x-rays, high-energy (>100 keV) electrons and ions, and (in deuterium gas) neutrons. A strong factor in pinch performance is the initial breakdown and ionization of the gas along the insulator surface separating the two electrodes. The smoothness and isotropy of this ionized sheath are imprinted on the current sheath that travels along the electrodes, thus making it an important portion of the DPF to both understand and optimize. Here we use kinetic simulations in the Particle-in-cell code LSP to model the breakdown. Simulations are initiated with neutral gas and the breakdown modeled self-consistently as driven by a charged capacitor system. We also investigate novel geometries for the insulator and electrodes to attempt to control the electric field profile. The initial ionization fraction of gas is explored computationally to gauge possible advantages of pre-ionization which could be created experimentally via lasers or a glow-discharge. Prepared by LLNL under Contract DE-AC52-07NA27344.

  16. Electromagnetic analysis of breakdown conditions in JET

    Energy Technology Data Exchange (ETDEWEB)

    Maviglia, F., E-mail: francesco.maviglia@unirc.it [Associazione EURATOM-ENEA-CREATE, Univ. di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Albanese, R. [Associazione EURATOM-ENEA-CREATE, Univ. di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Alonso, A. [Asociacion EURATOM-CIEMAT para Fusion, CIEMAT, Madrid (Spain); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom)

    2011-10-15

    This paper presents the breakdown studies carried out in the framework of JET Enhancement Projects for Plasma Control Upgrade (PCU) and Enhanced Radial Field Amplifier (ERFA), to obtain plasma formation with different sets of coil turns in the radial field circuit. The electromagnetic conditions to reach the plasma breakdown in the JET machine are strongly dependent on the properties of JET iron core and the effects of the eddy currents driven by the transient electric field on the present passive structures. The study has been carried out by using a linearized dynamic model of JET provided by 2D axisymmetric finite element code CREATE-L [R. Albanese, et al., Nucl. Fusion 38 (1998) 723-738]. The dynamic simulations have been compared with the experimental data. A new fast visible camera has been installed and has been used for the first time at JET for studies of plasma breakdown. The images show, coherently with the model, that the avalanche evolves dynamically towards a region where the stray field is perpendicular to the first wall.

  17. Comparative Studies of High-Gradient Rf and Dc Breakdowns

    CERN Document Server

    Kovermann, Jan Wilhelm; Wuensch, Walter

    2010-01-01

    The CLIC project is based on normal-conducting high-gradient accelerating structures with an average accelerating gradient of 100 MV/m. The maximum achievable gradient in these structures is limited by the breakdown phenomenon. The physics of breakdowns is not yet fully understood quantitatively. A full knowledge could have strong impact on the design, material choice and construction of rf structures. Therefore, understanding breakdowns has great importance to reaching a gradient of 100MV/m with an acceptable breakdown probability. This thesis addresses the physics underlying the breakdown effect, focusing on a comparison of breakdowns in rf structures and in a dc spark setup. The dc system is simpler, easier to benchmark against simulations, with a faster turnaround time, but the relationship to rf breakdown must be established. To do so, an experimental approach based on optical diagnostics and electrical measurements methods was made. Following an introduction into the CLIC project, a general theoretical ...

  18. Biomarkers of the Dementia

    Directory of Open Access Journals (Sweden)

    Mikio Shoji

    2011-01-01

    Full Text Available Recent advances in biomarker studies on dementia are summarized here. CSF Aβ40, Aβ42, total tau, and phosphorylated tau are the most sensitive biomarkers for diagnosis of Alzheimer's disease (AD and prediction of onset of AD from mild cognitive impairment (MCI. Based on this progress, new diagnostic criteria for AD, MCI, and preclinical AD were proposed by National Institute of Aging (NIA and Alzheimer's Association in August 2010. In these new criteria, progress in biomarker identification and amyloid imaging studies in the past 10 years have added critical information. Huge contributions of basic and clinical studies have established clinical evidence supporting these markers. Based on this progress, essential therapy for cure of AD is urgently expected.

  19. DETECTION OF CANCER BIOMARKERS WITH NANOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2013-01-01

    Full Text Available Early detection of cancer biomarkers with high precision is critically important for cancer therapy. A variety of sensors based on different nanostructured materials have attracted intensive research interest due to their potential for highly sensitive and selective detection of cancer biomarkers. This review covers the use of a variety of nanostructured materials, including carbon nanotubes, silicon nanowires, gold nanoparticles and quantum dots, in the fabrication of sensors. Emphases are placed on how the detection systems work and what detection limits can be achieved. Some assays described in this review outperform established methods for cancer biomarker detection. It is highly promising that these sensors would soon move into commercial-scale production and find routine use in hospitals.

  20. Incorporating Biomarkers in Studies of Chemoprevention.

    Science.gov (United States)

    Fabian, Carol J; Kimler, Bruce F

    2016-01-01

    Despite Food and Drug Administration approval of tamoxifen and raloxifene for breast cancer risk reduction and endorsement by multiple agencies, uptake of these drugs for primary prevention in the United States is only 4% for risk eligible women likely to benefit from their use. Side effects coupled with incomplete efficacy and lack of a survival advantage are the likely reasons. This disappointing uptake, after the considerable effort and expense of large Phase III cancer incidence trials required for approval, suggests that a new paradigm is required. Current prevention research is focused on (1) refining risk prediction, (2) exploring behavioral and natural product interventions, and (3) utilizing novel translational trial designs for efficacy. Risk biomarkers will play a central role in refining risk estimates from traditional models and selecting cohorts for prevention trials. Modifiable risk markers called surrogate endpoint or response biomarkers will continue to be used in Phase I and II prevention trials to determine optimal dose or exposure and likely effectiveness from an intervention. The majority of Phase II trials will continue to assess benign breast tissue for response and mechanism of action biomarkers. Co-trials are those in which human and animal cohorts receive the same effective dose and the same tissue biomarkers are assessed for modulation due to the intervention, but then additional animals are allowed to progress to cancer development. These collaborations linking biomarker modulation and cancer prevention may obviate the need for cancer incidence trials for non-prescription interventions. PMID:26987531

  1. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A

  2. Biomarkers for systemic lupus erythematosus.

    Science.gov (United States)

    Ahearn, Joseph M; Liu, Chau-Ching; Kao, Amy H; Manzi, Susan

    2012-04-01

    The urgent need for lupus biomarkers was demonstrated in September 2011 during a Workshop sponsored by the Food and Drug Administration: Potential Biomarkers Predictive of Disease Flare. After 2 days of discussion and more than 2 dozen presentations from thought leaders in both industry and academia, it became apparent that highly sought biomarkers to predict lupus flare have not yet been identified. Even short of the elusive biomarker of flare, few biomarkers for systemic lupus erythematosus (SLE) diagnosis, monitoring, and stratification have been validated and employed for making clinical decisions. This lack of reliable, specific biomarkers for SLE hampers proper clinical management of patients with SLE and impedes development of new lupus therapeutics. As such, the intensity of investigation to identify lupus biomarkers is climbing a steep trajectory, lending cautious optimism that a validated panel of biomarkers for lupus diagnosis, monitoring, stratification, and prediction of flare may soon be in hand.

  3. Biomarkers in Barrett's esophagus.

    Science.gov (United States)

    Reid, Brian J; Blount, Patricia L; Rabinovitch, Peter S

    2003-04-01

    This article provides a framework for clinicians who are attempting the difficult task of interpreting the Barrett's biomarker literature with the goal of improving care for their patients. Although many articles. including more that 60 proposed biomarkers, have been published on this subject, only a few describe phase 3 and 4 studies that are of interest to the clinical gastroenterologist (Table 1). For year, dysplasia grade has been the sole means of risk stratification for patients with BE, and it likely will continue to be used in the foreseeable future. The current authors believe that dysplasia classification can be valuable using the team management approach and quality controls described previously. Significant problems, however, have emerged in phase 2 through 4 studies of dysplasia that make it imperative for the Barrett's field to incorporate additional biomarkers as they are validated. These problems include poor reproducibility of dysplasia interpretations, poor predictive value for negative, indefinite, and low-grade dysplasia, and inconsistent results for HGD in different centers, all of which makes it virtually impossible to develop national guidelines for surveillance. Some studies have even suggested that endoscopic biopsy surveillance using dysplasia may not be worthwhile. Currently, flow cytometric tetraploidy and aneuploidy have progressed furthest in biomarker validation (see Table 1). With proper handling, endoscopic biopsy specimens can be shipped to reference laboratories that have the instruments, computer analytic methods, and expertise to reproducibly detect tetraploidy and aneuploidy. The results of phase 4 studies indicate that flow cytometry appears to be useful in detecting a subset of patients who do not have HGD and yet have an increased risk of progression to cancer that cannot be identified by dysplasia grade. For many reasons, the authors anticipate that the number of validated biomarkers will increase substantially in the

  4. Role of Lipid Peroxidation Products, Plasma Total Antioxidant Status, and Cu-, Zn-Superoxide Dismutase Activity as Biomarkers of Oxidative Stress in Elderly Prediabetics

    Directory of Open Access Journals (Sweden)

    Sylwia Dzięgielewska-Gęsiak

    2014-01-01

    Full Text Available The relationship between hyperglycemia and oxidative stress in diabetes is well known, but the influence of metabolic disturbances recognized as prediabetes, in elderly patients especially, awaits for an explanation. Methods. 52 elderly persons (65 years old and older with no acute or severe chronic disorders were assessed: waist circumference (WC, body mass index (BMI, percentage of body fat (FAT, and arterial blood pressure. During an oral glucose tolerance test (OGTT fasting (0′ and 120-minute (120′ glycemia and insulinemia were determined, and type 2 diabetics (n=6 were excluded. Subjects were tested for glycated hemoglobin HbA1c, plasma lipids, total antioxidant status (TAS, thiobarbituric acid-reacting substances (TBARS, and activity of erythrocyte superoxide dismutase (SOD-1. According to OGTT results, patients were classified as normoglycemics, (NGT, n=18 and prediabetics, (PRE, n=28. Results. Both groups did not differ with their lipids, FAT, and TBARS. PRE group had higher WC (P<0.002 and BMI (P<0.002. Lower SOD-1 activity (P<0.04 and TAS status (P<0.04 were found in PRE versus NGT group. Significance. In elderly prediabetics, SOD-1 and TAS seem to reflect the first symptoms of oxidative stress, while TBARS are later biomarkers of oxidative stress.

  5. Proteomic Biomarkers of Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Natacha Diaz-Prieto

    2008-01-01

    Full Text Available Biomarkers provide a powerful approach to understanding the spectrum of cardiovascular diseases. They have application in screening, diagnostic, prognostication, prediction of recurrences and monitoring of therapy. The “omics” tool are becoming very useful in the development of new biomarkers in cardiovascular diseases. Among them, proteomics is especially fitted to look for new proteins in health and disease and is playing a significant role in the development of new diagnostic tools in cardiovascular diagnosis and prognosis. This review provides an overview of progress in applying proteomics to atherosclerosis. First, we describe novel proteins identified analysing atherosclerotic plaques directly. Careful analysis of proteins within the atherosclerotic vascular tissue can provide a repertoire of proteins involved in vascular remodelling and atherogenesis. Second, we discuss recent data concerning proteins secreted by atherosclerotic plaques. The definition of the atheroma plaque secretome resides in that proteins secreted by arteries can be very good candidates of novel biomarkers. Finally we describe proteins that have been differentially expressed (versus controls by individual cells which constitute atheroma plaques (endothelial cells, vascular smooth muscle cells, macrophages and foam cells as well as by circulating cells (monocytes, platelets or novel biomarkers present in plasma.

  6. Proteomic Biomarkers of Atherosclerosis.

    Science.gov (United States)

    Vivanco, F; Padial, L R; Darde, V M; de la Cuesta, F; Alvarez-Llamas, G; Diaz-Prieto, Natacha; Barderas, M G

    2008-01-01

    SUMMARY: Biomarkers provide a powerful approach to understanding the spectrum of cardiovascular diseases. They have application in screening, diagnostic, prognostication, prediction of recurrences and monitoring of therapy. The "omics" tool are becoming very useful in the development of new biomarkers in cardiovascular diseases. Among them, proteomics is especially fitted to look for new proteins in health and disease and is playing a significant role in the development of new diagnostic tools in cardiovascular diagnosis and prognosis. This review provides an overview of progress in applying proteomics to atherosclerosis. First, we describe novel proteins identified analysing atherosclerotic plaques directly. Careful analysis of proteins within the atherosclerotic vascular tissue can provide a repertoire of proteins involved in vascular remodelling and atherogenesis. Second, we discuss recent data concerning proteins secreted by atherosclerotic plaques. The definition of the atheroma plaque secretome resides in that proteins secreted by arteries can be very good candidates of novel biomarkers. Finally we describe proteins that have been differentially expressed (versus controls) by individual cells which constitute atheroma plaques (endothelial cells, vascular smooth muscle cells, macrophages and foam cells) as well as by circulating cells (monocytes, platelets) or novel biomarkers present in plasma. PMID:19578499

  7. Emerging Biomarkers in Glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, Mairéad G.; Sahebjam, Solmaz; Mason, Warren P., E-mail: warren.mason@uhn.ca [Pencer Brain Tumor Centre, Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada)

    2013-08-22

    Glioblastoma, the most common primary brain tumor, has few available therapies providing significant improvement in survival. Molecular signatures associated with tumor aggressiveness as well as with disease progression and their relation to differences in signaling pathways implicated in gliomagenesis have recently been described. A number of biomarkers which have potential in diagnosis, prognosis and prediction of response to therapy have been identified and along with imaging modalities could contribute to the clinical management of GBM. Molecular biomarkers including O(6)-methlyguanine-DNA-methyltransferase (MGMT) promoter and deoxyribonucleic acid (DNA) methylation, loss of heterozygosity (LOH) of chromosomes 1p and 19q, loss of heterozygosity 10q, isocitrate dehydrogenase (IDH) mutations, epidermal growth factor receptor (EGFR), epidermal growth factor, latrophilin, and 7 transmembrane domain-containing protein 1 on chromosome 1 (ELTD1), vascular endothelial growth factor (VEGF), tumor suppressor protein p53, phosphatase and tensin homolog (PTEN), p16INK4a gene, cytochrome c oxidase (CcO), phospholipid metabolites, telomerase messenger expression (hTERT messenger ribonucleic acid [mRNA]), microRNAs (miRNAs), cancer stem cell markers and imaging modalities as potential biomarkers are discussed. Inclusion of emerging biomarkers in prospective clinical trials is warranted in an effort for more effective personalized therapy in the future.

  8. HEAD INJURY ASSESSMENT IN JUVENILE CHINOOK USING THE ALPHA II-SPECTRIN BIOMARKER: EFFECTS OF PRESSURE CHANGES AND PASSAGE THROUGH A REMOVABLE SPILLWAY WEIR

    Energy Technology Data Exchange (ETDEWEB)

    Jonason, C.; Miracle, A.

    2009-01-01

    The cytoskeletal protein alpha II-spectrin has specifi c neurodegenerative mechanisms that allow the necrotic (injury-induced) and apoptotic (non-injury-induced) pathways of proteolysis to be differentiated in an immunoblot. Consequently, αII-spectrin breakdown products (SBDPs) are potential biomarkers for diagnosing traumatic brain injury (TBI). The purpose of the following investigation, consisting of two studies, was to evaluate the utility of the spectrin biomarker in diagnosing TBI in fi sh that travel through hydroelectric dams in the Columbia and Snake Rivers. The fi rst study used hyperbaric pressure chambers to simulate the pressure changes that affect fi sh during passage through a Federal Columbia River Power System (FCRPS) Kaplan turbine. The second study tested the effect of a removable spillway weir (RSW) on the passage of juvenile chinook (Oncorhynchus tshawytscha). This study was conducted in tandem with a balloon-tag study by the U.S. Army Corps of Engineers. Brain samples from fi sh were collected and analyzed using an immunoblot for SBDPs, and imaging software was used to quantify the protein band density and determine the ratio of cleaved protein to total protein. The biomarker analyses found higher SBDP expression levels in fi sh that were exposed to lower pressure nadirs and fi sh that passed through the RSW at a deep orientation. In general, the incidence of injuries observed after treatment positively correlated with expression levels, suggesting that the biomarker method of analysis is comparable to traditional methods of injury assessment. It was also found that, for some treatments, the 110 kDa spectrin fragment (SBDP 110) correlated more strongly with necrotic head injury incidence and mortality rates than did the total cleaved protein or the 120 kDa fragment. These studies will be informative in future decisions regarding the design of turbines and fi sh passage structures in hydroelectric dams and will hopefully contribute to the

  9. 2-Furoylglycine as a Candidate Biomarker of Coffee Consumption.

    Science.gov (United States)

    Heinzmann, Silke S; Holmes, Elaine; Kochhar, Sunil; Nicholson, Jeremy K; Schmitt-Kopplin, Philippe

    2015-09-30

    Specific and sensitive food biomarkers are necessary to support dietary intake assessment and link nutritional habits to potential impact on human health. A multistep nutritional intervention study was conducted to suggest novel biomarkers for coffee consumption. (1)H NMR metabolic profiling combined with multivariate data analysis resolved 2-furoylglycine (2-FG) as a novel putative biomarker for coffee consumption. We relatively quantified 2-FG in the urine of coffee drinkers and investigated its origin, metabolism, and excretion kinetics. When searching for its potential precursors, we found different furan derivatives in coffee products, which are known to get metabolized to 2-FG. Maximal urinary excretion of 2-FG occurred 2 h after consumption (p = 0.0002) and returned to baseline after 24 h (p = 0.74). The biomarker was not excreted after consumption of coffee substitutes such as tea and chicory coffee and might therefore be a promising acute biomarker for the detection of coffee consumption in human urine.

  10. 2-Furoylglycine as a Candidate Biomarker of Coffee Consumption.

    Science.gov (United States)

    Heinzmann, Silke S; Holmes, Elaine; Kochhar, Sunil; Nicholson, Jeremy K; Schmitt-Kopplin, Philippe

    2015-09-30

    Specific and sensitive food biomarkers are necessary to support dietary intake assessment and link nutritional habits to potential impact on human health. A multistep nutritional intervention study was conducted to suggest novel biomarkers for coffee consumption. (1)H NMR metabolic profiling combined with multivariate data analysis resolved 2-furoylglycine (2-FG) as a novel putative biomarker for coffee consumption. We relatively quantified 2-FG in the urine of coffee drinkers and investigated its origin, metabolism, and excretion kinetics. When searching for its potential precursors, we found different furan derivatives in coffee products, which are known to get metabolized to 2-FG. Maximal urinary excretion of 2-FG occurred 2 h after consumption (p = 0.0002) and returned to baseline after 24 h (p = 0.74). The biomarker was not excreted after consumption of coffee substitutes such as tea and chicory coffee and might therefore be a promising acute biomarker for the detection of coffee consumption in human urine. PMID:26357997

  11. Neuroimaging Biomarkers for Psychosis

    Science.gov (United States)

    Hager, Brandon M.

    2015-01-01

    Background Biomarkers provide clinicians with a predictable model for the diagnosis, treatment and follow-up of medical ailments. Psychiatry has lagged behind other areas of medicine in the identification of biomarkers for clinical diagnosis and treatment. In this review, we investigated the current state of neuroimaging as it pertains to biomarkers for psychosis. Methods We reviewed systematic reviews and meta-analyses of the structural (sMRI), functional (fMRI), diffusion-tensor (DTI), Positron emission tomography (PET) and spectroscopy (MRS) studies of subjects at-risk or those with an established schizophrenic illness. Only articles reporting effect-sizes and confidence intervals were included in an assessment of robustness. Results Out of the identified meta-analyses and systematic reviews, 21 studies met the inclusion criteria for assessment. There were 13 sMRI, 4 PET, 3 MRS, and 1 DTI studies. The search terms included in the current review encompassed familial high risk (FHR), clinical high risk (CHR), First episode (FES), Chronic (CSZ), schizophrenia spectrum disorders (SSD), and healthy controls (HC). Conclusions Currently, few neuroimaging biomarkers can be considered ready for diagnostic use in patients with psychosis. At least in part, this may be related to the challenges inherent in the current symptom-based approach to classifying these disorders. While available studies suggest a possible value of imaging biomarkers for monitoring disease progression, more systematic research is needed. To date, the best value of imaging data in psychoses has been to shed light on questions of disease pathophysiology, especially through the characterization of endophenotypes. PMID:25883891

  12. Catabolism of circulating enzymes: plasma clearance, endocytosis, and breakdown of lactate dehydrogenase-1 in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Smit, M.J.; Beekhuis, H.; Duursma, A.M.; Bouma, J.M.; Gruber, M.

    1988-12-01

    Lactate dehydrogenase-1, intravenously injected into rabbits, was cleared with first-order kinetics (half-life 27 min), until at least 80% of the injected activity had disappeared from plasma. Radioactivity from injected SVI-labeled enzyme disappeared at this same rate. Trichloroacetic-acid-soluble breakdown products started to appear in the circulation shortly after injection of the labeled enzyme. Body scans of the rabbits for 80 min after injection of T I-labeled enzyme revealed rapid accumulation of label in the liver, peaking 10-20 min after injection. Subsequently, activity in the liver declined and radioactivity (probably labeled breakdown products of low molecular mass) steadily accumulated in the bladder. Tissue fractionation of liver, 19 min after injection of labeled enzyme, indicated that the radioactivity was present both in endosomes and in lysosomes, suggesting uptake by endocytosis, followed by breakdown in the lysosomes. Measurements of radioactivity in liver and plasma suggest that the liver is responsible for the breakdown of at least 75% of the injected enzyme. Radioautography of tissue sections of liver and spleen showed accumulated radioactivity in sinusoidal liver cells and red pulpa, respectively. These results are very similar to those for lactate dehydrogenase-5, creatine kinase MM, and several other enzymes that we have previously studied in rats.

  13. Catabolism of circulating enzymes: plasma clearance, endocytosis, and breakdown of lactate dehydrogenase-1 in rabbits.

    Science.gov (United States)

    Smit, M J; Beekhuis, H; Duursma, A M; Bouma, J M; Gruber, M

    1988-12-01

    Lactate dehydrogenase-1 (EC 1.1.1.27), intravenously injected into rabbits, was cleared with first-order kinetics (half-life 27 min), until at least 80% of the injected activity had disappeared from plasma. Radioactivity from injected 125I-labeled enzyme disappeared at this same rate. Trichloroacetic-acid-soluble breakdown products started to appear in the circulation shortly after injection of the labeled enzyme. Body scans of the rabbits for 80 min after injection of 131I-labeled enzyme revealed rapid accumulation of label in the liver, peaking 10-20 min after injection. Subsequently, activity in the liver declined and radioactivity (probably labeled breakdown products of low molecular mass) steadily accumulated in the bladder. Tissue fractionation of liver, 19 min after injection of labeled enzyme, indicated that the radioactivity was present both in endosomes and in lysosomes, suggesting uptake by endocytosis, followed by breakdown in the lysosomes. Measurements of radioactivity in liver and plasma suggest that the liver is responsible for the breakdown of at least 75% of the injected enzyme. Radioautography of tissue sections of liver and spleen showed accumulated radioactivity in sinusoidal liver cells and red pulpa, respectively. These results are very similar to those for lactate dehydrogenase-5, creatine kinase MM, and several other enzymes that we have previously studied in rats. PMID:3197286

  14. Catabolism of circulating enzymes: plasma clearance, endocytosis, and breakdown of lactate dehydrogenase-1 in rabbits

    International Nuclear Information System (INIS)

    Lactate dehydrogenase-1, intravenously injected into rabbits, was cleared with first-order kinetics (half-life 27 min), until at least 80% of the injected activity had disappeared from plasma. Radioactivity from injected 125I-labeled enzyme disappeared at this same rate. Trichloroacetic-acid-soluble breakdown products started to appear in the circulation shortly after injection of the labeled enzyme. Body scans of the rabbits for 80 min after injection of 131I-labeled enzyme revealed rapid accumulation of label in the liver, peaking 10-20 min after injection. Subsequently, activity in the liver declined and radioactivity (probably labeled breakdown products of low molecular mass) steadily accumulated in the bladder. Tissue fractionation of liver, 19 min after injection of labeled enzyme, indicated that the radioactivity was present both in endosomes and in lysosomes, suggesting uptake by endocytosis, followed by breakdown in the lysosomes. Measurements of radioactivity in liver and plasma suggest that the liver is responsible for the breakdown of at least 75% of the injected enzyme. Radioautography of tissue sections of liver and spleen showed accumulated radioactivity in sinusoidal liver cells and red pulpa, respectively. These results are very similar to those for lactate dehydrogenase-5, creatine kinase MM, and several other enzymes that we have previously studied in rats

  15. Lignans from Carthamus tinctorius suppress tryptophan breakdown via indoleamine 2,3-dioxygenase.

    Science.gov (United States)

    Kuehnl, Susanne; Schroecksnadel, Sebastian; Temml, Veronika; Gostner, Johanna M; Schennach, Harald; Schuster, Daniela; Schwaiger, Stefan; Rollinger, Judith M; Fuchs, Dietmar; Stuppner, Hermann

    2013-10-15

    Seed extracts of Carthamus tinctorius L. (Asteraceae), safflower, have been traditionally used to treat coronary disease, thrombotic disorders, and menstrual problems but also against cancer and depression. A possible effect of C. tinctorius compounds on tryptophan-degrading activity of enzyme indoleamine 2,3-dioxygenase (IDO) could explain many of its activities. To test for an effect of C. tinctorius extracts and isolated compounds on cytokine-induced IDO activity in immunocompetent cells in vitro methanol and ethylacetate seed extracts were prepared from cold pressed seed cakes of C. tinctorius and three lignan derivatives, trachelogenin, arctigenin and matairesinol were isolated. The influence on tryptophan breakdown was investigated in peripheral blood mononuclear cells (PBMCs). Effects were compared to neopterin production in the same cellular assay. Both seed extracts suppressed tryptophan breakdown in stimulated PBMC. The three structurally closely related isolates exerted differing suppressive activity on PBMC: arctigenin (IC50 26.5μM) and trachelogenin (IC50 of 57.4μM) showed higher activity than matairesinol (IC50 >200μM) to inhibit tryptophan breakdown. Effects on neopterin production were similar albeit generally less strong. Data show an immunosuppressive property of compounds which slows down IDO activity. The in vitro results support the view that some of the anti-inflammatory, anticancer and antidepressant properties of C. tinctorius lignans might relate to their suppressive influence on tryptophan breakdown. PMID:23867649

  16. Drell-Yan diffraction: breakdown of QCD factorization

    Energy Technology Data Exchange (ETDEWEB)

    Pasechnik, R.S. [Lund University, Theoretical High Energy Physics, Department of Astronomy and Theoretical Physics, Lund (Sweden); Kopeliovich, B.Z. [Universidad Tecnica Federico Santa Maria, Departamento de Fisica, Valparaiso (Chile); Instituto de Estudios Avanzados en Ciencias e Ingenieria, Valparaiso (Chile); Centro Cientifico-Tecnologico de Valparaiso, Valparaiso (Chile)

    2011-12-15

    We consider the diffractive Drell-Yan process in proton-(anti)proton collisions at high energies in the color dipole approach. The calculations are performed at forward rapidities of the leptonic pair. The effect of eikonalization of the universal ''bare'' dipole-target elastic amplitude in the saturation regime takes into account the principal part of the gap survival probability. We present predictions for the total and differential cross sections of the single-diffractive lepton-pair production at RHIC and LHC energies. We analyze implications of the QCD factorization breakdown in the diffractive Drell-Yan process, which is caused by a specific interplay of the soft and hard interactions, resulting in rather unusual properties of the corresponding observables. (orig.)

  17. [Key laboratory diagnostic biomarkers of coronary atherosclerosis].

    Science.gov (United States)

    Ragino, Iu I; Cherniavskiĭ, A M; Eremenko, N V; Shakhtshneĭder, E V; Polonskaia, Ia V; Tsymbal, S Iu; Ivanova, M V; Voevoda, M I

    2011-01-01

    Laboratory lipid and lipoprotein biomarkers (total cholesterol - CH, triglycerides - TG, low-density and high-density lipoprotein cholesterol- LDL-CH, HDL-CH, apolipoproteins B and A1 - apoB, apoA1), carbohydrate biomarkers (plasma glucose, basal insulin), high sensitive C-reactive protein (hsCRP) and oxidative biomarkers (basal level of lipid peroxidation [LPO] products in LDL, LDL resistance to oxidation in vitro, oxidative modification of apoLDL and level of LDL lipophilic antioxidants) were studied in 388 men aged 42-70 years: 96 citizens of Western Siberia with angiographically documented coronary atherosclerosis and coronary heart disease (CHD); 292 men of population sample of citizens of Novosibirsk, including 44 men with CHD confirmed by standardized criteria and methods. Significant associations were found of coronary atherosclerosis and CHD with laboratory diagnostic biomarkers like blood levels of HDL-CH, TG, apoB, apoA1, basal insulin, hsCRP and basal level of LPO products in LDL and LDL resistance to oxidation. PMID:21627612

  18. QCD emergent from spontaneous breakdown of relativity

    CERN Document Server

    Nishimura, Kimihide

    2016-01-01

    Spontaneous violation of relativistic invariance of the vacuum can derive quantum chromodynamics from an U(1) Higgs model including fermions, if the emergent theory is Lorentz invariant. In this model, the vacuum becomes anisotropic, and a fermion created on a triplet of spin-one vacua acquires degeneracy analogous to the color degrees of freedom. The Nambu-Goldstone bosons originating from the breakdown of rotational symmetry provide the quasi fermions with SU(3)$\\times$U(1) effective interactions, which are interpretable as mediated by gluons and photons. The confinement of quasi quarks as well as that of Nambu-Goldstone gluons follow from the Lorentz invariance of the emergent theory.

  19. Need for spontaneous breakdown of chiral symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-07-15

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately.

  20. Ergodicity breakdown and scaling from single sequences

    Energy Technology Data Exchange (ETDEWEB)

    Kalashyan, Armen K. [Center for Nonlinear Science, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); Buiatti, Marco [Laboratoire de Neurophysique et Physiologie, CNRS UMR 8119 Universite Rene Descartes - Paris 5 45, rue des Saints Peres, 75270 Paris Cedex 06 (France); Cognitive Neuroimaging Unit - INSERM U562, Service Hospitalier Frederic Joliot, CEA/DRM/DSV, 4 Place du general Leclerc, 91401 Orsay Cedex (France); Grigolini, Paolo [Center for Nonlinear Science, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); Dipartimento di Fisica ' E.Fermi' - Universita di Pisa and INFM, Largo Pontecorvo 3, 56127 Pisa (Italy); Istituto dei Processi Chimico, Fisici del CNR Area della Ricerca di Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy)], E-mail: grigo@df.unipi.it

    2009-01-30

    In the ergodic regime, several methods efficiently estimate the temporal scaling of time series characterized by long-range power-law correlations by converting them into diffusion processes. However, in the condition of ergodicity breakdown, the same methods give ambiguous results. We show that in such regime, two different scaling behaviors emerge depending on the age of the windows used for the estimation. We explain the ambiguity of the estimation methods by the different influence of the two scaling behaviors on each method. Our results suggest that aging drastically alters the scaling properties of non-ergodic processes.

  1. RF Breakdown in Drift Tube Linacs

    CERN Document Server

    Stovall, J; Lown, R

    2009-01-01

    The highest RF electric field in drift-tube linacs (DTLs) often occurs on the face of the first drift tube. Typically this drift tube contains a quadrupole focusing magnet whose fringing fields penetrate the face of the drift tube parallel to the RF electric fields in the accelerating gap. It has been shown that the threshold for RF breakdown in RF cavities may be reduced in the presence of a static magnetic field. This note offers a “rule of thumb” for picking the maximum “safe” surface electric field in DTLs based on these measurements.

  2. Theoretical studies on secondary breakdowns in a GIS

    Energy Technology Data Exchange (ETDEWEB)

    Rao, M.M.; Naidu, M.S. [Indian Inst. of Science, Bangalore (India). Dept. of High Voltage Engineering; Satyanarayana, S.

    1997-12-31

    The very fast transient overvoltages (VFTO) which are caused by switching operations in a gas-insulated substation (GIS) were discussed. VFTOs can lead to secondary electrical breakdowns within a GIS. The VFTO levels were estimated at different positions in a GIS during different switching operations. It was shown that the VFTO pattern changes after breakdown. The importance of understanding the VFTO level after secondary breakdown in the design of substations was stressed. 6 refs., 8 figs.

  3. Numerical Study on Atmospheric Pressure DBD in Helium: Single-breakdown and Multi-breakdown Discharges%Numerical Study on Atmospheric Pressure DBD in Helium: Single-breakdown and Multi-breakdown Discharges

    Institute of Scientific and Technical Information of China (English)

    王小华; 杨爱军; 荣命哲; 刘定新

    2011-01-01

    A 1-D fluid model for homogeneous dielectric barrier discharge (DBD) in helium is presented, aimed at unraveling the spatial-temporal characteristics of two basic discharge regimes: single-breakdown and multi-breakdown discharges. Discharge currents, gap voltages, charge densities, electron temperature and electric field profiles of the two regimes make it clear that these two regimes are qualitatively different. It is found that the multi-breakdown discharge has a more homogeneous flux on dielectrics compared to the single-breakdown discharge.

  4. Measuring protein breakdown in individual proteins in vivo

    DEFF Research Database (Denmark)

    Holm, Lars; Kjær, Michael

    2010-01-01

    is that the proteins of interest are the site of measurement. Hence, the application initially demands the proteins to be labeled with stable isotopically labeled amino acids. Subsequently, the loss of label from the proteins will be dependent on the protein breakdown rate when no labeled amino acids......PURPOSE OF REVIEW: To outline different approaches of how protein breakdown can be quantified and to present a new approach to determine the fractional breakdown rate of individual slow turnover proteins in vivo. RECENT FINDINGS: None of the available methods for determining protein breakdown can...

  5. Vortex ring breakdown induced by topographic forcing

    Energy Technology Data Exchange (ETDEWEB)

    Geiser, J; Kiger, K T, E-mail: kkiger@umd.edu [Department of Mechanical Engineering, University of Maryland, College Park, MD 20910 (United States)

    2011-12-22

    Detailed measurements of the vortex breakdown within a strongly forced impinging jet are presented, with the goal of studying the effects of a small topographic disturbance on the breakdown and turbulence structure. This work is related to an ongoing effort to understand the dynamics of sediment suspension within a landing rotorcraft where a mobile boundary is subject to rapid erosion and deposition. The current work compares the results of a uniform surface to that of a small radial fence placed upstream of the vortex impingement location. The result is a dramatic increase in the coherence of the three-dimensional looping exhibited by the secondary vortex, leading to a more organized and strongly perturbed mean flow. Specifically, a triple decomposition of the velocity fluctuations indicates a very intense periodic stress in the vicinity of the impingement site, followed by a significant decay. Conversely, the random component of the fluctuating stresses gradually increases to modest levels as the coherent contributions decrease, eventually becoming greater than the coherent stress. The fence produces a bifurcation in the flow through the perturbation of the secondary vortex, which in turn creates a high-and low-speed streak on either side of the fence. The subsequent dynamics leads to increased fluctuating stress in the high-speed region, and a dramatically lower stress in the low-speed region, favoring preferential erosion on either side of the topographic disturbance.

  6. Runaway breakdown and electric discharges in thunderstorms

    International Nuclear Information System (INIS)

    This review concerns the theory of the avalanche multiplication of high-energy (0.1 - 10 MeV) electrons in a neutral material, a newly discovered phenomenon known as runaway breakdown (RB). In atmospheric conditions RB takes place at electric fields an order of magnitude weaker than those needed for normal breakdown in air. Experimental work of the past few years has shown that RB determines the maximum electric field strength in thunderclouds and is behind a variety of phenomena newly observed in thunderstorm atmosphere, such as giant high-altitude discharges between thunderclouds and the ionosphere, anomalous amplifications of X-ray emission, intense bursts of gamma radiation, etc. These phenomena are becoming increasingly active areas of study. A necessary condition for the occurrence of runaway avalanche is the presence of high energy seed electrons. In the atmosphere, these are cosmic ray secondary electrons. Therefore, the observed effects reflect the close relationship between cosmic rays and electrodynamic processes in the thunderstorm atmosphere. The first laboratory results on RB are also presented. Further studies in this area may be of interest for high-current electronics. (reviews of topical problems)

  7. Biomarkers for pancreatic carcinogenesis

    OpenAIRE

    Hustinx, S.R.

    2007-01-01

    Pancreatic cancer is a devastating disease. Most pancreatic cancers (approximately 85%) are diagnosed at a late, incurable stage. The poor prognosis and late presentation of pancreatic cancer patients underscore the importance of early detection, which is the sine qua non for the fight against pancreatic cancer. It is hoped for the future that the understanding of genetic alterations will lead to the rapid discovery of an effective biomarker of pancreatic carcinogenesis. In this thesis we vis...

  8. BLOOD BIOMARKERS FOR EVALUATION OF PERINATAL ENCEPHALOPATHY

    Directory of Open Access Journals (Sweden)

    Ernest Marshall Graham

    2016-07-01

    Full Text Available Recent research in identification of brain injury after trauma shows many possible blood biomarkers that may help identify the fetus and neonate with encephalopathy. Traumatic brain injury shares many common features with perinatal hypoxic-ischemic encephalopathy. Trauma has a hypoxic component, and one of the 1st physiologic consequences of moderate-severe traumatic brain injury is apnea. Trauma and hypoxia-ischemia initiate an excitotoxic cascade and free radical injury followed by the inflammatory cascade, producing injury in neurons, glial cells and white matter. Increased excitatory amino acids, lipid peroxidation products and alteration in microRNAs and inflammatory markers are common to both traumatic brain injury and perinatal encephalopathy. The blood-brain barrier is disrupted in both leading to egress of substances normally only found in the central nervous system. Brain exosomes may represent ideal biomarker containers, as RNA and protein transported within the vesicles are protected from enzymatic degradation. Evaluation of fetal or neonatal brain derived exosomes that cross the blood-brain barrier and circulate peripherally has been referred to as the liquid brain biopsy. A multiplex of serum biomarkers could improve upon the current imprecise methods of identifying fetal and neonatal brain injury such as fetal heart rate abnormalities, meconium, cord gases at delivery, and Apgar scores. Quantitative biomarker measurements of perinatal brain injury and recovery could lead to operative delivery only in the presence of significant fetal risk, triage to appropriate therapy after birth and measure the effectiveness of treatment.

  9. Blood Biomarkers for Evaluation of Perinatal Encephalopathy

    Science.gov (United States)

    Graham, Ernest M.; Burd, Irina; Everett, Allen D.; Northington, Frances J.

    2016-01-01

    Recent research in identification of brain injury after trauma shows many possible blood biomarkers that may help identify the fetus and neonate with encephalopathy. Traumatic brain injury shares many common features with perinatal hypoxic-ischemic encephalopathy. Trauma has a hypoxic component, and one of the 1st physiologic consequences of moderate-severe traumatic brain injury is apnea. Trauma and hypoxia-ischemia initiate an excitotoxic cascade and free radical injury followed by the inflammatory cascade, producing injury in neurons, glial cells and white matter. Increased excitatory amino acids, lipid peroxidation products, and alteration in microRNAs and inflammatory markers are common to both traumatic brain injury and perinatal encephalopathy. The blood-brain barrier is disrupted in both leading to egress of substances normally only found in the central nervous system. Brain exosomes may represent ideal biomarker containers, as RNA and protein transported within the vesicles are protected from enzymatic degradation. Evaluation of fetal or neonatal brain derived exosomes that cross the blood-brain barrier and circulate peripherally has been referred to as the “liquid brain biopsy.” A multiplex of serum biomarkers could improve upon the current imprecise methods of identifying fetal and neonatal brain injury such as fetal heart rate abnormalities, meconium, cord gases at delivery, and Apgar scores. Quantitative biomarker measurements of perinatal brain injury and recovery could lead to operative delivery only in the presence of significant fetal risk, triage to appropriate therapy after birth and measure the effectiveness of treatment. PMID:27468268

  10. Failure reasons investigations of dumping conveyor breakdown

    Directory of Open Access Journals (Sweden)

    E. Rusiński

    2007-07-01

    Full Text Available Purpose: The main purposes of the paper are to discuss designing and exploitation problems of machines used in strip mines and investigation of its reasons based on steering frame brake-down of the dumping conveyor.Design/methodology/approach: Numerical and experimental approach was used to investigate reasons of the break-down of the dumping conveyor. Numerical simulations based on the finite element method were used. Fractographic and microscopic evaluation and chemical analysis, were used to perform material evaluations. The objectives are achieved by analysis of the numerical simulations results of the broken part of machine and data coming from material evaluations. Based on the mentioned results conclusions concerning results of the failure were given. Additionally the new design of the steering frame half-shafts systems was discussedFindings: The causes of break-down of the steering frame of dumping conveyor were found. Designing and manufacturing problems were the main reasons of the failure. The half shafts systems in undercarriages of the open pit machines are prone to break-downs. They require detailed analysis to be successfully implemented into steering system. Recommendations for the single shaft system are given in the paper.Research limitations/implications: in the half-shaft undercarriage system, the friction in the supporting areas limits horizontal forces acting on safetying. Investigations of the static and sliding friction coefficients should be performed to estimate correct forces and optimal designing rules.Practical implications: The study provides practical implication into designing of half-shafts undercarriage systems and their safetyings. Discussed design of the safetying should be redesigned or the half-shaft system should be changed into one shaft design.Originality/value: The paper provides information backed by evaluation and test results, stating the nexus of causes of the dumping conveyor failure. The

  11. Symmetry breakdown and coupling constants of leptons

    Directory of Open Access Journals (Sweden)

    Gil C. Marques

    2007-06-01

    Full Text Available Based on a new approach to symmetries of the fundamental interactions we deal, in this paper, with the electroweak interactions of leptons. We show that the coupling constants, arising in the way leptons are coupled to intermediate bosons, can be understood as parameters associated to the breakdown of SU(2 and parity symmetries. The breakdown of both symmetries is characterized by a new parameter (the asymetry parameter of the electroweak interactions. This parameter gives a measure of the strength of breakdown of symmetries. We analyse the behaviour of the theory for three values of this parameter. The most relevant value is the one for which only the electromagnetic interactions do not break parity (the maximally allowed left-right asymetric theory. Maximamally allowed parity asymmetry is a requirement that is met for a value of Weinberg's theta-angle that is quite close to the experimental value of this parameter.Com base em uma formulação nova para simetrias das interações fundamentais nós lidamos, neste trabalho, com interações eletrofracas de leptons. Mostramos que as constantes do acoplamento, associadas aos acoplamentos de bósons intermediários, podem ser entendidas como parâmetros associados à quebra de simetrias SU(2 e paridade. A quebra de ambas as simetrias é caracterizada por um parâmetro novo (o parâmetro de assimetria das interações eletrofracas. Este parâmetro dá uma medida da intensidade com que a simetria é quebrada. Analisamos o comportamento da teoria para três valores deste parâmetro. O valor mais relevante é aquele para o qual apenas as interações eletromagnéticas não quebram a paridade (a teoria assimétrica esquerda-direita permitida da maneira máxima. A assimetria máxima permitida é uma exigência que leva a um ângulo de Weinberg cujo valor é próximo daquele observado experimentalmente.

  12. Biomarker strategies to evaluate the environmental effects of chemicals.

    OpenAIRE

    Walker, C H

    1998-01-01

    Environmental risk assessment of chemicals depends on the production of toxicity data for surrogate species of mammals, birds, and fish and on making comparisons between these and estimated or predicted environmental concentrations of the chemicals. This paper gives an overview of biomarker assays and strategies that might be used as alternatives, that is, to replace, reduce, or refine currently used ecotoxicity tests that cause suffering to vertebrates. In the present context a biomarker is ...

  13. Experimental study of the breakdown phase in coaxial plasma guns

    International Nuclear Information System (INIS)

    The problem of the dielectric breakdown of gases and its relevance in plasma devices is discussed, and preliminary results of an experimental study upon the spatial location and time evolution of the breakdown phase in a plasma focus device are given

  14. STRUCTURES OF CONFINED VORTEX BREAKDOWN IN CONSTANT DIAMETER PIPE FLOW

    Institute of Scientific and Technical Information of China (English)

    WANG Ze; CHEN Shan-qun

    2009-01-01

    Numerical solutions of three-dimensional, incompressible and unsteady Navier-Stokes equations for constant diameter swirling pipe flows are used to study vortex breakdown, including the detailed flow structures in the bubble domain and the "tail" behind the bubble during the vortex breakdown, and a comparison is made between the numerical solutions and the experimental results.

  15. Vortex breakdown in a truncated conical bioreactor

    Science.gov (United States)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2015-12-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air-water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, Hw, and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as Hw varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small Hw, the AMF effect dominates. As Hw increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors.

  16. Development of Electrical Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2006-01-01

    Full Text Available Power transformers are key equipment for transfer and distribution of the electric power. Considering the significance of the power transformers in the electric system, their price and possible damages occurred by accidents, it is necessary to pay attention to their higher prevention. To prevent failure states of transformers, we perform different types ofmeasurements. They shall illustrate a momentary state of the measured equipment and if necessary to draw attention in advance to changes of parameters, which have specific relationship to no-failure operation of the equipment. The conditions under which breakdown of composite liquid/ solid insulation can occur, e.g. in transformer, play an important role in designing such insulation. The liquid, mainly mineral oil, generally constitutes the weakest part of insulation and a great amount of work has been devoted to the study of streamers, which appear in the gaseous phase, and most often are triggering the failure of insulation.

  17. On the electric breakdown in liquid argon at centimeter scale

    Science.gov (United States)

    Auger, M.; Blatter, A.; Ereditato, A.; Goeldi, D.; Janos, S.; Kreslo, I.; Luethi, M.; von Rohr, C. Rudolf; Strauss, T.; Weber, M. S.

    2016-03-01

    We present a study on the dependence of electric breakdown discharge properties on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

  18. Breakdown voltage of metal-oxide resistors in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Bagby, L. F. [Fermilab; Gollapinni, S. [Kansas State U.; James, C. C. [Fermilab; Jones, B. J.P. [MIT; Jostlein, H. [Fermilab; Lockwitz, S. [Fermilab; Naples, D. [Pittsburgh U.; Raaf, J. L. [Fermilab; Rameika, R. [Fermilab; Schukraft, A. [Fermilab; Strauss, T. [Bern U., LHEP; Weber, M. S. [Bern U., LHEP; Wolbers, S. A. [Fermilab

    2014-11-07

    We characterized a sample of metal-oxide resistors and measured their breakdown voltage in liquid argon by applying high voltage (HV) pulses over a 3 second period. This test mimics the situation in a HV-divider chain when a breakdown occurs and the voltage across resistors rapidly rise from the static value to much higher values. All resistors had higher breakdown voltages in liquid argon than their vendor ratings in air at room temperature. Failure modes range from full destruction to coating damage. In cases where breakdown was not catastrophic, subsequent breakdown voltages were lower in subsequent measuring runs. One resistor type withstands 131 kV pulses, the limit of the test setup.

  19. Laboratory demonstration of runaway electron breakdown of air

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, A.V., E-mail: alex@lpi.ru [P.N. Lebedev Physical Institute, RAS, 53 Lenin Avenue, 119991 Moscow (Russian Federation); Mesyats, G.A.; Zybin, K.P. [P.N. Lebedev Physical Institute, RAS, 53 Lenin Avenue, 119991 Moscow (Russian Federation); Reutova, A.G.; Shpak, V.G.; Shunailov, S.A.; Yalandin, M.I. [Institute of Electrophysics, UB RAS, 106 Amundsen Str., 620016 Ekaterinburg (Russian Federation)

    2011-07-18

    Results of experiments demonstrating the phenomenon of runaway electron breakdown of atmospheric air under laboratory conditions are presented. As the discharge-initiating electron beam of duration ∼50 ps had passed through the electrode gap, a runaway electron avalanche current was detected in the electrode gap downstream of the anode grid and then breakdown occurred with picosecond stability. The maximum electron energy and the duration of the avalanche current corresponded to theoretical notions about the runaway electron breakdown of atmospheric air in a strong electric field. Breakdown did not occur at all or was considerably delayed when no initiating beam was used. -- Highlights: → Runaway electron air breakdown in laboratory experiments is demonstrated. → The discharge is initiated by electron beam of 50 ps duration. → The maximum electron energy and avalanche current duration correspond to the theory.

  20. On the Electric Breakdown in Liquid Argon at Centimeter Scale

    CERN Document Server

    Auger, M; Ereditato, A; Goeldi, D; Janos, S; Kreslo, I; Luethi, M; von Rohr, C Rudolf; Strauss, T; Weber, M S

    2015-01-01

    We present a study on the dependence of electric breakdown discharge parameters on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

  1. Biomarker Identification Using Text Mining

    Directory of Open Access Journals (Sweden)

    Hui Li

    2012-01-01

    Full Text Available Identifying molecular biomarkers has become one of the important tasks for scientists to assess the different phenotypic states of cells or organisms correlated to the genotypes of diseases from large-scale biological data. In this paper, we proposed a text-mining-based method to discover biomarkers from PubMed. First, we construct a database based on a dictionary, and then we used a finite state machine to identify the biomarkers. Our method of text mining provides a highly reliable approach to discover the biomarkers in the PubMed database.

  2. Biomarkers in Prostate Cancer Epidemiology

    Directory of Open Access Journals (Sweden)

    Mudit Verma

    2011-09-01

    Full Text Available Understanding the etiology of a disease such as prostate cancer may help in identifying populations at high risk, timely intervention of the disease, and proper treatment. Biomarkers, along with exposure history and clinical data, are useful tools to achieve these goals. Individual risk and population incidence of prostate cancer result from the intervention of genetic susceptibility and exposure. Biochemical, epigenetic, genetic, and imaging biomarkers are used to identify people at high risk for developing prostate cancer. In cancer epidemiology, epigenetic biomarkers offer advantages over other types of biomarkers because they are expressed against a person’s genetic background and environmental exposure, and because abnormal events occur early in cancer development, which includes several epigenetic alterations in cancer cells. This article describes different biomarkers that have potential use in studying the epidemiology of prostate cancer. We also discuss the characteristics of an ideal biomarker for prostate cancer, and technologies utilized for biomarker assays. Among epigenetic biomarkers, most reports indicate GSTP1 hypermethylation as the diagnostic marker for prostate cancer; however, NKX2-5, CLSTN1, SPOCK2, SLC16A12, DPYS, and NSE1 also have been reported to be regulated by methylation mechanisms in prostate cancer. Current challenges in utilization of biomarkers in prostate cancer diagnosis and epidemiologic studies and potential solutions also are discussed.

  3. Blood biomarkers in the early stage of cerebral ischemia.

    Science.gov (United States)

    Maestrini, I; Ducroquet, A; Moulin, S; Leys, D; Cordonnier, C; Bordet, R

    2016-03-01

    In ischemic stroke patients, blood-based biomarkers may be applied for the diagnosis of ischemic origin and subtype, prediction of outcomes and targeted treatment in selected patients. Knowledge of the pathophysiology of cerebral ischemia has led to the evaluation of proteins, neurotransmitters, nucleic acids and lipids as potential biomarkers. The present report focuses on the role of blood-based biomarkers in the early stage of ischemic stroke-within 72h of its onset-as gleaned from studies published in English in such patients. Despite growing interest in their potential role in clinical practice, the application of biomarkers for the management of cerebral ischemia is not currently recommended by guidelines. However, there are some promising clinical biomarkers, as well as the N-methyl-d-aspartate (NMDA) peptide and NMDA-receptor (R) autoantibodies that appear to identify the ischemic nature of stroke, and the glial fibrillary acidic protein (GFAP) that might be able to discriminate between acute ischemic and hemorrhagic strokes. Moreover, genomics and proteomics allow the characterization of differences in gene expression, and protein and metabolite production, in ischemic stroke patients compared with controls and, thus, may help to identify novel markers with sufficient sensitivity and specificity. Additional studies to validate promising biomarkers and to identify novel biomarkers are needed. PMID:26988891

  4. Mask characterization for CDU budget breakdown in advanced EUV lithography

    Science.gov (United States)

    Nikolsky, Peter; Strolenberg, Chris; Nielsen, Rasmus; Nooitgedacht, Tjitte; Davydova, Natalia; Yang, Greg; Lee, Shawn; Park, Chang-Min; Kim, Insung; Yeo, Jeong-Ho

    2012-11-01

    As the ITRS Critical Dimension Uniformity (CDU) specification shrinks, semiconductor companies need to maintain a high yield of good wafers per day and a high performance (and hence market value) of finished products. This cannot be achieved without continuous analysis and improvement of on-product CDU as one of the main drivers for process control and optimization with better understanding of main contributors from the litho cluster: mask, process, metrology and scanner. In this paper we will demonstrate a study of mask CDU characterization and its impact on CDU Budget Breakdown (CDU BB) performed for an advanced EUV lithography with 1D and 2D feature cases. We will show that this CDU contributor is one of the main differentiators between well-known ArFi and new EUV CDU budgeting principles. We found that reticle contribution to intrafield CDU should be characterized in a specific way: mask absorber thickness fingerprints play a role comparable with reticle CDU in the total reticle part of the CDU budget. Wafer CD fingerprints, introduced by this contributor, may or may not compensate variations of mask CD's and hence influence on total mask impact on intrafield CDU at the wafer level. This will be shown on 1D and 2D feature examples in this paper. Also mask stack reflectivity variations should be taken into account: these fingerprints have visible impact on intrafield CDs at the wafer level and should be considered as another contributor to the reticle part of EUV CDU budget. We observed also MEEF-through-field fingerprints in the studied EUV cases. Variations of MEEF may also play a role for the total intrafield CDU and may be taken into account for EUV Lithography. We characterized MEEF-through-field for the reviewed features, the results to be discussed in our paper, but further analysis of this phenomenon is required. This comprehensive approach to characterization of the mask part of EUV CDU characterization delivers an accurate and integral CDU Budget

  5. Real-time measurement of hyperpolarized lactate production and efflux as a biomarker of tumor aggressiveness in an MR compatible 3D cell culture bioreactor.

    Science.gov (United States)

    Sriram, Renuka; Van Criekinge, Mark; Hansen, Ailin; Wang, Zhen J; Vigneron, Daniel B; Wilson, David M; Keshari, Kayvan R; Kurhanewicz, John

    2015-09-01

    We have developed a 3D cell/tissue culture bioreactor compatible with hyperpolarized (HP) (13)C MR and interrogated HP [1-(13)C]lactate production and efflux in human renal cell carcinoma (RCC) cells. This platform is capable of resolving intracellular and extracellular HP lactate pools, allowing the kinetic measurement of lactate production and efflux in the context of cancer aggressiveness and response to therapy. HP (13)C MR studies were performed on three immortalized human renal cell lines: HK2, a normal renal proximal tubule cell line from which a majority of RCCs arise, UMRC6, a cell line derived from a localized RCC, and UOK262, an aggressive and metastatic RCC. The intra- (Lacin ) and extracellular (Lacex ) HP lactate signals were robustly resolved in dynamic (13)C spectra of the cell lines due to a very small but reproducible chemical shift difference (0.031 ± 0.0005 ppm). Following HP [1-(13)C]pyruvate delivery, the ratio of HP Lacin /Lacex was significantly lower for UOK262 cells compared with both UMRC6 and HK2 cells due to a significant (p culture bioreactor to study not only cellular metabolism but also transport. Additionally, this platform offers a sophisticated way to follow therapeutic interventions and screen novel therapies that target lactate export. PMID:26202449

  6. Behavioral and spermatogenic hybrid male breakdown in Nasonia.

    Science.gov (United States)

    Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

    2010-03-01

    Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

  7. Bioenergetics breakdown in Alzheimer's disease: targets for new therapies.

    Science.gov (United States)

    Saxena, Uday

    2011-01-01

    Alzheimer's disease is rapidly growing worldwide and yet there is no cure for it. Currently available drugs only provide symptomatic relief and do not intervene in disease process sufficiently enough to prevent or cure it. Characteristic features of this disease are decline in neuronal mass and cognitive functions. The most dominant hypothesis proposed for pathogenesis of this disease is called "amyloid hypothesis". It states that excessive production of amyloid peptides called abeta peptides (Aβ) is the underlying cause of neuronal death and dysfunction. However, recent drugs designed based on amyloid hypothesis have failed in clinical trails, demanding fresh assessment. Early and persistent molecular events in this disease progression are energy deficiency and high oxidative stress in the neurons. Our review will put together a disease model based on known human and animal data with regards to breakdown in neuronal energy generation. The model will integrate energy deficits as the cause of neuronal dysfunction and abeta peptide production culminating in catastrophic loss of cognitive functions. Finally, based on this model, we will also suggest enzyme targets in neuronal bioenergetics pathway for design and development of new disease modifying therapies. PMID:21760971

  8. Experimental Study on High Electrical Breakdown of Water Dielectric

    Institute of Scientific and Technical Information of China (English)

    Zhang Zicheng; Zhang Jiande; Yang Jianhua

    2005-01-01

    By means of a coaxial apparatus, pressurized water breakdown experiments with microsecond charging have been carried out with different surface roughness of electrodes and different ethylene glycol concentrations of ethylene glycol/water mixture. The experimental results about the breakdown stress and the effective time are presented. The breakdown stress is normalized to the situation that the effective time is transformed to 1 μs and analyzed. The conclusions are as follows: (1) the breakdown stress formula is modified to E = 0.561MA-1/10t-1eff/NP1/8; (2)the coefficient M is significantly increased by surface polishing and ethylene glycol additive; (3) it is accumulative for the capacity of improving electrical breakdown strength for surface polishing,ethylene glycol additive, and pressurization, of which pressurization is the most effective method;(4) the highest stress of 235.5 kV/cm is observed in ethylene glycol/water mixture with an ethylene glycol concentration of 80% at a hydrostatic pressure of 1215.9 kPa and is about one time greater than that in pure water at constant pressure; (5) for pressurization and surface pohshing,the primary mechanism to improve the breakdown strength of water dielectric is the increase in the breakdown time delay. Research results indicate great potential in the application of the high power pulse conditioning system of water dielectric.

  9. Emerging biomarkers in psoriatic arthritis.

    Science.gov (United States)

    Paek, So Yeon; Han, Ling; Weiland, Matthew; Lu, Chuan-Jian; McKinnon, Kathleen; Zhou, Li; Lim, Henry W; Elder, James T; Mi, Qing-Sheng

    2015-12-01

    Psoriasis is an immune-mediated skin disease which affects 2-4% of the worldwide population. Approximately 20-30% of patients with psoriasis develop psoriatic arthritis (PsA), a frequently destructive and disabling condition. As skin manifestations precede joint symptoms in nearly all patients with PsA, identification of biomarkers for early prediction of joint damage is an important clinical need. Because not all patients with PsA respond to treatment in the same fashion, identification of biomarkers capable of predicting therapeutic response is also imperative. Here, we review existing literature and discuss current investigations to identify potential biomarkers for PsA disease activity, with particular emphasis on microRNAs as novel markers of interest. Serum (soluble) biomarkers, peripheral osteoclast precursor as cellular biomarkers, and genetic loci associated with skin and joint disease are also reviewed. PMID:26602058

  10. Epigenetic biomarkers in liver cancer.

    Science.gov (United States)

    Banaudha, Krishna K; Verma, Mukesh

    2015-01-01

    Liver cancer (hepatocellular carcinoma or HCC) is a major cancer worldwide. Research in this field is needed to identify biomarkers that can be used for early detection of the disease as well as new approaches to its treatment. Epigenetic biomarkers provide an opportunity to understand liver cancer etiology and evaluate novel epigenetic inhibitors for treatment. Traditionally, liver cirrhosis, proteomic biomarkers, and the presence of hepatitis viruses have been used for the detection and diagnosis of liver cancer. Promising results from microRNA (miRNA) profiling and hypermethylation of selected genes have raised hopes of identifying new biomarkers. Some of these epigenetic biomarkers may be useful in risk assessment and for screening populations to identify who is likely to develop cancer. Challenges and opportunities in the field are discussed in this chapter.

  11. Work Breakdown Structures The Foundation for Project Management Excellence

    CERN Document Server

    Norman, Eric S; Fried, Robert T

    2011-01-01

    Understand and apply new concepts regarding Work Breakdown Structures The Work Breakdown Structure (WBS) has emerged as a foundational concept and tool in Project Management. It is an enabler that ensures clear definition and communication of project scope while performing a critical role as a monitoring and controlling tool. Created by the three experts who led the development of PMI's Practice Standard for Work Breakdown Structures, Second Edition, this much-needed text expands on what the standard covers and describes how to go about successfully implementing the WBS within the project life

  12. The statistics of the dielectric breakdown of thin films

    CERN Document Server

    Rowland, S M

    1984-01-01

    The statistics of the dielectric breakdown of thin films of silicon monoxide and aluminium oxide have been studied. The self healing technique which allows numerous breakdowns to be observed on one sample was employed. Ramp and steady state voltage experiments are reported and the limitations of these techniques are discussed. It is shown that the experimental data on breakdown can be fitted to two-parameter Weibull distributions using mixed distribution models. Methods have been developed to facilitate the evaluation of the associated parameters from results taken over limited time periods by graphical means. The significance of these parameters and the relationship between ramp and steady state testing techniques are discussed.

  13. An energy efficient breakdown cover service for electric cars

    OpenAIRE

    Cappelle, Jan; Vispoel, Stijn; Van Maerhem, Thomas

    2012-01-01

    A typical breakdown cover service unit in Belgium has to assist up to 5 cars a day that end up with an empty fuel tank. As the range of today’s battery electric cars is lower than what people are used to have today, breakdown cover services expect that massive introduction of electric cars will lead to a multiple of EVs ending up with an empty battery. This paper reports about a research project, initiated by a Belgian breakdown cover service, that aimed to design and build a prot...

  14. A STUDY OF HIGH POWER MICROWAVE AIR BREAKDOWN

    Institute of Scientific and Technical Information of China (English)

    LIU GUO-ZHI; LIU JING-YUE; HUANG WEN-HUA; ZHOU JIN-SHAN; SONG XIAO-XIN; NING HUI

    2000-01-01

    This paper presents the results of research on microwave breakdown in air, it includes the experimental study and the theoretical analysis. The experimental study has been done in a waveguide with a frequency of 9.37GHz, the peak power up to 200kW, pulse width from 0.3 to 2.0μs. The repetition rate of microwave source is from single pulse to 970 pulse per second. The process of the breakdown of repetition pulse has also been recorded for a burst of ten pulses. A theoretical model for breakdown threshold is presented also. The theoretical are in good agreement with the experimental ones.

  15. Breakdown voltage analysis of field limiting ring structure

    International Nuclear Information System (INIS)

    In this paper, a computer based analysis is performed to study the effect of floating field-limiting rings (FLR) on the breakdown voltage of Si microstrip detectors. For optimum performance it is crucial to achieve the maximum breakdown voltage for Si detectors operated at very high bias due to extremely hostile radiation environment of LHC. The breakdown performance of Si microstrip detectors can be improved by implementing floating field-limiting rings (FLR) around the active detector area. In the present work, we propose a criterion for optimising the spacing of FLR with respect to the main junction. (author)

  16. Avalanche breakdown of the quantum hall effects

    CERN Document Server

    Komiyama, S

    1999-01-01

    Heat stability of two-dimensional electron gas (2DEG) systems in the integer quantum hall effect (IQHE) regime is discussed, and a heat instability is suggested to be the intrinsic mechanism behind the breakdown of the IQHE. Phenomenological argument is provided to suggest that the 2DEG system in the IQHE state becomes thermally unstable when the Hall electric field E sub y reaches a threshold value E sub b. Above E sub b , excited nonequilibrium electrons (holes), which are initially present in the conductor as the temperature fluctuation, are accelerated by E sub y and the 2DEG thereby undergoes a transition to a warm dissipative state. The critical field, E sub b , of this abrupt transition is theoretically estimated and shown to be in fare agreement with experimentally reported values. Consideration of the dynamics of electrons suggests that the transition is a process of avalanche electron-hole pair multiplication, in which a small number of non-equilibrium carriers, gains kinetic energy within a Landau ...

  17. Modeling of a breakdown voltage in microdischarges

    Directory of Open Access Journals (Sweden)

    Đorđević Ivana

    2009-01-01

    Full Text Available Non-equilibrium plasmas have been used as one of the principal technologies for development of microelectronics and they are the basis for the development of new generations of nano-electronics devices required for 65 and 40 nm technologies. Microdischarges recently have become more common in everyday life. Technology of plasma etching has enabled us to develop such discharges and the field of microdischarges has grown into the most interesting field of the physics of collisional non-equilibrium plasmas. Recently, an effort to fabricate microplasma sources that can be integrated with other MEMS devices to form larger Microsystems has been made. Plasma-based microsystems can find application in bio-microelectro- mechanical system (bio-MEMS sterilization, small-scale materials processing and microchemical analysis systems. However, integrability requires not only a size reduction, but also an understanding of the physics governing the new small-scale discharges. In this paper, we have performed modeling of a breakdown voltage by using Particle-in-Cell/Monte Carlo collision (PIC/MCC code taking into account the secondary electron emission due to a high field.

  18. Novel laser breakdown spectrometer for environmental monitoring

    Science.gov (United States)

    Mirov, Sergey B.; Pitt, Robert E.; Dergachev, Alex Y.; Lee, Wonwoo; Martyshkin, Dmitri V.; Mirov, Olga D.; Randolph, Jeremy J.; DeLucas, Lawrence J.; Brouillette, Christie G.; Basiev, Tasoltan T.; Orlovskii, Yurii V.; Alimov, Olimkhon K.; Vorob'ev, Ivan N.

    1999-11-01

    A novel experimental set-up using laser-induced breakdown spectroscopy (LIBS) for environmental analyses of heavy metals is described in this paper. It is based on state-of-the-art spectroscopic equipment, advanced detectors, and laser atomizers: a 0.75 m spectrometer ARC-750, intensified TE- cooled 256 X 1024 CCD camera, probe with fiber optic guide for signal transportation, and Nd:YAG laser plasma atomizers with two different methods for sample delivery. In the first method the liquid solution containing the atoms to be investigated is drawn into the chamber of the nebulizer. The mixture passes through the nozzle, accompanied by argon gas along with formed aerosol, and enters the plasma plume, which is generated by the laser spark in argon. The second method is based on direct generating of the plasma in the water jet of a continuously circulating sample. LIBS testing of samples containing Al, Cd, Cu, Fe, Pb, Zn, and Cr ions was compared with results using atomic absorption spectrophotometry. Initial indications showed good agreement between these two methods. Detection levels of less than 100 ppb were observed for copper and chromium. The described spectroscopic system exhibits high sensitivity, accumulation of luminescence spectrum in real time; and high dynamic range for concentrations detection from 100 ppb to 1000 ppm.

  19. Medical Applications of Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail

  20. Investigation of laser induced breakdown in liquid nitromethane using nanosecond shadowgraphy

    Science.gov (United States)

    Guo, Wencan; Zheng, Xianxu; Yu, Guoyang; Zhao, Jun; Zeng, Yangyang; Liu, Cangli

    2016-09-01

    A nanosecond time-resolved shadowgraphy is performed to observe a laser-induced breakdown in nitromethane. The digital delays are introduced between a pump beam and an illumination light to achieve a measuring range from 40 ns to 100 ms, which enable us to study the shock wave propagation, bubble dynamics, and other process of the laser-induced breakdown. Compared with distilled water, there are two obvious differences observed in nitromethane: (1) the production of a non-evaporative gas at the final stage, and (2) an absence of the secondary shock wave after the first collapse of the bubble. We also calculated the bubble energy in nitromethane and distilled water under a different incident energy. The results indicate that the bubble energy in nitromethane is more than twice as large as that in water. It is suggested that chemical reactions contribute to the releasing of energy.

  1. The Influence of the Magnetic Field on the Electrical Breakdown Phenomena

    Institute of Scientific and Technical Information of China (English)

    M.RADMILOVI(C)-RADJENOVI(C); B.RADJNOVI(C)

    2007-01-01

    A simple phenomenological model and detailed simulation studies of the breakdown phenomena in argon and nitrogen under the simultaneous action of electric and magnetic fields are presented in this paper. Expressions for the breakdown voltage have been derived taking into account variations of both the ionization coefficient and the secondary electron yield in a magnetic field. Calculations were performed by using XOOPIC code, an Object Oriented Particle in Cell code, with both the original and the improved secondary emission model with inclusion of the influence of the magnetic field on the secondary electron production. The simulation results presented here clearly show that the inclusion of the dependence of the secondary electron yield on the magnetic field leads to better agreement with existing experimental results.

  2. Biomarkers for lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Zangar, Richard C.; Varnum, Susan M.

    2014-09-02

    A biomarker, method, test kit, and diagnostic system for detecting the presence of lymphoma in a person are disclosed. The lymphoma may be Hodgkin's lymphoma or non-Hodgkin's lymphoma. The person may be a high-risk subject. In one embodiment, a plasma sample from a person is obtained. The level of at least one protein listed in Table S3 in the plasma sample is measured. The level of at least one protein in the plasma sample is compared with the level in a normal or healthy subject. The lymphoma is diagnosed based upon the level of the at least one protein in the plasma sample in comparison to the normal or healthy level.

  3. Biomarkers of manganese intoxication.

    Science.gov (United States)

    Zheng, Wei; Fu, Sherleen X; Dydak, Ulrike; Cowan, Dallas M

    2011-01-01

    Manganese (Mn), upon absorption, is primarily sequestered in tissue and intracellular compartments. For this reason, blood Mn concentration does not always accurately reflect Mn concentration in the targeted tissue, particularly in the brain. The discrepancy between Mn concentrations in tissue or intracellular components means that blood Mn is a poor biomarker of Mn exposure or toxicity under many conditions and that other biomarkers must be established. For group comparisons of active workers, blood Mn has some utility for distinguishing exposed from unexposed subjects, although the large variability in mean values renders it insensitive for discriminating one individual from the rest of the study population. Mn exposure is known to alter iron (Fe) homeostasis. The Mn/Fe ratio (MIR) in plasma or erythrocytes reflects not only steady-state concentrations of Mn or Fe in tested individuals, but also a biological response (altered Fe homeostasis) to Mn exposure. Recent human studies support the potential value for using MIR to distinguish individuals with Mn exposure. Additionally, magnetic resonance imaging (MRI), in combination with noninvasive assessment of γ-aminobutyric acid (GABA) by magnetic resonance spectroscopy (MRS), provides convincing evidence of Mn exposure, even without clinical symptoms of Mn intoxication. For subjects with long-term, low-dose Mn exposure or for those exposed in the past but not the present, neither blood Mn nor MRI provides a confident distinction for Mn exposure or intoxication. While plasma or erythrocyte MIR is more likely a sensitive measure, the cut-off values for MIR among the general population need to be further tested and established. Considering the large accumulation of Mn in bone, developing an X-ray fluorescence spectroscopy or neutron-based spectroscopy method may create yet another novel non-invasive tool for assessing Mn exposure and toxicity. PMID:20946915

  4. Optimal Rules for Single Machine Scheduling with Stochastic Breakdowns

    Directory of Open Access Journals (Sweden)

    Jinwei Gu

    2014-01-01

    Full Text Available This paper studies the problem of scheduling a set of jobs on a single machine subject to stochastic breakdowns, where jobs have to be restarted if preemptions occur because of breakdowns. The breakdown process of the machine is independent of the jobs processed on the machine. The processing times required to complete the jobs are constants if no breakdown occurs. The machine uptimes are independently and identically distributed (i.i.d. and are subject to a uniform distribution. It is proved that the Longest Processing Time first (LPT rule minimizes the expected makespan. For the large-scale problem, it is also showed that the Shortest Processing Time first (SPT rule is optimal to minimize the expected total completion times of all jobs.

  5. Breakdown analysis for electrodeless discharge in a magnetic field

    International Nuclear Information System (INIS)

    A fluid model for an electrode-less, toroidal breakdown process in presence of a steady magnetic field is developed. Breakdown processes in the Extrap configuration are studied. Both particle balance and energy balance are solved to obtain breakdown voltages. A 2-dimensional particle balance is solved for the Extrap configuration, and the existence of the magnetic nulls seems to play an important role. The concept of the Townsend first coefficient α is found not to be applicable when the particle losses are severe, and the energy balance has to be solved in order to explain the very high low-threshold of the filling pressure observed in the Extrap breakdown experiments. The theoretical results are compared with experiments; a fairly good agreement is achieved. (author)

  6. Action of space charge on aging and breakdown of polymers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The study on how space charges affect aging and breakdown of polymers becomes one of the most important domains. Most of the models are based on the injected charges increasing the local field to induce the breakdown of polymers and breaking the large molecule chains. These models ignore the effects of space charge on the microstruc-ture of dielectric materials. In this review, with the calcula-tion of the electromagnetic energy and the electromechanical energy around a trapped charge and with some new experi-mental results, it is proved that aging and breakdown in polymers are caused during the detrapping of the trapped charges. Aging and breakdown of the polymers are related to the release of the electromechanical energy around trapped charges.

  7. Surface of Alumina Films after Prolonged Breakdowns in Galvanostatic Anodization

    Directory of Open Access Journals (Sweden)

    Christian Girginov

    2011-01-01

    Full Text Available Breakdown phenomena are investigated at continuous isothermal (20∘C and galvanostatic (0.2–5 mA cm−2 anodizing of aluminum in ammonium salicylate in dimethylformamide (1 M AS/DMF electrolyte. From the kinetic (-curves, the breakdown voltage ( values are estimated, as well as the frequency and amplitude of oscillations of formation voltage ( at different current densities. The surface of the aluminum specimens was studied using atomic force microscopy (AFM. Data on topography and surface roughness parameters of the electrode after electric breakdowns are obtained as a function of anodization time. The electrode surface of anodic films, formed with different current densities until the same charge density has passed (2.5 C cm−2, was assessed. Results are discussed on the basis of perceptions of avalanche mechanism of the breakdown phenomena, due to the injection of electrons and their multiplication in the volume of the film.

  8. Priliminary Modeling of Air Breakdown with the ICEPIC code

    CERN Document Server

    Schulz, A E; Cartwright, K L; Mardahl, P J; Peterkin, R E; Bruner, N; Genoni, T; Hughes, T P; Welch, D

    2004-01-01

    Interest in air breakdown phenomena has recently been re-kindled with the advent of advanced virtual prototyping of radio frequency (RF) sources for use in high power microwave (HPM) weapons technology. Air breakdown phenomena are of interest because the formation of a plasma layer at the aperture of an RF source decreases the transmitted power to the target, and in some cases can cause significant reflection of RF radiation. Understanding the mechanisms behind the formation of such plasma layers will aid in the development of maximally effective sources. This paper begins with some of the basic theory behind air breakdown, and describes two independent approaches to modeling the formation of plasmas, the dielectric fluid model and the Particle in Cell (PIC) approach. Finally we present the results of preliminary studies in numerical modeling and simulation of breakdown.

  9. Vortex breakdown in closed containers with polygonal cross sections

    International Nuclear Information System (INIS)

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results

  10. Breakdown in Breathing: The Complexities of Cystic Fibrosis

    Science.gov (United States)

    ... Subscribe A Breakdown in Breathing The Complexities of Cystic Fibrosis Cystic fibrosis (CF) is an inherited illness that ravages the ... B. Guggino, a researcher with the Johns Hopkins Cystic Fibrosis Center. But in CF, “the mucus gets sticky, ...

  11. Compact High Sensitive Laser-Induced Breakdown Spectroscopy Instrument Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser induced breakdown spectroscopy (LIBS) is a versatile tool for in situ substance characterization. Existing LIBS instruments are not compact enough for space...

  12. INCREASING BREAKDOWN VOLTAGE OF LDMOST USING BURIED LAYER

    Institute of Scientific and Technical Information of China (English)

    Han Lei; Ye Xingning; Chen Xingbi

    2003-01-01

    A new LDMOST structure, named B-LDMOST that has a buried layer under the drain is proposed. The buried layer is not connected to the drift region, so it can optimize the vertical field distribution and increase breakdown voltage. The analysis and the simulated results show that B-LDMOST can increase breakdown voltage, with almost negligible influence on the other parameters such as on-resistance, switching time, and so on.

  13. INCREASING BREAKDOWN VOLTAGE OF LDMOST USING BURIED LAYER

    Institute of Scientific and Technical Information of China (English)

    HanLei; YeXingning; 等

    2003-01-01

    A new LDMOST structure,named B-LDMOST that has a buried layer under the drain is proposed.The buried layer is not connected to the drift region,so it can optimize the vertical field distribution and increase breakdown voltage.The analysis and the simulated results show that B-LDMOST can increase breakdown voltage,with almost negligible influence on the other parameters such as on-resistance,switching time,and so om.

  14. Enhancement of dielectric breakdown strengths in polymer film capacitors

    International Nuclear Information System (INIS)

    This paper reports that breakdown voltages of wound, polymer film/metal foil capacitors have been dramatically increased by briefly exposing them (after they had been spirally wound) to a low pressure, low temperature gas plasma. Exposure of wound, polycarbonate-based capacitors to a 96%CF4/4%O2 gas plasma for 4 minutes, for example, produced a 200% increase in breakdown voltage

  15. Ionizing potential waves and high-voltage breakdown streamers.

    Science.gov (United States)

    Albright, N. W.; Tidman, D. A.

    1972-01-01

    The structure of ionizing potential waves driven by a strong electric field in a dense gas is discussed. Negative breakdown waves are found to propagate with a velocity proportional to the electric field normal to the wavefront. This causes a curved ionizing potential wavefront to focus down into a filamentary structure, and may provide the reason why breakdown in dense gases propagates in the form of a narrow leader streamer instead of a broad wavefront.

  16. Slag analysis with laser-induced breakdown spectrometry.

    Science.gov (United States)

    Kraushaar, M; Noll, R; Schmitz, H U

    2003-10-01

    Laser-induced breakdown spectrometry (LIBS) has been applied for multi-elemental analysis of slag samples from a steel plant. In order to avoid the time-consuming step of sample preparation, the liquid slag material can be filled in special probes. After cooling of the liquid slag and solidification, the samples can be analyzed with LIBS. Chemical analysis of slag is an essential input parameter used for numerical simulations to control liquid steel processing. The relative variation range of element concentrations in slag samples from steel production can amount to up to 30%. A multivariate calibration model is used to take into account matrix effects caused by these varying concentrations. By optimizing the measuring parameters as well as the calibration models, an agreement between the standard X-ray fluorescence (XRF) analysis and LIBS analysis in terms of the coefficient of determination r2 of 0.99 for the main analytes CaO, SiO2, and Fetot of converter slag samples was achieved. The average repeatability of the LIBS measurement for these elements in terms of the relative standard deviation of the determined concentration is improved to less than 1.0%. With these results, the basis is established for future on-line applications of LIBS in the steel-making industry for slag analysis. PMID:14639759

  17. Communication and pragmatic breakdowns in amyotrophic lateral sclerosis patients.

    Science.gov (United States)

    Bambini, Valentina; Arcara, Giorgio; Martinelli, Ilaria; Bernini, Sara; Alvisi, Elena; Moro, Andrea; Cappa, Stefano F; Ceroni, Mauro

    2016-02-01

    While there is increasing attention toward cognitive changes in amyotrophic lateral sclerosis (ALS), the domain of pragmatics, defined as the ability to integrate language and context to engage in successful communication, remains unexplored. Here we tested pragmatic abilities in 33 non-demented ALS patients and 33 healthy controls matched for age and education through 6 different tasks, ranging from discourse organization to the comprehension of figurative language, further grouped in three composite measures for pragmatic production, pragmatic comprehension and global pragmatic abilities. For a subgroup of patients, assessment included executive functions and social cognition skills. ALS patients were impaired on all pragmatic tasks relative to controls, with 45% of the patients performing below cut-off in at least one pragmatic task, and 36% impaired on the global pragmatic score. Pragmatic breakdowns were more common than executive deficit as defined by the consensus criteria, and approximately as prevalent as deficits in social cognition. Multiple regression analyses support the idea of an interplay of executive and social cognition abilities in determining the pragmatic performance, although all these domains show some degree of independence. These findings shed light on pragmatic impairment as a relevant dimension of ALS, which deserves further consideration in defining the cognitive profile of the disease, given its vital role for communication and social interaction in daily life.

  18. Saccharide breakdown and fermentation by the honey bee gut microbiome.

    Science.gov (United States)

    Lee, Fredrick J; Rusch, Douglas B; Stewart, Frank J; Mattila, Heather R; Newton, Irene L G

    2015-03-01

    The honey bee, the world's most important agricultural pollinator, relies exclusively on plant-derived foods for nutrition. Nectar and pollen collected by honey bees are processed and matured within the nest through the activities of honey bee-derived microbes and enzymes. In order to better understand the contribution of the microbial community to food processing in the honey bee, we generated a metatranscriptome of the honey bee gut microbiome. The function of the microbial community in the honey bee, as revealed by metatranscriptome sequencing, resembles that of other animal guts and food-processing environments. We identified three major bacterial classes that are active in the gut (γ-Proteobacteria, Bacilli and Actinobacteria), all of which are predicted to participate in the breakdown of complex macromolecules (e.g. polysaccharides and polypeptides), the fermentation of component parts of these macromolecules, and the generation of various fermentation products, such as short-chain fatty acids and alcohol. The ability of the microbial community to metabolize these carbon-rich food sources was confirmed through the use of community-level physiological profiling. Collectively, these findings suggest that the gut microflora of the honey bee harbours bacterial members with unique roles, which ultimately can contribute to the processing of plant-derived food for colonies. PMID:24905222

  19. Saccharide breakdown and fermentation by the honey bee gut microbiome.

    Science.gov (United States)

    Lee, Fredrick J; Rusch, Douglas B; Stewart, Frank J; Mattila, Heather R; Newton, Irene L G

    2015-03-01

    The honey bee, the world's most important agricultural pollinator, relies exclusively on plant-derived foods for nutrition. Nectar and pollen collected by honey bees are processed and matured within the nest through the activities of honey bee-derived microbes and enzymes. In order to better understand the contribution of the microbial community to food processing in the honey bee, we generated a metatranscriptome of the honey bee gut microbiome. The function of the microbial community in the honey bee, as revealed by metatranscriptome sequencing, resembles that of other animal guts and food-processing environments. We identified three major bacterial classes that are active in the gut (γ-Proteobacteria, Bacilli and Actinobacteria), all of which are predicted to participate in the breakdown of complex macromolecules (e.g. polysaccharides and polypeptides), the fermentation of component parts of these macromolecules, and the generation of various fermentation products, such as short-chain fatty acids and alcohol. The ability of the microbial community to metabolize these carbon-rich food sources was confirmed through the use of community-level physiological profiling. Collectively, these findings suggest that the gut microflora of the honey bee harbours bacterial members with unique roles, which ultimately can contribute to the processing of plant-derived food for colonies.

  20. Novel technologies and emerging biomarkers for personalized cancer immunotherapy.

    Science.gov (United States)

    Yuan, Jianda; Hegde, Priti S; Clynes, Raphael; Foukas, Periklis G; Harari, Alexandre; Kleen, Thomas O; Kvistborg, Pia; Maccalli, Cristina; Maecker, Holden T; Page, David B; Robins, Harlan; Song, Wenru; Stack, Edward C; Wang, Ena; Whiteside, Theresa L; Zhao, Yingdong; Zwierzina, Heinz; Butterfield, Lisa H; Fox, Bernard A

    2016-01-01

    The culmination of over a century's work to understand the role of the immune system in tumor control has led to the recent advances in cancer immunotherapies that have resulted in durable clinical responses in patients with a variety of malignancies. Cancer immunotherapies are rapidly changing traditional treatment paradigms and expanding the therapeutic landscape for cancer patients. However, despite the current success of these therapies, not all patients respond to immunotherapy and even those that do often experience toxicities. Thus, there is a growing need to identify predictive and prognostic biomarkers that enhance our understanding of the mechanisms underlying the complex interactions between the immune system and cancer. Therefore, the Society for Immunotherapy of Cancer (SITC) reconvened an Immune Biomarkers Task Force to review state of the art technologies, identify current hurdlers, and make recommendations for the field. As a product of this task force, Working Group 2 (WG2), consisting of international experts from academia and industry, assembled to identify and discuss promising technologies for biomarker discovery and validation. Thus, this WG2 consensus paper will focus on the current status of emerging biomarkers for immune checkpoint blockade therapy and discuss novel technologies as well as high dimensional data analysis platforms that will be pivotal for future biomarker research. In addition, this paper will include a brief overview of the current challenges with recommendations for future biomarker discovery.

  1. Fibrosis biomarkers in workers exposed to MWCNTs.

    Science.gov (United States)

    Fatkhutdinova, Liliya M; Khaliullin, Timur O; Vasil'yeva, Olga L; Zalyalov, Ramil R; Mustafin, Ilshat G; Kisin, Elena R; Birch, M Eileen; Yanamala, Naveena; Shvedova, Anna A

    2016-05-15

    Multi-walled carbon nanotubes (MWCNT) with their unique physico-chemical properties offer numerous technological advantages and are projected to drive the next generation of manufacturing growth. As MWCNT have already found utility in different industries including construction, engineering, energy production, space exploration and biomedicine, large quantities of MWCNT may reach the environment and inadvertently lead to human exposure. This necessitates the urgent assessment of their potential health effects in humans. The current study was carried out at NanotechCenter Ltd. Enterprise (Tambov, Russia) where large-scale manufacturing of MWCNT along with relatively high occupational exposure levels was reported. The goal of this small cross-sectional study was to evaluate potential biomarkers during occupational exposure to MWCNT. All air samples were collected at the workplaces from both specific areas and personal breathing zones using filter-based devices to quantitate elemental carbon and perform particle analysis by TEM. Biological fluids of nasal lavage, induced sputum and blood serum were obtained from MWCNT-exposed and non-exposed workers for assessment of inflammatory and fibrotic markers. It was found that exposure to MWCNTs caused significant increase in IL-1β, IL6, TNF-α, inflammatory cytokines and KL-6, a serological biomarker for interstitial lung disease in collected sputum samples. Moreover, the level of TGF-β1 was increased in serum obtained from young exposed workers. Overall, the results from this study revealed accumulation of inflammatory and fibrotic biomarkers in biofluids of workers manufacturing MWCNTs. Therefore, the biomarkers analyzed should be considered for the assessment of health effects of occupational exposure to MWCNT in cross-sectional epidemiological studies. PMID:26902652

  2. On the assessment of extremely low breakdown probabilities by an inverse sampling procedure [gaseous insulation

    DEFF Research Database (Denmark)

    Thyregod, Poul; Vibholm, Svend

    1991-01-01

    a breakdown occurs. Following a breakdown, the procedure is restarted at the initial level. The procedure is repeated until a predetermined number of breakdowns have occurred, and the average and standard deviation of the observed first breakdown levels are recorded. The authors derive the relation between...

  3. Biomarker in archaeological soils

    Science.gov (United States)

    Wiedner, Katja; Glaser, Bruno; Schneeweiß, Jens

    2015-04-01

    The use of biomarkers in an archaeological context allow deeper insights into the understanding of anthropogenic (dark) earth formation and from an archaeological point of view, a completely new perspective on cultivation practices in the historic past. During an archaeological excavation of a Slavic settlement (10th/11th C. A.D.) in Brünkendorf (Wendland region in Northern Germany), a thick black soil (Nordic Dark Earth) was discovered that resembled the famous terra preta phenomenon. For the humid tropics, terra preta could act as model for sustainable agricultural practices and as example for long-term CO2-sequestration into terrestrial ecosystems. The question was whether this Nordic Dark Earth had similar properties and genesis as the famous Amazonian Dark Earth in order to find a model for sustainable agricultural practices and long term CO2-sequestration in temperate zones. For this purpose, a multi-analytical approach was used to characterize the sandy-textured Nordic Dark Earth in comparison to less anthropogenically influenced soils in the adjacent area in respect of ecological conditions (e.g. amino sugar), input materials (faeces) and the presence of stable soil organic matter (black carbon). Amino sugar analyses showed that Nordic Dark Earth contained higher amounts of microbial residues being dominated by soil fungi. Faecal biomarkers such as stanols and bile acids indicated animal manure from omnivores and herbivores but also human excrements. Black carbon content of about 30 Mg ha-1 in the Nordic Dark Earth was about four times higher compared to the adjacent soil and in the same order of magnitude compared to terra preta. Our data strongly suggest parallels to anthropogenic soil formation in Amazonia and in Europe by input of organic wastes, faecal material and charred organic matter. An obvious difference was that in terra preta input of human-derived faecal material dominated while in NDE human-derived faecal material played only a minor role

  4. Urinary Biomarkers of Brain Diseases

    Directory of Open Access Journals (Sweden)

    Manxia An

    2015-12-01

    Full Text Available Biomarkers are the measurable changes associated with a physiological or pathophysiological process. Unlike blood, urine is not subject to homeostatic mechanisms. Therefore, greater fluctuations could occur in urine than in blood, better reflecting the changes in human body. The roadmap of urine biomarker era was proposed. Although urine analysis has been attempted for clinical diagnosis, and urine has been monitored during the progression of many diseases, particularly urinary system diseases, whether urine can reflect brain disease status remains uncertain. As some biomarkers of brain diseases can be detected in the body fluids such as cerebrospinal fluid and blood, there is a possibility that urine also contain biomarkers of brain diseases. This review summarizes the clues of brain diseases reflected in the urine proteome and metabolome.

  5. Biomarkers of latent TB infection

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Ravn, Pernille

    2009-01-01

    For the last 100 years, the tuberculin skin test (TST) has been the only diagnostic tool available for latent TB infection (LTBI) and no biomarker per se is available to diagnose the presence of LTBI. With the introduction of M. tuberculosis-specific IFN-gamma release assays (IGRAs), a new area of...... in vitro immunodiagnostic tests for LTBI based on biomarker readout has become a reality. In this review, we discuss existing evidence on the clinical usefulness of IGRAs and the indefinite number of potential new biomarkers that can be used to improve diagnosis of latent TB infection. We also...... present early data suggesting that the monocyte-derived chemokine inducible protein-10 may be useful as a novel biomarker for the immunodiagnosis of latent TB infection....

  6. Cardiac Biomarkers and Cycling Race

    OpenAIRE

    Caroline Le Goff, Jean-François Kaux, Sébastien Goffaux, Etienne Cavalier

    2015-01-01

    In cycling as in other types of strenuous exercise, there exists a risk of sudden death. It is important both to understand its causes and to see if the behavior of certain biomarkers might highlight athletes at risk. Many reports describe changes in biomarkers after strenuous exercise (Nie et al., 2011), but interpreting these changes, and notably distinguishing normal physiological responses from pathological changes, is not easy. Here we have focused on the kinetics of different cardiac bi...

  7. Biomarkers in Acute Lung Injury

    OpenAIRE

    Bhargava, Maneesh; Wendt, Chris

    2012-01-01

    Acute Respiratory Distress Syndrome (ARDS) and Acute Lung Injury (ALI) result in high permeability pulmonary edema causing hypoxic respiratory failure with high morbidity and mortality. As the population ages, the incidence of ALI is expected to rise. Over the last decade, several studies have identified biomarkers in plasma and bronchoalveolar lavage fluid providing important insights into the mechanisms involved in the pathophysiology of ALI. Several biomarkers have been validated in subjec...

  8. Biomarkers in Prostate Cancer Epidemiology

    OpenAIRE

    Mudit Verma; Mukesh Verma; Payal Patel

    2011-01-01

    Understanding the etiology of a disease such as prostate cancer may help in identifying populations at high risk, timely intervention of the disease, and proper treatment. Biomarkers, along with exposure history and clinical data, are useful tools to achieve these goals. Individual risk and population incidence of prostate cancer result from the intervention of genetic susceptibility and exposure. Biochemical, epigenetic, genetic, and imaging biomarkers are used to identify people at high ris...

  9. Analysis of biomarker data a practical guide

    CERN Document Server

    Looney, Stephen W

    2015-01-01

    A "how to" guide for applying statistical methods to biomarker data analysis Presenting a solid foundation for the statistical methods that are used to analyze biomarker data, Analysis of Biomarker Data: A Practical Guide features preferred techniques for biomarker validation. The authors provide descriptions of select elementary statistical methods that are traditionally used to analyze biomarker data with a focus on the proper application of each method, including necessary assumptions, software recommendations, and proper interpretation of computer output. In addition, the book discusses

  10. Neuroimmune biomarkers in schizophrenia.

    Science.gov (United States)

    Tomasik, Jakub; Rahmoune, Hassan; Guest, Paul C; Bahn, Sabine

    2016-09-01

    Schizophrenia is a heterogeneous psychiatric disorder with a broad spectrum of clinical and biological manifestations. Due to the lack of objective tests, the accurate diagnosis and selection of effective treatments for schizophrenia remains challenging. Numerous technologies have been employed in search of schizophrenia biomarkers. These studies have suggested that neuroinflammatory processes may play a role in schizophrenia pathogenesis, at least in a subgroup of patients. The evidence indicates alterations in both pro- and anti-inflammatory molecules in the central nervous system, which have also been found in peripheral tissues and may correlate with schizophrenia symptoms. In line with these findings, certain immunomodulatory interventions have shown beneficial effects on psychotic symptoms in schizophrenia patients, in particular those with distinct immune signatures. In this review, we evaluate these findings and their potential for more targeted drug interventions and the development of companion diagnostics. Although currently no validated markers exist for schizophrenia patient stratification or the prediction of treatment efficacy, we propose that utilisation of inflammatory markers for diagnostic and theranostic purposes may lead to novel therapeutic approaches and deliver more effective care for schizophrenia patients. PMID:25124519

  11. Analysis of breakdown on thermal and electrical measurements for SPIDER accelerating grids

    Energy Technology Data Exchange (ETDEWEB)

    Pesce, Alberto, E-mail: alberto.pesce@igi.cnr.it [Consorzio RFX - Associazione EURATOM-ENEA per la fusione, Corso Stati Uniti 4, 35127 Padova (Italy); Pomaro, Nicola [Consorzio RFX - Associazione EURATOM-ENEA per la fusione, Corso Stati Uniti 4, 35127 Padova (Italy)

    2011-10-15

    The PRIMA test facility, under realization in Padova, includes a full size plasma source prototype for ITER, called SPIDER (Source for the Production of Ions of Deuterium Extracted from Radio Frequency plasma). The effects of breakdown in the electrical insulation inside the ion source are analyzed with particular care to the embedded diagnostic system, i.e. the thermal and electrical measurements installed on the grids and ion source case and transferred by multipolar cables to the acquisition system, located inside the 100 kV insulated deck and hosting the ion source power supply, the signal conditioning and the acquisition cubicles. The breakdown affects strongly the measurements, so it has to be mitigated in order to guarantee adequate reliability of the whole measurement set. A parametric study has been carried out on a detailed circuital model for fast transients, implemented using SimPowerSystems{sup TM} tool of Matlab Simulink code. The model includes all the relevant conductors of the subsystems downstream the insulating transformer of the Accelerating Grids Power Supply (AGPS), i.e. the AGPS rectifier, the multipolar transmission line, the 100 kV High Voltage Deck, the ion source power supply and the ion source itself. In particular all the magnetic and capacitive couplings have been computed by a proper 2D fem model. The optimization of the cabling layout, of the wire screening and of the protection devices, like surge arresters and resistors, has been carried out through the accurate modeling of the circuit. The energy dissipated on each ion source surge arrester is estimated and adequate TSD (transient suppression devices) are selected. A peculiar and difficult to satisfy requirement is the high number of surges that the TSD has to withstand. Breakdowns between components polarized at different voltages have been considered, in order to inspect the worst condition during a breakdown.

  12. Avalanche electron bunching in a Corbino disk in the quantum Hall effect breakdown regime

    Science.gov (United States)

    Chida, Kensaku; Hata, Tokuro; Arakawa, Tomonori; Matsuo, Sadashige; Nishihara, Yoshitaka; Tanaka, Takahiro; Ono, Teruo; Kobayashi, Kensuke

    2014-06-01

    We have measured the current noise in a device with Corbino geometry to investigate the dynamics of electrons in the breakdown regime of the integer quantum Hall effect (QHE). In the breakdown regime, the Fano factor of the current noise exceeds 103, which indicates the presence of electron bunching. As super-Poissonian current noise is observed only in the breakdown regime, the bunching effect is related to the QHE breakdown. These observations support a QHE breakdown mechanism that involves an electron avalanche.

  13. Biomarkers in the pathogenesis, diagnosis, and treatment of psoriasis

    Directory of Open Access Journals (Sweden)

    Molteni S

    2012-09-01

    Full Text Available Silvia Molteni, Eva RealiLaboratory of Translational Immunology, Istituto Ortopedico Galeazzi, Milan, ItalyAbstract: Development of psoriasis results from a complex interplay between genetically predisposing factors and environmental triggers that give rise to a self-sustaining pathogenic cycle involving T cells, dendritic cells, connective tissue, and skin epithelium. From 5% to 40% of patients with psoriasis also develop psoriatic arthritis, and increasing evidence indicates an association with other systemic manifestations, including cardiovascular disease and the metabolic syndrome. In psoriatic disease, there is a need for development of biomarkers for assessment of disease severity, for prediction of the outcome of therapeutic interventions, and for distinction between the different clinical variants of the disease. A field of great importance is identification of biomarkers for prediction of development of comorbidities, such as arthritis, cardiovascular disease, and the metabolic syndrome. Genetic determinants of psoriasis and their products not only give an important insight into the pathogenesis of the disease, but may also function as markers of risk for developing cutaneous psoriasis or psoriatic arthritis. So far, there are limited validation data to support the use of candidate biomarkers in clinical practice. Here we review the data from several studies on some of the most promising candidate biomarkers for cutaneous psoriasis and psoriatic arthritis, for the detection of systemic inflammation, and for use as endpoints for therapeutic interventions. Attention is focused on the molecules that take part in the interplay giving rise to psoriasis and on gene products that may represent a link between predisposing genetic factors and the immune and inflammatory processes involved in pathogenesis of the disease. Finally, we provide an overview on how biomarkers can offer insights into the pathogenesis and natural history of psoriasis

  14. 生物标志物在创伤性颅脑损伤中的应用%Application of biomarkers in traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    于芸; 韩如泉

    2013-01-01

    背景 创伤性颅脑损伤(traumatic brain injury,TBI)是青壮年致死致残的主要原因之一,生物标志物可定量评估脑损伤程度、预测疾病转归. 目的 探讨各种标志物用于评估脑损伤程度及转归的机制、研究现状及临床应用前景. 内容 综述脑外伤后神经元损伤标志物[神经元特异性烯醇化酶(neuron specific enolase,NSE)]、泛素C末端水解酶L1 (ubiquitin cterminal hydrolase-L1,UCH-L1)、Tau蛋白、胶质细胞损伤标志物(胶质细胞纤维酸性蛋白、S100)、炎性标志物[白细胞介素(interleukin,IL)-1、IL-6、IL-10、IL-8、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)]以及其他标志物(髓鞘碱性蛋白、膜收缩蛋白及其降解产物)的时程特点、评估损伤程度及预测转归的敏感性和特异性. 趋向 生物标志物辅助诊断TBI、预测神经系统转归、监测继发性损伤的临床应用价值有待进一步研究.%Background Traumatic brain injury (TBI) is the leading cause of death and disability among young adults.Biomarkers can be used to evaluate the severity of brain injury quantitatively and predict neurological outcome.Objective To discuss the mechanisms,current research status and clinical application prospects of biomarkers in assessing the degree of injury and predicting outcomes of TBI.Content In this review,the available data from biomarkers of TBI including neuron specific biomarkers (neuron specific enolase,ubiquitin C-terminal hydrolase-L1 and Tau protein),glial cell specific biomarkers (glial fibrillary acidic protein and S100),inflammatory biomarkers (IL-1,IL-6,IL-10,IL-8,TNF-α) and others (mylin basic protein,spectrin and its breakdown products) was overviewed.Time course,sensitivity and specificity of the above biomarkers were discussed.Trend The candidate biomarkers can be applied to aid the diagnosis of TBI,predict neurological outcomes and monitor secondary injury.However,the clinical utility needs to be further

  15. Study of the breakdown voltage of SiPMs

    CERN Document Server

    Chmill, V; Klanner, R; Nitschke, M; Schwandt, J

    2016-01-01

    The breakdown behaviour of SiPMs (Silicon PhotoMultiplier) with pixel sizes of 15$\\times $15, 25$\\times $25, 50$\\times $50, and 100$\\times $100 $\\mu $m$^2$, manufactured by KETEK, has been investigated. From the current-voltage characteristics measured with and without illumination by LED light of 470 nm wavelength, the current-breakdown voltage, $V_I$, and from linear fits of the voltage dependence of the SiPM gain, measured by recording pulse-area spectra, the gain-breakdown voltage, $V_G$, have been obtained. The voltage dependence of the Geiger-breakdown probability was determined from the fraction of zero photoelectron events with LED illumination. By comparing the results to a model calculation, the photodetection-breakdown voltage, $V_{PD}$, has been determined. Within experimental uncertainties, $V_I$ and $V_{PD}$ are equal and independent of pixel size. For $V_G$, a dependence on pixel size is observed. The difference $V_I - V_G$ is about 1 V for the SiPM with 15 $\\mu $m pixels, decreases with pixel ...

  16. Accoustic Localization of Breakdown in Radio Frequency Accelerating Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Peter Gwin [IIT, Chicago

    2016-07-01

    Current designs for muon accelerators require high-gradient radio frequency (RF) cavities to be placed in solenoidal magnetic fields. These fields help contain and efficiently reduce the phase space volume of source muons in order to create a usable muon beam for collider and neutrino experiments. In this context and in general, the use of RF cavities in strong magnetic fields has its challenges. It has been found that placing normal conducting RF cavities in strong magnetic fields reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields, it would be helpful to have a diagnostic tool which can localize the source of breakdown sparks inside the cavity. These sparks generate thermal shocks to small regions of the inner cavity wall that can be detected and localized using microphones attached to the outer cavity surface. Details on RF cavity sound sources as well as the hardware, software, and algorithms used to localize the source of sound emitted from breakdown thermal shocks are presented. In addition, results from simulations and experiments on three RF cavities, namely the Aluminum Mock Cavity, the High-Pressure Cavity, and the Modular Cavity, are also given. These results demonstrate the validity and effectiveness of the described technique for acoustic localization of breakdown.

  17. Dramatically enhanced electrical breakdown strength in cellulose nanopaper

    Directory of Open Access Journals (Sweden)

    Jianwen Huang

    2016-09-01

    Full Text Available Electrical breakdown behaviors of nanopaper prepared from nanofibrillated cellulose (NFC were investigated. Compared to conventional insulating paper made from micro softwood fibers, nanopaper has a dramatically enhanced breakdown strength. Breakdown field of nanopaper is 67.7 kV/mm, whereas that of conventional paper is only 20 kV/mm. Air voids in the surface of conventional paper are observed by scanning electron microscope (SEM. Further analyses using mercury intrusion show that pore diameter of conventional paper is around 1.7 μm, while that of nanopaper is below 3 nm. Specific pore size of nanopaper is determined to be approximately 2.8 nm by the gas adsorption technique. In addition, theoretical breakdown strengths of nanopaper and conventional paper are also calculated to evaluate the effect of pore size. It turns out that theoretical values agree well with experimental data, indicating that the improved strength in nanopaper is mainly attributed to the decreased pore size. Due to its outstanding breakdown strength, this study indicates the suitability of nanopaper for electrical insulation in ultra-high voltage convert transformers and other electrical devices.

  18. Laser-induced breakdown spectroscopy analysis of asbestos

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy was applied to test the possibility of detecting and identifying asbestos in different samples in view of the perspective at field operation without sample preparation which is peculiar to this technique. Several like-resin materials were first investigated by laser-induced breakdown spectroscopy, in order to find an asbestos container assuring safe laboratory operation during the material characterization aimed to identify indicators suitable for a quick identification on field. Successively, spectra of asbestos samples of both in serpentine and amphibole forms were measured and the variability in elemental composition was calculated from the emission spectra. Ratios of intensities of characteristic elements were tested as indicators for asbestos recognition. Laser-induced breakdown spectroscopy results were compared with those obtained by analyzing the same asbestos samples with a scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, a good correlation was found for Mg/Si and Fe/Si, thus showing the capability of laser-induced breakdown spectroscopy as a diagnostic tool for this category of materials. In particular, it was demonstrated that the method based on two indicators derived from laser-induced breakdown spectroscopy intensity ratios allows to discriminate between asbestos and cements in single shot measurements suitable to field operation

  19. Investigation of mechanism of breakdown in XLPE cables. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McKean, A.L.

    1976-07-01

    The basic hypothesis that microporosity plays a significant role in the mechanism of breakdown of XLPE cable is explored. The potential improvement achieved by impregnating the microporous regions of the cable core with a neutral liquid is evaluated, with relation to ac voltage life and impulse strength. The effect at higher frequency is also demonstrated. A similar test program is pursued on model cables, designed to explore the effects of gas pressure and gas type on breakdown and life, since it is reasonable to expect that only the microporous regions of the insulation should be sensitive to the gas-pressure environment. Comparison of gas-pressurized model breakdown stress (and related microvoid size) with basic Paschen curves demonstrates reasonably good agreement, indicating that partial discharge is the basic mechanism of fatigue and breakdown. The form of the voltage life curve above and below the discharge inception level is proposed, and evidence is presented indicating breakdown originates in the bulk insulation as well as at the shield interface. It is also shown that model cable discharge energies are below 0.1 pC, even at very high stress, and cannot be measured with modern detectors. Results with liquid or gas impregnation suggest a possible approach to dielectric improvement.

  20. Ability of sodium copper chlorophyllin complex to repair photoaged skin by stimulation of biomarkers in human extracellular matrix

    Directory of Open Access Journals (Sweden)

    McCook JP

    2016-07-01

    Full Text Available John P McCook,1 Thomas J Stephens,2 Lily I Jiang,2 Robert M Law,3 Vincent Gotz4 1Discovery Partners LLC, Frisco, 2Thomas J. Stephens & Associates, Inc., Richardson, 3ProPath, Dallas, TX, 4MDRejuvena, Inc., San Diego, CA, USA Purpose: To examine the effect of sodium copper chlorophyllin complex on the expression of biomarkers of photoaged dermal extracellular matrix indicative of skin repair.Patients and methods: Following a previously published 12-day clinical assessment model, skin biopsy samples from the forearms of four healthy females with signs of photoaged skin were obtained and samples were analyzed by immunohistochemistry for key biomarkers of aging skin after each subject was treated with a test material consisting of a gel containing a liposomal dispersion of sodium copper chlorophyllin complex 0.05%, a positive control of tretinoin cream 0.025%, and an untreated negative control.Results: There was a statistically significantly greater amount of fibrillin/amyloid P and epidermal mucins found for skin treated with the test material containing 0.05% sodium copper chlorophyllin complex and the reference control tretinoin 0.025% cream compared to the negative control (untreated site. Expression of procollagen 1 and dermal mucin also showed a greater presence in the samples treated with the test material and the reference control compared to the negative control, though the differences were not statistically significant. No adverse events were observed or reported by the subjects during the course of the study.Conclusion: The results of this human biopsy study suggest that both retinoids and sodium copper chlorophyllin complex have beneficial effects on biomarkers of photoaged skin. Products containing both sodium copper chlorophyllin complex and retinols may provide a dual approach to reversing age-related decreases in hyaluronic acid (HA in the skin: inhibition of the breakdown of HA via sodium copper chlorophyllin complex by inhibition

  1. Surface Breakdown Characteristics of Silicone Oil for Electric Power Apparatus

    Science.gov (United States)

    Wada, Junichi; Nakajima, Akitoshi; Miyahara, Hideyuki; Takuma, Tadasu; Okabe, Shigemitu; Kohtoh, Masanori; Yanabu, Satoru

    This paper describes the surface breakdown characteristics of the silicone oil which has the possibility of the application to innovative switchgear as an insulating medium. At the first step, we have experimentally studied on the impulse breakdown characteristics of the configuration with a triple-junction where a solid insulator is in contact with the electrode. The test configurations consist of solid material (Nomex and pressboard) and liquid insulation oil (silicone and mineral oil). We have discussed the experimental results based on the maximal electric field at a triple-junction. As the second step, we have studied the configuration which may improve the surface breakdown characteristics by lowering the electric field near the triple-junction.

  2. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  3. Electrical breakdown gas detector featuring carbon nanotube array electrodes.

    Science.gov (United States)

    Kim, Seongyul; Pal, Sunil; Ajayan, Pulickel M; Borca-Tasciuc, Theodorian; Koratkar, Nikhil

    2008-01-01

    We demonstrate here detection of dichloro-difluoro-methane and oxygen in mixtures with helium using a carbon nanotube electrical breakdown sensor device. The sensor is comprised of an aligned array of multiwalled carbon nanotubes deposited on a nickel based super-alloy (Inconel 600) as the anode; the counter electrode is a planar nickel sheet. By monitoring the electrical breakdown characteristics of oxygen and dichloro-difluoro-methane in a background of helium, we find that the detection limit for dichloro-difluoro-methane is approximately 0.1% and the corresponding limit for oxygen is approximately 1%. A phenomenologigal model is proposed to describe the trends observed in detection of the two mixtures. These results indicate that carbon nanotube based electrical breakdown sensors show potential as end detectors in gas-chromatography devices. PMID:18468093

  4. Fundamentals of undervoltage breakdown through the Townsend mechanism

    Science.gov (United States)

    Cooley, James E.

    The conditions under which an externally supplied pulse of electrons will induce breakdown in an undervoltaged, low-gain, DC discharge gap are experimentally and theoretically explored. The phenomenon is relevant to fundamental understanding of breakdown physics, to switching applications such as triggered spark gaps and discharge initiation in pulsed-plasma thrusters, and to gas-avalanche particle counters. A dimensionless theoretical description of the phenomenon is formulated and solved numerically. It is found that a significant fraction of the charge on the plates must be injected for breakdown to be achieved at low avalanche-ionization gain, when an electron undergoes fewer than approximately 10 ionizing collisions during one gap transit. It is also found that fewer injected electrons are required as the gain due to electron-impact ionization (alpha process) is increased, or as the sensitivity of the alpha process to electric field is enhanced by decreasing the reduced electric field (electric field divided by pressure, E/p). A predicted insensitivity to ion mobility implies that breakdown is determined during the first electron avalanche when space charge distortion is greatest. A dimensionless, theoretical study of the development of this avalanche reveals a critical value of the reduced electric field to be the value at the Paschen curve minimum divided by 1.6. Below this value, the net result of the electric field distortion is to increase ionization for subsequent avalanches, making undervoltage breakdown possible. Above this value, ionization for subsequent avalanches will be suppressed and undervoltage breakdown is not possible. Using an experimental apparatus in which ultraviolet laser pulses are directed onto a photo-emissive cathode of a parallel-plate discharge gap, it is found that undervoltage breakdown can occur through a Townsend-like mechanism through the buildup of successively larger avalanche generations. The minimum number of injected

  5. Establishing Causality in Complex Human Interactions: Identifying Breakdowns of Intentionality

    Science.gov (United States)

    Goodison, Peter; Johnson, Peter; Thoms, Joanne

    People in complex scenarios face the challenge of understanding the purpose and effect of other human and computational behaviour on their own goals through intent recognition. They are left asking what caused person or system ‘x’ to do that? The necessity to provide this support human-computer interaction has increased alongside the deployment of autonomous systems that are to some degree unsupervised. This paper aims to examine intent recognition as a form of decision making about causality in complex systems. By finding the needs and limitations of this decision mechanism it is hoped this can be applied to the design of systems to support the awareness of information cues and reduce the number of intent recognition breakdowns between people and autonomous systems. The paper outlines theoretical foundations for this approach using simulation theory and process models of intention. The notion of breakdowns is then applied to intent recognition breakdowns in a diary study to gain insight into the phenomena.

  6. A Model of Protocoalition Bargaining with Breakdown Probability

    Directory of Open Access Journals (Sweden)

    Maria Montero

    2015-04-01

    Full Text Available This paper analyses a model of legislative bargaining in which parties form tentative coalitions (protocoalitions before deciding on the allocation of a resource. Protocoalitions may fail to reach an agreement, in which case they may be dissolved (breakdown and a new protocoalition may form. We show that agreement is immediate in equilibrium, and the proposer advantage disappears as the breakdown probability goes to zero. We then turn to the special case of apex games and explore the consequences of varying the probabilities that govern the selection of formateurs and proposers. Letting the breakdown probability go to zero, most of the probabilities considered lead to the same ex post pay-off division. Ex ante expected pay-offs may follow a counterintuitive pattern: as the bargaining power of weak players within a protocoalition increases, the weak players may expect a lower pay-off ex ante.

  7. Electron cyclotron resonance breakdown studies in a linear plasma system

    Indian Academy of Sciences (India)

    Vipin K Yadav; K Sathyanarayana; D Bora

    2008-03-01

    Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases - hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02 GHz in TE10 mode and launched radially to have extra-ordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the fundamental ECR surface ( = 875.0 G) resides at the geometrical centre of the plasma system. ECR breakdown parameters such as plasma delay time and plasma decay time from plasma density measurements are carried out at the centre using a Langmuir probe. The operating parameters such as working gas pressure (1 × 10-5 -1 × 10-2 mbar) and input microwave power (160{800 W) are varied and the corresponding effect on the breakdown parameters is studied. The experimental results obtained are presented in this paper.

  8. Exploring Biomarkers for Alzheimer's Disease.

    Science.gov (United States)

    Sharma, Neeti; Singh, Anshika Nikita

    2016-07-01

    Alzheimer's Disease (AD) is one of the most common form of dementia occurring in elderly population worldwide. Currently Aβ42, tau and p-tau in the cerebrospinal fluid is estimated for confirmation of AD. CSF which is being used as the potent source for biomarker screening is obtained by invasive lumbar punctures. Thus, there is an urgent need of minimal invasive methods for identification of diagnostic markers for early detection of AD. Blood serum and plasma serves as an appropriate source, due to minimal discomfort to the patients, promoting frequent testing, better follow-up and better consent to clinical trials. Hence, the need of the hour demands discovery of diagnostic and prognostic patient specific signature biomarkers by using emerging technologies of mass spectrometry, microarrays and peptidomics. In this review we summarize the present scenario of AD biomarkers such as circulatory biomarkers, blood based amyloid markers, inflammatory markers and oxidative stress markers being investigated and also some of the potent biomarkers which might be able to predict early onset of Alzheimer's and delay cognitive impairment. PMID:27630867

  9. New phenomenology of gas breakdown in DC and RF fields

    Science.gov (United States)

    Petrović, Zoran Lj; Sivoš, Jelena; Savić, Marija; Škoro, Nikola; Radmilović Radenović, Marija; Malović, Gordana; Gocić, Saša; Marić, Dragana

    2014-05-01

    This paper follows a review lecture on the new developments in the field of gas breakdown and low current discharges, usually covered by a form of Townsend's theory and phenomenology. It gives an overview of a new approach to identifying which feedback agents provide breakdown, how to model gas discharge conditions and reconcile the results with binary experiments and how to employ that knowledge in modelling gas discharges. The next step is an illustration on how to record volt-ampere characteristics and use them on one hand to obtain the breakdown voltage and, on the other, to identify the regime of operation and model the secondary electron yields. The second aspect of this section concerns understanding the different regimes, their anatomy, how those are generated and how free running oscillations occur. While temporal development is the most useful and interesting part of the new developments, the difficulty of presenting the data in a written form precludes an easy publication and discussion. Thus, we shall only mention some of the results that stem from these measurements. Most micro discharges operate in DC albeit with complex geometries. Thus, parallel plate micro discharge measurements were needed to establish that Townsend's theory, with all its recent extensions, is still valid until some very small gaps. We have shown, for example, how a long-path breakdown puts in jeopardy many experimental observations and why a flat left-hand side of the Paschen curve often does not represent good physics. We will also summarize a kinetic representation of the RF breakdown revealing a somewhat more complex picture than the standard model. Finally, we will address briefly the breakdown in radially inhomogeneous conditions and how that affects the measured properties of the discharge. This review has the goal of summarizing (rather than developing details of) the current status of the low-current DC discharges formation and operation as a discipline which, in spite of

  10. Breakdown voltage in thin III-V avalanche photodiodes

    Science.gov (United States)

    Saleh, Mohammad A.; Hayat, Majeed M.; Kwon, Oh-Hyun; Holmes, Archie L.; Campbell, Joe C.; Saleh, Bahaa E. A.; Teich, Malvin C.

    2001-12-01

    The dead-space multiplication theory of Hayat and Saleh [J. Lightwave Technol. 10, 1415 (1992)], in conjunction with the multiplication-width-independent ionization-coefficient model developed by Saleh et al. [IEEE Trans. Electron Devices 47, 625 (2000)], are shown to accurately predict breakdown voltages for thin avalanche photodiodes of GaAs, InP, In0.52Al0.48As, and Al0.2Ga0.8As, over a broad range of device widths. The breakdown voltage is determined from the analytical expression for the impulse-response-function decay rate.

  11. Direct relationship between breakdown strength and tracking index of composites

    DEFF Research Database (Denmark)

    Madsen, Søren Find; Henriksen, Mogens; Holbøll, Joachim

    2006-01-01

    The following paper shows a clear correlation between the measured tracking index and the breakdown field strength for noncoated glass fibre reinforced polymers (GFRP) with either a polyester or an epoxy based resin. 17 types of specimens have been tested according to IEC Publication 60587....... The breakdown field strength of specimens cut from similar samples is determined by a new method capable of estimating the stressed volume. The results from the two tests are finally compared and incorporated in a single analytical formula. All test specimens are supplied by Danish manufacturers of wind turbine...

  12. Biomarkers of silicosis: Potential candidates

    Directory of Open Access Journals (Sweden)

    Tiwari R

    2005-01-01

    Full Text Available Silica dust is widely prevalent in the atmosphere and more common than the other types of dust, thus making silicosis the most frequently occurring pneumoconiosis. In India also, studies carried out by National Institute of Occupational Health have shown high prevalence of silicosis in small factories and even in nonoccupational exposed subjects. The postero-anterior chest radiographs remain the key tool in diagnosing and assessing the extent and severity of interstitial lung disease. Although Computed Tomography detects finer anatomical structure than radiography it could not get popularity because of its cost. On the basis of histological features of silicosis many potential biomarkers such as Cytokines, Tumor Necrosis Factor, Interleukin 1, Angiotensin Converting Enzyme, Serum Copper, Fas ligand (FasL, etc. have been tried. However, further studies are needed to establish these potential biomarkers as true biomarker of silicosis.

  13. Biomarkers in fibromyalgia: a review

    Directory of Open Access Journals (Sweden)

    Giacomelli C

    2014-02-01

    Full Text Available Camillo Giacomelli,* Francesca Sernissi,* Alessandra Rossi, Stefano Bombardieri, Laura BazzichiRheumatology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy *These authors contributed equally to the manuscript Abstract: Fibromyalgia is a common syndrome diagnosed by clinical criteria. The main symptom of fibromyalgia is pain, but patients frequently also complain about other nonspecific symptoms, such as headache, sleep disturbance, mood disorder, and cognitive impairment. In the light of the multifactorial origin of the disease and of the lack of objective diagnostic findings, several attempts have been made to find a reliable biomarker. For this reason, over the years, a number of patients and various biological samples have been studied, using many different approaches and techniques. Despite this, none of these studies has been able to find the proper biomarker. The aim of this review is to provide a critical overview of the current environment characterizing the search for fibromyalgia biomarkers. Keywords: genetics, proteomics, oxidative stress, fibromyalgia

  14. Bias in Peripheral Depression Biomarkers

    DEFF Research Database (Denmark)

    Carvalho, André F; Köhler, Cristiano A; Brunoni, André R;

    2016-01-01

    BACKGROUND: To aid in the differentiation of individuals with major depressive disorder (MDD) from healthy controls, numerous peripheral biomarkers have been proposed. To date, no comprehensive evaluation of the existence of bias favoring the publication of significant results or inflating effect...... sizes has been conducted. METHODS: Here, we performed a comprehensive review of meta-analyses of peripheral nongenetic biomarkers that could discriminate individuals with MDD from nondepressed controls. PubMed/MEDLINE, EMBASE, and PsycINFO databases were searched through April 10, 2015. RESULTS: From 15......-analyses, while 11 meta-analyses had evidence of small-study effects. CONCLUSIONS: Our findings suggest that there is an excess of studies with statistically significant results in the literature of peripheral biomarkers for MDD. The selective publication of 'positive studies' and the selective reporting...

  15. Biomarkers in inflammatory bowel diseases

    DEFF Research Database (Denmark)

    Bennike, Tue; Birkelund, Svend; Stensballe, Allan;

    2014-01-01

    Unambiguous diagnosis of the two main forms of inflammatory bowel diseases (IBD): Ulcerative colitis (UC) and Crohn's disease (CD), represents a challenge in the early stages of the diseases. The diagnosis may be established several years after the debut of symptoms. Hence, protein biomarkers...... for early and accurate diagnostic could help clinicians improve treatment of the individual patients. Moreover, the biomarkers could aid physicians to predict disease courses and in this way, identify patients in need of intensive treatment. Patients with low risk of disease flares may avoid treatment...... with medications with the concomitant risk of adverse events. In addition, identification of disease and course specific biomarker profiles can be used to identify biological pathways involved in the disease development and treatment. Knowledge of disease mechanisms in general can lead to improved future...

  16. A relationship between statistical time to breakdown distributions and pre-breakdown negative differential resistance at nanometric scale

    Energy Technology Data Exchange (ETDEWEB)

    Foissac, R. [STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Univ. Grenoble Alpes, LTM, F-38000 Grenoble, France and CNRS, LTM, F-38000 Grenoble (France); Blonkowski, S.; Delcroix, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Kogelschatz, M. [Univ. Grenoble Alpes, LTM, F-38000 Grenoble, France and CNRS, LTM, F-38000 Grenoble (France)

    2014-07-14

    Using an ultra-high vacuum Conductive atomic force microscopy (C-AFM) current voltage, pre-breakdown negative differential resistance (NDR) characteristics are measured together with the time dependent dielectric breakdown (TDDB) distributions of Si/SiON (1.4 and 2.6 nm thick). Those experimental characteristics are systematically compared. The NDR effect is modelled by a conductive filament growth. It is showed that the Weibull TDDB statistic distribution scale factor is proportional to the growth rate of an individual filament and then has the same dependence on the electric field. The proportionality factor is a power law of the ratio between the surfaces of the CAFM tip and the filament's top. Moreover, it was found that, for the high fields used in those experiments, the TDDB acceleration factor as the growth rate characteristic is proportional to the Zener tunnelling probability. Those observations are discussed in the framework of possible breakdown or forming mechanism.

  17. Potential blood biomarkers for stroke.

    Science.gov (United States)

    Laborde, Carlos M; Mourino-Alvarez, Laura; Akerstrom, Finn; Padial, Luis R; Vivanco, Fernando; Gil-Dones, Felix; Barderas, Maria G

    2012-08-01

    Stroke is one of the most common causes of death worldwide and a major cause of acquired disability in adults. Despite advances in research during the last decade, prevention and treatment strategies still suffer from significant limitations, and therefore new theoretical and technical approaches are required. Technological advances in the proteomic and metabolomic areas, during recent years, have permitted a more effective search for novel biomarkers and therapeutic targets that may allow for effective risk stratification and early diagnosis with subsequent rapid treatment. This review provides a comprehensive overview of the latest candidate proteins and metabolites proposed as new potential biomarkers in stroke. PMID:22967080

  18. Quantitative analysis of metformin in antidiabetic tablets by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Contreras, U.; Ornelas-Soto, N.; Meneses-Nava, M. A.; Barbosa-García, O.; López-de-Alba, P. L.; López-Martínez, L.

    2011-09-01

    Nowadays the production of counterfeit and low quality drugs affects human health and generates losses to pharmaceutical industries and tax revenue losses to government. Currently there are several methods for pharmaceutical product analysis; nevertheless, most of them depend on complex and time consuming steps such as sample preparation. In contrast to conventional methods, Laser-induced breakdown spectroscopy (LIBS) is evaluated as a potential analytical technique for the rapid screening and quality control of anti-diabetic solid formulations. In this paper authors propose a simple method to analyze qualitatively and quantitatively Active Pharmaceutical Ingredients (APIs) such as Metformin hydrochloride. The authors used ten nanosecond duration pulses (FWHM) from a Nd:YAG laser produces the induced breakdown for the analysis. Light is collected and focused into a Cerny-Turner spectrograph and dispersed into an ICCD camera for its detection. We used atomic emissions from Chlorine atoms present only in APIs as analyte signal. The analysis was improved using Bromine as internal standard. Linear calibration curves from synthetic samples were prepared achieving linearity higher than 99%. Our results were compared with HPLC results and validation was performed by statistical methods. The validation analysis suggests that both methods have no significant differences i.e., the proposed method can be implemented for monitoring the pharmaceutical production process in-situ in real time or for inspection and recognition of authenticity.

  19. Biomarker Detection using PS2-Thioaptamers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AM Biotechnologies (AM) will develop a system to detect and quantify bone demineralization biomarkers as outlined in SBIR Topic "Technologies to Detect Biomarkers"....

  20. Proteomics in Discovery of Hepatocellular Carcinoma Biomarkers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To discover new proteomic biomarkers of hepatocellular carcinoma. Methods: Surface enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry was used to discover biomarkers for differentiating hepatocellular carcinoma and chronic liver disease. A population of 50 patients with hepatocellular carcinoma and 33 patients with chronic liver disease was studied. Results: Twelve proteomic biomarkers of hepatocellular carcinoma were detected in this study. Three proteomic biomarkers were highly expressed in hepatocellular carcinoma and nine proteomic biomarkers were highly expressed in chronic liver disease. The most valuable proteomic biomarker with m/z=11498 had no similar diagnostic value as α-fetoprotein. Conclusion:Some of the twelve proteomic biomarkers may become new biomarkers of hepatocellular carcinoma.

  1. Personalized medicine using DNA biomarkers: a review

    OpenAIRE

    Ziegler, Andreas; Koch, Armin; Krockenberger, Katja; Großhennig, Anika

    2012-01-01

    Biomarkers are of increasing importance for personalized medicine, with applications including diagnosis, prognosis, and selection of targeted therapies. Their use is extremely diverse, ranging from pharmacodynamics to treatment monitoring. Following a concise review of terminology, we provide examples and current applications of three broad categories of biomarkers—DNA biomarkers, DNA tumor biomarkers, and other general biomarkers. We outline clinical trial phases for identifying and validat...

  2. Local late Amazonian boulder breakdown and denudation rate on Mars

    NARCIS (Netherlands)

    de Haas, T.; Hauber, E.; Kleinhans, M.G.

    2013-01-01

    Inactive fan surfaces become smoother and develop desert pavement over time by weathering and erosion. We use this mechanism to estimate late Amazonian boulder breakdown and surface denudation rates on a young (∼1.25 Ma) (Schon et al., 2009) fan on Mars. This is done by comparing boulder size and su

  3. The breakdown phase in a coaxial plasma gun

    International Nuclear Information System (INIS)

    The electrical breakdown in a coaxial plasma gun was investigated by means of optical and electrical measurements. The optimum start and operation conditions of the gun turned out to be strongly dependent on material and length of the cylindrical insulator. (orig.)

  4. Determining the mode of high voltage breakdowns in vacuum devices

    Science.gov (United States)

    Miller, H. C.; Furno, E. J.; Sturtz, J. P.

    1980-07-01

    Techniques for examining high voltage breakdowns (HVBs) in vacuum devices are discussed. Photography in conjunction with other diagnostic techniques is used to establish the validity of these techniques. The techniques examined are to measure the voltage applied to the device (or the current through the device) and also to look for X-rays generated by the device during an HVB.

  5. Effects of streamwise vortex breakdown on supersonic combustion.

    Science.gov (United States)

    Hiejima, Toshihiko

    2016-04-01

    This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1. PMID:27176398

  6. Recovering from trust breakdowns in large system Implementations

    DEFF Research Database (Denmark)

    Schlichter, Bjarne Rerup; Andersen, Povl Erik Rostgård

    On the basis of experiences from the Faroese large-scale implementation of integrated healthcare information systems and insights into dynamic aspects of trust, we offer the following lessons learned for the successful management and recovery of trust (breakdowns) in large system implementations...

  7. Recovering from trust breakdowns in large system implementations

    DEFF Research Database (Denmark)

    Rerup Schlichter, Bjarne Rerup; Andersen, Povl Erik Rostgård

    2011-01-01

    On the basis of experiences from the Faroese large-scale implementation of integrated healthcare information systems and insights into dynamic aspects of trust, we offer the following lessons learned for the successful management and recovery of trust (breakdowns) in large system implementations...

  8. Breakdown of large-scale circulation in turbulent rotating convection

    NARCIS (Netherlands)

    Kunnen, R.P.J.; Clercx, H.J.H.; Geurts, B.J.

    2008-01-01

    Turbulent rotating convection in a cylinder is investigated both numerically and experimentally at Rayleigh number Ra=109 and Prandtl number σ=6.4. In this letter we discuss two topics: the breakdown under rotation of the domain-filling large-scale circulation (LSC) typical for confined convection,

  9. Using Work Breakdown Structure Models to Develop Unit Treatment Costs

    Science.gov (United States)

    This article presents a new cost modeling approach called work breakdown structure (WBS), designed to develop unit costs for drinking water technologies. WBS involves breaking the technology into its discrete components for the purposes of estimating unit costs. The article dem...

  10. Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs

  11. Marital Breakdown, Shame, and Suicidality in Men: A Direct Link?

    Science.gov (United States)

    Kolves, Kairi; Ide, Naoko; De Leo, Diego

    2011-01-01

    The influence of feelings of shame originating from marital breakdown on suicidality is examined. The role of mental health problems as probable mediating factors is also considered. Internalized shame, state (related to separation) shame, and mental health problems were significantly correlated with the score for suicidality during separation in…

  12. Pattern Analysis on DC Breakdown Phenomenon of Polyethylene Films

    Institute of Scientific and Technical Information of China (English)

    DU Boxue; LIU Yong; LIU Hongjing

    2006-01-01

    Pattern analysis method was used to study DC breakdown characteristics of low-density polyethylene(LDPE)film and high-density polyethylene(HDPE)film, with particular attention paid to the breakdown phenomenon identification. The breakdown pattern(BP)was recorded by a monocular-video-zoom microscope. The records showed that the effective area of BP was almost identical to the types of electrodes. The effective area was calculated by a mathematical integral method. The diameter was obtained by a mathematical statistic method. The study revealed that the DC breakdown voltage of LDPE was lower than that of HDPE. The diameter and effective area of LDPE were smaller than those of HDPE, but it is opposite for the condition of the needle-plane electrode with plane electrode grounded. As for the needle-plane electrode, the diameter and effective area with the films near the needle electrode were smaller than those near the plane electrode, and those in the middle of air gap were between them. As for the sphere-plane electrode, the diameter and effective area with the films near the plane electrode were smaller than those near the sphere electrode, and those in the middle of air gap were between them.

  13. RF breakdown of 805 MHz cavities in strong magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Bowring, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Stratakis, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kochemirovskiy, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Leonova, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Moretti, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Palmer, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Peterson, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yonehara, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Freemire, B. [Illinois Inst. of Technology, Chicago, IL (United States); Lane, P. [Illinois Inst. of Technology, Chicago, IL (United States); Torun, Y. [Illinois Inst. of Technology, Chicago, IL (United States); Haase, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-05-03

    Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.

  14. A numerical study of three-dimensional vortex breakdown

    Science.gov (United States)

    Spall, Robert E.; Ash, Robert L.

    1987-01-01

    A numerical simulation of bubble-type vortex breakdown using a unique discrete form of the full 3-D, unsteady incompressible Navier-Stokes equations was performed. The Navier-Stokes equations were written in a vorticity-velocity form and the physical problem was not restricted to axisymmetric flow. The problem was parametized on a Rossby- Reynolds-number basis. Utilization of this parameter duo was shown to dictate the form of the free-field boundary condition specification and allowed control of axial breakdown location within the computational domain. The structure of the breakdown bubble was studied through time evolution plots of planar projected velocity vectors as well as through plots of particle traces and vortex lines. These results compared favorably with previous experimental studies. In addition, profiles of all three velocity components are presented at various axial stations and a Fourier analysis was performed to identify the dominant circumferential modes. The dynamics of the breakdown process were studied through plots of axial variation of rate of change of integrated total energy and rate of change of integrated enstrophy, as well as through contour plots of velocity, vorticity and pressure.

  15. Laser-Induced Breakdown Spectroscopy and Chlorophyll a Flourescence Transients

    DEFF Research Database (Denmark)

    Frydenvang, Jens

    of a sufficient quality; something that remains a problem for many in-situ methods. In my PhD, I present my work with two such in-situ methods, Laser-Induced Breakdown Spectroscopy (LIBS) and OJIP transients, the rising part of chlorophyll a fluorescence transients from dark-adapted leaves....

  16. Time-to-breakdown characteristics of magnetic tunnel junctions

    International Nuclear Information System (INIS)

    To investigate the reliability of the MTJs on the roughness of insulating tunnel barrier, we prepared two MTJs with the different uniformity of barrier thickness. Namely, the one has uniform insulating barrier thickness; the other has non-uniform insulating barrier thickness as compared to different thing. As to depositing amorphous layer CoZrNb under the pinning layer IrMn, we achieved MTJ with uniform barrier thickness. First of all, we performed the breakdown-voltage measurement of two junctions and obtained the result having a similar breakdown-voltage about 1.4 V at two all junctions. And then, the time dependence dielectric breakdown (TDDB) measurements of two junctions are carried out under constant voltage stresses. The Weibull fit of our data shows clearly that time to breakdown (tBD) scales with the thickness uniformity of tunnel barrier. And also, Assuming a linear dependence of log(tBD) on stress voltages, we meet with result about the different lifetime of the two MTJs with uniform barrier thickness or non-uniform barrier thickness. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Time-to-breakdown characteristics of magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae Youn; Rhee, Jang Roh [Department of Physics, Sookmyung Women' s University, Seoul 140-742 (Korea); Kim, Taewan; Park, Wanjun [Materials and Devices Laboratory, Samsung Advanced Institute of Technology, Gyeonggi-Do 449-711 (Korea); Jang, YoungMan; Cho, B.K. [Superconducting and Magnetic Materials Laboratory, GwangJu Institute of Science and Technology, Gwangju 500-712 (Korea)

    2004-12-01

    To investigate the reliability of the MTJs on the roughness of insulating tunnel barrier, we prepared two MTJs with the different uniformity of barrier thickness. Namely, the one has uniform insulating barrier thickness; the other has non-uniform insulating barrier thickness as compared to different thing. As to depositing amorphous layer CoZrNb under the pinning layer IrMn, we achieved MTJ with uniform barrier thickness. First of all, we performed the breakdown-voltage measurement of two junctions and obtained the result having a similar breakdown-voltage about 1.4 V at two all junctions. And then, the time dependence dielectric breakdown (TDDB) measurements of two junctions are carried out under constant voltage stresses. The Weibull fit of our data shows clearly that time to breakdown (t{sub BD}) scales with the thickness uniformity of tunnel barrier. And also, Assuming a linear dependence of log(t{sub BD}) on stress voltages, we meet with result about the different lifetime of the two MTJs with uniform barrier thickness or non-uniform barrier thickness. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Pulsed and streamer discharges in air above breakdown electric field

    NARCIS (Netherlands)

    Sun, A.B.; Teunissen, H.J.; Ebert, U.

    2013-01-01

    A 3D particle model is developed to investigate the streamer formation in electric fields above the breakdown threshold, in atmospheric air (1bar, 300 Kelvin). Adaptive particle management, adaptive mesh refinement and parallel computing techniques are used in the code. Photoionization and electron

  19. Controlled electron emission and vacuum breakdown with nanosecond pulses

    Science.gov (United States)

    Seznec, B.; Dessante, Ph; Caillault, L.; Babigeon, J.-L.; Teste, Ph; Minea, T.

    2016-06-01

    Vacuum electron sources exploiting field emission are generally operated in direct current (DC) mode. The development of nanosecond and sub-nanosecond pulsed power supplies facilitates the emission of compact bunches of electrons of high density. The breakdown level is taken as the highest value of the voltage avoiding the thermo-emission instability. The effect of such ultra-fast pulses on the breakdown voltage and the emitted electron current is discussed as a result of the thermo-emission modelling applied to a significant protrusion. It is found that pulsing very rapidly the vacuum breakdown occurs at higher voltage values than for the DC case, because it rises faster than the heat diffusion. In addition, the electron emission current increases significantly regardless of the theoretical approach is used. A comparative study of this theoretical work is discussed for several different forms of the protrusion (elliptic and hyperbolic) and different metals (hence varying the melting point), particularly refractory (tungsten) versus conductor (titanium). Pulsed mode operation can provide an increase on breakdown voltage (up to 18%) and a significant increase (up to 330%) of the electron extracted current due to its high non-linear dependency with the voltage, for the case for the case with a hyperbolic protrusion.

  20. The electrical breakdown of thin dielectric elastomers: thermal effects

    Science.gov (United States)

    Zakaria, Shamsul; Morshuis, Peter H. F.; Benslimane, Mohamed Y.; Gernaey, Krist V.; Skov, Anne L.

    2014-03-01

    Dielectric elastomers are being developed for use in actuators, sensors and generators to be used in various applications, such as artificial eye lids, pressure sensors and human motion energy generators. In order to obtain maximum efficiency, the devices are operated at high electrical fields. This increases the likelihood for electrical breakdown significantly. Hence, for many applications the performance of the dielectric elastomers is limited by this risk of failure, which is triggered by several factors. Amongst others thermal effects may strongly influence the electrical breakdown strength. In this study, we model the electrothermal breakdown in thin PDMS based dielectric elastomers in order to evaluate the thermal mechanisms behind the electrical failures. The objective is to predict the operation range of PDMS based dielectric elastomers with respect to the temperature at given electric field. We performed numerical analysis with a quasi-steady state approximation to predict thermal runaway of dielectric elastomer films. We also studied experimentally the effect of temperature on dielectric properties of different PDMS dielectric elastomers. Different films with different percentages of silica and permittivity enhancing filler were selected for the measurements. From the modeling based on the fitting of experimental data, it is found that the electrothermal breakdown of the materials is strongly influenced by the increase in both dielectric permittivity and conductivity.

  1. Breakdown phenomenon in insulators of submarine power cables

    OpenAIRE

    Malec, D.; Essolbi, R.

    1993-01-01

    Dielectric characteristics of polyethylenes used for the cable insulation under submarine working conditions (temperature and pressure) have been investigated by the authors. From experimental results, a modelling of the short time breakdown was proposed by numerically solving the fundamental heat balance equation. Electromechanical effect has been also taken into account in this model. Theoretical results are in good agreement with observed data.

  2. A study of vortex breakdown in supercritical fluids

    Science.gov (United States)

    Crook, Loren C.

    The objective of this thesis is to evaluate the hydrodynamic stability theory of vortex breakdown by examining its presence in a swirling supercritical fluid jet. Supercritical fluids were chosen because they are technologically important, and because their strong density gradients near the critical point provide a self-excitable flow regime where hydrodynamic instabilities should be more easily identified. Computations were developed to provide flow conditions for experimental observation of vortex breakdown and to estimate hydrodynamic flow instabilities prior to testing. The RANS computations of an axial-plus-tangential air swirler were developed and verified as grid-independent and in agreement with experimental results reported in the literature. The computations also produced a correlation of momentum swirl number as a function of mass ratio (tangential/total) for estimating swirl number during experiments. Finally, the computations were extended to simulate supercritical CO2 in an axial-plus-tangential swirler that was compatible with the supercritical injection facility. Three mass flow ratio cases were investigated extensively: no-swirl (0%), low-swirl prior to breakdown (25%), and moderate swirl with breakdown (45%). (The three corresponding momentum swirl numbers for these mass flow ratios were 0.0, 0.30 and 0.80.) These three cases also served as the basis for the experimental portion of the work. Swirling supercritical fluid jets were observed in the injection facility using schlieren imaging for three separate swirl numbers. The Sobel method was used to locate the jet edges. The jets were characterized by their radii, including mean and standard deviation, and spreading angles as functions of swirl number and density ratio (2.3, 2.6, and 5.0). The swirl number was identified as the dominant parameter in determining the spreading angle and jet radius. Vortex breakdown was identified as the jet structure changed from straight edges to curved, signifying

  3. Biomarkers in sarcoidosis: a review

    Directory of Open Access Journals (Sweden)

    Ahmadzai H

    2014-08-01

    Full Text Available Hasib Ahmadzai,1,2 Wei Sheng Joshua Loke,1 Shuying Huang,1 Cristan Herbert,1 Denis Wakefield,3 Paul S Thomas2 1Inflammation and Infection Research Centre (IIRC, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia; 2Department of Respiratory Medicine, Prince of Wales Hospital, Randwick, Sydney, NSW, Australia; 3Immunology of the Eye Clinic, St Vincent's Clinic, Darlinghurst, Sydney, NSW, Australia Abstract: Sarcoidosis is a systemic granulomatous disease of undetermined etiology invariably affecting the lungs and thoracic lymph nodes. It has been termed an “immune paradox”, as there is peripheral anergy despite exaggerated inflammation at disease sites. The disease is usually self-limiting, although some individuals experience unremitting inflammation that may progress into pulmonary fibrosis and death. The inflammatory process is largely a T helper-1-driven immune response. Given its heterogeneous clinical manifestations, diagnosis is usually a clinical conundrum. Clinical and radiological findings alone are often inadequate to confirm the diagnosis. At present, sarcoidosis is usually a diagnosis of exclusion, confirmed by histological evidence of noncaseating granulomas in the absence of known granulomagenic agents. This has compelled researchers to look for disease-specific biomarkers that can help diagnose sarcoidosis and delineate its disease course, severity, and prognosis. In this review we highlight various investigations used to diagnose sarcoidosis, outline proposed biomarkers, and discuss novel methods of sampling biomarkers. Keywords: sarcoidosis, biomarkers, inflammatory markers, exhaled breath condensate, proteomics, granuloma

  4. Biomarkers of satiation and satiety

    NARCIS (Netherlands)

    Graaf, C. de; Blom, W.A.M.; Smeets, P.A.M.; Stafleu, A.; Hendriks, H.F.J.

    2004-01-01

    This review's objective is to give a critical summary of studies that focused on physiologic measures relating to subjectively rated appetite, actual food intake, or both. Biomarkers of satiation and satiety may be used as a tool for assessing the satiating efficiency of foods and for understanding

  5. Biomarkers of replicative senescence revisited

    DEFF Research Database (Denmark)

    Nehlin, Jan

    2016-01-01

    of telomere length and associated damage, and the accompanying changes that take place elicit signals that have an impact on a number of molecules and downstream events. Precise measurements of replicative senescence biomarkers in biological samples from individuals could be clinically associated...

  6. Statistical time lags in low-pressure SF6 breakdown

    Science.gov (United States)

    Woolsey, G. A.; Ogle, D. B.

    1989-10-01

    Statistical time lags have been measured in a discharge tube containing SF6 at a pressure of 1 Torr, with the aim of determining the source of the electrons which initiate breakdownY`Te,hf cx pressure SF6. Measurements with and without careful shielding of the discharge tube give similar values of mean statistical time lag showing that the initiating electrons are not produced by external radiation. Measurements, in which the time between the 500 successive breakdowns used for a single measurement of mean statistical time lag is increased over the range 1-103 s, provide values of mean statistical time lag which increase over the range 10-5-10-2s: This reveals that the breakdown process is controlled by the time since the discharge produced by a previous breakdown. Data from further such measurements, made for different applied tube voltages, are shown to fit well with the Fowler-Nordheim theory of field emission. The conclusion drawn is that the initiating electrons are produced at the cathode surface by field emission, and that the state of the surface at any time depends primarily on the intensity of the previous discharge and the length of time since it took place. During the time between successive breakdowns, a surface layer on the cathode surface is continually developing and reducing the rate of field emission from the cathode. Although the applied electric fields are well below that required for field emission, microscopic fields exist at protrusions and craters on the cathode surface which are high enough to provide field emission: This is supported by experiments on electron emission made with the discharge tube evacuated below 10-6 Torr.

  7. The Functional Breakdown Structure (FBS) and Its Relationship to Life Cycle Cost

    Science.gov (United States)

    DeHoff, Bryan; Levack, Danie J. H.; Rhodes, Russell E.

    2009-01-01

    The Functional Breakdown Structure (FBS) is a structured, modular breakdown of every function that must be addressed to perform a generic mission. It is also usable for any subset of the mission. Unlike a Work Breakdown Structure (WBS), the FBS is a function-oriented tree, not a product-oriented tree. The FBS details not products, but operations or activities that should be performed. The FBS is not tied to any particular architectural implementation because it is a listing of the needed functions, not the elements, of the architecture. The FBS for Space Transportation Systems provides a universal hierarchy of required functions, which include ground and space operations as well as infrastructure - it provides total visibility of the entire mission. By approaching the systems engineering problem from the functional view, instead of the element or hardware view, the SPST has created an exhaustive list of potential requirements which the architecture designers can use to evaluate the completeness of their designs. This is a new approach that will provide full accountability of all functions required to perform the planned mission. It serves as a giant check list to be sure that no functions are omitted, especially in the early architectural design phase. A significant characteristic of a FBS is that if architecture options are compared using this approach, then any missing or redundant elements of each option will be ' identified. Consequently, valid Life Cycle Costs (LCC) comparisons can be made. For example, one architecture option might not need a particular function while another option does. One option may have individual elements to perform each of three functions while another option needs only one element to perform the three functions. Once an architecture has been selected, the FBS will serve as a guide in development of the work breakdown structure, provide visibility of those technologies that need to be further developed to perform required functions

  8. Comprehensive Definitions of Breakdown-Points for Independent and Dependent Observations

    OpenAIRE

    M. G. Genton; Lucas, A.

    2000-01-01

    We provide a new definition of breakdown in finite samples with an extension to asymptotic breakdown. Previous definitions center around defining a critical region for either the parameter or the objective function. If for a particular outlier constellation the critical region is entered, breakdown is said to occur. In contract to the traditional approach, we leave the definition of the critical region implicit. Our definition encompasses all previousdefinitions of breakdown in both linear an...

  9. A severe form of breakdown in communication in the psychoanalysis of an ill adolescent.

    Science.gov (United States)

    Kennedy, R

    1990-01-01

    The paper focuses on a particularly severe kind of breakdown in communication that can arise in the psychoanalysis of ill adolescents who have experienced a real breakdown in functioning, such as a severe suicide attempt or one or more psychotic breakdowns. Clinical material is presented from the analysis of a suicidal and self-mutilating adolescent as an illustration of the theme. Included is a discussion of different types of breakdown in communication. PMID:2365550

  10. Effect of diet quality on mussel biomarker responses to pollutants.

    Science.gov (United States)

    González-Fernández, Carmen; Lacroix, Camille; Paul-Pont, Ika; Le Grand, Fabienne; Albentosa, Marina; Bellas, Juan; Viñas, Lucía; Campillo, Juan A; Hegaret, Helene; Soudant, Philippe

    2016-08-01

    The effect of the quality of two microalgal species on select biological and biochemical responses used as indicators of pollution were assessed. Mussels were conditioned for 6 weeks with the diatom Chaetoceros neogracile and the dinoflagellate Heterocapsa triquetra, chosen for being two clearly different types of primary production quality that differ in both biometric and biochemical characteristics. After dietary conditioning, the mussels were exposed to a polycyclic aromatic hydrocarbon, fluoranthene (FLU), for 1 week followed by 1 week of depuration. Results showed higher FLU accumulation in mussels fed on C. neogracile compared to those fed on H. triquetra. Concomitantly, a greater impact of this toxicant was observed in the biomarker responses of mussels fed on C. neogracile. These mussels showed an increase in the percentage of dead hemocytes, an activation of phagocytosis and ROS production of hemocytes after exposure. Some enzymatic activities also increased upon FLU exposure (superoxide dismutase -SOD-, catalase -CAT-, and glutathione reductases -GR-) and after depuration (glutathione-s-transferase -GST-). Results suggest that FLU exposure as well as food quality influence biomarker responses, with higher values of SOD, CAT and GR in non-exposed mussels fed on C. neogracile. In addition, upon exposure to the same FLU concentration, GR response varied according to dietary conditioning, suggesting that diet could act as a confounding factor in biomarker responses to pollution. Consequently, trophic conditions should be considered in marine pollution monitoring programs for a better interpretation of biomarker responses. PMID:27300503

  11. Breakdown characteristics in DC spark experiments of copper focusing on purity and hardness

    International Nuclear Information System (INIS)

    To investigate the breakdown characteristic of differences in purity and hardness, three samples of copper, oxygen-free copper (OFC), 7-nine large-grain copper and 6-nine hot-isotropic-pressed copper, were tested with the DC spark system at CERN. Measurements of beta, breakdown fields and breakdown probability are presented in this paper. (author)

  12. Differential saliva-induced breakdown of starch filled protein gels in relation to sensory perception

    NARCIS (Netherlands)

    Janssen, A.M.; Pijpekamp, A.M. van de; Labiausse, D.

    2009-01-01

    In this study, the differential breakdown of protein gels containing four types of high and low cross-linked starch granules were studied. Susceptibility to saliva-induced breakdown of starch granules and the consequences of these for overall breakdown of the gel matrix were captured using a multipl

  13. Calculation of Spark Breakdown or Corona Starting Voltages in Nonuniform Fields

    DEFF Research Database (Denmark)

    Pedersen, A.

    1967-01-01

    The processes leading to a spark breakdown or corona discharge are discussed very briefly. A quantitative breakdown criterion for use in high-voltage design is derived by which spark breakdown or corona starting voltages in nonuniform fields can be calculated. The criterion is applied to the sphere...

  14. Breakdown of plastics and polymers by microorganisms.

    Science.gov (United States)

    Kawai, F

    1995-01-01

    The interest in environmental issues is still growing and there are increasing demands to develop materials which do not burden the environment significantly. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. Biodegradation is necessary for water-soluble or water-miscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires both biochemical insight and understanding of the interactions between materials and microorganisms. It is now widely requested that polymeric materials come from renewable resources instead of petrochemical sources. The microbial production of polymeric and oligomeric materials is also described. PMID:7484358

  15. Meeting Report--NASA Radiation Biomarker Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Straume, Tore; Amundson, Sally A,; Blakely, William F.; Burns, Frederic J.; Chen, Allen; Dainiak, Nicholas; Franklin, Stephen; Leary, Julie A.; Loftus, David J.; Morgan, William F.; Pellmar, Terry C.; Stolc, Viktor; Turteltaub, Kenneth W.; Vaughan, Andrew T.; Vijayakumar, Srinivasan; Wyrobek, Andrew J.

    2008-05-01

    A summary is provided of presentations and discussions from the NASA Radiation Biomarker Workshop held September 27-28, 2007, at NASA Ames Research Center in Mountain View, California. Invited speakers were distinguished scientists representing key sectors of the radiation research community. Speakers addressed recent developments in the biomarker and biotechnology fields that may provide new opportunities for health-related assessment of radiation-exposed individuals, including for long-duration space travel. Topics discussed include the space radiation environment, biomarkers of radiation sensitivity and individual susceptibility, molecular signatures of low-dose responses, multivariate analysis of gene expression, biomarkers in biodefense, biomarkers in radiation oncology, biomarkers and triage following large-scale radiological incidents, integrated and multiple biomarker approaches, advances in whole-genome tiling arrays, advances in mass-spectrometry proteomics, radiation biodosimetry for estimation of cancer risk in a rat skin model, and confounding factors. Summary conclusions are provided at the end of the report.

  16. Oral Fluids that Detect Cardiovascular Disease Biomarkers

    Science.gov (United States)

    Foley, Joseph D.; Sneed, J. Darrell; Steinhubl, Steven R; Kolasa, Justin; Ebersole, Jeffrey L.; Lin, Yushun; Kryscio, Richard J.; McDevitt, John T.; Campbell, Charles L.; Miller, Craig S.

    2013-01-01

    Objective To determine the utility of oral fluids for assessment of coronary and cardiovascular (CVD) health. Study Design Twenty-nine patients with pre-existing CVD disease underwent an invasive cardiac procedure (alcohol septal ablation or percutaneous coronary intervention) and provided unstimulated whole saliva (UWS), sublingual swabs (LS), gingival swabs (GS) and serum at 0, 8, 16, 24, 48 hr. Concentrations of 13 relevant biomarkers were determined and correlated with levels in serum and the oral fluids. Results Concentrations of the majority of biomarkers were higher in UWS than LS and GS. Coronary and CVD disease biomarkers in UWS correlated better with serum than LS and GS based on group status and measures of time effect. Seven biomarkers demonstrated time effect changes consistent with serum biomarkers, including C-reactive protein and troponin I. Conclusions Changes in serum biomarker profiles are reflected in oral fluids suggesting that oral fluid biomarkers could aid in the assessment of cardiac ischemia/necrosis. PMID:22769406

  17. Laser-induced breakdown emission in hydrocarbon fuel mixtures

    Science.gov (United States)

    Kobayashi, Kazunobu; Bak, Moon Soo; Tanaka, Hiroki; Carter, Campbell; Do, Hyungrok

    2016-04-01

    Time-resolved emission measurements of laser-induced breakdown plasmas have been carried out to investigate the effect that gas species might have on the kinetics, particularly in excited states, and the resulting plasma properties. For this purpose, fuel-oxygen (O2)-carbon dioxide (CO2) mixtures with either helium (He) or nitrogen (N2) balance are prepared while maintaining their atomic compositions. The fuels tested in this study are methane (CH4), ethylene (C2H4), propane (C3H8), and butane (C4H10). The breakdown is produced in the mixtures (CH4/CO2/O2/He, C2H4/O2/He, C3H8/CO2/O2/He and C4H10/CO2/O2/He or CH4/CO2/O2/N2, C2H4/O2/N2, C3H8/CO2/O2/N2 and C4H10/CO2/O2/N2) at room conditions using the second harmonic of a Q-switched Nd:YAG laser (with pulse duration of 10 ns). The temporal evolution of plasma temperature is deduced from the ratio of two oxygen lines (777 nm and 823 nm) through Boltzmann analysis, while the evolution of electron number density is estimated based on Stark broadening of the Balmer-alpha (H α ) line at 656 nm and the measured plasma temperature. From the results, the temporal evolution of emission spectra and decay rates of atomic line-intensities are found to be almost identical between the breakdown plasma in the different mixtures given balancing gases. Furthermore, the temporal evolution of plasma temperature and electron number density are also found to be independent of the species compositions. Therefore, this behavior—of the breakdown emissions and plasma properties in the different mixtures with identical atomic composition—may be because the breakdown gases reach similar thermodynamic and physiochemical states immediately after the breakdown.

  18. Biomarkers in acute lung injury.

    Science.gov (United States)

    Mokra, Daniela; Kosutova, Petra

    2015-04-01

    Acute respiratory distress syndrome (ARDS) and its milder form acute lung injury (ALI) may result from various diseases and situations including sepsis, pneumonia, trauma, acute pancreatitis, aspiration of gastric contents, near-drowning etc. ALI/ARDS is characterized by diffuse alveolar injury, lung edema formation, neutrophil-derived inflammation, and surfactant dysfunction. Clinically, ALI/ARDS is manifested by decreased lung compliance, severe hypoxemia, and bilateral pulmonary infiltrates. Severity and further characteristics of ALI/ARDS may be detected by biomarkers in the plasma and bronchoalveolar lavage fluid (or tracheal aspirate) of patients. Changed concentrations of individual markers may suggest injury or activation of the specific types of lung cells-epithelial or endothelial cells, neutrophils, macrophages, etc.), and thereby help in diagnostics and in evaluation of the patient's clinical status and the treatment efficacy. This chapter reviews various biomarkers of acute lung injury and evaluates their usefulness in diagnostics and prognostication of ALI/ARDS.

  19. Genetic biomarkers in hypertrophic cardiomyopathy.

    Science.gov (United States)

    Coats, Caroline J; Elliott, Perry M

    2013-08-01

    Hypertrophic cardiomyopathy is a common inherited heart muscle disorder associated with sudden cardiac death, arrhythmias and heart failure. Genetic mutations can be identified in approximately 60% of patients; these are commonest in genes that encode proteins of the cardiac sarcomere. Similar to other Mendelian diseases these mutations are characterized by incomplete penetrance and variable clinical expression. Our knowledge of this genetic diversity is rapidly evolving as high-throughput DNA sequencing technology is now used to characterize an individual patient's disease. In addition, the genomic basis of several multisystem diseases associated with a hypertrophic cardiomyopathy phenotype has been elucidated. Genetic biomarkers can be helpful in making an accurate diagnosis and in identifying relatives at risk of developing the condition. In the clinical setting, genetic testing and genetic screening should be used pragmatically with appropriate counseling. Here we review the current role of genetic biomarkers in hypertrophic cardiomyopathy, highlight recent progress in the field and discuss future challenges.

  20. Glycoscience aids in biomarker discovery

    Directory of Open Access Journals (Sweden)

    Serenus Hua1,2 & Hyun Joo An1,2,*

    2012-06-01

    Full Text Available The glycome consists of all glycans (or carbohydrates within abiological system, and modulates a wide range of important biologicalactivities, from protein folding to cellular communications.The mining of the glycome for disease markers representsa new paradigm for biomarker discovery; however, this effortis severely complicated by the vast complexity and structuraldiversity of glycans. This review summarizes recent developmentsin analytical technology and methodology as applied tothe fields of glycomics and glycoproteomics. Mass spectrometricstrategies for glycan compositional profiling are described, as arepotential refinements which allow structure-specific profiling.Analytical methods that can discern protein glycosylation at aspecific site of modification are also discussed in detail.Biomarker discovery applications are shown at each level ofanalysis, highlighting the key role that glycoscience can play inhelping scientists understand disease biology.

  1. Chronic Obstructive Pulmonary Disease Biomarkers

    Directory of Open Access Journals (Sweden)

    Tatsiana Beiko

    2016-04-01

    Full Text Available Despite significant decreases in morbidity and mortality of cardiovascular diseases (CVD and cancers, morbidity and cost associated with chronic obstructive pulmonary disease (COPD continue to be increasing. Failure to improve disease outcomes has been related to the paucity of interventions improving survival. Insidious onset and slow progression halter research successes in developing disease-modifying therapies. In part, the difficulty in finding new therapies is because of the extreme heterogeneity within recognized COPD phenotypes. Novel biomarkers are necessary to help understand the natural history and pathogenesis of the different COPD subtypes. A more accurate phenotyping and the ability to assess the therapeutic response to new interventions and pharmaceutical agents may improve the statistical power of longitudinal clinical studies. In this study, we will review known candidate biomarkers for COPD, proposed pathways of pathogenesis, and future directions in the field.

  2. A Study of Dielectric Breakdown Along Insulators Surrounding Conductors in Liquid Argon

    CERN Document Server

    Lockwitz, Sarah

    2015-01-01

    High voltage breakdown in liquid argon is an important consideration in the design of liquid argon time projection chambers, which are often used as neutrino and dark matter detectors. We have made systematic measurements of breakdown voltages in liquid argon along insulators surrounding negative rod electrodes. The purpose of these tests is to understand the effects of materials, of breakdown path length, and of surface topology. We have found no material-specific effects other than those due to their permittivity. We have found no dependence on breakdown voltage on the length of the exposed insulator. A model for the breakdown mechanism is presented that can help inform future designs.

  3. Finding good biomarkers for sarcopenia

    OpenAIRE

    Scharf, Gesine; Heineke, Joerg

    2012-01-01

    The term sarcopenia describes the age-related loss of skeletal muscle mass and function. While this process, in principal, occurs in every adult person and already starts around the age of 40, it is associated with disability, morbidity, and increased mortality in some individuals. In the absence of clear clinical manifestation, we today lack the ability to differentiate between physiological and pathological sarcopenia. In this regard, we need good biomarkers that can be quantified in a reli...

  4. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, Jodi Kirsten

    2013-01-01

    Background: Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT-proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been as extensively investigated in hyperthyroidism.Hypothesis: Plasma NT-proBNP and cTNI concentrations are higher in cats with primary cardiac disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats.Animals: Twenty-three hyperthyr...

  5. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, J.K.; Panciera, D L; Abbott, J.A.; Zimmerman, K.C.; Lantis, A.C.

    2013-01-01

    Background Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT‐proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been extensively investigated in hyperthyroidism. Hypothesis Plasma NT‐proBNP and cTNI concentrations are higher in cats with primary myocardial disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats. Animals Twenty‐three hyperthyro...

  6. Proteomics Discovery of Disease Biomarkers

    OpenAIRE

    Mamoun Ahram; Petricoin, Emanuel F.

    2008-01-01

    Recent technological developments in proteomics have shown promising initiatives in identifying novel biomarkers of various diseases. Such technologies are capable of investigating multiple samples and generating large amount of data end-points. Examples of two promising proteomics technologies are mass spectrometry, including an instrument based on surface enhanced laser desorption/ionization, and protein microarrays. Proteomics data must, however, undergo analytical processing using bioinfo...

  7. Physical mechanism of progressive breakdown in gate oxides

    Science.gov (United States)

    Palumbo, Felix; Lombardo, Salvatore; Eizenberg, Moshe

    2014-06-01

    The definition of the basic physical mechanisms of the dielectric breakdown (BD) phenomenon is still an open area of research. In particular, in advanced complementary metal-oxide-semiconductor (CMOS) circuits, the BD of gate dielectrics occurs in the regime of relatively low voltage and very high electric field; this is of enormous technological importance, and thus widely investigated but still not well understood. Such BD is characterized by a gradual, progressive growth of the gate leakage through a localized BD spot. In this paper, we report for the first time experimental data and a model which provide understanding of the main physical mechanism responsible for the progressive BD growth. We demonstrate the ability to control the breakdown growth rate of a number of gate dielectrics and provide a physical model of the observed behavior, allowing to considerably improve the reliability margins of CMOS circuits by choosing a correct combination of voltage, thickness, and thermal conductivity of the gate dielectric.

  8. Critical effects of downstream boundary conditions on vortex breakdown

    Science.gov (United States)

    Kandil, Osama; Kandil, Hamdy A.; Liu, C. H.

    1992-01-01

    The unsteady, compressible, full Navier-Stokes (NS) equations are used to study the critical effects of the downstream boundary conditions on the supersonic vortex breakdown. The present study is applied to two supersonic vortex breakdown cases. In the first case, quasi-axisymmetric supersonic swirling flow is considered in a configured circular duct, and in the second case, quasi-axisymmetric supersonic swirling jet, that is issued from a nozzle into a supersonic jet of lower Mach number, is considered. For the configured duct flow, four different types of downstream boundary conditions are used, and for the swirling jet flow from the nozzle, two types of downstream boundary conditions are used. The solutions are time accurate which are obtained using an implicit, upwind, flux-difference splitting, finite-volume scheme.

  9. Relativistic runaway breakdown in low-frequency radio

    DEFF Research Database (Denmark)

    Fullekrug, M.; Roussel-Dupre, R.; Symbalisty, E.M.D.;

    2011-01-01

    The electromagnetic radiation emitted by an electron avalanche beam resulting from relativistic runaway breakdown within the Earth's atmosphere is investigated. It is found from theoretical modeling with a computer simulation that the electron beam emits electromagnetic radiation which...... at a distance of similar to 550 km. The measured broadband pulses occur similar to 4-9 ms after the sprite-producing lightning discharge, they exhibit electromagnetic radiation which mainly spans the frequency range from similar to 50 to 350 kHz, and they exhibit complex waveforms without the typical...... electromagnetic pulses and possibly generates sprites. The source location of the broadband pulses can be determined with an interferometric network of wideband low-frequency radio receivers to lend further experimental support to the relativistic runaway breakdown theory....

  10. Boron nitride as two dimensional dielectric: Reliability and dielectric breakdown

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yanfeng; Pan, Chengbin; Hui, Fei; Shi, Yuanyuan; Lanza, Mario, E-mail: mlanza@suda.edu.cn [Institute of Functional Nano and Soft Materials, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, 199 Ren-Ai Road, Suzhou 215123 (China); Zhang, Meiyun; Long, Shibing [Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Lian, Xiaojuan; Miao, Feng [National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Larcher, Luca [DISMI, Università di Modena e Reggio Emilia, 42122 Reggio Emilia (Italy); Wu, Ernest [IBM Research Division, Essex Junction, Vermont 05452 (United States)

    2016-01-04

    Boron Nitride (BN) is a two dimensional insulator with excellent chemical, thermal, mechanical, and optical properties, which make it especially attractive for logic device applications. Nevertheless, its insulating properties and reliability as a dielectric material have never been analyzed in-depth. Here, we present the first thorough characterization of BN as dielectric film using nanoscale and device level experiments complementing with theoretical study. Our results reveal that BN is extremely stable against voltage stress, and it does not show the reliability problems related to conventional dielectrics like HfO{sub 2}, such as charge trapping and detrapping, stress induced leakage current, and untimely dielectric breakdown. Moreover, we observe a unique layer-by-layer dielectric breakdown, both at the nanoscale and device level. These findings may be of interest for many materials scientists and could open a new pathway towards two dimensional logic device applications.

  11. Possibility of increasing the optical breakdown threshold in KDP crystals

    International Nuclear Information System (INIS)

    The effect of various technological factors like the direction of crystal growth [(100) or (101)], acidity of the mother solution, growth rate, degree of filtration of the mother solution, purity of the starting raw material, specially introduced impurity (Pb), as well as after-growth thermal annealing, on the optical breakdown threshold of KDP crystals grown by the technique of rapid growth of profiled crystals is studied. It is shown that by using initial high-purity salts and fine filtration of solutions followed by after-growth annealing, it is possible to increase the optical breakdown threshold of profiled rapidly grown KDP crystals to values corresponding to the requirements of modern laser designs. (laser devices and elements)

  12. Risky business: Preventing skin breakdown in children with spina bifida.

    Science.gov (United States)

    Ekmark, Elaine McGarr

    2009-01-01

    The purpose of this article is to provide an overview of skin issues in children with spina bifida. Included in the discussion below is a review of the etiology of pressure ulcers and the updated 2007 pressure ulcer definition and pressure ulcer staging system as defined by the National Pressure Ulcer Advisory Panel (NPUAP). Pediatric risk factors for skin breakdown are presented including risk factors unique to children with spina bifida. Pediatric pressure ulcer risk assessment scales are described. The 5 Million Lives Kids' Campaign which has a focus on preventing hospital-acquired pressure ulcers in children is also reviewed along with evidence based prevention strategies. The key to preventing skin breakdown and pressure ulcers in children with spina bifida is early identification of the child's individual risk factors so that a prevention protocol can be implemented in all settings: hospital, home and the community. Options for wound management, dressing selection and pain management are included. PMID:21791793

  13. Breakdown and defect generation in ultrathin gate oxide

    Science.gov (United States)

    Depas, M.; Vermeire, B.; Heyns, M. M.

    1996-07-01

    In this work the dielectric reliability of thermally grown ultrathin 3 nm SiO2 layers in poly-Si/SiO2/Si structures is examined. This is compared with a study of the defect generation in the 3 nm gate oxide during tunnel injection of electrons. In these ultrathin SiO2 layers, direct tunneling of electrons becomes very important. An increase of the direct tunnel and Fowler-Nordheim tunnel current during high-field stressing was observed and is explained by the creation of a positive charge in the oxide associated with slow interface traps. It is demonstrated that a higher current instability corresponds with a lower charge to breakdown value (QBD) of the oxide. From these results we conclude that the creation of slow interface traps is an important precursor effect for the 3 nm gate oxide breakdown.

  14. Electrical Breakdown and Mechanical Ageing in Dielectric Elastomers

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin

    reported to increase the breakdown strength of DEs such as compositing and pre-stretching. Some of the techniques, however, affect other parameters related to DEs negatively. For instance, the elastomers with hard filler particles (e.g. metal oxides) used as DEs experience difficulties to maintain......, the lifetime of elastomer materials needs further investigation. Therefore, in the second strategy, several DE parameters such as Young’s moduli, breakdown strengths and dielectric permittivities of PDMS elastomers filled with hard filler particles were investigated after being subjected to pre......-stretching for various timespans. The study showed that electromechanical reliability when pre-stretching was difficult to achieve with PDMS elastomers filled with hard filler particles. Subsequently, the long-term mechanical and electrical reliability was further investigated to the PDMS elastomers filled with the soft...

  15. Gas breakdown and plasma impedance in split-ring resonators

    Science.gov (United States)

    Hoskinson, Alan R.; Parsons, Stephen; Hopwood, Jeffrey

    2016-02-01

    The appearance of resonant structures in metamaterials coupled to plasmas motivates the systematic investigation of gas breakdown and plasma impedance in split-ring resonators over a frequency range of 0.5-9 GHz. In co-planar electrode gaps of 100 μm, the breakdown voltage amplitude decreases from 280 V to 225 V over this frequency range in atmospheric argon. At the highest frequency, a microplasma can be sustained using only 2 mW of power. At 20 mW, we measure a central electron density of 2 × 1020 m-3. The plasma-electrode overlap plays a key role in the microplasma impedance and causes the sheath impedance to dominate the plasma resistance at very low power levels. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  16. Analysis of organic vapors with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

  17. High voltage breakdown in an inductively coupled ion source

    International Nuclear Information System (INIS)

    An inductively coupled plasma source, designed for ion beam applications, is allowed to float up to several kilovolt positive. If one side of the radio frequency (rf) antenna is grounded and the dielectric source tube and the surrounding air are allowed to reach a threshold temperature corona breakdown at the rf antenna occurs. The experiments presented here show that a dc corona can be ignited with the presence of a dielectric barrier, which normally precludes dc breakdown. The formation of a negative barrier corona initiates a transition to a continuous arc from the rf antenna to the source tube. It is suggested that the onset of the first filaments heat the dielectric locally, such that the dielectric strength drops. DC current channels are then formed in the source tube, allowing a resistive corona with continuous arcs to exist

  18. Erythropoietin retards DNA breakdown and prevents programmed death in erythroid progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Koury, M.J.; Bondurant, M.C. (Vanderbilt Univ. Medical Center, Nashville, TN (USA) Veterans Administration Medical Center, Nashville, TN (USA))

    1990-04-20

    The mechanism by which erythropoietin controls mammalian erythrocyte production is unknown. Labeling experiments in vitro with ({sup 3}H) thymidine demonstrated DNA cleavage in erythroid progenitor cells that was accompanied by DNA repair and synthesis. Erythropoietin reduced DNA cleavage by a factor of 2.6. In the absence of erythropoietin, erythroid progenitor cells accumulated DNA cleavage fragments characteristic of those found in programmed cell death (apoptosis) by 2 to 4 hours and began dying by 16 hours. In the presence of erythropoietin, the progenitor cells survived and differentiated into reticulocytes. Thus, apoptosis is a major component of normal erythropoiesis, and erythropoietin controls erythrocyte production by retarding DNA breakdown and preventing apoptosis in erythroid progenitor cells.

  19. Financial market breakdown due to strategy constraints and information asymmetry

    OpenAIRE

    Hu, Jie

    1995-01-01

    This paper demonstrates the relevance of strategy constraints on market makers to the possibility of financial market breakdown when there is information asymmetry between market makers and investors; both the case of competitive market makers and the case of a monopolistic market marker are included. Specifically, the paper discusses three types of strategy constraints on the market makers and their implications for the equilibria. The results call attention to the need for more precise spec...

  20. DC breakdown field measurements of heat treated molybdenum

    CERN Document Server

    Calatroni, Sergio; Ramsvik, T; Taborelli, M; CERN. Geneva. TS Department

    2008-01-01

    The effect of heat treatments of molybdenum on the resistance to breakdown and conditioning speed has been investigated in the DC spark setup. The conditioning speed is strongly improved by treatment at 875C in UHV ex situ compared to chemically cleaned surfaces. This temperature is sufficiently low to prevent a re-crystallization of the material which could influence mechanical properties, as hardness. The saturation field remains unchanged. The beneficial effect is preserved for 8 h of air exposure after treatment.

  1. Simulation of Ion Generation and Breakdown in Atmospheric Air

    OpenAIRE

    Zhang, W; Fisher, T. S.; Garimella, S V

    2004-01-01

    Understanding of ion generation in air provides insights to several applications, such as gas sensors, electrohydrodynamic pumping, and air purification. In this paper, ion generation processes in atmospheric air are simulated using a particle-in-cell and Monte Carlo method with emphasis on the prediction of ion generation and breakdown characteristics in microscale gaps. The simulation results are validated through comparison to Townsend’s discharge theory and experiments. The significance o...

  2. Breakdown of cell-collagen networks through collagen remodeling

    OpenAIRE

    Iordan, Andreea; Duperray, Alain; Gérard, Anaïs; Grichine, Alexei; Verdier, Claude

    2010-01-01

    International audience Collagen model tissues are analyzed, which consist of cells embedded in a collagen matrix at different concentrations (of cells and collagen). Rheological properties are measured and complementary confocal microscopy analyses are carried out. An important feature is observed, corresponding to the breakdown of the collagen network (i.e. decrease in network elasticity) for high collagen concentrations, due to the presence of cells. Thanks to confocal microscopy, we sho...

  3. Time-resolved laser-induced breakdown spectroscopy of aluminum

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-yun; ZHANG Wei-jun; WANG Zhen-ya; HAO Li-qing; HUANG Ming-qiang; ZHAO Wen-wu; LONG Bo; Zhao Wei

    2008-01-01

    We develop a system to measure the elemental composition of unprepared samples using laser-induced breakdown spectroscopy (LIBS) in our laboratory, which can be used for the determination of elements in solids, liquids and aerosols. A description of the instrumentation, including laser, sample chamber and detection, is followed by a brief discussion. The time-resolved LIBS of aluminum at atmospheric pressure is presented. At the end, the possibilities and later uses of this technique are briefly discussed.

  4. Breakdown of an Inhomogeneous Scale- Free Network Under Intentional Attack

    Institute of Scientific and Technical Information of China (English)

    LIN Guo-Ji; CHENG Xiang; OU-YANG Qi

    2003-01-01

    Using a recently introduced network model with node and connection diversity, we study the breakdown of different scale-free networks under intentional attacks. Our simulation results show that inhomogeneous networks are more sensitive to intentional attack than the homogeneous ones and that the centralization of the networks is an important variable, reflecting the characteristics of the network under intentional attack. Using a recently introduced method we can theoretically develop the critical point of the inhomogeneous networks.

  5. Ionizing gas breakdown waves in strong electric fields.

    Science.gov (United States)

    Klingbeil, R.; Tidman, D. A.; Fernsler, R. F.

    1972-01-01

    A previous analysis by Albright and Tidman (1972) of the structure of an ionizing potential wave driven through a dense gas by a strong electric field is extended to include atomic structure details of the background atoms and radiative effects, especially, photoionization. It is found that photoionization plays an important role in avalanche propagation. Velocities, electron densities, and temperatures are presented as a function of electric field for both negative and positive breakdown waves in nitrogen.

  6. The Proactive International Dimension and the Breakdown of Authoritarian Regimes

    OpenAIRE

    Castaldo, Antonino

    2016-01-01

    There is international consensus among scholars that democratic transitions are multicausal processes in which both internal and international variables are involved (Pridham 1991, 1995; Whitehead 1996; Schmitter 1996; Linz and Stepan 1996; Carothers 1999; Morlino and Magen 2008; Grilli di Cortona 2009). This chapter is limited, on the one hand, to the dependent variable consisting solely of the crisis/breakdown/transformation of non-democratic regimes in the Third Wave o...

  7. The role of trust in communication breakdowns in disaster situations

    OpenAIRE

    Scholander, Robert

    2008-01-01

    Disaster situations are, by their very nature, broad and complex situations. While it is intrinsically appealing to assume that communication breakdowns in these situations are due to technological barriers, this assumption overlooks the possibility that non-technological barriers to communication exist within and between agencies and individuals. High levels of social capital within or between groups will enable better communication and resource flows. Thus trust will clearly have a critical...

  8. Dietary biomarkers: advances, limitations and future directions

    Directory of Open Access Journals (Sweden)

    Hedrick Valisa E

    2012-12-01

    Full Text Available Abstract The subjective nature of self-reported dietary intake assessment methods presents numerous challenges to obtaining accurate dietary intake and nutritional status. This limitation can be overcome by the use of dietary biomarkers, which are able to objectively assess dietary consumption (or exposure without the bias of self-reported dietary intake errors. The need for dietary biomarkers was addressed by the Institute of Medicine, who recognized the lack of nutritional biomarkers as a knowledge gap requiring future research. The purpose of this article is to review existing literature on currently available dietary biomarkers, including novel biomarkers of specific foods and dietary components, and assess the validity, reliability and sensitivity of the markers. This review revealed several biomarkers in need of additional validation research; research is also needed to produce sensitive, specific, cost-effective and noninvasive dietary biomarkers. The emerging field of metabolomics may help to advance the development of food/nutrient biomarkers, yet advances in food metabolome databases are needed. The availability of biomarkers that estimate intake of specific foods and dietary components could greatly enhance nutritional research targeting compliance to national recommendations as well as direct associations with disease outcomes. More research is necessary to refine existing biomarkers by accounting for confounding factors, to establish new indicators of specific food intake, and to develop techniques that are cost-effective, noninvasive, rapid and accurate measures of nutritional status.

  9. Relativistic runaway breakdown in low-frequency radio

    Science.gov (United States)

    Füllekrug, Martin; Roussel-Dupré, Robert; Symbalisty, Eugene M. D.; Chanrion, Olivier; Odzimek, Anna; van der Velde, Oscar; Neubert, Torsten

    2010-01-01

    The electromagnetic radiation emitted by an electron avalanche beam resulting from relativistic runaway breakdown within the Earth's atmosphere is investigated. It is found from theoretical modeling with a computer simulation that the electron beam emits electromagnetic radiation which is characterized by consecutive broadband pulses in the low-frequency radio range from ˜10 to 300 kHz at a distance of ˜800 km. Experimental evidence for the existence of consecutive broadband pulses is provided by low-frequency radio observations of sprite-producing lightning discharges at a distance of ˜550 km. The measured broadband pulses occur ˜4-9 ms after the sprite-producing lightning discharge, they exhibit electromagnetic radiation which mainly spans the frequency range from ˜50 to 350 kHz, and they exhibit complex waveforms without the typical ionospheric reflection of the first hop sky wave. Two consecutive pulses occur ˜4.5 ms and ˜3 ms after the causative lightning discharge and coincide with the sprite luminosity. It is concluded that relativistic runaway breakdown within the Earth's atmosphere can emit broadband electromagnetic pulses and possibly generates sprites. The source location of the broadband pulses can be determined with an interferometric network of wideband low-frequency radio receivers to lend further experimental support to the relativistic runaway breakdown theory.

  10. Pre breakdown Field Emission of Micro metric Vacuum Gaps under DC Voltage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Dal [Kyungnam University (Korea, Republic of); Lee, Sae Hun [Daewon Junior College (Korea, Republic of)

    1997-04-30

    Vacuum breakdown is initiated by pre breakdown phenomena. Among the most important pre breakdown phenomena, We can distinguish Metallic Field Electron Emission and Micro Discharge. The electrical breakdown characteristics of uniform field gap in vacuum showed that the pre breakdown current flowing the electrodes was dependent on field and could be described by the Fowler Nordheim equation. This paper gives an account of an experimental investigation of the pre breakdown current, micro gaps 20, 50, 75, 100[{mu}m] consisting of stainless steel electrodes at pressure 760, 1.2 x 10{sup -3}, 1.2 x 10{sup -5}[torr]. The I-V characteristic curves obtained for various gaps and pressure were analyzed according to Fowler-Nordheim field emission theory. Finally, electrical breakdown mechanism of micro gap in vacuum is depend on metallic emission(M-FEE). (author). 10 refs., 13 figs., 1 tab.

  11. Dielectric breakdown of MXB-71 phenolic and Sylgard 184/GMB silicone at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.T. Jr.; Beeson, P.M.

    1983-07-01

    High temperature electrical breakdown characteristics have been determined for MXB-71 phenolic and Sylgard 184/GMB silicone in air and nitrogen environments. The phenolic material is used for electronic case housings whereas the silicone is an encapsulant. The experiments were performed with constant electric fields (values ranging from 3 x 10/sup 3/ to 2.5 x 10/sup 4/ V/cm) applied to the samples while the temperature was increased at a rate of 10/sup 0/C/minute. The sample current until breakdown was determined. Results showed that breakdown occurred between 470 to 725/sup 0/C, and was principally dependent upon the material conductivity at time breakdown and the electric field. The breakdown temperature decreased with increasing electric field and decreased in an oxygen-containing environment. Materials postcured at 580 to 600/sup 0/C prior to electrical testing exhibited considerably lower breakdown temperatures at higher electric fields. Results suggest that breakdown occurred via thermal runaway.

  12. Eye-safe infrared laser-induced breakdown spectroscopy (LIBS) emissions from energetic materials

    Science.gov (United States)

    Brown, Ei E.; Hömmerich, Uwe; Yang, Clayton C.; Jin, Feng; Trivedi, Sudhir B.; Samuels, Alan C.

    2016-05-01

    Laser-induced breakdown spectroscopy is a powerful diagnostic tool for detection of trace elements by monitoring the atomic and ionic emission from laser-induced plasmas. Besides elemental emissions from conventional UV-Vis LIBS, molecular LIBS emission signatures of the target compounds were observed in the long-wave infrared (LWIR) region in recent studies. Most current LIBS studies employ the fundamental Nd:YAG laser output at 1.064 μm, which has extremely low eye-damage threshold. In this work, comparative LWIR-LIBS emissions studies using traditional 1.064 μm pumping and eye-safe laser wavelength at 1.574 μm were performed on several energetic materials for applications in chemical, biological, and explosive (CBE) sensing. A Q-switched Nd: YAG laser operating at 1.064 μm and the 1.574 μm output of a pulsed Nd:YAG pumped Optical Parametric Oscillator were employed as the excitation sources. The investigated energetic materials were studied for the appearance of LWIR-LIBS emissions (4-12 μm) that are directly indicative of oxygenated breakdown products as well as partially dissociated and recombination molecular species. The observed molecular IR LIBS emission bands showed strong correlation with FTIR absorption spectra of the studied materials for 1.064 μm and 1.574 μm pump wavelengths.

  13. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    International Nuclear Information System (INIS)

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: ► We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. ► We used water jet setup, bulk liquid arrangement and algal biofilms. ► LIBS analysis of macro- and micro-element concentrations in algae was shown. ► LIBS can be of assistance in research of sustainable biofuel generation. ► LIBS can be used in research of algal food applications and bioremediation.

  14. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Porizka, P.; Prochazka, D. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Pilat, Z. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Krajcarova, L. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Kaiser, J., E-mail: kaiser@fme.vutbr.cz [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Malina, R.; Novotny, J. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Zemanek, P.; Jezek, J.; Sery, M.; Bernatova, S.; Krzyzanek, V.; Dobranska, K. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Novotny, K. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Trtilek, M. [Photon Systems Instruments, Drasov 470, 664 24 Drasov (Czech Republic); Samek, O. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic)

    2012-08-15

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: Black-Right-Pointing-Pointer We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. Black-Right-Pointing-Pointer We used water jet setup, bulk liquid arrangement and algal biofilms. Black-Right-Pointing-Pointer LIBS analysis of macro- and micro-element concentrations in algae was shown. Black-Right-Pointing-Pointer LIBS can be of assistance in research of sustainable biofuel generation. Black-Right-Pointing-Pointer LIBS can be used in research of algal food applications and bioremediation.

  15. Characterization of hard coatings produced by laser cladding using laser-induced breakdown spectroscopy technique

    Energy Technology Data Exchange (ETDEWEB)

    Varela, J.A.; Amado, J.M.; Tobar, M.J.; Mateo, M.P.; Yañez, A.; Nicolas, G., E-mail: gines@udc.es

    2015-05-01

    Highlights: • Chemical mapping and profiling by laser-induced breakdown spectroscopy (LIBS) of coatings produced by laser cladding. • Production of laser clads using tungsten carbide (WC) and nickel based matrix (NiCrBSi) powders. • Calibration by LIBS of hardfacing alloys with different WC concentrations. - Abstract: Protective coatings with a high abrasive wear resistance can be obtained from powders by laser cladding technique, in order to extend the service life of some industrial components. In this work, laser clad layers of self-fluxing NiCrBSi alloy powder mixed with WC powder have been produced on stainless steel substrates of austenitic type (AISI 304) in a first step and then chemically characterized by laser-induced breakdown spectroscopy (LIBS) technique. With the suitable laser processing parameters (mainly output power, beam scan speed and flow rate) and powders mixture proportions between WC ceramics and NiCrBSi alloys, dense pore free layers have been obtained on single tracks and on large areas with overlapped tracks. The results achieved by LIBS technique and applied for the first time to the analysis of laser clads provided the chemical composition of the tungsten carbides in metal alloy matrix. Different measurement modes (multiple point analyses, depth profiles and chemical maps) have been employed, demonstrating the usefulness of LIBS technique for the characterization of laser clads based on hardfacing alloys. The behavior of hardness can be explained by LIBS maps which evidenced the partial dilution of some WC spheres in the coating.

  16. Structures of chlorophyll catabolites in bananas (Musa acuminata) reveal a split path of chlorophyll breakdown in a ripening fruit.

    Science.gov (United States)

    Moser, Simone; Müller, Thomas; Holzinger, Andreas; Lütz, Cornelius; Kräutler, Bernhard

    2012-08-27

    The disappearance of chlorophyll is a visual sign of fruit ripening. Yet, chlorophyll breakdown in fruit has hardly been explored; its non-green degradation products are largely unknown. Here we report the analysis and structure elucidation of colorless tetrapyrrolic chlorophyll breakdown products in commercially available, ripening bananas (Musa acuminata, Cavendish cultivar). In banana peels, chlorophyll catabolites were found in an unprecedented structural richness: a variety of new fluorescent chlorophyll catabolites (FCCs) and nonfluorescent chlorophyll catabolites (NCCs) were detected. As a rule, FCCs exist only "fleetingly" and are hard to observe. However, in bananas several of the FCCs (named Mc-FCCs) were persistent and carried an ester function at the propionate side-chain. NCCs were less abundant, and exhibited a free propionic acid group, but functional modifications elsewhere. The modifications of NCCs in banana peels were similar to those found in NCCs from senescent leaves. They are presumed to be introduced by enzymatic transformations at the stage of the mostly unobserved, direct FCC-precursors. The observed divergent functional group characteristics of the Mc-FCCs versus those of the Mc-NCCs indicated two major "late" processing lines of chlorophyll breakdown in ripening bananas. The "last common precursor" at the branching point to either the persistent FCCs, or towards the NCCs, was identified as a temporarily abundant "secondary" FCC. The existence of two "downstream" branches of chlorophyll breakdown in banana peels, and the striking accumulation of persistent Mc-FCCs call for attention as to the still-elusive biological roles of the resulting colorless linear tetrapyrroles.

  17. Exosomal miRNAs as biomarkers for prostate cancer

    Directory of Open Access Journals (Sweden)

    Nina Pettersen Hessvik

    2013-03-01

    Full Text Available miRNAs are small non-coding RNAs that finely regulate gene expression in cells. Alterations in miRNA expression have been associated with development of cancer, and miRNAs are now being investigated as biomarkers for cancer as well as other diseases. Recently, miRNAs have been found outside cells in body fluids. Extracellular miRNAs exist in different forms - associated with Ago2 proteins, loaded into extracellular vesicles (exosomes, microvesicles or apoptotic bodies or into high density lipoprotein particles. These extracellular miRNAs are probably products of distinct cellular processes, and might therefore play different roles. However, their functions in vivo are currently unknown. In spite of this, they are considered as promising, noninvasive diagnostic and prognostic tools. Prostate cancer is the most common cancer in men in the Western world, but the currently used biomarker (prostate specific antigen has low specificity. Therefore, novel biomarkers are highly needed. In this review we will discuss possible biological functions of extracellular miRNAs, as well as the potential use of miRNAs from extracellular vesicles as biomarkers for prostate cancer.

  18. Biomarker discovery in systemic sclerosis: state of the art

    Directory of Open Access Journals (Sweden)

    Bonella F

    2015-07-01

    Full Text Available Francesco Bonella,1 Giuseppe Patuzzo,2 Claudio Lunardi2 1Interstitial and Rare Lung Disease Unit, Ruhrlandklinik University Hospital, University of Duisburg-Essen, Essen, Germany; 2Department of Medicine, University of Verona, Verona, Italy Abstract: Systemic sclerosis (SSc is an autoimmune disease characterized by immune dysfunction and by abnormalities of the microvasculature with vascular obliteration, eventually leading to fibrosis of the skin, gastrointestinal tract, lungs, heart, and kidney. The etiology and pathogenesis of SSc remain unclear, despite recent significant progress in the field. Immune activation and microangiopathy are followed by widespread organ fibrosis, leading to organ failure and increased mortality. The production of inflammatory cytokines and growth factors after tissue injury, as well as the presence of circulating autoantibodies, provide a source of biomarkers with potential diagnostic and prognostic applications in the clinical routine. Two principal approaches exist to discover and characterize biomarkers. The proof-of-concept approach verifies the ability of known proteins, generally involved in the pathogenesis, to correlate with disease phenotype and outcome. A proteomic approach does not need prior knowledge of the proteins or of their function, but it requires high-performance and time-consuming techniques. In this review, we highlight the most recent findings in biomarkers used to characterize SSc organ involvement, to stratify the patients, and to assess the response to treatment. Keywords: systemic sclerosis, biomarkers, proteomics, gene expression profiling

  19. Faecal biomarkers of intestinal health and disease in children

    Directory of Open Access Journals (Sweden)

    Tamara ePang

    2014-01-01

    Full Text Available The identification of various faecal biomarkers has provided insight into the intestinal milieu. Most of these markers are associated with the innate immune system of the gut, apart from the more novel M2-pyruvate kinase (M2-PK. The innate immunity of the gut plays a role in maintaining a fine balance between tolerance to commensal bacteria and immune response to potential pathogens. It is a complex system, which comprises of multiple elements, including antimicrobial peptides (e.g. defensins, cathelicidins, lactoferrin and osteoprotegerin, inflammatory proteins (e.g. calprotectin and S100A12, and microbial products (e.g. short-chain fatty acids. Dysfunction of any component can lead to the development of intestinal disease, and different diseases have been associated with different faecal levels of these biomarkers. Stool quantification of these biomarkers therefore provides a non- invasive method that can assist in the assessment and diagnosis of various gastrointestinal conditions. This can potentially reduce the need for invasive procedures such as endoscopy. The abovementioned faecal biomarkers and their role in intestinal health and disease will be reviewed in this paper with a paediatric focus.

  20. Guiding the vaginal microbicide trials with biomarkers of inflammation

    OpenAIRE

    Fichorova, Raina N.

    2004-01-01

    This article discusses cytokine patterns as potential biomarkers of vaginal inflammation, which are needed for the safety evaluation of topical microbicide products for the prevention of sexually transmitted HIV-1 infection. In order to be effective, the vaginal anti-HIV-1 microbicides should avoid proinflammatory responses that facilitate transepithelial viral penetration and replication. Pro-inflammatory and anti-inflammatory cytokines play bi-directional roles in HIV-1 pathogenesis, transm...

  1. Biomarkers of Exposure to Triclocarban in Urine and Serum

    OpenAIRE

    Ye, Xiaoyun; Zhou, Xiaoliu; Furr, Johnathan; Ahn, Ki Chang; Bruce D Hammock; Gray, Earl L.; Calafat, Antonia M.

    2011-01-01

    3, 4, 4’- Trichlorocarbanilide (triclocarban, TCC) is widely used as an antimicrobial agent in a variety of consumer and personal care products. TCC is considered a potential endocrine disruptor, but its potential toxic effects in humans are still largely unknown. Because of its widespread uses, the potential for human exposure to TCC is high. In order to identify adequate exposure biomarkers of TCC, we investigated the metabolic profile of TCC in adult female Sprague Dawley rats after admini...

  2. Molecular biomarkers for grass pollen immunotherapy.

    Science.gov (United States)

    Popescu, Florin-Dan

    2014-03-26

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.

  3. Advances in Biomarker Research in Parkinson's Disease.

    Science.gov (United States)

    Mehta, Shyamal H; Adler, Charles H

    2016-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disease, and the numbers are projected to double in the next two decades with the increase in the aging population. An important focus of current research is to develop interventions to slow the progression of the disease. However, prerequisites to it include the development of reliable biomarkers for early diagnosis which would identify at-risk groups and disease progression. In this review, we present updated evidence of already known clinical biomarkers (such as hyposmia and rapid eye movement (REM) sleep behavior disorder (RBD)) and neuroimaging biomarkers, as well as newer possible markers in the blood, CSF, and other tissues. While several promising candidates and methods to assess these biomarkers are on the horizon, it is becoming increasingly clear that no one candidate will clearly fulfill all the roles as a single biomarker. A multimodal and combinatorial approach to develop a battery of biomarkers will likely be necessary in the future. PMID:26711276

  4. Peripheral Blood Biomarkers in Idiopathic Pulmonary Fibrosis

    OpenAIRE

    Vij, Rekha; Noth, Imre

    2012-01-01

    In this article, we review the evidence for peripheral blood biomarkers in idiopathic pulmonary fibrosis (IPF), a life-threatening fibrotic lung disease of unknown etiology. We focus on selected biomarkers present in peripheral blood, as they are easy to obtain, can be measured longitudinally, and have the greatest likelihood of achieving clinical utility. This article concentrates on biomarkers with mechanistic plausibility that may be directly involved in the development of IPF, including K...

  5. Biomarkers of HIV-associated Cancer

    OpenAIRE

    Brian Thabile Flepisi; Patrick Bouic; Gerhard Sissolak; Bernd Rosenkranz

    2014-01-01

    Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of can...

  6. New serum biomarkers for prostate cancer diagnosis

    OpenAIRE

    Chadha, Kailash C.; Austin Miller; Nair, Bindukumar B.; Schwartz, Stanley A.; Trump, Donald L.; Willie Underwood

    2014-01-01

    Background: Prostate-specific antigen (PSA) is currently used as a biomarker for diagnosis and management of prostate cancer (CaP). However, PSA typically lacks the sensitivity and specificity desired of a diagnostic marker. Objective: The goal of this study was to identify an additional biomarker or a panel of biomarkers that is more sensitive and specific than PSA in differentiating benign versus malignant prostate disease and/or localized CaP versus metastatic CaP. Methods: Concurrent meas...

  7. Dietary biomarkers: advances, limitations and future directions

    OpenAIRE

    Hedrick Valisa E; Dietrich Andrea M; Estabrooks Paul A; Savla Jyoti; Serrano Elena; Davy Brenda M

    2012-01-01

    Abstract The subjective nature of self-reported dietary intake assessment methods presents numerous challenges to obtaining accurate dietary intake and nutritional status. This limitation can be overcome by the use of dietary biomarkers, which are able to objectively assess dietary consumption (or exposure) without the bias of self-reported dietary intake errors. The need for dietary biomarkers was addressed by the Institute of Medicine, who recognized the lack of nutritional biomarkers as a ...

  8. Biological Networks for Cancer Candidate Biomarkers Discovery

    Science.gov (United States)

    Yan, Wenying; Xue, Wenjin; Chen, Jiajia; Hu, Guang

    2016-01-01

    Due to its extraordinary heterogeneity and complexity, cancer is often proposed as a model case of a systems biology disease or network disease. There is a critical need of effective biomarkers for cancer diagnosis and/or outcome prediction from system level analyses. Methods based on integrating omics data into networks have the potential to revolutionize the identification of cancer biomarkers. Deciphering the biological networks underlying cancer is undoubtedly important for understanding the molecular mechanisms of the disease and identifying effective biomarkers. In this review, the networks constructed for cancer biomarker discovery based on different omics level data are described and illustrated from recent advances in the field.

  9. Biological Networks for Cancer Candidate Biomarkers Discovery.

    Science.gov (United States)

    Yan, Wenying; Xue, Wenjin; Chen, Jiajia; Hu, Guang

    2016-01-01

    Due to its extraordinary heterogeneity and complexity, cancer is often proposed as a model case of a systems biology disease or network disease. There is a critical need of effective biomarkers for cancer diagnosis and/or outcome prediction from system level analyses. Methods based on integrating omics data into networks have the potential to revolutionize the identification of cancer biomarkers. Deciphering the biological networks underlying cancer is undoubtedly important for understanding the molecular mechanisms of the disease and identifying effective biomarkers. In this review, the networks constructed for cancer biomarker discovery based on different omics level data are described and illustrated from recent advances in the field. PMID:27625573

  10. Biomarkers of peripheral muscle fatigue during exercise

    Directory of Open Access Journals (Sweden)

    Finsterer Josef

    2012-11-01

    Full Text Available Abstract Background Biomarkers of peripheral muscle fatigue (BPMFs are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. Results BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxidative-metabolism. Muscle fatigue is also related to an immunological response. impaired calcium handling, disturbances in bioenergetic pathways, and genetic responses. The immunological and genetic response may make the muscle susceptible to fatigue but may not directly cause muscle fatigue. Production of BPMFs is predominantly dependent on the type of exercise. BPMFs need to change as a function of the process being monitored, be stable without appreciable diurnal variations, correlate well with exercise intensity, and be present in detectable amounts in easily accessible biological fluids. The most well-known BPMFs are serum lactate and interleukin-6. The most widely applied clinical application is screening for defective oxidative metabolism in mitochondrial disorders by means of the lactate stress test. The clinical relevance of most other BPMFs, however, is under debate, since they often depend on age, gender, physical fitness, the energy supply during exercise, the type of exercise needed to produce the BPMF, and whether healthy or diseased subjects are investigated. Conclusions Though the role of BPMFs during fatigue is poorly understood, measuring BPMFs under specific, standardised conditions appears to be helpful for assessing biological states or processes during exercise and fatigue.

  11. Temporal Trends in Syngenetic Lipid Biomarker Signals from Proterozoic Sedimentary Organic Matter

    Science.gov (United States)

    Love, G. D.; Li, C.; Summons, R. E.

    2008-12-01

    The development of continuous-flow catalytic hydropyrolysis (HyPy) for reproducible recovery of biomarker lipid skeletons covalently-bound within kerogen has proved to be an important analytical breakthrough for ancient lipid biomarker research. The parallel analyses of free (solvent-extractable) and kerogen-bound biomarkers affords more confidence that we have correctly identified syngenetic compounds. Combining HyPy with detailed biomarker product analyzes using metastable reaction monitoring-gas chromatography mass spectrometry (MRM-GC-MS) allows detection of a large suite of biomarker compounds which are usually too low in abundance to be analyzed in detail using conventional GC-MS. Here we compare free and bound lipid biomarker records generated from Paleoproterozoic (ca. 1.7 Ga) to Late Ediacaran age (ca. 542 Ma) strata from marine basins from North and South China, Australia and Oman. Fundamental changes in eukaryotic community structure are evident after the Sturtian glaciation (ca. 713 Ma) from distinctive sterane distributions. In particular, radiations in basal animals (sponges) and chlorophyte microalgae are first apparent in Huqf sedimentary rocks from South Oman Salt Basin. Marine microbial communities were not globally homogenous in contemporaneous Proterozoic settings from comparison of biomarker profiles and this could reflect differences in ocean chemistry, affecting nutrient supply, from basin to basin.

  12. Epikardiales Fett als Biomarker? // Epicardial Adipose Tissue as a Biomarker?

    Directory of Open Access Journals (Sweden)

    Tscharre M

    2016-01-01

    Full Text Available Epicardial adipose tissue as the “visceral” adipose tissue of the heart is arousing more and more scientific interest, as it has numerous local and systemic effects. There is no fascia separating the epicardial adipose tissue and the myocardium and they both share its blood supply via the coronary arteries, thus allowing a possible interaction. Under normal physiological conditions, epicardial adipose tissue has mainly anti-atherogenic, thermogenic and mechanical characteristics. Under pathological conditions it becomes harmful to the myocardium and the coronary arteries. Important features in the clinical setting are correlations with coronary artery disease, heart failure, atrial fibrillation and visceral adipose tissue, thus acting as a possible biomarker of cardiovascular risk. p bKurzfassung:/b Das epikardiale Fettgewebe erweckt als „viszerales“ Fettdepot des Herzens mit zahlreichen lokalen und systemischen Effekten immer mehr wissenschaftliches Interesse. Das Fehlen einer trennenden Faszie zwischen epikardialem Fettgewebe und Myokard und die gemeinsame Blutversorgung durch die Koronararterien erlauben eine potenzielle Interaktion. Unter normalen physiologischen Verhältnissen hat das epikardiale Fettgewebe hauptsächlich anti-atherogene, thermogenetische und mechanische Funktionen. Unter pathologischen Verhältnissen schädigt es das Myokard und die Koronararterien. Einen klinischen Stellenwert hat es aufgrund von Korrelationen mit koronarer Herzerkrankung, Herzinsuffizienz, Vorhofflimmern und viszeralem Fettgewebe. Dadurch könnte es als neuer Biomarker für das kardiovaskuläre Risiko dienen.

  13. An extended EPQ-based problem with a discontinuous delivery policy, scrap rate, and random breakdown.

    Science.gov (United States)

    Chiu, Singa Wang; Lin, Hong-Dar; Song, Ming-Syuan; Chen, Hsin-Mei; Chiu, Yuan-Shyi P

    2015-01-01

    In real supply chain environments, the discontinuous multidelivery policy is often used when finished products need to be transported to retailers or customers outside the production units. To address this real-life production-shipment situation, this study extends recent work using an economic production quantity- (EPQ-) based inventory model with a continuous inventory issuing policy, defective items, and machine breakdown by incorporating a multiple delivery policy into the model to replace the continuous policy and investigates the effect on the optimal run time decision for this specific EPQ model. Next, we further expand the scope of the problem to combine the retailer's stock holding cost into our study. This enhanced EPQ-based model can be used to reflect the situation found in contemporary manufacturing firms in which finished products are delivered to the producer's own retail stores and stocked there for sale. A second model is developed and studied. With the help of mathematical modeling and optimization techniques, the optimal run times that minimize the expected total system costs comprising costs incurred in production units, transportation, and retail stores are derived, for both models. Numerical examples are provided to demonstrate the applicability of our research results. PMID:25821853

  14. Accelerated pericyte degeneration and blood-brain barrier breakdown in apolipoprotein E4 carriers with Alzheimer's disease.

    Science.gov (United States)

    Halliday, Matthew R; Rege, Sanket V; Ma, Qingyi; Zhao, Zhen; Miller, Carol A; Winkler, Ethan A; Zlokovic, Berislav V

    2016-01-01

    The blood–brain barrier (BBB) limits the entry of neurotoxic blood-derived products and cells into the brain that is required for normal neuronal functioning and information processing. Pericytes maintain the integrity of the BBB and degenerate in Alzheimer’s disease (AD). The BBB is damaged in AD, particularly in individuals carrying apolipoprotein E4 (APOE4) gene, which is a major genetic risk factor for late-onset AD. The mechanisms underlying the BBB breakdown in AD remain, however, elusive. Here, we show accelerated pericyte degeneration in AD APOE4 carriers >AD APOE3 carriers >non-AD controls, which correlates with the magnitude of BBB breakdown to immunoglobulin G and fibrin. We also show accumulation of the proinflammatory cytokine cyclophilin A (CypA) and matrix metalloproteinase-9 (MMP-9) in pericytes and endothelial cells in AD (APOE4 >APOE3), previously shown to lead to BBB breakdown in transgenic APOE4 mice. The levels of the apoE lipoprotein receptor, low-density lipoprotein receptor-related protein-1 (LRP1), were similarly reduced in AD APOE4 and APOE3 carriers. Our data suggest that APOE4 leads to accelerated pericyte loss and enhanced activation of LRP1-dependent CypA–MMP-9 BBB-degrading pathway in pericytes and endothelial cells, which can mediate a greater BBB damage in AD APOE4 compared with AD APOE3 carriers.

  15. [Biomarkers in inflammatory bowel diseases].

    Science.gov (United States)

    Roblin, Xavier; Cavaille, Alaric; Clavel, Léa; Paul, Stéphane

    2014-01-01

    Fecal calprotectine is of interest for diagnosis of IBD at the beginning. CRP and fecal calprotectine are predictive of long-term response in patients treated by anti-TNF therapy. Trough levels of anti-TNF are associated to clinical remission and mucosal healing. Detectable antibodies to anti-TNF are associated with lower response to treatment. Interventional studies are waiting before optimization of treatment in function of biomarkers. Trough levels of anti-TNF help to modify our treatment (optimization or de-escalation). PMID:24373717

  16. Thermal Reversible Breakdown and Resistivity Switching in Hafnium Dioxide

    Directory of Open Access Journals (Sweden)

    N. Raghavan

    2012-03-01

    Full Text Available We present a model of thermal reversible breakdown via conductive filaments (CFs in hafnium dioxide (HfO2. These CFs appear as a result of electrical pretreatment of a metal/HfO2/metal (semiconductor nanostructure (MIM(S. The model is based on an assumption that the thermal reversible breakdown of a CF is due to of Joule heating displaying an exponential dependence of conductivity on temperature. The corresponding current-voltage characteristic and temperature of a CF in its middle and at the interface with an electrode are calculated taking into account the heat conduction equation and boundary conditions with heat dissipation via electrodes. It is found that the current-voltage characteristic of a CF has three specific regions. The initial and final regions have turned out to be linear with respect to the current and display different slopes, while the middle region is characterized by both the S-shaped and ultralinear dependences which are affected by the ambient temperature and nanostructure parameters. The switching potential from the high resistivity state (HRS to the low resistivity state (LRS was shown to decrease with the ambient temperature and with worsening of heat dissipation conditions. We present a model of thermal reversible breakdown via conductive filaments (CFs in hafnium dioxide (HfO2. These CFs appear as a result of electrical pretreatment of a metal/HfO2/metal (semiconductor nanostructure (MIM(S. The model is based on an assumption that the thermal reversible breakdown of a CF is due to of Joule heating displaying an exponential dependence of conductivity on temperature. The corresponding current-voltage characteristic and temperature of a CF in its middle and at the interface with an electrode are calculated taking into account the heat conduction equation and boundary conditions with heat dissipation via electrodes. It is found that the current-voltage characteristic of a CF has three specific regions. The initial and

  17. PHENIX Work Breakdown Structure. Cost and schedule review copy

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds are shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M&S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M&S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry.

  18. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Science.gov (United States)

    Pořízka, P.; Prochazka, D.; Pilát, Z.; Krajcarová, L.; Kaiser, J.; Malina, R.; Novotný, J.; Zemánek, P.; Ježek, J.; Šerý, M.; Bernatová, S.; Krzyžánek, V.; Dobranská, K.; Novotný, K.; Trtílek, M.; Samek, O.

    2012-08-01

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters.

  19. Use of biomarkers in the context of orphan medicines designation in the European Union.

    Science.gov (United States)

    Tsigkos, Stelios; Llinares, Jordi; Mariz, Segundo; Aarum, Stiina; Fregonese, Laura; Dembowska-Baginska, Bozenna; Elbers, Rembert; Evers, Pauline; Foltanova, Tatiana; Lhoir, Andre; Corrêa-Nunes, Ana; O'Connor, Daniel; Voordouw, Albertha; Westermark, Kerstin; Sepodes, Bruno

    2014-01-01

    The use of biomarkers within the procedures of the Committee of Orphan Medicinal Products (COMP) of the European Medicines Agency (EMA) is discussed herein. The applications for Orphan Medicinal Product designation in the EU are evaluated at two stages. At the time of orphan designation application, the file undergoes an assessment to establish whether the proposed condition is a distinct and serious condition affecting not more than 5 in 10,000 people in the EU, and whether the product is plausible as a therapy for that condition. In cases where therapies already exist, the significant benefit of the candidate product over existing therapies is also evaluated. The orphan criteria are reassessed at the time of marketing authorisation, so that marketing exclusivity for the product in the orphan medical condition can be granted. Within this context, biomarkers have been used in submissions in order to define an orphan condition and to justify that the criteria for orphan designation are met. The current work discusses specific examples from the experience of the COMP, where biomarkers have played a decisive role. Importantly, it identifies the proposal of sub-sets of non-rare conditions based on biomarkers as a challenging issue in the evaluation of applications. In particular two specific requirements for the candidate orphan medicines in relation to the biomarker-based subsets are highlighted: the "plausible link to the condition" and the "exclusion of effects outside the subset". PMID:24461084

  20. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  1. Dielectric breakdown in nano-porous thin films

    Science.gov (United States)

    Borja, Juan Pablo

    Unknown to most computer users and mobile device enthusiasts, we have finally entered into a critical age of chip manufacturing. January of 2014 marks the official start of the quest by the semiconductor industry to successfully integrate sub 14nm process technology nodes in accordance to the International Technology Roadmap for Semiconductors (ITRS). The manufacturing of nano-scale features represents a major bottleneck of its own. However, a bigger challenge lies in reliably isolating the massive chip interconnect network. The present work is aimed at generating a theoretical and experimental framework to predict dielectric breakdown for thin films used in computer chip components. Here, a set of experimental techniques are presented to assess and study dielectric failure in novel thin films. A theory of dielectric breakdown in thin nano-porous films is proposed to describe combined intrinsic and metal ion catalyzed failure. This theory draws on experimental evidence as well as fundamental concepts from mass and electronic charge transport. The drift of metal species was found to accelerate intrinsic dielectric failure. The solubility of metals species such as Cu was found to range from 7.0x1025 ions/m3 to 1.86x1026 ions/m3 in 7% porous SiCOH films. The diffusion coefficient for Cu species was found to span from 4.2x10-19 m2/s to 1.86x10-21 m2/s. Ramped voltage stress experiments were used to identify intrinsic failure from metal catalyzed failure. Intrinsic breakdown is defined when time to failure against applied field ramp rate results in ∂(ln(TTF))/∂(ln(R)) ≈ -1. Intrinsic failure was studied using Au. Here, ∂(ln(TTF))/∂(ln(R)) ≈ -0.95, which is an experimental best case scenario for intrinsic failure. Au is commonly reluctant to ionize which means that failure occurs in the absence of ionic species. Metal catalyzed failure was investigated using reactive electrodes such as Cu, and Ag. Here, trends for ∂(ln(TTF))/∂(ln(R)) significantly

  2. Kinetic modeling of the Townsend breakdown in argon

    Science.gov (United States)

    Macheret, S. O.; Shneider, M. N.

    2013-10-01

    Kinetic modeling of the Townsend breakdown in argon was performed in the "forward-back" approximation. The kinetic model was found to adequately describe the left branch of the Paschen curve, and the important role of ionization by fast ions and atoms near the cathode, as well as the increase in secondary emission coefficient in strong electric fields described in the literature, was confirmed. The modeling also showed that the electron energy distribution function develops a beam of high-energy electrons and that the runaway effect, i.e., the monotonic increase of the mean electron energy with the distance from the cathode, occurs at the left branch of the Paschen curve.

  3. Controlled calibration method for laser induced breakdown spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Chijian Zhang; Yuan Feng

    2008-01-01

    Laser induced breakdown spectroscopy (LIBS) is a potential technique for rapid analysis of samples present in solids, gases and liquids. In the last two decades it was an object of extensive studies. Controlled calibration method used to analysis the LIBS spectra is investigated. Compared with the inner calibration and calibration-free (CF) methods, this new method overcomes "matrix effect", and demonstrates a better ability to cope with the spectra. It is used to analyze natural soil, and errors of the concentration are decreased about 5%. The result shows that the new method is feasible and accurate.

  4. Breakdown of the Dipole Approximation in Strong-Field Ionization

    OpenAIRE

    Ludwig, A.; J. Maurer; MAYER, B.W.; Phillips, C. R.; Gallmann, L; Keller, U.

    2014-01-01

    We report the breakdown of the electric dipole approximation in the long-wavelength limit in strong-field ionization with linearly polarized few-cycle mid-infrared laser pulses at intensities on the order of 10$^{13}$ W/cm$^2$. Photoelectron momentum distributions were recorded by velocity map imaging and projected onto the beam propagation axis. We observe an increasing shift of the peak of this projection opposite to the beam propagation direction with increasing laser intensities. From a c...

  5. Biomedical and environmental applications of laser-induced breakdown spectroscopy

    Indian Academy of Sciences (India)

    V K Unnikrishnan; K S Choudhari; Suresh D Kulkarni; Rajesh Nayak; V B Kartha; C Santhosh; B M Suri

    2014-02-01

    Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, minimal sample preparation, minimal destruction, low cost and versatility of being applied to a wide range of materials. In this paper, we report the preliminary observations we obtained using LIBS for clinical and environmental samples. Elemental analysis has been done qualitatively in human teeth samples which show encouraging results. It has also been demonstrated in this paper that LIBS can be very well utilized in field applications such as plastic waste sorting and recycling.

  6. Electrical Breakdown Characteristic of Nanostructured W-Cu Contacts Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Junbo; CHEN Wen'ge; DING Bingjun

    2006-01-01

    Nanostructured (NS) W- Cu composite powder was prepared by mechanical alloying ( MA ), and nanostructured bulk of W- Cu contact material was fabricated by hot press sintering in an electrical vacuum furnace. The microstructure, electric conductivity, hardness and break down voltage of NS W-Cu alloys were measured and compared to those of conventional W- Cu alloys prepared by powder metallurgy. The experimental results show that microstructural refinement and uniformity can improve the breakdown behavior and the electric arc stability of nanostructured W- Cu contacts materials. Also, the nanostructured W- Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

  7. Individual breakdown of pension rights and end of contract

    CERN Multimedia

    2015-01-01

    As in previous years, members of the CERN Pension Fund will shortly receive their “Individual breakdown of pension rights” by e-mail.   In this respect, we would like to remind members that according to Articles II 1.11 - II 1.12 (calculation and payment of the transfer value) and II 2.02 (retirement pension), several options are possible at the end of their contract (depending on their length of service in the Fund): payment of the transfer value into a personal bank account, payment of the transfer value into a new pension scheme, pension (deferred, anticipated or retirement). Benefits Service CERN Pension Fund

  8. Breakdown of the dipole approximation in strong-field ionization.

    Science.gov (United States)

    Ludwig, A; Maurer, J; Mayer, B W; Phillips, C R; Gallmann, L; Keller, U

    2014-12-12

    We report the breakdown of the electric dipole approximation in the long-wavelength limit in strong-field ionization with linearly polarized few-cycle mid-infrared laser pulses at intensities on the order of 10¹³ W/cm². Photoelectron momentum distributions were recorded by velocity map imaging and projected onto the beam propagation axis. We observe an increasing shift of the peak of this projection opposite to the beam propagation direction with increasing laser intensities. From a comparison with semiclassical simulations, we identify the combined action of the magnetic field of the laser pulse and the Coulomb potential as the origin of our observations. PMID:25541770

  9. Breakdown of 1D water wires inside Charged Carbon Nanotubes

    CERN Document Server

    Pant, Shashank

    2016-01-01

    Using Molecular Dynamics approach we investigated the structure, dynamics of water confined inside pristine and charged 6,6 carbon nanotubes (CNTs). This study reports the breakdown of 1D water wires and the emergence of triangular faced water on incorporating charges in 6,6 CNTs. Incorporation of charges results in high potential barriers to the flipping of water molecules due to the formation of a large number of hydrogen bonds. The PMF analyses show the presence of ~2 kcal/mol barrier for the movement of water inside pristine CNT and almost negligible barrier in charged CNTs.

  10. Continuous breakdown of Purcell's scallop theorem with inertia

    CERN Document Server

    Lauga, Eric

    2007-01-01

    Purcell's scallop theorem defines the type of motions of a solid body - reciprocal motions - which cannot propel the body in a viscous fluid with zero Reynolds number. For example, the flapping of a wing is reciprocal and, as was recently shown, can lead to directed motion only if its frequency Reynolds number, Re_f, is above a critical value of order one. Using elementary examples, we show the existence of oscillatory reciprocal motions which are effective for all arbitrarily small values of the frequency Reynolds number and induce net velocities scaling as (Re_f)^\\alpha (alpha > 0). This demonstrates a continuous breakdown of the scallop theorem with inertia.

  11. Experimental study of vortex breakdown in swirling jets

    Science.gov (United States)

    Billant, Paul; Chomaz, Jean-Marc; Huerre, Patrick

    1998-12-01

    The goal of this study is to characterize the various breakdown states taking place in a swirling water jet as the swirl ratio S and Reynolds number Re are varied. A pressure-driven water jet discharges into a large tank, swirl being imparted by means of a motor which sets into rotation a honeycomb within a settling chamber. The experiments are conducted for two distinct jet diameters by varying the swirl ratio S while maintaining the Reynolds number Re fixed in the range 300secondary recirculating motions that are independent of confinement effects.

  12. Laser-Induced Breakdown Spectroscopy (LIBS): specific applications

    Science.gov (United States)

    Trtica, M. S.; Savovic, J.; Stoiljkovic, M.; Kuzmanovic, M.; Momcilovic, M.; Ciganovic, J.; Zivkovic, S.

    2015-12-01

    A short overview of Laser Induced Breakdown Spectroscopy (LIBS) with emphasis on the new trends is presented. Nowadays, due to unique features of this technique, LIBS has found applications in a great variety of fields. Achievements in the application of LIBS in nuclear area, for hazardous materials detection and in geology were considered. Also, some results recently obtained at VINCA Institute, with LIBS system based on transversely excited atmospheric (TEA) CO2 laser, are presented. Future investigations of LIBS will be oriented toward further improvement of the analytical performance of this technique, as well as on finding new application fields.

  13. Biomarkers of chronic alcohol misuse

    Directory of Open Access Journals (Sweden)

    Gonzalo P

    2014-01-01

    Full Text Available Philippe Gonzalo,1 Sylvie Radenne,2 Sylvie Gonzalo31Laboratoire de Biochimie, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Etienne, France; 2Service d'Hépatologie-Gastroentérologie, Hôpital de la Croix Rousse, Hospices Civils de Lyon, Lyon, France; 3Laboratoire Biomnis, Lyon, FranceAbstract: Biological markers of chronic alcoholism can be divided into two groups: direct and indirect markers. Direct markers (mainly blood or serum and urine ethanol, ethylglucuronide, ethyl sulfate, and phosphatidylethanol directly track the intake of alcohol and vary in their sensitivity and kinetics of appearance and clearance. Indirect markers (mean corpuscular volume,γ-glutamyl transferase, alanine aminotransferase and aspartate aminotransferase, and carbohydrate-deficient transferrin are biological parameters that are influenced by a steady and significant alcohol intake. We discuss the values of these tests and the relevance of their prescriptions for the clinical evaluation of heavy drinking. We indicate, when known, the pathophysiological mechanism of their elevations. We also discuss the amount and time of alcohol consumption required to give a positive result and the duration of abstinence required for the return to normal values. The forensic use of these biomarkers will not be considered in this review.Keywords: alcoholism, biomarker, CDT, relapse, alcohol-induced liver disease

  14. Biomarkers in Pancreatic Neuroendocrine Tumors

    Directory of Open Access Journals (Sweden)

    Maria Serafeim Theochari

    2014-03-01

    Full Text Available The aim of biomarkers is to identify patients most likely to benefit from a therapeutic strategy. Pancreatic neuroendocrinetumors are rare neoplasms that arise in the endocrine tissues of the pancreas. Pancreatic neuroendocrine tumors represent3% of primary pancreatic neoplasms and their incidence has risen. The SMAD4 gene is located on chromosome 18q andsomeday the SMAD4 gene status may be useful for prognostic stratification and therapeutic decision. The cells respond toenvironmental signals by modulating the expressions of genes contained within the nucleus, when genes are activated aretranscribed to generate messenger RNA (mRNA. The examination of multiple expressed genes and proteins provides moreuseful information for prognostication of individual tumors. Here we summarize and discuss findings presented at the 2014ASCO Gastrointestinal Cancers Symposium. Anna Karpathakis et al. (Abstract #212 reported data about the role of DNAmethylation in gastrointestinal neuroendocrine tumors. Christina Lynn Roland et al. (Abstract #250 looked the impact OfSMAD4 on oncologic outcomes. Bong Kynn Kang et al. (Abstract #251 investigated prognostic biomarker using microRNAarray technology.

  15. Biomarkers of aggression in dementia.

    Science.gov (United States)

    Gotovac, Kristina; Nikolac Perković, Matea; Pivac, Nela; Borovečki, Fran

    2016-08-01

    Dementia is a clinical syndrome defined by progressive global impairment of acquired cognitive abilities. It can be caused by a number of underlying conditions. The most common types of dementia are Alzheimer's disease (AD), frontotemporal dementia (FTD), vascular cognitive impairment (VCI) and dementia with Lewy bodies (DLB). Despite the fact that cognitive impairment is central to the dementia, noncognitive symptoms, most commonly described nowadays as neuropsychiatric symptoms (NPS) exist almost always at certain point of the illness. Aggression as one of the NPS represents danger both for patients and caregivers and the rate of aggression correlates with the loss of independence, cognitive decline and poor outcome. Therefore, biomarkers of aggression in dementia patients would be of a great importance. Studies have shown that different genetic factors, including monoamine signaling and processing, can be associated with various NPS including aggression. There have been significant and multiple neurotransmitter changes identified in the brains of patients with dementia and some of these changes have been involved in the etiology of NPS. Aggression specific changes have also been observed in neuropathological studies. The current consensus is that the best approach for development of such biomarkers may be incorporation of genetics (polymorphisms), neurobiology (neurotransmitters and neuropathology) and neuroimaging techniques. PMID:26952705

  16. The Nature of Emission from Optical Breakdown Induced by Pulses of fs and ns Duration

    Energy Technology Data Exchange (ETDEWEB)

    Carr, C W; Feit, M D; Rubenchik, A M; Demange, P; Kucheyev, S; Shirk, M D; Radousky, H B; Demos, S G

    2004-11-09

    Spectral emission from optical breakdown in the bulk of a transparent dielectric contains information about the nature of the breakdown medium. We have made time resolved measurements of the breakdown induced emission caused by nanosecond and femtosecond infrared laser pulses. We previously demonstrated that the emission due to ns pulses is blackbody in nature allowing determination of the fireball temperature and pressure during and after the damage event. The emission due to femtosecond pulse breakdown is not blackbody in nature; two different spectral distributions being noted. In one case, the peak spectral distribution occurs at the second harmonic of the incident radiation, in the other the distribution is broader and flatter and presumably due to continuum generation. The differences between ns and fs breakdown emission can be explained by the differing breakdown region geometries for the two pulse durations. The possibility to use spectral emission as a diagnostic of the emission region morphology will be discussed.

  17. Experimental study of DC vacuum breakdown and application to high-gradient accelerating structures for CLIC

    CERN Document Server

    Shipman, Nicholas; Jones, Roger

    2016-01-01

    The compact linear collider (CLIC) is a leading candidate for the next generation high energy linear collider. As any breakdown would result in a partial or full loss of luminosity for the pulse in which it occurs, obtaining a low breakdown rate in CLIC accelerating structures is a critical requirement for the successful operation of the proposed collider. This thesis presents investigations into the breakdown phenomenon primarily in the low breakdown rate regime of interest to CLIC, performed using the CERN DC spark systems between 2011 and 2014. The design, construction and commissioning of several new pieces of hardware, as well as the development of improved techniques to measuring the inter-electrode gap distance are detailed. These hardware improvements were fundamental in enabling the exciting new experiments mentioned below, which in turn have provided significant additional insight into the phenomenon of breakdown. Experiments were performed to measure fundamental parameters of individual breakdowns...

  18. DC high voltage to drive helium plasma jet comprised of repetitive streamer breakdowns

    CERN Document Server

    Wang, Xingxing

    2016-01-01

    This paper demonstrates and studies helium atmospheric pressure plasma jet comprised of series of repetitive streamer breakdowns, which is driven by a pure DC high voltage (auto-oscillations). Repetition frequency of the breakdowns is governed by the geometry of discharge electrodes/surroundings and gas flow rate. Each next streamer is initiated when the electric field on the anode tip recovers after the previous breakdown and reaches the breakdown threshold value of about 2.5 kV/cm. Repetition frequency of the streamer breakdowns excited using this principle can be simply tuned by reconfiguring the discharge electrode geometry. This custom-designed type of the helium plasma jet, which operates on the DC high voltage and is comprised of the series of the repetitive streamer breakdowns at frequency about 13 kHz, is demonstrated.

  19. Exploration of new HCC biomarkers

    Directory of Open Access Journals (Sweden)

    Regina M. Santella

    2007-02-01

    Full Text Available

    Analysis of plasma/serum for levels of viral antigens or antibodies to viral proteins has been used extensively as an early biomarker of potential risk of HCC. In addition, detection of elevated levels of alpha-fetoprotein is commonly used for early identification of HCC. Unfortunately, both of these approaches are not highly sensitive or specific. As a result, there is continuing investigation to identify additional biomarkers that may help in the early identification of cases. The use of DNA isolated from plasma or serum for detection of gene specific methylation has been discussed previously. In addition, tumor DNA isolated from blood has been analyzed for the presence of p53 mutations and found in a subset of cases to be present years prior to diagnosis as for methylated DNA. The general level of DNA present in blood has also been suggested as a potential biomarker of cancer.

    Among the newer methods being tested are the detection of specific mutations in HBV. In many cases of HCC in China and Africa a double mutation, an A to T transversion at nucleotide 1762 and a G to A transition at nucleotide 1764 (1762T/1764A have been found. These mutations have been associated with increased severity of HBV infection and cirrhosis suggesting that they might be a useful biomarker for high risk subjects.

    The field of proteomics also holds promise for the development of new biomarkers. A number of groups are developing mass spectrometry methods for the identification of serum/plasma proteomic patterns that will distinguish bloods of HCC cases from those of controls. While some interesting preliminary data have been developed for several cancers, much additional work needs to be done in this area

  20. Bias in emerging biomarkers for bipolar disorder

    DEFF Research Database (Denmark)

    Carvalho, A F; Köhler, C A; Fernandes, B S;

    2016-01-01

    BACKGROUND: To date no comprehensive evaluation has appraised the likelihood of bias or the strength of the evidence of peripheral biomarkers for bipolar disorder (BD). Here we performed an umbrella review of meta-analyses of peripheral non-genetic biomarkers for BD. METHOD: The Pubmed...

  1. Current and emerging biomarkers of hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Yang X

    2012-08-01

    Full Text Available Xi Yang, William F Salminen, Laura K SchnackenbergDivision of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USAAbstract: Drug-induced liver injury (DILI is of great concern to human health. Generally, liver function and injury is evaluated based upon clinical signs, a select group of serum clinical biomarkers, and occasionally liver biopsies. While alanine aminotransferase, the most commonly used biomarker of hepatocellular injury, is a sensitive marker of liver injury, it is not necessarily specific for liver injury. Furthermore, alanine aminotransferase levels may not always correlate with the extent of injury. Therefore, new hepatotoxicity biomarkers are needed that are more predictive and specific indicators of liver injury and altered function. In addition, no current biomarker provides prognostic information about ultimate outcome once injury occurs, and any new biomarker filling this need is desperately needed. The omics technologies, including genomics, proteomics, and metabolomics, are being used in preclinical animal studies as well as clinical studies to evaluate markers of hepatotoxicity in easily obtained biofluids, such as urine and serum. Recently, the evaluation of circulating microRNAs in urine and blood has also shown promise for the identification of novel, sensitive markers of liver injury. This review evaluates the current status of proposed biomarkers of hepatotoxicity from the omics platforms, as well as from analysis of microRNAs. A brief description of the qualification of proposed biomarkers is also given.Keywords: biomarkers, hepatotoxicity, metabolomics, microRNA, proteomics, transcriptomics

  2. DNA Methylation Biomarkers: Cancer and Beyond

    Directory of Open Access Journals (Sweden)

    Thomas Mikeska

    2014-09-01

    Full Text Available Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient’s response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.

  3. Fluid biomarkers in multiple system atrophy

    DEFF Research Database (Denmark)

    Laurens, Brice; Constantinescu, Radu; Freeman, Roy;

    2015-01-01

    Despite growing research efforts, no reliable biomarker currently exists for the diagnosis and prognosis of multiple system atrophy (MSA). Such biomarkers are urgently needed to improve diagnostic accuracy, prognostic guidance and also to serve as efficacy measures or surrogates of target...

  4. Proteomic Biomarkers for Spontaneous Preterm Birth

    DEFF Research Database (Denmark)

    Kacerovsky, Marian; Lenco, Juraj; Musilova, Ivana;

    2014-01-01

    This review aimed to identify, synthesize, and analyze the findings of studies on proteomic biomarkers for spontaneous preterm birth (PTB). Three electronic databases (Medline, Embase, and Scopus) were searched for studies in any language reporting the use of proteomic biomarkers for PTB published...

  5. Biomarkers in Alzheimer’s disease

    Institute of Scientific and Technical Information of China (English)

    Rajka M Liscic; Yuanhan Yang

    2016-01-01

    Alzheimer’s disease (AD) so far did not have promising treatment. The accurate and early diagnosis is still the important issue. For these purpose, biomarkers related to diagnosis, clinical course, and other aims have been proposed and reported. Meanwhile, along with the ongoing researches for AD, biomarkers with their own aims are also on the way.

  6. Cytokines as Biomarkers in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Agata Burska

    2014-01-01

    Full Text Available RA is a complex disease that develops as a series of events often referred to as disease continuum. RA would benefit from novel biomarker development for diagnosis where new biomarkers are still needed (even if progresses have been made with the inclusion of ACPA into the ACR/EULAR 2010 diagnostic criteria and for prognostic notably in at risk of evolution patients with autoantibody-positive arthralgia. Risk biomarkers for rapid evolution or cardiovascular complications are also highly desirable. Monitoring biomarkers would be useful in predicting relapse. Finally, predictive biomarkers for therapy outcome would allow tailoring therapy to the individual. Increasing numbers of cytokines have been involved in RA pathology. Many have the potential as biomarkers in RA especially as their clinical utility is already established in other diseases and could be easily transferable to rheumatology. We will review the current knowledge’s relation to cytokine used as biomarker in RA. However, given the complexity and heterogeneous nature of RA, it is unlikely that a single cytokine may provide sufficient discrimination; therefore multiple biomarker signatures may represent more realistic approach for the future of personalised medicine in RA.

  7. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope ra

  8. Breakdown in the Organ Donation Process and Its Effect on Organ Availability

    OpenAIRE

    Manik Razdan; Degenholtz, Howard B.; Kahn, Jeremy M; Julia Driessen

    2015-01-01

    Background. This study examines the effect of breakdown in the organ donation process on the availability of transplantable organs. A process breakdown is defined as a deviation from the organ donation protocol that may jeopardize organ recovery. Methods. A retrospective analysis of donation-eligible decedents was conducted using data from an independent organ procurement organization. Adjusted effect of process breakdown on organs transplanted from an eligible decedent was examined using mul...

  9. A possible new mechanism involved in non-uniform field breakdown in gaseous dielectrics

    International Nuclear Information System (INIS)

    The electrical breakdown of gases under uniform field conditions is fairly well understood in terms of the Townsend's breakdown theory. In most cases involving uniform fields, the breakdown voltage can be estimated via this theory using basic electron impact parameters for molecules in their ground electronic states. In contrast, a consistent model of gaseous breakdown under nonuniform fields is not available at present although substantial progress has been made recently. We point out the possibility that electron impact processes involving high-lying electronically-excited states may play a significant role under non-uniform field conditions. Thus, such processes may need to be included in order to obtain a better understanding of non-uniform field breakdown phenomena. The general, breakdown characteristics of highly non-uniform field gaps can be illustrated by that for a point-plane geometry. It has been found that the breakdown voltage for such a gap can be calculated by a simple streamer criterion if the pressure P, is above a critical value, Pc; for P c, the estimated breakdown voltage is found to coincide with the corona inception voltage, with the actual breakdown occurring at a higher voltage, corona discharges occur only for P c. In other words, the presence of corona in the pressure region below Pc seems to prevent the breakdown from occurring at the predicted value. This has led to the term ''corona stabilization'' to describe the enhancement in the breakdown voltage for pressures below Pc. Non-uniform field breakdown measurements in gases will be discussed. We will discuss the possibility that the ''corona stabilization'' is due to the prevention of avalanche progression by attachment of free electrons to molecules in their high-lying electronically-excited states. Information on electron attachment to electronically-excited states of molecules was not available up until the late 1980's

  10. A possible new mechanism involved in non-uniform field breakdown in gaseous dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Pinnaduwage, L.A.; Christophorou, L.G.

    1994-06-01

    The electrical breakdown of gases under uniform field conditions is fairly well understood in terms of the Townsend`s breakdown theory. In most cases involving uniform fields, the breakdown voltage can be estimated via this theory using basic electron impact parameters for molecules in their ground electronic states. In contrast, a consistent model of gaseous breakdown under nonuniform fields is not available at present although substantial progress has been made recently. We point out the possibility that electron impact processes involving high-lying electronically-excited states may play a significant role under non-uniform field conditions. Thus, such processes may need to be included in order to obtain a better understanding of non-uniform field breakdown phenomena. The general, breakdown characteristics of highly non-uniform field gaps can be illustrated by that for a point-plane geometry. It has been found that the breakdown voltage for such a gap can be calculated by a simple streamer criterion if the pressure P, is above a critical value, P{sub c}; for P < P{sub c}, the estimated breakdown voltage is found to coincide with the corona inception voltage, with the actual breakdown occurring at a higher voltage, corona discharges occur only for P < P{sub c}. In other words, the presence of corona in the pressure region below P{sub c} seems to prevent the breakdown from occurring at the predicted value. This has led to the term ``corona stabilization`` to describe the enhancement in the breakdown voltage for pressures below P{sub c}. Non-uniform field breakdown measurements in gases will be discussed. We will discuss the possibility that the ``corona stabilization`` is due to the prevention of avalanche progression by attachment of free electrons to molecules in their high-lying electronically-excited states. Information on electron attachment to electronically-excited states of molecules was not available up until the late 1980`s.

  11. Melanoma biomarkers: Vox clamantis in deserto (Review).

    Science.gov (United States)

    Al-Shaer, Mays; Gollapudi, Divya; Papageorgio, Chris

    2010-05-01

    Detecting malignant melanoma at an early stage, monitoring therapy, predicting recurrence and identifying patients at risk for metastasis continue to be a challenging and demanding objective. The last two decades have witnessed innovations in the field of melanoma biomarkers. However, global agreement concerning monitoring and early detection has yet to be reached. This is a review of the current literature regarding melanoma biomarkers including demographic, clinical, pathological and molecular biomarkers that are produced by melanoma or non-melanoma cells. A number of these biomarkers demonstrate promising results as possible methods for early detection, predicting recurrence and monitoring therapy. Other biomarkers appear to be promising for identifying patients at risk for metastasis. We reviewed the most pertinent information in the field thus far and how this knowledge can impact, or not, the management of melanoma patients prognostically and therapeutically. PMID:22966315

  12. Diagnostic and prognostic epigenetic biomarkers in cancer.

    Science.gov (United States)

    Costa-Pinheiro, Pedro; Montezuma, Diana; Henrique, Rui; Jerónimo, Carmen

    2015-01-01

    Growing cancer incidence and mortality worldwide demands development of accurate biomarkers to perfect detection, diagnosis, prognostication and monitoring. Urologic (prostate, bladder, kidney), lung, breast and colorectal cancers are the most common and despite major advances in their characterization, this has seldom translated into biomarkers amenable for clinical practice. Epigenetic alterations are innovative cancer biomarkers owing to stability, frequency, reversibility and accessibility in body fluids, entailing great potential of assay development to assist in patient management. Several studies identified putative epigenetic cancer biomarkers, some of which have been commercialized. However, large multicenter validation studies are required to foster translation to the clinics. Herein we review the most promising epigenetic detection, diagnostic, prognostic and predictive biomarkers for the most common cancers.

  13. Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry

    Science.gov (United States)

    Gucker, Sarah M. N.

    is created either through flowing gas around the high voltage electrode in the discharge tube or self-generated by the plasma as in the steam discharge. This second method allows for large scale processing of contaminated water and for bulk chemical and optical analysis. Breakdown mechanisms of attached and unattached gas bubbles in liquid water were investigated using the first device. The breakdown scaling relation between breakdown voltage, pressure and dimensions of the discharge was studied. A Paschen-like voltage dependence for air bubbles in liquid water was discovered. The results of high-speed photography suggest the physical charging of the bubble due to a high voltage pulse; this charging can be significant enough to produce rapid kinetic motion of the bubble about the electrode region as the applied electric field changes over a voltage pulse. Physical deformation of the bubble is observed. This charging can also prevent breakdown from occurring, necessitating higher applied voltages to overcome the phenomenon. This dissertation also examines the resulting chemistry from plasma interacting with the bubble-liquid system. Through the use of optical emission spectroscopy, plasma parameters such as electron density, gas temperature, and molecular species production and intensity are found to have a time-dependence over the ac voltage cycle. This dependence is also source gas type dependent. These dependencies afford effective control over plasma-driven decomposition. The effect of plasma-produced radicals on various wastewater simulants is studied. Various organic dyes, halogenated compounds, and algae water are decomposed and assessed. Toxicology studies with melanoma cells exposed to plasma-treated dye solutions are completed, demonstrating the non-cytotoxic quality of the decomposition process. Thirdly, this dissertation examines the steam plasma system, developed through this research to circumvent the acidification associated with gas-feed discharges

  14. The research of breakdown structure and coding system for construction project

    Institute of Scientific and Technical Information of China (English)

    丁大勇; 金维兴; 李培

    2004-01-01

    Whether the breakdown structure and coding system of construction projects are reasonable or not determines to a large degree the pepfofmance level of the entire project management. We analyze in detail the similarities and differences of two kinds of decomposing methods classified by type of work and construction elements based on the discussion of international typical coding standards system designing. We then deduce the differential coefficient relation between project breakdown strueture(PBS) and work breakdown structure (WBS). At the same time we constitute a comprehensive construction project breakdown system including element code and type of work code and make a further schematic presentation of the implementation of the sysrem' s functions.

  15. Fully kinetic model of breakdown during sheath expansion after interruption of vacuum arcs

    Science.gov (United States)

    Wang, Zhenxing; Wang, Haoran; Zhou, Zhipeng; Tian, Yunbo; Geng, Yingsan; Wang, Jianhua; Liu, Zhiyuan

    2016-08-01

    Research on sheath expansion is critical to the understanding of the dielectric recovery process in a vacuum interrupter after interruption of vacuum arcs. In this paper, we investigated how residual plasma affects breakdown in the sheath expansion period after the current zero. To simulate sheath expansion and breakdown, we developed a fully kinetic particle-in-cell Monte Carlo collision model with one spatial dimension and three velocity dimensions. The model accounted for various collisions, including ionization, excitation, elastic collisions, charge exchange, and momentum exchange, and we added an external circuit to the model to make the calculations self-consistent. The existence of metal vapor slowed the sheath expansion in the gap and caused high electric field formation in front of the cathode surface. The initial residual plasma, which was at sufficiently low density, seemed to have a limited impact on breakdown, and the metal vapor dominated the breakdown in this case. Additionally, the breakdown probability was sensitive to the initial plasma density if the value exceeded a specific threshold, and plasma at sufficiently high density could mean that breakdown would occur more easily. We found that if the simulation does not take the residual plasma into account, it could overestimate the critical value of the metal vapor density, which is always used to describe the boundary of breakdown after interruption of vacuum arcs. We discussed the breakdown mechanism in sheath expansion, and the breakdown is determined by a combination of metal vapor, residual plasma, and the electric field in front of the cathode surface.

  16. Oxide thinning percolation statistical model for soft breakdown in ultrathin gate oxides

    Science.gov (United States)

    Chen, Ming-Jer; Kang, Ting-Kuo; Liu, Chuan-Hsi; Chang, Yih J.; Fu, Kuan-Yu

    2000-07-01

    An existing cell-based percolation model with parameter correlation can find its potential applications in assessing soft-breakdown (BD) statistics as long as the oxide thinning due to the localized physical damage near the SiO2/Si interface is accounted for. The resulting model is expressed explicitly with the critical trap number per cell nBD and the remaining oxide thickness tox' both as parameters. Reproduction of time-to-bimodal (soft- and hard-) breakdown statistical data from 3.3-nm-thick gate-oxide samples yields nBD of 3 and 4 for soft and hard breakdown, respectively. The extracted tox' of 1.0 nm for soft breakdown, plus the transition layer thickness of 0.5 nm in the model, is fairly comparable with literature values from current-voltage fitting. The dimension and area of the localized physically damaged region or percolation path (cell) are quantified as well. Based on the work, the origins of soft and hard breakdown are clarified in the following: (i) soft breakdown behaves intrinsically as hard breakdown, that is, they share the same defect (neutral trap) generation process and follow Poisson random statistics; (ii) both are independent events corresponding to different tox' requirements; and (iii) hard breakdown takes place in a certain path located differently from that for the first soft breakdown.

  17. A theoretical estimation of the pre-breakdown-heating time in the underwater discharge acoustic source

    Institute of Scientific and Technical Information of China (English)

    Wang Yi-Bo; Wang Shang-Wu; Zeng Xin-Wu

    2012-01-01

    One of the common characteristics of the electrothermal breakdown in an underwater discharge acoustic source(UDAS)is the existence of a pre-breakdown-heating phase.In our experiment,two phenomena were observed:(1)the breakdown time that takes on high randomicity and obeys a "double-peak" stochastic distribution;(2)the higher salt concentration that reduces the residual voltage and causes 100% non-breakdown.The mechanism of electrothermal breakdown is analysed.To specify the end of the pre-breakdown-heating phase,a "border boiling" assumption is proposed,in which the breakdown time is assumed to be the time needed to heat the border water around the initial arc to 773 K.Based on this ‘border boiling' assumption,the numerical simulation is performed to evaluate the effects of two heating mechanisms:the Joule heating from the ionic current,and the radiation heating from the initial arc.The simulation results verify the theoretical explanations to these two experiment phenomena:(1)the stochastic distribution of the radius of the initial arc results in the randomicity of the breakdown time;(2)the difference in efficiency between the radiation heating and the Joule heating determines that,in the case of higher salt concentration,more energy will be consumed in the pre-breakdown-heating phase.

  18. Preliminary Breakdown: Physical Mechanisms and Potential for Energetic Emissions

    Science.gov (United States)

    Petersen, D.; Beasley, W. H.

    2014-12-01

    Observations and analysis of the preliminary breakdown phase of virgin negative cloud-to-ground (-CG) lightning strokes will be presented. Of primary interest are the physical processes responsible for the fast electric field "characteristic" pulses that are often observed during this phase. The pulse widths of characteristic pulses are shown to occur as a superposed bimodal distribution, with the short and long modes having characteristic timescales on the order of 1 microsecond and 10 microseconds, respectively. Analysis of these pulses is based on comparison with laboratory observations of long spark discharge processes and with recently acquired high-speed video observations of a single -CG event. It will be argued that the fast electric field bimodal distribution is the result of conventional discharge processes operating in an extensive strong ambient electric field environment. An important related topic will also be discussed, where it will be argued that preliminary breakdown discharges are capable of generating energetic electrons and may therefore seed relativistic electron avalanches that go on to produce pulsed energetic photon emissions.

  19. Dielectric breakdown during Cs+ sputtering of polyvinyl chloride

    Science.gov (United States)

    Wahoud, F.; Guillot, J.; Audinot, J. N.; Bertrand, P.; Delcorte, A.; Migeon, H. N.

    2014-02-01

    Thin films of insulating polymers are sometimes analyzed by secondary ion mass spectrometry (SIMS) or by X-ray photoelectron spectroscopy (XPS) without the use of an electron gun. In this work, both SIMS and XPS have been used to study the chemical and structural modifications due to the charge effect during Cs+ sputtering of a thin film of polyvinyl chloride (PVC). The kinetic energy distribution study shows that at a small primary fluence ˜1015 Cs+ ions/cm2, the dielectric breakdown voltage of the PVC film is reached, i.e. the minimum voltage that causes a portion of an insulator to become electrically conductive. XPS study indicates that the conducting phase created in the PVC film after energetic Cs+ bombardment consists of graphitized carbon and metallic cesium clusters. After the dielectric breakdown of the film, the positive charge, previously accumulated on the surface, is neutralized through the conductive regions, which are created in the insulating film. During Cs+ sputtering of a PVC film, the chemical structure of the analyzed surface is completely modified and some ionic bonds such as CsC and CsCl are also created.

  20. Rf breakdown studies in room temperature electron linac structures

    International Nuclear Information System (INIS)

    This paper is an overall review of studies carried out by the authors and some of their colleagues on RF breakdown, Field Emission and RF processing in room temperature electron linac structure. The motivation behind this work is twofold: in a fundamental way, to contribute to the understanding of the RF breakdown phenomenon, and as an application, to determine the maximum electric field gradient that can be obtained and used safely in future e/sup +-/ linear colliders. Indeed, the next generation of these machines will have to reach into the TeV (1012 eV) energy range, and the accelerating gradient will be to be of the crucial parameters affecting their design, construction and cost. For a specified total energy, the gradient sets the accelerator length, and once the RF structure, frequency and pulse repetition rate are selected, it also determines the peak and average power consumption. These three quantities are at the heart of the ultimate realizability and cost of these accelerators. 24 refs., 19 figs., 4 tabs

  1. A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments

    Science.gov (United States)

    Bourke, Mary C. (Editor); Brearley, J. Alexander; Haas, Randall; Viles, Heather A.

    2007-01-01

    A primary goal of geomorphological enquiry is to make genetic associations between process and form. In rock breakdown studies, the links between process, inheritance and lithology are not well constrained. In particular, there is a need to establish an understanding of feature persistence. That is, to determine the extent to which in situ rock breakdown (e.g., aeolian abrasion or salt weathering) masks signatures of earlier geomorphic transport processes (e.g., fluvial transport or crater ejecta). Equally important is the extent to which breakdown during geomorphic transport masks the imprint of past weathering. The use of rock features in this way raises the important question: Can features on the surface of a rock reliably indicate its geomorphic history? This has not been determined for rock surfaces on Earth or other planets. A first step towards constraining the links between process, inheritance, and morphology is to identify pristine features produced by different process regimes. The purpose of this atlas is to provide a comprehensive image collection of breakdown features commonly observed on boulders in different geomorphic environments. The atlas is intended as a tool for planetary geoscientists and their students to assist in identifying features found on rocks on planetary surfaces. In compiling this atlas, we have attempted to include features that have formed 'recently' and where the potential for modification by another geomorphic process is low. However, we acknowledge that this is, in fact, difficult to achieve when selecting rocks in their natural environment. We group breakdown features according to their formative environment and process. In selecting images for inclusion in the atlas we were mindful to cover a wide range of climatic zones. For example, in the weathering chapter, clast features are shown from locations such as the hyper-arid polar desert of Antarctica and the semi-arid canyons of central Australia. This is important as some

  2. Electric breakdowns of the "plasma capacitors" occurs on insulation coating of the ISS surface

    Science.gov (United States)

    Homin, Taras; Korsun, Anatolii

    High electric fields and currents are occurred in the spacecrafts plasma environment by onboard electric generators. Thus the high voltage solar array (SA) of the American segment of International Space Station (ISS) generates potential 160 V. Its negative pole is shorted to the frames of all the ISS segments. There is electric current between the SA and the frame through the plasma environment, i.e. electric discharge occurs. As a result a potential drop exists between the frames of all the ISS segments and the environmental plasma [1], which is cathode drop potential varphi _{c} defined. When ISS orbiting, the φc varies greatly in the range 0-100 V. A large area of the ISS frames and SA surface is coated with a thin dielectric film. Because of cathode drop potential the frame surfaces accumulate ion charges and the SA surfaces accumulate electron charges. These surfaces become plasma capacitors, which accumulate much charge and energy. Micrometeorite impacts or buildup of potential drop in excess of breakdown threshold varphi_{b} (varphi _{c} > varphi _{b} = 60 V) may cause breakdowns of these capacitors. Following a breakdown, the charge collected at the surfaces disperses and transforms into a layer of dense plasma [2]. This plasma environment of the spacecraft produces great pulsed electric fields E at the frame surfaces as well as heavy currents between construction elements which in turn induce great magnetic fields H. Therefore the conductive frame and the environmental plasma is plasma inductors. We have calculated that the densities of these pulsing and high-frequency fields E and H generated in the plasma environment of the spacecraft may exceed values hazardous to human. Besides, these fields must induce large electromagnetic impulses in the space-suit and in the power supply and control circuits of onboard systems. During astronaut’s space-suit activity, these fields will penetrate the space-suit and the human body with possible hazardous effects

  3. Biomarkers in Parkinson's disease (recent update).

    Science.gov (United States)

    Sharma, Sushil; Moon, Carolyn Seungyoun; Khogali, Azza; Haidous, Ali; Chabenne, Anthony; Ojo, Comfort; Jelebinkov, Miriana; Kurdi, Yousef; Ebadi, Manuchair

    2013-09-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder mostly affecting the aging population over sixty. Cardinal symptoms including, tremors, muscle rigidity, drooping posture, drooling, walking difficulty, and autonomic symptoms appear when a significant number of nigrostriatal dopaminergic neurons are already destroyed. Hence we need early, sensitive, specific, and economical peripheral and/or central biomarker(s) for the differential diagnosis, prognosis, and treatment of PD. These can be classified as clinical, biochemical, genetic, proteomic, and neuroimaging biomarkers. Novel discoveries of genetic as well as nongenetic biomarkers may be utilized for the personalized treatment of PD during preclinical (premotor) and clinical (motor) stages. Premotor biomarkers including hyper-echogenicity of substantia nigra, olfactory and autonomic dysfunction, depression, hyposmia, deafness, REM sleep disorder, and impulsive behavior may be noticed during preclinical stage. Neuroimaging biomarkers (PET, SPECT, MRI), and neuropsychological deficits can facilitate differential diagnosis. Single-cell profiling of dopaminergic neurons has identified pyridoxal kinase and lysosomal ATPase as biomarker genes for PD prognosis. Promising biomarkers include: fluid biomarkers, neuromelanin antibodies, pathological forms of α-Syn, DJ-1, amyloid β and tau in the CSF, patterns of gene expression, metabolomics, urate, as well as protein profiling in the blood and CSF samples. Reduced brain regional N-acetyl-aspartate is a biomarker for the in vivo assessment of neuronal loss using magnetic resonance spectroscopy and T2 relaxation time with MRI. To confirm PD diagnosis, the PET biomarkers include [(18)F]-DOPA for estimating dopaminergic neurotransmission, [(18)F]dG for mitochondrial bioenergetics, [(18)F]BMS for mitochondrial complex-1, [(11)C](R)-PK11195 for microglial activation, SPECT imaging with (123)Iflupane and βCIT for dopamine transporter, and urinary

  4. PET Metabolic Biomarkers for Cancer

    Science.gov (United States)

    Croteau, Etienne; Renaud, Jennifer M.; Richard, Marie Anne; Ruddy, Terrence D.; Bénard, François; deKemp, Robert A.

    2016-01-01

    The body’s main fuel sources are fats, carbohydrates (glucose), proteins, and ketone bodies. It is well known that an important hallmark of cancer cells is the overconsumption of glucose. Positron emission tomography (PET) imaging using the glucose analog 18F-fluorodeoxyglucose (18F-FDG) has been a powerful cancer diagnostic tool for many decades. Apart from surgery, chemotherapy and radiotherapy represent the two main domains for cancer therapy, targeting tumor proliferation, cell division, and DNA replication—all processes that require a large amount of energy. Currently, in vivo clinical imaging of metabolism is performed almost exclusively using PET radiotracers that assess oxygen consumption and mechanisms of energy substrate consumption. This paper reviews the utility of PET imaging biomarkers for the detection of cancer proliferation, vascularization, metabolism, treatment response, and follow-up after radiation therapy, chemotherapy, and chemotherapy-related side effects.

  5. Biomarkers in canine parvovirus enteritis.

    Science.gov (United States)

    Schoeman, J P; Goddard, A; Leisewitz, A L

    2013-07-01

    Canine parvovirus (CPV) enteritis has, since its emergence in 1978, remained a common and important cause of morbidity and mortality in young dogs. The continued incidence of parvoviral enteritis is partly due to the virus' capability to evolve into more virulent and resistant variants with significant local gastrointestinal and systemic inflammatory sequelae. This paper reviews current knowledge on historical-, signalment-, and clinical factors as well as several haematological-, biochemical- and endocrine parameters that can be used as diagnostic and prognostic biomarkers in CPV enteritis. These factors include season of presentation, purebred nature, bodyweight, vomiting, leukopaenia, lymphopaenia, thrombocytopaenia, hypercoagulability, hypercortisolaemia, hypothyroxinaemia, hypoalbuminaemia, elevated C-reactive protein and tumour necrosis factor, hypocholesterolaemia and hypocitrullinaemia. Factors contributing to the manifestations of CPV infection are multiple with elements of host, pathogen, secondary infections, underlying stressors and environment affecting severity and outcome. The availability of several prognosticators has made identification of patients at high risk of death and their subsequent targeted management more rewarding.

  6. Dissecting the Syndrome of Schizophrenia: Progress toward Clinically Useful Biomarkers

    Directory of Open Access Journals (Sweden)

    Brian Dean

    2011-01-01

    Full Text Available The search for clinically useful biomarkers has been one of the holy grails of schizophrenia research. This paper will outline the evolving notion of biomarkers and then outline outcomes from a variety of biomarkers discovery strategies. In particular, the impact of high-throughput screening technologies on biomarker discovery will be highlighted and how new or improved technologies may allow the discovery of either diagnostic biomarkers for schizophrenia or biomarkers that will be useful in determining appropriate treatments for people with the disorder. History tells those involved in biomarker research that the discovery and validation of useful biomarkers is a long process and current progress must always be viewed in that light. However, the approval of the first biomarker screen with some value in predicting responsiveness to antipsychotic drugs suggests that biomarkers can be identified and that these biomarkers that will be useful in diagnosing and treating people with schizophrenia.

  7. Dissecting the Syndrome of Schizophrenia: Progress toward Clinically Useful Biomarkers.

    Science.gov (United States)

    Dean, Brian

    2011-01-01

    The search for clinically useful biomarkers has been one of the holy grails of schizophrenia research. This paper will outline the evolving notion of biomarkers and then outline outcomes from a variety of biomarkers discovery strategies. In particular, the impact of high-throughput screening technologies on biomarker discovery will be highlighted and how new or improved technologies may allow the discovery of either diagnostic biomarkers for schizophrenia or biomarkers that will be useful in determining appropriate treatments for people with the disorder. History tells those involved in biomarker research that the discovery and validation of useful biomarkers is a long process and current progress must always be viewed in that light. However, the approval of the first biomarker screen with some value in predicting responsiveness to antipsychotic drugs suggests that biomarkers can be identified and that these biomarkers that will be useful in diagnosing and treating people with schizophrenia.

  8. Biomarkers in chronic adult hydrocephalus

    Directory of Open Access Journals (Sweden)

    Kitchen Neil D

    2006-10-01

    Full Text Available Abstract Awareness of the importance of chronic adult hydrocephalus has been raised again with the recent emergence of epidemiological studies. It is estimated that between 5 and 10% of patients suffering from dementia might, in fact, have chronic hydrocephalus. Although, surgical diversion of the cerebrospinal fluid (CSF represents the only known procedure able to treat the symptoms of this condition, the selection of surgical patients has always been problematic. In the last 40 years, we have become wiser in using appropriate diagnostic tests for the selection of these patients; however, the area of biological markers has so far been overlooked in this condition, in contrast to that for other neurodegenerative disorders and dementias. Biomarkers are biological substances that may be used to indicate either the onset or the presence, and the progression of a clinical condition, being closely linked to its pathophysiology. In such a setting they might assist in the more appropriate selection of patients for shunt surgery. In this article, we have reviewed research carried out in the last 25 years regarding the identification of serum and CSF biomarkers for chronic hydrocephalus, discussed the potential for each one, and finally discussed the limitations for use, as well as future directions and possibilities in this field. It is concluded that tumour-necrosis factor, tau protein, lactate, sulfatide and neurofilament triple protein are the most promising CSF markers for chronic hydrocephalus. At present however, none of these meet the criteria required to justify a change clinical practice. In the future, collaborative multi-centre projects will be needed to obtain more substantial data that overcome the problems that arise from small individual and uncoordinated studies.

  9. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    International Nuclear Information System (INIS)

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS

  10. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    Energy Technology Data Exchange (ETDEWEB)

    Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P., E-mail: singh@icet.msstate.edu

    2013-09-01

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS.

  11. Breakdown and Evolution of the Protective Oxide Scales of AISI 304 and AISI 316 Stainless Steels under High-Temperature Oxidation

    Directory of Open Access Journals (Sweden)

    K. A. Habib

    2011-01-01

    Full Text Available The failure of the protective oxide scales of AISI 304 and AISI 316 stainless steels has been studied and compared at 1,000°C in synthetic air. First, the isothermal thermogravimetric curves of both stainless steels were plotted to determine the time needed to reach the breakdown point. The different resistance of each stainless steel was interpreted on the basis of the nature of the crystalline phases formed, the morphology, and the surface structure as well as the cross-section structure of the oxidation products. The weight gain of AISI 304 stainless steel was about 8 times greater than that of AISI 316 stainless steel, and AISI 316 stainless steel reached the breakdown point about 40 times more slowly than AISI 304 stainless steel. In both stainless steels, reaching the breakdown point meant the loss of the protective oxide scale of Cr2O3, but whereas in AISI 304 stainless steel the Cr2O3 scale totally disappeared and exclusively Fe2O3 was formed, in AISI 316 stainless steel some Cr2O3 persisted and Fe3O4 was mainly formed, which means that AISI 316 stainless steel is more resistant to oxidation after the breakdown.

  12. Effect of physiologic hyperinsulinemia on skeletal muscle protein synthesis and breakdown in man

    International Nuclear Information System (INIS)

    Although insulin stimulates protein synthesis and inhibits protein breakdown in skeletal muscle in vitro, the actual contribution of these actions to its anabolic effects in man remains unknown. Using the forearm perfusion method together with systemic infusion of L-[ring-2,6-3H]phenylalanine and L-[1-14C]leucine, we measured steady state amino acid exchange kinetics across muscle in seven normal males before and in response to a 2-h intraarterial infusion of insulin. Postabsorptively, the muscle disposal (Rd) of phenylalanine (43 +/- 5 nmol/min per 100 ml forearm) and leucine (113 +/- 13) was exceeded by the concomitant muscle production (Ra) of these amino acids (57 +/- 5 and 126 +/- 9 nmol/min per dl, respectively), resulting in their net release from the forearm (-14 +/- 4 and -13 +/- 5 nmol/min per dl, respectively). In response to forearm hyperinsulinemia (124 +/- 11 microU/ml), the net balance of phenylalanine and leucine became positive (9 +/- 3 and 61 +/- 8 nmol/min per dl, respectively (P less than 0.005 vs. basal). Despite the marked increase in net balance, the tissue Rd for both phenylalanine (42 +/- 2) and leucine (124 +/- 9) was unchanged from baseline, while Ra was markedly suppressed (to 33 +/- 5 and 63 +/- 9 nmol/min per dl, respectively, P less than 0.01). Since phenylalanine is not metabolized in muscle (i.e., its only fates are incorporation into or release from protein) these results strongly suggest that in normal man, physiologic elevations in insulin promote net muscle protein anabolism primarily by inhibiting protein breakdown, rather than by stimulating protein synthesis

  13. Cardiac Biomarkers and Cycling Race

    Directory of Open Access Journals (Sweden)

    Caroline Le Goff, Jean-François Kaux, Sébastien Goffaux, Etienne Cavalier

    2015-06-01

    Full Text Available In cycling as in other types of strenuous exercise, there exists a risk of sudden death. It is important both to understand its causes and to see if the behavior of certain biomarkers might highlight athletes at risk. Many reports describe changes in biomarkers after strenuous exercise (Nie et al., 2011, but interpreting these changes, and notably distinguishing normal physiological responses from pathological changes, is not easy. Here we have focused on the kinetics of different cardiac biomarkers: creatin kinase (CK, creating kinase midbrain (CK-MB, myoglobin (MYO, highly sensitive troponin T (hs-TnT and N-terminal brain natriuretic peptide (NT-proBNP. The population studied was a group of young trained cyclists participating in a 177-km cycling race. The group of individuals was selected for maximal homogeneity. Their annual training volume was between 10,000 and 16,000 kilometers. The rhythm of races is comparable and averages 35 km/h, depending on the race’s difficulty. The cardiac frequency was recorded via a heart rate monitor. Three blood tests were taken. The first blood test, T0, was taken approximately 2 hours before the start of the race and was intended to gather values which would act as references for the following tests. The second blood test, T1, was realized within 5 minutes of their arrival. The third and final blood test, T3, was taken 3 hours following their arrival. The CK, CK-MB, MYO, hs-TnT and NT-proBNP were measured on the Roche Diagnostic modular E (Manhein, Germany. For the statistical analysis, an ANOVA and post hoc test of Scheffé were calculated with the Statistica Software version 9.1. We noticed an important significant variation in the cardiac frequency between T0 and T1 (p < 0.0001, T0 and T3 (p < 0.0001, and T1 and T3 (p < 0.01. Table 1 shows the results obtained for the different biomarkers. CK and CK-MB showed significant variation between T0-T1 and T0-T3 (p < 0.0001. Myoglobin increased significantly

  14. Molecular Imaging of Biomarkers in Breast Cancer

    Science.gov (United States)

    Ulaner, Gary A.; Riedl, Chris C.; Dickler, Maura N.; Jhaveri, Komal; Pandit-Taskar, Neeta; Weber, Wolfgang

    2016-01-01

    The success of breast cancer therapy is ultimately defined by clinical endpoints such as survival. It is valuable to have biomarkers that can predict the most efficacious therapies or measure response to therapy early in the course of treatment. Molecular imaging has a promising role in complementing and overcoming some of the limitations of traditional biomarkers by providing the ability to perform noninvasive, repeatable whole-body assessments. The potential advantages of imaging biomarkers are obvious and initial clinical studies have been promising, but proof of clinical utility still requires prospective multicenter clinical trials. PMID:26834103

  15. Research on Potential Biomarkers in Hereditary Haemorrhagic Telangiectasia

    Directory of Open Access Journals (Sweden)

    Luisa Maria Botella

    2015-03-01

    Full Text Available Hereditary Hemorrhagic Telangiectasia (HHT is a genetically heterogeneous disorder, involving mutations in two predominant genes known as Endoglin (ENG; HHT1 and Activin receptor like kinase 1 (ACVRL1/ALK1; HHT2, as well as in some less frequent genes, such as MADH4/SMAD4 (JP-HHT or BMP9/GDF2 (HHT5. The diagnosis of HHT patients currently remains at the clinical level, according to the Curaçao criteria, whereas the molecular diagnosis is used to confirm or rule out suspected HHT cases, especially when a well characterized index case is present in the family or in an isolated population. Unfortunately, many suspected patients do not present a clear HHT diagnosis or do not show pathogenic mutations in HHT genes, prompting the need to investigate additional biomarkers of the disease. Here, several HHT biomarkers and novel methodological approaches developed during the last years will be reviewed. On one hand, products detected in plasma or serum samples: soluble proteins (VEGF, TGF-β1, soluble endoglin, angiopoietin-2 and microRNA variants (miR-27a, miR-205, miR-210. On the other hand, differential HHT gene expression fingerprinting, Next Generation Sequencing (NGS of a panel of genes involved in HHT, and infrared spectroscopy combined with Artificial Neural Network (ANN patterns will also be reviewed. All these biomarkers might help to improve and refine HHT diagnosis by distinguishing from the non-HHT population.

  16. Developing recombinant antibodies for biomarker detection

    Energy Technology Data Exchange (ETDEWEB)

    Baird, Cheryl L.; Fischer, Christopher J.; Pefaur, Noah B.; Miller, Keith D.; Kagen, Jacob; Srivastava, Sudhir; Rodland, Karin D.

    2010-10-01

    Monoclonal antibodies (mAbs) have an essential role in biomarker validation and diagnostic assays. A barrier to pursuing these applications is the reliance on immunization and hybridomas to produce mAbs, which is time-consuming and may not yield the desired mAb. We recommend a process flow for affinity reagent production that utilizes combinatorial protein display systems (eg, yeast surface display or phage display) rather than hybridomas. These systems link a selectable phenotype-binding conferred by an antibody fragment-with a means for recovering the encoding gene. Recombinant libraries obtained from immunizations can produce high-affinity antibodies (<10 nM) more quickly than other methods. Non-immune libraries provide an alternate route when immunizations are not possible, or when suitable mAbs are not recovered from an immune library. Directed molecular evolution (DME) is an integral part of optimizing mAbs obtained from combinatorial protein display, but can also be used on hybridoma-derived mAbs. Variants can easily be obtained and screened to increase the affinity of the parent mAb (affinity maturation). We discuss examples where DME has been used to tailor affinity reagents to specific applications. Combinatorial protein display also provides an accessible method for identifying antibody pairs, which are necessary for sandwich-type diagnostic assays.

  17. / production

    Indian Academy of Sciences (India)

    François Arleo; Pol-Bernard Gossiaux; Thierry Gousset; Jörg Aichelin

    2003-04-01

    For more than 25 years /Ψ production has helped to sharpen our understanding of QCD. In proton induced reaction some observations are rather well understood while others are still unclear. The current status of the theory of /Ψ production will be sketched, paying special attention to the issues of formation time and /Ψ re-interaction in a nuclear medium.

  18. Thermodynamic efficiency of synthesis, storage and breakdown of the high-energy metabolites by photosynthetic microalgae

    International Nuclear Information System (INIS)

    Lipids and carbohydrates are employed in the nature to store internal energy due to the large number of the high energy atomic bonds in their structure. Internal energy stored in the bonds is used to fuel work producing engines or metabolic activity of living organisms. This paper investigates the thermodynamic efficiency of the glucose and lipid synthesis and breakdown by photosynthetic microalgae. Photosynthetic microalgae are able to convert 3.8% of the solar exergy into the chemical exergy of algal lipid. As the microalgae convert the first product of the photosynthesis, i.e. glucose, into lipid, 47–49% of the chemical exergy is lost. If the microalgal cell consumes the photosynthetically produced glucose for its own energy demand, then about 30% of the glucose exergy can be converted into work potential in case of immediate and short-term energy demands. Organism can convert about 22% of the glucose exergy into work potential after a long-term storage. If the algal lipid is harvested for biodiesel production and the produced biodiesel is combusted in a Diesel engine, then about 17% of the exergy of the photosynthetically produced glucose can be converted into useful work. Biodiesel is among the most popular renewable fuels. The lipids are harvested from their storage in the cells to produce biodiesel before following the lipid breakdown path of the cellular metabolism. Our analysis indicates that, extracting the first product of photosynthesis, i.e. glucose or glucose polymers instead of lipids may be more efficient thermodynamically, if new motors capable to extract their bond energy is developed. - Highlights: • Photosynthetic microalgae convert 3.8% of the solar exergy into the chemical exergy of algal lipid. • Converting the first product of the photosynthesis (glucose) into lipid causes 47–49% of exergy loss. • Organism can convert 30% of the glucose exergy into work potential for its own immediate or short-term energy demand. • Organism can

  19. Electronic individual breakdown of pension rights and/or transfer value

    CERN Multimedia

    Pension Fund

    2011-01-01

    Commencing this year, members of the personnel will be notified by e-mail of their annual breakdown of pension rights and/or transfer value. Each person receiving the e-mail notification will be invited to consult this breakdown by clicking on a link protected by AISlogin and a password. Benefits Service of the Pension Fund pension-benefits@cern.ch  

  20. Lowering effect of radioactive irradiation on breakdown voltage and electron avalanche pulse characteristics

    International Nuclear Information System (INIS)

    In the time resolving measurement of the growing process and breakdown of electron avalanche in a gap of uniform electric field, the phenomenon that DC breakdown voltage slightly lowered was observed when β ray was irradiated as the initial electron source, as compared with unirradiated condition. Beta source used is 90Sr-90Y of 2 mCi in radiative equilibrium. The experimental results and the examination are described in detail. In brief, the remarkable superposition of succeeding avalanche pulse over the preceeding avalanche pulse waveform was observed under the gap condition in which the breakdown voltage decreased in β-ray irradiation. Thus this superposition of avalanche pulses is considered as one of the causes of the breakdown voltage reduction. When β source is used as the initial electron source, the number of supplied initial electrons is very large as compared with unity, and at the same time, a great number of initial electrons can be supplied within the diffusion radius r of avalanche. Then the effect of initial electron number n0 was considered by employing a diagram for breakdown scheme. The transition from Townsend type breakdown to streamer type breakdown occurs owing to increasing n0, and in that condition, the breakdown voltage lowers slightly. (Wakatsuki, Y)

  1. The Analysis of Insulation Breakdown Probabilities by the Up-And-Down Method

    DEFF Research Database (Denmark)

    Vibholm (fratrådt), Svend; Thyregod, Poul

    1986-01-01

    This paper discusses the assessment of breakdown probability by means of the up-and-down method. The Dixon and Mood approximation to the maximum-likelihood estimate is compared with the exact maximum-likelihood estimate for a number of response patterns. Estimates of the 50D probability breakdown...

  2. Investigation of the current break-down phenomena in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K.; Srinivasamurthy, N.; Agrawal, B.L. [Power Systems Group, ISRO Satellite Centre, Bangalore (India)

    1996-08-15

    Observed reverse current-voltage characteristics of the single crystal silicon and gallium arsenide solar cells have been analyzed. Physical mechanisms behind the junction break-down in silicon cells and current break-down in gallium arsenide cells have been identified. Preliminary estimates of the diffusion capacitance in GaAs cells have been presented

  3. Gas breakdown limit and maximum acceleration gradient for inverse Cherenkov laser accelerator

    CERN Document Server

    Liu, Y; Cline, D

    1999-01-01

    Laser intensity thresholds for CO sub 2 laser-induced gas breakdown, such as tunneling, multiphoton, and cascade ionization have been estimated for the inverse Cherenkov accelerator experiment at the Brookhaven Accelerator Test Facility. The gas breakdown is dominated by cascade ionization and the maximum acceleration gradient is up to 300 MeV/m for a 3 ps CO sub 2 laser.

  4. THE ONSET OF ELECTRICAL BREAKDOWN IN DUST LAYERS: II. EFFECTIVE DIELECTRIC CONSTANT AND LOCAL FIELD ENHANCEMENT

    Science.gov (United States)

    Part 1 of the work has shown that electrical breakdown in dust layers obeys Paschen's Law, but occurs at applied field values which appear too small to initiate the breakdown. In this paper the authors show how an effective dielectric constant characterizing the dust layer can be...

  5. Vortex Breakdown Generated by off-axis Bifurcation in a cylinder with rotating covers

    DEFF Research Database (Denmark)

    Bisgaard, Anders; Brøns, Morten; Sørensen, Jens Nørkær

    2006-01-01

    Vortex breakdown of bubble type is studied for the flow in a cylinder with rotating top and bottom covers. For large ratios of the angular velocities of the covers, we observe numerically that the vortex breakdown bubble in the steady regime may occur through the creation of an off-axis vortex ring...

  6. The electrical breakdown strength of pre-stretched elastomers, with and without sample volume conservation

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed;

    2015-01-01

    In practice, the electrical breakdown strength of dielectric electroactive polymers (DEAPs)determines the upper limit for transduction. During DEAP actuation, the thickness of the elastomer decreases, and thus the electrical field increases and the breakdown process is determined by a coupled...

  7. Scaling law for direct current field emission-driven microscale gas breakdown

    International Nuclear Information System (INIS)

    The effects of field emission on direct current breakdown in microscale gaps filled with an ambient neutral gas are studied numerically and analytically. Fundamental numerical experiments using the particle-in-cell/Monte Carlo collisions method are used to systematically quantify microscale ionization and space-charge enhancement of field emission. The numerical experiments are then used to validate a scaling law for the modified Paschen curve that bridges field emission-driven breakdown with the macroscale Paschen law. Analytical expressions are derived for the increase in cathode electric field, total steady state current density, and the ion-enhancement coefficient including a new breakdown criterion. It also includes the effect of all key parameters such as pressure, operating gas, and field-enhancement factor providing a better predictive capability than existing microscale breakdown models. The field-enhancement factor is shown to be the most sensitive parameter with its increase leading to a significant drop in the threshold breakdown electric field and also to a gradual merging with the Paschen law. The proposed scaling law is also shown to agree well with two independent sets of experimental data for microscale breakdown in air. The ability to accurately describe not just the breakdown voltage but the entire pre-breakdown process for given operating conditions makes the proposed model a suitable candidate for the design and analysis of electrostatic microscale devices.

  8. Effect of temperature on the electric breakdown strength of dielectric elastomer

    Science.gov (United States)

    Liu, Lei; Chen, Hualing; Sheng, Junjie; Zhang, Junshi; Wang, Yongquan; Jia, Shuhai

    2014-03-01

    DE (dielectric elastomer) is one of the most promising artificial muscle materials for its large strain over 100% under driving voltage. However, to date, dielectric elastomer actuators (DEAs) are prone to failure due to the temperature-dependent electric breakdown. Previously studies had shown that the electrical breakdown strength was mainly related to the temperature-dependent elasticity modulus and the permittivity of dielectric substances. This paper investigated the influence of ambient temperature on the electric breakdown strength of DE membranes (VHB4910 3M). The electric breakdown experiment of the DE membrane was conducted at different ambient temperatures and pre-stretch levels. The real breakdown strength was obtained by measuring the deformation and the breakdown voltage simultaneously. Then, we found that with the increase of the environment temperature, the electric breakdown strength decreased obviously. Contrarily, the high pre-stretch level led to the large electric breakdown strength. What is more, we found that the deformations of DEs were strongly dependent on the ambient temperature.

  9. Design Flaws and Service System Breakdowns: Learning from Systems Thinking

    Directory of Open Access Journals (Sweden)

    David Ing

    2014-12-01

    Full Text Available In what ways might systems thinking be helpful to designers?  In the 21st century, the types of project with which designers have become engaged has expanded to include service systems.  Service systems are typically composites of mechanisms, organisms, human beings and ecologies.  Systems thinking is a perspective with theories, methods and practices that enables transcending disciplinary boundaries.  Application of systems thinking in designing a service system can aid in surfacing potential flaws and/or anticipating future breakdowns in functions, structures and/or processes. Designers and systems thinkers should work together to improve the nature of service systems.  As a starter set into these conversations, seven conditions are proposed as a starting context.  These conditions are presented neither as rigourously defined nor as exhaustive, but as an entry point into future joint engagement.

  10. Laser-induced breakdown spectroscopy theory and applications

    CERN Document Server

    Perini, Umberto

    2014-01-01

    This book deals with the Laser-Induced Breakdown Spectroscopy (LIBS), a widely used atomic emission spectroscopy technique for elemental analysis of materials. It is based on the use of a high-power, short pulse laser excitation. The book is divided into two main sections: the first one concerning theoretical aspects of the technique, the second one describing the state of the art in applications of the technique in different scientific/technological areas. Numerous examples of state of the art applications provide the readers an almost complete scenario of the LIBS technique. The LIBS theoretical aspects are reviewed. The book helps the readers who are less familiar with the technique to understand the basic principles. Numerous examples of state of the art applications give an almost complete scenario of the LIBS technique potentiality. These examples of applications may have a strong impact on future industrial utilization. The authors made important contributions to the development of this field.

  11. Kinetic modeling of the Townsend breakdown in argon

    Energy Technology Data Exchange (ETDEWEB)

    Macheret, S. O.; Shneider, M. N. [Department of Mechanical and Aerospace Engineering, Princeton University, D-414 Engineering Quadrangle, Princeton, New Jersey 08544 (United States)

    2013-10-15

    Kinetic modeling of the Townsend breakdown in argon was performed in the “forward-back” approximation. The kinetic model was found to adequately describe the left branch of the Paschen curve, and the important role of ionization by fast ions and atoms near the cathode, as well as the increase in secondary emission coefficient in strong electric fields described in the literature, was confirmed. The modeling also showed that the electron energy distribution function develops a beam of high-energy electrons and that the runaway effect, i.e., the monotonic increase of the mean electron energy with the distance from the cathode, occurs at the left branch of the Paschen curve.

  12. Laser-induced breakdown spectroscopy fundamentals and applications

    CERN Document Server

    Noll, Reinhard

    2012-01-01

    This book is a comprehensive source of the fundamentals, process parameters, instrumental components and applications of laser-induced breakdown spectroscopy (LIBS). The effect of multiple pulses on material ablation, plasma dynamics and plasma emission is presented. A heuristic plasma modeling allows to simulate complex experimental plasma spectra. These methods and findings form the basis for a variety of applications to perform quantitative multi-element analysis with LIBS. These application potentials of LIBS have really boosted in the last years ranging from bulk analysis of metallic alloys and non-conducting materials, via spatially resolved analysis and depth profiling covering measuring objects in all physical states: gaseous, liquid and solid. Dedicated chapters present LIBS investigations for these tasks with special emphasis on the methodical and instrumental concepts as well as the optimization strategies for a quantitative analysis. Requirements, concepts, design and characteristic features of LI...

  13. Time domain simulations of preliminary breakdown pulses in natural lightning

    CERN Document Server

    Carlson, B E; Bitzer, P; Christian, H

    2016-01-01

    Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mecha...

  14. Degeneracy breakdown as a source of supernovae Ia

    CERN Document Server

    Clavelli, L

    2016-01-01

    We pursue the investigation of a model for sub-Chandrasekhar supernovae Ia explosions (SNIa) in which the energy stored in the Pauli tower is released to trigger a nuclear deflagration. The simplest physical model for such a degeneracy breakdown is a phase transition to an exactly supersymmetric state in which the scalar partners of protons, neutrons, and leptons become degenerate with the familiar fermions of our world as in the supersymmetric standard model with susy breaking parameters relaxed to zero. We focus on the ability of the susy phase transition model to fit the total SNIa rate as well as the delay time distribution of SNIa after the birth of a progenitor white dwarf. We also study the ejected mass distribution and its correlation with delay time. Finally, we discuss the expected SNIa remnant in the form of a black hole of Jupiter mass or lower and the prospects for detecting such remnants.

  15. Kertész line of thermally activated breakdown phenomena

    KAUST Repository

    Yoshioka, Naoki

    2010-11-12

    Based on a fiber bundle model we substantially extend the phase-transition analogy of thermally activated breakdown of homogeneous materials. We show that the competition of breaking due to stress enhancement and due to thermal fluctuations leads to an astonishing complexity of the phase space of the system: varying the load and the temperature a phase boundary emerges, separating a Griffith-type regime of abrupt failure analogous to first-order phase transitions from disorder dominated fracture where a spanning cluster of cracks emerges. We demonstrate that the phase boundary is the Kertész line of the system along which thermally activated fracture appears as a continuous phase transition analogous to percolation. The Kertész line has technological relevance setting the boundary of safe operation for construction components under high thermal loads. © 2010 The American Physical Society.

  16. Detection of early caries by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-07-01

    To improve sensitivity of dental caries detection by laser-induced breakdown spectroscopy (LIBS) analysis, it is proposed to utilize emission peaks in the ultraviolet. We newly focused on zinc whose emission peaks exist in ultraviolet because zinc exists at high concentration in the outer layer of enamel. It was shown that by using ratios between heights of an emission peak of Zn and that of Ca, the detection sensitivity and stability are largely improved. It was also shown that early caries are differentiated from healthy part by properly setting a threshold in the detected ratios. The proposed caries detection system can be applied to dental laser systems such as ones based on Er:YAG-lasers. When ablating early caries part by laser light, the system notices the dentist that the ablation of caries part is finished. We also show the intensity of emission peaks of zinc decreased with ablation with Er:YAG laser light.

  17. Apparatus, system, and method for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  18. Study of breakdown in an ablative pulsed plasma thruster

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Tiankun; Wu, Zhiwen; Liu, Xiangyang; Xie, Kan; Wang, Ningfei; Cheng, Yue [School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 (China)

    2015-10-15

    Breakdown in ablative pulsed plasma thrusters (APPTs) must be studied in order to design new types of APPTs and measure particular parameters. In this paper, we studied a parallel-plate ablative pulsed plasma thruster that used a coaxial semiconductor spark plug. By operating the APPT about 500 times with various capacitor voltages and electrode gaps, we measured and analyzed the voltage of the spark plug, the voltage between the electrodes, and the discharge current. These experiments revealed a time delay (∼1–10 μs) between spark plug ignition and capacitor discharge, which may affect the performance of high-pulsing-rate (>10 kHz) and double-discharge APPTs, and the measurements of some of the APPT parameters. The delay time decreased as the capacitor voltage increased, and it increased with an increasing electrode gap and increasing number of ignitions. We explain our results through a simple theoretical analysis.

  19. Mitochondrial endonuclease G mediates breakdown of paternal mitochondria upon fertilization.

    Science.gov (United States)

    Zhou, Qinghua; Li, Haimin; Li, Hanzeng; Nakagawa, Akihisa; Lin, Jason L J; Lee, Eui-Seung; Harry, Brian L; Skeen-Gaar, Riley Robert; Suehiro, Yuji; William, Donna; Mitani, Shohei; Yuan, Hanna S; Kang, Byung-Ho; Xue, Ding

    2016-07-22

    Mitochondria are inherited maternally in most animals, but the mechanisms of selective paternal mitochondrial elimination (PME) are unknown. While examining fertilization in Caenorhabditis elegans, we observed that paternal mitochondria rapidly lose their inner membrane integrity. CPS-6, a mitochondrial endonuclease G, serves as a paternal mitochondrial factor that is critical for PME. We found that CPS-6 relocates from the intermembrane space of paternal mitochondria to the matrix after fertilization to degrade mitochondrial DNA. It acts with maternal autophagy and proteasome machineries to promote PME. Loss of cps-6 delays breakdown of mitochondrial inner membranes, autophagosome enclosure of paternal mitochondria, and PME. Delayed removal of paternal mitochondria causes increased embryonic lethality, demonstrating that PME is important for normal animal development. Thus, CPS-6 functions as a paternal mitochondrial degradation factor during animal development.

  20. Elemental Analysis of Soils by Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Gondal, Mohammed Ashraf; Dastageer, Mohamed A.

    The chemical and elemental composition of soil is very complex as it contains many constituents like minerals, organic matters, living organisms, fossils, air and water. Considering the diversity of soil contents, quality and usability, a systematic scientific study on the elemental and chemical composition of soil is very important. In order to study the chemical composition of soil, Laser induced breakdown spectroscopy (LIBS) has been applied recently. The important features of LIBS system and its applications for the measurement of nutrients in green house soil, on-line monitoring of remediation process of chromium polluted soil, determination of trace elements in volcanic erupted soil samples collected from ancient cenozoic lava eruption sites and detection of toxic metals in Gulf war oil spill contaminated soil using LIBS are described in this chapter.

  1. Evidence of electric breakdown induced by bubbles in liquid argon

    CERN Document Server

    Bay, F; Murphy, S; Resnati, F; Rubbia, A; Sergiampietri, F; Wu, S

    2014-01-01

    We report on the results of a high voltage test in liquid argon in order to measure its dielectric rigidity. Under stable conditions and below the boiling point, liquid argon was found to sustain a uniform electric field of 100 kV/cm, applied in a region of 20 cm$^2$ area across 1 cm thick gap. When the liquid is boiling, breakdowns may occur at electric fields as low as 40 kV/cm. This test is one of the R&D efforts towards the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER) as proposed Liquid Argon Time Projection Chamber (LAr TPC) for the LBNO observatory for neutrino physics, astrophysics and nucleon decay searches.

  2. Gas breakdown limits for inverse Cherenkov laser accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y. [California Univ., Los Angeles, CA (United States). Dept. of Physics; Pogorelsky, I.V. [Brookhaven National Lab., Upton, NY (United States)

    1995-07-01

    The probability of avalanche, tunneling and multiphoton ionization induced by a CO{sub 2} laser in H{sub 2} gas has been calculated. Laser light screening by a self-induced plasma density gradient is considered as the limiting factor for upscaling a CO{sub 2} laser-driven Inverse Cherenkov Laser Accelerator beyond 650 MeV/m. However, in near-resonance inverse Cherenkov acceleration where a shorter wavelength laser is used at a wavelength near the resonance of the gas (e.g. 248nm in H{sub 2}), the formation of a plasma is not a problem because the plasma density is below the critical density. In that case, the laser beam propagates unaffected through the plasma and the acceleration gradient is not limited by gas breakdown. Gradients > 1 GeV/m are possible.

  3. Domain wall mobility, stability and Walker breakdown in magnetic nanowires

    Science.gov (United States)

    Mougin, A.; Cormier, M.; Adam, J. P.; Metaxas, P. J.; Ferré, J.

    2007-06-01

    We present an analytical calculation of the velocity of a single 180° domain wall in a magnetic structure with reduced thickness and/or lateral dimension under the combined action of an external applied magnetic field and an electrical current. As for the case of field-induced domain wall propagation in thick films, two motion regimes with different mobilities are obtained, below and far above the so-called Walker field. Additionally, for the case of current induced motion, a Walker-like current density threshold is defined. The threshold field and current density, stating the wall's internal structure stability, differ from those in thick films; both are reduced by the same geometrical demagnetising factor which accounts for the confinement. This points out the fact that the velocity dependence over an extended field/current range and the knowledge of the Walker breakdown are mandatory to draw conclusions about the phenomenological Gilbert damping parameter tuning the magnetisation dynamics.

  4. Laser induced breakdown spectroscopy for the discrimination of Candida strains.

    Science.gov (United States)

    Manzoor, S; Ugena, L; Tornero-Lopéz, J; Martín, H; Molina, M; Camacho, J J; Cáceres, J O

    2016-08-01

    The present study reports the evaluation of Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) for the discrimination of different strains of various species of Candida. This genus of yeast was selected due to its medical relevance as it is commonly found in cases of fungal infection in humans. Twenty one strains belonging to seven species of Candida were included in the study. Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) was employed as a complementary technique to provide information about elemental composition of Candida cells. The use of LIBS spectra in combination with optimized NN models provided reliable discrimination among the distinct Candida strains with a high spectral correlation index for the samples analyzed, without any false positive or false negative. Therefore, this study indicates that LIBS-NN based methodology has the potential to be used as fast fungal identification or even diagnostic method. PMID:27216662

  5. The Role of Sphingomyelin Breakdown in Measles Virus Immunmodulation

    Directory of Open Access Journals (Sweden)

    Elita Avota

    2014-06-01

    Full Text Available Measles virus (MV efficiently causes generalized immunosuppression which accounts to a major extent for cases of measles-asscociated severe morbidity and mortality. MV infections alter many functions of antigen presenting cells (APC (dendritic cells (DCs and lymphocytes, yet many molecular targets of the virus remain poorly defined. Cellular interactions and effector functions of DCs and lymphocytes are regulated by surface receptors. Associating with other proteins involved in cell signaling, receptors form part of receptosomes that respond to and transmit external signals through dynamic interctions with the cytoskeleton. Alterations in the composition and metabolism of membrane sphingolipids have a substantial impact on both processes. In this review we focus on the regulation of sphingomyelinase activity and ceramide release in cells exposed to MV and discuss the immunosuppressive role of sphingomyelin breakdown induced by MV.

  6. Growth hormone-mediated breakdown of body fat

    DEFF Research Database (Denmark)

    Johansen, T.; Malmlöf, K.; Richelsen, Bjørn;

    2003-01-01

    Lipid storage and breakdown is mainly controlled by lipoprotein lipase and hormone-sensitive lipase. The aim of this work was to elucidate whether growth hormone mediated loss of adipose tissue involves a concerted action on tissue lipases, and to what degree such events are modulated by dietary...... fatty acids, glycerol and cholesterol were reduced by growth hormone, and in combination with restricted high-fat feeding, triglyceride levels improved too. We conclude that growth hormone inhibits lipid storage in adipose tissue by reducing both lipoprotein lipase activity and insulin's inhibitory...... action on hormone-sensitive lipase. We also propose that growth hormone's effects on tissue lipases and blood lipids are modulated by dietary regimen....

  7. Breakdown of Counterflow Superfluidity in a Disordered Quantum Hall Bilayer

    Directory of Open Access Journals (Sweden)

    D. K. K. Lee

    2011-01-01

    Full Text Available We present a theory for the regime of coherent interlayer tunneling in a disordered quantum Hall bilayer at total filling factor one, allowing for the effect of static vortices. We find that the system consists of domains of polarized superfluid phase. Injected currents introduce phase slips between the polarized domains which are pinned by disorder. We present a model of saturated tunneling domains that predicts a critical current for the breakdown of coherent tunneling that is extensive in the system size. This theory is supported by numerical results from a disordered phase model in two dimensions. We also discuss how our picture might be used to interpret experiments in the counterflow geometry and in two-terminal measurements.

  8. Urinary tobacco smoke-constituent biomarkers for assessing risk of lung cancer.

    Science.gov (United States)

    Yuan, Jian-Min; Butler, Lesley M; Stepanov, Irina; Hecht, Stephen S

    2014-01-15

    Tobacco-constituent biomarkers are metabolites of specific compounds present in tobacco or tobacco smoke. Highly reliable analytic methods, based mainly on mass spectrometry, have been developed for quantitation of these biomarkers in both urine and blood specimens. There is substantial interindividual variation in smoking-related lung cancer risk that is determined in part by individual variability in the uptake and metabolism of tobacco smoke carcinogens. Thus, by incorporating these biomarkers in epidemiologic studies, we can potentially obtain a more valid and precise measure of in vivo carcinogen dose than by using self-reported smoking history, ultimately improving the estimation of smoking-related lung cancer risk. Indeed, we have demonstrated this by using a prospective study design comparing biomarker levels in urine samples collected from smokers many years before their development of cancer versus those in their smoking counterparts without a cancer diagnosis. The following urinary metabolites were associated with lung cancer risk, independent of smoking intensity and duration: cotinine plus its glucuronide, a biomarker of nicotine uptake; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL), a biomarker of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK); and r-1-,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), a biomarker of polycyclic aromatic hydrocarbons (PAH). These results provide several possible new directions for using tobacco smoke-constituent biomarkers in lung cancer prevention, including improved lung cancer risk assessment, intermediate outcome determination in prevention trials, and regulation of tobacco products.

  9. Dynamics of optical breakdown in air induced by single and double nanosecond laser pulses

    Science.gov (United States)

    Mahdieh, Mohammad Hossein; Akbari Jafarabadi, Marzieh

    2015-12-01

    In this paper, an optical breakdown in air induced by single and double nanosecond laser pulses was studied. A high power Nd:YAG laser beam was used for producing optical breakdown plasma in the air. The dynamics of breakdown plasma were studied using an optical probe beam. A portion of the laser beam was used, as the probe beam and was aligned to propagate (perpendicular to the pump beam) through the breakdown region. The transmission of the probe beam (through the breakdown region) was temporally measured for both single and double pulse irradiations. The results were used to describe the evolution of the induced plasma in both conditions. These results show that the plasma formation time and its absorptivity are strongly dependent on the single or double pulse configurations.

  10. Quantitative statistical analysis of dielectric breakdown in zirconia-based self-assembled nanodielectrics.

    Science.gov (United States)

    Schlitz, Ruth A; Ha, Young-geun; Marks, Tobin J; Lauhon, Lincoln J

    2012-05-22

    Uniformity of the dielectric breakdown voltage distribution for several thicknesses of a zirconia-based self-assembled nanodielectric was characterized using the Weibull distribution. Two regimes of breakdown behavior are observed: self-assembled multilayers >5 nm thick are well described by a single two-parameter Weibull distribution, with β ≈ 11. Multilayers ≤5 nm thick exhibit kinks on the Weibull plot of dielectric breakdown voltage, suggesting that multiple characteristic mechanisms for dielectric breakdown are present. Both the degree of uniformity and the effective dielectric breakdown field are observed to be greater for one layer than for two layers of Zr-SAND, suggesting that this multilayer is more promising for device applications.

  11. Experimental Study on the Dielectric Breakdown Voltage of the Insulating Oil Mixed with Magnetic Nanoparticles

    Science.gov (United States)

    Lee, Jong-Chul; Kim, Woo-Young

    In this study, we have measured the dielectric breakdown voltage of transformer oil-based nanofluids in accordance with IEC 156 standard and have investigated the dielectric breakdown performance with the application of an external magnetic field and different volume concentrations of magnetic nanoparticles. It is confirmed that the dielectric breakdown voltage of pure transformer oil is about 10 kV with a gap distance of 1 mm between electrodes. In the case of our transformer oil-based nanofluids with 0.08% magnetic nanoparticles in the fluid), the dielectric breakdown voltage is three times higher than that of pure transformer oil. Furthermore, when the external magnetic field is applied under the experimental vessel, the dielectric breakdown voltage of the nanofluids is above 40 kV, which is 30% higher than that without the external magnetic field.

  12. Gas Breakdown of Radio Frequency Glow Discharges in Helium at near Atmospheric Pressure

    Science.gov (United States)

    Liu, Xinkun; Xu, Jinzhou; Cui, Tongfei; Guo, Ying; Zhang, Jing; Shi, Jianjun

    2013-07-01

    A one-dimensional self-consistent fluid model was developed for radio frequency glow discharge in helium at near atmospheric pressure, and was employed to study the gas breakdown characteristics in terms of breakdown voltage. The effective secondary electron emission coefficient and the effective electric field for ions were demonstrated to be important for determining the breakdown voltage of radio frequency glow discharge at near atmospheric pressure. The constant of A was estimated to be 64±4 cm-1Torr-1, which was proportional to the first Townsend coefficient and could be employed to evaluate the gas breakdown voltage. The reduction in the breakdown voltage of radio frequency glow discharge with excitation frequency was studied and attributed to the electron trapping effect in the discharge gap.

  13. Dynamics of optical breakdown in air induced by single and double nanosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Mahdieh, Mohammad Hossein, E-mail: mahdm@iust.ac.ir; Akbari Jafarabadi, Marzieh [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 1684613114 (Iran, Islamic Republic of)

    2015-12-15

    In this paper, an optical breakdown in air induced by single and double nanosecond laser pulses was studied. A high power Nd:YAG laser beam was used for producing optical breakdown plasma in the air. The dynamics of breakdown plasma were studied using an optical probe beam. A portion of the laser beam was used, as the probe beam and was aligned to propagate (perpendicular to the pump beam) through the breakdown region. The transmission of the probe beam (through the breakdown region) was temporally measured for both single and double pulse irradiations. The results were used to describe the evolution of the induced plasma in both conditions. These results show that the plasma formation time and its absorptivity are strongly dependent on the single or double pulse configurations.

  14. Electromechanical Breakdown of Barrier-Type Anodized Aluminum Oxide Thin Films Under High Electric Field Conditions

    Science.gov (United States)

    Chen, Jianwen; Yao, Manwen; Yao, Xi

    2016-02-01

    Barrier-type anodized aluminum oxide (AAO) thin films were formed on a polished aluminum substrate via electrochemical anodization in 0.1 mol/L aqueous solution of ammonium pentaborate. Electromechanical breakdown occurred under high electric field conditions as a result of the accumulation of mechanical stress in the film-substrate system by subjecting it to rapid thermal treatment. Before the breakdown event, the electricity of the films was transported in a highly nonlinear way. Immediately after the breakdown event, dramatic cracking of the films occurred, and the cracks expanded quickly to form a mesh-like dendrite network. The breakdown strength was significantly reduced because of the electromechanical coupling effect, and was only 34% of the self-healing breakdown strength of the AAO film.

  15. Study of predicting breakdown voltage of stator insulation in generator based on BP neural network

    Institute of Scientific and Technical Information of China (English)

    Jiang Yuao; Zhang Aide; Liu Libing; Du Yu; Gao Naikui; Peng Zongren

    2007-01-01

    The breakdown voltage plays an important role in evaluating residual life of stator insulation in generator. In this paper, we discussed BP neural network that was used to predict the breakdown voltage of stator insulation in generator of 300 MW/18 kV. At first the neural network has been trained by the samples that include the varieties of dielectric loss factor tanδ, the partial discharge parameters and breakdown voltage. Then we tried to predict the breakdown voltage of samples and stator insulations subjected to multi-stress aging by the trained neural network. We found that it's feasible and accurate to predict the voltage. This method can be applied to predict breakdown voltage of other generators which have the same insulation structure and material.

  16. Backside optimization for improving avalanche breakdown behavior of 4.5 kV IGBT

    International Nuclear Information System (INIS)

    The static avalanche breakdown behavior of 4.5 kV high-voltage IGBT is studied by theory analysis and experiment. The avalanche breakdown behaviors of the 4.5 kV IGBTs with different backside structures are investigated and compared by using the curve tracer. The results show that the snap back behavior of the breakdown waveform is related to the bipolar PNP gain, which leads to the deterioration of the breakdown voltage. There are two ways to optimize the backside structure, one is increasing the implant dose of the N+ buffer layer, the other is decreasing the implant dose of the P+ collector layer. It is found that the optimized structure is effective in suppressing the snap back behavior and improving the breakdown characteristic of high voltage IGBT. (paper)

  17. Backside optimization for improving avalanche breakdown behavior of 4.5 kV IGBT

    Science.gov (United States)

    Xiaoli, Tian; Jiang, Lu; Yuan, Teng; Wenliang, Zhang; Shuojin, Lu; Yangjun, Zhu

    2015-03-01

    The static avalanche breakdown behavior of 4.5 kV high-voltage IGBT is studied by theory analysis and experiment. The avalanche breakdown behaviors of the 4.5 kV IGBTs with different backside structures are investigated and compared by using the curve tracer. The results show that the snap back behavior of the breakdown waveform is related to the bipolar PNP gain, which leads to the deterioration of the breakdown voltage. There are two ways to optimize the backside structure, one is increasing the implant dose of the N+ buffer layer, the other is decreasing the implant dose of the P+ collector layer. It is found that the optimized structure is effective in suppressing the snap back behavior and improving the breakdown characteristic of high voltage IGBT. Project supported by the National Major Science and Technology Special Project of China (No. 2011ZX02503-003).

  18. CSF Biomarkers for Alzheimer's Disease Diagnosis

    Directory of Open Access Journals (Sweden)

    A. Anoop

    2010-01-01

    Full Text Available Alzheimer's disease (AD is the most common form of dementia that affects several million people worldwide. The major neuropathological hallmarks of AD are the presence of extracellular amyloid plaques that are composed of Aβ40 and Aβ42 and intracellular neurofibrillary tangles (NFT, which is composed of hyperphosphorylated protein Tau. While the amyloid plaques and NFT could define the disease progression involving neuronal loss and dysfunction, significant cognitive decline occurs before their appearance. Although significant advances in neuroimaging techniques provide the structure and physiology of brain of AD cases, the biomarker studies based on cerebrospinal fluid (CSF and plasma represent the most direct and convenient means to study the disease progression. Biomarkers are useful in detecting the preclinical as well as symptomatic stages of AD. In this paper, we discuss the recent advancements of various biomarkers with particular emphasis on CSF biomarkers for monitoring the early development of AD before significant cognitive dysfunction.

  19. Early Detection Biomarkers for Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Sreeja Sarojini

    2012-01-01

    Full Text Available Despite the widespread use of conventional and contemporary methods to detect ovarian cancer development, ovarian cancer remains a common and commonly fatal gynecological malignancy. The identification and validation of early detection biomarkers highly specific to ovarian cancer, which would permit development of minimally invasive screening methods for detecting early onset of the disease, are urgently needed. Current practices for early detection of ovarian cancer include transvaginal ultrasonography, biomarker analysis, or a combination of both. In this paper we review recent research on novel and robust biomarkers for early detection of ovarian cancer and provide specific details on their contributions to tumorigenesis. Promising biomarkers for early detection of ovarian cancer include KLK6/7, GSTT1, PRSS8, FOLR1, ALDH1, and miRNAs.

  20. Cancer Biomarkers | Division of Cancer Prevention

    Science.gov (United States)

    This group promotes research to identify, develop, and validate biological markers for early cancer detection and cancer risk assessment. | Research to identify, develop and validate biomarkers for early cancer detection and risk assessment.

  1. The development and applications of biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Normandy, J.; Peeters, J. [eds.

    1994-04-15

    This report is a compilation of submitted abstracts of scientific papers presented at the second Department of Energy-supported workshop on the use and applications of biomarkers held in Santa Fe, New Mexico, from April 26--29, 1994. The abstracts present a synopsis of the latest scientific developments in biomarker research and how these developments meet with the practical needs of the occupational physician as well as the industrial hygienist and the health physicist. In addition to considering the practical applications and potential benefits of this promising technology, the potential ethical and legal ramifications of using biomarkers to monitor workers are discussed. The abstracts further present insights on the present benefits that can be derived from using biomarkers as well as a perspective on what further research is required to fully meet the needs of the medical community.

  2. Statistical design and evaluation of biomarker studies.

    Science.gov (United States)

    Dobbin, Kevin K

    2014-01-01

    We review biostatistical aspects of biomarker studies, including design and analysis issues, covering the range of settings required for translational research-from early exploratory studies through clinical trials.

  3. CSF biomarkers in neurodegenerative and vascular dementias.

    Science.gov (United States)

    Llorens, Franc; Schmitz, Matthias; Ferrer, Isidro; Zerr, Inga

    2016-01-01

    Neurodegenerative diseases with abnormal protein aggregates such as Alzheimer's disease, tauopathies, synucleinopathies, and prionopathies, together with vascular encephalopathies, are cause of cognitive impairment and dementia. Identification of reliable biomarkers in biological fluids, particularly in the cerebrospinal fluid (CSF), is of extreme importance in optimizing the precise early clinical diagnosis of distinct entities and predicting the outcome in particular settings. In addition, the study of CSF biomarkers is useful to identify and monitor the underlying pathological processes developing in the central nervous system of affected individuals. Evidence suggests that levels of key CSF molecules correlate, in some circumstances, with prediction, disease progression, and severity of cognitive decline. Correlation of CSF markers and underlying pathological molecular substrates in brain is an exciting field for further study. However, while some dementias such as Creutzfeldt-Jakob disease have accurate CSF biomarkers, other disease types such as dementia with Lewy bodies, vascular dementia, and frontotemporal dementia lack reliable biomarkers for their specific clinical diagnosis. PMID:27016008

  4. Cardiorenal biomarkers in acute heart failure

    Institute of Scientific and Technical Information of China (English)

    Rajiv Choudhary; Dipika Gopal; Ben A. Kipper; Alejandro De La Parra Landa; Hermineh Aramin

    2012-01-01

    Managing patients with heart failure (HF) is a challenging task within itself, but the presence of associated worsening renal function can greatly increase mortality and morbidity. Early diagnosis and treatment is the key to prevent re-hospitalizations and reduce healthcare costs. Biomarkers have long been established as highly sensitive and specific tools in diagnosing and prognosticating patients with HF. Reflecting distinct pathophysiological events and ongoing cellular insult, biomarkers have been proven superior to conventional laboratory tests. Availability of better assays and rapid analysis has allowed the use of biomarkers as point-of-care tests in the emergency department and at the patient's bed-side. Acute HF patients often go on to develop worsening renal function, termed as acute cardiorenal syndrome. The growing breadth of studies has shown the implications of combining multiple biomarkers to better chart outcomes and produce desirable results in such patients.

  5. The development and applications of biomarkers

    International Nuclear Information System (INIS)

    This report is a compilation of submitted abstracts of scientific papers presented at the second Department of Energy-supported workshop on the use and applications of biomarkers held in Santa Fe, New Mexico, from April 26--29, 1994. The abstracts present a synopsis of the latest scientific developments in biomarker research and how these developments meet with the practical needs of the occupational physician as well as the industrial hygienist and the health physicist. In addition to considering the practical applications and potential benefits of this promising technology, the potential ethical and legal ramifications of using biomarkers to monitor workers are discussed. The abstracts further present insights on the present benefits that can be derived from using biomarkers as well as a perspective on what further research is required to fully meet the needs of the medical community

  6. Melanoma biomarkers: Vox clamantis in deserto (Review)

    OpenAIRE

    AL-SHAER, MAYS; GOLLAPUDI, DIVYA; PAPAGEORGIO, CHRIS

    2010-01-01

    Detecting malignant melanoma at an early stage, monitoring therapy, predicting recurrence and identifying patients at risk for metastasis continue to be a challenging and demanding objective. The last two decades have witnessed innovations in the field of melanoma biomarkers. However, global agreement concerning monitoring and early detection has yet to be reached. This is a review of the current literature regarding melanoma biomarkers including demographic, clinical, pathological and molecu...

  7. Current status of biomarker research in neurology

    OpenAIRE

    Polivka, Jiri; Krakorova, Kristyna; Peterka, Marek; Topolcan, Ondrej

    2016-01-01

    Neurology is one of the typical disciplines where personalized medicine has been recently becoming an important part of clinical practice. In this article, the brief overview and a number of examples of the use of biomarkers and personalized medicine in neurology are described. The various issues in neurology are described in relation to the personalized medicine and diagnostic, prognostic as well as predictive blood and cerebrospinal fluid biomarkers. Such neurological domains discussed in t...

  8. Biomarkers in precision therapy in colorectal cancer

    OpenAIRE

    Reimers, Marlies S.; Zeestraten, Eliane C.M.; Kuppen, Peter J.K.; Liefers, Gerrit Jan; van de Velde, Cornelis J. H.

    2013-01-01

    Colorectal cancer (CRC) is the most commonly diagnosed cancer in Europe. Because CRC is also a major cause of cancer-related deaths worldwide, a lot of research has been focused on the discovery and development of biomarkers to improve the diagnostic process and to predict treatment outcomes. Up till now only a few biomarkers are recommended by expert panels. Current TNM criteria, however, cause substantial under- and overtreatment of CRC patients. Consequently, there is a growing need for ne...

  9. Biomarkers of peripheral muscle fatigue during exercise

    OpenAIRE

    Finsterer Josef

    2012-01-01

    Abstract Background Biomarkers of peripheral muscle fatigue (BPMFs) are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise. Results BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxid...

  10. Breakdown study based on direct in situ observation of inner surfaces of an rf accelerating cavity during a high-gradient test

    Science.gov (United States)

    Abe, Tetsuo; Kageyama, Tatsuya; Sakai, Hiroshi; Takeuchi, Yasunao; Yoshino, Kazuo

    2016-10-01

    We have developed normal-conducting accelerating single-cell cavities with a complete higher-order-mode (HOM) heavily damped structure, into which we feed a 508.9-MHz continuous wave. During a high-gradient test of the second production version of the cavity, we performed a breakdown study based on direct in situ observation of the inner surfaces of the cavity. This paper presents our experimental findings obtained from this observation.

  11. Space platform expendables resupply concept definition study. Volume 3: Work breakdown structure and work breakdown structure dictionary

    Science.gov (United States)

    1984-01-01

    The work breakdown structure (WBS) for the Space Platform Expendables Resupply Concept Definition Study is described. The WBS consists of a list of WBS elements, a dictionary of element definitions, and an element logic diagram. The list and logic diagram identify the interrelationships of the elements. The dictionary defines the types of work that may be represented by or be classified under each specific element. The Space Platform Expendable Resupply WBS was selected mainly to support the program planning, scheduling, and costing performed in the programmatics task (task 3). The WBS is neither a statement-of-work nor a work authorization document. Rather, it is a framework around which to define requirements, plan effort, assign responsibilities, allocate and control resources, and report progress, expenditures, technical performance, and schedule performance. The WBS element definitions are independent of make-or-buy decisions, organizational structure, and activity locations unless exceptions are specifically stated.

  12. Renal biomarkers in domestic species.

    Science.gov (United States)

    Hokamp, Jessica A; Nabity, Mary B

    2016-03-01

    Current conventional tests of kidney damage and function in blood (serum creatinine and urea nitrogen) and urine (urine protein creatinine ratio and urine specific gravity) are widely used for diagnosis and monitoring of kidney disease. However, they all have important limitations, and additional markers of glomerular filtration rate and glomerular and tubular damage are desirable, particularly for earlier detection of renal disease when therapy is most effective. Additionally, urinary markers of kidney damage and function may help localize damage to the affected portion of the kidney. In general, the presence of high- and intermediate-molecular weight proteins in the urine are indicative of glomerular damage, while low-molecular weight proteins and enzymes in the urine suggest tubular damage due to decreased reabsorption of proteins, direct tubular damage, or both. This review aims to discuss many of these new blood and urinary biomarkers in domestic veterinary species, focusing primarily on dogs and cats, how they may be used for diagnosis of renal disease, and their limitations. Additionally, a brief discussion of serum creatinine is presented, highlighting its limitations and important considerations for its improved interpretation in domestic species based on past literature and recent studies. PMID:26918420

  13. Proteomic Approaches for Biomarker Panels in Cancer.

    Science.gov (United States)

    Tanase, Cristiana; Albulescu, Radu; Neagu, Monica

    2016-01-01

    Proteomic technologies remain the main backbone of biomarkers discovery in cancer. The continuous development of proteomic technologies also enlarges the bioinformatics domain, thus founding the main pillars of cancer therapy. The main source for diagnostic/prognostic/therapy monitoring biomarker panels are molecules that have a dual role, being both indicators of disease development and therapy targets. Proteomic technologies, such as mass-spectrometry approaches and protein array technologies, represent the main technologies that can depict these biomarkers. Herein, we will illustrate some of the most recent strategies for biomarker discovery in cancer, including the development of immune-markers and the use of cancer stem cells as target therapy. The challenges of proteomic biomarker discovery need new forms of cross-disciplinary conglomerates that will result in increased and tailored access to treatments for patients; diagnostic companies would benefit from the enhanced co-development of companion diagnostics and pharmaceutical companies. In the technology optimization in biomarkers, immune assays are the leaders of discovery machinery. PMID:26565430

  14. Potential Blood-based Biomarkers for Concussion.

    Science.gov (United States)

    Papa, Linda

    2016-09-01

    Mounting research in the field of sports concussion biomarkers has led to a greater understanding of the effects of brain injury from sports. A recent systematic review of clinical studies examining biomarkers of brain injury following sports-related concussion established that almost all studies have been published either in or after the year 2000. In an effort to prevent chronic traumatic encephalopathy and long-term consequences of concussion, early diagnostic and prognostic tools are becoming increasingly important; particularly in sports and in military personnel, where concussions are common occurrences. Early and tailored management of athletes following a concussion with biomarkers could provide them with the best opportunity to avoid further injury. Should blood-based biomarkers for concussion be validated and become widely available, they could have many roles. For instance, a point-of-care test could be used on the field by trained sport medicine professionals to help detect a concussion. In the clinic or hospital setting, it could be used by clinicians to determine the severity of concussion and be used to screen players for neuroimaging (computed tomography and/or magnetic resonance imaging) and further neuropsychological testing. Furthermore, biomarkers could have a role in monitoring progression of injury and recovery and in managing patients at high risk of repeated injury by being incorporated into guidelines for return to duty, work, or sports activities. There may even be a role for biomarkers as surrogate measures of efficacy in the assessment of new treatments and therapies for concussion. PMID:27482776

  15. Blood biomarker for Parkinson disease: peptoids

    Science.gov (United States)

    Yazdani, Umar; Zaman, Sayed; Hynan, Linda S; Brown, L Steven; Dewey, Richard B; Karp, David; German, Dwight C

    2016-01-01

    Parkinson disease (PD) is the second most common neurodegenerative disease. Because dopaminergic neuronal loss begins years before motor symptoms appear, a biomarker for the early identification of the disease is critical for the study of putative neuroprotective therapies. Brain imaging of the nigrostriatal dopamine system has been used as a biomarker for early disease along with cerebrospinal fluid analysis of α-synuclein, but a less costly and relatively non-invasive biomarker would be optimal. We sought to identify an antibody biomarker in the blood of PD patients using a combinatorial peptoid library approach. We examined serum samples from 75 PD patients, 25 de novo PD patients, and 104 normal control subjects in the NINDS Parkinson’s Disease Biomarker Program. We identified a peptoid, PD2, which binds significantly higher levels of IgG3 antibody in PD versus control subjects (P<0.0001) and is 68% accurate in identifying PD. The PD2 peptoid is 84% accurate in identifying de novo PD. Also, IgG3 levels are significantly higher in PD versus control serum (P<0.001). Finally, PD2 levels are positively correlated with the United Parkinson’s Disease Rating Scale score (r = 0.457, P<0001), a marker of disease severity. The PD2 peptoid may be useful for the early-stage identification of PD, and serve as an indicator of disease severity. Additional studies are needed to validate this PD biomarker. PMID:27812535

  16. Biomarker-based dissection of neurodegenerative diseases.

    Science.gov (United States)

    Olsson, Bob; Zetterberg, Henrik; Hampel, Harald; Blennow, Kaj

    2011-12-01

    The diagnosis of neurodegenerative diseases within neurology and psychiatry are hampered by the difficulty in getting biopsies and thereby validating the diagnosis by pathological findings. Biomarkers for other types of disease have been readily adopted into the clinical practice where for instance troponins are standard tests when myocardial infarction is suspected. However, the use of biomarkers for neurodegeneration has not been fully incorporated into the clinical routine. With the development of cerebrospinal fluid (CSF) biomarkers that reflect pathological events within the central nervous system (CNS), important clinical diagnostic tools are becoming available. This review summarizes the most promising biomarker candidates that may be used to monitor different types of neurodegeneration and protein inclusions, as well as different types of metabolic changes, in living patients in relation to the clinical phenotype and disease progression over time. Our aim is to provide the reader with an updated lexicon on currently available biomarker candidates, how far they have come in development and how well they reflect pathogenic processes in different neurodegenerative diseases. Biomarkers for specific pathogenetic processes would also be valuable tools both to study disease pathogenesis directly in patients and to identify and monitor the effect of novel treatment strategies.

  17. The use of biomarkers in clinical osteoporosis.

    Science.gov (United States)

    Cabral, Hebert Wilson Santos; Andolphi, Bruna Ferreira Galone; Ferreira, Brunna Vila Coutinho; Alves, Danielle Cristina Filgueira; Morelato, Renato Lírio; Chambo, Antônio; Borges, Lizânia Spinassé

    2016-07-01

    Osteoporosis is a disease of ascending character in the world population; in this context, bone biomarkers are being increasingly studied in order to aid in the diagnosis and monitoring of these patients. The main objective of this study was a literature review of articles whose main theme was the use of biomarkers for bone formation and degradation, and to evaluate their possible applicability in clinical practice. Literature review was performed through articles indexed and published in the last five years in the PubMed database. The findings of this study showed that most of the previously selected articles were published in the last two years, and the most cited markers were bone resorption, C-terminal collagen telopeptide (CTX), showing the highest correlation with the dynamics of bone, and the biomarker of bone formation, bone-specific alkaline phosphatase (BAP), which is increased in the event of fracture or may suggest another bone disease. There was an increase in published articles, associating different bone biomarkers and their clinical applicability, especially for treatment control. Our findings suggest that in recent years there has been significant increase in publications evaluating the use of bone turnover biomarkers for bone formation and resorption and their possible clinical applicability, especially in the monitoring of treatment. Still, we believe that further studies need to be conducted to confirm these findings, given the advantages that bone biomarkers can deliver in the clinical management of the disease.

  18. Paleo-reconstruction: Using multiple biomarker parameters

    Science.gov (United States)

    Chen, Zhengzheng

    Advanced technologies have played essential roles in the development of molecular organic geochemistry. In this thesis, we have developed several new techniques and explored their applications, alone and with previous techniques, to paleo-reconstruction. First, we developed a protocol to separate biomarker fractions for accurate measurement of compound-specific isotope analysis. This protocol involves combination of zeolite adduction and HPLC separation. Second, an integrated study of traditional biomarker parameters, diamondoids and compound-specific biomarker isotopes, differentiated oil groups from Saudi Arabia. Specifically, Cretaceous reservoired oils were divided into three groups and the Jurassic reservoired oils were divided into two groups. Third, biomarker acids provide an alternative way to characterize biodegradation. Oils from San Joaquin Valley, U.S.A. and oils from Mediterranean display drastically different acid profiles. These differences in biomarker acids probably reflect different processes of biodegradation. Fourth, by analyzing biomarker distributions in the organic-rich rocks recording the onset of Late Ordovician extinction, we propose that changes in salinity associated with eustatic sea-level fall, contributed at least locally to the extinction of graptolite species.

  19. Composite-step product methods for solving nonsymmetric linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Chan, T.F.; Szeto, T. [Univ. of California, Los Angeles, CA (United States)

    1994-12-31

    The Biconjugate Gradient (BCG) algorithm is the {open_quotes}natural{close_quotes} generalization of the classical Conjugate Gradient method to nonsymmetric linear systems. It is an attractive method because of its simplicity and its good convergence properties. Unfortunately, BCG suffers from two kinds of breakdowns (divisions by 0): one due to the non-existence of the residual polynomial, and the other due to a breakdown in the recurrence relationship used. There are many look-ahead techniques in existence which are designed to handle these breakdowns. Although the step size needed to overcome an exact breakdown can be computed in principle, these methods can unfortunately be quite complicated for handling near breakdowns since the sizes of the look-ahead steps are variable (indeed, the breakdowns can be incurable). Recently, Bank and Chan introduced the Composite Step Biconjugate Gradient (CSBCG) algorithm, an alternative which cures only the first of the two breakdowns mentioned by skipping over steps for which the BCG iterate is not defined. This is done with a simple modification of BCG which needs only a maximum look-ahead step size of 2 to eliminate the (near) breakdown and to smooth the sometimes erratic convergence of BCG. Thus, instead of a more complicated (but less prone to breakdown) version, CSBCG cures only one kind of breakdown, but does so with a minimal modification to the usual implementation of BCG in the hope that its empirically observed stability will be inherited. The authors note, then, that the Composite Step idea can be incorporated anywhere the BCG polynomial is used; in particular, in product methods such as CGS, Bi-CGSTAB, and TFQMR. Doing this not only cures the breakdown mentioned above, but also takes on the advantages of these product methods, namely, no multiplications by the transpose matrix and a faster convergence rate than BCG.

  20. New serological biomarkers of inflammatory bowel disease.

    Science.gov (United States)

    Li, Xuhang; Conklin, Laurie; Alex, Philip

    2008-09-01

    Serological biomarkers in inflammatory bowel disease (IBD) are a rapidly expanding list of non-invasive tests for objective assessments of disease activity, early diagnosis, prognosis evaluation and surveillance. This review summarizes both old and new biomarkers in IBD, but focuses on the development and characterization of new serological biomarkers (identified since 2007). These include five new anti-glycan antibodies, anti-chitobioside IgA (ACCA), anti-laminaribioside IgG (ALCA), anti-manobioside IgG (AMCA), and antibodies against chemically synthesized (Sigma) two major oligomannose epitopes, Man alpha-1,3 Man alpha-1,2 Man (SigmaMan3) and Man alpha-1,3 Man alpha-1,2 Man alpha-1,2 Man (SigmaMan4). These new biomarkers serve as valuable complementary tools to existing biomarkers not only in differentiating Crohn's disease (CD), ulcerative colitis (UC), normal and other non-IBD gut diseases, but also in predicting disease involvement (ileum vs colon), IBD risk (as subclinical biomarkers), and disease course (risk of complication and surgery). Interestingly, the prevalence of the antiglycan antibodies, including anti-Saccharomyces cerevisiae antibodies (ASCA), ALCA and AMCA, was found to be associated with single nucleotide polymorphisms (SNPs) of IBD susceptible genes such as NOD2/CARD15, NOD1/CARD4, toll-like receptors (TLR) 2 and 4, and beta-defensin-1. Furthermore, a gene dosage effect was observed: anti-glycan positivity became more frequent as the number of NOD2/CARD15 SNPS increased. Other new serum/plasma IBD biomarkers reviewed include ubiquitination factor E4A (UBE4A), CXCL16 (a chemokine), resistin, and apolipoprotein A-IV. This review also discusses the most recent studies in IBD biomarker discovery by the application of new technologies such as proteomics, fourier transform near-infrared spectroscopy, and multiplex enzyme-linked immunosorbent assay (ELISA)'s (with an emphasis on cytokine/chemokine profiling). Finally, the prospects of developing more

  1. Determination of whey adulteration in milk powder by using laser induced breakdown spectroscopy.

    Science.gov (United States)

    Bilge, Gonca; Sezer, Banu; Eseller, Kemal Efe; Berberoglu, Halil; Topcu, Ali; Boyaci, Ismail Hakki

    2016-12-01

    A rapid and in situ method has been developed to detect and quantify adulterated milk powder through adding whey powder by using laser induced breakdown spectroscopy (LIBS). The methodology is based on elemental composition differences between milk and whey products. Milk powder, sweet and acid whey powders were produced as standard samples, and milk powder was adulterated with whey powders. Based on LIBS spectra of standard samples and commercial products, species was identified using principle component analysis (PCA) method, and discrimination rate of milk and whey powders was found as 80.5%. Calibration curves were obtained with partial least squares regression (PLS). Correlation coefficient (R(2)) and limit of detection (LOD) values were 0.981 and 1.55% for adulteration with sweet whey powder, and 0.985 and 0.55% for adulteration with acid whey powder, respectively. The results were found to be consistent with the data from inductively coupled plasma - mass spectrometer (ICP-MS) method. PMID:27374522

  2. Double-pulse laser-induced breakdown spectroscopy analysis of scales from petroleum pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, G.H. [Physics Department of University Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n" o – CEP 24210-346 – Niterói, Rio de Janeiro (Brazil); Rocha, A.A. [Department of Analytical Chemistry of the Fluminense Federal University (UFF), Niterói, Rio de Janeiro CEP: 24020-141 (Brazil); Damasceno, R.N. [Biomass and Water Research Center of the Fluminense Federal University (NAB/UFF), Niterói, Rio de Janeiro (Brazil); Legnaioli, S.; Lorenzetti, G.; Pardini, L. [Institute of Chemistry of Organometallic Compounds Of CNR, Research Area of National Research Council, Via G. Moruzzi, 1 — 56124 Pisa (Italy); Palleschi, V., E-mail: vincenzo.palleschi@cnr.it [Institute of Chemistry of Organometallic Compounds Of CNR, Research Area of National Research Council, Via G. Moruzzi, 1 — 56124 Pisa (Italy)

    2013-09-01

    Pipeline scales from the Campos Bay Petroleum Field near Rio de Janeiro, Brazil have been analyzed by both Raman spectroscopy and by laser-induced breakdown spectroscopy (LIBS) using a double-pulse, calibration-free approach. Elements that are characteristic of petroleum (e.g. C, H, N, O, Mg, Na, Fe and V) were detected, in addition to the Ca, Al, and Si which form the matrix of the scale. The LIBS results were compared with the results of micro-Raman spectroscopy, which confirmed the nature of the incrustations inferred by the LIBS analysis. Results of this preliminary study suggest that diffusion of pipe material into the pipeline intake column plays an important role in the growth of scale. Thanks to the simplicity and relative low cost of equipment and to the fact that no special chemical pre-treatment of the samples is needed, LIBS can offer very fast acquisition of data and the possibility of in situ measurements. LIBS could thus represent an alternative or complementary method for the chemical characterization of the scales by comparison to conventional analytical techniques, such as X-ray diffraction or X-ray fluorescence. - Highlights: • Samples of scales from petroleum pipelines were analyzed using double pulse LIBS. • LIBS is proposed as an alternative method to conventional analytical techniques. • The scale growth is influenced by the product of corrosion in the column of production. • The diffusion of pipe material into the inlay is important for the growth of scale.

  3. Breakdown and space charge formation in polyimide film under DC high stress at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, Y; Hashimoto, T; Miyake, H; Tanaka, Y; Takada, T, E-mail: ytanaka@tcu.ac.j [Tokyo City University, 1-28-1, Tamatsutsumi, Setagaya-ku, Tokyo (Japan)

    2009-08-01

    Relationship between breakdown strength and space charge formation in polyimide film under dc high stress at various temperatures is investigated using pulsed electro-acoustic (PEA) method. Some typical results of the space charge observations show that hetero space charges are always found before breakdown. The amount of the hetero charges increase with increase of temperature or increase of applied electric field. Since the enhancement of the internal electric field in the sample by the accumulation of the hetero charges is not so large, the accumulation doesn't seem to be an immediate cause of breakdown. However since it is always observed before breakdown, it may be predictive information for breakdown. In a certain case, the breakdown occurs after voltage application for few hours. However, while we give an interval of short circuit condition after observing the hetero space charge under dc stress, the total voltage application time to breakdown is almost the same to the case without the interval. It means that the hetero space charge generation may show a kind of degradation of the material.

  4. Positive and negative effects of dielectric breakdown in transformer oil based magnetic fluids

    International Nuclear Information System (INIS)

    The transformer oil based magnetic fluids can be considered as the next-generation insulation fluids because they offer exciting new possibilities to enhance dielectric breakdown voltage as well as heat transfer performance compared to pure transformer oils. In this study, we have investigated the dielectric breakdown strength of the fluids with the various volume concentrations of nanoparticles in accordance with IEC 156 standard and have tried to find the reason for changing the dielectric breakdown voltage of the fluids from the magnetic field analysis. It was found that the dielectric breakdown voltage of pure transformer oil is around 12 kV with the gap distance of 1.5 mm. In the case of our transformer oil-based magnetic fluids with 0.08% < Φ < 0.6% (Φ means the volume concentration of magnetic nanoparticles), the dielectric breakdown voltage shows above 40 kV, which is 3.3 times higher positively than that of pure transformer oil. Negatively in the case when the volume concentration of magnetic nanoparticles is above 0.65%, the dielectric breakdown voltage decreases reversely. From the magnetic field analysis, the reason might be considered as two situations: the positive is for the conductive nanoparticles dispersed well near the electrodes, which play an important role in converting fast electrons to slow negatively charged particles, and the negative is for the agglomeration of the particles near the electrodes, which leads to the breakdown initiation.

  5. Effects of elevated temperature on protein breakdown in muscles from septic rats

    International Nuclear Information System (INIS)

    Elevated temperature has been proposed to contribute to accelerated muscle protein degradation during fever and sepsis. The present study examined the effect of increased temperature in vitro on protein turnover in skeletal muscles from septic and control rats. Sepsis was induced by cecal ligation and puncture (CLP); control rats were sham operated. After 16 h, the extensor digitorum longus (EDL) and soleus (SOL) muscles were incubated at 37 or 40 degrees C. Protein synthesis was determined by measuring incorporation of [14C]phenylalanine into protein. Total and myofibrillar protein breakdown was assessed from release of tyrosine and 3-methylhistidine (3-MH), respectively. Total protein breakdown was increased at 40 degrees C by 15% in EDL and by 29% in SOL from control rats, whereas 3-MH release was not affected. In muscles from septic rats, total and myofibrillar protein breakdown was increased by 22 and 30%, respectively, at 40 degrees C in EDL but was not altered in SOL. Protein synthesis was unaffected by high temperature both in septic and nonseptic muscles. The present results suggest that high temperature is not the primary mechanism of increased muscle protein breakdown in sepsis because the typical response to sepsis, i.e., a predominant increase in myofibrillar protein breakdown, was not induced by elevated temperature in normal muscle. It is possible, however, that increased temperature may potentiate protein breakdown that is already stimulated by sepsis because elevated temperature increased both total and myofibrillar protein breakdown in EDL from septic rats

  6. Influence of temperature and electrode size on breakdown characteristics in saturated superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Suehiro, Junya; Takahashi, Takuji; Miyama, Motohide; Hara, Masanori [Kyushu Univ., Fukuoka (Japan)

    1997-06-01

    Dc breakdown strength and pulsed breakdown time lag of saturated superfluid liquid helium (HeII) at 1.4 K and 1.85 K are measured over a wide range of electrode size and applied field strength. The results of the measurements are statistically analyzed by using Weibull distribution functions. It is found that area effect is dominant for dc and pulsed breakdown rather than volume effect as in the case of liquid helium of 4.2 K (HeI). A shape parameter in the Weibull distribution function for dc breakdown strength of HeII is smaller than that of HeI. As a result, dc breakdown in superfluid helium can take place in a wider electrode area than in normal liquid helium, while no remarkable difference in breakdown area are observed between 1.85 K and 1.4 K. On the other hand, the statistical time lag in HeII becomes shorter with temperature decrease. According to Fowler-Nordheim theory, it is suggested that a higher electron mobility in HeII may increase the field emitted electron kinetic energy to trigger the liquid breakdown with a higher probability. (author)

  7. CO2 laser breakdown and heating of hydrogen in a magnetic mirror field

    International Nuclear Information System (INIS)

    A 1-GW, 125-J CO2-laser pulse focussed by a 10-cm focal-length parabolic mirror has been used to induce breakdown and heating in 15-torr hydrogen along the axis of a short 50-kGauss magnetic mirror field. Evolution of the breakdown plasma thus produced has been studied by high-speed photography, ruby-laser Thomson scattering and a Mach-Zehnder interferometer. Results indicate an efficient radial confinement of plasma by the mirror field with an electron temperature much enhanced over that resulting from a field-free breakdown. An electron temperature of approximately 100 eV has been measured near the laser focus at the end of the gain-switched CO2-laser spike in the mirror field compared to approximately 20 eV at the same time in a field-free breakdown. Interferometric measurements show that breakdown results in a cylindrical plasma with an electron density minimum on axis in both cases. A monitor of the transmitted CO2-laser pulse indicates very incomplete coupling of laser radiation into the plasma column with the field applied, presumably because of fraction losses at the entrance boundary of the breakdown. Experimental results agree qualitatively at early times with a numerical hydrodynamic calculation which neglects axial plasma expansion and assumes complete coupling of the laser into the breakdown column. (author)

  8. Breakdown in the Organ Donation Process and Its Effect on Organ Availability

    Directory of Open Access Journals (Sweden)

    Manik Razdan

    2015-01-01

    Full Text Available Background. This study examines the effect of breakdown in the organ donation process on the availability of transplantable organs. A process breakdown is defined as a deviation from the organ donation protocol that may jeopardize organ recovery. Methods. A retrospective analysis of donation-eligible decedents was conducted using data from an independent organ procurement organization. Adjusted effect of process breakdown on organs transplanted from an eligible decedent was examined using multivariable zero-inflated Poisson regression. Results. An eligible decedent is four times more likely to become an organ donor when there is no process breakdown (adjusted OR: 4.01; 95% CI: 1.6838, 9.6414; P<0.01 even after controlling for the decedent’s age, gender, race, and whether or not a decedent had joined the state donor registry. However once the eligible decedent becomes a donor, whether or not there was a process breakdown does not affect the number of transplantable organs yielded. Overall, for every process breakdown occurring in the care of an eligible decedent, one less organ is available for transplant. Decedent’s age is a strong predictor of likelihood of donation and the number of organs transplanted from a donor. Conclusion. Eliminating breakdowns in the donation process can potentially increase the number of organs available for transplant but some organs will still be lost.

  9. Breakdown Voltage Research of Penning Gas Mixture in Plasma Display Panel

    Institute of Scientific and Technical Information of China (English)

    Guo Bingang; Liu Chunliang; Song Zhongxiao; Fan Yufeng; Xia Xing; Liu Liu; Fan Duowang

    2005-01-01

    Paschen law and equations, which ignore the influence of the Penning ionization on the electron ionization coefficient (α), are always used as the approximation of the breakdown voltage criterion of the Penning gas mixture in current researches of discharge characteristics of the plasma display panel (PDP). It is doubtful that whether their results match the facts. Based on the Townsend gas self-sustaining discharge condition and the chemical kinetics analysis of the Penning gas mixture discharging in PDP, the empirical equation to describe the breakdown of the Penning gas mixture is given. It is used to calculate the breakdown voltage curves of Ne-Xe/MgO and Ne-Ar/MgO in a testing macroscopic discharge cell of AC-PDP. The effective secondary electron emission coefficients (γeff) of the MgO protective layers are derived by comparing the breakdown voltage curves obtained from the empirical equation with the experimental data of breakdown voltages. In comparison with the results calculated by the Paschen law and the equation which ignore the influence of the Penning ionization on α , the results calculated by the empirical equation have better conformity with experimental data. The empirical equation characterizes the breakdown of the Penning gas mixture in PDP effectively, and gives a convenient way to study its breakdown characteristics and the secondary electron emission behaviors.

  10. Scaling and volatility of breakouts and breakdowns in stock price dynamics.

    Directory of Open Access Journals (Sweden)

    Lu Liu

    Full Text Available BACKGROUND: Because the movement of stock prices is not only ubiquitous in financial markets but also crucial for investors, extensive studies have been done to understand the law behind it. In particular, since the financial crisis in 2008, researchers have a more interest in investigating large market volatilities in order to grasp changing market trends. METHODOLOGY/PRINCIPAL FINDINGS: In this work, we analyze the breakouts and breakdowns of both the Standard & Poor's 500 Index in the US stock market and the Shanghai Composite Index in the Chinese stock market. The breakout usually represents an ongoing upward trend in technical analysis while the breakdown represents an ongoing downward trend. Based on the renormalization method, we introduce two parameters to quantize breakouts and breakdowns, respectively. We discover scaling behavior, characterized by power-law distributions for both the breakouts and breakdowns in the two financial markets with different power-law exponents, which reflect different market volatilities. In detail, the market volatility for breakdowns is usually larger than that for breakouts. Moreover, as an emerging market, the Chinese stock market has larger market volatilities for both the breakouts and breakdowns than the US stock market (a mature market. Further, the short-term volatilities show similar features for both the US stock market and the Chinese stock market. However, the medium-term volatilities in the US stock market are almost symmetrical for the breakouts and breakdowns, whereas those in the Chinese stock market appear to be asymmetrical for the breakouts and breakdowns. CONCLUSIONS/SIGNIFICANCE: The methodology presented here provides a way to understand scaling and hence volatilities of breakouts and breakdowns in stock price dynamics. Our findings not only reveal the features of market volatilities but also make a comparison between mature and emerging financial markets.

  11. Measurements of electron avalanche formation time in W-band microwave air breakdown

    International Nuclear Information System (INIS)

    We present measurements of formation times of electron avalanche ionization discharges induced by a focused 110 GHz millimeter-wave beam in atmospheric air. Discharges take place in a free volume of gas, with no nearby surfaces or objects. When the incident field amplitude is near the breakdown threshold for pulsed conditions, measured formation times are ∼0.1-2 μs over the pressure range 5-700 Torr. Combined with electric field breakdown threshold measurements, the formation time data shows the agreement of 110 GHz air breakdown with the similarity laws of gas discharges.

  12. Scaling laws for gas breakdown for nanoscale to microscale gaps at atmospheric pressure

    Science.gov (United States)

    Loveless, Amanda M.; Garner, Allen L.

    2016-06-01

    Electronics miniaturization motivates gas breakdown predictions for microscale and smaller gaps, since traditional breakdown theory fails when gap size, d, is smaller than ˜15 μm at atmospheric pressure, patm. We perform a matched asymptotic analysis to derive analytic expressions for breakdown voltage, Vb, at patm for 1 nm ≤ d ≤ 35 μm. We obtain excellent agreement between numerical, analytic, and particle-in-cell simulations for argon, and show Vb decreasing as d → 0, instead of increasing as predicted by Paschen's law. This work provides an analytic framework for determining Vb at atmospheric pressure for various gap distances that may be extended to other gases.

  13. A three-dimensional breakdown model of SOI lateral power transistors with a circular layout

    Institute of Scientific and Technical Information of China (English)

    Guo Yufeng; Wang Zhigong; Sheu Gene

    2009-01-01

    This paper presents an analytical three-dimensional breakdown model of SOl lateral power devices with a circular layout. The Poisson equation is solved in cylindrical coordinates to obtain the radial surface potential and electric field distributions for both fully- and partially-depleted drift regions. The breakdown voltages for N~+N and P~+N junctions are derived and employed to investigate the impact of cathode region curvature. A modified RESURF criterion is proposed to provide a design guideline for optimizing the breakdown voltage and doping concentration in the drift region in three dimensional space. The analytical results agree well with MEDICI simulation results and experimental data from earlier publications.

  14. Measurements of electron avalanche formation time in W-band microwave air breakdown

    Science.gov (United States)

    Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J.

    2011-08-01

    We present measurements of formation times of electron avalanche ionization discharges induced by a focused 110 GHz millimeter-wave beam in atmospheric air. Discharges take place in a free volume of gas, with no nearby surfaces or objects. When the incident field amplitude is near the breakdown threshold for pulsed conditions, measured formation times are ˜0.1-2 μs over the pressure range 5-700 Torr. Combined with electric field breakdown threshold measurements, the formation time data shows the agreement of 110 GHz air breakdown with the similarity laws of gas discharges.

  15. Breakdown voltage reduction by field emission in multi-walled carbon nanotubes based ionization gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Saheed, M. Shuaib M.; Muti Mohamed, Norani; Arif Burhanudin, Zainal, E-mail: zainabh@petronas.com.my [Centre of Innovative Nanostructures and Nanodevices, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2014-03-24

    Ionization gas sensors using vertically aligned multi-wall carbon nanotubes (MWCNT) are demonstrated. The sharp tips of the nanotubes generate large non-uniform electric fields at relatively low applied voltage. The enhancement of the electric field results in field emission of electrons that dominates the breakdown mechanism in gas sensor with gap spacing below 14 μm. More than 90% reduction in breakdown voltage is observed for sensors with MWCNT and 7 μm gap spacing. Transition of breakdown mechanism, dominated by avalanche electrons to field emission electrons, as decreasing gap spacing is also observed and discussed.

  16. Effect of UV radiation on the growth and breakdown voltage of anodic oxide films on niobium

    International Nuclear Information System (INIS)

    Formation rates of anodic Nb2O5 films grown under galvanostatic conditions decrease in the presence of UV radiation, unlike those grown in the absence of UV radiation. This may be due to the development of a positive space charge near the solution/oxide interface which is responsible for an increase in electronic current in the film during its formation. Value of breakdown voltage also increases in the presence of UV radiations. The effect of current density and resistivity of the solution upon the breakdown voltage, both in the presence and absence of UV radiation, is discussed in terms of Ikonopisov theory of breakdown voltage. (author). 19 refs., 6 figs

  17. JOINT INVESTIGATION OF ROTATING FLOW WITH VORTEX BREAKDOWN USING CFD, VISUALIZATION AND LDV

    Institute of Scientific and Technical Information of China (English)

    LIU Ying-zheng; CHEN Han-ping; KOYAMA Hide S.

    2005-01-01

    Vortex breakdown of the steady axisymmetic rotating flow in a confined cylindrical container with a rotating endwall was numerically and experimentally studied. High-quality precision-controlled turntable facilities were established at Shanghai Jiaotong University and Tokyo Denki University independently. Collaborative investigations of vortex breakdown were carried out using CFD, Laser Doppler Velocimetry (LDV) and streakline visualization, respectively. The characteristics of vortex breakdown were delineated in terms of comparative investigation using numerical and experimental results. SIMPLEC scheme and FMG multigrid was applied to numerical simulation. Numerical simulation was extensively compared with streakline visualization and LDV measurements, showing qualitative and quantitative agreements.

  18. Effects of organically and conventionally produced feed on biomarkers of health in a chicken model

    NARCIS (Netherlands)

    Huber, M.; Vijver, van de L.P.L.; Parmentier, H.K.; Savelkoul, H.F.J.; Coulier, L.; Wopereis, S.; Verheij, E.; Greef, de J.; Nierop, D.; Hoogenboom, R.A.P.

    2010-01-01

    Consumers expect organic products to be healthier. However, limited research has been performed to study the effect of organic food on health. The present study aimed to identify biomarkers of health to enable future studies in human subjects. A feeding experiment was performed in two generations of

  19. Single machine stochastic JIT scheduling problem subject to machine breakdowns

    Institute of Scientific and Technical Information of China (English)

    TANG HengYong; ZHAO ChuanLi; CHENG CongDian

    2008-01-01

    In this paper we research the single machine stochastic JIT scheduling problem subject to the machine breakdowns for preemptive-resume and preemptive-repeat. The objective function of the problem is the sum of squared deviations of the job-expected completion times from the due date. For preemptive-resume, we show that the optimal sequence of the SSDE problem is V-shaped with respect to expected processing times. And a dynamic programming algorithm with the pseudopolynomial time complexity is, given. We discuss the difference between the SSDE problem and the ESSD problem and show that the optimal solution of the SSDE problem is a good approximate optimal solution of the ESSD problem, and the optimal solution of the SSDE problem is an optimal solution of the ESSD problem under some conditions. For preemptive-repeat, the stochastic JIT scheduling problem has not been solved since the variances of the completion times cannot be computed. We replace the ESSD problem by the SSDE problem. We show that the optimal sequence of the SSDE problem is V-shaped with respect to the expected occupying times. And a dynamic programming algorithm with the pseudopolynomial time complexity is given. A new thought is advanced for the research of the preemptive-repeat stochastic JIT scheduling problem.

  20. Single machine stochastic JIT scheduling problem subject to machine breakdowns

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper we research the single machine stochastic JIT scheduling problem subject to the machine breakdowns for preemptive-resume and preemptive-repeat.The objective function of the problem is the sum of squared deviations of the job-expected completion times from the due date.For preemptive-resume,we show that the optimal sequence of the SSDE problem is V-shaped with respect to expected processing times.And a dynamic programming algorithm with the pseudopolynomial time complexity is given.We discuss the difference between the SSDE problem and the ESSD problem and show that the optimal solution of the SSDE problem is a good approximate optimal solution of the ESSD problem,and the optimal solution of the SSDE problem is an optimal solution of the ESSD problem under some conditions.For preemptive-repeat,the stochastic JIT scheduling problem has not been solved since the variances of the completion times cannot be computed.We replace the ESSD problem by the SSDE problem.We show that the optimal sequence of the SSDE problem is V-shaped with respect to the expected occupying times.And a dynamic programming algorithm with the pseudopolynomial time complexity is given.A new thought is advanced for the research of the preemptive-repeat stochastic JIT scheduling problem.